1981 MONTCALM FARM RESEARCH REPORT MICHIGAN STATE UNIVERSITY AGRICULTURAL EXPERIMENT STATION IN COOPERATION WITH THE MICHIGAN POTATO INDUSTRY COMMISSION THE MICHIGAN POTATO INDUSTRY COMMISSION To Michigan Potato Growers and Shippers: This 1981 Potato Research Report is the result of the research that was carried on by Michigan State University at the Montcalm Research Farm, Entrican, Michigan. The continued research on Michigan potatoes is a direct result of the monies that growers and shippers have paid into the Michigan Potato Industry Commission. Only through their support can the Potato Industry in Michigan continue with similar research in the future. Thank you. Sincerely, R. H. Kaschyk Executive Director RHK:kk enclosure THE MICHIGAN POTATO INDUSTRY COMMISSION • 500 N. HOMER STREET • LANSING, MICHIGAN 48912 • (517) 373-3783 ACKNOWLEDGMENTS Research personnel working at the Montcalm Branch Experiment Station have received much assistance in various ways. A special thanks is due each of these individuals, the Michigan Potato Industry Commission, private companies and government agencies all of who have made this research possible. Many valuable con­ tributions in the way of fertilizers, chemicals, seed, equipment, technical assistance, personal services, and monetary grants were also received and are hereby gratefully acknowledge. Special recognition is given to Mr. Theron Comden for his devoted cooperation and assistance in many of the day-to-day operations. TABLE OF CONTENTS Page INTRODUCTION, WEATHER AND GENERAL MANAGEMENT................................................................... 1 Introduction of New Varieties N.R. Thompson, R.W. Chase, R. Hammerschmidt, R.B. Kitchen.................................. 4 1981 Potato Vareity Evaluations R.W. Chase, N.R. Thompson, R.B. Kitchen ........ ....................................... 8 1981 North Central Regional Trial N.R. Thompson, R.W. Chase, R.B. Kitchen ........................ ................................................................ 17 Use of Polyacrylamide Gel Electrophoresis in Potato Spindle Tuber Diagnosis R. Hammerschmidt................................. 20 Mini-Till Potatoes R.W. Chase, R.B. Kitchen .................. .................... . 22 The Effect of Storage Temperature Delayed Plantings of Cut Seed and Seed Treatment on Stand and Yield of Potatoes H.S. Potter......................................................................................................... 24 Weed Control in Potatoes W. Meggitt, R. Chase, G. Powell and R. Kitchen........................ 26 The Influence of Nematicides on Pratylenchus Penetrans and Tuber Yields of ’Atlantic’ Potatoes G. W. Bird and J. Davenport ................................................................... 29 Effect of Pre-Plant Soil Treatments on the Control of Potato Scab H. S. Potter, R.L. Ledebuhr ....... .................... ...... .................... 31 Controlled Droplet Spraying For Control of Early and Late Blight of Potatoes H. S. Potter......................................................... 33 Wireworm and White Grub Control in Potatoes A.L. Wells...................................................................................................................................................... 35 Foliar Insect Control on Potatoes A.L. Wells..................................................................................................................................................... 40 Biology and Control Strategies for Insect Pests of Potatoes E. Grafius, M.A. Otto........................................................................................................................ ...............42 Potato Irrigation Study J.M. Jenkins and M.L. Vitosh..................................................................................................... 