M Mich ricul Agr higan ltur n St ral E tate xper Univ rimen vers nt St sity on tatio In C Mic In ndus Coope higa try eratio an P Com on Wit Pota mmis th ato ssion n otato Volu o Res ume sear 42 rch R Repor rt Mic chiga an Po 20 010 0 Michigan Potato Industry Commission 13109 Schavey Rd., Ste. 7 DeWitt, MI 48820 517.669.8377 Fax 517.669.8377 www.mipotato.com email: info@mipotato.com April 2011 To All Michigan Potato Growers & Shippers: The Michigan Potato Industry Commission, Michigan State University’s AgBioResearch and Cooperative Extension Service are pleased to provide you with a copy of the results from the 2010 potato research projects. This report includes research projects funded by the Michigan Potato Industry Commission, the USDA Special Grant and special allocations by the Commission. Additionally, the Commission expresses appreciation to suppliers of products for research purposes and special grants to the Commission and researchers. Providing research funding and direction to principal investigators at MSU is a function of the Michigan Potato Industry Commission’s Research Committee. Best wishes for a prosperous 2011 season. Pat DuRussel, Chairman Brian Sackett, Vice Chairman Duane Andersen Dennis Hanson Greg Iott Randy Styma Tim Wilkes Tim Young Ex Officios: Keith Creagh, MDA Dr. Dave Douches, MSU Table of Contents Page 1 6 29 58 76 81 83 87 93 100 102 Introduction and Acknowledgements 2010 Potato Breeding and Genetics Research Report David S. Douches, J. Coombs, K. Zarka, G. Steere, M. Zuehlke, D. Zarka, K. Felcher and D. Kells 2010 Potato Variety Evaluations D.S. Douches, J. Coombs, K. Zarka, G. Steere, M. Zuehlke, C. Long, W. Kirk and J. Hao 2010 On-Farm Potato Variety Trials Chris Long, Dr. Dave Douches, Dr. Doo-Hong Min and Chris Kapp (Upper Peninsula) 2010 Weed Control Projects in Potato Dr. Wesley J. Everman, Andrew J. Chomas and Chris Long Soil treatments for control of Verticillium wilt and Common Scab of potatoes, 2010. W. W. Kirk, R. L Schafer, C. Huthinson and C. Furman Seed treatments and seed plus in furrow treatments for control of seed- and soil-borne Rhizoctonia solani, 2010. W. W. Kirk, J. Hao, R. L Schafer and P. Tumbalam Impact of different US genotypes of Phytophthora infestans on potato seed tuber rot and plant emergence in different cultivars and breeding lines Kirk, W., Rojas, A., Abu-El Samen, F., Tumbalam, P., Wharton, P., Douches, D., Thill, C.A., Thompson, A. COLORADO POTATO BEETLE RESEARCH UPDATE Zsofia Szendrei and Adam Byrne Evaluation of fungicide programs for potato early blight, brown leaf spot and tan spot control: 2010. W. W. Kirk, R. L Schafer and P. Tumbalam Population characterization of P. infestans in Michigan during 2008 to 2010 Rojas A., Kirk W.W. Evaluation of fungicide programs for potato late blight control: 2010. W. W. Kirk, R. L Schafer, A. Rojas and P. Tumbalam, Effect of different genotypes of Phytophthora infestans (Mont. de Bary) and temperature on tuber disease development Kirk W.W., Rojas A., Tumbalam P., Gachango E., Wharton P.S. , Abu-El Samen F.,Douches, D., Coombs, J., Thill, C.A., Thompson, A. Evaluation of fungicide programs for Pythium leak control, 2010. W. W. Kirk, R. L Schafer and P. Tumbalam. Fusarium Species Responsible for Dry Rot of Seed Potato Tubers in Michigan Esther Gachango, W. Kirk, L. Hanson, A. Rojas, and P. Tumbalam Managing potato common scab using biomaterials and beneficial microorganisms Jianjun Hao, William Kirk, David Douches, Qingxiao Meng, and Noah Rosenzweig 2010 Research Summary Loren G. Wernette and George W. Bird 2009-2010 Dr. B. F. (Burt) Cargill Potato Demonstration Storage Annual Report, Michigan Potato Industry Commission Chris Long, Coordinator 113 116 122 124 129 135 141 2010 MICHIGAN POTATO RESEARCH REPORT C. M. Long, Coordinator INTRODUCTION AND ACKNOWLEDGMENTS The 2010 Potato Research Report contains reports of the many potato research projects conducted by MSU potato researchers at several locations. The 2010 report is the 42nd volume, which has been prepared annually since 1969. This volume includes research projects funded by the Potato Special Federal Grant, the Michigan Potato Industry Commission (MPIC), GREEEN and numerous other sources. The principal source of funding for each project has been noted at the beginning of each report. We wish to acknowledge the excellent cooperation of the Michigan potato industry and the MPIC for their continued support of the MSU potato research program. We also want to acknowledge the significant impact that the funds from the Potato Special Federal Grant have had on the scope and magnitude of potato related research in Michigan. Many other contributions to MSU potato research have been made in the form of fertilizers, pesticides, seed, supplies and monetary grants. We also recognize the tremendous cooperation of individual producers who participate in the numerous on-farm projects. It is this dedicated support and cooperation that makes for a productive research program for the betterment of the Michigan potato industry. We further acknowledge the professionalism of the MPIC Research Committee. The Michigan potato industry should be proud of the dedication of this committee and the keen interest they take in determining the needs and direction of Michigan's potato research. Special thanks go to Bruce Sackett for the management of the MSU Montcalm Research Farm (MRF) and the many details which are a part of its operation. We also want to recognize Barb Smith at MPIC for helping with the details of this final draft. WEATHER The overall 6-month average maximum temperature during the 2010 growing season was three degrees higher than the 6-month average maximum temperature for the 2009 season and was two degrees higher than the 15-year average (Table 1). The 6-month average minimum temperature for 2010 was three degrees higher than the 15-year average. There were no recorded temperature readings of 90 °F or above in 2010. There were 220 hours of 70 °F temperatures between the hours of 10 PM and 8 AM which occurred over 43 different days, April to September (Data not shown). There were two days in May that the air temperature was below 32 °F. This occurred on May 9th and 10th. The average maximum temperatures for July and August, 2010, were two and three degrees higher than the 15-year average, respectively (Table 1). In October 2010, there were 8 days with measureable rainfall and two daytime highs below 50 °F. Rainfall for April through September was 15.13 inches, which was 3.81 inches below the 15-year average (Table 2). In October 2010, 1.45 inches of rain were recorded. Irrigation at MRF was applied 11 times from June 16th to August 16th, averaging 0.77 inches for each application. The total amount of irrigation water applied during this time period was 8.45 inches. 1 Table 1. Table 2. The 15-year summary of average maximum and minimum temperatures (°F) during the growing season at the Montcalm Research Farm. May June July August September April 6-Month Average Year Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. 50 1996 48 1997 52 1998 1999 51 50 2000 53 2001 2002 51 49 2003 49 2004 51 2005 2006 51 50 2007 49 2008 2009 49 2010 53 15-Year Average 58 75 79 77 77 75 78 79 77 74 82 78 82 77 76 77 70 69 76 73 70 69 77 72 78 77 68 76 73 74 69 80 73 81 76 79 72 81 82 76 81 80 80 80 76 82 79 59 55 60 56 57 70 58 58 53 58 58 58 54 56 61 58 76 80 82 84 77 83 85 81 79 82 83 81 80 75 83 81 57 56 56 55 57 57 58 52 54 60 54 54 56 54 57 56 44 39 51 48 49 49 42 44 46 41 46 47 40 45 49 45 31 31 37 37 34 37 36 33 37 36 36 33 37 34 38 35 64 59 75 71 70 70 63 64 67 65 61 73 67 67 70 67 51 50 52 48 49 48 52 48 49 51 48 50 50 49 50 50 69 69 75 73 71 72 73 72 73 75 72 74 73 71 74 72 50 54 60 59 56 61 56 56 62 62 62 53 61 56 64 55 57 58 62 56 58 62 58 57 58 61 56 58 53 62 58 78 73 50 The 15-year summary of precipitation (inches per month) recorded during the growing season at the Montcalm Research Farm. Year 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 15-Year Average April 2.46 2.02 2.40 5.49 3.18 3.28 2.88 0.70 1.79 0.69 2.73 2.64 1.59 3.94 1.59 2.49 May 3.99 3.13 2.21 5.07 6.46 6.74 4.16 3.44 8.18 1.39 4.45 1.60 1.69 2.15 3.68 3.89 June 6.28 3.54 1.82 5.82 4.50 2.90 3.28 1.85 3.13 3.57 2.18 1.58 2.95 2.43 3.21 3.27 July 3.39 2.80 0.40 4.29 3.79 2.49 3.62 2.60 1.72 3.65 5.55 2.43 3.07 2.07 2.14 2.93 August September 3.69 2.71 2.22 5.46 5.28 5.71 7.12 2.60 1.99 1.85 2.25 2.34 3.03 4.74 2.63 2.96 1.46 3.05 4.03 5.25 4.43 1.59 2.06 0.32 3.90 3.15 1.18 5.03 1.49 1.88 Total 22.77 15.66 12.10 30.16 28.46 25.55 22.65 13.25 17.13 15.05 20.31 11.77 17.36 16.82 15.13 3.57 2.79 18.94 2 GROWING DEGREE DAYS Tables 3 and 4 summarize the cumulative growing degree days (GDD) for 2010. Growing degree days base 50 for May through September, 2010, are in (Table 3) and growing degree days base 40 for May through September, 2010, are in (Table 4). The total GDD base 50 for 2010 was 2531 (Table 3), which is over 200 degree days higher than the 10-year average. The total GDD base 40 for 2010 was 3979 (Table 4). Table 3. Growing Degree Days* - Base 50°F. Cumulative Monthly Totals Year 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 10-Year Average May 317 319 330 245 195 283 358 205 247 352 285 June 808 903 762 662 826 765 926 700 700 857 791 July 1441 1646 1302 1200 1449 1444 1494 1298 1133 1561 1397 August September 2079 2214 1922 1639 2035 2016 2084 1816 1622 2231 2379 2613 2256 2060 2458 2271 2495 2152 1963 2531 1966 2318 Table 4. Growing Degree Days* - Base 40°F. Cumulative Monthly Totals May 532 639 447 519 610 June 1310 1503 1240 1264 1411 July 2298 2379 2147 2004 2424 August September 3180 3277 2973 2800 3402 3707 3966 3596 3420 3979 Year 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 10-Year Average *2001-2010 data from the weather station at MSU Montcalm Research Farm (Michigan Automated Weather Network System Entrican, MI.) 3734 549 1346 2250 3126 3 PREVIOUS CROPS, SOIL TESTS AND FERTILIZERS The general potato research area utilized in 2010 was rented from Steve Comden, directly to the West of the Montcalm Research Farm. This acreage was planted to a field corn crop in the spring of 2009 and harvested fall 2009 with crop residue disked into the soil. In the spring of 2010, the recommended rate of potash was applied in addition to 2 tons/A of dried chicken litter. These products were disked into the remaining corn residue. The chicken litter nutrient analysis was 4-3-2- 8%Ca with a carbon to nitrogen ratio of 6.9:1. The ground was deep chiseled, disked and direct planted to potatoes. The area was not fumigated with Vapam prior to potato planting, but Vydate was applied in-furrow at planting. Early potato vine senescence was not an issue in 2010. The soil test analysis for the general crop area was as follows: lbs/A P2O5 K2O Ca Mg pH 6.1 274 (137 ppm) 302 (151 ppm) 796 (398 ppm) 132 (66 ppm) The fertilizers used in the general plot area are as follows. (Variances in fertilizers used for specific research projects are included in the individual project reports.) Application Broadcast at plow down 0-0-21-10 At planting At cultivation At hilling Late side dress (late varieties) Rate 200 lbs/A 10 lbs/A 23 gpa 5 gpa 25 gpa 150 lbs/A 100 lbs/A 0-0-42-20 1 lbs B 71-0-0 6-20-0 77-0-0 69-0-0 46-0-0 10%B 28-0-0 10-34-0 28-0-0 46-0-0 46-0-0 Nutrients (N-P205-K20-Mg) Analysis Magnesium and Sulfur were applied on July 14 in the form of Magnesium Sulfate (with an analysis of 9.8% Mg and 12.9% S) for a total application of 10 lbs/A. The composite nutrient value resulted in 1 lb actual Mg and 1.3 lbs of S being applied per acre on the potato production area. Calcium and Nitrogen were applied July 20th and 26th in the form of liquid Calcium Nitrate (with an analysis of 30% Ca and 25% N) for a total application of 14 gpa. The composite nutrient value resulted in 46 lbs actual Ca and 39 lbs of N being applied per acre on the potato production area. 4 HERBICIDES AND PEST CONTROL A pre-emergence application of Lorox at 1.5 lbs/A and Dual at 1.33 pints/A was made in late May. A post-emergence application of Sencor at 1/3 lb/A and Matrix at 1 oz/A was made in mid-July. Admire and Vydate were applied in-furrow at planting at a rate of 8 fl oz/A and 2 quarts/A, respectively. Two foliar applications of Vydate were made on June 24th and July 9th at the rate of 1 quart /A. Fungicides used were; Bravo, Tanos and Manzate over 11 applications. Potato vines were desiccated with Reglone in early September at a rate of 2 pints/A. 5 2010 POTATO BREEDING AND GENETICS RESEARCH REPORT David S. Douches, J. Coombs, K. Zarka, G. Steere, M. Zuehlke, D. Zarka, K. Felcher and D. Kells Department of Crop and Soil Sciences Michigan State University East Lansing, MI 48824 Cooperators: Zsofia Szendrei, Willie Kirk, Jay Hao and Chris Long At Michigan State University, we are dedicated to developing improved potato INTRODUCTION varieties for the chip-processing and tablestock markets. The program is one of four integrated breeding programs in the North Central region supported through the Potato Special Grant. At MSU, we conduct a multi-disciplinary program for potato breeding and variety development that integrates traditional and biotechnological approaches. In Michigan, it requires that we primarily develop high yielding round white potatoes with excellent chip-processing from the field and/or storage. In addition, there is a need for table varieties (russet, red, yellow, and round white). We conduct variety trials of advanced selections and field experiments at MSU research locations (Montcalm Research Farm, Lake City Experiment Station, Muck Soils Research Farm, and MSU Soils Farm), we ship seed to other states and Canadian provinces for variety trials, and we cooperate with Chris Long on grower trials throughout Michigan. Through conventional crosses in the greenhouse, we develop new genetic combinations in the breeding program, and also screen and identify exotic germplasm that will enhance the varietal breeding efforts. With each cycle of crossing and selection we are seeing directed improvement towards improved varieties (e.g. combining chip-processing, scab resistance, and late blight resistance). In addition, our program has been utilizing genetic engineering as a tool to introduce new genes to improve varieties and advanced germplasm for traits such as solids, insect resistance, disease resistance and nutritional enhancement. We feel that these in-house capacities (both conventional and biotechnological) put us in a unique position to respond to and focus on the most promising directions for variety development and effectively integrate the breeding of improved chip-processing and tablestock potatoes. The addition of the SolCAP translational genomics project, funded through the USDA, will enhance our abilities to identify important traits and then breed them into elite germplasm. The SolCAP project has developed a new set of genetic markers (8,300) called SNPs that are located in the genes and we can use for linking to traits of interest such as dry matter content, low reducing sugars, bright skin, disease resistance, etc. The USPB is supporting national early generation trials called the National Coordinated Breeder Trial (NCBT) which will feed lines into the SFA trial. potato industry. Traits of importance include yield potential, disease resistance (scab, late blight, early die, and PVY), insect (Colorado potato beetle) resistance, chipping (out-of-the- The breeding goals at MSU are based upon current and future needs of the Michigan 6 program to make sound assessments of the breeding selections moving through the program. These include the establishment and expansion of the scab nursery, the development of the Muck Soils Research Farm for late blight testing (now moving to Clarksville), the incorporation of no-choice caged studies for Colorado potato beetle assessment, the Michigan Potato Industry Commission (MPIC)-funded construction of the B.F. (Burt) Cargill Demonstration Storage adjacent to the Montcalm Research Farm, new land at the Lake City Experiment Station along with a well for irrigation and expanded land at the Montcalm Research Farm and Lake City Experiment Station, the new plot harvester, the development of the grading line at the MSU campus facility, and expansion of the tissue culture operation so that small amounts certified seed of minitubers can be produced. field, storage, and extended cold storage) and cooking quality, bruise resistance, storability, along with shape, internal quality, and appearance. We are also developing potato tuber moth resistant lines as a component of our international research project. If these goals can be met, we will be able to reduce the grower’s reliance on chemical inputs such as insecticides, fungicides and sprout inhibitors, and improve overall agronomic performance with new potato varieties. Over the years, key infrastructure changes have been established for the breeding PROCEDURE I. Varietal Development The MSU breeding program has been operating for over 20 years and we feel that we have reached a point of “clarity and focus”. We have the genetic variation to combine tuber shape, skin type, scab resistance and low sugars, yield and storability as well as late blight resistance. We have increased our standards for what we consider a commercial selection because of this clarity and focus. In addition, we have also revised the selection scheme so that we have reduced a year from the early generation cycle. The MSU Breeding program continues to test MSU-bred lines in replicated trials (over 160 lines) and on grower farms (15 lines). We also enter 3-4 lines in the North Central regional trials, 2-3 lines in the SFA trials and send many of the advanced breeding lines to Ohio, Pennsylvania, Florida, California, North Dakota, Nebraska, Minnesota, North Carolina, Maine, Washington, Wisconsin, Ontario and Quebec Canada and various international sites for testing. The new NCBT in 2010 allowed us to test the over 40 MSU lines at 8 locations around the country. Through a cooperative effort of MPIC, commercial growers, seed growers, Chris Long, the MSU breeding program and the processors, we are working together to help move the best lines towards larger scale commercial testing and have chip-processing lines evaluated in the Commercial Demonstration Storage facility (500 cwt bins). At this time, we have many advanced selections that have chipping qualities along with scab or late blight resistance, bruise resistance, etc. with commercial potential. Five of these are in commercial seed production (MSJ126-9Y, MSH228-6, MSL292-A, MSR061-1 and MSQ070-1). At least 2 can store at temperatures below 50F and maintain low sugars until June. Each year the MSU breeding program will cross elite germplasm to generate and evaluate 50,000 new seedlings for adaptation to Michigan. In the subsequent years these selections are then advanced to 12-hill, 30-hill, 50-hill, and 100-hill plots, with increasing 7 Elite clones will be tested for at the Montcalm Research Farm for agronomic Currently, the breeding program has in tissue culture about 500 clones in the selection pressure for agronomic, quality and disease and/or insect resistance parameters. We now have in place field sites for early generation selection for late blight, scab and Colorado potato beetle resistant lines. Early generation evaluation of these key traits increases our effectiveness in identifying commercially valuable advanced selections. From this 3-year early generation evaluation and selection phase of the breeding program we generate over 100 MSU-bred advanced selections that are then to be tested and evaluated under more intensive replicated trials at the Montcalm Research Farm. We are also producing the FG1 and FG2 level seed of the most promising selections from the MSU breeding program for in-state grower-cooperator trials, out-of-state trials, North Central Regional trials, national USPB/SFA trials and MSU research farm trials. performance, marketable maturity, chip processing at harvest and in storage, resistance to pitted scab, potato early die and late blight. We place these advanced selections into tissue culture and initiate virus eradication procedures so that virus-free tissue culture plantlets or tuber sources can be made available to the industry. We are moving towards using a commercial NFT mini-tuber production system to produce mini-tubers of our advanced selections. MSU bank and 80 new candidates that are in process for transfer to tissue culture. We want to continue to work closely with the commercial growers and seed industry to test and provide seed for more intensive evaluation. Through this linkage we hope to identify the breeding selections that have merit to achieve varietal status in Michigan. There is a need to find a russet table potato that will be profitable and produce quality russets for the eastern market. Currently, the three most desirable potatoes for production and type in Michigan are GoldRush, Russet Norkotah and Silverton Russet. The latter two potatoes suffer as symptomless carriers of PVY. Norkotah also has a weak vine and susceptibility to potato early die. We need a PVY resistant or PVY expressing Silverton Russet potato. We are continuing to make more russet crosses and selections in the breeding program to support this new russet market. Evaluation of Advanced Selections for Extended Storage we are positioned to evaluate advanced selections from the breeding program for chip- processing over the whole extended storage season (October-June). Tuber samples of our elite chip-processing selections are placed in the demonstration storage facility in October and are sampled monthly to determine their ability to chip-process from colder (42-48°F) and/or 50°F storage. In addition, Chris Long evaluates the more advanced selections in the 10 cwt. box bins and manages the 500 cwt. storage bins which may have MSU-developed lines. II. Germplasm Enhancement "diploid" (2x = 24 chromosomes) breeding program in an effort to simplify the genetic With the Demonstration Storage facility adjacent to the Montcalm Research Farm, To supplement the genetic base of the varietal breeding program, we have a 8 system in potato (which normally has 48 chromosomes) and exploit more efficient selection of desirable traits. This added approach to breeding represents a large source of valuable germplasm, which can broaden the genetic base of the cultivated potato. The diploid breeding program germplasm base at MSU is a synthesis of seven species: S. tuberosum (adaptation, tuber appearance), S. raphanifolium (cold chipping), S. phureja (cold-chipping, specific gravity, PVY resistance, self-compatability), S. tarijense and S. berthaultii (tuber appearance, insect resistance, late blight resistance, verticillium wilt resistance), S. microdontum (late blight resistance) and S. chacoense (specific gravity, low sugars, dormancy and leptine-based insect resistance). Even though these potatoes have only half the chromosomes of the varieties in the U.S., we can cross these potatoes to transfer the desirable genes by conventional crossing methods via 2n pollen. III. Integration of Genetic Engineering with Potato Breeding Through transgenic approaches we have the opportunity to introduce new genes into our cultivated germplasm that otherwise would not be exploited. It has been used in potato as a tool to improve commercially acceptable cultivars for specific traits. Our laboratory has now 16 years experience in Agrobacterium-mediated transformation to introduce genes into important potato cultivars and advanced breeding lines. We are presently using genes in vector constructs that confer resistance to Colorado potato beetle and potato tuber moth (Bt- cry3A and Bt-cry1Ia1), late blight resistance via the RB gene (from the wild potato species S. bulbocastanum), drought resistance (CBF1), PVY, late blight resistance from S. microdontum, and lower reducing sugars with acid invertase gene silencing. RESULTS AND DISCUSSION I. Varietal Development Breeding germplasm and advanced seedlings that are improved for cold chipping, and resistance to scab, late blight, and Colorado potato beetle. For the 2010 field season, progeny from over 500 crosses were planted and evaluated. Of those, the majority were crosses to select for round whites (chip-processing and tablestock), with the remainder to select for yellow flesh, long/russet types, red-skin, and novelty market classes During the 2010 harvest, over 1,200 selections were made from the 50,000 seedlings produced. All potential chip-processing selections will be tested in January and April 2011 directly out of 45°F (7.2°C) and 50°F (10°C) storages. Atlantic, Pike (50°F chipper) and Snowden (45°F chipper) are chip- processed as check cultivars. Selections have been identified at each stage of the selection cycle that have desirable agronomic characteristics and chip-processing potential. At the 12- hill and 30-hill evaluation state, about 300 and 60 selections were made, respectively. Selection in the early generation stages has been enhanced by the incorporation of the Colorado potato beetle, scab and late blight evaluations of the early generation material. Chip-Processing pedigree. Our promising chip-processing lines are MSJ147-1, MSH228-6 (moderate scab resistance), MSJ126-9Y (scab resistant), MSL007-B (scab resistance), MSR169-8Y (scab resistant), MSQ086-3, (late blight resistant), MSL292-A, MSR061-1 (scab and PVY Over 80% of the single hill selections have a chip-processing parent in their The MSU potato breeding and genetics program is actively producing new 9 Efforts have been made to identify lines with good appearance, low internal defects, resistant) and MSQ070-1 (scab and late blight resistant). Other new promising lines include MSP270-1 (scab resistant), MSP516-A (scab and late blight resistant), MSR036- 5 (scab and late blight resistant), MSR127-2 (scab resistant) and MSQ279-1 (scab resistant). Tablestock good cooking quality, high marketable yield and resistance to scab, late blight and PVY. Our current tablestock development goals now are to continue to improve the frequency of scab resistant lines, incorporate resistance to late blight along with marketable maturity and excellent tuber quality, and select more russet and yellow-fleshed lines. We have also been spinning off some pigmented skin and tuber flesh lines that may fit some specialty markets. We are planning to release four lines for the specialty market (MSN215-2P, MSR226-1RR, MSQ425-4PY and Midnight). From our breeding efforts we have identified mostly round white lines, but we also have a number of yellow-fleshed and red-skinned lines, as well as some purple skin selections that carry many of the characteristics mentioned above. We are also selecting for a dual-purpose russet, round white, red-skin, and improved Yukon Gold- type yellow-fleshed potatoes. Some of the tablestock lines were tested in on-farm trials in 2010, while others were tested under replicated conditions at the Montcalm Research Farm. Promising tablestock lines include MSL211-3, MSQ440-2, MSM182-1 and MSL268-D and MSQ176-5. We have a number of tablestock selections with late blight resistance (MSQ176-5, MSM182-1, and MSL268-D). MSL211-3 has late blight and moderate scab resistance with a bright skin. We are using these russets as parents in the breeding program to combine the late blight and scab resistance. Some newer lines with promise include the high yielding round white line MSQ279-1 (scab resistant), MSQ440-2 (scab resistant) and MSN230-6RY (scab and late blight resistant). MSM288-2Y is a bright yellow flesh selection similar in type to Yukon Gold. MSS544-1R is a new scab resistant red skinned table potato. Some new pigmented lines are MSS576-05SPL (red splash) and Michigan Red and Purple Splash. MSQ558-2RR and MSR226-1RR are red fleshed chippers and Midnight is a purple-fleshed chipper. Early harvest breeding material screen learn about the potential to replace Atlantic as an early harvest variety. We harvested the plots at 90 days and observed the yield, tuber size and tuber shape/ appearance. In addition, we measured specific gravity and made chips out of the field. From this trial of 191 lines, we were able to identify some promising early breeding lines for the out-of-the-field chipping and tablestock use. Table 1 (next page) summarizes these results of the lines with the highest merit ratings. Some of these lines are also characterized to have some scab resistance and late blight resistance along with the desirable chipping traits. We will continue to test many of these lines and other selections in 2011. Some of these lines are MSQ035-3, MSQ086-3 and MSR127-2. We also identified some desirable early tablestock lines among this material tested. These lines are MSL211-3, MSM182-1, MSM288-3Y, MSQ440-2 and MSS576-05SPL. In 2010, we had a second early harvest observation trial of our breeding lines to 10 Table 1 Early Observation Trial: Most promising lines.    Line  Atlantic  FL1879  Kalkaska  (J036‐A)  Snowden  Michigan  Purple  MSL211‐3  MSM182‐1  MSM288‐2Y  MSN215‐2P  MSNDU045‐1  MSQ035‐3  MSQ086‐3  MSQ341‐BY  MSQ425‐4Y  MSQ440‐2  MSQ461‐2PP  MSR089‐9Y  MSR127‐2  MSR214‐2P  MSR219‐2R  MSR241‐4RY  MSS258‐1  MSS576‐05SPL  MSU161‐1  MSU200‐5PP  MSU278‐1Y  Reba  1=Good;  4=Bad  Merit  2  2  2.5  2  1.5  1  2  2  1.5  2  2  2  2  2  1.5  2  2  2  2  2  2  2  1  2  2  1.5  2  Total  Weight  (kg)  9.88  6.26  7.62  8.46  9.10  11.14  6.78  9.94  6.97  7.39  9.44  9.09  7.11  9.66  8.78  9.26  7.79  8.04  5.59  5.68  5.93  6.28  9.74  7.09  4.16  8.01  8.15  Specific  8/16/10        Gravity  1.088  1.068  OTF  Chip  2.0  1.0  MAT  2.0  2.5  Female  Male  1.073  1.079  1.066  1.070  1.059  1.067  1.064  1.057  1.075  1.076  1.071  1.069  1.060  1.074  1.080  1.077  1.083  1.055  1.073  1.061  1.066  1.068  1.057  1.060  1.067  2.0  1.5  ‐  ‐  ‐  1.5  ‐  1.5  1.0  1.0  1.0  ‐  ‐  1.5  1.0  1.5  ‐  ‐  ‐  1.5  ‐  2.5  1.5  2.5   ‐  2.5  2.5  1.0  2.0  2.5  2.5  2.0  2.0  3.0  3.0  2.5  2.5  2.5  3.0  3.0  3.0  3.0  2.5  2.5  2.5  2.5  3.0  3.0  3.0  2.5  ‐  MSG301‐9  Stirling  MSG145‐1   MI Purple  ‐  MSG227‐2  Onaway  MSJ126‐9Y  MSG147‐3P  MSK214‐1R  NY120  MSJ319‐1  MSJ167‐1  ND5084‐3R  NDTX4271‐5R  PoorpG9‐3  MSH098‐2  MSI005‐20Y  MSM182‐1  MSN111‐4PP  Torridon  ‐  ‐  J. Lee  NY121  MSA097‐1Y  Norland  ‐  Missaukee  Missaukee  NY120  MSJ319‐1  Missaukee  POROOPG2‐16  OP  MSG227‐2  MSJ317‐1  Stirling  MN96013‐RY  MSH228‐6  MSL211‐3  MSL211‐3  NDTX4271‐5R  MSL211‐3  ‐  11 Scab: Disease screening for scab has been an on-going process since 1988. In 2010 We have been conducting trials in the NFT system to identify the conditions and Disease and Insect Resistance Breeding we added an on-farm trial and a new site at the Montcalm Research Farm for scab evaluation. Some of results are summarized in Table 2. The susceptible checks of Snowden and Atlantic were highly infected with pitted scab. Interestingly, Onaway had pitted lesion in the on-farm field. Promising resistant selections were CO95051-7W, MSJ126-7Y, MSH228-6, MSL007-B, MSR061-1, MSR169-8Y, MSP270-1, MSQ279-1 and MSQ440-2. The high level of scab infection at the on-farm site with a history of scab infection and MRF helped with our assessment of resistance and susceptibility. Results from the 2010 MSU scab nursery were not used because the level infection was too low. We also had to drop our scab inoculation study to examine factors to increase scab in the field because of low infection on the tubers! The MRF scab site was used for assessing scab susceptibility in our advanced breeding lines and early generation material. Of the advanced breeding lines 60 of 160 lines evaluated had a scab rating of 1.0 or less (better than Pike). The single observation early generation assessment for scab resistance among our breeding material was very good. In 2010, 97 of 227 early generation selections showed strong scab resistance (rating of 1.0 or better). Based upon this data, scab resistance is increasing in the breeding program. These data were also incorporated into the early generation selection evaluation process at Lake City. We are seeing that this expanded effort is leading to more scab resistant lines advancing through the breeding program. inoculation method that optimizes tuberization and infection of a scab susceptible cultivar. Previous trials were conducted at the MSU Crops Barn and resulted in poor tuberization and thrip infestations. For the spring, 2010 trial the NFT system was moved to our greenhouse in order to better control the intensity of light, the day-length and insect pressure and thereby improve tuberization. In general, each plant produced 1 mini- tuber with some plants producing two to three mini-tubers. We also tried using plastic cups for this trial rather than peat pots. This was done so that we could monitor stolon development and be better able to time the application of the inoculum. The plastic cups did allow us to see the stolons developing but may have contributed to the poor vigor of the plants and an unexpected number of rotten tubers. plants yielded high numbers of infected tubers (92 to 100% infection rates). However, based on the scab index rating, there was no difference in the amount of disease between tubers subjected to inoculated vermiculite (2.4 scab index rating) and those that were drenched in addition to the inoculated vermiculite (2.5 scab index rating). In Liberator, 22% of the control tubers were infected (small patches of raised lesions), 92% of the tubers in inoculated vermiculite were infected and 72% of the tubers that were drenched were infected. Based on scab index ratings, there was no difference between tubers in inoculated vermiculite (1.6 scab index rating) and those that were drenched (2.4 scab index rating). Based on the results of this study we will continue to conduct NFT trials in the greenhouse under the same growing conditions. However, we will revert to using peat pots rather than plastic cups. Not only were the plastic cups difficult to prepare, they In Atlantic, as expected, the controls were basically uninfected and the inoculated 12 retained more water and impeded the solution flow through the troughs allowing nutrient solution to stand in the troughs. This likely contributed to poor plant vigor and tuber rot. As there was no difference in the amount of disease between the 2 inoculation methods, we will use inoculated vermiculite in subsequent trials but will drench the plants once (3 weeks after the vermiculite is added to the pots) to ensure high concentrations of inoculum. We feel as though we have optimized the system and are ready to conduct replicated trials on multiple breeding lines. The NFT study is supported through Project GREEEN. Table 2. Streptomyces Scab Trial Results from three trial locations. Location  On Farm  Montcalm  Campus  Late Blight: Our specific objective was to breed improved cultivars for the industry that have foliar and tuber resistance to late blight using a combination of conventional breeding, marker-assisted strategies and transgenic approaches. Through conventional breeding approaches, the MSU potato breeding and genetics program has developed a    Line   Chip‐processing Lines  Atlantic   Snowden   Beacon Chipper   Kalkaska   Pike   CO95051‐7W   MSJ126‐9Y   MSH228‐6   MSL007‐B   MSJ147‐1   MSL292‐A   MSR061‐1   MSQ070‐1   MSP270‐1   MSQ035‐3   MSR169‐8Y   MSQ279‐1   Mean  Tablestock Lines  Onaway   MSL211‐3   MSQ176‐5   MSN215‐2P   MSQ440‐2   Mean  3.8  3.0  3.0  1.8  1.5  1.0  1.0  2.0  2.0  1.3  3.5  1.6  1.5  1.0  1.8  2.0  1.3  1.9  2.3  2.3  3.5  1.0  1.3  2.1     2.9  2.9  2.0  1.5  1.1  1.5  1.0  1.0  1.0  1.3  2.5  1.3  1.3  1.0  1.0  1.0  1.3  1.5     2.0  1.5  1.0  0.5  0.9  1.0  1.0  1.0  1.0  1.0  1.5  1.0  0.5  0.5  1.0  0.5  1.0  1.0     2.1  2.2  3.0  1.0  1.8  2.0     0.8  1.7  1.5  0.0  0.5  0.9  13 series of late blight resistant advanced breeding lines and cultivars that have diverse sources of resistance to late blight. In 2010 we conducted late blight trials at the Muck Soils Research Farm. We inoculated with the US8 genotype, but the foliar reaction to the Phytophthora infestans was different from all previous years. In some cases lines that were classified as resistant were susceptible. On the other hand, some of the lines with moderate resistance in previous years were highly resistant in 2010. This difference in late blight reaction could be attributed to the US22 genotype that was found in fields in Michigan. In the 2010 trials, 39 of 139 early generation lines were resistant to late blight comprised of 15 sources of late blight resistance. Of the 157 advanced breeding lines and varieties tested, 37 were resistant. Fourteen sources of resistance can be traced in the pedigrees of these resistant lines. This data infers that we have a broad genetic base to combine resistance genes and also should be able to respond to changes in the pathogen. We used marker-assisted selection strategies to combine a resistance QTL through conventional breeding. One approach to breeding for foliar resistance to late blight is to use interploidy (4x-2x) crosses to introgress the late blight resistance from Solanum microdontum. Eight of 10 4x-2x selections were resistant combining resistance from S. microdontum and varieties Stirling and Jacqueline Lee. At the diploid level 18 of 30 2x selections were resistant that combine resistance genes from S. berthaualtii and S. microdontum. We are hoping that with a combination of conventional crossing and transgenic approaches we can create cultivars that can be commercialized by the North American potato industry that have a stronger resistance. Agrobacterium-mediated transformation has been used to introgress the RB gene, cloned from Solanum bulbocastanum, into susceptible cultivars. We have crossed these lines with the conventionally-bred resistant lines and applied the same marker-assisted selection strategies to characterize the lines that may be combining late blight resistance R-genes. Twelve of 20 4x selections express the RB gene for resistance to late blight in the 2010 trials. In addition, we compared three crosses for their late blight reaction when segregating for the RB gene. Spunta-RB (a late blight resistant transgenic line) was crossed to susceptible (MSJ126-9Y), moderately resistant (MSN105-1) and resistant (M244-1) line. Progeny were determined to be carrying the RB gene (RB+) or not (RB-). Foliar late blight reaction was measured on each individual in the cross over three replications. The crosses segregating for late blight resistance genes gave us valuable information. The data is summarized in the three figures. In all three crosses the majority of the RB progeny were resistant to late blight. The frequency of progeny with late blight resistance increased in relation to the late blight resistance of the parent crossed to Spunta-RB. The cross with only one resistant gene had a few progeny with late blight resistance. The lines with at least two resistant genes segregating had a much higher frequency of progeny with a high level of resistance to late blight. For example, only 6 of the 26 progeny in the Spunta-RB x MSQ244-1 cross were classified as susceptible. This study supports our breeding efforts to combine resistance genes to late blight to achieve more durable resistance. This is a GREEN-funded project. 14 y c n e u q e r F y c n e u q e r F y c n e u q e r F 20 15 10 5 0 25 20 15 10 5 0 12 10 8 6 4 2 0 RB X Late Blight Susceptible (V528 (RB Spunta X MSJ126‐9Y)) 5 10 15 20 25 30 35 40 45 50 RAUDPC (x100) RB X Moderate Late Blight Resistance (V532 (RB Spunta X MSN105‐1)) 5 10 15 20 25 30 35 40 45 50 RAUDPC (x100) RB X Late Blight Resistant (V533 (RB Spunta X MSQ244‐1)) 5 10 15 20 25 30 35 40 45 50 RAUDPC (x100) RB‐ RB+ RB‐ RB+ RB‐ RB+ 15 Colorado potato beetle: With support from GREEEN, we conducted our Colorado potato beetle resistance screening. In 2010 we focused on screening our selections with detached leaf bioassays (no-choice) and screening new genetic material for resistance. The new species were screened through detached leaf bioassays and screened field cages. Some breeding lines were at least moderately resistant or showed reduced susceptibility to Colorado potato beetle in the detached leaf bioassays. In the field cages, the adults that were added to the cages clipped the leaves on some of the lines. We have seen this behavior previously when we have strong resistance but the beetles have no choice. We need to repeat the testing of some of these lines in 2011 and study larval behavior. Some of these lines are beginning to enter the preliminary trials in the breeding program and are being used as parents for further breeding. We have been using the moderately resistant breeding lines for crossing and we have been selecting seedling with improved tuber appearance. Combining host plant resistance to insects in a commercially acceptable line is a great challenge. Russet Table Varieties for Michigan Our breeding strategy has been to make selected crosses that have a high probability of selecting Norkotah types. We grew out large progenies over the past two years to further increase the probability of finding desirable selections. We will continue to use Silverton, Russet Norkotah, MSE192-8RUS, A95109-1RUS, etc. as parents. Single hill selections were made in 2009 and 2010. These early generation selections will be further evaluated in 2011 as well as a new set of crosses will be evaluated at Lake City. Sugar Profile Analysis of Early Generation Selections for Extended Storage: Chip- processing Results From the MPIC Demonstration Commercial Storage (October 2009 - June 2010) evaluations each year on potato lines from the MSU breeding program and from other states. For 11 years we have been conducting a long-term storage study to evaluate advanced breeding lines with chip-processing potential in the Dr. B. F. (Burt) Cargill Potato Demonstration Storage facility directly adjacent to the MSU Montcalm Research Farm to identify extended storage chippers. We evaluated advanced selections from the MSU breeding program for chip-processing over the whole extended storage season (October-June). Tuber samples of our elite chip-processing selections were placed in the demonstration storage facility in October and were sampled 9 times to determine their ability to chip-process from storage. The MSU Potato Breeding Program has been conducting chip-processing In October 2009, tuber samples from 19 MSU lines from the Montcalm Research Farm and Lake City Experiment Station trials were placed in the bins along with four check varieties. The first samples were chip-processed in October and then 8 more times until June 2010. Samples were evaluated for chip-processing color and defects. Table 3 summarizes the chip-processing color and scab rating of 19 lines and four check varieties (Atlantic, FL1879, Pike and Snowden) over the 7-month storage season. From November a number of lines had poor chip color that was attributed to the cold harvest conditions of some of the lines (Kalkaska, MSQ035-3, MSR102-3, MSR159-02, 16 MSR058-1 and MSQ131-A). Other lines chip processed well from the storage until April. The lines that chip processed well until May were MSP459-5, MSP270-1 and MSR061-1.The lines that chip processed exceptionally well until June were MSH228-6, MSJ126-9Y, MSL292-A, and Pike. These lines are highlighted in the table. We are that some of the lines with good chip quality also have scab resistance and/or late blight resistance. Resistance Table 3: 2009-2010 Demonstration Storage Chip Results of Elite MSU Breeding Lines 2010 Scab 11/10/09 12/9/09 1/5/10 2/1/10 3/1/10 4/7/10 5/10/10 56 F 55 F SFA Chip Score Rating Scale 1-5 55 F 55 F 55 F 55 F 6/2/10 54 F 54 F Line 1.5 1.5 1.0 2.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 2.0 1.0 2.0 1.0 2.5 2.0 1.5 1.0 ND ND 1.5 1.5 1.0 1.0 2.0 1.5 1.5 1.5 1.5 ND 1.0 1.0 1.0 2.0 1.0 2.0 1.5 2.5 2.0 ND 1.5 2.0 1.0 1.5 1.5 1.0 1.0 2.0 1.5 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.5 1.0 2.0 1.5 2.5 2.0 1.0 1.5 ND 1.0 1.0 1.0 1.5 1.5 1.5 1.5 1.5 1.0 1.0 2.0 1.5 1.0 1.0 2.5 1.0 2.0 1.5 2.5 2.0 1.0 1.0 2.5 1.5 1.0 1.5 2.5 1.0 2.0 1.5 1.0 1.5 1.5 ND 2 1.0 1.0 2.0 1.5 ND 1.5 2.5 2.0 1.5 1.5 2.0 1.0 2.5 ND 2.5 1.5 2.5 1.0 1.0 2.0 2.5 1.0 2.5 1.0 1.5 1.5 2.0 ND 1.5 3.0 1.5 1.5 ND 2.0 2.0 3.0 ND 2.5 2 2.5 1.5 1.5 2 3 1.5 3.5 ND 2 2 2.0 ND 2 3 2.5 ND 2 2.5 1.5 3 ScabMR ScabR ScabR ScabR ScabMR ScabR Atlantic Beacon Chipper ScabMR FL1879 Kalkaska MSH228-6 MSJ126-9Y MSJ147-1 MSK061-4 MSL292-A MSN148-A MSP459-5 MSP270-1 MSQ035-3 MSQ070-1 MSQ131-A MSQ461-2PP MSR036-5 MSR058-1 MSR061-1 MSR102-3 MSR159-02 Pike Snowden ScabR ScabR, LBR ScabR, LBR LBR ScabR, LBR ScabMR, MRLB ScabR, LBR, PVYR LBR ScabR MRScab ScabR 2.9 2.0 3.5 1.5 1.0 1.0 1.3 - 2.5 1.5 3.0 1.0 1.0 1.3 - 2.0 1.0 1.5 1.3 1.0 2.0 1.1 2.9 2.0 1.0 1.5 2.5 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 3.0 1.0 3.0 1.0 3.5 3.0 1.0 2.5 3.0 1.0 2.5 Early generation sugar profiling was also conducted on a series of MSU advanced breeding lines. These glucose and sucrose sugar profiles are presented in Figures 1 and 2. The results confirm the good storage potential of MSJ126-9Y, MSH228-6 and MSL292-A. MSJ147-1 has stored longer in 2010 than 2009. The long storability advantage has been compromised by the average or below average yield in commercial fields. Of the newer advanced breeding lines tested MSQ070-1 and MSR061-1 showed promising sugar profiles. Both lines exhibit scab resistance. During the 2009-10 storage season the MPIC/MSU conducted studies to examine acrylamide content in potato chips made from Snowden and three MSU advanced 17 breeding lines stored in the MPIC commercial storage bins. Samples were collected every two weeks starting in December and continued for a total of 6 dates. The tuber samples were sent to MSU, TechMark and four commercial processors for chip processing. The commercial processors processed the potatoes as continuous and kettle chips. The chips were sent to MSU for acrylamide sampling. The ground chip samples were sent to the University of Wisconsin for acrylamide analysis. From this study we learned that variety, processor and process type (continuous vs. kettle) influences acrylamide levels in the chips. The oil temperature and dwell time were also important. Glucose levels were not as important within the range of values we observed (0.001- 0.005%). Kettle chips, fried at lower temperatures, had lower acrylamide levels. One variety had an average of 230 ppb acrylamide in the kettle chips. A second study looked at more varieties over the storage season, but the chip samples evaluated for acrylamide were processed at TechMark. Variety differences were observed. 2009 was an unusually cool growing season. Many potatoes went into storage as immature tubers. This condition may have had an influence on the reducing sugar content in the tubers. 2010 has been a warm growing season and the tubers matured much faster. Table 4. Overall Analysis of Variance of main effects means for acrylamide for variety, process-type, and processor effects. Overall ANOVA of Main Effects for Acrylamide        Acrylamide        Variety Effect  Variety 2  Variety 1  Variety 4  Variety 3  Process‐type Effect  Continuous  Test Batch  Kettle  Processor Effect  Processor 2  Processor 5  Processor 6  Processor 1  Processor 4  Processor 3              C              A  A           A  A        A  A  A                 B  B              B           B  B  B  B              (ppb)     708  644  552  401     733  635  395     780  679  594  489  469  463     *Effects were analyzed separately. Effects with the  same letter are not significantly different at  α=0.05.  18 We propose to conduct a follow up study to the 2009 season so that we can have a better understanding of the season effect on acrylamide formation in the chips. We will examine three potato lines: Snowden, MSJ147-1 and NY139. We will sample the tubers every four weeks during the storage season until the tubers reach physiological maturity. The tuber samples will be processed by TechMark and one commercial processor. The chips will be sent to MSU for processing and the University of Wisconsin will run the acrylamide analysis. Snowden and MSJ147-1 are chosen because these two lines were the best lines for maintaining low acrylamide levels in the 2009-10 storage season. We need to make direct comparisons to that year. We will also include NY139 because of Michigan’s commercial interest in this line. 19 National Coordinated Breeder Trial (NCBT) 2010 was the first year of the NCBT. The purpose of the trial is to evaluate early generation breeding lines from the US public breeding programs for their use in chip- processing. The NCBT has 8 sites (North: NY, MI, WI, ND and South: NC, FL, TX, CA) in addition to a scab trial in MN. A total of 220 lines were tested as 15-hill single observation plots. The lines were evaluated for tuber type and appearance, yield, specific gravity, chip color and chip defects. The data is being prepared to be posted on a website database for the public to use. The lines with the best performance will be retested in 2011 and new early generation lines will be added. Table 5 summarizes the data of the location merit rating. Three checks (Atlantic, Snowden and Megachip) and 68 lines are included in the table. Lines that received a high merit rating in at least two locations are included in the table. Those lines that had a high rating in at least two southern locations are highlighted in yellow. Those lines that had a high rating in at least two northern locations are highlighted in green. Those lines that had a high rating in at least two northern and southern locations each are highlighted in blue. MSU had 19 of the 68 lines in the table. Moreover, the MSU lines were more scab resistant than the lines from the programs. Some of the promising lines are MSL007-B, MSR169-8Y, MSR058-1, MSR127-2, MSR148-4 andMSS165-2Y. Beacon Chipper also showed merit in the northern sites. 20 Table 5. National Coordinated Breeder Trial (NCBT) Overall merit ranking summary. ( ) g y Location ‐ North 2 Scab ND WI MN MR 1 1 SUSC MR R 2 36 24 25 13 2.0 1.8 1.9 88 98 186 Location ‐ South Merit CA 2 FL 2 2 1 2 1 2 2 1 1 1 1 2 1 2 1 2 1 1 2 1 1 2 2 2 1 2 1 2 2 2 1 2 2 1 2 1 1 1 2 1 NC TX 3 3 2 1 3 3 2 2 3 3 1 1 2 3 1 3 2 1 3 1 1 4 4 1 4 4 3.5 4 1 2 1 2 2 4 3 3 2 2 1 4 1 2 4 3 2 4 21 20 26 3 21 NY 2 2 1 2 1 2 2 1 2 2 1 2 2 2 2 2 2 2 2 2 2 2 2 2 MI 2 1 2 1 1 1 1 2 1 2 2 1 2 2 1 1 1 2 2 2 2 2 2 2 2 1 2 2 2 1 1 2 2 2 2 2 Line MSL007‐B CO02321‐4W MSR058‐1 NYE106‐4 NYE50‐8 Atlantic MSR169‐8Y MSS165‐2Y MSK409‐1 MSR127‐2 AC01151‐5W Beacon Chipper MSM246‐B ND8331Cb‐3 NYG20‐58 NYG20‐63 NYG86‐1 NYG87‐3 Snowden A‐32 B2721‐78 BNC202‐7 CO02024‐9W MSL292‐A MSR148‐4 NYG20‐30 B2721‐101 B2721‐13 MSR128‐4Y NYF57‐3 NYG20‐31 NYG20‐41 NYG20‐55 NYG20‐56 NYG89‐2 W5955‐1 W8539‐2 W8615‐5 B2721‐63 B2721‐64 B2721‐73 MSK061‐4 MSP459‐5 MSQ130‐4 NYD40‐50 NYG20‐11 NYG20‐13 W8603‐1 A03471‐7C AC03433‐1W AF4240‐3 AF4254‐2 AF4307‐1 AF4363‐2 B1992‐106 B2721‐121 B2721‐18 B2721‐40 B2721‐67 B2721‐93 Boulder CO00270‐7W MegaChip MSQ035‐3 MSQ089‐1 MSR036‐5 MSS026‐2Y ND7799c‐1 NDMN07‐B322BG1 W2324‐1 W2717‐5 71 Female MSA105‐1 A91790‐13 Megachip NY128 V101‐9 Pike MSM188‐1 MSC148‐A MSJ167‐1 A91790‐13 UEC MSE274‐A ANDOVER ANDOVER NY138 NY139 Superior BC0894‐2W Snowden MSI152‐A ANDOVER NY115 Male MSG227‐2 S440 MSJ319‐1 MARCY NY115 Program MSU‐MI CSU‐CO MSU‐MI Cornell‐NY Cornell‐NY Check MSU‐MI MSJ126‐9Y MSU‐MI MSL159‐AY MSU‐MI Liberator MSG227‐2 MSU‐MI NDTX4930‐5W CSU‐CO MSU‐MI MSU‐MI NDSU‐ND Cornell‐NY Cornell‐NY Cornell‐NY Cornell‐NY Check UoWI‐WI USDA‐MD USDA‐MD CSU‐CO A91790‐13 MSH098‐2 MSU‐MI Dakota Pearl MSU‐MI NY115 NY119 NY120 C956‐1 MARCY Snowden MSJ167‐1 WHITE PEARL ANDOVER ANDOVER ANDOVER ANDOVER NY139 MSJ126‐9Y NY115 NY115 NY116 NY117 NY118 C956‐1 Cornell‐NY USDA‐MD USDA‐MD MSU‐MI Cornell‐NY Cornell‐NY Cornell‐NY Cornell‐NY Cornell‐NY Cornell‐NY UoWI‐WI UoWI‐WI UoWI‐WI USDA‐MD USDA‐MD USDA‐MD MSC148‐A Marcy Boulder NY121 ANDOVER ANDOVER Dakota Diamond A98399‐1C A94322‐8C SC9512‐4 A8469‐5 A97070‐51LB A91790‐13 COA96141‐4 AF290‐5 AF290‐5 A95162‐1 W2309‐7 Dakota Pearl MSU‐MI NY121 MSU‐MI MSU‐MI MSJ456‐4Y Cornell‐NY NY115 Cornell‐NY NY114 Cornell‐NY NY115 UoWI‐WI USDA‐ID CSU‐CO UoM‐ME UoM‐ME UoM‐ME UoM‐ME USDA‐MD USDA‐MD USDA‐MD USDA‐MD USDA‐MD USDA‐MD MSU‐MI CSU‐CO UoWI‐WI MSU‐MI MSU‐MI MSU‐MI MSU‐MI NDSU‐ND UoM‐MN UoWI‐WI UoWI‐WI Missaukee Missaukee Liberator MSJ126‐9Y NY88 A91790‐13 MS702‐80 CO95051‐7W MSG227‐2 A91790‐13 MSL766‐1 SJ‐Y7 69 lines with 2 or more merit scores 2 checks: Snowden and Atlantic select for both select for north select for south one select in N and S 7 22 18 23 Merit South North Overall Mean Mean Mean 1.8 1.6 2.0 1.6 2.2 1.6 2.0 1.8 2.3 1.8 1.7 2.7 1.3 1.7 1.7 1.3 2.3 2.0 1.3 2.8 2.7 1.7 2.0 1.7 1.3 2.3 2.0 2.0 2.0 2.0 2.0 2.0 1.5 2.0 2.0 2.3 2.0 2.5 1.0 1.5 1.5 2.0 1.5 3.5 2.0 1.5 3.0 1.5 1.5 1.5 2.0 2.0 1.5 3.0 1.0 1.5 2.0 1.5 2.0 3.0 2.5 1.5 1.5 2.0 1.5 2.0 1.5 2.0 3.0 1.5 2.5 2.0 2.0 2.5 1.5 3.0 2.0 2.3 1.5 2.3 2.0 1.0 4.0 1.0 1.0 1.0 1.0 2.0 2.0 2.0 3.3 3.0 1.5 2.0 2.0 1.5 2.5 ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ 1.0 1.5 1.5 2.0 1.5 3.5 2.0 1.5 3.0 1.5 1.0 1.0 2.0 2.0 1.0 4.0 1.0 1.0 2.0 1.0 2.0 4.0 3.0 1.0 2.0 3.0 1.0 2.0 1.0 2.0 4.0 1.0 3.0 1.8 1.3 1.7 1.7 1.7 1.0 1.5 2.0 2.0 1.7 2.0 2.0 1.5 2.0 2.0 1.5 2.5 2.0 1.0 2.0 2.0 2.0 2.0 1.0 1.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 1.5 2.0 2.0 2.3 2.0 2.5 ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ 2.0 2.0 2.0 2.0 2.0 2.0 1.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 1.0 1.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 South Count North Overall Count Count 2 2 2 2 2 3 3 2 3 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 0 0 0 0 0 0 0 0 0 0 0 0 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 3 3 3 3 2 2 2 1 3 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 6 5 5 5 5 5 5 4 4 4 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 2 2 2 2 2 1 2 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2.5 2 2 SUSC SUSC R R MR R SUSC SUSC SUSC SUSC SUSC SUSC SUSC MR SUSC SUSC SUSC ND SUSC susc SUSC SUSC SUSC SUSC SUSC SUSC SUSC SUSC MR SUSC SUSC SUSC MR MR SUSC SUSC SUSC MR SUSC SUSC ND SUSC SUSC SUSC SUSC SUSC SUSC SUSC SUSC SUSC ND SUSC SUSC SUSC MR SUSC SUSC SUSC SUSC MR SUSC R SUSC SUSC ND SUSC R 21 Variety Release We released MSJ461-1 as Missaukee (late blight, golden nematode and verticillium wilt resistant round white) in 2010. We are continuing to promote the seed production and testing of Beacon Chipper, a 2005 release. In addition, we are also continuing to promote Michigan Purple, Jacqueline Lee for the tablestock specialty markets. Boulder is being commercially grown in Quebec and they now have interest in Kalkaska based upon 2 years of trials. Lastly, commercial seed of MSH228-6 and MSJ126-9Y are being produced and we will continue to seek commercial testing of these lines. MSL292-A (long-term chipper), MSR061-1 (scab, PVY and late blight resistant chipper), MSL007-B (scab resistant chipper), MSQ086-3 (late blight resistant chipper) and MSQ070-1(scab and late blight resistant chipper) are being fast-tracked for the chip-processing market. We also have a focused ribavirin-based virus eradication system to generate virus-free tissue culture lines for the industry. About 30 lines are in ribaviran treatment at this time to remove PVS and PVY. This year, about 80 new MSU breeding lines are being put into tissue culture. MSU Variety Releases: ________________________________________________________________________ MSJ147-1 Parentage: NorValley X S440 Developers: Michigan State University and the Michigan Agricultural Experiment Station Plant Variety Protection: Will be considered. Strengths: MSJ147-1 is a round white chip- processing potato that has a bright skin, white flesh and round shape. In addition, it has been determined to store at temperatures below 50°F and maintain low reducing sugar levels into May or June. Weaknesses: Small vine, slow to emerge. Incentives for production: MSJ147-1 produces many A-size tubers that are low in defects, however we are seeing some HH in the large tubers this storage season. Potatoes maintain low reducing sugar content for chip-processing out of the field and from storage. ________________________________________________________________________ 22 ________________________________________________________________________ MSJ126-9Y Parentage: Penta x OP Developers: Michigan State University and the Michigan Agricultural Experiment Station Plant Variety Protection: To Be Applied For. Strengths: MSJ126-9Y is a chip-processing potato with an attractive round appearance with shallow eyes. MSJ126-9Y has a medium vine and an early to mid-season maturity. This variety has resistance to Streptomyces scabies (common scab) stronger than Pike. MSJ126-9Y also has excellent chip-processing long-term storage characteristics and better tolerance to blackspot bruise than Snowden. Incentives for production: Excellent chip-processing quality with long-term storage characteristics, common scab resistance superior to Pike, and good tuber type. ________________________________________________________________________ MSH228-6 Parentage: MSC127-3 x OP Developers: Michigan State University and the Michigan Agricultural Experiment Station Plant Variety Protection: Will be considered. Strengths: MSH228-6 is a chip-processing potato with moderate resistance to Streptomyces scabies (common scab). MSH228-6 also has a promising storage sugar profile and good chip- processing long-term storage characteristics. Incentives for production: Chip-processing quality with long-term storage characteristics, and moderate common scab resistance with good tuber type. ________________________________________________________________________ MSL292-A Parentage: Snowden x MSH098-2 Developers: Michigan State University and the Michigan Agricultural Experiment Station Plant Variety Protection: Will be considered. Strengths: MSL292-A is a chip-processing potato with an attractive round appearance with shallow eyes. MSL292-A has a full-sized vine 23 and an early to mid-season maturity. MSL292-A has above average yield potential and specific gravity similar to Snowden. This variety has excellent chip-processing long-term storage characteristics and a similar to better tolerance to blackspot bruise than Snowden. Incentives for production: Excellent chip-processing quality with long-term storage characteristics, above average yield, specific gravity similar to Snowden, and good tuber type. ________________________________________________________________________ MSL007-B Parentage: MSA105-1 x MSG227-2 Developers: Michigan State University and the Michigan Agricultural Experiment Station Plant Variety Protection: Will be considered. Strengths: MSL007-B is a chip-processing potato with an attractive, uniform round appearance with shallow eyes. This variety has resistance to Streptomyces scabies (common scab) stronger than Pike, with a strong, netted skin. MSL007-B was the most highly merit rated line in the National Chip Processing Trial across eight locations. Incentives for production: Chip-processing quality with common scab resistance superior to Pike, and a uniform, round tuber type. ________________________________________________________________________ MSR061-1 Parentage: MegaChip x NY121 Developers: Michigan State University and the Michigan Agricultural Experiment Station Plant Variety Protection: Will be considered. Strengths: MSR061-1 is a chip-processing potato with resistance to common scab (Streptomyces scabies) and moderate foliar late blight (Phytophthora infestans) resistance. This variety has medium yield similar to Pike and a 1.079 (average) specific gravity and an attractive, uniform, round appearance. MSR061- 1 has a medium vine and an early to mid-season maturity. Incentives for production: Chip-processing quality with common scab resistance similar to Pike, moderate foliar late blight resistance (US8 genotype), and uniform, round tuber type. ________________________________________________________________________ 24 ________________________________________________________________________ MSQ176-5 Parentage: MSI152-A x Missaukee (MSJ461-1) Developers: Michigan State University and the Michigan Agricultural Experiment Station Plant Variety Protection: Will be considered. Strengths: MSQ176-5 is a high-yielding freshmarket potato with bright skin and a uniform smooth, round appearance with an attractive tuber type. This variety has a strong vine and a mid-season maturity. MSQ176-5 has strong foliar resistance to the US8 genotype of late blight. MSQ176-5 also has resistance to Streptomyces scabies (common scab) similar to Pike. Incentives for production: Excellent freshmarket tuber quality and type with foliar late blight resistance and common scab resistance. ________________________________________________________________________ II. Germplasm Enhancement In 2010 we developed genetic mapping populations (both at diploid and tetraploid levels) for late blight resistance, beetle resistance, scab resistance and also for tuber quality traits. We will start to characterize these populations in 2011 and conduct the linkage analysis studies following the SNP genotyping. The diploid genetic material represent material from South American potato species and other countries around the world that are potential sources of resistance to Colorado potato beetle, late blight, potato early die, and ability to cold-chip process. We have used lines with Verticillium wilt resistance, PVY resistance, and cold chip-processing. We are monitoring the introgression of this germplasm through marker assisted selection. Through GREEEN funding, we were able to continue a breeding effort to introgress leptine-based insect resistance using new material selected from USDA/ARS material developed in Wisconsin. We will continue conducting extensive field screening for resistance to Colorado potato beetle at the Montcalm Research Farm and in cages at the Michigan State University Horticulture Farm. We made crosses with late blight resistant diploid lines derived from Solanum microdontum to our tetraploid lines. We have conducted lab-based detached leaf bioassays and have identified resistant lines. These lines are being used crosses to further transmit resistance. III. Integration of Genetic Engineering with Potato Breeding Potato Translation Initiation Factor 4E (eIF4E) over-expression to obtain resistance to PVY in susceptible potato varieties 25 USDA/ARS funded project: USDA PI: Jonathan Whitworth, USDA-ARS, Aberdeen, Idaho. Jonathan.Whitworth@ars.usda.gov 208-397-4181 x112 Cooperator: David Douches, Dept. Crop and Soil Sciences, Michigan State University Summary of the Problem Douchesd@msu.edu 517-355-0271 x 1194 Numerous potato viruses are prevalent worldwide and can cause substantial economic losses. In the US four potato viruses PVY, PVX, PLRV and PVS are most frequently identified, but PVY and its various associated strains is the most common and economically most harmful (Valkonen 2007). These potato viruses are transmitted to the next seed generation through tubers. The use of disease-free tissue culture stocks in combination with state seed certification programs has historically been a source of clean seed to the commercial farmers, but in recent years, the level of PVY in potato certified seed lots has reached problem levels (Whitworth et al. 2005). The extensive spread of various strains of PVY have become very common in seed production due to the amount of PVY symptom-less expression varieties being grown combined with the high numbers of non-persistent PVY vectoring aphids present in potato growing regions. It is difficult to produce seed clean of PVY when the inoculum is so widely distributed throughout seed production regions. The variety, Russet Norkotah and its line selections, make it the second most common variety in the US (NASS 2007). This variety along with Shepody and Silverton Russet are described as being symptom-less carriers of PVY. One solution to this problem is to replace these varieties with new and improved ones. Ideally these varieties would have extreme resistance to all PVY strains, but some advanced breeding lines such as A95109-1 that show great promise still have the weakness of PVY susceptibility. Resistance to PVY common and necrotic (NTN, N:O) strains is critical as the necrotic strains are present in the industry and can cause tuber defects. Michigan State University and other breeding programs are currently using the Ry gene to introduce extreme resistance to PVY into advanced breeding germplasm through conventional breeding combined with marker-assisted selection techniques (Gebhardt et al. 2006). It will take a significant number of years to identify, release and commercialize a new variety that will compete with the market impact of Russet Norkotah. The conventional breeding strategy must be employed; however current technology exists to introduce PVY resistance directly into Russet Norkotah and other PVY susceptible varieties using pathogen-derived resistance (e.g. viral coat protein). NatureMark had released in the late 1990s transgenic lines of Russet Burbank that were resistant to PVY (Kaniewski and Thomas, 2003). It is well known that these and other transgenic potato lines were removed from the market in 2001 when the quick serve restaurant industry was attacked by the anti-biotech activists through media tactics to create concern among the public regarding the food and environmental safety of these potatoes (Simon 2003). Transgenic technology has continued to advance since the 1990s and Simplot scientists have recently developed a new method to introduce native genes into potato without any additional genes or DNA sequences (Rommens et al., 2004). With this 26 technology they can create transgenic potato lines that contain only potato genes rather than genes obtained from other organisms. The public perception of this technology is much more accepting of this transformation technique that employs only the crop’s genes rather than genes from other organisms such are viruses, bacteria, etc. (K. Swords pers. comm.). Research Objectives and Research Plan The new transgenic approach can be applied to the PVY problem in the potato industry. Our overall objective is to conduct studies that will lead to transgenic Russet Norkotah, Silverton Russet, and A95109-1 lines that have PVY resistance conferred by a native resistance gene from potato. Through gene mapping studies Valkonen’s group was able to map the extreme resistance to PVY to Chr. 11 (Hamalainen et al. 1997). A genetic marker has been identified that co-segregates with the extreme resistance to PVY (Ryadg) (Kasai et al. 2000). Valkonen’s group has also made an effort to clone this PVY resistance gene (a LRR-NBS R-gene), but the over- expressed gene they cloned did not confer resistance and they theorized that another non- cloned R-gene in the hotspot on Chr. 11 may be the actual R-gene that confers resistance. In pepper a PVY resistance gene maps to Chr. 3 and provides natural resistance to PVY that is different than the R-gene resistance on Chr. 11. Ruffel et al. (2005) was able to demonstrate that the pot-1 gene in tomato (Solanum lycoperisicum) is an orthologue to the pvr2 gene in pepper. In transient expression assays, they were able to show that the eIF4E gene (referred to as pot-1) accounted for the resistance to PVY in tomato. Using a comparative genomics approach, we have been able to clone the translation initiation factor 4E (eIF4E) gene from potato that may be the orthologue to the recessive PVY resistance conferred by the pvr2 locus in pepper (Capsicum annum). Our eIF4E gene, cloned from potato using the tomato pot-1 primers has an identical sequence length and a 96% sequence homology match to the tomato orthologue that confers PVY resistance in tomato. We hypothesize that the eIF4E gene we cloned is the orthologue of the pot-1 and pvr2 PVY resistance genes in tomato and pepper, respectively. Progress Report source of PVY resistance in potato. RT-PCR and cDNA amplification using gene specific primers allowed amplification of a tomato gene from S. hirsutum accession PI247087. The sequence of the cloned gene was identical to the Genbank sequence identified as pot-1(AY723736). This sequence was subsequently cloned into the Agrobacterium binary vector pSPUD4 which contains a Cauliflower mosaic virus 35S promoter (CaMV 35S) which should express the pot-1 gene constitutively in plants. A previously cloned potato gene with over 96% sequence identity to the S. hirsutum pot-1 gene but lacking the signature amino acid changes in key regions known to be associated with PVY resistance in pepper and tomato was sub-cloned into a pSPUD4 binary vector as well and will be used in transformations as a control. One of the objectives of this research is to test the tomato pot-1 (eIF4E) gene as a 27 Transformation experiments to introduce the S. hirsutum eIF4E gene or the potato gene into the PVY susceptible line E149-5Y were completed resulting in at least 20 independent clones for each gene. Culturing on medium containing kanamycin and PCR was used to confirm the presence of the transgene in each of the independent clones. In addition to the first round of transformation experiments, we now have 10 lines with the S. hirsutum pot-1 gene derived from Russet Norkotah, 25 lines from Classic Russet and over 50 lines from Silverton Russet. Select lines from each of these varieties will be tested by JW this winter. Three PVY strains (O, N NTN) have been selected and increased in tobacco at Aberdeen to use for inoculation of tissue culture potato plants. Tissue culture plants (30 each) of 18 putative PVY resistant potato lines are being sent to JW for greenhouse PVY evaluation this fall. PVY resistance to three PVY strains (O, N and NTN) of the MSE149-5Y lines was evaluated by JW in the winter of 2010. The check line was highly infected by all three strains. Of the transgenic lines, 3 lines (89-3, 89-22 and 89-26) demonstrated little to no PVY accumulated in the plants across the three PVY strains. These lines are being increased for minituber production so that field studies can be conducted in 2011. 28 Funding: Fed. Grant/MPIC 2010 POTATO VARIETY EVALUATIONS D.S. Douches, J. Coombs, K. Zarka, G. Steere, M. Zuehlke, C. Long, W. Kirk, and J. Hao Departments of Crop and Soil Sciences and Plant Pathology Michigan State University East Lansing, MI 48824 Each year, the MSU potato breeding and genetics team conducts a series of INTRODUCTION variety trials to assess advanced potato selections from the Michigan State University and other potato breeding programs at the Montcalm Research Farm (Entrican). In 2010, we tested 182 varieties and breeding lines in the replicated variety trials, plus single observational plots of 186 lines for the Early Observational Trial and 219 lines in the National Chip Processing Trial. The variety evaluation also includes disease testing in the scab nursery (MSU Soils Farm, E. Lansing and Montcalm Research Farm, Lakeview) and foliar and tuber late blight evaluation (Muck Soils Research Farm, Bath). The objectives of the evaluations are to identify superior varieties for fresh or processing markets. The varieties were compared in groups according to market class, tuber type, skin color, and to the advancement in selection. Each season, total and marketable yields, specific gravity, tuber appearance, incidence of external and internal defects, chip color (from the field, 45°F (7.2°C) and 50°F (10°C) storage), as well as susceptibilities to common scab, late blight (foliar and tuber), and blackspot bruising are determined. been an on-going process. In 2010, we saw a significant increase in plot yields as a result of improved trial management. We would like to acknowledge the collaborative effort of Bruce Sackett, Mark Otto (AgriBusiness Consultants), Darryl Warncke, Chris Long, and the Potato Breeding Team. PROCEDURE Entrican, MI. They were planted as randomized complete block designs with two to four replications. The plots were 23 feet (7 m) long and spacing between plants was 10 inches (25.4 cm). Inter-row spacing was 34 inches (86.4 cm). Supplemental irrigation was applied as needed. The field experiments were conducted on a sandy loam soil that was in corn the previous year and in potatoes 4 years previously. The most advanced selections in the breeding program were harvested at two dates to evaluate early and late harvest potential (Early Harvest Trial). These same Improving agronomic performance of plots at the Montcalm Research Farm has Ten field experiments were conducted at the Montcalm Research Farm in 29 clones also harvested at a later standard harvest date, included in the various other variety trials. The Date of Harvest Early and Late Trials were replaced by the Early Trial entries being included in other trials for the second (Late) harvest. The most advanced selections were tested in the Advanced trial, representing selections at a stage after the Adaptation Trial. The other field trials were the North Central, Russet, Adaptation (chip-processors and tablestock), and Preliminary (chip-processors and tablestock). Note: We also conducted an early harvest observation trial (90 days), to screen newer lines from the breeding program for early performance potential as out of the field chip-processing and tablestock varieties. The early observational trial is discussed in the breeding report. 2010 was the first year of the National Chip Processing Breeder Trial (NCPT). The purpose of the trial is to evaluate early generation breeding lines from the US public breeding programs for their use in chip-processing. The NCPT has 8 sites (North: NY, MI, WI, ND and South: NC, FL, TX, CA) in addition to a scab trial in MN. A total of 220 lines were tested as 15-hill single observation plots. The NCPT trial is discussed in the breeding report. In each of these trials, the yield was graded into four size classes, incidence of external and internal defects in >3.25 in. (8.25 cm) diameter (or 10 oz. (283.5 g) for Russet types) potatoes were recorded. Samples were taken for specific gravity, chipping, disease tests and bruising tests. Chip quality was assessed on 25-tuber composite sample from four replications, taking two slices from each tuber. Chips were fried at 365°F (185°C). The chip color was measured visually with the SFA 1-5 color chart. Tuber samples were also stored at 45°F (7.2°C) and 50°F (10°C) for chip-processing out of storage in January and March. Advanced selections are also placed in the MPIC B.F. Burt Cargill Commercial Demonstration Storage in Entrican, MI for monthly sampling. The lines in the agronomic trials were assessed for common scab resistance at the nursery at the MSU Soils Farm, and at a new scab site at the Montcalm Research Farm. There was very strong scab disease pressure at the new Montcalm Scab Disease Nursery. The 2010 late blight trial was conducted at the Muck Soils Research Farm. Maturity ratings (1 early - 5 late) were taken for all variety trial plots in late August to differentiate early and late maturing lines. The simulated blackspot bruise results for average spots per tuber have also been incorporated into the summary sheets. RESULTS A. Chip-processors and Tablestock (Table 1: Early Harvest) There were 12 entries that were evaluated at the early harvest trial. The results are summarized in Table 1. Atlantic, Snowden, Pike and Onaway were used as check varieties. The plot yields were above average in the early harvest (97 days), and specific gravity values were average to slightly below average. Hollow heart was the most prevalent internal defect in the early harvest this year, although only to a limited degree. Atlantic showed the highest incidence of hollow heart in the late harvest (18%). In the Early Trial: 30 Advanced Trial (Table 2) Beacon Chipper – a chip processing line that has high yield potential and early harvest trial, the best yielding lines were Onaway, MSL211-3, Michigan Purple Sport III, and Michigan Purple. MSL211-3 is an attractive, smooth-skinned, round to oval tablestock line with foliar late blight resistance. Michigan Purple Sport III is a unique selection with splashes of purple from a sport of Michigan Purple. Michigan Purple continues to demonstrate early bulking potential for the farm market. B. A summary of the 18 entries evaluated in the Advanced trial results is given in Table 2. Overall, the yields for the Advanced trial (140 days) were above average. The check varieties for this trial were Snowden, Atlantic, and FL1879. The highest yielding lines were Snowden (439 cwt/a), MSL292-A, Kalkaska, MSH228-6, MSQ279-1, and MSQ086-3 (372 cwt/a), followed by Atlantic, MSP515-2, and Beacon Chipper. Hollow heart and vascular discoloration were the predominant internal defects, with FL1879 and Atlantic having the highest levels of hollow heart (33 and 20%, respectively). There was a higher incidence of internal brown spot than typical, with 13% in MSP515-2 and 8% for Atlantic, MSQ070-1, and Kalkaska. Specific gravity was average with five lines having specific gravities equal to or higher than Snowden (1.079): MSQ070-1 (1.088), Atlantic (1.085), MSJ147-1 (1.083), Kalkaska (1.081), and MSL292-A (1.079). All entries in the trial had excellent chip-processing quality out of the field, with an SFA score of 1.0. Many of the MSU breeding lines have moderate to strong scab resistance. Beacon Chipper continues to be consistently high yielding line with good specific gravity, chip quality, and scab resistance. MSH228-6 also continues to be a top agronomically performing clone with scab resistance. Two newer promising chip- processing lines are MSL292-A (chip quality, high yield, good specific gravity, and shows potential as a long-term storage chipper) and MSQ279-1 (good yield and chip quality and scab résistance). Other lines that continue to show promise are MSL007-B, MSJ126-9Y, MSR061-1, MSP270-1, and MSJ147-1. Variety and Advanced Breeding Line Characteristics moderate scab tolerance along with excellent chip-processing quality. Yield performance in the USPB/SFA trials was also high. type and has performed well in on-farm trials. Kalkaska (MSJ036-A) – an MSU chip-processing selection with high yield potential. It also has a high specific gravity and scab resistance. The tuber type of MSJ036-A is round and attractive. We are conducting transformations to lower the reducing sugar in the tubers. MSH228-6 – a chip-processing line with moderate scab resistance. It has a good 31 MSL292-A – a round-white chip-processing line with high yield, good specific gravity, and excellent chip quality that has demonstrated potential for good long-term chip quality. average specific gravity, and good type. This line produces clean chips with good specific gravity and an early maturity, and has storage potential. MSP270-1 – a new round-white chip-processing line with good scab resistance, MSQ279-1 – a round-white chip-processing line with good agronomic performance and excellent chip quality that has good scab tolerance. MSJ126-9Y – an earlier season chip-processing line with excellent chip quality and long-term storage potential. This line also has scab resistance and an attractive type. MSL007-B – an MSU chip-processing selection with strong scab resistance, MSL211-3 – an attractive round-white tablestock line with strong foliar late blight uniform round type, and a unique netted skin. This newer line produces excellent chips with a good specific gravity and average yield. resistance, moderate scab resistance, and an early maturity. scab resistance, strong foliar late resistance, and PVY resistance. This line has an average yield with mid-early maturity. MSL268-D – is also a round-to-slightly oval white tablestock line with moderate MSR061-1 – is also a round-white chip-processing line with good scab resistance, moderate foliar late resistance, and PVY resistance. This line has an average yield with mid-early maturity. In the past the MPIC has sponsored a booth at the Great Lakes Fruit, Vegetable, and Farm Market Expo in December to market Liberator, Michigan Purple, Jacqueline Lee, and new specialty potato varieties to the farm market/roadside stand market segment. The breeding program sponsored the booth in 2009 and 2010 to continue to promote varieties and promising advanced selections that may be of interest to this market segment. There continues to be a strong interest in specialty potato varieties and a growing demand for new, unique potato varieties. We also showcased some of the newer up-and-coming selections from the breeding program to get a sense of the interest from growers who stopped by the booth. C. regional locations) to provide adaptability data for the release of new varieties from Michigan, Minnesota, North Dakota, Wisconsin, and Canada. Twenty-two entries were tested in Michigan in 2010. The clones were from three market classes: Red (5 entries), Russet (5 entries), or Round White (12 entries). The results are presented in Tables 3 The North Central Trial is conducted in a wide range of environments (11 North Central Regional Trial Entries (Tables 3 and 4) 32 Russet Trial (Table 4) Adaptation Trials (Tables 5 and 6) and 4. The MSU lines MSL211-3, MSL268-D, MSM182-1, and MSQ176-5 were the Michigan representatives included in the 2010 North Central Trial. MSL211-3 is an attractive, bright-skinned round to oval white tablestock with late blight resistance and reduced susceptibility to scab. MSL268-D has dual-purpose characteristics; good chip- processing quality and an attractive freshmarket type, combined with late blight resistance, and some early bulking potential. MSM182-1 is a tablestock line with bright- skin, and round type. MSQ176-5 is a late blight resistant tablestock with very uniform, large, round-white tubers and smooth, bright skin. D. We continue to increase our russet breeding efforts to reflect the growing interest in russet types in Michigan. In 2010, 13 lines evaluated after 128 days. The results are summarized in Table 4. Russet Burbank, Russet Norkotah, Silverton Russet were the reference varieties used in the trial. The highest yielding lines were Silverton Russet (337 cwt/a), A98134-2RUS, W6234-4RUS, and AC00395-2RUS (289 cwt/a). Overall, the internal quality in the russet trial was above average; however, hollow heart and vascular discoloration continue to be the most prevalent internal defects. The highest hollow heart level was observed in AC00395-2Rus (60%) and A01124-3Rus (60%). Specific gravity measurements were average to below average with Russet Norkotah at 1.064. Off type and cull tubers were found in nearly all lines tested, with the highest being Russet Burbank (33%). E. chip-processing and tablestock trials. The majority of the lines evaluated in the Adaptation Trial were tested in the Preliminary Trial the previous year. Three reference cultivars (Atlantic, Snowden, and Pike), and 18 advanced breeding lines are reported in the chip-processing trial. The trial was harvested after 139 days and the results are summarized in Table 5. All entries had good out-of-the-field chip scores. Specific gravity values were average for the Montcalm Research Farm (Atlantic was 1.086 and Snowden was 1.080). The highest specific gravity was Atlantic (1.086), followed by MSK409-1 (1084). The greatest hollow heart was noted in MSR159-02 (40%), followed by Atlantic and MSR036-5 (25%). The overall plot yields for this trial were above average in 2010. MSQ035-3 was the highest yielding line in 2010 (514 cwt/a), followed closely by MSS206-2 (504 cwt/a), Missaukee (491 cwt/a), and then Snowden (476 cwt/a). Multiple new breeding lines combine scab resistance and chip-processing: MSQ035-3, MSR036-5, MSR169-8Y and MSR131-2. and check variety. The trial was harvested after 126 days and the results are summarized in Table 6. In general, the yield was above average in this trial and internal defects were low. The greatest amount of hollow heart was seen in Reba (18%). There were a significant number of oversize potatoes in MSS582-1SPL and Reba. The highest yielding line was MSS582-1SPL (round-white with red splashes) at 510 cwt/a, followed The Adaptation Trials are conducted as two separate trials based on market class: In the tablestock trial, 15 advanced breeding lines were evaluated with Onaway 33 The Preliminary trial is the first replicated trial for evaluating new advanced by Reba, MSQ461-2PP, MSQ341-BY, and Onaway (379 cwt/a). Five of the lines have moderate to strong scab resistance. Eight of the 15 lines also had early maturity, similar to Onaway. Promising lines with an attractive type for the tablestock market are MSS582-1SPL, MSQ461-2PP, MSQ341-BY, and MSM288-2Y. Four specialty lines are being considered for release for 2011: MSQ425-4Y (purple splash skin with yellow flesh), MSN215-2P (purple skin with white flesh), MSR226-1R (red skin and red flesh), and Midnight (purple skin with deep purple flesh). F. Preliminary Trials (Tables 7 and 8) selections from the MSU potato breeding program. The division of the trials was based upon pedigree assessment for chip-processing and tablestock utilization. The chip- processing Preliminary Trial (Table 7) had 33 advanced selections and two check varieties (Atlantic and Snowden). The chip-processing trial was harvested after 134 days. Most lines chip-processed well from the field (SFA chip score 1.0 – 1.5). Specific gravity values were average to below average for the trial (Atlantic: 1.090). The MSU lines with the highest specific gravities were MSR127-2, MSU383-1, MSU245-1, and MSU246-1. The yields were above average with Snowden at 423 cwt/a and Atlantic at 417 cwt/a. The highest yielding lines were MSU379-1 (547 cwt/a), MR148-A, MSR127- 2, MSU383-1, and MST220-8 (434 cwt/a). Sixteen of the lines (46%) were classified to be resistant or moderately resistant to scab (< 1.5 scab disease rating). The greatest internal defects were hollow heart (Atlantic, MSU245-1, and MSQ029-1 at 45%), and 55% internal brown spots in Atlantic. Many of the lines in the Preliminary Trial combine good agronomic performance with chip quality, specific gravity, and scab resistance. (Onaway was the check variety). This tablestock trial was harvested and evaluated after 126 days. Eight of the selections were scab resistant or moderately resistant (< 1.5 scab disease rating). MSU161-1 (490 cwt/a), MSR214-2P, MST386-1P, MST285-2, and Onway (417 cwt/a ) were the highest yielding lines. In general, there was a low incidence of internal defects. In addition to traditional round white, red-skinned, and yellow flesh freshmarket categories, there are some unique specialty lines. Zongshu 3 and Jingshu 2 were two lines from the Chinese breeding program that were also evaluated. G. Potato Scab Evaluation (Table 9) conducted to assess resistance to common scab. In 2010, we added two new scab testing locations. A site at the Montcalm Research Farm with high common scab disease pressure was chosen as a second testing location for the early generation observational trial (240 lines), and two replications of the scab variety trial (158 lines). Additionally, we added a replicated On-Farm scab trial (32 lines), which is summarized in the Research Report. We use a rating scale of 0-5 based upon a combined score for scab Table 8 summarizes the 35 tablestock lines evaluated in the Preliminary Trial Each year, a replicated field trial at the MSU Soils Farm (E. Lansing, MI) is 34 coverage and lesion severity. Usually examining one year's data does not indicate which varieties are resistant but it should begin to identify ones that can be classified as susceptible to scab. Our goal is to evaluate important advanced selections and varieties in the study at least three years to obtain a valid estimate of the level of resistance in each line. The 2010 scab ratings are based upon the Montcalm Research Farm site. Table 9 categorizes many of the varieties and advanced selections tested in 2010 along with three-year averages where applicable. The varieties and breeding lines are placed into six categories based upon scab infection level and lesion severity. A rating of 0 indicates zero scab infection. A score of 1.0 indicates a trace amount of infection. A moderate resistance (1.2 – 1.8) correlates with <10% infection. Scores of 4.0 or greater are found on lines with >50% infection and severe pitted lesions. The check varieties Russet Burbank, Russet Norkotah, GoldRush, Red Norland, Red Pontiac, Onaway, Pike, Atlantic, and Snowden can be used as references (bolded in Table 9). The table is sorted in ascending order by 2010 rating. This year’s results continue indicate that we have been able to breed numerous lines for the chip-processing and tablestock markets with resistance to scab. A total of 60 lines, of the 158 tested, had a scab rating of 1.5 (better than or equivalent to Pike) or lower in 2010. Most notable scab resistant MSU lines are MSH228-6, Kalkaska, MSJ126-9Y, MSL007-B, MSM037- 3, MSN215-2P, MSP270-1, MSR036-5, MSR102-3 and MSR169-8Y; as well as some earlier generation lines MSS297-3, MSS544-1R, MSU383-1, and MSU384-1. The greater number of MSU lines in the resistant and moderately resistant categories indicates we are making progress in breeding more scab resistant lines for the chip-processing and tablestock markets. There are also an increasing number of scab resistant lines that also have late blight resistance and PVY resistance. We also continue to conduct early generation scab screening on selections in the breeding program beginning after one year. Of the 240 early generation selections that were evaluated, 98 were resistant (scab rating of ≤ 1.0). Scab results from the disease nursery are also found in the Trial Summaries (Tables 2-8). H. Late Blight Trial (Table 10) In 2010, the late blight trial was planted at the Muck Soils Research Farm. As in previous years, 196 entries were planted in replication for evaluation in replicated plots. These include lines tested in the agronomic variety trial (157 lines) and entries in the National Late Blight Variety Trial (39 lines). Block planting full rows of advanced selections provide a better assessment of the late blight resistance of these lines. We also planted 132 early generation breeding lines that have a late blight resistant pedigree. The field was planted on June 7. The trials were inoculated on August 3 with a US-8 genotype of P. infestans. Late blight infection was identified in the plots 10 days after inoculation. The plots were evaluated more than seven times over a 45 day period following inoculation. We need to note that the disease reaction in the plots was not typical to the previous years’ ratings. All disease lesions tested were identified as US-22, which would explain the higher disease ratings (susceptibility) on lines with late blight resistance to US-8 (Tollocan-based resistance lines Jacqueline Lee, Missaukee, etc.). In 35 Evaluations of advanced seedlings and new varieties for their susceptibility to 2010, twenty-nine lines had moderate to strong late blight resistance to US-22. These were from various late blight resistance sources (Torridon, Stirling, NY121, B0718-3, etc.). Table 10 lists select lines in the foliar resistance and susceptibility categories. I. Blackspot Bruise Susceptibility (Table 11) blackspot bruising are also important in the variety evaluation program. Based upon the results collected over the past years, the non-bruised check sample has been removed from our bruise assessment. A composite bruise sample of each line in the trials consisted of 25 tubers (a composite of 4 replications) from each line, collected at the time of grading. The 25 tuber sample was held in 50°F (10°C) storage overnight and then was placed in a hexagon plywood drum and tumbled 10 times to provide a simulated bruise. The samples were peeled in an abrasive peeler in October and individual tubers were assessed for the number of blackspot bruises on each potato. These data are shown in Table 11. The bruise data are represented in two ways: percentage of bruise free potatoes and average number of bruises per tuber. A high percentage of bruise-free potatoes is the desired goal; however, the numbers of blackspot bruises per potato is also important. Cultivars which show blackspot incidence greater than Atlantic are approaching the bruise-susceptible rating. In addition, the data is grouped by trial, since the bruise levels can vary between trials. Conducting the simulated bruise on 50°F (10°C) tubers has helped to standardize the bruise testing. We are observing less variation between trials since we standardized the handling of the bruise sample. In 2010, the bruise levels were comparable to previous years. The most bruise resistant MSU breeding lines this year from the Advanced trial were MSP270-1, MSQ440-2, MSH228-6, MSQ086-3, MSJ126-9Y, MSR061-1, and MSJ147-1. The most susceptible lines from the Advanced trial were MSP515-2, Snowden, MSP459-5, and Atlantic. The Adaptation Trial lines with the best bruise resistance were MSS108-1, MSQ432-2PP, MSR102-3, MSR159-02, MSM288-2Y, MSS544-1R, MSN105-1, MSR157-1Y, and MSS576-05SPL. Of the earlier generation breeding lines (Preliminary Trial), the most bruise resistant were MSR160-2Y, MST202-5, A00188-3C, MSU384-1, CO00188-4W, MSU379-1, MST437-1, MSQ130-4, MSU202-1P, MSR297-A, 1991-563- 18, MSQ405-1PP, MST406-2RR, and MSU613-1. The most bruise resistant russet entries were A01124-3RUS, Silverton Russet, W6234-4RUS, CO99053-3RUS, and A98134-2RUS; the most susceptible were W8946-1RUS-NCR and W2683-2RUS. The most bruise resistant entries in the US Potato Board/Snack Food Association Trial were MSJ126-9Y, NY138, and W2978. While W2310-3, Atlantic, Snowden, and W5015-12 were the most bruise susceptible in this trial. 