47 Production and Management Factors to Maximize Specific Gravity and the Use of Carbohydrate Analysis to Determine Harvest Maturity and Processing Quality of Michigan Potatoes J.N. Cash, R.W. Chase........................................................................................................................ .................57 The Influence of Selected Production Management Practices on the Yield, Quality and Storability of Potatoes M.L. Vitosh, G.W. Bird, R. Hammerschmidt, R.W. Chase, E. Grafius, H.C. Olsen The Influence of Selected Production Management Inputs on Weight Loss and Market Quality of Superior Potatoes Stored Under Various Storage Environments B. F. Cargill ........... ....................................... ..... Page ......................... 81 Alcohol Production From Potato Processing Wastes C. A. Reddy and M.A. Abouzeid .......................................................... 95 Corn Hybrids, Plant Population and Irrigation E.C. Rossman, K. Dysinger................................. 100 Colored Bean Variety and Strain Testing—1981 M.W. Adams, A. Ghaderi, J. Kelly, J. Taylor, N. Glandon 106 MONTCALM BRANCH EXPERIMENT STATION RESEARCH REPORT R.W. Chase, Coordinator Department of Crop and Soil Sciences INTRODUCTION The Montcalm Branch Experiment Station was established in 1966 with the first experiments initiated in 1967. This report marks the completion of fifteen years of studies. The 40-acre facility is leased from Mr. Theron Comden and is located in west-central Michigan, one mile west of Entrican. The farm is used primarily for research on potatoes and is located in the heart of a major potato producing area. This report is designed to coordinate all of the potato research obtained during 1981. Much of the data herein reported represents projects in various stages of progress; so results and interpretations may not be final. RESULTS PRESENTED HERE SHOULD BE TREATED AS A PROGRESS REPORT ONLY as data from repeated trials are necessary before definite conclusions and recommendations can be made. WEATHER Tables 1 and 2 summarize the fourteen year temperature and rainfall data recorded at the Research Farm. Temperatures during 1981 averaged generally cooler than any of the previous years. April, however was somewhat warmer with several days reaching the 60's and 70's. The balance of the growing season was cooler than normal, particularly in July. It may be that this generally cooler temperature was a contributing factor to the favorable yields and quality and to the apparent accelerated growth of the 1981 crop. The first recorded freezing fall temperature was noted September 23. Total rainfall was normal compared with the 14 year average. April and May were higher than normal whereas June, July and August were below the average. The heavy rains occurred in October with 5.8 inches recorded on October 1. Irrigation applications of approximately one inch each were made on June 25, July 3, 6, 9, 17, 22, 27, August 3, 6 and 12. SOIL TESTS Soil test results for the general plot area were: P pH 6.0 511 K 248 Ca 853 Mg 150 Table 1. The 14 year summary of average maximum and minimum temperatures during the growing season at the Montcalm Branch Experiment Station. Year April Max April Min May Max May Min June Max June Min July Max July Min August Max August Min September September Min Max 6-month average Max 6-month average Min 62 61 56 54 53 47 54 57 48 58 62 50 50 49 37 1968 35 67 1969 35 65 1970 31 65 1971 30 70 1972 36 63 1973 36 62 1974 28 73 1975 35 63 1976 37 80 1977 31 67 1978 33 66 1979 31 69 1980 1981 56 35 64 67 14-year average 54 34 41 43 47 39 47 42 41 48 41 47 45 44 42 43 74 70 72 81 72 77 73 75 79 76 78 74 73 53 50 55 56 50 58 52 56 57 50 50 55 50 50 49 45 48 48 51 48 49 48 50 49 49 48 397350 77 517853 674769 46 empty table cell 50 49 51 54 49 48 45 44 46 53 52 47 49 74 73 70 73 69 73 68 65 70 70 75 76 70 81 82 80 80 76 80 77 79 80 77 82 77 