36 Table 1 EARLY HARVEST TRIAL MONTCALM RESEARCH FARM May 4 to August 9, 2010 (97 days) CWT/A PERCENT OF TOTAL1 MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS PERCENT (%) 3-YR AVG 11 * Two-Year Average TOTAL US#1 369 338 325 321 315 302 293 287 221 203 160 154 274 101 US#1 Bs As OV PO 3 85 1 87 89 0 1 91 0 86 84 0 1 86 1 91 0 68 76 1 0 56 65 3 LINE Onaway MSL211-3 MI Purple Sport III MI Purple Snowden Atlantic MSM037-3 MSM171-A MSQ425-4Y Pike MSQ086-3 MSN215-2P MEAN HSD0.05 1SIZE: B: < 2 in.; A: 2-3.25 in.; OV: > 3.25 in.; PO: Pickouts. 2CHIP SCORE: Snack Food Association Scale (Out of the field); Ratings: 1-5; 1: Excellent, 5: Poor. 3QUALITY: HH: Hollow Heart; BC: Brown Center; VD: Vascular Discoloration; IBS: Internal Brown Spot. Percent of 40 Oversize and/or A-size tubers cut. 4MATURITY RATING: August 3, 2010; Ratings 1-5; 1: Early (vines completely dead); 5: Late (vigorous vine, some flowering). SP GR 1.062 1.066 1.068 1.070 1.081 1.085 1.065 1.055 1.065 1.075 1.066 1.069 1.069 0.006 433 387 364 354 367 361 340 315 326 266 283 236 336 102 12 11 10 9 14 16 13 8 32 23 44 32 TUBER QUALITY3 CHIP SCORE2 HH VD IBS BC 0 0 0 0 0 0 0 0 0 0 0 0 - - - - 1.0 1.0 1.0 - 1.0 1.0 1.0 - 0 0 5 5 3 18 0 8 3 5 0 0 0 0 0 3 0 0 0 0 0 0 0 0 8 0 5 3 8 5 0 5 0 0 0 0 81 81 80 84 83 81 84 75 68 75 56 64 4 6 9 7 3 3 2 16 0 1 0 1 MAT4 2.2 3.0 3.0 3.0 3.5 3.5 3.0 2.9 2.7 3.8 4.3 2.9 US#1 CWT/A 342* 295* - - - 257 259* 288 - 207 219* - 37 Table 2 ADVANCED TRIAL MONTCALM RESEARCH FARM May 4 to September 21, 2010 (140 days) CWT/A PERCENT OF TOTAL1 PERCENT (%) CHIP TUBER QUALITY3 TOTAL MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS 3-YR AVG US#1 CWT/A - - 333* 347 347 304 - 322 276* 371 287 282* 1.5 1.3 1.2 0.4 0.2 0.4 2.2 1.4 1.3 0.7 1.0 0.2 0.8 0.6 0.6 0.2 1.6 0.6 0.9 * Two-Year Average 214* 240 244 - 208 197 10 3 1 5 14 0 6 12 24 14 1 6 2 3 1 1 1 0 1 0 0 2 1 0 0 0 1 1 0 0 0 0 0 0 0 8 10 14 21 9 9 27 13 16 5 8 20 11 19 15 23 25 37 33 80 83 78 84 77 72 81 71 71 77 79 82 79 82 75 75 62 59 490 468 504 427 411 514 410 418 370 373 422 353 382 306 339 318 344 265 395 153 US#1 439 403 400 383 373 372 356 349 349 339 338 314 310 259 259 240 217 158 325 149 US#1 Bs As OV PO SP GR SCORE2 HH VD IBS BC SCAB4 MAT5 BRUISE6 90 86 79 90 91 72 87 84 94 91 80 89 81 85 76 75 63 59 LINE Snowden MSL292-A Kalkaska (MSJ036-A) MSH228-6 MSQ279-1 MSQ086-3 Atlantic MSP515-2 Beacon Chipper FL1879 MSQ070-1 MSQ440-2 MSL007-B MSJ126-9Y MSR061-1 MSP270-1 MSP459-5 MSJ147-1 MEAN HSD0.05 LBR Line(s) demonstrated foliar resistance to Late Blight ( Phytopthora infestans ) in inoculated field trials at the MSU Muck Soils Research Farm. 1SIZE: B: < 2 in.; A: 2-3.25 in.; OV: > 3.25 in.; PO: Pickouts. 2CHIP SCORE: Snack Food Association Scale (Out of the field); Ratings: 1-5; 1: Excellent, 5: Poor. 3QUALITY: HH: Hollow Heart; BC: Brown Center; VD: Vascular Discoloration; IBS: Internal Brown Spot. Percent of 40 Oversize and/or A-size tubers cut. 4SCAB DISEASE RATING: MSU Scab Nursery; 0: No Infection; 1: Low Infection <5%; 3: Intermediate; 5: Highly Susceptible. 5MATURITY RATING: August 24, 2010; Ratings 1-5; 1: Early (vines completely dead); 5: Late (vigorous vine, some flowering). 6BRUISE: Simulated blackspot bruise test average number of spots per tuber. 1.079 1.079 1.081 1.073 1.072 1.074 1.085 1.077 1.075 1.072 1.088 1.055 1.074 1.070 1.077 1.070 1.070 1.083 1.075 0.007 2.1 1.2 3.3 2.4 3.6 2.9 1.9 3.0 2.8 2.0 3.6 2.0 2.7 2.1 2.0 3.0 2.5 2.9 2.5 1.4 2.9 2.5 1.5 1.0 1.3 2.3 2.9 2.3 2.0 3.5 1.3 1.8 1.0 1.0 1.3 1.0 3.0 1.3 1.9 2.3 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 8 3 3 8 3 0 20 5 5 33 3 0 3 0 8 0 0 0 50 0 8 25 0 5 8 10 35 13 8 38 10 20 5 3 3 0 0 0 8 0 0 0 8 13 0 5 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 38 Table 3 CWT/A TOTAL NORTH CENTRAL REGIONAL TRIAL MONTCALM RESEARCH FARM May 4 to September 7, 2010 (126 days) MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS PERCENT (%) 3-YR AVG 10 23 11 9 17 10 10 15 16 15 21 16 17 13 23 16 21 44 81 75 82 75 77 66 72 77 81 78 77 75 79 84 74 82 76 53 8 2 7 14 6 23 15 8 1 6 1 8 3 4 3 0 1 2 2 0 1 2 1 1 3 0 2 1 1 1 1 0 0 1 2 1 PERCENT OF TOTAL1 CHIP TUBER QUALITY3 458 509 433 420 451 411 421 416 419 382 370 331 328 287 322 282 295 365 383 158 US#1 406 391 382 375 372 367 365 352 343 321 289 274 270 251 248 232 227 201 315 155 US#1 US#1 Bs As OV PO SP GR SCORE2 HH VD IBS BC SCAB4 MAT5 BRUISE6 CWT/A 89 77 88 89 83 89 87 85 82 84 78 83 82 87 77 82 77 55 LINE MSL211-3 ND8555-8R Snowden Atlantic W5015-12 MSQ176-5 Red Pontiac NorValley MSL268-D MSM182-1 ND8307C-3 ND8229-3RUS W2609-1R Red Norland W2978-3 W2717-5 W2310-3 ND8314-1R MEAN HSD0.05 LBR Line(s) demonstrated foliar resistance to Late Blight ( Phytopthora infestans ) in inoculated field trials at the MSU Muck Soils Research Farm. All the lines in the Round White Trial in 2008 were North Central Regional Trial entries. 1SIZE: B: < 2 in.; A: 2-3.25 in.; OV: > 3.25 in.; PO: Pickouts. 2CHIP SCORE: Snack Food Association Scale (Out of the field); Ratings: 1-5; 1: Excellent, 5: Poor. 3QUALITY: HH: Hollow Heart; BC: Brown Center; VD: Vascular Discoloration; IBS: Internal Brown Spot. Percent of 40 Oversize and/or A-size tubers cut. 4SCAB DISEASE RATING: MSU Scab Nursery; 0: No Infection; 1: Low Infection <5%; 3: Intermediate; 5: Highly Susceptible. 5MATURITY RATING: August 24, 2010; Ratings 1-5; 1: Early (vines completely dead); 5: Late (vigorous vine, some flowering). 6BRUISE: Simulated blackspot bruise test average number of spots per tuber. 1.068 1.067 1.081 1.086 1.085 1.066 1.061 1.072 1.081 1.068 1.087 1.076 1.058 1.055 1.072 1.088 1.086 1.063 1.073 0.006 2.5 1.5 1.0 1.5 1.0 1.0 3.5 1.0 1.0 2.5 1.0 ! 1.0 2.5 2.0 1.0 1.5 1.0 3.0 - - 307 - - - - - - 330 332 316* 292* 1.0 1.1 1.4 1.4 2.4 0.6 0.7 1.2 1.5 1.2 0.8 2.0 0.4 0.2 0.5 1.2 1.9 1.0 1.1 * Two-Year Average 260* 244* - - - 2.2 2.0 2.9 2.9 3.0 3.0 4.5 2.3 3.0 3.0 1.5 1.0 1.0 2.0 3.5 3.0 2.0 3.0 2.5 2.3 1.3 1.0 1.6 1.8 2.3 2.0 2.1 1.4 1.8 2.0 1.6 2.3 1.3 1.5 1.1 1.1 2.1 1.0 1.6 0.8 0 3 18 53 28 23 10 0 0 5 5 3 0 3 0 5 5 5 3 0 10 13 0 3 0 0 10 3 3 0 0 3 0 10 0 5 0 3 0 13 10 5 0 0 0 13 0 0 3 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 0 39 Table 4 RUSSET TRIAL MONTCALM RESEARCH FARM May 4 to September 9, 2010 (128 days) CWT/A PERCENT OF TOTAL1 PERCENT (%) TUBER QUALITY2 MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS 3-YR AVG US#1 CWT/A 322 - - - 289 - - - 0.3 0.4 0.4 0.6 0.5 2.6 0.0 1.5 0.6 0.4 0.1 0.8 0.6 0.7 * Two-Year Average 235* 271 155 - - TOTAL 65 65 62 65 79 65 67 57 58 67 60 39 50 23 8 15 6 5 11 12 1 8 12 2 3 0 2 3 6 3 3 4 8 5 6 3 1 33 0 385 411 390 408 331 330 291 391 323 241 252 293 170 324 139 US#1 88 74 77 71 84 76 79 58 67 79 62 42 50 US#1 337 302 300 289 278 252 231 228 215 191 156 124 84 230 147 Bs As OV PO SP GR HH VD IBS BC SCAB3 MAT4 BRUISE5 10 24 17 26 13 20 13 36 27 18 37 25 50 LINE Silverton Russet A98134-2RUS W6234-4RUS AC00395-2RUS MSN170-A** W2683-2RUS A01124-3RUS W8946-1RUS Goldrush CO99053-3RUS Russet Norkotah Russet Burbank A98289-1RUS MEAN HSD0.05 **Not Russet lines LBR Line(s) demonstrated foliar resistance to Late Blight ( Phytopthora infestans ) in inoculated field trials at the MSU Muck Soils Research Farm. 1SIZE: B: < 4 oz.; A: 4-10 oz.; OV: > 10 oz.; PO: Pickouts. 2QUALITY: HH: Hollow Heart; BC: Brown Center; VD: Vascular Discoloration; IBS: Internal Brown Spot. Percent of 40 Oversize and/or A-size tubers cut. 3SCAB DISEASE RATING: MSU Scab Nursery; 0: No Infection; 1: Low Infection <5%; 3: Intermediate; 5: Highly Susceptible. 4MATURITY RATING: August 24, 2010; Ratings 1-5; 1: Early (vines completely dead); 5: Late (vigorous vine, some flowering). 5BRUISE: Simulated blackspot bruise test average number of spots per tuber. 1.070 1.071 1.079 1.091 1.078 1.071 1.075 1.091 1.065 1.074 1.064 1.073 1.066 1.074 0.005 3 0 8 60 5 8 60 0 0 8 0 5 0 5 15 5 15 0 3 5 8 15 18 5 10 20 2.9 2.6 1.8 2.6 1.7 2.9 3.1 3.8 1.5 3.3 1.4 2.0 2.0 2.4 1.3 0 0 0 0 0 3 3 3 0 0 0 0 5 0 0 0 0 0 0 0 0 0 0 0 0 0 1.0 1.3 3.5 1.0 1.8 1.0 1.5 1.3 1.0 2.0 2.3 2.0 0.5 1.5 2.3 40 Table 5 ADAPTATION TRIAL, CHIP-PROCESSING LINES MONTCALM RESEARCH FARM May 4 to September 20, 2010 (139 days) CWT/A PERCENT OF TOTAL1 PERCENT (%) CHIP TUBER QUALITY3 MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS TOTAL 8 4 14 10 9 12 9 20 20 14 17 22 14 22 33 28 17 39 12 17 39 84 76 79 83 77 81 64 70 77 78 76 75 67 76 66 69 78 60 69 78 55 8 19 6 7 10 6 21 4 3 6 7 3 14 1 1 2 4 1 12 5 2 0 1 0 0 4 1 6 6 0 2 0 1 4 0 0 1 1 1 7 0 4 561 531 576 528 468 434 428 486 450 395 343 354 330 338 383 350 298 380 256 225 294 400 199 US#1 514 504 491 476 407 378 365 360 359 333 286 276 269 262 256 249 243 230 207 187 169 325 193 US#1 Bs As OV PO SP GR SCORE2 HH VD IBS BC SCAB4 MAT5 BRUISE6 92 95 85 90 87 87 85 74 80 84 83 78 82 77 67 71 82 60 81 83 57 LINE MSQ035-3 MSS206-2 Missaukee Snowden MSQ432-2PP Atlantic MSR036-5 MSR058-1 MSR169-8Y MSK409-1 MSS026-2Y MSS108-1 MSR159-02 CO95051-7W MSR131-2 MSN148-A Pike MSQ558-2RR MSR102-3 MSS258-1 MSR226-1RR MEAN HSD0.05 LBR Line(s) demonstrated foliar resistance to Late Blight (Phytopthora infestans ) in inoculated field trials at the MSU Muck Soils Research Farm. 1SIZE: B: < 2 in.; A: 2-3.25 in.; OV: > 3.25 in.; PO: Pickouts. 2CHIP SCORE: Snack Food Association Scale (Out of the field); Ratings: 1-5; 1: Excellent, 5: Poor. 3QUALITY: HH: Hollow Heart; BC: Brown Center; VD: Vascular Discoloration; IBS: Internal Brown Spot. Percent of 40 Oversize and/or A-size tubers cut. 4SCAB DISEASE RATING: MSU Scab Nursery; 0: No Infection; 1: Low Infection <5%; 3: Intermediate; 5: Highly Susceptible. 5MATURITY RATING: August 24, 2010; Ratings 1-5; 1: Early (vines completely dead); 5: Late (vigorous vine, some flowering). 6BRUISE: Simulated blackspot bruise test average number of spots per tuber. 1.075 1.065 1.075 1.080 1.070 1.086 1.078 1.076 1.081 1.084 1.080 1.072 1.080 1.079 1.072 1.083 1.078 1.066 1.078 1.059 1.060 1.075 0.009 0 0 0 10 3 25 25 8 3 13 5 0 40 0 0 3 3 0 8 0 0 5 15 3 23 0 3 10 20 5 18 8 10 5 13 15 3 8 0 10 0 0 1.0 1.5 1.0 1.0 2.0 1.0 1.5 1.0 1.0! 1.0 1.0 2.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0! 0 0 5 0 0 8 0 0 0 3 0 0 5 0 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1.0 2.5 2.5 2.9 2.0 2.9 1.0 1.5 1.0 1.3 3.0 1.5 2.0 1.5 1.0 1.5 1.1 2.3 1.0 2.0 3.0 1.8 2.3 2.3 2.3 2.4 2.6 2.5 1.9 2.5 2.5 2.6 2.0 2.8 2.5 2.9 2.9 3.1 2.8 2.1 1.3 3.4 1.3 1.6 2.4 1.0 2.2 0.9 1.5 1.6 0.4 1.9 1.2 1.5 1.0 2.6 1.5 0.3 0.6 2.0 1.0 1.9 0.8 1.8 0.5 0.8 0.6 1.3 41 Table 6 ADAPTATION TRIAL, TABLESTOCK LINES MONTCALM RESEARCH FARM May 4 to September 7, 2010 (126 days) CWT/A PERCENT OF TOTAL1 PERCENT (%) TUBER QUALITY2 MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS 94 95 89 87 88 82 74 82 88 73 87 72 74 71 50 64 5 5 10 13 11 17 25 18 10 26 13 28 23 22 37 36 78 81 85 84 82 81 74 81 82 72 83 72 74 71 50 64 17 14 3 3 6 1 0 1 6 1 4 0 0 0 0 0 1 0 1 0 1 1 0 0 2 1 1 0 3 7 12 0 541 494 465 458 432 447 483 422 361 413 307 359 340 338 309 219 399 149 US#1 TOTAL US#1 Bs As OV PO SP GR HH VD IBS BC SCAB3 MAT4 BRUISE5 510 469 412 399 379 364 358 347 318 302 266 259 251 240 155 140 323 134 LINE MSS582-1SPL Reba MSQ461-2PP MSQ341-BY Onaway MSN230-1RY MSM288-2Y MSS576-05SPL MSL228-1SPL MSQ134-5 MSR157-1Y MSQ425-4Y MSS514-1PP MSN215-2P Jacqueline Lee MSS544-1R MEAN HSD0.05 LBR Line(s) demonstrated foliar resistance to Late Blight (Phytopthora infestans ) in inoculated field trials at the MSU Muck Soils Research Farm. NCR North Central Regional Entry 1SIZE: B: < 2 in.; A: 2-3.25 in.; OV: > 3.25 in.; PO: Pickouts. 2QUALITY: HH: Hollow Heart; BC: Brown Center; VD: Vascular Discoloration; IBS: Internal Brown Spot. Percent of 40 Oversize and/or A-size tubers cut. 3SCAB DISEASE RATING: MSU Scab Nursery; 0: No Infection; 1: Low Infection <5%; 3: Intermediate; 5: Highly Susceptible. 4MATURITY RATING: August 24, 2010; Ratings 1-5; 1: Early (vines completely dead); 5: Late (vigorous vine, some flowering). 5BRUISE: Simulated blackspot bruise test average number of spots per tuber. 1.074 1.072 1.079 1.078 1.060 1.087 1.071 1.071 1.077 1.074 1.075 1.067 1.061 1.072 1.079 1.059 1.072 0.006 2.0 2.5 2.0 1.5 2.1 2.0 3.0 2.0 1.8 2.5 1.3 2.5 2.0 1.0 3.3 1.0 2.0 2.3 2.3 2.8 1.9 2.5 1.7 2.6 1.5 1.9 1.8 3.0 2.4 1.9 2.0 1.6 2.6 1.6 2.1 1.0 0.5 1.4 0.4 0.5 1.1 1.9 0.1 0.4 0.5 0.6 0.3 1.5 0.5 0.6 0.9 0.1 0.7 0 18 0 0 0 3 3 0 3 0 0 0 0 0 0 0 3 23 0 18 30 13 13 3 10 5 10 15 0 10 8 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 42 Table 7 LINE MSU379-1 MSR148-4 MSR127-2 MSU383-1 MST220-8 Snowden CO02033-1W Atlantic NY139 AF2291-10 MSU384-1 MSQ130-4 CO02024-9W MSU389-1 MST191-2Y MSNDU030-1 CO02321-4W CO00197-3W MSU088-1 MST306-1 MSU245-1 MST424-3 MST437-1 MSU246-1 CO00188-4W MSS297-3 MSQ029-1 MSU245-2 PRELIMINARY TRIAL, CHIP-PROCESSING LINES MONTCALM RESEARCH FARM May 4 to September 15, 2010 (134 days) MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS CWT/A PERCENT OF TOTAL1 PERCENT (%) CHIP TUBER QUALITY3 US#1 TOTAL US#1 Bs As OV PO SP GR SCORE2 HH VD IBS BC SCAB4 MAT5 BRUISE6 547 534 486 446 434 423 422 417 416 403 393 379 377 370 367 364 363 361 356 351 325 308 304 301 294 290 288 270 604 638 575 488 522 478 512 483 466 455 444 452 492 425 471 437 425 482 421 481 416 345 364 381 395 391 338 332 91 84 84 91 83 88 82 86 89 89 88 84 77 87 78 83 85 75 85 73 78 89 84 79 75 74 85 81 8 16 16 7 15 10 12 11 10 11 10 16 22 11 21 16 14 21 15 26 20 9 13 21 25 26 13 18 80 84 84 78 78 76 78 75 86 83 84 76 75 84 75 77 76 75 83 73 78 84 72 77 73 74 74 77 11 0 0 13 6 12 4 11 3 5 4 7 1 3 3 7 10 0 2 0 0 5 11 2 2 0 11 4 1 0 0 1 1 1 5 2 1 1 1 0 1 2 1 1 1 4 0 1 2 2 3 0 1 0 2 1 1.071 1.073 1.091 1.088 1.071 1.079 1.089 1.090 1.085 1.086 1.083 1.074 1.078 1.074 1.084 1.080 1.082 1.080 1.084 1.078 1.088 1.069 1.084 1.088 1.074 1.074 1.076 1.081 1.0 1.0 1.0 1.0 1.5 1.0 1.0 1.0 1.0 1.0 1.0 1.5 1.0 - 1.0! 1.0 1.0 1.0 1.0 1.5 1.0 1.0 1.0 1.0 1.0 1.0 1.5 1.0 0 0 0 10 20 25 20 45 0 10 0 25 0 0 0 10 10 0 0 0 45 0 10 5 0 0 45 20 0 20 0 5 0 10 25 5 20 25 10 0 0 0 0 5 0 15 0 0 0 15 5 20 10 0 0 15 0 10 0 0 0 0 10 55 0 5 10 10 0 0 0 0 10 0 0 5 0 0 0 5 0 0 0 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1.5 2.5 1.0 1.0 1.5 3.0 3.5 3.0 2.0 2.0 1.0 2.0 3.0 - 3.0 1.5 3.0 3.5 3.0 1.5 - 1.5 2.5 - 1.5 1.0 1.5 - 2.8 2.0 3.8 1.5 3.3 2.8 2.8 2.3 3.0 2.5 2.8 2.3 3.0 1.8 2.8 2.3 2.0 1.8 2.8 2.0 2.3 2.0 2.5 2.5 1.3 2.3 4.5 3.3 0.2 1.0 2.3 1.4 0.8 1.2 1.1 1.5 0.9 1.4 0.2 0.4 0.7 - 1.5 1.0 1.3 0.7 1.2 0.4 0.6 1.1 0.4 1.6 0.2 1.2 0.5 0.6 43 Table 7 LINE Pike MST441-1 MSU358-2 A01143-3C A00188-3C AC01151-5W MST202-5 MSR160-2Y MEAN HSD0.05 PRELIMINARY TRIAL, CHIP-PROCESSING LINES MONTCALM RESEARCH FARM May 4 to September 15, 2010 (134 days) CWT/A PERCENT OF TOTAL1 PERCENT (%) CHIP TUBER QUALITY3 MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS US#1 TOTAL US#1 Bs 80 74 87 76 67 66 61 39 18 25 12 15 29 31 36 61 269 253 251 247 230 206 147 126 342 233 338 341 291 326 342 310 239 320 423 225 As 74 69 74 76 67 66 61 39 OV PO 6 5 13 0 0 0 0 0 2 1 1 10 4 3 2 0 SP GR SCORE2 HH VD IBS BC SCAB4 MAT5 BRUISE6 1.076 1.072 1.079 1.078 1.082 1.076 1.064 1.083 2.0 1.3 1.8 3.5 2.5 2.8 1.0 2.0 1.0 1.0 - 1.5 1.5 3.5 1.5 2.0 0.6 0.8 1.2 0.6 0.1 0.7 0.0 0.0 1.0 1.5 1.0 1.5 1.0 1.0 1.0 1.5 10 0 0 5 0 0 0 0 5 0 0 0 10 0 30 0 0 0 0 25 0 15 0 0 0 0 0 0 0 0 0 0 1.080 0.012 2.0 2.3 2.4 1.8 0.8 LBR Line(s) demonstrated foliar resistance to Late Blight (Phytopthora infestans ) in inoculated field trials at the MSU Muck Soils Research Farm. 1SIZE: B: < 2 in.; A: 2-3.25 in.; OV: > 3.25 in.; PO: Pickouts. 2CHIP SCORE: Snack Food Association Scale (Out of the field); Ratings: 1-5; 1: Excellent, 5: Poor. 3QUALITY: HH: Hollow Heart; BC: Brown Center; VD: Vascular Discoloration; IBS: Internal Brown Spot. Percent of 20 Oversize and/or A-size tubers cut. 4SCAB DISEASE RATING: MSU Scab Nursery; 0: No Infection; 1: Low Infection <5%; 3: Intermediate; 5: Highly Susceptible. 5MATURITY RATING: August 24, 2010; Ratings 1-5; 1: Early (vines completely dead); 5: Late (vigorous vine, some flowering). 6BRUISE: Simulated blackspot bruise test average number of spots per tuber. 44 Table 8 LINE MSU161-1 MSR214-2P MST386-1P MST285-2 Onaway CO99256-2R MSU320-2Y MSU613-1 Colorado Rose MSU202-1P MSU279-1 Midnight W5767-1R MSU500-2SPL MSU200-5PP Zongshu 3 MSNDU022-1 MSNDU045-1 CO00291-5R MSU616-3P MSR217-1R MSR297-A MSU616-1PP Jingshu 2 MST406-2RR MSR241-4RY Sieglinde MSQ405-1PP PRELIMINARY TRIAL, TABLESTOCK LINES MONTCALM RESEARCH FARM May 4 to September 7, 2010 (126 days) MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS CWT/A PERCENT OF TOTAL1 PERCENT (%) CHIP TUBER QUALITY3 US#1 TOTAL US#1 Bs As OV PO SP GR SCORE2 HH VD IBS BC SCAB4 MAT5 BRUISE6 490 457 454 419 417 398 393 350 330 322 307 286 284 280 242 242 238 225 222 197 194 173 168 154 146 120 75 72 529 543 509 481 469 510 462 385 390 376 412 415 334 466 278 302 282 315 268 282 238 211 276 291 213 204 217 159 93 84 89 87 89 78 85 91 85 86 75 69 85 60 87 80 85 71 83 70 81 82 61 53 69 59 34 45 7 16 7 10 11 22 14 9 13 13 24 30 14 40 13 16 14 28 17 28 16 18 38 46 16 41 61 55 80 84 78 77 81 77 83 83 75 68 72 67 73 60 78 80 80 71 83 70 73 79 61 52 63 58 34 45 12 0 11 10 8 1 2 8 9 18 2 2 12 0 9 0 5 0 0 0 9 3 0 1 5 1 0 0 1 0 4 3 0 0 1 0 2 1 1 1 1 0 0 3 1 1 0 2 3 0 1 1 16 0 4 0 1.074 1.069 1.079 1.079 1.063 1.069 1.074 1.070 1.065 1.062 1.079 1.048 1.070 1.071 1.064 1.070 1.079 1.063 1.063 1.066 1.059 1.065 1.065 1.089 1.048 1.067 1.071 1.064 2.5 2.5 2.5 2.5 3.5 2.5 2.5 1.0! 2.5 2.5 3.5 1.5 2.5 1.5 1.5 3.0 1.0 1.0 2.5 1.5 2.0 1.0! 1.5 2.0 1.5 1.5 - 1.5 0 0 1 3 0 0 0 0 0 0 0 0 1 0 0 1 2 0 1 0 0 0 0 1 0 0 0 0 1 0 4 0 3 4 1 0 3 0 1 0 0 0 0 0 0 1 1 0 0 0 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2.0 2.5 1.0 1.3 2.1 2.8 1.0 2.5 3.5 - 1.8 3.5 2.0 2.0 1.0 3.5 3.0 - 2.5 2.0 2.0 1.0 2.0 3.0 1.5 3.5 0.5 2.0 2.5 3.0 1.8 2.8 1.5 3.0 3.0 1.8 1.3 2.3 2.8 1.0 1.8 1.5 2.5 2.3 1.0 1.0 4.0 2.0 1.0 1.8 1.0 3.5 1.8 1.8 2.8 3.3 0.8 0.8 1.6 1.0 1.7 0.8 0.8 0.5 0.6 0.2 0.8 0.8 2.0 0.8 0.8 0.9 1.0 0.8 0.7 - 0.7 0.3 0.8 2.4 0.5 0.8 - 0.5 45 Table 8 MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS PRELIMINARY TRIAL, TABLESTOCK LINES MONTCALM RESEARCH FARM May 4 to September 7, 2010 (126 days) CWT/A PERCENT OF TOTAL1 PERCENT (%) CHIP TUBER QUALITY3 LINE 1991-563-18 MSU616-2PP MEAN HSD0.05 US#1 TOTAL US#1 Bs 40 16 60 84 58 17 258 268 144 104 336 276 As 40 16 OV PO SP GR SCORE2 HH VD IBS BC SCAB4 MAT5 BRUISE6 0 0 0 0 1.082 1.071 1.069 0.010 1.5 1.0 0 0 0 0 0 0 0 0 1.0 2.0 2.1 2.3 3.3 1.8 2.1 2.1 0.4 0.6 0.9 LBR Line(s) demonstrated foliar resistance to Late Blight (Phytopthora infestans ) in inoculated field trials at the MSU Muck Soils Research Farm. 1SIZE: B: < 2 in.; A: 2-3.25 in.; OV: > 3.25 in.; PO: Pickouts. 2CHIP SCORE: Snack Food Association Scale (Out of the field); Ratings: 1-5; 1: Excellent, 5: Poor. 3QUALITY: HH: Hollow Heart; BC: Brown Center; VD: Vascular Discoloration; IBS: Internal Brown Spot. Percent of 20 Oversize and/or A-size tubers cut. 4SCAB DISEASE RATING: MSU Scab Nursery; 0: No Infection; 1: Low Infection <5%; 3: Intermediate; 5: Highly Susceptible. 5MATURITY RATING: August 24, 2010; Ratings 1-5; 1: Early (vines completely dead); 5: Late (vigorous vine, some flowering). 6BRUISE: Simulated blackspot bruise test average number of spots per tuber. 46 Table 9 LINE Sorted by ascending 2010 Rating; A98289-1RUS Sieglinde MSS297-3 1991-563-18 AC00395-2RUS Goldrush Russet MSH228-6 MSJ126-9Y MSL007-B MSM037-3 MSN215-2P MSP270-1 MSQ035-3LBR MSR036-5LBR MSR102-3LBR MSR127-2 MSR131-2 MSR169-8Y MSR297-A MSS544-1R MST386-1P MSU320-2Y MSU383-1 MSU384-1 ND8229-3 Silverton Russet W2609-1R W2683-2RUS MSU200-5PP Pike A98134-2RUS MSJ147-1 MSK409-1 MSQ279-1 MST441-1 W8946-1RUS MSQ070-1LBR MSR061-1LBMR,PVYR MSR157-1Y MST285-2 MSU230-2Y A00188-3C A01124-3RUS MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS 2008-2010 SCAB DISEASE TRIAL SUMMARY SCAB NURSERY, MONTCALM CO., MI 3-YR* AVG. 2010 2010 2010 2009 2009 2009 2008 2008 2008 RATING WORST N RATING WORST N RATING WORST N - - 1.1 - - - - 1.0* 1.1 1.1 1.0* 1.3 0.9 1.3* 1.5 1.3 1.0 1.1 - 1.0 1.5 0.9 - - - - - 1.0 - - - 1.3 - 1.4 1.6 - - - 1.2 1.2 1.4 1.4* 1.4* 0.5 0.5 0.9 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.1 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.5 1.5 1.5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 4 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 2 2 2 2 2 2 2 8 2 2 2 2 2 2 2 2 2 2 1 2 2 - - 1.0 - - 1.0 1.3 1.3 1.0 1.3 0.8 1.5 2.0 1.3 0.8 1.0 - 1.0 1.7 0.8 - - - - - 1.3 - - - 1.5 - 1.7 1.6 - - - 1.3 1.1 1.5 1.5 - 1.3 - - - 1 - - 1 2 2 1 2 1 2 2 2 1 1 - 1 2 1 - - - - - 2 - - - 2 - 2 2 - - - 2 2 2 2 - 2 - - - 4 - - 4 4 4 3 4 4 4 4 4 4 4 - 4 3 4 - - - - - 4 - - - 8 - 3 4 - - - 3 4 4 4 - 3 - - - 1.5 - - - 1.0 1.1 - 1.8 1.0 - 1.5 1.5 1.1 1.3 - 1.0 1.8 1.0 - - - - - 0.8 - - - 1.4 - 1.4 2.0 - - - 1.0 1.3 1.5 - - - - - - 2 - - - 1 2 - 2 1 - 2 2 2 2 - 1 2 1 - - - - - 1 - - - 2 - 2 4 - - - 1 2 2 - - - - - - 1 - - - 3 4 - 4 4 - 3 3 4 4 - 2 3 4 - - - - - 4 - - - 15 - 4 3 - - - 4 4 4 - - - - 47 Table 9 LINE Sorted by ascending 2010 Rating; CO00188-4W CO95051-7W Kalkaska (MSJ036-A) MSM171-ALBR MSN148-A MSNDU030-1 MSQ341-BY MSR058-1 MSR605-11 MSS108-1 MSS737-1YLBR MST202-5 MST220-8 MST306-1 MST406-2RR MSU379-1 ND8307c-3 A01143-3C MSL228-1SPL MSN170-A MSQ440-2 MST424-3 MSU279-1 AF2291-10 Beacon Chipper CO99053-3RUS MSN230-1RY MSN251-1Y MSQ029-1LBR MSQ405-1PP MSQ432-2PP MSQ461-2PP MSR041-3 MSR159-02LBR MSR160-2Y MSR217-1R MSR605-5 MSS258-1 MSS514-1PP MSS576-05SPL MSS582-1SPL MSU161-1 MSU372-1Y MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS 2008-2010 SCAB DISEASE TRIAL SUMMARY SCAB NURSERY, MONTCALM CO., MI 3-YR* AVG. 2010 2010 2010 2009 2009 2009 2008 2008 2008 RATING WORST N RATING WORST N RATING WORST N 1.8* - 1.3 1.8 1.6 - - 1.3 - - 1.5 1.6* 1.8* 1.3* - - - 1.5* 2.0 - 1.3 1.5* - - 1.4 1.7 1.1* - 2.0 1.4* 1.8 1.4 - 1.7 - 1.9* - 2.0 1.4 2.0 2.0 - - 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.8 1.8 1.8 1.8 1.8 1.8 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 2 2 2 2 2 2 1 2 2 2 2 2 2 2 2.0 - 1.3 2.3 2.0 - - 1.3 - - 1.3 1.8 2.1 1.0 - - - 1.3 2.5 - 1.0 1.3 - - 1.3 1.5 0.3 - 2.0 0.8 1.8 0.8 - 1.5 - 1.8 - 2.0 1.5 2.0 1.6 - - 2 - 2 3 3 - - 2 - - 2 3 3 2 - - - 2 4 - 2 2 - - 2 3 1 - 2 1 3 1 - 2 - 3 - 3 3 3 3 - - 4 - 4 4 4 - - 4 - - 4 4 4 4 - - - 4 3 - 4 4 - - 4 4 4 - 4 4 4 4 - 4 - 4 - 4 4 4 4 - - - - 1.1 1.7 1.4 - - 1.3 - - 1.7 - - - - - - - 1.6 - 1.3 - - - 1.0 1.5 - - 2.0 - 1.5 1.5 - 1.5 - - - 2.0 0.8 - 2.4 - - - - 2 3 2 - - 2 - - 2 - - - - - - - 2 - 2 - - - 1 3 - - 2 - 2 2 - 2 - - - 2 1 - 3 - - - - 4 8 4 - - 4 - - 3 - - - - - - - 4 - 4 - - - 1 4 - - 4 - 2 4 - 3 - - - 1 4 - 4 - - 48 Table 9 LINE Sorted by ascending 2010 Rating; MSU500-2SPL MSU616-1PP MSU616-2PP MSU616-3P ND8555-8R NY139 Red Norland Russet Burbank W2310-3 W5767-1R MSQ130-4LBR MST437-1 Onaway MSL211-3 MSP515-2 Spunta MI Purple Sport III MSQ086-3LBR MSQ558-2RR NorValley Russet Norkotah CO00291-5R Missaukee MSL292-A MSN105-1LBMR MSQ134-5LBR MSQ425-4Y SPL MSR148-4 MSR214-2P MSR219-2R MSR605-02 MSR606-02 MSS206-2LBR MSU278-1 MSU613-1 Reba Spunta G2 CO99256-2R Snowden Atlantic CO02024-9W CO02321-4W MSL268-DLBR,PVYR MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS 2008-2010 SCAB DISEASE TRIAL SUMMARY SCAB NURSERY, MONTCALM CO., MI 3-YR* AVG. 2010 2010 2010 2009 2009 2009 2008 2008 2008 RATING WORST N RATING WORST N RATING WORST N - - - - - - - - - - 1.8 - 1.8 2.3* 2.0* 2.1* - - 2.1 1.7 - - - 2.5 2.1 2.1 2.2 - - 2.4 - - 2.1 - - 2.2 - 2.3* 2.6 2.7 - - 2.2 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.1 2.2 2.3 2.3 2.3 2.3 2.3 2.3 2.3 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.8 2.9 2.9 3.0 3.0 3.0 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 4 4 3 3 3 3 2 2 1 2 2 2 2 2 2 2 2 2 6 6 2 2 2 4 2 2 4 2 2 2 2 2 4 2 2 2 2 2 2 2 2 2 2 2 10 10 2 2 2 - - - - - - - - - - 1.8 - 1.6 2.4 1.8 - - 2.5 1.3 - 2.0 - - 2.3 2.0 1.9 2.3 - - 2.5 - - 2.1 - - 2.0 - 1.8 2.3 2.7 - - 2.5 - - - - - - - - - - 3 - 2 3 2 - - 4 2 - 3 - - 3 2 2 4 - - 3 - - 3 - - 3 - 3 3 3 - - 4 - - - - - - - - - - 4 - 8 4 4 - - 4 4 - 4 - - 4 4 4 4 - - 2 - - 4 - - 8 - 4 12 8 - - 4 - - - - - - - - - - 1.5 - 1.8 - - - - 1.5 1.6 - - - - 2.8 1.9 1.9 1.9 - - 2.3 - - 1.8 - - 2.0 - - 2.6 2.4 - - 1.1 - - - - - - - - - - 2 - 2 - - - - 2 2 - - - - 3 3 3 2 - - 3 - - 2 - - 3 - - 3 3 - - 2 - - - - - - - - - - 4 - 7 - - - - 4 4 - - - - 4 4 4 4 - - 4 - - 4 - - 8 - - 16 12 - - 4 49 Table 9 2008-2010 SCAB DISEASE TRIAL SUMMARY SCAB NURSERY, MONTCALM CO., MI MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS 2010 2010 2010 2009 2009 2009 2008 2008 2008 3-YR* AVG. RATING WORST N RATING WORST N RATING WORST N 2.7 - - - 2.3 - 2.0 2.6 - - - - - LINE Sorted by ascending 2010 Rating; MSM182-1LBR,PVYR MSM288-2Y MSNDU022-1 MSP459-5 MSQ176-5LBR MSR089-9Y MSR226-1RR MSS026-2Y MST191-2Y MSU088-1 ND8314-1R W2717-5 Jingshu 2 MSS070-B W5015-12 Jacqueline LeeLBR CO00197-3W Colorado Rose FL1879 Midnight MSR241-4RY MSR606-10 W2978-3 W6234-4RUS Zongshu 3 CO02033-W AC01151-5W MSM183-1 Red Pontiac H/LSD0.05 = SCAB DISEASE RATING: MSU Scab Nursery plot rating of 0-5; 0: No Infection; 1: Low Infection <5%, no pitted leisions; 3: Intermediate >20%, some pitted leisions (Susceptible, as commonly seen on Atlantic); 5: Highly Susceptible, >75% coverage and severe pitted leisions. LBR Line(s) demonstrated foliar resistance to Late Blight ( Phytopthora infestans ) in inoculated field trials at the MSU Muck Soils Research Farm. 2.1 - - - 2.0 - 2.0 2.2 - - - - - - - 3.3 - - 2.5 - 2.3 - - - - - - - - 0.9 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.3 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.8 3.8 4.0 4.5 2.3 2.9 - - - 1.8 - 1.0 2.5 - - - - - 2.0 - 2.5 3.1 - 2.0 2.3 1.8 - - - - - - - - 1.1 4 - - - 3 - 3 3 - - - - - - - 4 - - 11 - 4 - - - - - - - - 2.5* - 3.0 3.3* - 2.7 2.9* 2.5 - - - - - - - - 3 3 3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 4 5 3 - - - 2 - 2 3 - - - - - - - 4 - - 3 - 3 - - - - - - - - 4 - - - 3 - 2 3 - - - - - 3 - 3 4 - 3 4 3 - - - - - - - - 4 - - - 4 - 4 4 - - - - - 4 - 4 4 - 7 3 4 - - - - - - - - 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 50 Table 10 2010 LATE BLIGHT VARIETY TRIAL MUCK SOILS RESEARCH FARM MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS RAUDPC1 MEAN Female Male LINE RAUDPC1 MEAN J. Lee NY121 ND5084-3R Torridon MSJ317-1 J. Lee NY121 NY103 B0766-3 0.4 0.4 0.4 0.4 0.6 0.7 0.8 0.9 0.9 0.9 0.9 1.0 1.0 1.0 1.0 1.4 1.4 1.5 1.7 2.1 2.5 3.9 4.1 4.9 5.0 6.1 8.7 8.8 9.0 9.9 10.2 MSI152-A 10.6 Stirling 10.9 10.9 Spunta G2 11.8 MSI152-A 20.2 LINE Sorted by ascending RAUDPC value: Foliar Resistance Category (select lines): Torridon MCR150 MCR205 ND039036-2R LBR9 VSB16 (LBR8) Montanosa J138K6A22 MSR214-2P MSM183-1 Sherriff Kenya Baraka Monserrat MSL268-D Satina MSQ029-1 Stirling MSR160-2Y A9520-43 CO00291-5R Mnandi MSE149-5Y 82.4 MSQ405-1PP NY121 MSI152-A MSU279-1 MSR061-1 MSR036-5 MSE149-5Y 82.1 Gala MSR148-4 Sieglinde MSM182-1 MSR605-02 MSQ176-5 Tukey HSD0.05 1 Ratings indicate the average plot RAUDPC (Relative Area Under the Disease Progress Curve). 2 157 potato varieties and advanced breeding lines were tested in all. For brevity purposes, only selected varieties and breeding lines are listed. Phytopthora infestans isolate US-8 was inoculated on 8/3/2010. NOTE: US-22 was identified at the Muck Soils Research Farm. Planted as a randomized complete block design consisting of 3 replications of 4 hill plots on 6/7/2010. Foliar Susceptibility Category (select lines) 2 : Beacon Chipper MSR217-1R MST306-1 Silverton Russet MSR297-A MSQ134-5 A01124-3RUS A01143-3C ND8229-3RUS Midnight MSQ086-3 MSU245-2 Austrian Crescent MST191-2Y A98134-2RUS NY139 MSR041-3 MSS576-05SPL MSR605-05 NDU030-1 Russian Banana MSQ035-3 W2310-3 MSU307-3Y Red Norland ND8314-1R Russet Norkotah CO02321-4W MSR219-2R MSS026-2Y Onaway D Red Norland W2609-1R W2978-3 A98289-1RUS 43.5 43.8 44.3 44.3 44.4 44.7 44.7 45.1 45.5 45.5 45.6 46.0 46.2 46.4 46.9 47.9 48.6 48.6 49.3 49.5 49.9 50.4 51.3 52.2 52.3 53.0 53.0 53.5 54.5 55.0 56.3 57.4 58.1 62.9 64.7 B0718 Mainestay NY132 Torridon NY121 MegaChip MSL766-1 Liberator Saginaw Gold ND860-2 Saginaw Gold ND860-2 MSG147-3P MSJ319-1 NY121 Missaukee Missaukee Dakota Pearl MSJ126-9Y 51 Table 11 MICHIGAN STATE UNIVERSITY POTATO BREEDING and GENETICS 2010 BLACKSPOT BRUISE SUSCEPTIBILITY TEST SIMULATED BRUISE SAMPLES* NUMBER OF SPOTS PER TUBER ENTRY ADVANCED TRIAL MSQ279-1 MSP270-1 MSQ440-2 MSH228-6 MSQ086-3 MSJ126-9Y MSR061-1 MSJ147-1 FL1879 MSL007-B MSQ070-1 Kalkaska (J036-A) MSL292-A Beacon Chipper MSP515-2 Snowden MSP459-5 Atlantic RUSSET TRIAL A01124-3RUS Russet Norkotah-NCR MSS737-1Y MSR605-11 MSR605-05 Silverton Russet MSR606-10 W6234-4RUS MSR606-02 CO99053-3RUS A98134-2RUS MSN170-A Russet Norkotah-Sandyland Spunta G2 Goldrush A98289-1RUS AC00395-2RUS 0 21 20 20 17 17 14 11 12 12 10 11 8 8 7 7 9 6 4 25 23 22 20 19 19 17 17 8 16 16 15 16 15 15 16 13 1 4 5 5 7 7 8 13 10 9 11 5 7 5 8 8 5 6 5 1 2 5 6 5 8 7 5 8 7 8 6 8 6 5 9 2 1 1 2 1 3 4 3 6 6 9 6 6 5 7 7 1 1 1 1 1 2 2 3 2 4 2 2 3 4 5+ 1 2 2 5 2 2 1 1 3 4 3 3 2 4 4 2 2 1 PERCENT (%) BRUISE FREE AVERAGE SPOTS/TUBER 84 80 80 68 68 56 44 48 48 40 44 32 32 28 28 36 24 16 100 92 88 80 76 76 68 68 62 64 64 60 64 60 60 64 52 0.2 0.2 0.2 0.4 0.4 0.6 0.6 0.6 0.7 0.8 1.0 1.2 1.3 1.3 1.4 1.5 1.6 2.2 0.0 0.1 0.2 0.2 0.2 0.3 0.3 0.4 0.4 0.4 0.4 0.5 0.5 0.5 0.6 0.6 0.6 52 2010 BLACKSPOT BRUISE SUSCEPTIBILITY TEST SIMULATED BRUISE SAMPLES* NUMBER OF SPOTS PER TUBER ENTRY Spunta Russet Burbank-NCR MSR605-02 W8946-1RUS-NCR W2683-2RUS 0 13 12 8 8 1 1 8 9 6 3 2 NORTH CENTRAL REGIONAL TRIAL 6 Red Norland 9 W2609-1R W2978-3 9 13 MSQ176-5 7 Pontiac ND8307C-3 9 10 MSL211-3 5 ND8314-1R 7 ND8555-8R NorValley 9 7 MSM182-1 12 W2717-5 Atlantic 5 9 MSL268-D 3 W2310-3 4 ND8229-3RUS W5015-12 7 19 16 14 11 14 11 8 10 9 8 10 6 8 5 6 4 0 2 4 2 6 10 11 2 1 3 4 5 9 7 5 3 3 7 6 9 10 7 ADAPTATION TRIAL, CHIP-PROCESSING LINES MSS108-1 MSQ432-2PP MSR102-3 MSR159-02 MSR226-1RR MSS258-1 Pike MSS206-2 MSR131-2 MSR169-8Y MSR036-5 MSS026-2Y Missaukee MSR058-1 Snowden 18 16 16 12 15 12 11 8 9 11 9 7 5 7 5 6 8 6 12 7 9 10 12 9 7 8 8 8 7 10 1 1 3 1 2 2 3 4 5 3 4 3 7 6 4 3 2 2 3 5 1 2 1 1 2 3 3 4 3 3 4 6 1 2 1 2 3 3 5 4 3 4 4 2 3 1 1 1 1 1 1 2 3 1 4 1 1 2 1 1 5+ 1 1 3 1 1 2 1 1 2 1 PERCENT (%) BRUISE FREE AVERAGE SPOTS/TUBER 52 48 32 32 4 76 64 56 44 56 44 32 40 36 32 40 24 32 20 24 16 0 72 64 64 48 60 48 44 32 36 44 36 28 20 28 20 0.6 0.8 1.5 1.5 2.6 0.2 0.4 0.5 0.6 0.7 0.8 1.0 1.0 1.1 1.2 1.2 1.2 1.4 1.5 1.9 2.0 2.4 0.3 0.4 0.5 0.6 0.6 0.8 0.8 0.9 1.0 1.0 1.2 1.5 1.5 1.5 1.6 53 2010 BLACKSPOT BRUISE SUSCEPTIBILITY TEST SIMULATED BRUISE SAMPLES* NUMBER OF SPOTS PER TUBER ENTRY MSQ558-2RR Atlantic MSN148-A CO95051-7W MSQ035-3 MSK409-1 0 7 2 4 3 2 1 1 3 4 6 7 7 8 2 7 15 9 4 5 4 3 6 3 2 10 6 5 ADAPTATION TRIAL, TABLESTOCK LINES MSM288-2Y MSS544-1R MSN105-1 MSR157-1Y MSS576-05SPL MSQ461-2PP MSL228-1SPL MSQ341-BY MSS514-1PP MSS582-1SPL MSN215-2P MSQ134-5 J. Lee Onaway Reba MSQ425-4Y MSN230-1RY 23 22 6 19 17 16 16 17 14 15 14 16 8 9 5 5 3 2 3 1 4 7 8 5 4 9 7 7 4 12 10 7 8 8 1 1 1 4 3 2 3 4 4 5 3 11 7 6 PRELIMINARY TRIAL, CHIP-PROCESSING LINES MSR160-2Y MST202-5 A00188-3C MSU384-1 CO00188-4W MSU379-1 MST437-1 MSQ130-4 MST306-1 MSQ029-1 A01143-3C Pike MSU245-1 MSU245-2 25 13 12 21 20 20 18 17 15 14 16 13 16 13 1 4 5 4 5 7 5 9 5 10 3 9 1 2 2 2 3 1 5 2 1 1 1 2 5 4 1 1 1 1 5+ 1 2 5 4 1 1 2 1 5 2 2 4 1 PERCENT (%) BRUISE FREE AVERAGE SPOTS/TUBER 28 8 16 12 8 4 92 88 86 79 68 64 64 68 56 60 56 64 32 36 20 20 12 100 100 92 84 80 80 72 68 68 56 64 52 64 52 1.8 1.9 1.9 2.0 2.2 2.6 0.1 0.1 0.1 0.3 0.4 0.4 0.5 0.5 0.5 0.5 0.6 0.6 0.9 1.1 1.4 1.5 1.9 0.0 0.0 0.1 0.2 0.2 0.2 0.4 0.4 0.4 0.5 0.6 0.6 0.6 0.6 54 2010 BLACKSPOT BRUISE SUSCEPTIBILITY TEST SIMULATED BRUISE SAMPLES* NUMBER OF SPOTS PER TUBER ENTRY AC01151-5W CO00197-3W CO02024-9W MST441-1 MST220-8 NY139 NDU030-1 MSR148-4 CO02033-1W MST424-3 Snowden MSS297-3 MSU358-2 MSU088-1 CO02321-4W AF2291-10 MSU383-1 Atlantic MST191-2Y MSU246-1 MSR127-2 0 12 12 12 12 14 8 10 6 8 11 7 9 9 6 7 6 12 5 8 5 4 1 10 9 10 8 4 12 7 14 9 4 10 6 7 9 9 7 2 8 4 7 6 2 2 4 2 4 5 5 5 4 6 6 5 8 5 8 5 9 4 8 8 8 3 PRELIMINARY TRIAL, TABLESTOCK LINES MSU202-1P(1REP) MSR297-A 1991-563-18 MSQ405-1PP MST406-2RR MSU613-1 MSU616-2PP Colorado Rose CO00291-5R MSR217-1R MSR214-2P MSU279-1 MSU500-2SPL CO99256-2R MSR241-4RY MSU161-1 MSU200-5PP 20 19 14 15 11 8 6 13 13 11 12 12 5 11 10 12 13 5 5 7 8 5 3 6 8 7 11 8 7 6 9 11 7 5 1 1 2 2 1 4 5 2 4 6 2 4 3 5 6 4 5+ 1 1 1 1 2 3 1 2 3 4 1 1 3 3 1 1 1 1 3 2 4 3 1 3 2 3 1 3 3 3 2 5 1 1 1 1 1 1 1 PERCENT (%) BRUISE FREE AVERAGE SPOTS/TUBER 48 48 48 48 56 32 40 24 32 44 28 36 36 24 28 24 48 20 32 20 16 80 76 64 60 61 67 46 52 52 44 48 48 38 44 40 48 52 0.7 0.7 0.7 0.8 0.8 0.9 1.0 1.0 1.1 1.1 1.2 1.2 1.2 1.2 1.3 1.4 1.4 1.5 1.5 1.6 2.3 0.2 0.3 0.4 0.5 0.5 0.5 0.6 0.6 0.7 0.7 0.8 0.8 0.8 0.8 0.8 0.8 0.8 55 2010 BLACKSPOT BRUISE SUSCEPTIBILITY TEST SIMULATED BRUISE SAMPLES* NUMBER OF SPOTS PER TUBER 0 8 7 10 12 14 9 11 4 5 3 3 1 6 16 10 9 4 8 5 8 6 8 4 2 3 1 4 2 3 6 6 8 8 5 8 3 1 1 1 1 4 2 3 4 4 5 4 4 5+ 1 1 1 3 1 1 3 3 PERCENT (%) BRUISE FREE AVERAGE SPOTS/TUBER 44 28 40 48 56 36 44 16 20 12 12 0.8 0.8 0.8 0.8 0.9 1.0 1.0 1.6 1.7 2.0 2.4 ENTRY MSU616-1PP Midnight MSNDU045-1 MSU320-2Y Zongshu 3 MSNDU022-1 MST285-2 MST386-1P Onaway W5767-1R Jingshu 2 56 2010 BLACKSPOT BRUISE SUSCEPTIBILITY TEST SIMULATED BRUISE SAMPLES* NUMBER OF SPOTS PER TUBER 2 1 0 1 ENTRY USPB/SFA TRIAL CHECK SAMPLES (Not bruised) NY138 W2978 MSJ126-9Y W2717-5 CO97043-14W NY139 CO97065-7W Snowden AF2291-10 MSL292-A W2310-3 W5015-12 Atlantic 23 22 20 15 14 14 13 14 10 12 8 11 2 1 3 5 10 10 9 9 8 13 6 10 5 12 1 1 3 2 2 3 5 5 4 3 4 5+ 1 1 2 2 3 5 2 1 1 1 PERCENT (%) BRUISE FREE AVERAGE SPOTS/TUBER 92 88 80 60 56 56 52 56 40 48 32 44 8 0.1 0.1 0.2 0.4 0.5 0.6 0.6 0.6 0.7 1.0 1.0 1.1 1.8 USPB/SFA TRIAL BRUISE SAMPLES MSJ126-9Y NY138 W2978 CO97043-14W NY139 MSL292-A W2717-5 CO97065-7W AF2291-10 W2310-3 Atlantic Snowden W5015-12 * Twenty or twenty-five A-size tuber samples were collected at harvest, held at 50 F at least 12 hours, and placed in a six-sided plywood drum and rotated ten times to produce simulated bruising. Samples were abrasive-peeled and scored 10/18/2010. The table is presented in ascending order of average number of spots per tuber. 0.4 0.4 0.8 0.9 1.0 1.1 1.3 1.6 1.9 2.0 2.2 2.6 3.0 60 68 48 40 36 40 40 20 8 16 12 12 4 9 6 8 9 10 9 5 5 10 9 7 2 4 15 17 12 10 9 10 10 5 2 4 3 3 1 1 1 3 4 5 3 5 11 5 4 7 7 5 1 3 4 5 3 2 8 6 2 2 3 1 3 1 1 2 1 2 2 1 1 3 3 4 6 57 Funding: Federal Grant, MPIC and USPB/SFA 2010 On-Farm Potato Variety Trials Chris Long, Dr. Dave Douches, Dr. Doo-Hong Min (Upper Peninsula) and Chris Kapp (Upper Peninsula) Introduction On-farm potato variety trials were conducted with 13 growers in 2010 at a total of 18 locations. Eleven of the locations evaluated processing entries and seven evaluated fresh market entries. The processing cooperators were Crooks Farms, Inc. (Montcalm), Walther Farms, Inc. (St. Joseph), Lennard Ag. Co. (Branch), County Line Potato Farms, Inc. (Allegan), Main Farms (Montcalm), Michigan State University (MSU), Montcalm Research Farm (Montcalm) and Thorlund Brothers (Montcalm). The United States Potato Board/Snack Food Association (USPB / SFA) chip trial was at Sandyland Farms, LLC (Mecosta). Fresh market trial cooperators were Crawford Farms, Inc. (Montcalm), Elmaple Farms (Kalkaska), R & E Farms (Presque Isle), Horkey Bros. (Monroe), T.J.J. VanDamme Farms (Delta), Sandyland Farms, LLC (Newaygo) and Walther Farms, Inc. (Branch). Procedure There were six types of processing trials conducted this year. The first type contained 13 entries which were compared with the check varieties Snowden, Pike and FL1879. This trial type was conducted at Main Farms, Lennard Ag. Co. and County Line Farms. Varieties in these trials were planted in 100’ strip plots. Seed spacing in each trial was grower dependent, but in general ranged from 9.5 to 11 inches. The second type of processing trial, referred to as a “Select” trial, contained six lines which were compared to the variety in the field. In these trials, each variety was planted in a 15’ row plot. Seed spacing and row width were 10” and 34”, respectively. These trials were conducted on Crooks Farms, Inc. (Montcalm). The third was a processing variety trial where each plot consisted of three 34” wide rows which were 15’ long. Only the center row was harvested for the yield evaluation. This trial was conducted at Walther Farms, Inc. (St. Joseph). At Walther’s, 21 varieties were compared to the check varieties Snowden, Pike and FL1879. The plots were planted at 10” in-row spacing. The fourth type was the Box Bin trial at the Montcalm Research Farm in Montcalm County, MI. This trial contained 20 varieties compared against the check variety Snowden. Each of the 21 varieties were planted in a single 34” wide row, 600’ long with 10” in-row seed spacing. A single 23’ yield check was taken to evaluate each clone. The fifth type of chip trial consisted of large multiple acreage blocks of three newly commercialized or soon to be commercialized varieties. Agronomic and production practices for these varieties were based on each individual grower’s production system. The varieties and growers were: Thorlund Brothers (Montcalm), MSJ126-9Y; Lennard Ag. Co. (Branch), NY139 (Lamoka); Walther Farms (St. Joseph), W2133-1 (Nicolet). 58 The USPB / SFA chip trial was the 6th chip processing trial type. For procedural details on this trial, reference the 2010 annual report published by the United States Potato Board. Within the fresh market trials, there were 26 entries evaluated. There were 7 to 22 lines planted at each of the following locations: Branch, Delta, Kalkaska, Monroe, Montcalm and Presque Isle counties. The varieties in each trial ranged from mostly round white varieties to mostly russet varieties. These varieties were generally planted in 100’ strip plots. A single 23’ yield check was taken to evaluate each clone in these strip trials. Seed spacing varied from 8 to 12 inches depending upon grower production practices and variety. At Walther Farms, Inc. (Branch), three row plots were evaluated. The plots were 15’ long by 34” wide and seed spacing was 12”. Only the center row was harvested and evaluated. The second freshpack trial type was the Russet Select Trial. The select russet trials were planted at three locations (Elmaple Farm (Kalkaska), Montcalm Research Farm (Montcalm) and Walther Farms, (St. Joseph)). Each russet variety was planted in one three row plot, that was thirty feet long with 34” wide rows and 11-12” in- row spacing. A yield determination was made on 23 feet of the center row. Each select trial varied in the number of varieties tested. The third type of freshpack trial was the small block plantings done at Horkey Bros. (Monroe) and Sandyland Farms, LLC (Newaygo). In each of these trials 2-3 varieties were planted in 4-8 row blocks 600- 1200’ in length. CO99053-3Rus was compared to Russet Norkotah at Sandyland in Newaygo Co. and MSL211-3, MSL268-D and MSQ176-5 were planted in Horkey’s in Monroe Co. A single 23’ plot was harvested in each of these plots to make a yield and quality determination. Results A. Processing Variety Trial Results A description of the processing varieties, their pedigree and scab ratings are listed in Table 1. The overall averages of the eight locations from Allegan, Branch, Mecosta, Montcalm and St. Joseph counties are shown in Table 2. A00188-3C; is an Aberdeen Idaho chip processing selection with above average yield and good long term chip quality from storage. In 2010, it had a 432 cwt./A US#1 yield with a 1.082 average specific gravity (Table 2). The overall size profile of the variety was small, but exhibited some common scab tolerance and a mid- season maturity. A01143-3C; is an Aberdeen Idaho chip processing selection with very strong yield potential and good long term chip quality from storage. In 2010, it had a 445 cwt./A US#1 yield with a 1.079 average specific gravity (Table 2). The overall size profile of the variety was smaller with 8 percent “B” size tubers and 83 percent Processing Variety Highlights 59 “A’s”. This variety exhibits some common scab tolerance, but appears to have a very late vine maturity. AF2291-10; this selection has been developed at the University of Maine. This variety appears to chip process well from out of the field and has early to mid- season storage. It’s yield potential is good, producing 444 cwt./A US#1 in 2010 (Table 2). The average specific gravity of this line was 1.083. Four hollow heart were observed in 40 cut tubers. The overall tuber type of this variety is not very uniform. This line has some common scab tolerance (Table 1). CO00188-4W; this selection is from the University of Colorado. It has a below average yield (Table 1), but has some common scab tolerance and late season chip quality and storability. MSH228-6; This Michigan State University selection continues to have an above average yield of US#1 size tubers (Table 2) and good common scab resistance (Table 1). This variety over four years of on-farm trialing has a 357 cwt./A US#1 yield. Some internal vascular discoloration has been noted over the years in finished chips from storage. MSJ126-9Y; This MSU selection was only at one location in 2010. Yield potential for this variety appears to be average, but it maintains a very uniform round tuber type. The four year yield average for this line is 334 cwt./A US#1. This variety is common scab resistant (Table 1). MSJ126-9Y has a good chip quality until March or April in storage. MSL007-B; is an MSU selection with a heavy netted skin and common scab resistance (Table 1). In 2010, it yielded above average at 392 cwt./A US#1 (Table 2). Chip quality appears to be good from mid-season storage. MSL292-A; is an Michigan State University developed variety. In 2010, MSL292- A had an average yield at 408 cwt/A US#1 (Table 2). This variety had 90% marketable yield and a slightly below average specific gravity at 1.076. Raw internal tuber quality was good. Pitted scab was noted in some plots. MSL292-A exhibited excellent chip quality out of the field and from storage in 2010 and early 2011. MSQ070-1; is a MSU clone with common scab and late blight resistance. In 2010 on-farm trials, this variety yielded only 278 cwt/A US#1 with a 1.080 specific gravity. There was 11% hollow heart reported across seven trial locations (Table 2). This variety had a vine maturity that was later than Snowden. Tuber type was very uniformly round and chip quality was good from mid to late season storage. This variety appeared to set well and could benefit from a slightly wider in-row seed spacing of 11 inches. MSR061-1; is an MSU developed variety with common scab tolerance, resistance to PVY and foliar late blight resistance (Table 1). This variety is a below average yielding line with an average specific gravity (Table 2). 60 NY139 (Lamoka); this is a Cornell, New York developed clone. This variety continues to exhibit a strong yield and good size profile. In the 2010 processing potato variety trials, NY139 yielded 378 cwt/A US#1 over eight locations with a 92% marketable yield average (Table 2). The specific gravity of this clone was above the trial average at 1.079. One hollow heart was noted in 100 cut tubers. NY139 also performed very well in the 2010 USPB/SFA trial (Table 3). This clone yielded 428 cwt/A US#1 with a 91% marketable yield. The specific gravity was two points above the trial average at 1.076. Raw tuber internal quality was good. Vine maturity for this variety appeared to be medium-late to late. W2133-1 (Nicolet); this clone was developed at the University of Wisconsin and has excellent mid-season chip quality. It appeared to exhibit variable yield potential, but performed most consistently in environments where the growing season is longer. The variety does appear to have a late vine maturity that could be classified as later than Snowden. In 2010, W2133-1, when averaged across two southern Michigan locations, yielded 496 cwt/A US#1 with no hollow heart being observed (Table 2). The size profile and the specific gravity were above the trial averages. This variety was susceptible to common scab. W5015-12; is a University of Wisconsin variety with strong yield potential. In 2010 it yielded 459 cwt./A US#1 with a 1.081 specific gravity (Table 2). Fifteen percent hollow heart was observed in this variety when averaged over 8 locations. Pitted and surface scab susceptibility was also noted. Chip quality from mid-season storage appears to be good. B. USPB / SFA Chip Trial Results The Michigan location of the USPB / SFA chip trial was on Sandyland Farms, LLC in Mecosta County in 2010. Table 3 shows the yield, size distribution and specific gravity of the entries when compared with Atlantic and Snowden. Table 4 shows the at harvest raw tuber quality results. Table 5 shows the out of the field chip quality evaluations from samples processed and scored by Herr Foods, Inc., Nottingham, PA and Table 6 provides the blackspot bruise susceptibility of each entry. Tables 7A and 7B provide a pre-harvest panel for each of the 13 varieties in the trial. These two tables compare tuber specific gravity, percent glucose and sucrose ratings taken on two different dates; August 24th, 2010 and September 7th, 2010 for each variety. USPB / SFA Chip Trial Highlights AF2291-10, W5015-12 and Snowden topped the yield chart in 2010 followed by MSL292-A, NY138, Atlantic and NY139 (Table 3). AF2291-10 and MSL292-A had a large percentage of recorded oversize tubers (Table 3). The MSL292-A, NY138, W2978-3 and MSJ126-9Y and CO97043-14W had very low specific gravities. The varieties in the 2010 trial that displayed the greatest potential for commercialization were AF2291-10, W5015-12 and NY139. Yield potential and specific gravity were good for AF2291-10 (Table 3). This clone has a full season 61 maturity and good early to mid–season chip quality. AF2291-10 appeared to have a slight susceptibility to black spot bruise (Table 6), but some tolerance to common scab. Table 5 shows some of the other varieties that did not have the best all- around agronomic performance, but had great chip quality, such as MSL292-A and W2717-5. C. Fresh Market and Variety Trial Results A description of the freshpack varieties, their pedigree and scab ratings are listed in Table 8. Table 9 shows the overall average of seven locations: Branch, Delta, Kalkaska, Monroe, Montcalm, Newaygo and Presque Isle counties. Fresh Market Variety Highlights Three round whites and three russet lines are worthy of mention from the 2010 variety trials. They are MSL211-3, MSL268-D and MSQ176-5 (the round whites), and the russets, A0008-1TERus, A01124-3Rus and CO99053-3Rus. MSL211-3; this Michigan State University variety has moderate foliar late blight resistance and slight common scab tolerance (Table 8). In the 2010 freshpack variety trials, this clone had a 369 cwt./A US#1 yield with a 1.069 specific gravity (Table 9). There were no hollow heart in 40 cut tubers and a trace of vascular discoloration was observed. The skin type of this variety was smooth and bright and the tubers were uniform in shape. MSL268-D; this variety has nice tuber type with foliar late blight resistance. In 2010, MSL268-D yielded 393 cwt/A US#1 with a medium vine maturity (Table 9). This variety has a four year US#1 yield average of 385 cwt./A. The total yield of this variety was reported as 465 cwt/A. The percentage of “B” sized tubers and the specific gravity was higher than desired. This variety was also common scab susceptible. MSQ176-5; this MSU clone has foliar late blight resistance, but appears to have some common scab susceptibility (Table 8). The 2010 yield trial data showed this variety having a 442 cwt/A US#1 yield which represents 89% of the total yield reported. Thirty-three percent of this marketable yield was oversize (Table 9). This variety averaged a 1.063 specific gravity, a medium maturity and two hollow heart in forty tubers cut. The tubers were generally bright skinned and uniformly round in appearance. A0008-1TERus; this is a USDA Aberdeen, ID developed variety. In 2008 this variety was selected in Michigan for superior tuber type and acceptable yield. In 2010, in one southern location, this variety did not perform exceptionally well. When tested in Branch Co. it only yielded 209 cwt/A US#1 with 12 percent oversize (Table 9). The specific gravity was 1.063 with 6 of 10 cut tubers exhibiting hollow heart. Vine maturity was early. This variety exhibited strong common scab resistance. This variety needs to be observed once again to clarify the conflicting results observed from the 2008 and 2010 growing seasons. 62 A01124-3Rus; this University of Idaho selection had a 322 cwt/A US#1 yield, an average specific gravity of 1.072 and acceptable internal quality (Table 9). The tuber appearance was long and blocky with a nice russeted skin. Vine maturity was medium. This was the most promising new russet selection evaluated in 2010. CO99053-3Rus; this Colorado State selection has good yield potential and tuber type. In 2010, it yielded 368 cwt/A US#1 with 23 percent oversize. The average specific gravity for this variety was 1.075 (Table 9). The clone had 8 hollow heart in fifty cut tubers. The vine maturity appeared to be late. The tubers exhibited a uniform, medium russet skin. The variety appeared to be common scab tolerant, but exhibited a trace of alligator hide. 63 2010 MSU Processing Potato Variety Trials Characteristics High yield, early maturing, high incidence of internal defects, check variety, high specific gravity *Scab rating based on 0-5 scale; 0 = most resistant and 5 = most susceptible. **2009 data Entry Atlantic Pedigree Wauseon X B5141-6 (Lenape) Pike (NYE55-35) Snowden (W855) A00188-3C A01143-3C AF2291-10 CO00188-4W Allegany X Atlantic B5141-6 X Wischip A91790-13 X Dakota Pearl COA95070-8 X Chipeta SA8211-6 X EB8109-1 A90490-1W X BC0894-2W CO00197-3W A91790-13W X NDTX4930-5W CO95051-7W AC88456-6W X BC0894-2W CO97043-14W CO97065-7W FL1879 AC91817-5 X AC87340-2 AC92513-3 X Chipeta Snowden X FL1207 MSH228-6 MSC127-3 X OP MSJ126-9Y Penta X OP MSL007-B MSA105-1 X MSG227-2 2010 Scab Rating* 2.9 1.1 2.9 1.5 1.8 2.0 1.5 3.5 1.5 3.0** 2.0** 3.5 1.0 1.0 1.0 Average yield, early to mid-season maturity, small tuber size profile, early storage check variety, some internal defects, medium specific gravity High yield, late maturity, mid-season storage check variety, reconditions well in storage, medium to high specific gravity High U.S. No. 1 yield, scaly buff skin, high specific gravity High yielding, scaly buff chipper; smaller tuber size Early blight resistant clone with good chipping quality, medium-late vine maturity, round to oblong, white netted tubers, specific gravity similar to Atlantic Medium yield potential. small tuber size, minimal grade defects, medium-early maturity, high specific gravity, some ability to recondition out of 40º F Medium yield potential, small size profile, minimal grade defects, early maturity, medium-high specific gravity, some ability to recondition out of 40º F Low – average yield, medium to late maturity, high percent of US#1 tubers, low internal defects, medium specific gravity, vine rot is a concern Average yield, medium maturity, white skin, oblong tuber type, medium specific gravity Average yield, early maturity, white skin, round tuber type, medium specific gravity High yield, late maturity, large tuber type, late season storage, medium specific gravity, check variety Average yield, mid-late season maturity, blocky flat tuber type, shallow eyes, medium specific gravity Medium yield, cold chipper from 45º F, uniform A-size tubers, attractive appearance, good internal quality, long term storage potential, medium specific gravity Average yield, early to mid-season maturity, uniform tuber type, medium specific gravity, scab resistant 64 Characteristics Above average yield, scab susceptible, late blight susceptible, medium-high specific gravity, long storage potential Below average yield, uniform round type, netted skin, good chip quality from early to mid-season storage, average specific gravity Bright chips, low incidence of defects, medium specific gravity Above average yield, large tuber size, medium late maturity, below average specific gravity Average yield potential, low specific gravity, uniform round tuber type Round tuber type, late maturity, scab and late blight resistant, high specific gravity, strong vine and roots High yield, large round tubers, good internal qualities Average yield, round tuber type with netted skin, low sugars, PVY resistant, moderate late blight resistance Below average yield, very late maturity, uniform tuber type, foliar late blight resistance to US-8 High yield, large uniform round tuber type, below average specific gravity, great chip High yield, mid-late season maturity, medium specific gravity, oval to oblong quality tuber type Entry MSL292-A Pedigree Snowden X MSH098-2 2010 Scab Rating* 2.5 MSP270-1 MSNT-1 X MSG227-2 1.0 MSP459-5 Marcy X NY121 MSP515-2 Marcy X Missaukee MSQ035-3 MSQ070-1 MSQ279-1 MSG227-2 X Missaukee MSK061-4 X Missaukee Boulder X Pike MSR061-1 W1201 X NY121 MSR102-3 W1773-7 X Missaukee NY138 (Waneta) NY 139 (Lamoka) W2133-1 (Nicolet) W2310-3 (Tundra) Marcy X NY115 NY120 X NY115 Snowden X S440 Pike X S440 W2717-5 S440 X ND2828-15 W2978-3 Monticello X Dakota Pearl W5015-12 Brodick X W1355-1 3.0 2.3 1.0 1.3 1.3 1.3 1.0 - 2.0 1.8** 2.0 3.0 3.5 3.0 Medium to high yield, mid to late maturity, good internal quality, nice tuber type, 47º F cold chipper, medium specific gravity Average yield potential, high specific gravity, smaller size profile, good chip quality from storage Round tuber type, medium yield, medium maturity, medium specific gravity, moderate scab susceptibility Above average yield potential, early bulking, medium early vine maturity, scab susceptible High tuber set and yield, medium-late vine maturity, uniform size tubers, tubers tend toward flat shape, very flat in some environments *Scab rating based on 0-5 scale; 0 = most resistant and 5 = most susceptible. **2009 data 65 NUMBER OF LOCATIONS 2 8 2 4 1 2 1 6 2 5 8 5 3 5 8 1 8 LINE W2133-1 W5015-12 A01143-3C FL1879 NY138 AF2291-10 Atlantic Snowden A00188-3C MSP515-2 MSL292-A MSL007-B W2978-3 MSH228-6 NY139 CO97065-7W W2310-3 CWT/A US#1 TOTAL US#1 496 459 445 444 444 444 443 433 432 414 408 392 391 384 378 344 341 551 531 547 458 471 507 472 472 518 439 453 425 446 405 407 377 407 90 86 83 97 94 88 94 89 82 95 90 91 87 94 93 91 84 Bs 8 12 8 2 6 8 6 10 16 5 10 9 11 5 6 8 11 As 87 81 83 89 82 76 82 83 82 83 85 88 83 86 87 81 82 3 5 0 8 12 12 12 6 0 12 5 3 4 8 6 10 2 2 2 9 1 0 4 0 1 2 0 0 0 2 1 1 1 5 1.089 1.081 1.079 1.075 1.071 1.083 1.082 1.077 1.082 1.072 1.076 1.074 1.071 1.076 1.079 1.070 1.080 2.0 1.3 1.3 1.8 1.0 1.3 1.5 1.3 1.3 1.3 1.1 1.1 1.3 1.3 1.1 1.0 1.3 0 5 15 17 0 14 1 4 8 0 3 5 11 3 11 21 0 2 2 2 1 1 1 9 2 7 6 15 6 7 12 13 1 7 0 7 3 0 0 0 2 0 0 2 1 1 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 2 20 100 20 40 30 40 30 80 20 50 100 50 50 50 100 30 100 3.8 2.9 3.0 2.9 3.0 2.3 3.0 3.1 3.3 2.6 3.3 2.0 2.7 3.3 2.9 3.5 3.2 3.5 3.3 3.8 2.6 3.0 3.0 3.5 3.1 2.5 3.8 2.4 2.8 2.2 2.9 2.6 1.5 2.9 2010 Processing Potato Variety Trial Overall Average - Eight Locations Allegan, Branch, Mecosta, Montcalm, St. Joseph Counties PERCENT OF TOTAL1 OV PO TUBER QUALITY2 SP GR SCORE3 HH VD IBS BC CHIP TOTAL CUT VINE VIGOR4 MATURITY5 VINE COMMENTS tr pitted scab pitted and surface scab sl surface scab CHIP COMMENTS severe SED 4-YR AVG US#1 CWT/A 490*** sl SED tr SED tr VD 473** 335** 464 444* not uniform type, tr points sl SED, some HH 444* surface and pitted scab SED, VD 443* pitted scab tr of severe SED 420 small uniform tuber type sl surface and pitted scab sl SED severe VD pitted and surface scab, uniform type tr SED small overall size, heavy dark net, sl pitted and surface scab surface and pitted scab surface scab tr VD SED SED sl surface scab, pointed pickouts tr SED surface and pitted scab misshappen tubers in pickouts, surface and pitted scab tr SED 330** 414* 424*** 351*** 391* 357 412*** 336** 299** 66 NUMBER OF LOCATIONS 4 2 5 6 2 1 6 7 5 5 1 5 1 2 LINE US#1 TOTAL US#1 MSQ035-3 CO00188-4W Pike MSQ279-1 CO00197-3W MSJ126-9Y W2717-5 MSQ070-1 MSR102-3 MSR061-1 CO97043-14W MSP459-5 MSP270-1 CO95051-7W 329 317 317 316 298 285 279 278 273 271 265 264 252 174 MEAN 355 370 425 356 351 381 336 342 334 302 314 305 334 304 276 407 85 71 89 90 71 84 82 82 90 85 87 77 83 61 86 Bs 9 29 9 5 26 16 13 13 6 14 13 23 17 30 As 81 71 83 81 71 81 80 81 81 85 80 77 80 61 1SIZE Bs: < 1 7/8" 2TUBER QUALITY (number of tubers per total cut) HH: Hollow Heart 3CHIP COLOR SCORE - Snack Food Association Scale (Out of the field) 4VINE VIGOR RATING Date Taken: N/A As: 1 7/8" - 3.25" VD: Vascular Discoloration OV: > 3.25" IBS: Internal Brown Spot PO: Pickouts BC: Brown Center Ratings: 1 - 5 1: Excellent 5: Poor Ratings: 1 - 5 1: Slow Emergence 5: Early Emergence (vigorous vine, some flowering) 5VINE MATURITY RATING Date Taken: N/A Ratings: 1 - 5 1: Early (vines completely dead) 5: Late (vigorous vine, some flowering) CWT/A PERCENT OF TOTAL1 OV PO TUBER QUALITY2 SP GR SCORE3 HH VD IBS BC CHIP TOTAL CUT VINE VIGOR4 MATURITY5 VINE COMMENTS CHIP COMMENTS 4 0 6 9 0 3 2 1 9 0 7 0 3 0 6 0 2 5 3 0 6 5 4 1 0 0 0 9 1.063 1.076 1.078 1.070 1.072 1.065 1.082 1.080 1.073 1.076 1.065 1.079 1.074 1.074 1.076 1.6 1.0 1.0 1.5 1.0 1.0 1.0 1.2 2.0 1.5 1.0 1.3 1.0 1.0 0 0 4 2 1 0 8 8 0 3 0 3 0 1 3 2 8 1 3 3 20 10 7 1 7 10 1 2 0 0 1 8 0 0 1 8 1 2 0 0 1 1 0 0 0 0 0 0 2 2 0 1 0 0 0 0 40 20 50 60 20 30 80 70 50 50 30 50 10 20 2.5 3.3 3.1 2.8 3.0 2.5 3.4 2.4 2.5 2.6 3.0 3.1 1.0 2.3 2.4 2.3 2.3 3.5 3.5 2.5 2.8 3.7 4.2 2.6 3.0 2.3 3.5 3.5 4-YR AVG US#1 CWT/A 329* 335** gc in pickouts, sl surface and pitted scab SED small uniform tuber type heat necrosis in two tubers tr heat necrosis 357 tr surface scab, gc and misshapen pickouts SED small tuber yield uniform type tr SED, VD pitted scab, gc in pickouts, severe VD SED sl surface scab, nice round tuber type, tr sticky stolons sl SED sicky stolen, surface scab SED misshapen pickouts, nice netted type, tr pitted scab sl SED surface and pitted scab small size profile, tr surface scab SED, VD netted skin, uniform type growth cracks, small tuber size SED tr = trace, sl = slight, N/A = not applicable SED = stem end defect, gc = growth crack 385** 373** 334 273** 354** 273* 275** 301** 288** 252* 271 *One-Year Average * *Two-Year Average * * *Three-Year Average 67 Table 3. Yield ,Size Distribution*, Specific Gravity Entry AF2291-10 W5015-12 Snowden MSL292-A NY138 Atlantic NY139 W2310-3 W2978-3 CO97065-7W MSJ126-9Y CO97043-14W W2717-5 MEAN Yield (cwt/A) US#1 TOTAL 506 498 463 457 444 443 428 418 392 344 285 265 258 400 565 565 510 490 471 472 469 479 434 377 336 305 300 444 US#1 90 89 90 93 94 94 91 87 91 91 84 87 86 90 Percent Size Distribution 74 78 82 79 82 82 80 78 82 81 81 80 84 80 16 11 8 14 12 12 11 9 9 10 3 7 2 10 Specific Small Mid-Size Large Culls Gravity 1.081 1.080 1.077 1.071 1.071 1.082 1.076 1.082 1.064 1.070 1.065 1.065 1.080 1.074 6 0 0 0 0 0 1 7 0 1 0 0 1 1.2 4 11 10 7 6 6 8 6 9 8 16 13 13 9 *small <1 7/8"; mid-size 1 7/8"-3 1/4"; large >3 1/4" Table 4. At-Harvest Tuber Quality. Sandyland Farms, Howard City, Michigan. Internal Defects1 Entry AF2291-10 W5015-12 Snowden MSL292-A NY138 Atlantic NY139 W2310-3 W2978-3 CO97065-7W MSJ126-9Y CO97043-14W W2717-5 HH 2 3 1 0 1 8 0 0 0 9 0 0 3 VD 5 5 7 5 5 3 2 3 2 1 3 7 7 IBS 0 6 0 0 0 2 0 0 0 0 0 0 0 BC 0 0 0 0 0 0 0 1 0 1 0 0 0 Total Cut 30 30 30 30 30 30 30 30 30 30 30 30 30 1Internal Defects. HH = hollow heart, VD = vascular discoloration, IBS = internal brown spot, BC = brown center. 68 Table 5. 2010 Post-Harvest Chip Quality1. Entry AF2291-10 W5015-12 Snowden MSL292-A NY138 Atlantic NY139 W2310-3 W2978-3 CO97065-7W MSJ126-9Y CO97043-14W W2717-5 Agtron SFA2 Specific Color Color Gravity 62.4 1.075 62.0 1.077 63.5 1.076 67.3 1.071 65.4 1.070 62.9 1.080 62.0 1.076 64.5 1.082 64.2 1.064 61.0 1.066 65.7 1.066 63.5 1.065 60.3 1.078 3 3 2 2 3 4 2 3 2 3 2 3 3 Percent Chip Defects3 Internal External Total 60.1 32.3 26.8 15.8 40.4 53.3 38.0 36.6 52.1 29.0 31.4 31.4 30.1 56.1 18.4 21.9 9.1 37.0 47.9 26.6 31.4 21.5 18.2 24.8 20.9 22.4 4.0 13.9 4.9 6.7 3.4 5.4 11.4 5.2 30.6 10.8 6.6 10.5 7.7 1 Samples collected at harvest October 8th and processed by Herr Foods, Inc., Nottingham, PA on October 11, 2010 (3 days). Chip defects are included in Agtron and SFA samples. 2 SFA Color: 1 = lightest, 5 = darkest 3 Percent Chip Defects are a percentage by weight of the total sample; comprised of undesirable color, greening, internal defects and external defects. Table 6. Black Spot Bruise Test A. Check Samples1 B. Simulated Bruise Samples2 Percent Average Total Bruise Bruises Per Tuber Percent Average Total Bruise Bruises Per Free Tuber Entry AF2291-10 W5015-12 Snowden MSL292-A NY138 Atlantic NY139 W2310-3 W2978-3 CO97065-7W MSJ126-9Y CO97043-14W W2717-5 # of Bruises Per Tuber 0 1 2 3 4 5 Tubers 10 13 2 11 5 5 3 1 14 8 2 1 12 6 3 2 2 23 1 1 2 12 4 5 1 1 14 9 1 1 8 10 5 2 22 3 13 9 3 20 5 14 10 1 15 10 25 25 25 25 25 25 25 25 25 25 25 25 25 Free 40 44 56 48 92 8 56 32 88 52 80 56 60 0.7 1.1 0.6 1.0 0.1 1.8 0.6 1.0 0.1 0.6 0.2 0.5 0.4 # of Bruises Per Tuber 0 1 2 3 4 5 Tubers 2 10 5 5 2 1 1 4 5 6 3 6 3 2 7 8 1 4 10 9 3 1 1 1 17 6 1 1 3 7 7 2 3 3 9 10 5 4 9 4 3 2 3 12 8 3 2 5 5 11 4 15 9 1 10 9 4 2 10 5 5 3 2 25 25 25 25 25 25 25 25 25 25 25 25 25 1 8 4 12 40 68 12 36 16 48 20 60 40 40 1.9 3.0 2.6 1.1 0.4 2.2 1.0 2.0 0.8 1.6 0.4 0.9 1.3 1Tuber samples collected at harvest and held at room temperature for later abrasive peeling and scoring. 2Tuber samples collected at harvest, held at 50ºF for at least 12 hours, then placed in a 6 sided plywood drum and rotated 10 times to produce simulated bruising. They were then held at room temperature for later abrasive peeling and scoring. 69 Table 7A. Pre-Harvest Panels, 8/24/10 % Canopy Number of Specific Glucose1 Sucrose2 Gravity 1.072 1.073 1.073 1.069 1.065 1.072 1.074 1.079 1.063 1.070 1.066 1.062 1.083 Average5 Tuber Rating Rating3 Uniform.4 Hills Stems Weight 6.84 0.568 4.00 0.385 4.68 0.297 4.80 0.363 0.228 5.89 5.65 0.280 5.73 0.363 5.02 0.419 0.469 5.48 4.36 0.226 4.24 0.720 3.64 0.280 0.636 4.71 0.013 0.002 0.002 0.002 0.002 0.002 0.002 0.005 0.002 0.002 0.002 0.001 0.002 90 90 95 95 95 95 90 90 90 80 90 90 90 90 80 85 75 75 90 85 80 20 10 60 85 70 9 17 28 10 7 11 13 17 7 18 13 12 12 5 5 4 4 4 4 4 5 3 5 7 5 5 Entry AF2291-10 W5015-12 Snowden MSL292-A NY138 Atlantic NY139 W2310-3 W2978-3 CO97065-7W MSJ126-9Y CO97043-14W W2717-5 1Percent Glucose is the percent of glucose by weight in a given amount of fresh tuber tissue. 2Sucrose Rating is the percent of sucrose by weight in a given amount of fresh tuber tissue X10. 3 The Canopy Rating is a percent rating of green foliage (0 is all brown dead foliage, 100 is green vigorous foliage). 4 The Canopy Uniformity is a percentage of how uniform the foliage health is at the date of observation. 5 The Average Tuber Weight is the total tuber weight collected divided by the number of tubers reported in ounces. Table 7B. Pre-Harvest Panels, 9/7/10 % Canopy Number of Specific Glucose1 Sucrose2 Gravity 1.079 1.080 1.076 1.075 1.071 1.076 1.076 1.085 1.064 1.070 1.064 1.069 1.065 Average5 Tuber Rating Rating3 Uniform.4 Hills Stems Weight 6.51 0.503 4.24 0.312 3.99 0.484 0.452 5.92 5.07 0.299 4.34 0.417 4.74 0.428 0.275 4.48 5.23 0.434 5.21 0.286 3.37 0.705 0.316 4.94 3.92 0.796 0.003 0.002 0.002 0.002 0.002 0.002 0.002 0.003 0.003 0.002 0.002 0.001 0.003 90 90 95 95 95 95 95 90 85 95 90 85 90 45 35 40 35 35 50 40 35 15 5 20 30 30 9 15 24 9 7 18 15 15 12 15 10 13 19 5 4 3 4 4 4 5 5 4 6 4 5 5 Entry AF2291-10 W5015-12 Snowden MSL292-A NY138 Atlantic NY139 W2310-3 W2978-3 CO97065-7W MSJ126-9Y CO97043-14W W2717-5 1Percent Glucose is the percent of glucose by weight in a given amount of fresh tuber tissue. 2Sucrose Rating is the percent of sucrose by weight in a given amount of fresh tuber tissue X10. 3 The Canopy Rating is a percent rating of green foliage (0 is all brown, dead foliage, 100 is green, vigorous foliage). 4 The Canopy Uniformity is a percentage of how uniform the foliage health is at the date of observation. 5 The Average Tuber Weight is the total tuber weight collected, divided by the number of tubers reported in ounces. 70 2010 MSU Tablestock Potato Variety Trials Entry Pedigree 2010 Scab Rating* Classic Russet (A95109-1Rus) Blazer Russet X Summit Russet 1.3** Bannock Russet X A94020-3 *Scab rating based on 0-5 scale; 0 = most resistant and 5 = most susceptible. ** 2009 data Characteristics Medium yield, early maturity, attractive appearance, high percentage of US#1’s, fresh market use, low - medium specific gravity, resistant to fusarium dry rot and common scab, some tuber storage rot and blackleg susceptibility reported High yield, oval to oblong tubers, smooth red skin, shallow eyes, medium maturity Long to oval tubers, heavy russet, check variety High yield, early maturity, round tuber type, low specific gravity, smooth skin, white flesh, medium deep eyes, few internal defects, check variety High yield, bright tubers, low incidence of internal defects, mid to late season maturity, medium – low specific gravity Medium yield, mid-season maturity, long to oval tubers, heavy russet skin, check variety, low specific gravity High yield, oblong to long blocky tuber type, medium russet skin, masks PVY, medium specific gravity, possible Sencor & Linuron susceptibility Medium yield, early to mid-season maturity, medium specific gravity, heavy russeting Yields similar to Russet Norkotah but higher US No.1 count, heavily russeted, bright eyes Medium yield, early to mid-season maturity, medium specific gravity, heavy russeting, nice uniform blocky tuber appearance 3.5 1.0 2.1 2.5 2.3 1.0 - 0.5 1.5 Colorado Rose NDTX9-1068-11R X NT6063-1R GoldRush (ND1538-1Rus) ND450-3Rus X Lemhi Russet Onaway USDA X96-56 X Katahdin Reba (NY 87) Monona X Allegany Russet Norkotah (ND534-4Rus) ND9526-4Rus X ND9687-5Rus Silverton Russet (AC83064-6) A76147-2 X A 7875-5 A98134-2Rus A98289-1Rus A01124-3Rus A86707 X A9201-6 A9396-1 X Premier Russet 71 Entry A0008-1TERus CO99256-2R Pedigree Blazer Russet X Classic Russet Rio Colorado X Colorado Rose CO99053-3Rus AC91014-2 X Silverton Russet CO00291-5R MSL211-3 MSL268-D CO94019-1R X Rio Colorado MSG301-9 x Jacqueline Lee (MSG274-3) NY103 X Jacqueline Lee MSM182-1 Stirling X NY121 MSQ176-5 MSQ440-2 MSR217-1R MSS544-1R W2609-1R MSI152-A X Missaukee (MSJ461-1) MSK214-1R X Missaukee (MSJ461-1) NDTX4271-5R X Missaukee (MSJ461-1) CO93037-6R X MNR-8RR Dark Red Norland X W774R 2010 Scab Rating* - 2.8 2.0 2.5 2.2 3.0 3.0 3.0 1.8 Characteristics Medium yield, nice blocky tuber type, white flesh, medium russet skin, early maturity, low specific gravity Medium to late maturity, oval tuber type, strong red skin color High yield, medium to late maturity, large vine, medium specific gravity, uniform blocky tubers, medium russeting, nice appearance, blackspot resistant Medium yield, uniform round tubers, late maturity, dark red skin color Round to oval tubers, smooth bright appearance, moderate late blight resistance, good yield Medium – high yield, late blight resistance, round to oval tuber type PVY & late blight resistance, low specific gravity, smaller size profile High yield potential, uniform round tuber type, bright appearance, late blight resistance, good bulking Uniform round tubers, very bright white skin, common scab resistant 2.0 Attractive dark red skin, round tuber type 1.0 1.0 Attractive dark red skin, round tuber type, common scab resistance Some common scab tolerance, moderate red skin color, uniform round type *Scab rating based on 0-5 scale; 0 = most resistant and 5 = most susceptible. 72 Entry W2683-2Rus W5767-1R W6234-4Rus W8946-1Rus Pedigree ND4093-4 X CO80011-5 MN96101-1 X MN86105 Umatilla Russet X A9014-2 PA98V1-2 X AOA95154-1 2010 Scab Rating* 1.0 2.0 3.5 1.3 Characteristics Good yield, high percent of oversize, good internal quality, blackspot resistant, common scab resistance, medium low specific gravity, tuber shape may not be consistent Dark red skin, white flesh, large tuber size, high yield potential, medium deep eyes, large vine, medium late maturity Large vine type, blocky tubers, very light russet skin, high specific gravity Medium yield potential, medium specific gravity, possibly susceptible to heat stress *Scab rating based on 0-5 scale; 0 = most resistant and 5 = most susceptible. 73 2010 Freshpack Potato Variety Trial Overall Averages - Seven Locations Branch, Delta, Kalkaska, Monroe, Montcalm, Newaygo & Presque Isle NUMBER OF LOCATIONS LINE US#1 TOTAL US#1 CWT/A PERCENT OF TOTAL1 Bs OV As PO SP GR HH TUBER QUALITY2 VD IBS BC TOTAL CUT VINE VIGOR3 MATURITY4 VINE COMMENTS 1 3 3 4 7 4 4 3 4 4 5 4 2 3 Classic Russet 592 636 W5767-1R 453 498 Colorado Rose 450 525 MSQ176-5 442 486 Silverton Russet 441 519 CO99265-2R 440 505 Reba 440 476 Onaway 417 487 MSL268-D 393 465 MSL211-3 369 432 CO99053-3RUS 368 500 MSM182-1 352 421 A98134-2RUS 350 543 CO00291-5R 348 394 93 91 85 89 85 87 92 78 84 84 74 83 66 88 1 6 9 8 10 11 6 17 10 12 13 14 26 6 24 77 65 56 58 82 78 61 77 77 51 79 61 83 69 14 20 33 27 5 14 17 7 7 6 3 6 3 5 2 2 5 6 4 1.077 1.071 1.068 1.063 1.069 1.073 1.072 1.066 1.080 1.069 23 13 1.075 4 5 5 3 8 6 1.070 1.075 1.066 1 0 0 2 3 1 0 0 3 0 8 3 0 6 0 5 4 4 8 9 2 8 13 4 6 2 5 3 0 0 0 2 1 0 0 0 0 0 1 4 1 0 0 0 0 0 7 0 0 0 0 0 0 2 0 0 10 30 30 40 70 40 40 30 40 40 50 40 20 30 3.5 4.5 4.0 2.9 2.7 3.3 3.8 4.7 3.8 4.3 2.6 3.9 3.0 2.7 4.5 large percent of oversize 2.2 2.2 3.0 3.1 3.2 2.3 1.5 3.1 2.1 surface scab, sl netted skin, tr gc, misshapen pickouts misshapen pickouts, surface and pitted scab, oblong tuber type, tr soft rot surface and pitted scab, gc in pickouts, nice tuber type, sl netted skin, bright appearance misshapen pickouts, sl alligator hide surface and pitted scab, oval to oblong tuber type, good red color tr surface and pitted scab, deep apical eye, gc in pickouts, oblong tuber type bright appearance, sl deep eye, gc and misshapen in pickouts, tr surface and pitted scab tr surface and pitted scab, knobs in pickouts, buff / netted appearance smooth bright appearance, gc and misshapen tubers in pickouts, tr surface scab 4-YR AVG US#1 CWT/A 423 435* * 450* 435* * 397 443* * 427 374 385 369* 4.1 not uniform type, alligator hide, large tuber size 433* * * 2.5 tr pitted scab, netted skin, severe heat necrosis 402* * * 2.3 4.5 misshapen in pickouts, tr gc, alligator hide, type not uniform surface and pitted scab, misshapen pickouts, sticky stolons 350* 348* 74 NUMBER OF LOCATIONS LINE US#1 TOTAL US#1 CWT/A PERCENT OF TOTAL1 Bs OV As PO SP GR HH TUBER QUALITY2 VD IBS BC TOTAL CUT VINE VIGOR3 MATURITY4 VINE COMMENTS misshapen pickouts, heavy russeting 358* * * tr surface scab, misshapen pickouts, one tuber with severe VD 3.1 gc and misshapen tubers in pickouts 2.0 many gc and misshapen in pickouts, alligator hide 323* * tr = trace, sl = slight, N/A = not applicable SED = stem end defect, gc = growth crack *One-Year Average * *Two-Year Average * * *Three-Year Average 3 1 5 2 3 4 5 6 3 1 4 1 W2609-1R 345 384 A98289-1RUS 332 431 W6234-4RUS 323 447 A01124-3RUS 322 502 MSR217-1R 286 315 MSQ440-2 279 333 W8946-1RUS 276 496 Russet Norkotah 266 396 GoldRush 260 434 MSS544-1R 229 308 W2683-2RUS 217 386 A0008-1TE MEAN 209 354 348 449 89 77 70 64 90 82 56 65 62 74 54 60 10 17 23 30 9 17 28 27 20 20 26 18 86 73 54 56 81 76 54 54 57 65 45 48 3 4 16 8 9 6 2 11 5 9 9 12 1 6 7 6 1 1 16 8 18 6 20 22 1.061 1.070 1.078 1.072 1.059 1.058 1.087 1.066 1.068 1.064 1.073 1.063 1.070 0 0 2 3 0 0 2 0 0 0 3 6 4 3 8 0 3 20 4 13 2 2 4 0 0 0 0 2 1 1 6 1 0 0 4 0 1 0 0 1 0 0 0 0 0 0 0 0 30 10 50 20 30 40 50 60 30 10 40 10 3.8 1.0 3.1 1.3 2.2 3.0 3.1 2.8 1.3 2.5 2.4 1.0 1SIZE Bs: < 1 7/8" or < 4 oz. 2TUBER QUALITY (number of tubers per total cut) HH: Hollow Heart 3VINE VIGOR RATING Date Taken: N/A As: 1 7/8" - 3.25" or 4 - 10 oz. VD: Vascular Discoloration Ratings: 1 - 5 OV: > 3.25" or > 10 oz. IBS: Internal Brown Spot 1: Slow Emergence PO: Pickouts BC: Brown Center 5: Early Emergence (vigorous vine, some flowering) 4MATURITY RATING Date Taken: N/A Ratings: 1 - 5 1: Early (vines completely dead) 5: Late (vigorous vine, some flowering) 1.0 1.5 2.1 surface and pitted scab, gc in pickouts, light red skin color gc and misshapen in pickouts, severe blackleg rot in plot tr surface scab, light russeting, misshapen pickouts, heat sprouts, heat necrosis in two tubers 2.5 misshapen pickouts, heavy russeting 1.3 2.4 surface and pitted scab, dark red skin color, uniform round type, tr gc in pickouts 1 glassy end, sl surface scab, some heat sprouts, bright appearance 3.6 sl surface scab, severe heat sprouts in pickouts alligator hide, uniform type, misshapen and knobs in pickouts 1.6 1.7 2.0 4-YR AVG US#1 CWT/A 345* 393* * 323* 322* 286* 279* 276* 325 229* 328* * 75   2010 Weed Control Projects in Potato  Dr. Wesley Everman, Andrew J. Chomas and Chris Long    Delayed Release Nitrogen Effect on Potato Yield and Vine Kill,  Nitrogen fertilizer is one of the most costly inputs in potato production and the most important  input for maximizing potato tuber yield.  Field research was conducted in 2010 to examine:  1)   The effect of controlled release and conventional urea‐ammonium nitrate on potato yield.  2)   Controlled release based fertility programs on vine vigor and vine kill.  The site was established  on a loamy sand soil with 2.2% OM a pH of 5.1 and at the Montcalm Research Farm, Entrican  Michigan.  The experiment was conducted in a factorial design with four replications.  Individual  plots were 3.5 meter wide and 7.6 meter long, consisting of four potato rows spaced at 0.86  meter.  ‘Snowden’ variety tubers were planted on May 17, 2010. Treatments consisted of either  controlled release (CR) or conventional 28% urea‐ammonium nitrate (UAN) solution applied at  a rate of 67 kg/ ha at planting, first cultivation and hilling followed by 112 kg/ha (urea) surface  applied in late July for a total of 12 treatments.  Vine kill treatments consisted of diquat + NIS  (.28 kg ai/ha + .25% v/v/ha) followed by diquat + NIS (.28 kg ai/ha  + .25% v/v/ha), glufosinate  (.43 kg ai/ha), and a control treatment (no vine kill).  Irrigation and other potato crop  management practices followed that of commercial seed producers.  Vine kill was evaluated  visually 14, 21 and 28 days after treatment.   Also, normalized difference vegetation index  (NDVI) measurements were collected.  Potato tubers were harvested and yields determined.   There were no significant differences observed between herbicides in regards to potato vine  kill.  There was a very strong significant correlation between visual rating and NDVI  measurements.  No differences in potato vine vigor, using NDVI, among fertilizer program or  herbicide were observed.  In marketable tuber yield there were no significant differences.         76 Efficacy and Selectivity of Solida when Applied PRE and POST to Potato  A study investigating the tolerance of potato to applications of rimsulfuron formulations was  conducted in 2010 at the Montcalm Research Farm.  The study compared .75, 1.5 and 3 oz use  rates of two formulations of rimsulfuron applied at CRACKING and EARLY POST.  The results  indicate there were no differences in weed control observed between the two formulations for  any application timing.    Late Season Weed Control in FL‐1922  Potato varieties are known to have varying growth habits which can affect late season  management. Weed control in potato is most effective when implemented as a preventative  system as few herbicides are available for postemergence weed control. The greatest weed  problems often become apparent late in the season in varieties with low vine vigor, and after  postemergence herbicides have been applied. Grass weeds such as large crabgrass, giant  foxtail, and barnyardgrass and broadleaf weeds including nightshade, common purslane, and  common lambsquarters often germinate in July and compete with potato for nutrient resources  during the critical bulking period in August and early September. Tubers were planted May 17th  at the Montcalm Research Farm at a 10‐inch spacing in rows 34‐inches apart.  Each treatment  was replicated four times. Treatments consisted of early postemergence and postemergence  applications. Preemergence herbicides were applied to all plots and consist of Dual Magnum at  1.33 pt/A plus Lorox at 1.5 qt/A; early postemergence options andincluded Prowl at 1.8 pt/A,  Boundary at 1.5 pt/A, V10142 at 8.5 oz/A, and No Early Postemergence; postemergence  options will consist of Matrix at 1 oz/A, Sencor at 0.33 lb/A, V10142 at 8.5 oz/A, Matrix plus  Sencor, and No Postemergence for a total of 21 treatments.  The results indicate there were no  differences in weed control observed among the various weed control strategies.        77 Halosulfuron Weed Control in Potato  A study investigating  weed control in potato with applications of halosulfuron, metribuzin and  metolachlor combinations in 2010 at the Montcalm Research Farm.  The study compared PRE  and POST strategies using various combinations of these herbicides.  Research indicates that  halosulfuron has the potential as a herbicide for use in potato.    Rimsulfuron Tank Mixes  A study investigating weed control in potato using various tank‐mixes of rimsulfuron,  dimethenamid, sulfentrazone, metribuzin and metolachlor applied PRE, POST and PRE followed by  POST was conducted in 2010 at the Montcalm Research Farm. This study compared various weed  control strategies using tank‐mixes and timing strategies to attain season long weed control.     Effects of ALS Herbicides on Potatoes  A study investigating weed control in potato using various tank‐mixes of CGA‐362622,  thifensulfuron, sulfentrazone, metribuzin and metolachlor applied PRE, POST and PRE followed by  POST was conducted in 2010 at the Montcalm Research Farm. This study compared various weed  control strategies using tank‐mixes and timing strategies to attain season long weed control.     Maverick PRE in Potato  Five treatments were implemented comparing sulfosulfuron tank mixed with metolachor and  metolachor and metribuzin at Montcalm Research farm in 2010.  The treatments investigated were  all applied PRE.  The primary objective of this study was to evaluate sulfosulfuron as a potential  herbicide for use in potato.    78 Vine Desiccation with Vida  A study was conducted in 2010 to evaluate the efficacy of Vida applied as a vine kill product. The  study was conducted at the Montcalm Research Farm using Silverton as the potato variety.  The  variety Silverton was chosen as to challenge the vine kill treatments.  This particular variety is  known for its vigor and heavy growth.  All herbicide treatments were compared with a non‐treated  control treatment. Each treatment was replicated four times. Irrigation and other potato crop  management practices utilized closely mirror practices followed by producers. At 28 days after  application acceptable levels of vine kill were not obtained with any treatment.   The highest level  of control was 69%.    However some visual differences among treatments provide valuable  information among products.    Effects of Compost and Weed Competition on Potato Growth and Yield  Increased agricultural sustainability in disturbed systems through bio‐amendment addition can lead to  increases in soil organic matter, increases in productivity, and improvements in soil health.  However,  organic amendments also increase the growth and competitive ability of weeds when compared to  synthetic fertilizer, which may affect weed control and crop yield.  A field study was established in 2010  in Entrican, MI to investigate the effect of compost rate on weed competition in potato.  Three compost  rates (0 ton acre‐1, 10 ton acre‐1, and 20 ton acre‐1) were incorporated in late April.  Rates were based on  application of carbon (0 ton acre‐1, 1.8 ton C acre‐1, and 3.6 ton C acre‐1) because the compost was used  as a soil amendment rather than a nutrient source.  ‘Snowden’ variety potatoes (Solanum tuberosum)  were planted mid‐May at 10.5 inch seed spacing with 34 inch row spacing.  Hairy nightshade (Solanum  physalifolium), giant foxtail (Setaria faberi), or common lambsquarters (Chenopodium album) seedlings,  1, 3, or 1 inch, respectively, were transplanted into the row at 1.6 plants foot‐1 at potato cracking.  Plant  height and biomass were collected and recorded throughout the season.  Data was subjected to analysis  of variance with significance determined with α<0.05.  No significant differences in biomass or height  were observed within a species due to compost rate differences.  Tuber yield and quality were evaluated  at harvest, and significant differences were observed in yield from both weed species and compost rate.   There was a significant loss in marketable tuber weight and number due to the presence of giant foxtail  (271 cwt acre‐1; 5.28 x 105 tubers acre‐1) or hairy nightshade (270 cwt acre‐1; 5.16 x 105 tubers acre‐1)  when compared to the weed free (357 cwt acre‐1; 6.35 x 105 tubers acre‐1), and potatoes grown in  79 competition with common lambsquarters yielded less than all other treatments (176 cwt acre‐1; 3.48 x  105 tubers acre‐1).   Total potato yield was also impacted significantly.  The weed free treatment had a  total potato weight of 394 cwt acre‐1, giant foxtail and hairy nightshade competition resulted in  significant yield reductions compared to the weed free of 20.2 and 20.5%, respectively, and common  lambsquarters competition significantly reduced yield by 47.7%.  The treatments under giant foxtail  competition produced similar total number of tubers to the weed free, 7.51 x 105 acre‐1 and 8.17 x 105  acre‐1, respectively,  but hairy nightshade treatments produced significantly fewer tubers (7.23 x 105  acre‐1) than the weed free, and common lambsquarters treatments produced fewer tubers than all  other treatments (4.99 x 105 acre‐1).  Compost rate also impacted the number of marketable tubers,  where the high compost rate treatments produced significantly more tubers (5.53 x 105 acre‐1) than the  low (4.77 x 105 acre‐1) and non‐amended treatments (4.91 x 105 acre‐1).  Total yield was greatest under  the high compost rate treatments (336 cwt acre‐1), and was significantly greater than the low (293 cwt  acre‐1) and non‐amended (292 cwt acre‐1) treatments.  Weed competition decreased marketable and  total tuber yield and number, but the degree of reduction was species dependent.  There was also an  increase in marketable tuber number and total yield at the highest compost rate.  Compost addition  may increase marketable tuber production without increasing the competitive ability of the weeds, but  this study still demonstrates the importance of weed control in the cropping system.  This study will be  repeated in 2011.      80 Soil treatments for control of Verticillium wilt and Common Scab of potatoes, 2010. W. W. Kirk1, R. L Schafer1, C. Huthinson2 and C. Furman2 1Department of Plant Pathology, Michigan State University, East Lansing, MI 48824; 2Hendrix and Dale. Soil treatments were applied at the Michigan State University Potato Research Farm, Clarksville, MI (Sandy loam soil complex Alfic Haplorthod; 1.8% OM; pH 6.2); 43.3526, -85.1761 deg; elevation 951 ft on 23 Apr by a tractor-mounted soil injection system calibrated to deliver 70. 98, 116 and 140 lb/A of the products PicPlus 85.5AP and Vapam 32.7EC 73.5 gal/A into prepared seedbeds 12 ft wide x 70 ft long. The seedbeds were replicated four times in a randomized complete block design. Potato seed (“FL1879”) was prepared for planting by cutting two days prior to planting. Seed were planted on 18 May ca. 9-in between plants at 34-in row spacing to give a target population of 20,000 plants/A. Fertilizer was drilled into plots before planting, formulated according to results of soil tests. Additional nitrogen (final N 28 lb/A) was applied to the growing crop with irrigation 45 DAP (days after planting). Bravo WS 6SC 1.5 pt/A was applied on a seven-day interval, total of eight applications, for foliar disease control. Weeds were controlled by hilling and with Dual 8E at 2 pt/A 10 DAP, Basagran at 2 pt/A 20 and 40 DAP and Poast at 1.5 pt/A 58 DAP. Insects were controlled with Admire 2F at 1.25 pt/A at planting, Sevin 80S at 1.25 lb/A 31 and 55 DAP, Thiodan 3 EC at 2.33 pt/A 65 and 87 DAP and Pounce 3.2EC at 8 oz/A 48 DAP. Vines were killed with Reglone 2EC (1 pt/A on 15 Sep). Plots (4 x 70- ft row) were harvested on 4 Oct and individual treatments were weighed and graded. Four plants per plot were harvested on 24 Aug [98 days after planting (DAP); 123 days after soil application (DASA)] and the percentage of stems and tubers with signs or symptoms of Verticillium stem wilt and tuber discoloration (vascular beading) were calculated. Tubers were washed and assessed for common scab (S. scabies) incidence (%) and severity. Samples of 100 tubers per plot and stored at 50oF and evaluated 14 days after harvest (153 DAP; 178 DASA). Severity of common scab was measured as an index calculated by counting the number of tubers (n = 100) falling in class 0 = 0%; 1 = 1 - 5%; 2 = 6 -10%; 3 = 11 - 15; 4 >16% surface area of tuber covered with tuber lesions (surface and pitted). The number in each class was multiplied by the class number and summed. The sum was multiplied by a constant to express as a percentage. Indices of 0 - 25 represent 0 - 5%; 26 - 50 represent 6 - 10%; 51 - 75 represent 11 - 15% and 75 - 100 >15% surface area covered with lesions. Meteorological variables were measured with a Campbell weather station located at the farm from 1 Apr to harvest (4 Oct). Maximum, minimum and average daily air temperature (oF) were 81.7 25.9 and 50.6 (Apr); 90.2, 27.5 and 59.4 (May); 86.4, 43.6 and 66.7 (Jun); 90.4, 43.9 and 72.7 (Jul); 91.0, 44.9 and 71.6 (Aug); 84.3, 38.8 and 59.2 (Sep); 68.1, 29.4 and 46.8 (to 4 Oct). Maximum, minimum and average daily soil temperature at 2” depth (oF) were 68.2, 37.2 and 52.1 (Apr); 83.0, 42.8 and 61.5 (May); 82.3, 58.5 and 71.4 (Jun); 86.2, 61.4 and 74.7 (Jul); 88.9, 59.4 and 73.8 (Aug); 76.8, 51.9 and 63.1 (Sep); 67.5, 44.5 and 54.9 (to 4 Oct). Maximum, minimum and average daily soil temperature at 4” depth (oF) were 58.7, 34.2 and 46.4 (Apr); 72.3, 39.2 and 54.9 (May); 72.7, 54.0 and 64.3 (Jun); 75.7, 56.5 and 67.0 (Jul); 77.4, 53.9 and 65.4 (Aug); 68.8, 46.5 and 55.5 (Sep); 57.3, 39.9 and 48.1 (to 4 Oct). Maximum, minimum and average soil moisture at 4” (% of field capacity) was 19.4, 14.8 and 15.9 (Apr); 22.3, 11.7 and 15.6 (May); 21.2, 16.2 and 17.7 (Jun); 25.0, 16.9 and 18.5 (Jul); 26.9, 16.8 and 18.8 (Aug); 23.8, 16.3 and 17.7 (Sep) and 16.3, 15.9 and 16.1 (to 4 Oct). Precipitation was 1.59 in. (Apr), 3.68 in. (May), 3.21 in. (Jun), 2.14 in. (Jul), 2.63 in (Aug), 1.88 in. (Sep) and 0.23 in. (to 4 Oct). Plots were irrigated to supplement precipitation to about 0.1 in./A/4 day period with overhead sprinkle irrigation. No treatment affected final plant stand or the rate of emergence (data not shown). No treatments affected Verticillium wilt in either the stems or the tubers measured as stem wilt or tuber discoloration both of which developed over the season to a significant degree throughout the trial. Common scab developed 81 in the trial and untreated plots had about 76% incidence and 45% severity scale score by 14 days after harvest, which on a quality scale would have made them difficult to market. PicPlus at the three higher rates significantly reduced common scab incidence and severity in comparison to the untreated control and to Vapam. All soil applied products increased US1 and total yield in comparison to the untreated control. Soil treatments were not phytotoxic. Table 1. Efficacy of PicPlus against Verticillium wilt and commons scab of potato, 2010. Stems with Verticillium (%)z 89.5 100.0 97.9 84.4 93.4 100.0 22.44 Tuber number per plant 10.4 11.0 12.0 8.5 11.9 11.6 4.95 Tubers with Verticillium (%)z 63.2 60.9 48.2 60.0 51.1 73.3 18.40 Treatment and rate/A Vapam 32.7EC 37.5 gal (Aw) PicPlus 85.5AP 70 lb PicPlus 85.5AP 98 lb PicPlus 85.5AP 116 lb PicPlus 85.5AP 140 lb Untreated Check……………….......... HSD0.05 Common Scab Incidence (%)y av 73.8 60.0 a 40.0 b 40.0 b 36.3 b 76.3 a 16.71 Severity Scale (%)x a 45.0 30.6 ab 19.7 b 19.4 b 19.1 b 45.0 a 16.52 US1 a 214.9 a 188.6 a 254.0 a 202.1 251.9 a 104.6 b 74.13 Yield (cwt/A) B-size a a a a a a Treatment and rate/A Vapam 32.7EC 37.5 gal PicPlus 85.5AP 70 lb PicPlus 85.5AP 98 lb PicPlus 85.5AP 116 lb PicPlus 85.5AP 140 lb Untreated Check……………….......... HSD0.05 z Four plants per plot were harvested on 24 Aug [98 days after planting (DAP); 123 days after soil application (DASA)] and the percentage of stems and tubers with signs or symptoms of Verticillium stem wilt and tuber discoloration (vascular beading) were calculated. y Scab-free tubers; percentage falling in severity class 0 = 0%. x Severity of common scab was measured as an index calculated by counting the number of tubers (n = 200) falling in class 0 = 0%; 1 = 1 - 5%; 2 = 6 -10%; 3 = 11 - 15; 4 >16% surface area of tuber covered with tuber lesions (surface and pitted). w A = Soil treatments applied on 23 Apr by a tractor-mounted soil injection system v Values followed by the same letter are not significantly different at p = 0.05 (Honest Significant Difference; Tukey Multiple Comparison). 297.7 318.0 295.4 311.4 325.7 264.4 44.03 Total a 512.6 a 506.6 a 549.4 a 513.5 577.7 a 369.0 b 83.4 82 Seed treatments and seed plus in furrow treatments for control of seed- and soil-borne Rhizoctonia solani, 2010. W. W. Kirk, J. Hao, R. L Schafer and P. Tumbalam Department of Plant Pathology, Michigan State University, East Lansing, MI 48824 Funding MPIC and Industry Potatoes with Rhizoctonia solani (black scurf), 2- 5% tuber surface area infected, were selected for the trials. Potato seed (Dark Red Norland) was prepared for planting by cutting and treating with fungicidal seed treatments two days prior to planting. Seed were planted at the Michigan State University Horticultural Experimental Station, Clarksville, MI (Capac loam soil); 42.8733, -85.2604 deg; elevation 895 ft. on 21 May into two-row by 20-ft plots (ca. 10-in between plants to give a target population of 50 plants at 34-in row spacing) replicated four times in a randomized complete block design. The two-row beds were separated by a 5-ft unplanted row. Dust formulations were measured and added to cut seed pieces in a Gustafson revolving drum seed treater and mixed for 2 min to ensure even spread of the fungicide. Fungicides applied as pre-planting potato seed liquid treatments were applied in water suspension at a rate of 0.2 pt/cwt onto the exposed seed tuber surfaces, with the entire seed surface being coated in the Gustafson seed treater. In- furrow at-planting applications were delivered at 8 pt water/A in a 7 in. band using a single XR11003VS nozzle at 30 p.s.i. Foliar applications were applied with a R&D spray boom delivering 25 gal/A (80 p.s.i.) and using three XR11003VS nozzles per row. Fertilizer was drilled into plots before planting, formulated according to results of soil tests. Additional nitrogen (final N 28 lb/A) was applied to the growing crop with irrigation 45 DAP (days after planting). Previcur Flex was applied at 0.7 pt/A on a seven-day interval, total of four applications, starting one day after inoculation of adjacent plots with Phytophthora infestans to prevent spread of potato late blight. Weeds were controlled by hilling and with Dual 8E at 2 pt/A 10 DAP and Poast at 1.5 pt/A 58 DAP. Insects were controlled with Admire 2F at 1.25 pt/A at planting, Sevin 80S at 1.25 lb/A 31 and 55 DAP, Thiodan 3 EC at 2.33 pt/A 65 and 87 DAP and Pounce 3.2EC at 8 oz/A 48 DAP. Vines were killed with Reglone 2EC (1 pt/A on 15 Sep). Plots (20-ft row) were harvested on 6 Oct and individual treatments were weighed and graded. Four plants per plot were harvested 51 days after the final treatment application (7 Jul) and the percentage of stems and stolons with greater than 5% of the total surface area affected were counted. An index of below ground health was evaluated 47 DAP on a scale of 0 - 5 where 0 = no symptoms of stem canker, 1 = 1 – 5%, 2 = 6 – 10%, 3 = 11 – 20%, 4 = 21 – 50%, 5 = 50 – 100% of the surface of roots, stolons and stem affected by R. solani. Samples of 50 tubers per plot were harvested 14 days after desiccation and assessed for black scurf (R. solani) incidence (%) and severity 40 days after harvest. Severity of black scurf was measured as an index calculated by counting the number of tubers (n = 50) falling into each class 0 = 0%; 1 = 1 - 5%; 2 = 6 -10%; 3 = 11 - 15; 4 >15% surface area of tuber covered with sclerotia. The number in each class is multiplied by the class number and summed. The sum is multiplied by a constant to express as a percentage. Indices of 0 - 25 represent 0 - 5%; 26 - 50 represent 6 - 10%; 51 - 75 represent 11 - 15% and 75 - 100 >15% surface area covered with sclerotia. Meteorological variables were measured with a Campbell weather station located at the farm from 1 May to harvest (15 Jul). Maximum, minimum and average daily air temperature (oF) were 89.4, 28.8 and 59.7 (May); 86.3, 45.4 and 66.9 (Jun); 90.2, 46.4 and 73.1 and 1-d with maximum temperature >90oF (Jul); 90.6, 46.8 and 71.9 and 2-d with maximum temperature >90oF (Aug); 85.7, 40.2 and 60.1 (Sep); 85.7, 31.0 and 53.4 (to 15 Oct). Maximum, minimum and average relative humidity (%) was 92.8, 42.5 and 65.3 (May); 90.5, 55.4 and 73.4 (Jun); 90.8, 60.9 and 80.6 (Jul); 98.4, 33.6 and 72.3 (Aug); 98.7, 30.8 and 73.3 (Sep); 98.7, 19.3 and 68,5 (to 15 Oct). Maximum, minimum and average daily soil temperature (oF) were 77.8, 53.1 and 66.5 (May); 89.2, 54.6 and 74.0 (Jun); 94.5, 59.8 and 76.7 (Jul); 89.2, 65.2 and 78.5 (Aug); 86.9, 65.7 and 76.8 (Sep); 78.2, 56.6 and 64.9 (to 15 Oct). Maximum, minimum and average soil moisture (% of field capacity) was 38.4, 28.8 and 31.7 (May); 39.9, 32.3 and 34.7 (Jun); 38.6, 34.1 and 35.4 (Jul); 39.5, 32.9 and 35.2 (Aug); 42.0, 31.3 and 34.5 (Sep) and 42.0, 33.4 and 34.2 (to 15 Oct). Precipitation was 3.82 in. 83 Funding MPIC and Industry (May), 4.48 in. (Jun), 4.33 in. (Jul), 1.4 in (Aug), 5.14 in. (Sep) and 0.7 in. (to 15 Oct). Plots were irrigated to supplement precipitation to about 0.1 in./A/4 day period with overhead sprinkle irrigation. The trials were divided into two sets; the first group of treatments was shown in Set 1 (Table 1). No treatment affected final plant stand. Moncoat MZ increased the rate of emergence (RAUEPC) in comparison to the untreated control. Moncoat MZ and Serenade ASO at the lowest application rate increased marketable yield in comparison to the untreated control but no other treatments were significantly different from the untreated control. No treatments had an affect on total yield. Treatments with greater than 4.7 stems had significantly more stems per plant than the untreated control. All treatments except the mid rate of Serenade ASO applied in-furrow had significantly less stem canker than the untreated check. The total number of stolons per plant was not affected by any treatment. All treatments had significantly less stolon canker incidence in comparison to the untreated check. All treatments had significantly less overall lower stem plant canker in comparison to the untreated check. All treatments had significantly lower incidence and severity of tuber black scurf in comparison to the untreated check. Seed treatments and in-furrow applications of fungicides and biofungicides were not phytotoxic (Table 1). Set 2; (Table 2). No treatment affected final plant stand or the rate of emergence (RAUEPC). Marketable yield and total ranged from 123 to 200 cwt/A (untreated check = 149.7 cwt/A) and 320 to 557 cwt/A (untreated check = 432.1 cwt/A), respectively, but no treatments were significantly different from the untreated check or from the standard commercial seed treatment Maxim FS. Maxim 4FS had significantly more stems than the untreated check and Maxim 4FS 0.16 fl oz/cwt (A) +Actinogrow 0.0371WP 0.9 oz significantly less but no other treatments affected stem number. All treatments except the lowest rate of maxim plus Actinogrow had significantly less stem canker than the untreated check. The total number of stolons per plant was not affected by any treatment. All treatments had significantly less stolon canker incidence in comparison to the untreated check. All treatments had significantly less overall lower stem plant canker in comparison to the untreated check. All treatments had significantly lower incidence and severity of tuber black scurf in comparison to the untreated check. Seed treatments and seed treatment plus fungicide applications of fungicides were not phytotoxic. (Table 2). 