81 58 56 57 53 57 60 56 58 53 52 57 55 58 73 74 73 76 73 74 70 70 71 75 72 71 71 55 59 60 55 57 60 57 57 58 61 56 57 58 80 80 80 82 79 79 81 80 81 85 81 82 81 81 empty table cell 71 49 75 53 57 79 56 Table 2 The 14-year summary of precipitation (inches per month) recorded during the growing season at the Montcalm Station. Year April May June July August September Total 1968 1969 1970 1971 1972 1973 1974 1975 1976 1077 1978 1979 1980 1981_ 14-year average 2.84 3.33 2.42 1.59 1.35 3.25 4.07 1.81 3.27 1.65 2.34 2.58 3.53 4.19 2.73 3.74 6.18 4.62 1.50 2.51 4.34 4.69 4.98 4.22 1.66 2.55 3.77 4.37 1.23 4.90 2.63 3.65 3.67 4.09 1.22 0.93 3.83 1.96 2.36 3.91 2.39 4.83 2.71 2.05 1.50 4.03 2.39 0.46 1.89 1.35 1.09 1.68 2.64 1.65 3.52 3.44 1.23 2.20 2.79 3.76 3.30 0.58 7.18 4.00 2.60 1.33 1.81 3.07 1.40 8.62 2.77 0.04 6.59 1.31 1.79 6.54 2.67 7.28 3.94 6.18 11.25 1.44 2.61 5.90 3.69 3.21 3.483.8219.68 4.38 17.32 18.16 28.52 11.91 19.53 19.13 23.97 25.87 15.86 17.39 16.80 12.85 21.99 19.21 3.37 FERTILIZERS USED Except for the specific fertility studies where the fertilizers are specified in the report, the following fertilizers were used on the potato plot area: Plow down Banded at planting - 20-10-10 Sidedressed at hilling - 46-0-0 - 0-0-60 200 lbs/A 500 lbs/A 150 lbs/A A one year cover crop of alfalfa was plowed down prior to plot establish­ ment. HERBICIDES Early preemergence alachlor (Lasso) at 2 lbs/A followed by a delayed preemergence application of metribuzin (Sencor) at 1/2 lb/A. DISEASE & INSECT CONTROL Temik at 3 lbs/A was applied at planting. Foliar fungicide and insecticide sprays were as follows: June 24 July 3 July 13 July 22 July 29 Aug. 7 Aug. 24 Sept. 2 Thiodan Monitor Monitor Bravo + Thiodan Bravo + Thiodan Bravo + Thiodan Bravo + Thiodan Bravo + Thiodan Several plots were topkilled prior to harvest with Paraquat at one qt/A plus X77 at 8 oz./100 gals of water. INTRODUCTION OF NEW VARIETIES N.R. Thompson, R.W. Chase, R. Hammerschmidt, R.B. Kitchen A. LEVERING SEED FARM Sixty seven different cultivars or seed sources were planted as two cut units. A few units were rogued out because of rhizoctonia or weak growth. The more common virus diseases PVY, leaf roll and spindle tuber were not detected by visual symptoms. The crop was topkilled in mid-August and harvest was completed on September 3. This procedure is followed to minimize late season virus infections. Mini bulk samples were collected for the winter testing program in Florida. Greenhouse tests will be conducted on the Russet Burbank, Katahdin, Jemseg, Onaway, Atlantic, Denali, Snowchip and G670-11 seed obtained from British Columbia to determine their freedom from PVX, PVY and spindle tuber. As testing techniques are established, it is planned to routinely test new selections that are introduced into the Levering seed plot program so that a nucleus of disease-free seed is available for the Michigan seed industry. B. MSU ADVANCED SELECTIONS Sixteen selections retained from the 8,000 new cultivars introduced in 1978 were planted in a replicated yield trial at the Montcalm Research Farm. Table 1. Several exhibited very desirable variety potential and will continue for further testing. Table 2 summarizes the culinary quality of these selections after 3 months storage at 52°F. Most of the selections remained in suitable chipping condition. Maturity has not been consistent with previous years. C. U.S.D.A. - BELTSVILLE SELECTIONS A major and continuing source of cultivars is from the USDA-Beltsville program. Eight seedlings were planted in replicated plots at the Montcalm Research Farm for two dates of harvest on August 26 and September 23. Table 3 summarizes the results of these two harvests. There was essentially no yield increase between the first and second harvest dates except for B7805-1 which is an attractive, smooth white skin potato. Specific gravity readings for these