84 a (%) RAUEPCz Final plant stand Table 1. Efficacy of fungicides and biofungicides on Rhizoctonia stem canker and black scurf (Set 1). Treatment and rate/1000 row feet and rate/cwt potato seed Moncoat MZ 7.5DP 0.75 lb/cwt (Ay)….. Serenade ASO 1.34SC 2.2 fl oz (B)…… Serenade ASO 1.34SC 7.7 fl oz (B)…… Serenade ASO 1.34SC 13.2 fl oz (B)….. Quadris 2.08FL 0.6 fl oz (B)…………... Nubark Gold 6DS 1 lb/cwt (A)………... Nubark Mancozeb 6DS 1 lb/cwt (A)….. Nubark Mancozeb AS 8DS 1 lb/cwt (A). Maxim 4FS 0.08 fl oz/cwt + Nubark Gold 6DS 1 lb/cwt (A)………... Maxim 4FS 0.08 fl oz/cwt + WE Germinate 10DS 0.2 oz/cwt (A)…. Untreated Check……………….............. HSD0.05 US1 176.9 b 206.8 a 160.6 bc 157.7 bc c 152.8 c 154.2 148.3 c c 147.7 48.5 39.4 bcd 38.5 bcd 35.7 cd 33.9 d 34.1 d 38.2 bcd 41.4 bc 162.1 bc 144.4 c 19.92 99.0 96.5 96.0 90.0 85.5 96.0 93.5 95.5 92.5 95.0 10.31 42.6 ab 40.4 bcd ax a a a a a a a 159.4 bc 6.85 43.1 96.0 a a ab a Stems (35 DAP) Stolons (35 DAP) Root and lower stem Incidence Girdlingv canker index 35 DAPu bc 2.2 2.3 b 1.9 bcd cde 1.6 ef 1.2 1.1 ef f 0.9 1.0 ef > 5% b No./ plant 17.6 17.6 15.1 14.8 17.8 15.0 17.3 16.8 Number 5.6 a 4.1 c 4.2 bc ab 4.6 a 5.5 5.3 a ab 4.7 5.3 a Percent infectedw c 26.8 47.6 b ab 53.4 c 21.7 c 18.3 23.0 c c 21.7 21.1 c Treatment and rate/1000 row feet and rate/cwt potato seedz Moncoat MZ 7.5DP 0.75 lb/cwt (Ay)….. Serenade ASO 1.34SC 2.2 fl oz (B)…… Serenade ASO 1.34SC 7.7 fl oz (B)…… Serenade ASO 1.34SC 13.2 fl oz (B)….. Quadris 2.08FL 0.6 fl oz (B)…………... Nubark Gold 6DS 1 lb/cwt (A)………... Nubark Mancozeb 6DS 1 lb/cwt (A)….. Nubark Mancozeb AS 8DS 1 lb/cwt (A). Maxim 4FS 0.08 fl oz/cwt + Nubark Gold 6DS 1 lb/cwt (A)………... Maxim 4FS 0.08 fl oz/cwt + 0.9 WE Germinate 10DS 0.2 oz/cwt (A)…. 4.0 Untreated Check……………….............. 0.67 HSD0.05 z RAUEPC = Relative area under the emergence progress curve measured from planting to 31 days after planting y Application dates: A= 19 May (liquid formulations for seed piece application at 0.2 pt/cwt; B= 21 May (in-furrow). x Values followed by the same letter are not significantly different at p = 0.05 (Honest Significant Difference; Tukey Multiple Comparison). w Stems with greater than 5% of area with stem canker due to Rhizoctonia solani v Stolons with greater than 5% of area with stolon canker due to Rhizoctonia solani. u An index of below ground health was evaluated 35 DAP on a scale of 0 - 5 (see text) (%) 3.8 d 13.8 bcd 10.0 cd 13.8 bcd 18.8 bc 23.8 ab cd 11.3 10.0 cd 9.8 8.9 bc 7.6 bc 4.5 bcd 4.9 bcd 3.6 cd 2.0 d 4.9 bcd 4.8 bcd 26.5 5.43 10.0 32.5 11.37 19.6 63.6 14.16 5.2 3.9 0.94 14.8 14.1 3.97 1.4 def 7.7 bc cd a 20.7 18.0 21.3 ef a c c a abc 5.1 ab a c a Funding MPIC and Industry Yield (cwt/A) Total 401.2 a  425.8 a  370.0 a  329.5 a  365.4 a  369.5 a  319.0 a  364.7 a  401.7 a  343.9 a  332.9 a  78.69 Tuber black scurf Severity scale d (0 - 100) 1.3 4.7 bcd 2.8 cd 5.9 bcd 9.1 bc 10.3 b 3.4 cd 5.6 bcd 9.1 bc cd a 3.1 17.2 6.68 85 Funding MPIC and Industry Yield (cwt/A) a a a a a ax (%) 93.5 48.3 95.0 97.0 45.5 US1 162.9 122.9 RAUEPCz Final plant stand Table 2. Efficacy of fungicides and biofungicides on Rhizoctonia stem canker and black scurf (Set 2). Treatment and rate/1000 row feet and rate/cwt potato seed Maxim 4FS 0.16 fl oz/cwt (Ay) + Actinogrow 0.0371WP 0.3 oz (Ay)... Maxim 4FS 0.16 fl oz/cwt (A) + Actinogrow 0.0371WP 0.6 oz (B)…. Maxim 4FS 0.16 fl oz/cwt (A) + Actinogrow 0.0371WP 0.9 oz (B)… Maxim 4FS 0.16 fl oz/cwt (A) + Tenet 4WP 0.5 oz (B)……………… Maxim 4FS 0.16 fl oz/cwt (A) + Quadris 2.08SC 0.6 fl oz (B)………. LEM 17 200EC 0.67 fl oz (B)…......... LEM 17 200EC 1.6 fl oz (B)…........... YT669 200EC 0.7 fl oz (B)…………. YT669 200EC 0.7 fl oz (B)…………. Q8Y78 240SC 1.6 fl oz (B)…………. LEM 17 4.75FS 0.42 fl oz (B)………. LEM 17 4.75FS 0.21 fl oz (B)………. LEM 17 4.75FS 0.11 fl oz (B)………. Quadris 2.08SC 0.6 fl oz (B)………... Maxim MZ 6.2DS 0.5 lb/cwt (A)…… Maxim 4FS 0.16 fl oz/cwt (A)……… Untreated Check……………….......... HSD0.05 199.9 171.2 187.4 158.8 167.7 158.3 189.8 152.7 175.3 180.4 192.3 180.5 149.7 43.35 51.4 43.8 45.5 47.9 49.0 50.5 48.5 48.7 47.8 47.0 44.4 49.2 44.3 9.26 99.5 99.0 99.5 98.5 98.5 99.5 93.5 97.0 98.5 97.5 95.5 99.0 97.0 a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a 6.65 183.1 167.2 94.5 48.2 41.1 a a a a a a Stems (35 DAP) Stolons (35 DAP) Total 320.3 362.7 434.6 345.3 491.8 395.3 468.5 399.1 338.3 393.7 557.1 380.8 443.9 424.1 407.6 412.6 432.1 148.29 a a a a a a a a a a a a a a a a a Tuber black scurf Root and lower stem canker index 35 DAPu ab cd ab cd cd Girdlingv 4.3 4.9 6.1 0.4 14.6 13.4 19.4 15.0 13.6 > 5% 1.7 b 7.7 b 3.9 d 2.2 d No./ plant Number 1.3 bc 2.5 de 20.0 b 7.5 b-e 0.8 bcd 5.0 bcd 6.0 bcd 4.4 bcd 10.0 b-e 10.1 bcd 13.4 bcd Incidence (%) Percent infectedw Treatment and rate/1000 row feet and rate/cwt potato seedz Maxim 4FS 0.16 fl oz/cwt (Ay) + Actinogrow 0.0371WP 0.3 oz (Ay)... Maxim 4FS 0.16 fl oz/cwt (A) + Actinogrow 0.0371WP 0.6 oz (B)…. Maxim 4FS 0.16 fl oz/cwt (A) + Actinogrow 0.0371WP 0.9 oz (B)… Maxim 4FS 0.16 fl oz/cwt (A) + Tenet 4WP 0.5 oz (B)……………… Maxim 4FS 0.16 fl oz/cwt (A) + 1.2 bcd Quadris 2.08SC 0.6 fl oz (B)………. 1.1 bcd LEM 17 200EC 0.67 fl oz (B)…......... 1.6 b LEM 17 200EC 1.6 fl oz (B)…........... 0.8 bcd YT669 200EC 0.7 fl oz (B)…………. 1.3 bc YT669 200EC 0.7 fl oz (B)…………. 0.7 bcd Q8Y78 240SC 1.6 fl oz (B)…………. 1.4 bc LEM 17 4.75FS 0.42 fl oz (B)………. 0.8 bcd LEM 17 4.75FS 0.21 fl oz (B)………. 1.1 bcd LEM 17 4.75FS 0.11 fl oz (B)………. 0.3 d Quadris 2.08SC 0.6 fl oz (B)………... 1.1 bcd Maxim MZ 6.2DS 0.5 lb/cwt (A)…… 1.5 b Maxim 4FS 0.16 fl oz/cwt (A)……… 3.2 a Untreated Check……………….......... 1.03 HSD0.05 z RAUEPC = Relative area under the emergence progress curve measured from planting to 31 days after planting y Application dates: A= 19 May (liquid formulations for seed piece application at 0.2 pt/cwt; B= 21 May (in-furrow). x Values followed by the same letter are not significantly different at p = 0.05 (Honest Significant Difference; Tukey Multiple Comparison). w Stems with greater than 5% of area with stem canker due to Rhizoctonia solani v Stolons with greater than 5% of area with stolon canker due to Rhizoctonia solani. u An index of below ground health was evaluated 35 DAP on a scale of 0 - 5 (see text) 7.5 b-e cde 6.3 0.0 e 11.3 b-e 16.3 bc 0.0 e 7.5 b-e 5.0 cde 11.3 b-e 5.0 cde 13.8 bcd 10.0 b-e 33.8 13.22 15.9 14.7 13.6 16.0 16.0 14.4 17.8 15.9 18.3 17.0 15.2 15.4 16.3 18.9 3.53 14.4 bcd 10.5 bcd 15.9 bc 9.1 bcd 13.3 bcd 6.6 cd 17.1 bc 8.6 bcd 13.7 bcd 2.5 d 10.3 bcd 16.2 bc 31.3 a 12.75 5.6 bc 5.6 bc 5.2 bcd 5.3 bc 5.9 b 4.5 cd 5.5 bc 5.4 bc 5.3 bcd 5.9 b ab 6.1 7.4 a 5.5 bc 1.36 4.6 bcd 5.1 bcd 7.7 b 5.6 bcd 7.1 b 4.9 bcd 5.6 bcd 5.4 bcd 4.1 bcd 3.1 cd 5.2 bcd 6.5 bc a 3.83 a Severity scale (0 - 100) 2.5 bcd 7.5 b 2.5 bcd 0.6 d 3.1 bcd 2.5 bcd 0.0 d 3.8 bcd 6.3 bc 0.0 d 2.5 bcd 1.3 cd 4.1 bcd 1.3 cd 4.1 bcd 3.1 bcd 13.1 5.35 a 86 Funding: MPIC and MSU GREEEN Impact of different US genotypes of Phytophthora infestans on potato seed tuber rot and plant emergence in different cultivars and breeding lines Kirk, W. 1, Rojas, A.1, Abu-El Samen, F.1, Tumbalam, P.1, Wharton, P.1, Douches, D.2, Thill, C.A.3, Thompson, A.4 1 Department of Plant Pathology, Michigan State University, East Lansing, MI, USA. 2 Department of Crop and Soil Sciences, Michigan State University, East Lansing, MI, USA. 3 Department of Horticulture Science, University of Minnesota, St. Paul, MN, USA. 4 Plant Sciences Department, North Dakota State University, Fargo, ND, USA. Introduction Globally, Phytophthora infestans (Mont.) de Bary remains a threat to the potato crop, causing significant losses annually (Guenther et al. 2001). Under favorable conditions, foliar and tuber late blight are the most common symptoms resulting in tuber rotting in the field and storage, and affecting the economic value of the potatoes. Infected volunteer tubers can lead to a late blight epidemic in the following season. The transmission of potato late blight from tuber to sprouts has been confirmed (Berkeley 1846; Appel et al. 1998), but the progression mechanism from infected tubers to the plant is not fully understood. Potato cultivars with higher foliar resistance tend to slow down the epidemics leading to longer periods of vegetative growth of P. infestans. As a result, zoospores and mycelia can be washed into the soil (Bain et al., 1997). This fact may provide a high risk of tuber infection. In addition, the populations of P. infestans have changed to more aggressive genotypes, like US–8, which is highly aggressive on foliage, and also in tubers and sprouts (Kirk et al., 2009). The changing P. infestans population has not been fully understood at in terms of virulence, fitness, aggressiveness and transmission. Also, the dynamics of potato blight development in tubers is highly influenced by temperature (Kirk et al., 2009) resulting in non–emergence of plants due to seed and sprout rot. The objectives of this study were to evaluate the potential of different genotypes of P. infestans to impact plant establishment in potato cultivars and advanced breeding lines (ABLs) with different resistance to potato late blight. Methods Tubers for this study were obtained from the potato breeding programmes at Michigan State University, the University of Wisconsin, the University of Minnesota and North Dakota State University. Potato tubers from cultivars/ABLs harvested during the previous growing seasons were stored at 3 °C in the dark at 90% relative humidity until they were used. Tubers for the experiments were within the size grade range 50–150 mm diameter (any plane). Visual examination of a random sample of tubers from each entry for disease symptoms indicated that tubers were free from late blight. The sample was further tested with the ELISA immunodiagnostic Alert multiwell kit (Alert multiwell kit– Phytophthora sp., Neogen, Lansing, MI, USA). P. infestans was not detected in any of the tubers. Prior to inoculation, all tubers were washed with water to remove soil. The tubers were then surface-sterilized by soaking them in 2% sodium hypochlorite (Clorox) solution for 30 min. Tubers were dried in a controlled environment with continuous airflow at 15 °C in dry air (30% relative humidity) for 4 h prior to inoculation. Cultures of P. infestans–isolates Pi95-3 (US-1), Pi96-2 [US-1.7 (restriction fragment length polymorphism genotype; Young et al. 2009)], Pi02-007 (US-8), Pi96-1 (US- 11) and 87 Funding g: MPIC and d MSU GRE EEEN US-14) wer an State Univ nized mixtur (9 cm diame uspension of ogenized mix re selected versity) and re of myceli eter × 15 mm f 105 and 10 xture of myc as the mos grown on ry ium and spo m depth Petr 06 spores/ml, celium and s st aggressiv ye agar Petri orangia of P ri plates) fro , exposing th sporangia of ve isolates f i plates for14 P. infestans w om each isol he cut surfa P. infestans from the co 4 days in the was prepared late. Tubers ace was plac s for 30 s. ollection of e dark at 18 ° d from 200 s were inocu ced face dow Kirk °C. A plate ulated wn on Pi98-1 ( (Michiga homogen cultures ( with a su the homo P otato cultiva culation and after inoc net bags with dark in n anged in a c were arra (Chagrin n Falls, Ohio ment rates w developm ents (Kirk et experime (DAI). ft ter incubatio ed surface of inoculate ars/ABLs us d re-storage. hin ventilated complete ran o 44022-039 within tubers al. 2001c) a on (30 DAI) f inoculated sed for the e Tubers were d plastic box ndomized de 90) in darkn s in relation and a single , seed piece seed pieces experiments e inoculated xes. Each tre esign and st ness at 10 ° to storage sampling da es were cut 2 to assess tub were evalua as described eatment was tored in envi °C and 90% temperature ate was selec 25, 50 and 7 ber blight de ated for tube d and were t s replicated f ironmental g % relative h e were know cted 30 days 75% from an evelopment i er blight sev then stored i four times. B growth cham umidity. Di wn from prev s after inocul nd parallel t in the tuber t verity in the Boxes mbers isease vious lation to the tissue. F or plant sta and, eight se cultivars/ /ABLs, were e planted 5 d by two gu separated uard plants as a rando arranged mized comp of emerged p number o plants was re (%) and the relative e area unde ). n et al. 2007 (Wharton D Data for all e e JMP prog using the Carolina 27513, USA experiments gram versio A). eed pieces p DAI at the (cv. Red N plete block ecorded ove er the emer per replicate Muck Soils Norland) at t design. In er a 60-day p rgence progr e per treatm Research F the ends of the plant e period after p ress curve ment from 1 Farm (Laings f each plot. establishmen planting and (RAUEPC) 2 and 16 p sburg, MI, U Both trials nt experimen d final plant were calcu potato USA) were nt the stand ulated were analy on 7.0 (SAS yzed by anal S Institute I lysis of vari Inc., SAS C iance (least Campus Dri squares me ive, Cary, N ethod) North T Table 1. Varie an nd tuber ratin eties/ABLs ch ng against US- hallenged dur -8 (symbols r ring the study referred to in y including th Fig 2). he breeders’ e stimate for fo oliar 88 Funding g: MPIC and d MSU GRE EEEN F Figure 1. Cros ge enotype. Num ss sections of mbers indicat f a tuber from te RARI (%) f the line ND2 for apical, mi 2443 inoculate iddle, basal se ed with P. inf ections. festans US–8 sion and Discuss Results a • RAR exper • Rega which • The U • All th tissue • Figur • The f infest contr • The g • In 20 2004 • Mean lower • Final Howe inocu • Folia seed RI (%) values riment (Fig 2 ardless of the h means a lo US–14 genot he cultivars a e (RARI %) re 2 shows th final plant st tans genotyp rol seed piec genotypes U 003, cv. Atlan , cv. Torrido n RAUEPC o r in 2003 and l plant stand ever, RAUE ulated. ar symptoms pieces. s, for 2003 st 2). e variety or A ower RARI ( type was the and ABLs de after the ino he response tand of tuber pe US-8 and es. US-1 and US- ntic had the on had the hi of seed piece d 2004. and RAUEP EPC and fina torage (10ºC C) were signi ificantly gre eater compar red to the 200 04 ABL inocula (%) value (F e second mo emonstrated oculation wit of the variet rs (ratio of pl US-14 were ated, US–8 g Fig 1). st aggressive d significant th different g ties/ABLs is lants growin e significantl -11 also redu greatest fina ighest final p es infected w uced the fina al plant stand plant stand. with genotyp genotype cau used the mo ost damage, e genotype i differences genotypes of correlated t ng to seeds p ly lower than in tubers in b in the amoun f P. infestan to the tuber d planted) inoc an the non– i both the year rs. ic nt of necroti s. disease. culated with noculated P. al plant stand d among P. i d. infestans gen notypes; for r pes US-8 and d US-14 wer re significan ntly PC were pos al plant stand sitive correla d values were ated for both e different fo h years’ trials for varieties/ s (Fig 3). ABLs of late bligh ht were abse nt on plants emerging fr rom the diffe erent inocula ated 89 Funding g: MPIC and d MSU GRE EEEN equency and d rate of tran smission fro om infected t tubers to fol iage he emerged plants from m the inocula ated seed pie • In fac is stil • The a could ct, the questi ll unresolved absence of la d be affected ion of the fre d. ate blight sym d by different mptoms in th t factors. F Figure 2. RAU va arieties/ABLs UEPC express s with differe sed as functio nt genotypes on of tuber su of P. infestan usceptibility (m ns in 2003 an mean RARI % nd 2004. %) across ce 90 Funding g: MPIC and d MSU GRE EEEN F Figure 3. RAU di ifferent genot UEPC express types of P. inf sed as a funct festans in 200 tional of final 03 and 2004. l plant stand ( (%) across va arieties/ABLs with Conclusi A correla pathogen infestans infection ion ation was ob nicity lowers s isolates is in n of tuber and bserved betw s the field est ncreasing, m d sprouts cou ween tuber su tablishment more breedin uld be leadin usceptibility (Kirk et al., ng lines on tu ng cause for and plant gr 2009). As t uber resistan a new epide rowth, where the aggressiv nce could be emic. e tuber veness of P. helpful. La atent Referenc Appel R, infesta Phyto ces , et al. (2001 ans and po pathology 1 d for the artif 1) A method olymerase c hain reactio 2. 49: 287-292 ficial inocula on assay of ation of pota f latently i ato tubers w infected spr with Phytoph routs and s thora tems. Bain RA infecti Europ PAV- Berkeley Phyto 108 pp Guenther growe Kirk, W. 2009. and pl 121–1 A, et al. (199 ion of tuber pean Networ Special Rep 97) The role rs. In: Boum rk for Develo ort No. 1, Ja e of Phytoph ma E, Schep opment of a anuary 1997 hthora infes pers H, eds an Integrated . 98–105. stans inoculu s. Proceedin d Control Str um from ste ngs of the W trategy of Po em lesions i Workshop on otato Late B in the n the Blight. y MJ (1846 pathological p East Lansi tions, botan 6) Observat No. 8. Amer l Classics N ing, MI, USA A. r JF, Michae ers. Potato R el, KC and N Res 44: 121-1 Nolte, P (200 125 nical and p rican Phytop physiologica pathological al, on the Society. 19 potato mu 948 reproduc urrain. ction. 01) The econ nomic impac ct of potato late blight o on US .W., F. Abu Impact of d lant emergen 140. u-el, P.W. Sa different US nce in a rang amen, D. D S genotypes ge of cultiva ouches, P. T of Phytoph ars and advan Tumbalam, thora infesta nced breedin C. Thill, an tans on pota ng lines. Pot nd A. Thomp ato seed tube tato Researc mpson. er rot ch 51: 91 Funding: MPIC and MSU GREEEN Niemira BA, Kirk WW and Stein JM (1999) Screening for late blight susceptibility in potato tubers by digital analysis of cut tuber surfaces. Plant Diseases 83: 469-473. Wharton PS, Kirk WW, Berry DR, Tumbalam PG (2007) Seed treatment application-timing options for control of Fusarium decay and sprout rot of cut seedpieces. Am J Potato Res 84:237–244 Young GK, Cooke LR, Kirk WW, Tumbalam P, Perez FM, Deahl KL (2009) The influence of competition and host plant resistance on selection of Phytophthora infestans populations in Michigan State and Northern Ireland. Plant Pathol doi:10.1007/BF02986273 92 COLORADO POTATO BEETLE RESEARCH UPDATE Zsofia Szendrei (szendrei@msu.edu) and Adam Byrne Department of Entomology, Michigan State University, East Lansing, MI 48824 Lab website: http://vegetable.ent.msu.edu/ The Colorado potato beetle is the most widespread and destructive insect pest of potato crops in the eastern United States and Canada. Its ability to develop resistance to insecticides makes it very important to continue testing the efficacy of both new insecticide chemistries and existing compounds. Such tests provide data on comparative effectiveness of products and data to help support future registrations and use recommendations. Objective 1. Field evaluations of registered insecticides for managing Colorado potato beetle on potatoes METHODS. Twenty-seven insecticide treatments and an untreated check (Table 1) were tested at the MSU Montcalm Research Farm, Entrican, MI for control of Colorado potato beetle. ‘Atlantic’ potato seed pieces were planted 12 in. apart, with 34 in. row spacing on 13 May 2010. Treatments were replicated four times in a randomized complete block design. Plots were 40 ft. long and three rows wide with untreated guard rows bordering each plot. Admire Pro, Platinum 75SG, and Regent 4SC treatments were applied as in-furrow sprays at planting, using a single-nozzle hand-held boom (30 gallons/acre and 30 psi). Seed treatments (HGW86 60 FS treatments, Titan 60 SL, Admire Pro, and Cruiser Max) were applied by mixing seed pieces for each row with the corresponding amount of product in a small plastic bag and shaking until seed pieces were thoroughly coated. Foliar treatments were first applied at greater than 50% Colorado potato beetle egg hatch on 17 June. Based on the economic threshold of more than one large larva per plant, only the Agri-Flex 1.55 SC treatment required an additional first generation spray, applied on 1 July. Post-spray counts of Colorado potato beetle adults, small larvae (1st and 2nd instars), and large larvae (3rd and 4th instars) of four randomly selected plants form the middle row of each plot were made 5 or 6 days after each foliar application. The numbers of small larvae, large larvae and adults were transformed (log + 0.1) prior to analysis. Multivariate analysis of variance was used for data analysis, with block and date as random factors and insecticide treatment as fixed factor. Ad-hoc Tukey means comparison was used to compare treatment means when the overall model was significant (P < 0.01). Plots were visually rated for defoliation weekly by estimating total defoliation per plot. Percent defoliation values were arcsine transformed prior to analysis, and an analysis of variance was done with block and date as random factors and insecticide treatment as fixed factor in the model. Ad-hoc Tukey means comparison was used to compare treatment means when the overall model was significant (P < 0.05). On 14 September, the middle row of each plot was harvested mechanically and the tubers were weighed. Data were analyzed using analysis of variance with treatment as fixed and block as random factor in the model and significant treatment differences were determined with Tukey post-hoc means separation test (P < 0.05). RESULTS. All treatments significantly reduced the numbers of small larvae, large larvae, and adults on plants compared to the untreated plots (Table 1). Beetle pressure was higher in 2010 than in 2009, but comparing to previous years, insect pressure was low overall. Nevertheless, the untreated plots had significantly greater defoliation compared to all other treatments (F = 11.46; df = 27, 446; P < 0.01). The seasonal defoliation average was 13% in untreated plots, compared to less than 2% for all other treatments (there were no statistically significant differences between insecticide treatments). Growing conditions were favorable this season, with dry, hot weather leading to rapid plant growth, likely outpacing the impacts of Colorado potato beetle feeding damage. Overall average yield was 33,211.7 lb/A, with no significant differences between any of the treatments (F = 0.72; df = 27, 110; P = 0.8285). While neonicotinoid insecticides are still providing sufficient Colorado potato beetle control for Michigan farmers, it is reassuring to see other chemical classes also providing adequate control (i.e.: Coragen, Regent, Agri-Mek, and Rimon). Regent is currently registered for use in potato for wire-worm control. Rimon is only effective when applied to larvae that still need to grow and molt since this product contains a hormone that inhibits development to the next growing stage. With the slow increase in neonicotinoid resistance seen in Michigan (see the section below for more details on this), it remains important to have effective non-neonicotinoid compounds available for second generation control and/or for future use if neonicotinoid resistance becomes a significant problem.  93 Objective 2. Insecticide resistance monitoring of Colorado potato beetles in Michigan potato fields Imidacloprid (Admire Pro) and thiamethoxam (Platinum, Actara) continue to be the most common means of Colorado potato beetle control. Today, greater than 75% of the acres in the northeastern and midwestern United States are protected by these compounds (NASS 2006). Such consistent and heavy dependency on any compound sets the stage for resistance development. Further complicating the issue is the availability of generic imidacloprid formulations; these formulations drive down product cost, which will likely lead to even greater field exposure to these compounds. All of these reasons strongly support the need to continue monitoring resistance development and to encourage growers to adopt strong resistance management strategies. Our objective was to continue gathering data on susceptibility to imidacloprid and thiamethoxam in Colorado potato beetle populations collected from commercial potato fields in Michigan and other regions of the United States. To accomplish this objective, 15 Colorado potato beetle populations (10 Michigan populations and 5 populations collected in other states) were bioassayed with imidacloprid and/or thiamethoxam. METHODS. During 2010, 10 Colorado potato beetle populations were collected from 4 Michigan counties (Mecosta, Montcalm, St. Joseph, and Tuscola). Cooperators also provided a population from New York and two each from Maine and Virginia. One laboratory strain was also tested (Table 2). Adult Colorado potato beetles were treated with 1 µl of acetone/insecticide solution of known concentration applied to the ventral surface of the abdomen using a 50 µl Hamilton® microsyringe. A range of five to nine concentrations was selected for each population, depending on the number of available beetles and known resistance history for each population. In each bioassay, 20-30 adults were treated with each concentration (nine to 10 beetles per dish and two to three dishes per concentration). Following treatment, beetles were placed in 100 mm diam. petri dishes lined with Whatman® No. 1 filter paper and provided with fresh potato foliage. They were kept at 25±1°C and the foliage and filter paper were checked daily and changed as needed. Beetle response was assessed 7 days post treatment. A beetle was classified as dead if its abdomen was shrunken, it did not move when its legs or tarsi were pinched, and its elytra were darkened. A beetle was classified as walking and healthy if it was able to grasp a pencil and walk forward normally. A beetle was classified as poisoned if its legs were extended and shaking, it was unable to right itself or grasp a pencil, and it was unable to walk forward normally at least one body length. Beetles that had died due to Beauvaria spp. infection were excluded from analysis; these beetles were easily recognized by their pale, petrified appearance and/or presence of white filamentous fungi. Dead and poisoned beetle numbers were pooled for analysis. Data were analyzed using standard log-probit analysis (SAS Institute, 2009). RESULTS. The imidacloprid LD50 value (dose lethal to 50% of the beetles) for the susceptible laboratory strain was 0.208 µg/beetle (Table 3), statistically higher than in previous years. The LD50 values from the field for imidacloprid ranged from 1.573 µg/beetle (Sackett Ranch field VG) to 12.738 µg/beetle (Tuscola) for Michigan populations (Figure 1). However, the St. Joseph sample had 100% mortality at the lowest dose tested (0.3 µg/beetle); since all doses tested caused 100% mortality, the analysis was unable to calculate an LD50 value, but clearly this is the most susceptible population tested. On the other hand, the Tuscola population showed almost no response to all doses tested, resulting in a projected LD50 value of 12.738 µg/beetle, but lacked confidence limits, a very high value for the Midwest. The imidacloprid LD50 values from the out-of-state populations ranged from 0.104 µg/beetle (Painter, VA) to 20.428 (Jamesport, NY). significantly higher values than the susceptible laboratory strain. One possible cause for the elevated values was a change in methodology from previous years. In 2010, we did not put beetles in cold-storage prior to testing, whereas in previous years, populations were subjected to a week or more of cold-storage (11±1°C). Instead, beetles were maintained at room temperature and fed daily until bioassays were conducted. Regardless, as in 2009, all Michigan imidacloprid LD50 values were significantly higher than the susceptible comparison. In 2010, 60% of the Michigan samples were greater than 10-fold resistant to imidacloprid, compared to 85% in 2009 and 90% in 2008. LD50 values were generally higher this year, with all but one population (Fryeburg, ME) having The thiamethoxam LD50 value for the susceptible laboratory strain was 0.112 µg/beetle, also statistically higher than in previous years. LD50 values for thiamethoxam in Michigan ranged from 0.152 µg/beetle (St. Joseph) to 3.248 µg/beetle (Montcalm), and from 0.134 µg/beetle (Bridgewater, ME) to 1.152 µg/beetle (Jamesport, NY) for out-of-state populations (Figure 1). Unlike the past two years, where no Michigan populations showed greater than 10-fold resistance to thiamethoxam, two populations tested (Montcalm and  94 Thiamethoxam resistance remains uncommon and has probably been delayed by the more prevalent use of imidacloprid in the field. However, now that some Michigan sites are showing greater than 10-fold resistance to thiamethoxam, it will be important to monitor thiamethoxam resistance even closer, even more important to avoid multiple applications of neonicotinoids in a single growing season, and essential to alternate with other chemical classes for Colorado potato beetle control. Objective 3. Understand the molecular genetic processes of resistance in CPB. In April 2010, a postdoctoral researcher joined our laboratory specifically to work on understanding the Tuscola) were more than 10-fold resistant to thiamethoxam. The 3.248 µg/beetle value from Montcalm is particularly high, representing the highest field thiamethoxam value we’ve recorded. molecular genetic causes of insecticide resistance in CPB. So far, we have extracted RNA from CPB kept in our laboratory colonies. Currently, there are two populations that we will focus on in our genetic analyses, one imidacloprid resistant and another highly susceptible to insecticides. From the resistant population, we extracted RNA from CPB guts before and after selection with imidacloprid, in order to compare gene expression profiles before and after induction. RNA is sequenced at the MSU Genomic Core Facility on an Illumina sequencer. Each treatment is replicated three times, and this will provide us with information on the individual variation in the genetic basis of insecticide resistance. Our goal is to identify genes that are involved with insecticide resistance. Once we get the sequence data from the genomic core facility, we will use bioinformatics to evaluate gene expression. In addition, the postdoctoral researcher is currently conducting bioassays to test the role of different enzymes in helping the insect metabolize insecticides. These experiments involve the inhibition of well-known insecticide metabolism enzymes in insects and measuring the response of the treated insects to insecticides. Through the response of enzyme-inhibited insects to insecticide treatment, we will be able to identify which enzymes take active part in insecticide metabolism. For this objective, additional funding was attained in 2010 for three years from the Rackham Foundation.  95 Table 1. Seasonal mean number of different Colorado potato beetle life stages in an insecticide field-trial conducted by the MSU vegetable entomology laboratory. Application mode seed treatment seed treatment seed treatment seed treatment seed treatment seed treatment seed treatment seed treatment seed treatment foliar foliar foliar foliar foliar Rate 9.4 g ai/100 kg 4.7 g ai/100 kg 9.0 g ai/100 kg 6.8 g ai/100 kg +6.3 g ai/100 kg 9.0 g ai/100 kg +6.3 g ai/100 kg 6.8 g ai/100 kg +3.1 g ai/100 kg 6.8 g ai/100 kg +9.4 g ai/100 kg 9.0 g ai/100 kg +9.4 g ai/100 kg 6.3 g ai/100 kg 3.4 fl oz/A 6.8 fl oz/A 10.1 fl oz/A 13.5 fl oz/A 7 fl oz/A Adult1 0.7 a 0.0 b 0.0 b 0.0 b 0.1 b Small Larva1 1.4 a 0.0 b 0.0 b 0.2 b 0.0 b Large Larva1 4.8 a 0.1 b 0.0 b 0.1 b 0.0 b 0.0 b 0.0 b 0.0 b 0.1 b 0.3 b 0.0 b 0.0 b 0.0 b 0.0 b 0.0 b 0.0 b 0.0 b 0.0 b 0.0 b 0.1 b 0.0 b 0.1 b 0.2 b 0.3 b 0.1 b 0.3 b 0.0 b 0.0 b 0.2 b 0.1 b 0.0 b 0.0 b 0.0 b 0.0 b 0.1 b foliar foliar foliar foliar foliar foliar 4 oz/A 0.1 b 0.1 b 0.0 b 0.79 fl oz/A 0.01 b 0.3 b 0.1 b 7 fl oz/A 0.1 b 0.4 b 0.7 b 4 fl oz/A 0.0 b 0.1 b 0.1 b 2.8 fl oz/A 0.1 b 0.4 b 0.4 b 3.8 fl oz/A 0.0 b 0.1 b 0.4 b Treatment Untreated Admire Pro Cruiser Max HGW86 60 FS HGW86 60 FS + Titan 60 SL HGW86 60 FS + Titan 60 SL HGW86 60 FS + Titan 60 SL HGW86 60 FS + Admire Pro HGW86 60 FS + Admire Pro Titan 60 SL HGW86 10 OD HGW86 10 OD HGW86 10 OD HGW86 10 OD Coragen 1.67 SC Voliam Flexi 40 WG Agri-Flex 1.55 SC Voliam Xpress 1.25 ZC Endigo 2.06 ZC Leverage 360 Leverage 2.7 Insecticide class neonicotinoid neonicotinoid cyantraniliprole cyantraniliprole + lambdacyahalothrin cyantraniliprole + lambdacyahalothrin cyantraniliprole + lambdacyahalothrin cyantraniliprole + neonicotinoid cyantraniliprole + neonicotinoid lambdacyhalothrin cyantraniliprole cyantraniliprole cyantraniliprole cyantraniliprole ryanodine receptor modulator neonicotinoid + ryanodine receptor modulator neonicotinoid + chloride channel activator pyrethroid + ryanodine receptor modulator pyrethroid + neonicotinoid pyrethroid + neonicotinoid pyrethroid + neonicotinoid chloride channel activator growth inhibitor neonicotinoid neonicotinoid + spinetoram neonicotinoid neonicotinoid chloride channel modulator Agri-Mek 0.15 EC Rimon 0.83EC Scorpion 35 SL Scorpion 35 SL Radiant SC Admire Pro Platinum 75 SG Regent 4 SC 1 Different letters within a column denote statistically significant differences among treatments. 16 fl oz/A 12 fl oz/A 3.0 fl oz/A 3.0 fl oz/A 8.0 fl oz/A 8.7 fl oz/A 2.67 oz/A 3.2 fl oz/A foliar foliar foliar foliar (alternated weekly) infurrow infurrow infurrow 0.1 b 0.1 b 0.0 b  0.0 b 0.1 b 0.1 b 0.0 b 0.0 b 0.1 b 0.2 b 0.1 b 0.1 b 0.2 b 0.1 b 0.0 b 0.0 b 0.0 b 0.5 b 0.0 b 0.0 b 0.1 b 96 Table 2. Colorado potato beetle populations tested for susceptibility to imidacloprid and thiamethoxam in 2010. Michigan populations Montcalm Farm Summer adults were collected on 14 July 2010 from untreated potatoes at the Michigan State University Montcalm Potato Research Farm, Entrican, MI. Paul Main Farm Summer adults were collected by Mark Otto, Argi-Business Consultants, Inc. from commercial potato fields in Mecosta County. Field H6 (old field number HB-Hen) Adults were collected just north of Lakeview on 12 July 2010; adults were migrating from volunteer potatoes in field H5 (old field number HB-NS) corn. Field H6 is NW of Paul Main’s field H4 (old field number HB-S [Shurlow]) that had a very high summer adult LD50 value a few years ago. Field R13 Adults were collected in Rodney on 12 July 2010; adults were migrating from volunteer potatoes in field R1 corn. Sackett Potatoes Summer adults were collected by Mark Otto, Argi-Business Consultants, Inc. from commercial potato fields in Mecosta and Montcalm Counties. Field 14 Adults were collected from Home farm trap rows, Mecosta County on 12 July 2010. Field 132 Adults were collected from northeast of Remus, Mecosta County (same population as fields 101-107) on 12 July 2010; adults were migrating from potato volunteers in fields 135-136 corn. Fields 152-153 Adults were collected in Montcalm County on 17 July 2010. Overwintered adults migrated from field 150-151; food control early from Admire Pro, but should have sprayed 1st generation larvae earlier. Sackett Ranch Field VG1-2-7 Summer adults were collected on 12 July 2010 from a commercial potato field in southeast Edmore, Montcalm County; adults migrated in from potato volunteers from field VG3-4 corn. There has been no beetle pressure in this area for years and years. St. Joseph Summer adults were collected by Karl Ritchie, Walther Farms on 13 July 2010 from a commercial potato field in St. Joseph County. Sturgis Summer adults were collected in August from a commercial potato field near Sturgis, St. Joseph County. Tuscola Summer adults were collected on 20 July 2010 from a commercial potato field in Tuscola County. Out-of-state populations Bridgewater, Maine Overwintered adults were collected in June 2010 by Andrei Alyokhin, University of Maine, from a commercial potato field near Bridgewater, ME. Fryeburg, Maine Overwintered adults were collected on 2 June 2010 by Andrei Alyokhin, University of Maine, from a commercial potato field near Fryeburg, ME. Jamesport, New York Overwintered adults were collected on 2 June 2010 by Sandra Menasha, Cornell Cooperative Extension, from a commercial potato field in Suffolk County, NY. New Church, Virginia Overwintered adults were collected on 13 May 2010 by Tom Kuhar, Virginia Polytechnic Institute and State Universiy, from a commercial potato field near New Church, VA. Painter, Virginia Summer adults were collected on 14 June 2010 by Tom Kuhar, Virginia Polytechnic Institute and State Universiy, from a commercial potato field in Painter, VA Laboratory strain New Jersey Adults obtained in 2008 from the Phillip Alampi Beneficial Insects Rearing Laboratory, New Jersey Department of Agriculture and since reared at Michigan State University without contact to insecticides.  97 Table 3. LD50 values (µg/beetle) and 95% fiducial limits for Colorado potato beetle populations treated with imidacloprid and thiamethoxam at 7 days post treatment. LD50 (µg/beetle) 95% Confidence Intervals [lowest dose (0.3) had 100% mortality] 1.530 – 2.789 2.966 – 10.234 * 1.810 – 468.790 2.459 – 4.549 1.625 – 12.937 1.324 – 1.898 0.241 – 0.312 * 0.136 – 0.647 2.832 – 4.668 * 0.081 – 0.132 0.166 – 0.288 1.909 4.394 2.495 2.998 3.137 3.141 1.573 N/A 0.275 12.738 0.428 3.523 20.428 0.104 0.208 IMIDACLOPRID Michigan populations Montcalm Paul Main H6 Paul Main R13 Sackett Potatoes 14 Sackett Potatoes 132 Sackett Potatoes 152-153 Sackett Ranch VG1-2-7 St. Joseph Sturgis Tuscola Out-of-state populations Bridgewater, Maine Fryeburg, Maine Jamesport, New York Painter, Virginia Laboratory strain New Jersey THIAMETHOXAM Michigan populations Montcalm Paul Main H6 Paul Main R13 Sackett Potatoes 14 Sackett Potatoes 132 Sackett Potatoes 152-153 Sackett Ranch VG1-2-7 St. Joseph Sturgis Tuscola Out-of-state populations Bridgewater, Maine Fryeburg, Maine Jamesport, New York New Church, Virginia Laboratory strain New Jersey 3.248 0.872 0.671 0.960 0.859 0.691 0.773 0.152 0.253 1.304 0.134 0.730 1.152 0.884 0.112 1.552 – 411.562 0.753 – 1.014 0.321 – 262.123 0.670 – 4.686 0.498 – 2.478 0.608 – 0.780 0.687 – 0.871 0.122 – 0.180 0.174 – 0.347 1.038 – 1.956 0.087 – 0.177 0.324 – 1.281 1.011 – 1.324 * 0.098 – 0.130 * no confidence limits calculated due to insufficient fit to the model  98 A. B. Figure 1. thiameth to the sus  Susceptibilit oxam (B). D sceptible stra ty of field po Dark bars rep ain. opulations of present popu f Colorado po ulations that otato beetle t had significa to imidaclopr antly greater rid (A) and r LD50 valuess compared 99 Funding MPIC and Industry Evaluation of fungicide programs for potato early blight, brown leaf spot and tan spot control: 2010. W. W. Kirk, R. L Schafer and P. Tumbalam Department of Plant Pathology, Michigan State University, East Lansing, MI 48824 Potatoes (cut seed, treated with Maxim FS at 0.16 fl oz/cwt) were planted at Michigan State University Horticultural Experimental Station, Clarksville, MI (Capac loam soil); 42.8733, -85.2604 deg; elevation 895 ft. on 21 May into two-row by 20-ft plots (ca. 10-in between plants to give a target population of 50 plants at 34-in row spacing) replicated four times in a randomized complete block design. Plots were irrigated as needed with sprinklers and were hilled immediately before sprays began. All fungicides in this trial were applied on a 7-day interval from 23 Jun to 17 Aug (8 applications) with an ATV rear-mounted R&D spray boom calibrated to deliver 25 gal/A (80 p.s.i.) using three XR11003VS nozzles per row. Potato late blight was prevented from movement into the plots from adjacent plots inoculated with Phytophthora infestans with weekly applications of Previcur Flex at 1.2 pt/A from early canopy closure on 2 Jul to 24 Aug. Weeds were controlled by hilling and with Dual 8E (2 pt/A on 3 Jun), Basagran (2 pt/A on 28 Jun and 11 Jul) and Poast (1.5 pt/A on 11 Jul). Insects were controlled with Admire 2F (20 fl oz/A at planting), Sevin 80S (1.25 lb/A on 11 and 25 Jul), Thiodan 3EC (2.33 pt/A on 1 and 21 Aug) and Pounce 3.2EC (8 oz/A on 11 Jul). Plots were rated visually for combined percentage foliar area affected by early blight and brown leaf spot on 1 Sep [15days after final application (DAFA)]; and Botrytis tan spot on 1 Sep. Vines were killed with Reglone 2EC (1 pt/A on 6 Sep). Plots (2 x 25-ft row) were harvested on 5 Oct and tubers from individual treatments were weighed and graded. Meteorological variables were measured with a Campbell weather station located at the farm from 1 May to harvest (5 Oct). Maximum, minimum and average daily air temperature (oF) were 89.4, 28.8 and 59.7 (May); 86.3, 45.4 and 66.9 (Jun); 90.2, 46.4 and 73.1 and 1-d with maximum temperature >90oF (Jul); 90.6, 46.8 and 71.9 and 2-d with maximum temperature >90oF (Aug); 85.7, 40.2 and 60.1 (Sep); 85.7, 31.0 and 53.4 (to 5 Oct). Maximum, minimum and average relative humidity (%) was 93, 43 and 65 (May); 91, 55 and 73 (Jun); 91, 61 and 81 (Jul); 98, 34 and 72 (Aug); 99, 31 and 73 (Sep); 99, 19 and 69 (to 5 Oct). Maximum, minimum and average daily soil temperature (oF) were 77.8, 53.1 and 66.5 (May); 89.2, 54.6 and 74.0 (Jun); 94.5, 59.8 and 76.7 (Jul); 89.2, 65.2 and 78.5 (Aug); 86.9, 65.7 and 76.8 (Sep); 78.2, 56.6 and 64.9 (to 5 Oct). Maximum, minimum and average soil moisture (% of field capacity) was 38.4, 28.8 and 31.7 (May); 39.9, 32.3 and 34.7 (Jun); 38.6, 34.1 and 35.4 (Jul); 39.5, 32.9 and 35.2 (Aug); 42.0, 31.3 and 34.5 (Sep) and 42.0, 33.4 and 34.2 (to 5 Oct). Precipitation was 3.82 in. (May), 4.48 in. (Jun), 4.33 in. (Jul), 1.4 in (Aug), 5.14 in. (Sep) and 0.7 in. (to 5 Oct). Plots were irrigated to supplement precipitation to about 0.1 in./A/4 day period with overhead sprinkle irrigation. Early blight severity values accumulated from planting to 1 Sep (evaluation date) were 3475. Weather conditions were conducive for the development of early blight and brown leaf spot and Botrytis tan spot. Early blight and brown leaf spot developed steadily during Aug and untreated controls reached about 46% foliar infection by 1 Sep. All treatments had significantly less combined early blight and brown leaf spot than the untreated control. All fungicide programs had significantly less foliar tan spot values than the untreated control (36.3%). Treatments with greater than US1 yield of 178 cwt/A and total yield of 310 cwt/A were significantly different from the untreated control. Phytotoxicity was not noted in any of the treatments. 100 Funding MPIC and Industry Table 1. Efficacy of fungicide programs against foliar leaf spots of potatoes Yield (cwt/A) Foliar Botrytis Tan Spot (%) 1 Sep Foliar Early Blight + Brown Leaf Spot (%) 1 Sep 15 (DAFAz) 5.0 c US1 220 a ab cd 1.3 d 5.5 bc 3.0 cd 5.3 bc 6.3 bc 6.3 bc 6.3 bc 5.0 bc 215 164 6.3 bcx 188 abc (15 DAFA) 173 bcd Treatment and rate/A Dithane Rainshield 75DF 2 lb (A,Dy); Reason 500SC 4 fl oz + Dithane Rainshield 75DF 2 lb (B); Scala 606SC 7 fl oz + Dithane Rainshield 75DF 2 lb (C,E,F).. LEM17 200EC 12 fl oz (A,C,E,G,I); Tanos 50WG 6 oz + Manzate 75WG 1.5 lb (B,D,F,H,I)…….. LEM17 200EC 16 fl oz (A,C,E,G,I); Tanos 50WG 6 oz + Manzate 75WG 1.5 lb (B,D,F,H,I)…….. LEM17 200EC 24 fl oz (A,C,E,G,I); Tanos 50WG 6 oz + Manzate 75WG 1.5 lb (B,D,F,H,I)…….. Endura 7WG 2.5 oz (A,C,E,G,I); Tanos 50WG 6 oz + Manzate 75WG 1.5 lb (B,D,F,H,)….…... Echo ZN 4.17SC 2.12 pt (A,C,E,I); Endura 7WG 6 oz + Echo ZN 4.17SC 1.5 pt (B,F); Headline 2.09EC 2.5 oz + Echo ZN 4.17SC 1.5 pt (D); Dithane Rainshield 75DF 2 lb + Super Tin 80WP 2.5 oz (G,H)………………………………... Echo ZN 4.17SC 2.12 pt (A,C,E,I); BAS703 01F 4.17SC 4.1 fl oz + Echo ZN 4.17SC 1.5 pt (B,D,F); Dithane Rainshield 75DF 2 lb + Super Tin 80WP 2.5 oz (G,H)………………………………... SA-0011401 50SC 2.8 pt (A-I)………………………………. SA-0011401 50SC 2.1 pt (A-I)………………………………. Echo ZN 4.17SC 2 pt (A,C,E,I); Luna 500SC 6.84 fl oz (B,D,F); Dithane Rainshield 75DF 2 lb + Super Tin 80WP 2.5 oz (G,H)………………………………... Untreated……………………………………………………... LSD0.05 z Days after final application of fungicide. y Application dates: A= 23 Jun; B= 30 Jun; C= 7 Jul; D= 14 Jul; E= 21 Jul; F= 28 Jul; G= 4 Aug; H= 11 Aug; I= 17 Aug. x Values followed by the same letter are not significantly different at p = 0.05 (Fishers LSD). 