selections are generally medium to low. There was some increase in specific gravity between the first and second harvests, particularly for B8528-3, B8943-4, B8822-9 and Russet Burbank. SEVERAL NEW MICHIGAN SELECTIONS AND PERFORMANCE OF Cultivar Flesh Color Maturity Total cwt/A No. 1 cwt/A % No. 1 700-70 White 700-79 White 700-83 White 700-88 White Late Late Medium Medium 701-22 White Late 702-80 White 702-91 White Medium Medium 704-3 Golden Early 704-10 Golden Medium 704-17 White 709-21 White 714-10 White 716-15 White 718-6 718-11 White Golden 719-38 White Onaway White Superior White Atlantic White Monona White Medium Medium Medium Medium Late Early Early Early Early Late Late 536 371 552 368 336 406 542 349 385 431 306 367 367 358 336 388 495 403 408 335 467 332 485 283 322 359 479 306 324 400 281 300 326 339 287 353 458 373 367 296 87.1 89.5 87.9 76.9 95.8 88.4 88.4 87.7 84.1 92.8 91.8 81.7 88.8 94.7 85.4 91.0 92.5 92.6 90.0 88.4 % Over 3 1/4 8.8 1.8 13.4 17.3 20.8 6.1 7.3 13.4 5.5 23.5 21.7 2.7 5.5 36.9 4.2 11.0 26.2 2.1 12.8 11.1 Specific Gravity Chip Rating Comments 1.089 1.087 1.081 1.069 1.086 1.075 1.084 1.073 1.085 1.082 1.074 1.077 1.092 1.083 1.079 1.078 1.066 1.075 1.090 1.071 1.5 1.0 1.5 3.0 1.5 1.0 1.5 2.0 2.0 2.5 2.5 3.0 1.5 1.5 1.0 2.0 4.5 2.0 1.5 1.0 Eyes slightly deep Smooth, uniform Smooth, uniform Pointed, rough Smooth, uniform Deep eyes, blocky Tendency to pointed shape Smooth, some sungreen Small run Some scab Over-size, rough Smooth, small run Smooth, uniform Smooth, uniform Smooth, uniform Smooth, uniform Slight greening Rough skin Smooth Rough TABLE 2. THE AFTER-COOKING-DARKENING1 (ACD) AND CHIP RATING2 OF SEVERAL NEW MICHIGAN SELECTIONS STORED 3 MONTHS AT 52°F Selection Hours After * Cooking 0 Hours After * Cooking 1 Hours After * Cooking 24 Chip* Score 700-70 700-79 700-83 700-88 701-22 702-80 702-91 704-3 704-10 704-17 709-21 714-10 716-15 718-6 718-11 719-38 Onaway Superior Atlantic Monona 1.0 1.5 1.0 1.0 1.0 1.0 1.5 1.0 1.0 1.0 1.5 1.5 1.0 1.5 1.5 1.0 1.5 1.0 1.5 1.0 1.5 2.0 1.5 1.0 1.5 1.5 1.5 1.0 1.0 2.0 2.5 1.5 1.5 2.5 2.5 1.0 3.5 2.0 1.5 2.0 1.5 2.0 2.0 1.0 2.0 1.5 1.5 1.0 1.0 2.0 3.0 1.5 1.5 3.0 2.5 1.0 3.5 2.0 2.0 2.0 1.0 1.0 1.5 2.0 1.5 1.0 1.0 3.0 2.0 2.0 1.5 4.0 1.0 1.0 1.0 2.0 4.0 1.5 1.0 1.0 1ACD scored on a 1-5 scale. 1 = clear with no darkening; 5 = undesirable grayish-black discoloration throughout the cooked flesh. 2Chip rating based on a 1-5 scale. 1 = light and very acceptable color; 5 = dark and not acceptable *Determinations made December 17 and December 23, respectively. TABLE 3. THE YIELD, SIZE DISTRIBUTION & SPECIFIC GRAVITY OF SEVERAL USDA-BELTSVILLE SELECTIONS HARVESTED ON TWO DATES. MEF 1981 September 23, 1981 Yield (cwt/A) Total September 23, 1981 Yield (cwt/A) No. 1 September 23, 1981 Percent size distribution 2-3 1/4 September 23, 1981 September 23, 1981 Percent size distribution Percent size distribution Over 3 1/4 B's September 23, 1981 September 23, 1981 Specific Gravity Percent size distribution Pick outs Empty table cell August 26, 1981 Yield (cwt/A) Total August 26, 1981 Yield (cwt/A) No. 1 August 26, 1981 Percent size distribution 2-3 1/4 August 26, 1981 August 26, 1981 Percent size Percent size distribution distribution Over 3 1/4 B's August 26, 1981 Percent size distribution Pick outs August 26, 1981 Specific Gravity B7154-10 B7516-7 B7805-1 B8528-3 B8934-4 B8943-4 B8972-1 B8822-9 R. Burbank Superior Average 471 312 417 320 309 295 273 359 376 321 345 386 275 385 262 239 207 137 242 287 278 270 82 86 86 82 75 70 51 68 76 87 Empty table cell 0 2 7 0 2 0 0 0 1 0 Empty table cell 16 12 5 16 18 30 47 30 22 12 Empty table cell 2 0 2 2 5 0 2 2 1 1 Empty table cell 1.060 1.077 1.070 1.069 1.067 1.066 1.073 1.060 1.071 1.070 457 303 473 337 309 315 263 339 406 324 399 259 462 261 229 220 125 212 292 289 87 83 80 76 74 70 47 63 61 88 1 3 18 1 1 0 0 0 11 1 11 14 2 23 24 29 53 37 21 11 1 0 0 0 1 1 0 0 7 0 1.068 352 275 Empty table cell Empty table cell Empty table cell Empty table cell 1.063 1.077 1.074 1.075 1.067 1.074 1.075 1.066 1.079 1.071 1.072 Planted: May 6, 1981 Fertilizer: 200 lbs/A 0-0-60 plowdown 500 lbs/A 20-10-10 planter + temik 3 lbs/A 200 lbs/A 45-0-0 1981 POTATO VARIETY EVALUATIONS R.W. Chase, N.R. Thompson, R.B. Kitchen Department of Crop and Soil Sciences A. Dates of Harvest of Several Potato Varieties The intensive dates-of-harvest study is conducted each year at the Montcalm Research Farm. Three blocks, each containing 112 ten foot plots were planted May 6, 1981. Each block contained 28 varieties and advanced selections planted in a randomized complete block design with four replications. One block was harvested August 11, a second on August 31 and the third on September 22. At each date, yields, specific gravity and chip scores were determined. The plot area received 200 lbs/A plow down of 0-0-60, 500 lbs/A 20-10-10 and 150 lbs/A 45-0-0 sidedressed. The plowdown crop was a one year old stand of alfalfa. Temik at 20 Ibs/A was applied at planting. Alachlor (Lasso) 2 Ibs/A was applied soon after planting as early preemergence and metribrizen (Sencor) 0.5 lbs/A was applied delayed preemergence. The plots were irrigated. Results The yield performance at each date of harvest is summarized in Table 1. There was no yield increase between the second and third harvest which was due in part to an increased rate of growth during the season so that many varieties appeared to mature earlier than normal. There also was a definite curtailment in growth in September after the application of copper. Yields in general were very desirable. Varieties which produced very acceptable yields before September were Atlantic, Crystal, Belchip, Onaway, Pioneer, Rideau, MS402-1, MS108-5, and Wis 718. Chipbelle, Denali, Lemhi, Michimac, Monona, Russet Burbank and CA027 would be judged as later maturing varieties. Table 2 summarizes the specific gravity and chip quality of each variety. Overall there was no appreciable change in specific gravity between harvests. Varieties which show exceptionally high specific gravity are Chipbelle, Denali and Atlantic. All varieties except Onaway produced acceptable chips at most harvests. Several of the later maturing varieties produced darker chips at the early harvest, particularly if held for one week. Table 3 summarizes the internal and external defects which were observed. Hollow heart, growth cracks and second growth were all minimal. Vascular discolorations were observed in most varieties, however for the most part these were only slight. Dakchip exhibited the most severe vascular discoloration. Variety Observations Allagash Russet - yields were below average at all harvests, primarily reflecting a lack of adequate tuber sizing. Specific gravity is also low. Similar results were noted in 1980. Atlantic - continues to produce very satisfactory yields and consistently high specific gravity. It produces very acceptable potato chips and it appears to be a variety with a fairly wide range in marketable harvest. With its wide adaptability including the southern states, this variety could become a year-around chipping variety. Belchip - yielded well above the average with medium-high specific gravity. Tuber type and appearance were very good in 1981 and defects were minimal. Maturity is somewhat later than Atlantic. Chipbelle - appears to be a late maturing variety with exceptionally high specific gravity at each harvest and above average yields. Tuber shape is oval to oblong. The plant is very susceptible to metribuzin (Lexone/Sencor). Chip color has been very good and comparable to Monona and Atlantic. Crystal - appears to set and size tubers early. Tubers have a bright skin, however if scab is present it is often the deep and pitted scab. Bruising and susceptibility to storage problems