7.5 b 23.8 a 3.42 c 5.0 5.0 c 10.0 b 175 bcd 219 197 a abc 3.0 cd 1.3 d 7.5 b 5.0 46.3 4.18 abc 188 142 d 178 a-d 42.7 6.0 bc 5.0 bc c a Total 286 abc 331 333 234 a a c 259 bc 297 ab 296 317 308 ab a ab ab 310 261 bc 55.0 101 Population characterization of P. infestans in Michigan during 2008 to 2010 Rojas A.1, Kirk W.W. 1 1 Department of Plant Pathology, Michigan State University, East Lansing, MI, USA. Introduction Phytophthora infestans (Mont.) de Bary, the causal agent of potato late blight is still a devastating pathogen even after 150 years since the Irish potato famine. Late blight mainly affects potato foliage, but can also significantly affect the tubers and indeed the tubers play a major role in the disease cycle of this pathogen. Potato late blight threatens potato production worldwide, which represents around 323 million tones, equivalent to 40 billion dollars of world production (FAO, 2008). The disease appears year after year causing from low effects to important epidemics like late blight epidemic in eastern USA in 2009. In Michigan, growers rate late blight as the most important disease of the potato crop (Zsofia Szendrei, pers. comm.) with a total planted area of 18,000 ha. Late blight is considered a re-emergent disease and its causal agent has been broadly studied to understand the infection process at different levels in order to develop effective management of the disease. Population analyses have become more important as aids to understanding the epidemiology, disease progression and the biology of the pathogen and have generally indicated that the population is volatile. In order to characterize the population, different tests based on phenotypic and genotypic traits, such as allelozymes, fungicide resistance, foliar virulence, nuclear DNA fingerprinting, mitochondrial haplotype (Fry, 2008) have contributed to understanding the dynamics of this pathogen. The complex genetics of Phytophthora infestans limited the applicability of these techniques because of their reduced resolution that lead to the underestimation of the variability of the population, thus the requirement of multiple traits or markers to overcome this issue (Fry and Goodwin, 1997). Although, other approaches should be considered to effectively track the population dynamics, single sequence repeats (SSR) have been successfully used to monitor late blight populations in Europe and China (Guo et al., 2009, Knapova and Gisi, 2002). SSR are powerful genetic markers, which are used to analyze population structure over time, in this case in epidemiological framework. In this study, we propose to use SSR as genetic markers to monitor Phytophthora infestans outbreaks through Michigan in conjunction with classical methods such as isozyme profile, virulence, mating type, among others (Cooke and Lees, 2004). Methods Isolate sources and maintenance Isolates were recovered from infected leaves, stems, fruits and tubers with visible symptoms of late blight from potato and tomato producing regions in Michigan during 2009 and 2010. The samples were from commercial fields, home gardens or research plots. Samples were place in plastic bags and stored at low temperature before processing. Isolates were obtained from fresh sporangia produced on the tissue and transferred to Rye B media (Caten and Jinks, 1968) amended with ampicillin (100 mg/ml), nystatin (100 mg/ml), rifampicin (50 mg/ml). If the tissue did not present sporulation, it was placed in a humid chamber at 18˚C for 24 to 72 hours to 102 induce sporulation. Plates were incubated in the dark at 18˚C until mycelia was observed. Hyphal tipping or single spore was assessed in clean cultures, if contamination was observed, transfers were made on clean-up media (Forbes, 1997). After isolation, cultures were grown and maintained on rye media. Mating type determination Mating type was determined in V8 agar transferring 5mm mycelial plugs of the unknown isolates and reference isolates A1 and A2 mating type. The plugs were placed 4 cm apart from each other. The plates were incubated at 18 ˚C for 14 days and evaluated for the presence or absence of oospores in the contact interface between the isolates and reference strains. Three replications were made for isolate. Isozyme analysis Genotype was established by isozyme analysis at glucose–6–phosphate isomerase (GPI) locus. Cellulose acetate gel electrophoresis (Helena Laboratories, Beaumont, TX) was done as reported by Goodwin et al. (Goodwin et al., 1995), resolving by overlay. Proteins were extracted from either fresh sporangia on leaf lesion or 10 days old pure cultures by grinding in sterile distilled water. Supernatants were recovered by centrifugation and stored at –20 ˚C prior to use. Five control isolates were used, representing the genotypes US–1, US–8, US-10, US–11 and US-14. Sensitivity metalaxyl Isolates sensitivity to the phenylamide fungicide metalaxyl was determined by transfer of mycelial plugs (5 mm diameter) into rye media amended with 0, 0.1, 1, 5, 10, 100 mg/L of active ingredient of metalaxyl fungicide (Ridomil Gold SL; Syngenta Crop Protection, Inc., Greensboro, NC). Plates were incubated at dark at 18 ˚C. Three replications were made for each isolate. Colony diameter were measured at 7, 10, 14 days after inoculation. Isolates were sensitive, intermediate, and resistance if the growth was < 10, 10 – 60, >60 % in comparison to control plate (Shattock, 1988). In addition, relative growth of each isolate (defined as isolate growth divided by growth of the non–amended control) was plotted against the log10 of the metalaxyl concentration. The effective concentration (EC50) for each isolate was calculated by regression analysis. The point on the regression line at which 50% of the isolate growth was inhibited is the EC50 value. Statistical analysis was conducted with the JMP program version 7.0 (SAS Institute Inc., SAS Campus Drive, Cary, North Carolina 27513, USA). Virulence test Each isolate was challenged against a R-gene differential set of potato clones, each carrying a single resistance gene (R1 – R11), in order to determine virulence and race of P. infestans isolates (Malcolmson and Black, 1966). Four detached leaflets of each differential were placed abaxial side up in moist chambers and inoculated with 20 !L of sporangial suspension (aprox. 20 000 sporangia mL-1) of each isolate. The leaflets were incubated in growth chambers at 18 ˚C, 85% relative humidity and 14 h light. Seven days after inoculation, leaflets were evaluated for presence of sporulation and rated as compatible or incompatible (Flier and Turkensteen, 1999). 103 Tuber pathogenicity Tuber late blight was assessed for all P. infestans isolates on the variety Red Northland. All tubers were washed in distilled H2O to remove soil. The tubers were then surface sterilized by soaking in 2% sodium hypochlorite solution for 30 min. Tubers were dried at room temperature. The washed, surface-sterilized tubers were inoculated by a insertion of mycelial plug (5 mm diameter) at the apical end of the tuber about 1 cm maximum depth. Fiver tubers were inoculated with each P. infestans isolates and five control tubers were inoculated with non- inoculated rye media. After inoculation, tubers were placed in the dark in sterilized covered plastic crates and returned to controlled environment chambers [Percival Incubator (Model I- 36LLVL, Geneva Scientific, LLC, PO Box 408, Fontana, WI)]. The chambers were set at 10oC and 95% humidity and the sample tubers were incubated for 30 days until evaluation. A digital image analysis technique was used to assess tuber tissue infection. The method was previously used and standardized (Kirk et al., 2001, Kirk et al., 1999). The image files were analyzed using SigmaScan V3.0 (Jandel Scientific, San Rafael, CA). The area selection cut-off threshold was set to 40 light intensity units, limiting the determination to the non–dark parts of the image. The average reflective intensity (ARI) of all the pixels within the image gave a measurement of infection severity of the tuber tissue of each sample. The ARI was measured in sections from the apical, middle and basal regions of the tuber. The amount of late blight infected tissue per tuber was expressed as a single value (Mean ARI) calculated as the average ARI of the apical, middle and basal sections evaluated 30 days after inoculation (DAI). The severity of tuber tissue infection was expressed relative to the ARI (described above) of the control tubers for each cultivar/ABL. The relative ARI (RARI) has minimum value of zero (no symptoms) and maximum value of hundred (completely dark tuber surface). Data for all experiments were analyzed by analysis of variance (least squares method) using the JMP program version 7.0 (SAS Institute Inc., SAS Campus Drive, Cary, North Carolina 27513, USA). DNA extraction Isolates were grown for 10 to 14 days at 18°C in clear pea broth or V8 broth (Forbes, 1997). The mycelium was filtered, lyophilized, and ground with a mortar and pestle. DNA was extracted according to method of Goodwin et al. (1992). DNA concentration and purity were estimated using a NanoDrop® ND-3300 fluorometer (NanoDrop Technologies, Wilmington, DE, USA). Mitochondrial haplotype Mitochondrial (mtDNA) haplotypes were determined by RFLP–PCR (Griffith and Shaw, 1998). All isolates were analyzed for mitochondrial haplotypes using the following primer pairs for specific mitochondrial DNA regions: P2 and P4, using the primers P2F 5"- TTCCCTTTGTCCTCTACCGAT-3", P2R 5"-TTACGGCGGTTTAGCACATACA-3", P4F 5"- TGGTCATCCAGAGGTTTATGTT-3" and P4R 5"-CCGATACCGATACCAGCACCAA-3", respectively. PCR was carried out as follows for all primer combinations in a final volume of 25 µl: 1# PCR buffer, 0.5 mM dNTPs (each), 2.5 mM MgCl2, 0.2 mM each primer, and 0.2 µl of Taq DNA polymerase (5 U/µl). The PCR conditions were 1 cycle of 94°C for 4 min and 35 cycles of 94°C for 60 s, 60°C for 45 s, and 72°C for 120 s. PCR products for region P2 and P4 were digested with the restriction enzymes MspI and EcoRI, respectively. The digestion products 104 were separated on 2% agarose gels and visualized by staining with ethidium bromide (Griffith and Shaw, 1998). Microsatellite Analysis Eight polymorphic microsatellite loci were chosen for analysis. Markers used were Pi4B, Pi4G and PiG11 (Knapova and Gisi, 2002) and Pi04, Pi16, Pi33, Pi56 and Pi70 (Lees et al., 2006), sequences are given in table 1. Microsatellite polymerase reactions were performed in a 25-µl reaction volumes. Each reaction tube contained 1# PCR buffer; 0.2 mM (each) of dNTPs, 1 mM MgCl2, 0.2 mM each forward and reverse primers, and 0.2 µl of Taq (5 U/ml). The thermal cycling parameters were initial denaturation at 94°C for 2 min followed by 35 cycles consisting of denaturation at 94°C for 1 min, annealing at 56°C for 45 s, and extension at 72°C for 2 min. A final extension at 72°C for 7 min was done at the end of the amplification. PCR products were examined by agarose gel electrophoresis using 3% (wt/vol) Metaphor agarose (FMC, Rockland, Maine), containing 0.5 !g/mL ethidium bromide, and the remainder was stored at 4 ˚C for later use. The electrophoretic buffer was 0.5X TBE (89 mmol/L Tris–HCl, pH 7.8; 89 mmol/L boric acid, 2 mmol/L EDTA). After electrophoresis at 98 V for 1.5 h, the image was acquired using the Bio-Rad ChemiDoc XRS imaging system (Bio-Rad, Hercules, CA, USA). Results and Discussion Sample collection From 2008 to 2010, potato and tomato symptomatic samples were obtained from growers of different regions of Michigan (Figure 1). A total of 115 isolates were obtained, most of them isolated from blighted stems and foliage, but a few isolates were isolated directly from blighted tubers. Samples from Alaska and Idaho were also obtained and few isolates were isolated to be included in the study as reference isolates. Both samples were blighted potato leaves and tubers. However, for analysis purposes the isolates were divided in two groups: (i) Isolates obtained from 2008 to 2009 and (ii) isolates obtained during 2010. Figure 1. Locations of fields from which isolates of Phytophthora infestans were obtained between 2008 - 2010. 105 Mating type and sensitivity to Metalaxyl Isolates were evaluated for mating type by two means: oospore production by testing with mating type reference isolates and molecular standard assay of the cleaved amplified region described by Judelson et al. (1995). Only one isolate was identified as A1, and it was isolated from tomato; the rest of the population is A2, which is the common mating type in US in the recent years. Metalaxyl in vitro assays on amended media showed different proportions for sensitive, intermediate and resistance isolates from 2008 to 2010. The distribution of isolates for both periods shows a transition from susceptible isolates in 2008-09 to a more homogeneous distribution 2010. In 2008-09, the EC50 values ranged from <0.1 to 52 !g/mL, where 26% of the isolates corresponded to susceptible, 61% were intermediate and 11% were resistant. For 2010, the EC50 values ranged from <0.1 to 91 !g/mL, 45% of the isolates corresponded to sensitive, 50% were classified as intermediate and 4% were resistant (Figure 2a). There is not significant difference between the observed frequencies for both periods, but there is a trend for metalaxyl responses in the population (Figure 2b). There was no association with host or location for metalaxyl resistance. However, 2 out 6 counties had resistant isolates in low frequencies. The rest of isolates from all the counties were sensitive to intermediate to metalaxyl. 106 Figure 2. (a) Range of EC50 (!g/mL) obtained during 2008-09 and 2010. (b) Histogram of log-EC50 (!g/mL) of populations of P. infestans during 2008-09 and 2010. Trend lines were plotted as regression analysis using polynomial equations. 107 Mitochondrial haplotype and isozyme analysis Two isozyme profiles, including 100/100/111 and 100/122 were found during the study for the GPI locus. However, clonal lineage US-8 and the new clonal lineage US-22 share bands in their profiles that can be misread during the analysis. The traditional US-8 profile was described as 100/111/122 is characterized by a five-band pattern, but it has been shown US-8 isolates that reduces to a three-band pattern by asexual variation. US-14 clonal lineage also possesses a three-band profile, resulting in 100/122. All isolates from 2010 were reported as 100/122, but it is necessary to fully review this result in conjunction with other markers. Mitochondrial DNA haplotypes Ia and IIa were found, but the most frequent haplotype was Ia (Figure 3). The mitochondrial haplotype Ia was the original mitochondrial haplotype found during Irish potato famine and it has been the common in the US. Figure 3. Mitochondrial haplotypes of P. infestans isolates in Michigan during 2008 to 2010. Virulence and Tuber Pathogenicity The virulence profile for the different isolates shows that at least every single R gene is present in the population in different frequencies. However, the existence of multiple combinations of this gene in one pathogen, denominated as a complex race, suggest the presence of isolates that can easily overcome resistance in the field. Isolates bearing 1 to 4 resistant genes were frequently isolated. The most frequent differentials were R3, R5 and R10 with frequencies close to 30% in the population. Late blight differential 9 was low, which is considered one the highly resistant genotypes. 108 Figure 4. Frequency of virulence for resistance genes in P. infestans isolates. On the other hand, potato pathogenicity among isolates from both periods evaluated ranged from low to moderate pathogenicity. Most of the isolates Relative Area Reflective Index (RARI) ranged form 5 to 30%. Either potato and tomato isolates were moderately pathogenic in tubers, showing values more than 20% RARI. Most isolates from 2010 that have been classified as US-22 clonal lineage showed variable tuber pathogenicity, but it is important to remark that many of them were isolated from tomato samples. Figure 5. Aggressiveness of different isolates of P. infestans collected during 2008 to 2010 tested in susceptible tubers cv. Red Norland. (RARI: Relative Area of Reflection Index). 109 Microsatellite Microsatellite or Single-Sequence Repeats (SSR) have recently been used to characterize P. infestans populations in Asia and Europe showing a diverse population, which could be suggested as a result of sexual recombination (Gisi et al., 2010, Guo et al., 2009). The application of this molecular markers in Michigan populations could give us an insight of how P. infestans populations in Michigan are behaving and also associate this markers to other traits relevant for epidemiology, such as pathogenicity or fungicide resistance. One of the markers that has been evaluated, The SSR G11 have shown the variability of the recent isolates obtained of P. infestans, where ‘old’ potato isolates just had one allele (160) and tomato isolates two alleles (160 and 156). The new clonal lineage US-22 was also characterized by the presence of these two alleles. Isolates collected in 2010 either from tomato or potato bore the two alleles, showing the shift in the population to new genotypes; only isolates from St. John (South West Michigan) showed the 160 allele. Other SSRs are under analysis to further characterize the composition of Michigan P. infestans populations. Figure 6. Single-sequence repeat genotyping of P. infestans isolates from Michigan during 2008 to 2010 using G11 marker. Conclusion Late blight caused by P. infestans have shown to be a devastating disease over the last decades, this is mainly caused by the ability of this pathogen to rapid evolve and overcome the different management strategies used in the field, such as fungicides and resistant varieties. Therefore, population studies are required to further characterize isolates affecting a specific 110 region, in order to develop effective solutions and trace how rapidly the pathogen is changing. New methodologies like SSRs have being applied in epidemiology to trace the origin of different isolates. Nonetheless, the fitness of the pathogen is important because it will determine if a specific genotype will remain in the population or not. For that reason, it is also important consider aggressiveness and pathogenicity of new clonal lineages because they can be related to specific markers, like SSRs, that can result in baseline evidence to analyze changes in the future epidemics. References Caten, C. & Jinks, J. (1968) Spontaneous variability of single isolates of Phytophthora infestans. I. Cultural variation. Can. J. Bot, 46:329-348. Cooke, D. & Lees, A. (2004) Markers, old and new, for examining Phytophthora infestans diversity. Plant Pathol., 53:692-704. FAO. Food and Agriculture Organization of the United Nations. FAOSTAT database. In., 2008. Flier, W. & Turkensteen, L. (1999) Foliar aggressiveness of Phytophthora infestans in three potato growing regions in the Netherlands. Eur. J. Plant Pathol., 105:381-388. Forbes, G. Manual for laboratory work on Phytophthora infestans, 1997. Fry, W. (2008) Phytophthora infestans: the plant (and R gene) destroyer. Mol. Plant Pathol., 9:385-402. Fry, W. & Goodwin, S. (1997) Re-emergence of potato and tomato late blight in the United States. Plant Dis., 81:1349-1357. Gisi, U., Walder, F., Resheat-Eini, Z., Edel, D. & Sierotzki, H. (2010) Changes of Genotype, Sensitivity and Aggressiveness in Phytophthora infestans Isolates Collected in European Countries in 1997, 2006 and 2007. J. Phytopathol.:no-no. Goodwin, S., Schneider, R. & Fry, W. (1995) Use of cellulose-acetate electrophoresis for rapid identification of allozyme genotypes of Phytophthora infestans. Plant Dis., 79:1181-1185. Griffith, G. & Shaw, D. (1998) Polymorphisms in Phytophthora infestans: Four mitochondrial haplotypes are detected after PCR amplification of DNA from pure cultures or from host lesions. Appl. Environ. Microbiol., 64:4007-4014. Guo, J., van der Lee, T., Qu, D., Yao, Y., Gong, X., et al. (2009) Phytophthora infestans isolates from Northern China show high virulence diversity but low genotypic diversity. Plant Biol., 11:57-67. Judelson, H. S., Spielman, L. J. & Shattock, R. C. (1995) Genetic mapping and non-Mendelian segregation of mating type loci in the oomycete, Phytophthora infestans. Genetics, 141:503-512. 111 Kirk, W., Niemira, B. & Stein, J. (2001) Influence of storage temperature on rate of potato tuber tissue infection caused by Phytophthora infestans (Mont.) de Bary estimated by digital image analysis. Pot. Res., 44:87-96. Kirk, W. W., Niemira, B. A., Stein, J. M. & Hammerschmidt, R. (1999) Late blight (Phytophthora infestans (Mont) De Bary) development from potato seed-pieces treated with fungicides. Pestic. Sci., 55:1151-1158. Knapova, G. & Gisi, U. (2002) Phenotypic and genotypic structure of Phytophthora infestans populations on potato and tomato in France and Switzerland. Plant Pathol., 51:641-653. Lees, A., Wattier, R., Shaw, D., Sullivan, L., Williams, N., et al. (2006) Novel microsatellite markers for the analysis of Phytophthora infestans populations. Plant Pathol., 55:311- 319. Malcolmson, J. & Black, W. (1966) New R genes in Solanum demissum lindl. and their complementary races of Phytophthora infestans (Mont.) de Bary. Euphytica, 15:199-203. Shattock, R. (1988) Studies on the inheritance of resistance to metalaxyl in Phytophthora infestans. Plant Pathol., 37:4-11. 112 Funding: MPIC and Industry Evaluation of fungicide programs for potato late blight control: 2010. W. W. Kirk, R. L Schafer, A. Rojas and P. Tumbalam, Department of Plant Pathology, Michigan State University, East Lansing, MI 48824 Potatoes (cut seed, treated with Maxim FS at 0.16 fl oz/cwt) were planted at Michigan State University Horticultural Experimental Station, Clarksville, MI (Capac loam soil); 42.8733, -85.2604 deg; elevation 895 ft. on 21 May into two-row by 20-ft plots (ca. 10-in between plants to give a target population of 50 plants at 34-in row spacing) replicated four times in a randomized complete block design. Plots were irrigated as needed with sprinklers and were hilled immediately before sprays began. All rows were inoculated (3.4 fl oz/25-ft row) with a zoospore suspension of Phytophthora infestans [US-8 biotype (insensitive to mefenoxam, A2 mating type)] at 104 spores/fl oz on 28 Jul. All fungicides in this trial were applied on 7 day interval from 29 Jun to 18 Aug (8 applications) with an ATV rear- mounted R&D spray boom calibrated to deliver 25 gal/A (80 p.s.i.) using three XR11003VS nozzles per row. Weeds were controlled by hilling and with Dual 8E (2 pt/A on 3 Jun) and Poast (1.5 pt/A on 11 Jul). Insects were controlled with Admire 2F (20 fl oz/A at planting), Sevin 80S (1.25 lb/A on 11 and 25 Jul), Thiodan 3EC (2.33 pt/A on 1 and 21 Aug) and Pounce 3.2EC (8 oz/A on 11 Jul). Plots were rated visually for percentage foliar area affected by late blight on 17, 24 Aug and 1 Sep [20, 27 and 34 days after inoculation (DAI)] when there was about 100% foliar infection in the untreated plots. The relative area under the late blight disease progress curve was calculated for each treatment from the date of inoculation to 1 Sep, a period of 34 days. Vines were killed with Reglone 2EC (1 pt/A on 6 Sep). Plots (2 x 25-ft row) were harvested on 18 Oct and tubers from individual treatments were weighed,graded, and 50 tubers were evaluated for tuber blight. Samples of 50 tubers per plot were stored after harvest in the dark at 50oF and incidence of tuber late blight was evaluated after 20 days in storage (8 Nov). Meteorological variables were measured with a Campbell weather station located at the farm from 1 May to harvest (5 Oct). Maximum, minimum and average daily air temperature (oF) were 89.4, 28.8 and 59.7 (May); 86.3, 45.4 and 66.9 (Jun); 90.2, 46.4 and 73.1 and 1-d with maximum temperature >90oF (Jul); 90.6, 46.8 and 71.9 and 2-d with maximum temperature >90oF (Aug); 85.7, 40.2 and 60.1 (Sep); 85.7, 31.0 and 53.4 (to 5 Oct). Maximum, minimum and average relative humidity (%) was 93, 43 and 65 (May); 91, 55 and 73 (Jun); 91, 61 and 81 (Jul); 98, 34 and 72 (Aug); 99, 31 and 73 (Sep); 99, 19 and 69 (to 5 Oct). Maximum, minimum and average daily soil temperature (oF) were 77.8, 53.1 and 66.5 (May); 89.2, 54.6 and 74.0 (Jun); 94.5, 59.8 and 76.7 (Jul); 89.2, 65.2 and 78.5 (Aug); 86.9, 65.7 and 76.8 (Sep); 78.2, 56.6 and 64.9 (to 5 Oct). Maximum, minimum and average soil moisture (% of field capacity) was 38.4, 28.8 and 31.7 (May); 39.9, 32.3 and 34.7 (Jun); 38.6, 34.1 and 35.4 (Jul); 39.5, 32.9 and 35.2 (Aug); 42.0, 31.3 and 34.5 (Sep) and 42.0, 33.4 and 34.2 (to 5 Oct). Precipitation was 3.82 in. (May), 4.48 in. (Jun), 4.33 in. (Jul), 1.4 in (Aug), 5.14 in. (Sep) and 0.7 in. (to 5 Oct). Plots were irrigated to supplement precipitation to about 0.1 in./A/4 day period with overhead sprinkle irrigation. The total number of late blight disease severity values (DSV) over the disease development period from 28 Jul to 1 Sep was 55 using 90% ambient %RH as bases for DSV accumulation. Late blight developed steadily after inoculation and untreated controls reached on average 100% foliar infection by 1 Sep. Up to 24 Aug, all fungicide programs had significantly less foliar late blight than the untreated control. Programs with less 12.5% foliar late blight were most effective. Application programs that persisted beyond 4 Aug generally maintained the best foliar late blight control by 1 Sep. By 1 Sep, programs with greater than 93.8% foliar late blight were not significantly different form the untreated control. All other programs had significantly better foliar late blight than the untreated control and programs with 15 to 21.3% had the most effective foliar late blight control. All fungicide programs had significantly lower RAUDPC values in comparison to the untreated control (37.6). Programs with 113 Funding: MPIC and Industry RAUDPC values from 3.2 to 5.6 had the most effective late blight control over the season. At harvest, there were significant differences in the incidence of tuber late blight and treatments with less than 5.3% of tuber blight were significantly different from the untreated control. Some tubers had close to 0% incidence of tuber late blight at harvest. On the 8 Nov (20 days after harvest) the percent incidence of infected tubers from untreated plots was 11.8%. Several treatments had very low incidence of tuber blight and ranged from 1.3 to 3.0% in the most effective treatments. Treatments with greater than 9.3% incidence were not significantly different from the untreated check. There were no significant differences in US1 or total yield among treatments. Phytotoxicity was not noted in any of the treatments. 114 Funding: MPIC and Industry Foliar potato late blight 17 Aug 20 DAIz efu 1.5 24 Aug 27 DAI 6.5 gh 1 Sep 34DAI RAUDPCy 34 DAI 4.6 jkl Tuber blight (%)x 18 Oct 8 Nov 171 DAP 3.8 de Yield US1 228 Total 308 2.0 def 3.0 def 2.8 def 2.0 def 1.8 ef 2.3 def 3.0 def 276 266 243 240 230 260 260 370 371 331 313 310 356 356 2.8 def 246 360 2.3 def 262 369 2.8 10.8 def ab 9.3 b 12.5 2.0 6.8 a def c 271 267 257 253 274 293 358 381 335 355 384 384 2.5 def 294 403 1.3 4.3 f d 321 244 424 355 4.0 de 270 377 4.3 d ab a 10.8 11.8 2.31 241 243 229 61.3 328 345 332 72.0 hi hi ef de 0.3 g kl kl 3.2 l efg d 15.0 i 1.5 1.1 f 4.3 3.0 def ef gh gh h h 16.3 16.3 4.3 3.3 4.0 3.6 3.6 5.0 6.5 5.0 1.8 2.5 1.5 d-g 4.5 def 37.5 cd 9.8 ef 16.3 def 18.5 de 3.0 ef 0.8 fg 4.8 i-l 1.5 d-g 38.8 cd 10.7 e 1.8 d-g 41.3 c 16.3 def 20.0 ghi 1.3 efg 12.5 efg 6.3 gh 21.3 f-i 4.3 def 10.8 e 2.0 def 1.0 efg 1.5 d-g 20.0 ghi 28.8 ef 5.3 h-l 8.1 e-h 12.5 21.3 31.3 86.3 ef ef ef 150 DAPw 2.3 def Treatment and rate/A BravoWS 6SC 1.5 pt (A-Hv)……………... Gavel 75DF 2 lb (A,C,E,F); BravoWS 6SC 1.5 pt (B,D,G,H)………… Revus Top 4.17SC 7 fl oz (A,C,E,F); BravoWS 6SC 1.5 pt (B,D,G,H)………… Zampro 4.38SC 14 fl oz (A,C,E,F); BravoWS 6SC 1.5 pt (B,D,G,H)………… BravoWS 6SC 1.5 pt (A,C,E,F); Zampro 4.38SC 14 fl oz (B,D,G,H)…..… Tanos 50WG 2.75 oz (A,C,E,F); BravoWS 6SC 1.5 pt (B,D,G,H)………… Ranman 400SC 2.1 fl oz (A,C,E,F); Dithane 75DF 1.0 lb (B,D,G,H)……….… BravoWS 6SC 1.5 pt (A,C,E,F); Revus Top 4.17SC 7 fl oz (B,D,G,H)…… Regalia Max 20SC 2 pt + Tanos 50WG 6 oz (A,C); BravoWS 6SC 1.5 pt (B,D,F,H); Regalia Max 20SC 2 pt + Revus Top 4.17SC 7 fl oz (E,G)……………………… Tanos 50WG 6 oz (A,C); Regalia Max 20SC 2 pt + BravoWS 6SC 1.5 pt (B,D,F,H); Revus Top 4.17SC 7 fl oz (E,G)……………………………………… Tanos 50WG 6 oz (A,C); BravoWS 6SC 1.5 pt (B,D,F,H); Revus Top 4.17SC 7 fl oz (E,G)…………. CX-9030 100WG 0.5 lb (A-H)…………... CX-9030 100WG 0.5 lb + Cueva 100AL 4 pt (A-H)………………… CX-9080 100WP 1.0 lb + Kocide 3000 46.1WG 1.5 lb (A-H)……… SA-0011401 50SC 2.8 pt (A-H)…………. SA-0011401 50SC 2.1 pt (A-H)…………. BravoWS 6SC 1.0 pt (A,C,E); Ranman 3.33SC 2.08 fl oz + Penncozeb 4F 2 fl oz + NIS 4 fl oz (B,D,F)…………………….. BravoWS 6SC 1.5 pt (A,C,E); Ranman 3.33SC 2.73 fl oz + Penncozeb 4F 2.88 fl oz + NIS 4 fl oz (B,D,F)………………….. BravoWS 6SC 1.5 pt (A,B,C); Ranman 3.33SC 2.73 fl oz + NIS 4 fl oz (D,E,F)…. BravoWS 6SC 1.5 pt + Ranman 3.33SC 2.08 fl oz (A,B,C); Gavel 75DF 2 lb (D); Ranman 3.33SC 2.73 fl oz + Penncozeb 4F 2.88 fl oz + NIS 4 fl oz (E,F)…………. BravoWS 6SC 1.5 pt + Ranman 3.33SC 2.08 fl oz (A,B); Gavel 75DF 2 lb (C); Ranman 3.33SC 2.73 fl oz + Penncozeb 4F 2.88 fl oz + NIS 4 fl oz (D,E,F)………. Oxidate 27SC 2 pt + Kocide 3000 46.1WG 1.5 lb (A-H)………. Untreated Check………………………….. LSD0.05 z Days after inoculation of Phytophthora infestans on 28 Jul. y RAUDPC, relative area under the disease progress curve calculated from day of appearance of initial symptoms. x Incidence of tuber late blight at harvest and after storage for 20 days at 50oF. w Days after planting. v Application dates: A= 29 Jun; B= 7 Jul; C= 14 Jul; D= 21 Jul; E= 28 Jul; F= 4 Aug; G= 11 Aug; H= 18 Aug. u Values followed by the same letter are not significantly different at p = 0.05 (Fishers LSD). 93.8 100 8.70 43.8 71.3 8.24 28.5 37.6 3.03 5.3 6.8 1.64 17.5 22.5 3.96 93.8 23.8 27.5 21.0 5.6 8.1 21.3 9.0 12.5 11.5 1.5 4.8 d fgh efg c g-l e-h ab e-h efg c ef def ab efg cd 5.3 1.0 3.0 8.4 16.9 4.3 bc 6.5 g-k 5.0 gh 2.5 de 21.7 c 41.3 c 7.5 f-i 30.0 c 37.5 cd 95.0 a 2.8 ef 40.0 c 7.2 f-j 1.5 d-g 1.8 d-g 3.3 ef 2.3 ef 2.0 def 2.8 ef 6.5 gh 2.5 de 7.7 7.0 43.8 45.0 1.5 4.8 d-g b 1.0 f 4.3 h efg d 3.3 h 4.0 h b a f-i f-j b a 7.5 d c c ab a de b b a ab a 115 Funding: MPIC and MSU GREEEN Effect of different genotypes of Phytophthora infestans (Mont. de Bary) and temperature on tuber disease development Kirk W.W., Rojas A.1, Tumbalam P.1, Gachango E.1, Wharton P.S. 1, Abu-El Samen F.1,, Douches, D.2, Coombs, J.2, Thill, C.A.3, Thompson, A.4 1 Department of Plant Pathology, Michigan State University, East Lansing, MI, USA. 2 Department of Crop and Soil Sciences, Michigan State University, East Lansing, MI, USA. 3 Department of Horticulture Science, University of Minnesota, St. Paul, MN, USA. 4 Plant Sciences Department, North Dakota State University, Fargo, ND, USA. Introduction Phytophthora infestans causes potato late blight in foliage and tubers and is a severe constraint on potato production. Late blight is readily transmitted by seed-borne inoculum and consequently, immature stems and leaves may be exposed to late blight from infected seed pieces (Kirk et al 2009). The transmission dynamics of late blight inoculum from seed to sprout and ultimately to the stem are still largely unknown and have been tested with only a limited number of varieties of potato and isolates of P. infestans. Direct loss of tuber yield occurs in the growing crop following reduction in photosynthetic capacity and tuber infection and also in the stored crop. Three major components contribute to late blight resistance in tubers; 1) a physical barrier consisting of several layers of phellem cells, known as the periderm; 2) the outer cortical cell layers that retard the growth of lesions and can completely block hyphal growth; and 3) medulla storage tissues characterized by reduced hyphal growth and sporulation of P. infestans (Flier et al. 1998; Flier et al. 2001; Pathak and Clarke 1987). Recent work has indicated that the new immigrant P. infestans clones, especially the US-8 genotype, are more aggressive in tubers and sprouts (Kirk et al. 2001; Lambert and Currier 1997). The dynamics of potato blight development in tubers are largely influenced by temperature (Kirk et al. 2001) and can result in decay in storage at currently used processing storage temperatures (e.g. 10oC for chip- processing) or non-emergence of plants due to seed and sprout rot (Kirk et al. 2009). The objective of this study was to use tubers from advanced breeding lines (ABL) and challenge them with different genotypes of P. infestans at three different temperatures used in storage (3, 7 and 10˚C) in four production seasons. These results showed the importance of different components involved in the disease development and inoculum source, including the pathogens variability. This study is an important approach to overcome aggressive P. infestans genotypes such as the US−8 genotype. Methods Tubers for this study were obtained from the potato breeding programmes at Michigan State University, the University of Wisconsin, the University of Minnesota and North Dakota State University. Potato tubers from cultivars/ABL harvested during the previous growing seasons were stored at 3oC in the dark at 90% relative humidity until used. Tubers were warmed to 15oC in incremental steps of 2oC for 7 d before inoculation. Tubers for the experiments were within the size grade range 50–150 mm diameter (any plane). Visual examination of a random sample of tubers from each entry for disease symptoms indicated that tubers were free from late blight. The sample was further tested with the ELISA immunodiagnostic Alert multiwell kit (Alert multiwell kit– Phytophthora sp., Neogen, Lansing, MI, USA). P. infestans was not detected in any of the tubers. Prior to inoculation, all tubers were washed with water to remove 116 Funding: MPIC and MSU GREEEN soil. The tubers were then surface-sterilized by soaking them in 2% sodium hypochlorite (Clorox) solution for 30 min. Tubers were dried in a controlled environment with continuous airflow at 15 °C in dry air (30% relative humidity) for 4 h prior to inoculation. Cultures of P. infestans isolates corresponding to clonal lineages US−1 (Pi95-3), US−1.7 [Pi88 (2002-06)], US-6 [Pi95-2 (2006-07)], US−8 [Pi02-007 (2002-05), Pi06-02 (2006-07)], US−10 [SR83-84 (2005-06), Banam AK (2006-07)], US−11 (Pi96-1), US−14 [Pi98-1 (2002-05), Pi00-001 (2006-07)] were selected based on the aggressiveness criteria (Young et al. 2009). The isolates were grown in rye B media for 14 days in the dark at 18oC for sporangia production, and transferred to the light for 2 days to encourage sporulation. Sporangia and mycelium were harvested by flooding with cold sterile water (4oC) and gentle scraping of the surface of the culture using a rubber policeman. The mycelium/sporangia suspension was stirred with a magnetic stirrer for 1 h. The suspension was strained through four layers of cheesecloth and sporangia concentration was measured with a hemacytometer and adjusted to about 1 x 106 total sporangia ml-1 (discharged and non-discharged). The sporangial suspensions were stored for 6 h at 4oC to encourage zoospore release from the sporangia. The washed, surface-sterilized tubers were inoculated by a sub-peridermal injection of a sporangia suspension of 2 x 10-5 ml (delivering zoospores released from about 20 sporangia inoculation-1) with a hypodermic syringe and needle at the apical end of the tuber about 1 cm from the dominant sprout to a maximum depth of 1 cm. Ten tubers of each cultivar/ABL were inoculated with each P. infestans genotype per temperature. Ten control tubers per cultivar/ABL were inoculated with cold (4oC) sterile distilled H2O. After inoculation, tubers were placed in the dark in sterilized covered plastic crates and returned to controlled environment chambers [Percival Incubator (Model I-36LLVL, Geneva Scientific, LLC, PO Box 408, Fontana, WI)]. The chambers were set at 3, 7 or 10oC and 95% humidity and the sample tubers were incubated for 40 days until evaluation. A digital image analysis technique was used to assess tuber tissue infection. The method was previously used and standardized (Kirk et al. 2001a; Niemira et al. 1999). The image files were analyzed using SigmaScan V3.0 (Jandel Scientific, San Rafael, CA). The amount of late blight infected tissue per tuber was expressed as a single value (Mean ARI) calculated as the average ARI of the apical, middle and basal sections. The severity of tuber tissue infection was expressed relative to the ARI (described above) of the control tubers for each cultivar/ABL. The relative ARI (RARI %) has minimum value of zero (no symptoms) and maximum value of hundred (completely dark tuber surface). Data for all experiments were analyzed by analysis of variance (least squares method) using the JMP program version 7.0 (SAS Institute Inc., SAS Campus Drive, Cary, North Carolina 27513, USA). 117 Funding: MPIC and MSU GREEEN Figure 1. Tuber late blight, as mean RARI (%), evaluated across cultivars and advanced breeding lines inoculated with different P. infestans genotypes. The analysis was developed on (a) 2003, (b) 2004, (c) 2005, (d) 2006 and (e) 2007. 118 Table 1. Effect of storage temperature on tuber tissue late blight as mean Relative Average Reflection Intensity [RARI (%)] in different cultivars and advanced breeding lines (ABL) of potatoes after inoculation with different genotypes of Phytophthora infestans by year. Funding: MPIC and MSU GREEEN a Normalized tuber tissue darkening score expressed as RARI (%) = [1- Mean ARI treatment / Mean ARI control ] *100; % RARI has a minimum value of zero (no darkening, but if the value is negative the tuber tissue was lighter than the control) and maximum value of 100 (cut tuber surface is completely blackened). The numbers are derived from the mean average reflective intensity of three surfaces cut latitudinal at 25, 50 and 75% from the apex of n = 10 tubers per treatment combination. b Values followed by the same letter are not significantly different at p = 0.05 for comparisons of mean RARI values within different P. infestans genotypes of cultivar/ABL combinations and temperature treatments (Based on Fishers protected LSD). 119 Results and Discussion Funding: MPIC and MSU GREEEN Different varieties/ABLs of potatoes showed a broad range of responses to the infection with different P. infestans genotypes for each year. Interaction between storage temperature, genotype aggressiveness and cultivar/ABL resistance were the different factors of interest in this experiment. Tuber late blight development measured as mean RARI (% Relative Average Reflective Intensity) over the range of factors (variety and temperature). Effect of different temperatures and genotypes of Phytophthora infestans on tuber disease development was evaluated by repeating the experiment for 5 consequent years. In most of the years, P. infestans genotype US – 8 caused most tuber rotting genotypes followed by US – 11 and US – 14 (Figure 1 and Table 1). Also, the storage conditions had a great effect on the disease development, affecting the tuber late blight development because of the survival of the inoculum at lower temperatures. Different storage temperatures (3, 7 and 10ºC) were used to evaluate tuber infection and late blight development. The disease rate was high at 10ºC for every year (Figure 2), consequently the response is affected by the other two factors: cultivar/ABL resistance and the aggressiveness of the P. infestans genotype. Late blight symptoms were also observed in 3ºC and 7ºC in different isolates and varieties. The results showed that US−8 genotype was the most aggressive, regardless of the variety or temperature (Table 1 and Figure 1, 2). Figure 2. Tuber late blight measured as mean RARI (%) for the different P. infestans genotypes across evaluated years. Among the different varieties and ABL’s, Jacqueline – Lee and Stirling were one of the most resistant varieties with mean RARI ranged from 2% to 4%. On the other hand, the most susceptible varieties were White Pearl and MSN 105-1, which had mean RARI values from 10% to 17%. 120 Conclusions Funding: MPIC and MSU GREEEN The mean RARI (%) is an excellent measure of tuber late blight disease and the range of RARI responses show that different P. infestans genotypes respond differently to host resistance and storage conditions. The most recently appeared genotypes of P. infestans produce severe symptoms in most cultivars/ABL to the different storage temperature conditions. The US – 8 genotype was consistently the most aggressive isolate causing high tuber discoloration and rotting. In addition, the aggressiveness of US−8 genotype increased with temperature, and the mean RARI (%) values were greater than in any other P. infestans genotypes. US−11 and US−14 genotypes caused less disease in tubers, and US−1 genotype being the least. References Flier, W.G., L.J. Turkensteen, and A. Mulder. 1998. Variation in tuber pathogenicity of Phytophthora infestans in the Netherlands. Potato Research 41: 345-354 Flier, W.G., L.J. Turkensteen, G.B.M. van den Bosch, P.F.G. Vereijken, and A. Mulder. 2001. Differential interaction of Phytophthora infestans of potato cultivars with different levels of blight resistance. Plant Pathology 50: 292-301 Kirk, W., Rojas, A., Tumbalam, P., Gachango, E., Wharton, P., El-Samen, F., Douches, D., Coombs, J., Thill, C., and Thompson, A. Effect of different genotypes of Phytophthora infestans (mont. de bary) and temperature on tuber disease development. Am. J. Pot. Res. DOI: 10.1007/s12230-010-9156-1 Kirk WW, Niemira BA and Stein JM (2001) Influence of storage temperature on rate of potato tuber tissue infection caused by Phytophthora infestans (Mont.) de Bary estimated by digital image analysis. Potato Res 44: 86-96 Kirk W, Abu-El Samen F, Tumbalam P, Wharton P, Douches D, et al. 2009. Impact of Different US Genotypes of Phytophthora infestans on Potato Seed Tuber Rot and Plant Emergence in a Range of Cultivars and Advanced Breeding Lines. Potato Res 52:121-40. Lambert, D.H., and A.I. Currier. 1997. Differences in tuber rot development for North American clones of Phytophthora infestans. American Potato Journal 74: 39-43. Niemira BA, Kirk WW and Stein JM (1999) Screening for late blight susceptibility in potato tubers by digital analysis of cut tuber surfaces. Plant Diseases 83: 469-473. Pathak, N., and D.D. Clarke. 1987. Studies on the resistance of the outer cortical tissues of the tubers of some potato cultivars to Phytophthora infestans. Physiol. Mol. Plant Pathol. 31: 123-32. Young GK, Cooke LR, Kirk WW, Tumbalam P, Perez FM, Deahl KL (2009) The influence of competition and host plant resistance on selection of Phytophthora infestans populations in Michigan State and Northern Ireland. Plant Pathol doi:10.1007/BF02986273 121 Evaluation of fungicide programs for Pythium leak control, 2010. W. W. Kirk, R. L Schafer and P. Tumbalam. Department of Plant Pathology, Michigan State University, East Lansing, MI 48824 Funding: MPIC and Industry Potatoes (cut seed, treated with Maxim FS at 0.16 fl oz/cwt) were planted at the Michigan State University Horticultural Experimental Station, Clarksville, MI (Capac loam soil); 42.8733, -85.2604 deg; elevation 895 ft. on 5 May into two-row by 25-ft plots (ca. 6-in between plants to give a target population of 100 plants at 34-in row spacing) replicated four times in a randomized complete block design. The trial area was inoculated with Pythium ultimum and Phytophthora erythroseptica-infected tubers from at a rate of about 400 cwt tubers/A. Plots were irrigated as needed with sprinklers and were hilled immediately before sprays began. In- furrow applications were applied with an R&D spray boom delivering 8 gal/A (80 p.s.i.) and using one XR11003VS nozzle per row. Foliar applications were applied with an ATV rear-mounted R&D spray boom calibrated to deliver 25 gal/A (80 p.s.i.) using three XR11003VS nozzles per row. Previcur Flex was applied at 0.7 pt/A on a seven-day interval, total of four applications, starting one day after inoculation of adjacent plots with Phytophthora infestans. Weeds were controlled by hilling and with Dual 8E (2 pt/A on 25 May), and Poast (1.5 pt/A on 11 Jul). Insects were controlled with Admire 2F (20 fl oz/A at planting), Sevin 80S (1.25 lb/A on 11 and 25 Jul), Thiodan 3EC (2.33 pt/A on 1 and 21 Aug) and Pounce 3.2EC (8 oz/A on 11 Jul). Emergence was rated up to 44 days after planting and final plant stand and relative rate of emergence (relative area under the emergence progress curve – RAUEPC) were evaluated. Vines were killed with Reglone 2EC (1 pt/A on 1 Oct). Plots (2 x 25- ft row) were harvested on 15 Oct and individual treatments were weighed and graded and tuber number in size grades US-1 and b-grade determined. Samples of four plants were collected at desiccation and harvest from each plot and the percentage of tubers with symptoms of Pythium leak evaluated. Yield samples from each plot (n = 50 tubers) were stored in the dark at 50oF and 95% RH for 21 days after harvest and the percentage of tubers with Pythium leak determined to give measurements of incidence. Meteorological variables were measured with a Campbell weather station located at the farm from 1 May to harvest (15 Oct. Meteorological variables were measured with a Campbell weather station located at the farm from 1 May to harvest (5 Oct). Maximum, minimum and average daily air temperature (oF) were 89.4, 28.8 and 59.7 (May); 86.3, 45.4 and 66.9 (Jun); 90.2, 46.4 and 73.1 and 1-d with maximum temperature >90oF (Jul); 90.6, 46.8 and 71.9 and 2-d with maximum temperature >90oF (Aug); 85.7, 40.2 and 60.1 (Sep); 85.7, 31.0 and 53.4 (to 5 Oct). Maximum, minimum and average relative humidity (%) was 93, 43 and 65 (May); 91, 55 and 73 (Jun); 91, 61 and 81 (Jul); 98, 34 and 72 (Aug); 99, 31 and 73 (Sep); 99, 19 and 69 (to 5 Oct). Maximum, minimum and average daily soil temperature (oF) were 77.8, 53.1 and 66.5 (May); 89.2, 54.6 and 74.0 (Jun); 94.5, 59.8 and 76.7 (Jul); 89.2, 65.2 and 78.5 (Aug); 86.9, 65.7 and 76.8 (Sep); 78.2, 56.6 and 64.9 (to 5 Oct). Maximum, minimum and average soil moisture (% of field capacity) was 38.4, 28.8 and 31.7 (May); 39.9, 32.3 and 34.7 (Jun); 38.6, 34.1 and 35.4 (Jul); 39.5, 32.9 and 35.2 (Aug); 42.0, 31.3 and 34.5 (Sep) and 42.0, 33.4 and 34.2 (to 5 Oct). Precipitation was 3.82 in. (May), 4.48 in. (Jun), 4.33 in. (Jul), 1.4 in (Aug), 5.14 in. (Sep) and 0.7 in. (to 5 Oct). Plots were irrigated to supplement precipitation to about 0.1 in./A/4 day period with overhead sprinkle irrigation. Pythium developed in the trial at moderate levels but the reduction in yield at harvest was likely due to loss of tubers to both pink rot and Pythium leak. Pink rot could be detected but Pythium leak overwhelmed infected tubers. Although some treatments had a significant effect on final plant stand no treatment had a final plant stand below 95%. The application of Phostrol at planting significantly increased the relative rate of emergence (RAUEPC) in comparison to the untreated control but no other treatments were different from the untreated control. All treatments had significantly lower incidence of Pythium incidence in comparison with the untreated in tubers at desiccation timing and 21 days after harvest but there was no difference among treatment at the harvest evaluation. All treatments had significantly higher marketable and total yield of tubers in comparison with the untreated (Table 1). 