have been reported. Dakchip - yields were above average, however specific gravity is medium to low and it did decline with delayed harvest. Vascular discoloration was severe and this has been noted in previous years. It has a very short dormancy. Denali - a late maturing variety which yielded well above average. Specific gravity is very high. It has a low tolerance to scab and fields with a history of scab should be avoided. Highlat Russet - exceptionally low yields with inadequate tuber sizing. Released from Alaska in 1980 for specific markets in Alaska. It does not appear to be well adapted to Michigan. Jemseg - an early maturing round white with some skin netting. Yields were below average. Lemhi - yields were well above average and tuber type and shape were very attractive with a higher percentage of U.S. No. l's than Russet Burbank. It appears to size tubers earlier than Russet Burbank, however hollow heart and blackspot are two serious problems at this point. Michimac - a late maturing round white with high yields. Appears most suitable for fresh pack from a later harvest or out of storage. Appears to have a low tolerance to scab. Monona - included as a check variety. Yields were average at the late harvest. Specific gravity was low and chip quality was excellent. Oceania - yields were slightly below average. Tubers are attractive with shallow eyes and it has low specific gravity. Would appear most suitable for fresh pack. Onaway - included as a check variety. Yields well above average and type was very good. Pioneer - a long red variety being evaluated as a potential for early harvest frozen processing. Sets and sizes tubers early with very good yields. Rideau - a medium-late round red variety with very good color. Yields above average at the later harvests. Russette - yields were slightly below average. During both 1980 and 1981 hollow heart has been prevalent in this variety although it was not observed in these plots. Russet Burbank - included as a late maturing check variety. Sizing did not continue after the second harvest which is not normal. Tuber type and quality were very good in 1981. Superior - yields were very good in 1981. Yukon - a golden flesh variety which has good yields and very acceptable tuber shape and appearance. Specific gravity readings were consistently above 1.080. B8972-1 - a russet selection from the USDA-Beltsville program. Tuber sizing was very poor with a high percentage of tubers under 2 inch at all harvests. Yields were very low. CA-027 - is a late maturing selection from Maine. It yields well above average and appears most suitable as a fresh pack potato. C-13 - is an advanced selection from the Campbell Co. Yields were below average however tuber shape and appearance were very good. MS108—5 — is an advanced selection which yielded well above average. Individual tuber sizing is not adequate and at locations where there is a stress, the percentage of tubers under 2 inch increases rapidly. The selection is being deleted. MS401-2 - matures early and produces tubers which are smooth and sized well. It has a low specific gravity. MS402-1 - medium maturity with average yields. Tubers sized well and were smooth and well shaped. It has been observed to have some tolerance to scab at some locations. MS402-5 - has yielded below average and will be deleted. Wis 718 - yielded exceptionally well with a high percentage of tubers over 3 1/4 inch. On larger tubers hollow heart has been observed. Specific gravity is low and it appears most suited to the fresh pack market. TABLE 1 THE YIELD & SIZE DISTRIBUTION OF SEVERAL POTATO VARIETIES HARVESTED ON 3 SEPARATE DATES MEF 1981 Harvest Date August 11 August 11August 11August 11August 11August 31 August 31August 31August 31August 31September 22September 22 September 22 September 22 September 22 Variety Allagash R. Atlantic Belchip Chipbelle Crystal Dakchip Denali