122 Table 1. Efficacy of soil applied fungicides against Pythium leak. Final plant stand 44 DAP RAUEPCz 0 – 44 DAP Max = 100 Pythium Leak Incidence (%)y At 21 days after Yield (cwt/A) 1.8b 96aw harvest US-1 Total 31.2ab 26.6de 24.1e 96a 97a 96a 0.0c 1.0bc 1.0bc 1.8b 1.5b 1.8b 1.8b Desiccation At harvest 1.3a 0.8a 1.8a 0.8a Treatment and rate/A or rate/1000 row ft Presidio 4SC 0.264 fl oz/1000 row ft (Ax); Presidio 4SC 0.264 fl oz/1000 row ft (B)………. Ranman 3.33SC 0.183 fl oz/1000 row ft (A); Ranman 3.33SC 2.75 fl oz/A (C)……………….. Ridomil Gold 4EC 0.42 fl oz 1000 row ft (A)….. Presidio 4SC 0.264 fl oz/1000 row ft + Ridomil Gold 4EC 0.42 fl oz 1000 row ft (A)… Ranman 3.33SC 0.183 fl oz/1000 row ft (A); Ranman 3.33SC 2.75 fl oz/A (B); Phostrol 53.6SC 1.25 gal/A (C)…………………. Phostrol 53.6SC 0.42 fl oz 1000 row ft (A); Phostrol 53.6SC 1.25 gal/A (B,C)………………. Untreated............................................................... LSD0.10 z RAUEPC, relative area under the emergence progress curve calculated from day of planting to 95% emergence in untreated check plots. y Incidence of pythium leak determined by tuber number. x Application dates: A= 5 May (in-furrow at planting per 1000 row ft); B= 9 Jun (hilling); C= 16 Jun (hooking, rate/A) w Values followed by the same letter are not significantly different at p = 0.10 (Fishers protected LSD). 232ab 152c 42.4 323a 233b 53.2 99a 99a 3.1 2.8b 6.0a 1.42 1.0a 3.3a 1.85 1.5b 3.3a 1.02 33.9a 28.8bcd 317a 312a 323a 300a 210ab 203ab 243a 218ab 27.2cde 0.8bc 3.67 30.7abc 0.5a 2.5b 199b 287a 98a 123     Funding:  MPIC     Fusarium Species Responsible for Dry Rot of Seed Potato Tubers in Michigan Esther Gachango, W. Kirk, L. Hanson, A. Rojas, and P. Tumbalam Department of Plant Pathology, Michigan State University, East Lansing, Michigan, USA Introduction Potato dry rot is a postharvest disease caused by several Fusarium species and is of worldwide importance (Secor and Salas, 2001). So far twelve species have been implicated in causing dry rot worldwide (Hide et al., 1992), and among them eight species have now been reported in northern united States (Hanson et al., 1996). The most prevalent species are, F. sambucinum Fuckel (=Fusarium sulphureum Schlechtend; teleomorph: Gibberella pulicaris (Fr.:Fr) Sacc.), F. solani (Mart.) Sacc. var. coeruleum (Lib. ex Sacc.) C. Booth (=F. coeruleum; teleomorph: Nectria haematococca Berk. & Broome), and F. oxysporum Schlechtend. Fr.(Hanson et al., 1996). In Michigan seed potato production, dry rot has been reported in most of the seed lots (Kirk and Wharton, 2008) and F. sambucinum is the most predominant species affecting potato in storage and causing seed piece decay after planting (Lacy and Hammerschmidt, 1993). However, there has been no assessment of composition of Fusarium species causing dry rot in Michigan. Materials and methods • Isolation: 260 dry rot symptomatic tubers were collected from seed lots in Michigan potato growing area in summer 2009. Small pieces were cut from the margins of the necrotic region with a sterile scalpel, surface-disinfected in 10% bleach solution for 10 s, rinsed twice in sterile distilled water, and blotted with sterile filter paper. The tissue pieces were then plated on half strength potato dextrose agar (PDA; Difco, Detroit, Michigan) amended with 0.5 g/L streptomycin sulfate. The Petri dishes were incubated at 23°C for 5 to 7 d. Cultures resembling Fusarium species were transferred onto water agar; hyphal tip transfer was done from the margin of actively growing isolates with a sterile probe and plated on carnation leaf agar (CLA) and half strength PDA to generate pure cultures. Pure cultures on CLA were identified based on conidial morphology and production of chlamydospores, while those on PDA were identified based on colony pigmentation. The species of each Fusarium isolate was determined using techniques described by Leslie et al. (2006). To confirm species identity, lyophilized mycelium from pure cultures grown on PDA were used for DNA extraction, followed by amplification and sequencing of the translation elongation factor (EF-1α) gene region. The Fusarium- ID.v (Geiser et al., 2004) and the NCBI database were used to obtain the closest match to previously sequenced materials. • Fungicide Sensitivity Testing: EC50 value, defined, as the concentration of fungicide that inhibited colony radius on PDA by 50% was determined for 169 isolates using the spiral gradient endpoint (SGE) method for thiabendazole (TBZ), fludioxonil and difenoconazole. This aimed at establishing baselines for future studies. Agar plates 15cm in diameter were prepared 48h before fungicide solutions were applied with a spiral plater using the exponential deposition mode. For all the fungicides, the stock 124     Funding:  MPIC     concentration was 10000ppm. The plates were incubated for 3h to allow fungicides to diffuse into the medium and form a gradient of concentrations along the radius of the plate. Conidial suspension (106 conidia/ml) per isolates was streaked across the radial lines guided by an SGE template placed under the plate. Three replicates per isolate were used. The plates were incubated at 25°C for 3 days, after which the radius of the mycelial growth was determined and used to calculate the EC50. • Pathogenicity Testing: All isolates obtained were tested for pathogenicity on disease-free potato tubers, cv. Red Norland. The tubers were surface sterilized for 10 min in 10% bleach solution and rinsed twice in distilled water. Three tubers per isolates were injected with 20µl of conidial suspension (106 conidia/ml) made from Fusarium cultures grown on PDA for 7 days. The tubers were incubated for 30 days at 10°C. Tubers were cut into half and any isolate that produced lesions on tuber surface was considered pathogenic. The tuber lesions were scanned and using the SigmaScan Pro 5 program, the area of the lesion was determined relative to the total area of the tuber surface to give the level of aggressiveness. Results and Discussion • A total of 169 Fusarium isolates (Fig 1) were recovered from the infected tubers. F. oxysporum, F. equiseti, and F. sambucinum were the most common species comprising 28.4, 23.6, and 14.4% of the isolates respectively. • F. avenaceum, F. solani, F. cerealis and F. acuminatum, were less common comprising 10.9, 9.9, 6.1, and 3.9% of the isolates respectively. • The other species identified were, F. sporotrichioides, F. torulosum, and F. tricinctum, all found in very low percentage. • All the Fusarium isolates recovered were pathogenic to potato tubers (Fig 1). • F. sambucinum was the most aggressive based on percentage of the infected area. Isolates of the same species depicted different levels of aggressiveness for F. sambucinum, F. avenaceum and F. acuminatum. • 125     Funding:  MPIC     Figure 1: Aggressiveness of Fusarium isolates on potato tubers (cv. Red Norland) inoculated with F. sambucinum, F. avenaceum, F. tricinctum, F. acuminatum, F. cerealis, F. sporotrichioides, F. solani, F. equiseti, F. oxysporum, F. torulosum respectively. • All isolates of F. sambucinum were resistant to TBZ with an EC50 greater than 136 mg/L. This also applied to the known TBZ-resistant isolates of F. sambucinum (R-09271 -Desjardins YG-1 U7200A). • However, the rest of the isolates as well as the known F. sambucinum-TBZ susceptible (R-00738, Cetas, R.C) were sensitive to TBZ with EC50 ranging from 0.9- 4.9 mg/L (Fig 2).   Figure 2: EC50 of TBZ against sensitive Fusarium isolates. R-00738= F. sambucinum TBZ susceptible   126     Funding:  MPIC     • All the Fusarium isolates were sensitive to difenoconazole with an EC50 ranging from 0.69-4.2 mg/L (Fig 3). Figure 3: EC50 of difenoconazole against different Fusarium isolates. R-00738 = F. sambucinum TBZ susceptible; R-09271= F. sambucinum TBZ –resistant • Both resistant (EC50>100mg/L) and sensitive isolates of F. sambucinum and F. oxysporum to fludioxonil were reported. • Fusarium isolates sensitive to fludioxonil had EC50 ranging from 0.8-4.9 mg/L (Fig 4). Figure 4:EC50 of fludioxonil against sensitive Fusarium isolates, R-00738 = F. sambucinum-TBZ susceptible, R-09271= F.sambucinum TBZ resistant   127     Funding:  MPIC     Conclusions • Ten Fusarium species are responsible for dry rot of potato in Michigan. • F. sambucinum is the most aggressive, although found in a lower frequency compared to F. oxysporum. • TBZ can still be used to control dry rot caused by other Fusarium species apart from TBZ resistant- F. sambucinum. • Difenoconazole can also be used to control Fusarium dry rot, while fludioxonil can only be used to control the sensitive isolates of F. sambucinum and F. oxysporum, or other Fusarium species causing dry rot • The baseline sensitivity levels can be used to determine sensitivity shifts in future. Reference Geiser, D., del Mar Jiménez-Gasco, M., Kang, S., Makalowska, I., Veeraraghavan, N., Ward, T., Zhang, N., Kuldau, G. & O'Donnell, K. (2004) Fusarium-ID v. 1.0: A DNA sequence database for identifying Fusarium. Eur J Plant Pathol, 110:473- 479. Hanson, L. E., Schwager, S. J. & Loria, R. (1996) Sensitivity to thiabendazole in Fusarium species associated with dry rot of potato. J Phytopathol, 86:378-384. Hide, G. A., Read, P. J. & Hall, S. M. (1992) Resistance to thiabendazole in Fusarium species isolated from potato tubers affected by dry rot. Plant Pathol, 41:745-748. Kirk, W. W. & Wharton, P. (2008). Fusarium dry rot posing problems in potatoes. Vegetable Crop Advisory Team Alert Retrieved July 23, 2010, from http://www.potatodiseases.org/pdf/Disease-update-2008-Fusarium-dry-rot.pdf Lacy, M. L. & Hammerschmidt, R. (1993). Fusarium dry rot. Retrieved May 23, 2010, from http://web1.msue.msu.edu/msue/iac/onlinepubs/pubs/E/E2448POT.PDF Leslie, J., Summerell, B. & Bullock, S. The Fusarium laboratory manual, Wiley- Blackwell, 2006. Secor, G. A. & Salas, B. Fusarium dry rot and Fusarium wilt. In: W.R. Stevenson., R. Loria., G.D Franc., a. & D.P. Weingartner (eds), Compendium of Potato Diseases. St. Paul, MN, American Phytopathological Society Press, 2001, pp. 23-25. 128 2010 Research Report to MPIC Research Committee PROJECT TITLE: Managing potato common scab using biomaterials and beneficial Jianjun Hao, William Kirk, David Douches, Qingxiao Meng, and Noah Rosenzweig microorganisms STATEMENT Potato common scab (PCS) continues to be a threat to the Michigan potato industry, due to the lack effective control methods. The disease suppressive soil that we have identified is a valuable resource for basic study and ultimately improved management of potato common scab. Understanding the suppressiveness phenomenon will also help to understand the interaction between plant host and the major PCS pathogen, and help clarify the interactions between the pathogen and other microorganisms in the soil. Moreover, we continued to study promising biomaterials, such as plant extracts, and beneficial microorganisms to reduce PCS in greenhouse conditions with the eventual goal of effective in-field deployment. 1. Diversity of pathogenic Streptomyces species in Michigan To investigate the diversity of Streptomyces spp. in major potato production areas, soil samples were collected and Streptomyces was isolated. By comparing the 16S rRNA gene sequences, and BOX-PCR, it is the first confirmed report of S. stelliscabiei in Michigan (Figure 1). This information expands the knowledge of pathogen diversity in Michigan in addition to DS3024 (previously reported). 2. Characterization soil microbial community of common scab suppressive soil using pyrosequencing Pyrosequencing is a new more comprehensive high-throughput DNA sequencing technology (next generation sequencing) capable of a greater depth of detection of soil organisms. Soil was collected from the disease suppressive and conducive soils. Total DNA was extracted from the soil using a DNA extraction kit. The ribosome considered the workhorse of protein synthesis in the cell offers an ideal target (16S rRNA gene) for DNA characterization of microbes in the environment. A pyrosequencing-based approach was used to analyze amplicon libraries from polymerase chain reaction (PCR) amplification of the phylogenetically informative 16S rRNA gene region (variable across taxa). The resulting bacterial 16S/mycorrhizal 18S rDNA sequences will eventually be deposited in the GenBank Short Read Archive. Data were analyzed using an operational taxonomic unit (OTU)-based and a taxon-based approach to determine microbial community composition (e.g. pathogens and beneficial microbes). Additionally indicator taxon analysis and richness estimates of bacterial sequences originating from different samples will be determined. OTU analyses will be performed using various computer software packages. Results showed that one third of the soil microbial community inhabitants are shared between disease suppressive and conducive soils (Figure 1). Disease suppressive soil had significantly higher populations of pseudomonads, Lysobacter, and Rhodanobacter, which are all groups of bacteria considered beneficial microorganisms or having antagonistic activities.       129 Hao 2010 Report to MPIC Streptomyces spp., including pathogenic and nonpathogenic types, were found to be at similar levels for both soil types. Interestingly, Bacillus spp. was much lower in the disease suppressive soil (Table 1). Based on the current data and previous results, it is most likely that bacteria such as florescent pseudomonads and lysobacter, play important roles for suppressing pathogens in soil. 3. Management of potato common scab using biological and plant-derived products In the greenhouse, several products for the control of potato common scab will be evaluated. Products include i) biological control agents, Bacillus spp. (BAC1 to 3), Telnet (Trichoderma asperellum & T. gamsii, SipCam Advan); ii) disease resistance inducer, Regalia ® (giant knotweed extract, Marrone Organic); iii) soil amendments, chestnut shells; and iv) the chemical PCNB. In the field, materials BAC03, Regalia, chestnut amendment, chicken manure, Tenet, and PCNB will be applied for potato common scab control. This will be conducted at Montcalm and Michigan State University, with a randomized complete block design with four replications. All the products except Regalia will be applied in-furrow, immediately followed by planting potato seed tubers. Regalia will be sprayed on the foliage after seedling emergence. At harvest, potato tubers will be evaluated for yield, and disease severity. Data will be analyzed using SAS statistical package. Chestnut extracts from shell, leaf, and pellicle had antimicrobial activity against a broad range of microorganisms, and pellicle had the highest concentration of antimicrobial compounds. All the test pathogenic Streptomyces spp. were sensitive to the extract and had lower effective concentration for 50% growth inhibition (ED50) (Table 2). In the greenhouse, chestnut tissue incorporated in potting soil significantly reduced the disease intensity of scab symptoms in both potato and radish (Figure 3). There was a linear or curve linear relationship between the application rate of chestnut tissue and disease reduction; higher application rates resulted in less disease, vise versa (Figure 3). Bacillus spp. isolated from the disease suppressive soil was positively correlated to a reduction in scab disease. In the greenhouse, when soil was treated with strains of Bacillus spp., radish biomass or weight was significantly higher (Figure 4) and disease intensity (Figure 5) was lower than that treated with PCNB (the standard chemical for scab control), indicating a potential for biological scab disease control. In the field, none of the products performed better than PCNB for scab control (Figure 5), although yield from PCNB treatment was the lowest (Figure 6). These results will be further explored and addressed and re-tested during the next growing season. Horseradish had significantly reduced the growth of Streptomyces spp. (all were pathogens to potato) in Petri plates by volatiles (Figure 7), and potato common scab in the greenhouse (Figure 8). Strain 3024 was the most sensitive, and 2794 was least sensitive, but ED50 was all bellow 0.5 g dry plant material per plate. To summarize, pyrosequencing result will provide detailed information for finding beneficial microorganisms and healthy soil microbial community. BAC03 strain and horseradish have potential for controlling potato common scab. Field data will be pursed in the future.   130 Hao 2010 Report to MPIC Table 1. Selected genera identified from pyrosequencing. Pseudomonas Lysobacter Rhodanobacter Streptomyces Bacillus Conducive soil 1.2 1.6 471.8 11.8 54.8 Suppressive soil 22.4 9.6 1205.2 10.4 5.2 Table 2. Effect of chestnut pellicle extract on test pathogens. Pathogen Clavibacter michiganensis subsp. Michiganensis Erwinia carotovora Pseudomonas syringae Streptomyces scabies Streptomyces acidiscabies Streptomyces bottropensis Streptomyces aureofaciens Streptomyces stelliscabiei Streptomyces europaeiscabiei Cladosporium cucumerinum Phytophthora capsici Phytophthora infestans Pythium irregulare Verticillium dahliae EC50 (ug/uL) 21.5 20.5 6.1 12.0 9.2 13.3 5.6 14.4 13.0 16.4 32.6 28.5 18.7 13.4   131 Hao 2010 Report to MPIC H E R 2 1 , M I H E R 2 2 , M I H E R 2 3 , M I H E R 2 4 , M I S . s t e l l i s c a b e i i 3 2 9 , S . S e t l l i s c a b e i i 7 9 1 , S . s t e l l i s c a b e i i 7 9 4 , S . S e t l l i s c a b e i i 3 2 9 3 , Figure 1. Electrophoresis of PCR products on agarose gel (1.2%). Genomic DNAs of the isolates were amplified using BOX-PCR. Isolates HER21 to 24 were from Michigan, and the rest were from New Your (NY), Wisconsin (WI), Massachusetts MA). D N A L a d d e r S A T C C 4 9 1 7 3 . S c a b e s i S . s t e l l i s c a b e i i , P A Figure 2. Venn diagram indicating shared and unique observed bacterial taxa between disease suppressive- and disease conducive- soil. Number of tax based on 10% DNA sequence dissimilarity. D2: disease conducive-soil and DSC: disease suppressive-soil. The number of taxa in groups D2, DSC and shared between groups was 565, 859, and 300 respectively. 26.69% of taxa are shared in groups D2 and DSC and the total taxa among all groups is 1,124. 80   60   40   20   0   0   ! ) % ( x e d n i e s a e s D i Radish! y  =  66.137e-­‐0.04x   R²  =  0.78342   75   50   25   30! 25! 20! 15! 10! 5! 0! ! ) % ( x e d n i e s a e s D i 0! 100   Potato! y = -0.2026x + 25.482! R² = 0.98857! 25! 50! 75! 100! Chestnut tissue in soil (%)! Figure 3. Effect of chestnut tissue incorporated in soil on scab disease (Streptomyces scabies) in potato and radish in the greenhouse.   Chestnut tissue content ratio! 132 Hao 2010 Report to MPIC a   a   a   ab   a   a   dry  leaves   dry  roots   abc   bc   b   b   ab   c     ) g (   t h g i e w h s e r F   0  5  10  15  20  25   fresh  leaves   fresh  roots           1 C A B 2 C A B 3 C A B B N C P T N N -­‐ T N     I             1 C A B 2 C A B 3 C A B B N C P -­‐ n o n d e t a e r t d e t a e r t -­‐ n o n Figure 4. Effect of Bacillus spp. on scab caused by Streptomyces scabies in radish (left panel), and potato (right panel). Controls included PCNB treatment, and non treatment (NT). All pots were infested with S. scabies before soil treatment, except NT-NI. Multiple pair-wise comparisons were performed for leaf and root weight separately, using Fisher’s least significance difference (LSD). Values followed by same letters were not significantly different at α = 0.5. 4   3   2   1   0     ) g (   t h g i e w h s e r F   2   1.5   1   0.5   0   ! x e d n i b a c S 0.6   0.4   0.2   0   a   ab   ab   b   Montcalm! b   c   ! a i l a g e R ! t u n t s e h C ! t e n e T ! C A B ! B N C P ! T N CSS! ! a i l a g e R ! t u n t s e h C ! t e n e T ! C A B ! B N C P ! T N Figure 5. Soil treatment on potato common scab. Yields from different treatments were compared using Fisher’s least significance difference (LSD) method at different at α = 0.5. Values followed by the same letter were not significantly different. b! b! b! a! ab! ab! 75! 60! 45! 30! 15! 0! Figure 6. Effect of soil treatment on potato yield at Montcalm, 2010. Eighteen plants were harvested in each plot. Yields from different treatments were compared using Fisher’s least significance difference (LSD) method at α = 0.5. Values followed by the same letter were not significantly different. l / ! ) t o p b l ( d l e i Y   133 Figure 7. Effective dose of horseradish volatiles for 50% of growth inhibition (ED50) on Streptomyces spp. on Petri plates. A series of doses of dried horseradish were placed in a flipped Petri plate (with lip placed on the bottom and the bottom part on the top), which contained YME medium on the top and culture of Streptomyces spp. Regression was calculated based on the responses against the dosage, and ED50 was calculated using the regression equation. Figure 8. Effect of non-chemical compounds against potato common scab in the greenhouse. Treatments included SS: non-treatment; Regalia (5%); BAC (Bacillus strain BAC03) at 108CFU/cm3; Horseradish @5g/gallon soil; and CK (non-treated). Prior to the treatment, soil was all infested with S. scabies, except CK. Hao 2010 Report to MPIC l ! ) e t a p g ( / 0 5 D E 0.6! 0.5! 0.4! 0.3! 0.2! 0.1! 0! ! e r o c s b a c S 1.5! 1! 0.5! 0! a! ! S S Streptomyces isolates! b! ! a i l a g e R b! ! C A B b! ! K C b! ! i h s d a r e s r o H   134 2010 Research Summary  Loren G. Wernette and George W. Bird  Corky Ring‐spot disease of potato (CRSD) has been detected in two Michigan potato fields, one    in St. Joseph Co. and the other in Saginaw Co.  The infectious agent is the Tobacco Rattle Virus (TRV) that  is vectored by the Stubby‐Root nematode (Paratrichodorus pachydermus).  This virus, which can reside  asymptomatically in most crop and weed species, causes sprang or necrotic brown ringing and arching in  the tissue of the tuber.  It does not display foliar symptoms in field settings leaving the grower unaware  of any problem until the harvest is complete.  The disease is not known to cause any yield loss but can  reduce quality to a point that loads may be rejected from the processor if the symptom expression is  severe enough or if CRSD is compounded with defects of other kinds.  The vector P. pachydermus is a migratory nematode that shows up in low population densities    quite frequently in many sandy soils across the state of MI.  Generally P. pachydermus is ignored, as the  threshold for treatment is significantly higher than what is commonly seen (≈100/100cm3 soil).  It has  the capacity to feed on most if not all rotational crops grown in a potato system including corn and  wheat.  It is generally found closer to the soil surface in the spring of the year when soils are higher in  moisture and lower in temperature.  As the soils dry and warm the nematodes move deeper into the soil  profile and thus out of the range of standard sampling.  In 2009 the CRSD research that began in 2008 was continued.  The location of the 2009 field site    was adjacent to the field site that had been used for the 2008 CRSD research.  In 2008 it had been  planted to field corn, and in 2009 was planted by Walther’s Farms to c.v. FL 1879.  Prior to planting (May  30) specific areas of the field were fumigated with Sectagon 42 (metam sodium) at the highest labeled  rate of 75 gallons/ acre.  Two weeks later Vydate C‐LV (Oxymyl) was applied in furrow.  Throughout the  growing season; starting at tuber initiation, foliar applications of Vydate C‐LVwas applied at two week  intervals for a total of four foliar applications.  The plots were 180 feet long by 36 feet wide and were  designed in a randomized block design with seven treatments being replicated four times (Table 1).    At the end of the growing season the field was desiccated and harvested (Oct. 5) with the help    of Chris Long and Rob Schafer.  Each plot had four ten foot sections harvested which were then placed in  crates and taken to the Clarksville Research Station where they were put in storage at 50°F.  One month  following harvest  grade A yields of each ten foot section were determined for each plot.  Ten tubers  were also randomly selected from each crate, a total of 40 tubers per plot.  These tubers were cut bud  end to stem end, and were visually inspected for the symptom expression of CRSD.  The symptom  expression measurements were done again three more times, at one month intervals to make sure  there was no increase in symptom expression as storage time increased.  Any tubers that showed  symptom expression were taken back to the lab and one of three molecular test were run on them to  determine the presence of the TRV virus in the tuber.  RT‐PCR was used in Dr. Kirk’s lab, Transmission  electron microscopy (TEM) was preformed to observe virus particles present in the tuber tissue, and  tubers were sent to Pest Pros Inc. in Plainfield, WI to have real‐time PCR run on them to determine the  present and quantity of TRV.   135 In the 2009 study our yield ranged from 442 cwt to 488 cwt with no significant differences    between any of our treatments which is what was expected.  The symptom expression that was seen  throughout the storage season ranged from 2.67% to 0%.  The control treatment showed significantly  more symptom expression than treatments that incorporated either a Vydate C‐LV in furrow treatment  or some amount of Vydate C‐LV foliar treatment, or had Sectagon 42 applied in the spring at the highest  ladled rate.  The control was not however, significantly different than the Vydate C‐LV alone in furrow or  alone applied as a foliar application (Figure 1).  When we looked at the percent symptom expression  over time in storage we did not see any increase, which corresponds with work that was done by Dr.  David out in North Dakota.  When TEM was used to look for TRV no virus particles were seen.  When Rt‐ PCR was used positive confirmations were rare.  When symptomatic tubers were sent to Pest Pros Inc.  only 33% of the tubers that were sent, came back positive for TRV and the amount of TRV that was  picked up was at very low levels.  This could describe the lack of TRV that was found in both the TEM  and the RT‐PCR.  Following the calculation of  grade A yield and symptom expression the percent of symptom    expression was removed from the Grade A yield and economics were run using an average potato price  of $10/cwt Vydate C‐LV costing $68/gallon and Sectagon 42 at $4.5/gallon.  We showed that the control  had the lowest economic return at only $4040, while the Vydate C‐LV in furrow + 2 foliar treatments of  Vydate C‐LV had the highest economic return at $4672 (Table 2).  Following our 2009 research, we questioned why so few virus vectors were seen in our sampling    throughout the growing season.   So in the fall of 2010 a vertical distribution study was performed on  both known infested fields in MI.  Field 1 in St. Joseph Co. was split into five sections, 20‐30 soil probes  at three different depths (0‐6 in, 6‐12 in and 12‐18 in) were sampled for each section. Two other fields  were sampled at two depths (0‐6 in. and 6‐12 in.) in an ongoing fumigation study being conducted by Dr.  Bird.   The field in Saginaw Co was split into ten sections and sampled in the same way at the same three  depths.  Samples were taken back to the lab where the nematodes were extracted and the Pratylenchus  penetrans (Root lesion nematode) and Paratrichodorus pachydermus (Stubby‐root nematode) were  identified and counted for each section at each depth.  We found that in the fall of the year the majority of P. pachydermus the primary vector of TRV is    found below 12 inches far outside the range of standard agronomic soil sampling (Table 3).  While the  root lesion nematode, a major component in the Potato‐Early Die complex, population densities were  highest in the top 12 inches of soil (Table 4).  These results will be followed up in the 2010‐11 fumigation  study that is being conducted by Dr. Bird.          136 Table 1 2009 Corky Ring‐Spot Disease Research treatments  Chemical application (rate)    Control    4 foliar applications Vydate C‐LV(2 pts/A)    Vydate C‐LV in furrow (4 pts/A)    Vydate C‐LV in furrow(4pts/A) + 4 foliar applications Vydate C‐LV (2 pts/A)    Vydate C‐LV in furrow (4 pts/A) + 2 foliar applications Vydate C‐LV (2 pts/A)    Sectagon 42 (75 gallons/A)    Sectagon 42 (75 gallons/ Acre) + Vydate C‐LV in furrow (4 pts/A)+4 foliar applications  Vydate C‐LV (2 pts/A)    Treatment #    1    2    3    4    5    6    7        Figure 1 2009 Corky Ring‐Spot Disease Symptom expression for seven treatments    n o i s s e r p x E m o t p m y S %   3 2.5 2 1.5 1 0.5 0 A1 AB AB 1 2 3 B 4 Treatments B 5 B 6 B 7   1 Different letters indicate statistical significant differences (<0.05)  137 Table 2 2009 Economic returns on Corky Ring‐Spot Disease Research after removing percent Symptom  expression  Treatment #  Treatment  Net Return ($)/A 1                     Control  4 foliar applications Vydate C‐LV  Vydate in furrow  Vydate in furrow + 4 foliar applications  Vydate in furrow + 2 foliar applications  Vapam 75 gallons/acre  Vapam+ Vydate in furrow + 4 foliar applications      $4040   $4202   $4266   $4558   $4672   $4543   $4401     1 Numbers figured using a average potato price of $10/cwt, Vydate C‐LV at $68/gallon and Sectagon 42  at $4.5/gallon                          138 Table 3. Absolute and relative population densities of the vertical distribution of Paratrichodorus  pachydermus at three soil depths associated with four potato fields in Michigan.  Mean (range)2 Nematodes/100 cm3  0 (0‐0) c 2.4 (2‐3) b  4.6 (2‐7) a  0 (0‐0) c  0.2 (0‐2) b  1.2 (0‐5) a                  0 (0‐0) b  0.75 (0‐4) a  0 (0‐0)  0 (0‐0)    Location1  Field 1  Field 2  Field 3  Field 4                                  Soil Depth  (cm)      0‐15 cm  15‐30 cm  30‐45 cm      0‐15 cm  15‐30 cm  30‐45 cm      0‐15 cm  15‐30 cm      0‐15 cm  15‐30 cm    Relative  density          0.0  34.3  65.7      0.0  14.3  85.7      0.0  100.0      0.0  0.0    S.E.  ±0.00  ±0.24  ±0.81  ±0.00  ±0.20  ±0.49  ±0.00  ±0.40              ‐  ‐    1 Field 1 in St. Joseph Co. (41.770256N, ‐85.683557W), Field 2 in Saginaw Co. (43.371647N, ‐84.266406W), Field 3 in Tuscola Co.   (43.530707N, ‐83.22839W), and Field 4 in Mecosta Co. (43.514355N,‐85.365533W)  2 Column group means followed by the letters are not statistically different (P=0.05) according to Tukey’s test.                    139 Table 4. Population of Pratylenchus penetrans  in Absolute and relative population densities four  Michigan fields at multiple soil depths.   Mean (range)2  Nematodes/100 cm3  Relative  density  Location1  Field 1  Field 2  Field 3  Field 4                                  Soil Depth  (cm)      0‐15 cm  15‐30 cm  30‐45 cm      0‐15 cm  15‐30 cm  30‐45 cm      0‐15 cm  15‐30 cm      0‐15 cm  15‐30 cm          28.2 (13‐49) a 31.8 (17‐46) a  19.2 (8‐35) a              3.8 (0‐10) a  3.1 (0‐8) ab  0.8 (0‐3) b  20 (0‐40) b  38.5 (12‐88) a  4.6 (0‐13) b  14.3 (4‐37) a  S.E.  P Value        ±6.24  ±4.81  ±4.91  ±1.05  ±0.85  ±0.33  ±2.94  ±5.33  ±0.80  ±2.52                                0.269  0.035  0.006  0.001        35.6  40.2  24.2  49.4  40.3  10.4  34.2  65.8  24.3  75.7              1 Field 1 in St. Joseph Co. (41.770256N, ‐85.683557W), Field 2 in Saginaw Co. (43.371647N, ‐84.266406W), Field 3 in Tuscola Co.   (43.530707N, ‐83.22839W), and Field 4 in Mecosta Co. (43.514355N,‐85.365533W)  2 Column group means followed by the letters are not statistically different (P=0.05) according to Tukey’s test.    140 2009-2010 DR. B. F. (BURT) CARGILL POTATO DEMONSTRATION STORAGE ANNUAL REPORT MICHIGAN POTATO INDUSTRY COMMISSION Chris Long, Coordinator Introduction and Acknowledgements Round white potato production leads the potato market in the state of Michigan. Michigan growers continue to look for promising new, round white varieties that will meet necessary production and processing criteria. There are many variety trials underway in Michigan that are evaluating chipping varieties for yield, solids, disease resistance and chipping quality with the hope of exhibiting to growers and processors the positive attributes of these lines. Extended storage chip quality and storability are areas of extreme importance in round white potato production. Due to the importance of these factors, all new varieties that have the potential to become a commercial chip processor will have storage profiles developed. Being able to examine new varieties for long-term storage and processing ability is a way to keep the Michigan chip industry at the leading edge of the snack food industry. This information can position the industry to make informed decisions about the value of adopting these varieties into commercial production. The Michigan Potato Industry Commission (MPIC) Burt Cargill Potato Demonstration Storage facility currently consists of two structures. The first building, constructed in 1999, provides the Michigan potato industry the opportunity to generate storage and chip quality information on newly identified chip processing clones. This information will help to establish the commercial potential of these new varieties. This demonstration storage facility utilizes six, 550 cwt. bulk bins (Bins 1-6) that have independent ventilation systems. The second structure built in 2008, has three 600 cwt. bulk bins that are independently ventilated. The first of these bulk bins, bin seven, has been converted into box bin storage that holds 36, 10 cwt. box bins to provide storage profiles on early generation potato varieties. The box bin is an entry level point in storage profiling that allows the industry to learn about a varieties’ storability before advancing to the bulk bin level. We would typically have 4-6 years’ worth of agronomic data on a variety before entering box bin testing. In the variety development process, little information has been collected about a varieties’ storability or storage profile prior to being included in the box bin trial. A storage profile consists of bi-weekly sampling of potatoes to obtain; sucrose and glucose levels, chip color and defect values. In addition, each variety is evaluated for weight loss or shrinkage and pressure bruise. With this information, the storage history of a variety can be created, providing the industry with a clearer picture of where a line can or cannot be utilized in the snack food industry. The Michigan potato industry hopes to use these storage profiles to improve in areas such as long-term storage quality, deliverability of product and, ultimately, sustained market share. 141 The two remaining 600 cwt. bulk bins in the second structure are designed to be used to evaluate the post-harvest physiology of the potato. The facility can be used to evaluate storage pathology or sprout inhibitor products. The Michigan industry recognizes the importance of being able to control disease and sprout development in storage and is committed to doing research in these areas. This ninth annual Demonstration Storage Report contains the results of the storage work conducted in the facility during the 2009-2010 storage season. Section I, “2009-2010 New Chip Processing Variety Box Bin Report”, contains the results and highlights from our 10 cwt. Box Bin study. Section II, “2009- 2010 Bulk Bin (500 cwt. Bin) Report”, shows bulk bin results including information from commercial processors regarding these new varieties. The storage facility and the work done within it is directed by the MPIC Storage and Handling Committee and Michigan State University (MSU) faculty. The Chair of the committee is Brian Sackett of Sackett Potatoes. Other members of the committee include: Bruce Sackett, Steve Crooks, Todd Forbush, Chris Long, Troy Sackett, Dennis Iott, Randy Styma, Keith Tinsey, Ben Kudwa and Tim Young. The funding and financial support for this facility, and the research that is conducted within it, is largely derived from the MPIC. The committee occasionally receives support for a given project from private and/or public interests. We wish to acknowledge all the support and investment we receive to operate and conduct storage research. First, we express our gratitude for the partnership we enjoy between the MPIC and Michigan State University. Thank you to the MPIC Storage & Handling Committee for their investment of time, guiding the decisions and direction of the facility. Brian Sackett, Sackett Potatoes; Larry and Troy Sackett, Sackett Ranch, Inc.; Steve, Norm and John Crooks, Crooks Farms, Inc.; Tim and Todd Young, Sandyland Farms and Kim and Kyle Lennard, Lennard Ag Co.; these are the growers that provided the material to fill the bulk bins this year and without their willingness to be involved, we could not have accomplished our objectives. Equal in importance are the processors who invested in this research. They are; Gene Herr, Herr Foods Inc., Nottingham, PA; Mitch Keeny of UTZ Quality Foods, Inc., Hanover, PA; Al Lee and Paul Geiser of Better Made Snack Foods, Detroit , MI. It has been a great pleasure to work with all of you. Special thanks to Butch and William Riley (Gun Valley Ag. & Industrial Services, Inc.) for their annual investment in the sprout treatment of the storage facility. We would also like to acknowledge a long list of additional contributors who invested much time to help foster a quality storage program: Dr. Dick Chase (MSU Professor Emeritus), Dr. Dave Douches and the MSU potato breeding program, Todd Forbush (Techmark, Inc), Larry Jensen (Chief Wabasis Potato Growers), and Tim Wilkes (Potato Services of Michigan). All played a role in making this facility useful to the Michigan potato industry. 142 Overview of the production season * The overall 6-month average maximum temperature during the 2009 growing season was two degrees lower than the 6-month average maximum temperature for the 2008 season and was one degree lower than the 15-year average. There were three recorded temperature readings of 90 °F or above in 2009. This high temperature event was recorded during a period of time from June 23rd to June 25th, prior to tuber bulking. There were no recorded daytime temperatures above 90 °F or night time temperatures above 70 °F in the month of August. There were two days in May that the air temperature was below 32 °F. This occurred on May 11th and 18th. The average maximum temperatures for July, and August 2009 were six and three degrees below the 15-year average, respectively. In October 2009, there were 15 days with measureable rainfall and eight daytime highs below 50 °F. Six of these eight days fell on days with no recorded rainfall, leaving only 10 days in October that had no rain and temperatures above 50 °F. Rainfall for April through September was 16.82 inches, which was 2.4 inches below the 15-year average. Rainfall recorded during the month of August was the highest recorded for that month since the year 2002. In October 2009, 3.79 inches of rain were recorded. Overall, the 2009 growing season resulted in above average specific gravity with average overall yields. The early part of the season was cool and dry. The harvest season was generally wet and cool. * Weather data collected at the MSU, Montcalm Research Farm, Entrican, MI. 143 I. 2009-2010 New Chip Processing Variety Box Bin Report (Chris Long and Brian Sackett) Introduction The purpose of this project is to evaluate new chip processing varieties from national and private breeding programs for their ability to process after being subjected to storage conditions. A variety’s response to pile temperature, as reflected in sucrose and glucose levels, is evaluated. Weight loss and pressure bruise susceptibility of each variety is also evaluated. Bin 7 contained 36, 10 cwt. boxes. Thirty-six boxes were placed in six stacks of six. The boxes were designed for air to travel in from a header or plenum wall through the forklift holes of each box, up through the potatoes within it and onto the next box above until the air reaches the top and is drawn off the top of the chamber, reconditioned and forced back through the header wall plenums and up through the boxes again. Each box contains a sample door facing the center aisle from which tubers can be removed to conduct bi-weekly quality evaluations. Procedure Sixteen new varieties were evaluated and compared to the check variety Snowden. The 16 varieties were chosen by the MPIC Storage and Handling Committee. Once the varieties were chosen, 1 cwt. of each variety was planted on May 12th at the MSU, Montcalm Research Farm, Entrican, MI. The varieties were planted at a 10” spacing with the Snowden check variety being planted at 12”. All varieties received a rate of fertilizer recommended to achieve a 350 to 400 cwt/A yield (270 lb. N/A). The varieties were vine killed after 114 days and allowed to set skins for 20 days before harvest on September 23, 2009; 134 days after planting. Variety maturity is not taken into account in the harvest timing due to storage and handling restrictions. Approximately ten cwt. of each variety was placed in each box bin, labeled and stacked in Bin 7. The average storage temperature for all the box bins (Bulk Bin 7) was 55 ºF for the 2009-2010 season. At harvest, nine, 20 lb. samples from each variety were collected for weight loss and pressure bruise evaluation. Some additional tuber samples were taken and shipped to regional chip plants for evaluation throughout the storage season. A description of the varieties tested, their pedigree and scab ratings are listed in Table 1. Yield, size distribution, chip quality, and specific gravity were recorded at harvest (Table 2). All 17 varieties were graded to remove all “B” size tubers and pick-outs and entered the storage in good physical condition. The storage season began September 23, 2009 and ended June 1, 2010. Bin 7 was gassed with CIPC on November 2nd 2009 and again on December 7th 2009. Variety evaluation began October 7th 2009 followed by a bi-weekly sampling schedule until June. Thirty tubers were removed from each box every 144 two weeks and sent to Techmark, Inc. for sucrose, glucose, chip color and defect evaluation. Nine pressure bruise sample bags were taken for each variety, weighed and placed in one of the bulk bins at the storage facility. Three bags were placed at each of 3’, 6’ and 9’ from the pile floor. When that bin was unloaded, the sample bags were weighed and percent weight loss was calculated. A 25 tuber sample was taken from each of the nine bags and was evaluated for the presence or absence of pressure bruise. The number of tubers and severity of bruise were recorded. All pressure bruises were evaluated for discoloration. This report is not intended to be an archive of all the data that was generated for the box bin trial, but a summary of the data from the most promising lines. The purpose of this report is to present a summary of information from 2-4 lines from this trial that will be moved along the commercialization process. If more detailed information is desired, please contact Chris Long at Michigan State University in the Crop and Soil Sciences Department for assistance (517) 355-0271 ext. 1193. 145 Table 1. 2009 MPIC Demonstration Box Bin Variety Descriptions 2009 Scab Rating* Characteristics High yield, late maturity, late season storage check variety, reconditions well in storage, medium to high specific gravity High U.S. No. 1 yield, scaly buff skin, high High yielding, scaly buff chipper; smaller specific gravity tuber size Medium-high yield potential, small tuber size, minimal grade defects, medium-early maturity, high specific gravity, some ability to recondition out of 40º F High yield potential, small size profile, minimal grade defects, early maturity, medium-high specific gravity, some ability to recondition out of 40º F Medium-high yield potential, minimal grade defects, medium-early maturity, medium- high specific gravity, ability to recondition out of 40º F Average yield, mid-season maturity, blocky flat tuber type, shallow eyes, medium specific gravity Medium-high yield, cold chipper from 45º F, uniform A-size tubers, attractive appearance, good internal quality, long term storage potential, medium specific gravity Average yield, early to mid-season maturity, uniform tuber type, medium specific gravity, scab resistant Above average yield, scab susceptible, late blight susceptible, medium-high specific gravity, long storage potential Flattened blocky round type, some early bulking, scab resistant Bright chips, low incidence of defects, medium specific gravity Round tuber type, late maturity, scab and late blight resistant, high specific gravity, strong vine and roots High yield, large round tubers, good internal qualities Average yield, round tuber type with netted skin, low sugars, PVY resistant, moderate late blight resistance Entry Snowden (W855) A00188-3C A01143-3C CO00188-4W Pedigree B5141-6 X Wischip A91790-13 X Dakota Pearl COA95070-8 X Chipeta A90490-1W X BC0894-2W CO00197-3W A91790-13W X NDTX4930-5W CO00270-7W BC0894-2W X A91790-13W MSH228-6 MSC127-3 X OP MSJ126-9Y Penta X OP MSL007-B MSL292-A MSN170-A MSA105-1 X MSG227-2 Snowden X MSH098-2 MSI055-5 X MSG227-2 MSP459-5 Marcy X NY121 MSQ070-1 MSQ279-1 MSK061-4 X Missaukee Boulder X Pike MSR061-1 W1201 X NY121 2.3 1.3 1.3 2.0 3.1 2.8 1.3 1.3 1.0 2.3 1.3 1.8 1.3 1.4 1.1 *Scab rating based on 0-5 scale; 0 = most resistant and 5 = most susceptible 146 Entry NY 139 (Y28-9) W5015-12 Pedigree NY120 X NY115 Brodick X W1355-1 2009 Scab Rating* 1.5 - *Scab rating based on 0-5 scale; 0 = most resistant and 5 = most susceptible Characteristics High yield, mid-late season maturity, medium specific gravity Relative high tuber set and yield, medium- late vine maturity, uniform size tubers, tubers tend toward flat shape, very flat in some environments 147 Table 2. 2009 Michigan Potato Industry Commission Box Bin Processing Potato Variety Trial LINE MSH228-6 NY139 MSQ279-1 A00188-3C CO00197-3W A01143-3C MSN170-A MSQ070-1 MSL292-A Snowden CO00270-7W W5015-12 MSL007-B MSP459-5 MSR061-1 MSJ126-9Y CO00188-4W CWT/A US#1 TOTAL 297 315 263 238 228 226 225 219 214 207 196 183 178 176 170 155 118 92 296 301 302 297 297 242 274 257 234 221 247 231 219 219 152 181 252 MEAN 199 2009 MPIC Box Bin Processing Potato Variety Trial Montcalm Research Farm, Montcalm County, MI Harvest 23-Sep-09 134 Days DD, Base 406 2703 PERCENT OF TOTAL1 OV Bs 6 5 As 89 CHIP TUBER QUALITY2 PO 0 SP GR SCORE3 1.079 1.0 HH 1 VD 2 IBS 0 BC 0 TOTAL CUT 10 11 20 24 20 21 8 23 19 16 16 26 24 21 29 16 49 89 67 74 76 74 79 74 79 84 81 69 76 76 68 78 51 0 12 2 0 2 12 3 2 0 2 3 0 2 3 0 0 0 1 0 4 3 1 0 0 0 1 2 0 1 0 6 0 1.083 1.084 1.082 1.080 1.078 1.084 1.090 1.081 1.085 1.079 1.086 1.080 1.080 1.082 1.077 1.083 1.082 1.0 2.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.5 1.0 0 1 2 0 0 0 2 1 1 0 0 0 1 2 0 0 2 0 1 3 0 0 0 1 2 2 3 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 0 0 0 0 0 0 0 0 0 0 0 0 0 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 US#1 94 89 79 76 76 76 91 77 81 84 83 72 76 78 71 78 51 78 2.0 3.0 2.0 2.5 2.0 2.0 1.5 2.0 2.5 2.0 2.0 2.0 1.5 1.5 2.0 1.0 2.5 4.5 3.5 4.5 3.5 3.5 4.5 3.5 4.5 3.5 3.5 2.5 4.5 3.5 2.5 3.5 2.5 1.5 VINE VIGOR4 MATURITY5 VINE COMMENTS CHIP COMMENTS flat oval, tr surface scab 1 SED tr surface scab gc in pickouts, tr surface scab, sheep nose many chips with discoloration gr and misshapen in pickouts misshapen in pickouts misshapen in pickouts, nice size and profile round uniform type 4 SED uniform type pitted scab russeted skin nice uniform type sl sheep nose misshapen in pickouts, small size 3 SED small bright appearance tr = trace, sl = slight, N/A = not applicable SED = stem end defect, gc = growth crack Planted: Vines Killed: Days from Planting to Vine Kill: Seed Spacing: No Fumigation 12-May-09 3-Sep-09 114 10" 6MAWN STATION: Entrican Planting to Vine Kil 1SIZE Bs: < 1 7/8" 2TUBER QUALITY (number of tubers per total cut) HH: Hollow Heart 3CHIP COLOR SCORE - Snack Food Association (Out of the field) As: 1 7/8" - 3.25" VD: Vascular Discoloration OV: > 3.25" IBS: Internal Brown Spot PO: Pickouts BC: Brown Center Ratings: 1 - 5 1: Excellent 5: Poor 4VINE VIGOR RATING Date Taken: 15-Jun-09 Ratings: 1 - 5 1: Slow Emergence 5: Early Emergence (vigorous vine, some flowering) 5VINE MATURITY RATING Date Taken: 14-Aug-09 Ratings: 1 - 5 1: Early (vines completely dead) 5: Late (vigorous vine, some flowering) 148 ts: 2009-2 2010 New w Chip Pr rocessing g Box Bin n Report Result MSH22 28-6 6 is a Michiga d common sc g variety. Th ight tubers th h a strong ne as medium an yielding varie ble 2). The va rity and a sma ould be plant cing and man day maturity. -like storage eason, MSH2 0) and a gluco se levels beg s period. Tub weight loss in tion under the ial testing in h e. The storab vantage. an State Univ cab resistant, his variety has hat are round etted skin. Th nd was the hig ety in the 2009 ariety appeare all set sugges ted at an eigh naged for a 13 This variety h profile, exhibi 228-6 was pla ose value of 0 an to increas ber weight los the sample c e bruises. Ov hopes of repla bility of MSH2 versity (MSU) chip s a tuber set to oval in he specific ghest 9 Box Bin ed to have a sting that this ht inch in-row 30 to 140 has a iting the abilit aced into stora 0.005 mg/g. T e. A chip pic ss data that w collected with verall, this var acing some S 228-6 is simila MSH228- developed processin of six to e shape wit gravity wa recorded Trial (Tab late matur variety sh seed spac growing d Snowden- storage se mg/g (X10 the sucros during this average w discolorat commerci resistance its big adv MSL29 This MSU “A” sized gravity. T clone yield tuber type round. Th performed colder gro quality of y to store we age on Septe These values ture is include was collected d 2.2 percent o iety performe Snowden acre ar to Snowden ll into March ember 23rd 20 s decreased q ed from Marc during the sto of the tubers e ed well enoug eage with a va n but the com in most years 009 having a s quickly until e ch 15th 2010 to orage season exhibiting pre h to warrant f ariety that has mmon scab to s. During the sucrose value arly March 20 o show the ch n showed a 1. essure bruisin further large s s common sc lerance of this 2009-2010 e of 0.634 010 when hip quality .86 percent ng and scale cab s variety is 2-A U variety exhib tubers with a The 2009 Box ding 207 cwt. e and size of M he overall Box d below expec owing season MSL292-A ha bited an avera good proces x Bin Trial reco ./A US#1 (Tab MSL292-A is x Bin Trial in 2 ctations, poss . The long te as been exce age yield of sing specific orded this ble 2). The uniform and 2009 sibly due to a erm chip ellent. The 149 vine matu variety. O 0.005 mg/ and 0.001 From late recorded in the tube 2.25 with only nega yield pote chip proce MSQ27 This MSU mid-seaso common s uniform ro common s specific g vine type In the 200 from the t US#1 (Ta appeared variety is these tube sucrose le remained pictured a recorded discolorat needs to b tolerance season ch 79-1 wn for good U developed c on storage ch scab toleranc ound type, a m scab toleranc ravity ranges has tended to 09 Box Bin Tr op in yield. It able 2). The in to be good a medium-late. ers were plac evel did come low into early above on Mar was moderat tion under the be monitored is good. This hip quality and clone is know hip quality, as ce. MSQ279- medium nette ce is similar to from 1.075 to o be strong a ial, MSQ279- t produced 23 nternal tuber and the vine m On Septemb ced into storag e down steadi y March. Dur rch 1st 2010 w e at 3.58 perc e skin. This n closely as we s variety, alth d common sc well as -1 has a large e ed skin. The o Pike. The o 1.084. The nd upright. -1 was third 38 cwt./A quality maturity of the e ber 23rd 2009 9 ge. The sucro ose level appe February 2010 ily into early F rch 2010, the ring early Mar with a 0.604 su ucrose rating 2 percent of t cent, with 14. uite high and umber was q e move forwa ard. Overall, t ng a few reas ough exhibitin cab tolerance thus warrant urity for MSL2 On Septembe /g glucose va 1, respectively March 2010 for this variet ers which can only 3.1 perc ative aspect to ential and exce ess in early J 92-A is mediu r 23rd 2009, th alue. Sucrose y. At this poin until June 1st y on May 24th n be observed cent of the tub o this clone is ellent long ter une most sea um-late. A te his variety wa e and glucose nt in storage, 2010, the glu h 2010 were 6 d in the pictur bers evaluated s the lack of st rm storability asons. en inch in-row as put into sto e levels came the sucrose v ucose level re 6.9 percent, re re above. The d expressing trong commo for chip proce w seed spacin orage with a 0 down to thei values began emained at or esulting large e percent we bruise with d on scab tolera essing. This g would be re 0.819 mg/g (X r lowest point n to rise to 0.7 r below 0.005 ely from free i ight loss reco iscoloration u ance. Overall variety has th ecommended X10) sucrose ts in mid-Mar 785 in early Ju 5 mg/g. Total nternal gluco orded for this v under the surf , this variety h he potential to d for this rating and a ch at 0.488 une 2009. defects se present variety was face. The has great o store and eared to be e 0. The gluco sucrose ratin and 0.002 gl the tubers ex d the pressure this variety yi sons for conc ting further tes elevated at 1.2 ose and sugar ng began to in ucose value. xhibiting press e bruise susce elded well an ern, has show sting. 208 mg/g (X1 r related defe ncrease. MS The percent sure bruise wi eptibility of th nd the commo wn good yield 0). The cts Q279-1 is t weight loss ith is line on scab d, mid- 150 nell University ghtly elongate reat yield pote d some mode . In the 2009 bove the trial able 2). NY13 scab toleranc an the check urity for NY139 w seed spaci nded for this NY139 was /g glucose va defects bega ted defects. T rcent of the tu ial potential. y developed c ed and pear s ential, excelle erate commo Box Bin Tria average at 26 39 expresses ce and longer variety Snow 9 is medium-l ng would be variety becau placed into st alue. The suc an to appear. The tuber per ubers having b Its yield and c -12 lone can shaped type, ent chip n scab l, this variety 63 cwt./A better term chip den. The late. A ten use it can torage on Sep crose and gluc The picture a rcent weight l bruise and dis chip quality p NY139 This Corn have a sli but has gr quality an tolerance. yielded ab US#1 (Ta common s quality tha vine matu inch in-row recomme oversize. 0.006 mg/ April chip color relat with 4 per commerci W5015- This Unive has a nice good chip variety yie cwt./A US well unde of the 200 exhibited displayed common s variety Sn 12 is med spacing w with a 1.2 at their low to be quite defects. T ptember 23rd cose levels w above shows oss was the l scoloration un provide the ind 2009 with a 1 were at their lo NY139 in mi lowest of thes nder the skin. dustry with so 1.322 mg/g (X owest in early d-April prior t se four lines r . Overall, this ome potential X10) sucrose y January and to an increase reported at 1. s variety has opportunities rating and a d by mid- e in chip 84 percent great s. ersity of Wisc e uniform type p quality. In th elded below th S#1 (Table 2). r the much co 09 growing se much higher in 2009. W5 scab suscept nowden. The dium-late. A 1 would be reco 02 mg/g (X10 west in late D e good. The The tuber per consin develo e, great yield he 2009 Box he trial averag . This variety ooler growing eason. This v yield potentia 5015-12 has s ibility much li e vine maturit 10 inch in-row mmended for 0) sucrose rat December 200 picture above rcent weight lo oped clone potential and d Bin Trial, this ge at 178 y did not yield conditions variety has al than it some ke the check y for W5015- w seed r this variety. ting and a 0.0 09 and by late e shows W50 oss was repo W5015-12 w 016 mg/g gluc e February, ch 015-12 in early orted at 2.66 p was placed int cose value. T hip defects cl y March, prio percent with 6 to storage on The sucrose a leaned-up an r to an increa 6.2 percent of September 2 and glucose le d chip quality ase in chip co f the tubers h 23rd 2009 evels were y appeared lor related aving bruise 151 and discoloration under the skin. Overall, this variety has good commercial potential. Its yield and chip quality provide the industry with some potential opportunities, but caution must be taken with the lines common scab susceptibility. 152 II. 2009 - 2010 Bulk Bin (500 cwt. Bin) Report (Brian Sackett and Chris Long) Introduction The goal of the MPIC Storage and Handling Committee for the 2009-2010 bulk bin storage season was to develop storage profiles on six promising advanced seedlings and evaluate the effectiveness of Ethylene as a sprout inhibitor, for chip processing potatoes, on the Snowden variety. The first variety tested for storage profiling was Kalkaska, a clone from the potato breeding program at Michigan State University (MSU). This clone has a strong yield potential, early die tolerance and good common scab resistance. Kalkaska was also tested in a bulk bin in the 2008-2009 storage season. The second variety, MSH228-6, is an MSU developed clone that has good common scab tolerance, an oval to oblong type and a storage profile similar to Snowden. MSJ126-9Y, the third variety of interest, is an MSU developed clone with good agronomic quality, common scab resistance and yellow flesh. MSJ147-1 was the fourth MSU line tested in the bulk bins in 2009-2010. The variety is uniform in size, a moderate yielding line, with very good late season storage quality for chip processing. The fifth variety tested in the bulk bin storage was CO95051-7W. This University of Colorado developed clone has some common scab tolerance and good long term chip quality from cold storage. Yield potential is moderate with uniform round tuber type. Bulk bin number 6 contained a new promising russet line from Aberdeen, ID. The name of this variety is Classic Russet (A95109-1). Classic Russet has a uniform blocky type, nice uniform russeted skin and good yield potential. For each of the varieties listed above a brief description of agronomic and storage performance is provided. In addition, a short description of pressure bruise susceptibility, chip color and color defects, sugar accumulation and overall chip quality are given. With this information, a clearer perspective can be obtained regarding the viability of these varieties in commercial production. The goal of the Ethylene Sprout Inhibitor Study was to determine the commercial viability of ethylene gas as a sprout inhibitor in chip processing potatoes and to evaluate the feasibility of replacing CIPC as the industry standard sprout inhibitor. Of particular interest in this study is the ability of ethylene gas to control sprouts adequately while maintaining tuber quality, but most importantly, to see if the ethylene gas would have a negative effect on tuber sugar quality. Sucrose and glucose was evaluated bi-weekly throughout the study and a sprout evaluation was performed at the time of bin unloading to establish the differences in sprout control between the two sprout inhibitor products. 153 Procedure Each bin was filled under contract with potato producers in the state of Michigan. MPIC paid field contract price for the potatoes to be delivered to the demonstration storage. Pressure bruise samples were taken and designated bulk bins were filled. The varieties and their storage management strategies were established by the MPIC Storage and Handling Committee. For each bulk bin filled, a corresponding box bin containing 10 cwt. was filled and placed into Bin 7. Bin 7 was held at a warmer temperature, in most cases, than the corresponding bulk bin of the same variety. Sugar sampling for the box bin was carried out longer into the storage season, in general, than the bulk bin. This allowed the committee to see if the warmer storage temperature in the box bin would reduce storage life and provided information as to how the bulk bin might physiologically age. In the 2009-2010 storage season; Bin 1 was filled with Kalkaska; Bin 2 was filled with MSH228-6; Bin 3 was filled with MSJ126-9Y; Bin 4 was filled with MSJ147-1; Bin 5 with CO95051-7W and Bin 6 was filled with Classic Russet (A95109-1). The Snowden’s in Bin 8 were treated with the industry standard CIPC sprout treatment while Bin 9 was exposed to ethylene gas under controlled conditions. Kalkaska was grown by Sackett Potatoes and was loaded into Bin 1 on September 18, 2009. It was planted April 18, 2009, and vine killed on August 19, 2009 (124 DAP, GDD40 2660). The variety was harvested September 18, 2009; 154 days after planting. The pulp temperature for Kalkaska at bin loading was 68.0 ºF. A blackspot bruise sample was taken on this variety at the time of bin loading. The results indicated that the tubers were 87% bruise free. MSH228-6 was grown by Lennard Ag. Co. and was loaded into Bin 2 on September 28, 2009. It was planted May 22, 2009, vine killed September 15, 2009 (117 DAP, GDD40 2832) and harvested September 27, 2009; 129 days after planting. MSH228-6 pulp temperature at bin loading was 56.0 ºF. A blackspot bruise sample was taken on this variety at the time of bin loading and indicated that the tubers were 68% bruise free. MSJ126-9Y was grown by Thorlund Brothers and was loaded into Bin 3 on October 21, 2009. It was planted May 23, 2009, and vine killed on September 18, 2009 (119 DAP, GDD40 2883). The variety was harvested October 21, 2009; 152 days after planting. The pulp temperature for MSJ126-9Y at bin loading was 63.0 ºF. A blackspot bruise sample was taken on this variety at the time of bin loading. The results indicated that the tubers were 81% bruise free. MSJ147-1, in Bin 4, was grown by Sandyland Farms and was loaded into storage on October 20, 2009 with a pulp temperature of 50.0 ºF. It was planted May 30, 2009, vine killed September 16, 2009 (110 DAP, GDD40 154 2714) and harvested October 20, 2009; 144 days after planting. A blackspot bruise sample was taken on this variety at the time of bin loading and indicated that the tubers where 75% bruise free. CO95051-7W was grown by Sackett Ranch and was loaded into Bin 5 on October 22, 2009. It was planted May 20, 2009, vine killed September 4, 2009 (108 DAP, GDD40 2618) and harvested October 22, 2009; 156 days after planting. The pulp temperature of CO95051-7W at bin loading was 54.0 ºF. A blackspot bruise sample was taken on this variety at the time of bin loading and indicated that the tubers were 78% bruise free. Classic Russet was grown by Sandyland Farms and was loaded into Bin 6 on October 21, 2009. It was planted May 18, 2009, and vine killed on September 2, 2009 (108 DAP, GDD40 2608). The variety was harvested October 21, 2009; 157 days after planting. The pulp temperature for Classic Russet at bin loading was 54.0 ºF. A blackspot bruise sample was taken on this variety at the time of bin loading. The results indicated that the tubers were 67% bruise free. The potatoes placed in Bins 8 and 9 were grown by Johnson Farms, Howard City, MI. Bin 8, Snowden, (Standard CIPC Sprout Treatment) was planted May 20, 2009 and vine killed on September 12, 2009 (116 DAP, GDD40 2822). Harvest took place on October 8, 2009; 142 days after planting. The potatoes were loaded into the bin on October 8, 2009 with a pulp temperature of 54.2 ºF. A blackspot bruise sample was taken on this variety at the time of bin loading and indicated that the tubers where 70% bruise free. The potatoes in Bin 9, Snowden (Ethylene Treated), were identical to the potatoes in Bin 8, thus planting, vine kill, harvest and bin loading dates are identical. A blackspot bruise sample was taken on these Snowdens as they went into Bin 9 and indicated that the tubers were 73% bruise free. The pulp temperature, at filling, remained the same for both Bins 8 and 9 at 54.2 ºF. Bulk Bin 8 was the control bin for the ethylene versus CIPC study. The Snowden potatoes in this bin were managed in a manner consistent with commercial grower storage practices. Bin 9 was the treatment bin. The ethylene concentration in this bin was regulated by an “Ethylene Management Unit” (EMU) developed by the BioFresh Co., United Kingdom. The EMU measured baseline ethylene levels of the inlet air, as well as, the ethylene concentration in the return air of the treatment bin. The EMU had a 200 liter cylinder of commercial grade ethylene gas connected to it. The EMU regulated the injection of this gas into the supply air of the storage to maintain an ethylene set point concentration measured in parts per million (ppm). The tubers were loaded into both Bins 8 and 9 the same day (October 8, 2009) and allowed to wound heal at 54.0 ºF for two weeks. The relative humidity was maintained at 98 percent in both bins. The ethylene injection began on October 20, 2009 and was maintained at 0.1 ppm continually for 7 days (7 Days After First Treatment (DAFT)). At the conclusion of this time period the concentration of ethylene was increased to 0.3 for 7 days (14 DAFT). The ethylene concentration was increased every 7 days from October 20, 2009 until November 24, 2009. This time period represents 5 increases in ethylene concentration. The ethylene concentration in ppm was increased based on the following ranges; 0.1, 0.3, 0.6, 1.0 and 2.0 ppm. Bin 9 remained at each of these ethylene levels for 7 days. On November 24, 2009, the ethylene concentration was increased again to 4.0 ppm and remained at this level for 14 days (49 DAFT). On December 8, 2009, the ethylene level was increased to 8.0 ppm and 155 remained at this level until December 22, 2009 (63 DAFT). Finally, on the 63rd day after the first treatment, the ethylene level was increased for the last time to 10.0 ppm and remained there for the duration of the study. Sucrose and glucose values were evaluated and compared across treatments for both Bins 8 and 9 throughout the sprout inhibitor study. A comparison of sprout suppression was made between treatments by evaluating 3 replicates of 10 tubers from five locations in the potato bulk pile for each treatment. These locations were identified as the following; the sample door, 3 feet above the pile floor, 6-8 feet above the pile floor, 12-14 feet above the pile floor and the top of the pile. At bin loading, three, 25 pound tuber samples were placed in the pile, for sprout evaluation, at each of these locations. At the time of sprout evaluation on January 18, 2010, each of the 10 tuber replicate samples were weighed (150 tubers total per treatment), the number of eyes present were recorded, the number of eyes that were sprouted and 2-5 mm in length were recorded, the number of eyes sprouted greater than 5mm were recorded and the length of the longest sprout was recorded. The sprouts that were recorded as 2 mm and greater in length were removed by hand and the 10 tuber samples were weighed again. The mean was established for; the mass of sprouts, the number of eyes, the number of eyes sprouting 2-5 mm, the number of eyes sprouting greater than 5 mm and the length of the longest sprout in mm. The means of the two treatments were compared to establish effectiveness of sprout control for the two products. Bins 1,2 and 8 were gassed with CIPC on November 2, 2009. On November 25, 2009 Bins 3, 4, 5 and 6 were gassed with CIPC. Bin monitoring began the day the tubers were placed into storage and were evaluated on a two week sampling schedule thereafter. Forty tubers were removed from the sample door in each bin every two weeks and sent to Techmark, Inc. for sucrose, glucose, chip color and defect evaluation. The sample door is located in the center back side of each storage bin and is an access door that allows samples to be taken from the pile three feet above the bottom of the pile. Pressure bruise evaluation began by collecting nine 20 to 25 lb. tuber samples as each bin was being filled. Three samples were placed at each of three different levels within the bulk bin pile at 3, 6, and 9 feet from the storage floor. The pressure bruise samples were evaluated 3 to 5 days after the bin was unloaded. A set of 25 tubers were randomly selected from each bag and visually inspected for pressure bruise. Each bruise was evaluated for discoloration by removing the tuber skin with a knife. A visual rating was given to the bruise for the presence or absence of flesh color (blackening of flesh). Percent weight loss in each tuber sample was calculated as it was removed from the storage. Objective The Storage and Handling committee’s objective in testing the varieties in Bins 1-6 was to determine what the optimal storage temperature was for each variety, while maintaining acceptable storage and chip quality. Also of interest was the level of pressure bruise damage that may be incurred by each variety at a given storage temperature. The goal for the Kalkaska variety was to evaluate longevity at a given storage temperature while maintaining chip quality. Based on blackspot bruise numbers, sugar accumulation and stem end defect, this 156 variety was left warm and slated for a November, December shipping window. MSH228-6 was evaluated for duration of storability. As the chip quality improved in this variety, the pile would be cooled to extend storage life in hopes of reaching a March to April shipping window. Bin 3, MSJ126-9Y, was tested to evaluate the storability of this line. The variety appeared to have vascular and stem end related defects. Sugar accumulation was watched closely around the defect areas before cooling the potatoes to a longer-term storage profile temperature. MSJ147-1 in Bin 4 has long term storage potential into May and June. The sugar and chip quality was good early and the variety was slated for long-term storage. The CO95051-7W, much like the MSJ147-1, has excellent long-term chip quality. The variety was slated for long-term storage quality testing and storage. The Classic Russet in Bin 6 was evaluated for tuber quality and storability for the freshpack market. Resistance to weight loss and Silver Scurf tolerance are important qualities to evaluate throughout the storage season. The goal of the Ethylene Sprout Inhibitor Study in Bins 8 and 9 was to determine the commercial viability of ethylene gas as a sprout inhibitor in chip processing potatoes and to evaluate the feasibility of replacing CIPC as the industry standard sprout inhibitor. Of particular interest in this study is the ability of ethylene gas to control sprouts adequately while maintaining tuber quality, but most importantly, to see if the ethylene gas would have a negative effect on tuber sugar quality. 157 in 1, Kalka aska is a common hip processin State Univers much like tha o its shape an farm variety tr A US#1. It ha rom 2006-200 he specific gra between at 1 as been obser tolerance. scab resista nt, round g variety from m the sity (MSU). T This at of Snowden n in nd skin type. In the rials this line y yielded ar s a three yea 08 of 337 cwt t/A ariety avity of this va .078 – 1.085 . The rved to have g good Bulk Bi Kalkaska shaped ch Michigan variety is regards to 2008 on-f 400 cwt/A average f US#1. Th averages variety ha Early Die For the 20 Mecosta c found to b SFA chip acceptabl varied fro similar ex were stem 58.0 ºF, it and we w remove th Decembe The suga Committe market loa were exce discolorat Kalkaska tolerance, Kalkaska common s 009-2010 stor county. The t be 87 percent rage season, tuber tempera t black spot b this variety w ature upon ar ruise free. was grown by rrival at the st Sackett Pota torage was 68 atoes Mecosta 8.0 ºF. The v a, MI, which i variety was tes s located in sted and color and col e, but glucos m 0.003 to 0. periences in m end defects t was evident ould have to he free sugar. er, we were un r related colo ee to cut losse ad of chip pro ellent at 3.44 tion under the or related def e values were 009. This glu past storage s (SED), see p that this bin o maintain the . At this warm nable to caus r associated w es in this stora ocessing pota percent and o e skin. fects were ac e elevated an ucose variabi seasons with picture in the of potatoes co pile temperat m bin pile tem e enough pos with these de age bin and th atoes and that only 0.4 perce cceptable Oct nd somewhat lity is a conce Kalkaska. M upper right co ontained a sig ture at this lev mperature, ove sitive change efects was not he variety wa t ended our e ent of the tub tober through variable durin ern to overall Most of the int orner of this p gnificant amo vel to encoura er an extende to the amoun t burning off. as shipped on evaluations in ers that expre December. ng this storag chip quality. ternal defects page. After 2 ount of stem e age tuber res ed period from nt of chip defe That prompt n December 2 Bin 1. Tuber essed pressu Sucrose leve els were ge period. Glu ucose levels These result s reflect s recorded in 2009-2010 2 months in th he storage at end vascular d discoloration piration in ord der to m October thro ough ects that were e present. ted the Storag ge 21, 2009, as a an open r weight loss numbers ure bruise had d has exhibited , but the chip was flushed o scab resistan d great agrono quality has b out of the see ce, Early Die omic quality, een too varia ed increase sy tolerance an high yield pot able for comm ystem in the S d yield in the tential, comm mercialization Spring of 201 MSU breedin mon scab resis stance, Early to occur. Any y available se 0. Kalkaska is now a sou ng program. Die eed of rce of 158 in 2, MSH 228-6 6 is a commo oval shaped c om MSU. Thi owden in reg season stora ety trials this l has a three y 9 growing sea he specific gra between at 1 tant, on scab resist ng chip processin much like s variety is m ip quality ards to its ch 009 on- ge. In the 20 07 cwt/A ine yielded 40 ear average, from the 8 cwt/A asons, of 348 avity of this va ariety .078 – 1.085 . Snack Foods B Better Made S M MSH228-6 1 1.083 SG 7 7.7 % Total D 3 3.24.10 Defects Inc. 3. 7 % Color De efects 2.6 6 % Internal D Defects Bulk Bi MSH228- round to o variety fro that of Sn from mid- farm varie US#1. It 2007-200 US#1. Th averages For the 20 variety wa Samaria, The variet SFA chip early Dec temperatu to 0.712 a temperatu appears t It is uncle cooling ra ability to m 0.542 and the storag Thought w can be ev percent w Overall, th the upper lateness, appears to this variet the comm 009-2010 stor as grown by L MI, which is l ty was tested rage season, Lennard Ag. C ocated in Mo and found to this Co. onroe county. o be 68 perce 92.3 % Acceptable 1.4 % External D Defects The tuber te nt black spot pon arrival at emperature up bruise free. the storage w was 56.0 ºF. nd glucose in color and col ember were 0 ure was furthe and 0.003, res ure was raised hat this variet ar, but proba ate in Decemb metabolize su d 0.005, respe ge season at was given as valuated in a f while 2.2 perce or related def 0.348 and 0.0 er cooled to 5 spectively. S d in early Ma ty would be b ble, that this h ber was 0.2 ºF ugar as quickl ectively, with 1.4 percent. to whether tw future storage ent of the tube fects were ac 001, respectiv 50.0 ºF. This ucrose and g rch to help cle best held at 52 higher storag F a day from y as the Snow the sugar rela The decision wo more week e season. We ers expressed cceptable Oct vely, with a pi resulted in an lucose remai ean-up the fre 2.0 ºF or warm e temperature 52.0 to 50.0 º wden variety. ated defects b was made to ks would have eight loss num d pressure br tober through le temperatur n increase in ned elevated ee glucose in mer to preven e would redu ºF. It does no In mid-Marc being at their o sell the bin b e led to even mbers at bin u ruise and disc January. Pil re of 52.4 ºF. sucrose and through late order to imp nt cold induce ce longevity i ot appear that ch the sucrose lowest points based on this greater impro unloading we coloration und le sucrose an At this time, the pile glucose two w weeks later February. Th he pile rove chip qua ality. It ed sugars from m forming. in storage. T he pile t this variety h has the e and glucose e were s since the be eginning of s marked impr rovement. ovement. Po ssibly this re excellent a at 3.97 der the skin. he MSH228-6 r right provide we are sugge o only set 6-1 ty be planted mercial potenti 6 processed a acceptably at es a visual of t the varieties c esting that the e variety get 1 10 tubers per plant and in o at an 8-9 inch h in-row seed . ial of this line Better Made chip performa 130-140 grow order to incre d spacing on 3 Snack Foods ance. Becaus wing days from ase US#1 yie 34 inch rows. s on March 24 se the variety m planting to eld per acre w Further test 4, 2010. The y exhibited so harvest. The we are sugges ing is needed picture in me e variety sting that d to verify 159 Snack Foods s Inc. B Better Made S M MSJ126-9Y 1 1.085 SG 1 11.4 % Total 4 4.27.10 Defects 3. 3 % Color De efects 3.4 % Internal De efects in 3, MSJ1 126-9Y 9Y is an MSU eeding and G ety has moder round appea rance is stron ty is 350 cwt/A 7 -2009. The ranging from MSJ126-9Y Brothers, Inc d ground. 550 ed into the sto e variety has size tubers tha perature of 53 the U variety from ram. Genetics prog e with a rate tuber size common rance. The c 1 yield for g. The US#1 years A over three y vity is specific grav 85 in 1.076 to 1.08 by Y was grown b e, MI, on . in Greenville arvested 0 cwt. was ha orage during t the fall of f a good set o 0 to 3.25 inch at average 2.0 3.0 ºF. The va ariety was eva Bulk Bi MSJ126-9 Potato Bre This varie generally scab toler this variet from 2007 average, Michigan. Thorlund fumigated and loade 2009. Th medium s pulp temp In late De Handling apparent mid- Marc mg/g fres chips. Th to process to raise th temperatu 0.001, res to rise, as at 6.14 pe On April 2 shot of the appear to continue f well exhib 400 fewer chemical 88.6 % % Acceptable 4.7 7 % External D Defects hes in diamete aluated to be er. The stora 81 percent b age was filled bruise free. on October 2 21st with a ecember, Bin 3 Committee to from pre-harv ch. From harv h weight. Mo he amount of S s the bin. Pile he pile temper ure was 54.0 spectively. C s well as, the c ercent and 3.6 3 had a 0.974 o believe that vest sucrose v vest until earl ost concernin SED that was e temperature rature to 54.0 ºF and by mid hip related de chip defect sc 6 percent of th 4 sucrose leve this variety w values. The v ly February, t ng was the da s present was e was mainta 0 ºF in hopes d-March the s efects deceas cores. Tuber he tubers exp el and a 0.00 was slightly ch varieties’ suc he glucose le ark stem end d s so severe th ined at 52.0 º of improving t sucrose and g sed as well. F weight loss n pressed press 5 glucose lev hemically imm crose values d evel in the tub discoloration hat we wonde ºF until mid-F the overall ch glucose fell to From mid-Ma numbers at bi sure bruise an vel which led t mature at harv decreased ste bers varied be (SED) that w ered if we wer ebruary. At t hip quality. B o their lowest rch, the sucro in unloading w nd discolorati the Storage a vest. This wa eadily from ha etween 0.003 was visible in t re ever going this time, it wa y early March levels of 0.35 ose and gluco were higher t on under the and as not arvest until and 0.005 the finished to be able as decided h, the pile 59 and ose began han desired skin. 27, 2010, the e chip quality be comprise further testing biting strong c r GDD40 hea immaturity. bin was sent from this bin d of mostly st g of MSJ126-9 common scab t units than o to Better Mad . The total de tem end defe 9Y in the 201 b tolerance. 2 n an average de for proces efects are hig cts. The Stor 0-2011 storag 2009 was a co e year. This m sing. The pic gher than des rage and Han ge season. A old growing s may help to ex cture in the up ired at 11.4 p ndling Commi Agronomically eason and th xplain the ste pper right sho percent. Thes ittee would lik y, the variety he crop experi em end defect ows a snap- se defects ke to performed ienced 200- ts and 160 in 4, MSJ1 147-1 1 is an MSU b ate maturity, s gh specific gr ty. In the 200 exhibited an #1 and a high breeding line slight small s avity and long 07 to 2009 fie average yield h specific grav with a ize g-term eld trials, d of 307 vity of Utz Quality F MSJ147-1 1.099 SG 4.0 % Total 5.18.10 Foods Defects 1.0 % Color Defects 1. 0 % Internal Defects Bulk Bi MSJ147-1 medium-la profile, hig chip quali this clone cwt/A US# 1.090. MSJ147-1 and was d pulp temp this bin wa storage po arrived at to go to 50 further if c glucose v made to c sucrose v February in March a the comm Bulk Bin 4 upper righ unloading discolorat bruise bei Overall, th of this lev hard to re for varietie 1 was grown delivered on O perature of 51 as to establis otential of this the storage w 0 ºF for holdin chip quality re alues were 0 cool the pile fu values indicati and remained and the chip q mittee felt they by Sandyland October 20th w .0 ºF. The go h the long-ter s variety. MS with a 75% br ng. At this tim emained. In e .631 and 0.00 urther to 48.0 ing the induct d there for the quality contin y had reached d Farms with a oal for rm SJ147-1 ruise free ratin me, the sugar early Decemb 03, respective ºF by early J tion of sugars e duration of t ued to improv d their goal of 96.0 % % Acceptable 2. 0 % External Defects ng. The varie r profile would ber, the pile te ely. The pile c January 2010 s as a result o the storage s ve. The chip f storing this v ety was slated d be reevalua emperature w chip quality w . In January, of cooling. Th eason. The s quality of MS variety beyond d for long-term ated and the v was 50.6 ºF an was acceptab , we experien he pile was wa sucrose and g SJ147-1 was g d that of a Sn m storage and variety possib nd the sucros le, so the dec ced a rise in armed to 50.0 glucose value good in early nowden. d scheduled ly cooled e and cision was tuber 0 ºF in early es stabilized May and 4 was shipped ht depicts the g were higher tion under the ing observed d May 17th an excellent chi than desired e skin. This h at the time of at Utz Quality nd processed p color at the e time of proce ent. 7.6 perce at 6.10 perce igh level of tu uber moisture f processing. y Foods on M essing. Total ent of the tub e loss resulted May 18th 2010 l tuber weight bers expresse d in an elevate 0. The picture t loss number ed pressure br ed amount of e to the rs at bin ruise and f pressure he variety pro el of pressure emain profitab es that chip p ocessed very w e bruising. Th ble with a varie process like th well. Tuber w he agronomic ety that does his line, but ha weight loss mu c performance not yield bett ave better ag ust be manag e of this line r ter than 307 c ronomic qual ged better to r remains a con cwt/A. We ne ity. reduce the ap ncern as well. eed to continu ppearance . It becomes ue to look 161 n 5, CO950 051-7W University riety hree year om 2007- orm derate mount of r in this lossom -7W is a Colo d variety. In 2 31 cwt/A US# d average of is variety is s ype. It exhibi scab toleranc as been obse A fungicide ap White Mold pre nded. In-row o 11.5 inches. 0-18 tubers. orado State U 2009, this var #1. It has a th 303 cwt/A fro mall and unifo its some mod ce. A small am erved to occur pplication at b evention is w seed spacin . The tuber s ng should et per Herr Foods CO95051-7W W 1.087 SG 11.4 % Total 5.18.10 Defects 2.0 0 % Color Def fects 2.0 % % Internal De efects 88.6 % % Acceptable 7.4 % External D Defects Bulk Bin CO95051 developed yielded 33 US#1 yiel 2009. Th round in ty common s vine rot ha variety. A drop for W recomme be 10.5 to plant is 10 The potat on Octobe suberize a this time t determine ºF. On M sucrose v potatoes w The pictur May 18, 2 pressure 8.4 perce Herr’s. Overall, th performan oes in Bin 5 w er 22nd with a and then were the status of t ed to be 78% arch 15th, 201 value and a 0. were shipped were grown b pulp tempera e cooled at 0. the potatoes w bruise free at 10, the tubers .001 glucose d in mid-May. by Sackett Ra ature of 54.0 .2 ºF per day was reevalua t bin loading. s reached the value on reco The pile tem nch, Stanton, ºF. Upon arr until the pota ted and then In early Janu eir most stable orded. From mperature was , MI., and wer rival, the tube atoes reached cooled to 50. uary 2010, th e sugar levels this point, the s 49.6 ºF on t re harvested rs were held d a pulp temp .0 ºF for holdi e pile temper s of the storag e sucrose val he date of sh and loaded in for two weeks perature of 52 ing. The tube rature was co ge season wit ue rose stead ipping. nto storage s to .0 ºF. At ers were ooled to 50.0 th a 0.327 dily until the re at the uppe 2010. White k bruise in the e nt of the tube er right depict knot and blac external defe rs had pressu ts the overall k spot bruise ct score. The ure bruise and chip quality o was evident e overall weig d discoloratio of this load aft in the interna ght loss in this on under the s ter processing al chip defects s bin was goo skin. The bin g at Herr Foo s, as well as, od at 2.55 per processed a od, Inc. on some rcent, but acceptably at his variety has nce and some s excellent ch e potential for hip quality and r vine rot susc d processing ceptibility. potential. Of f concern is th he varieties w weak yield 162 Bulk Bin 6, Classic Russet (A95109-1) Classic Russet has looked promising in on-farm variety trials since 2007. In 2009, this variety yielded 348 cwt/A US#1 with a 1.073 specific gravity. The three year yield average for this variety is 367 cwt/A US#1. Vine maturity is medium to late. The tuber type is uniform and blocky with a Russet Norkotah type russet skin. The variety produces a nice percentage of marketable potatoes. The common scab tolerance is strong, but tuber susceptibility to Pink Eye and Pythium Leak is concerning. In row seed spacing should be kept at 9-10 inches to prevent oversized potatoes. This variety had roughly 8 percent hollow heart observed across nine trial locations in 2009. The MPIC stored about 550 cwt. of Classic Russet in 2009. The potatoes were grown at Sandyland Farms in Howard City, MI. They stored 2500 cwt. as well in their commercial storage. In the 2009 growing season, Ariel Black Leg was noted in this variety which expressed itself as stem end rot and Black Leg in the harvested tubers. At harvest, the tubers were evaluated for black spot bruise and determined to be only 67 percent bruise free. The Classic Russet was loaded into Bin 6 on October 21st, 2009, with a 54.0 ºF pulp temperature. At bin load, a large amount of Black Leg was noted in the tubers. The potatoes were held at 54.0 ºF to suberize and then the pile was cooled to 40.0 ºF as outside air was available. Shortly after bin loading, tuber quality was declining as was evident by visible wet breakdown. As the pile was cooled, the breakdown slowed and reached a manageable level. The grower was experiencing similar quality issues and shipped their potatoes shortly after storing. We managed to hold Bin 6 until December 15th, 2009, when we chose to ship them to Fresh Solutions for packaging. At load-out, the pile was reported to have lost 7.19 percent of its initial weight to dehydration. But, over 91 percent of the tubers were bruise free and less than 1 percent of the tubers with bruise had discoloration under the skin. In 2009, many reports of bacterial rot in this variety were made throughout the country, not only in commercial production, but in seed producing regions as well. This variety looked as though, initially, it would bring some good agronomic quality and tuber type to our russet industry in Michigan, but the tuber rot from Black Leg and Pythium Leak brought an end to the commercial potential of this line in Michigan. 163 Ethylene Study, Bulk Bins 8 and 9 This section is intended to provide a brief summary of the Ethylene versus CIPC study that the MPIC Storage and Handling Committee conducted over two storage seasons from 2008-2009 and 2009-2010. The general protocol was described earlier in this report. Two, 575 cwt bulk bins of Snowden potatoes were treated either with CIPC (Bin 8) or ethylene (Bin 9). The CIPC applications were described earlier. The ethylene levels and their timings were described early. Figure 1 shows the EMU and the ethylene tank configuration in the storage facility. In comparing these two sprout inhibitor products we will discuss; storage management, chip quality and sprout suppression. In both years, 2008 and 2009, the Snowden tubers arrived at the MPIC storage with elevated glucose values. Neither in 2008 nor 2009 did the control chip quality look as good as expected. There was always some background vascular discoloration and color shading in the control chips each year at the beginning of the experiment. The reduced chip quality, in both years, warranted elevated storage pile temperatures and increased fresh air inlet to facilitate the respiration of the simple sugars present in the tubers. This was feasible in the control bin, but in the treatment bin which contained ethylene gas, it was very difficult to maintain the desired amount of fresh air inlet and maintain ethylene levels at 10.0 ppm to control sprouting. Thus, the amount of fresh air was limited. Limited fresh air inlet into Bin 9 caused reduced respiration of free sugars. Also, because the inlet had to be open periodically, this made it difficult to maintain the necessary ethylene concentration to control tuber sprouting. There is a difficult trade off imposed by the ethylene product and its protocol. The ethylene system may work better in a storage environment where the inlet door is rarely opened if ever and the pile temperature is maintained between 36.0 and 42.0 ºF. It would also be ideal if the tuber sugar quality was not a factor. Both years the reduction in fresh air inlet resulted in the treatment bins having higher glucose and sucrose values when compared to the control bins. For example, in the 2009-2010 storage season, Bulk Bin 8 had sucrose and glucose values of 0.417 and 0.003, respectively, and a 34.5 percent total chip defect score on January 18th, 2010. Bin 9 had a sucrose value of 0.477 and glucose value of 0.006 with 57.2 percent of the chips with defects on this same date. It was not clear during the two storage seasons if the ethylene level in the storage was causing the elevated sugars observed or the fact that the fresh air inlet had been reduced that was causing this reduction in chip quality. Figures 3 and 5 show the chip quality, in both Bins 8 and 9 at the time of bin unloading in 2010. Table 1 shows sprout data from the 2008-2009 storage season. Sprouting in each pile was evaluated from 5 locations described earlier in the report. The table also shows the sprout results from tuber control samples taken from both bins prior to sprout treatment which were stored at 50.0 ºF. In both years, the mass of sprouts removed from the CIPC treated tubers, the amount of sprouting in both sprout length categories and the length of the longest sprouts were much smaller with the CIPC treatment than with the ethylene treatment (Tables 1-2). Figures 2 and 4 depict these results. Under these storage conditions and during both storage seasons, the CIPC sprout treatment provided the best sprout control for the tubers and the CIPC treatment resulted in the best quality chips being produced at the end of the storage seasons. 164 2008-2009 MPIC Demonstration Storage Bins 8 & 9 Snowden: CIPC and Ethylene Sprout Evaluation # of eyes # of eyes Mass of sprouts > 2mm in grams 2.00 5.67 # of eyes sprouting 2-5 mm sprouting > 5 mm 6.93 6.73 0.03 1.33 0.03 0.43 5.00 6.33 2.00 7.00 2.67 6.67 6.33 14.00 50.67 44.67 7.33 7.23 7.20 7.30 7.57 7.10 6.80 6.87 8.10 7.57 0.13 1.53 0.40 1.97 0.07 2.50 0.33 3.30 0.67 0.70 0.40 0.90 0.30 0.20 0.23 0.43 0.40 1.70 1.77 1.60 Table 1. CIPC Door MEAN Ethylene Door MEAN CIPC 10s MEAN Ethylene 10s MEAN CIPC 20s MEAN Ethylene 20s MEAN CIPC 30s MEAN Ethylene 30s MEAN CIPC Top of Pile MEAN Ethylene Top of Pile MEAN Non-Treated Snowden Bin 8 MEAN Non-Treated Snowden Bin 9 MEAN Table 2. CIPC Door MEAN Ethylene Door MEAN CIPC 10s MEAN Ethylene 10s MEAN CIPC 20s MEAN Ethylene 20s MEAN CIPC 30s MEAN Ethylene 30s MEAN CIPC Top of Pile MEAN Ethylene Top of Pile MEAN Non-Treated Snowden Bin 8 MEAN Non-Treated Snowden Bin 9 MEAN 2009-2010 MPIC Demonstration Storage Bins 8 & 9 Snowden: CIPC and Ethylene Sprout Evaluation # of eyes # of eyes Mass of sprouts > 2mm in grams 0.00 8.29 # of eyes sprouting 2-5 mm sprouting > 5 mm 7.93 8.60 0.00 6.77 0.00 0.83 1.79 7.07 0.20 8.88 0.70 6.21 7.60 17.21 NA NA 8.83 7.30 9.10 7.30 9.17 8.13 9.07 7.60 NA NA 0.17 3.37 0.03 2.83 0.13 6.20 0.57 5.83 NA NA 0.03 0.37 0.00 0.27 0.07 0.43 0.27 0.63 NA NA longest sprout length in mm 0.33 3.98 6.20 6.98 4.72 4.90 3.23 5.37 5.03 7.73 105.95 104.43 longest sprout length in mm 0.07 5.03 1.30 4.03 1.03 4.03 1.50 4.10 4.07 5.90 NA NA 165 Figure 1 . Ethylene e Managem ent Unit an nd Ethylene e Tank Figure 2 2. Snowden n tubers from m Bin 8 (CI PC Treated d) 1.28.10 Figure 3 3. Chip qual lity picture Bin 8, 1.18 .10 166 Figure 4 4. Snowden n tubers fro om Bin 9 (E thylene Tre eated) 1.28 .10 Figure 5 5. Chip qual lity picture Bin 9, 1.18 .10 167