Highlat Jemseg Lemhi Michimac Monona Oceania Onaway Pioneer Rideau Russette R. Burbank Superior Yukon B8972-1 CA 027 C13 MS 108-5 MS 401-2 MS 402-1 MS 402-5 WIS 718 Average Total (cwt/A) No.l (cwt/A) 2"-10oz Percent 280 423 321 363 409 359 332 203 253 350 323 288 351 388 430 307 292 280 277 309 280 282 334 378 232 352 303 367 324 229 376 296 334 350 313 305 136 230 298 298 261 319 373 390 290 263 215 252 286 188 240 311 306 203 327 246 340 285 81 82 89 88 84 85 87 67 88 77 90 87 87 84 72 93 85 77 94 89 67 81 79 81 88 90 79 89 empty table cell Over Percent l0oz Percent B's Total (cwt/A) No.l (cwt/A) 2"-10oz Percent Over Percent l0oz Percent B's Total (cwt/A) No.l (cwt/A) 2"-10oz Percent Over Percent l0oz B's Percent 0 7 3 4 4 2 4 0 2 8 2 3 3 12 19 2 5 0 0 4 0 5 14 0 0 3 19 9 8 8 15 12 9 33 9 14 8 10 9 4 9 6 8 19 6 7 33 14 6 19 12 6 274 471 440 415 484 401 455 261 311 459 467 338 367 442 471 455 34'6 375 330 357 261 417 330 470 244 392 2 3 19 8 334 524 empty table cell empty table cell 389 223 440 403 377 421 358 426 184 288 394 432 313 319 422 434 439 323 286 305 332 157 396 305 400 205 357 292 507 348 81 82 79 89 86 87 88 70 87 65 82 86 80 85 83 84 85 71 90 85 60 88 84 84 84 86 86 59 empty table cell 0 11 13 2 1 3 6 0 5 20 10 6 7 10 9 12 8 5 2 8 0 7 8 0 0 5 18. 7 7 9 13 10 7 29 6 13 8 7 13 5 7 3 6 18 7 6 40 5 7 14 15 9 278 451 421 451 485 393 476 223 277 499 477 395 385 426 479 413 359 370 335 351 256 488 287 501 250 343 13 5 349 1 36 512 empty table cell empty table cell 390 217 412 385 413 432 329 431 148 248 427 434 363 356 402 435 385 326 287 298 328 126 452 257 421 201 309 295 487 343 78 86 76 89 86 78 86 66 85 72 87 85 86 73 78 76 89 75 89 82 50 81 65 84 81 86 84 75 0 5 15 3 3 6 4 0 5 13 4 8 6 21 13 17 2 3 0 12 0 11 24 0 0 4 0 20 22 9 9 7 10 16 8 34 10 13 9 6 8 5 9 5 9 20 10 6 50 6 9 16 19 9 16 5 empty table cell empty table cell empty table cell TABLE 2. THE SPECIFIC GRAVITY & CHIP QUALITY OF SEVERAL POTATO VARIETIES HARVESTED ON 3 SEPARATE DATES MEF-1981 Harvest Date Variety August 11 Specific Gravity Allagash R. 1.071 August 11 August 11 chip score* 1 day 1.0 chip score* 7 days 1.5 1.066 August 31 Specific Gravity chip August 31 score* 1 day 1.0 August 31 September 22 chip Specific Gravity score* 7 days 1.0 1.068 September 22 chip score* November 19 1.5 Atlantic Belchip Chipbelle Crystal Dakchip Denali Highlat Jemseg Lemhi Michimac Monona Oceania Onaway Pioneer Rideau Russette R. Burbank Superior Yukon B8972-1 CA 027 C13 MS108-5 MS401-2 MS402-1 MS402-5 WIS718 1.077 Average *chip score based on 1-5 scale 1= light & very acceptable; 5 = dark and not acceptable 1.0 1.0 1.5 1.5 1.0 1.0 1.0 1.5 2.5 2.0 1.0 2.0 3.0 1.5 2.5 2.0 2.5 1.5 1.5 1.0 1.5 1.0 1.0 1.0 1.0 1.0 1.5 empty table cell empty table cell 1.094 1.085 1.100 1.074 1.077 1.093 1.069 1.073 1.081 1.072 1.070 1.068 1.070 1.075 1.076 1.079 1.079 1.077 1.085 1.079 1.078 1.083 1.082 1.071 1.071 1.082 1.073 1.078 1.091 1.080 1.100 1.074 1.073 1.093 1.067 1.074 1.084 1.073 1.068 1.066 1.068 1.076 1.078 1.081 1.080 1.075 1.082 1.079 1.082 1.074 1.084 1.071 1.071 1.075 1.066 1.077 1.091 1.083 1.100 1.079 1.069 1.094 1.066 1.072 1.084 1.069 1.071 1.065 1.065 1.075 1.077 1.081 1.078 1.076 1.084 1.076 1.079 1.077 1.082 1.071 1.069 1.077 1.0 1.0 1.0 1.0 1.0 1.0 1.5 1.0 1.0 1.0. 1.0 1.0 3.0 1.5 1.5 1.5 1.5 1.5 1.0 1.0 1.0 1.0 1.5 1.0 1.0 1.0 1.0 2.5 1.5 2.0 2.5 1.5 2.0 2.0 2.0 3.0 3.0 1.0 2.0 4.0 2.5 2.0 2.0 2.5 1.5 1.5 2.0 3.0 1.0 2.0 1.0 1.5 1.0 1.5 1.0 1.0 1.0 1.5 1.0 1.5 1.5 1.5 1.0 2.0 1.0 1.0 3.0 1.5 1.5 1.5 2.5 1.5 1.5 1.5 1.0 1.0 1.5 1.0 1.5 1.0 1.5 ----- empty table cell empty table cell 1.0 1.0 1.0 1.5 2.0 1.5 2.5 3.5 1.5 2.0 1.0 2.0 4.0 1.5 2.5 3.5 3.0 1.5 2.0 1.5 1.5 1.5 2.5 3.0 1.5 1.5 empty table cell empty table cell TABLE 3. THE INCIDENCE OF EXTERNAL* & INTERNAL DEFECTS* ON SEVERAL POTATO VARIETIES MEF 1981 Internal Internal Necrosis --- Variety External Second Growth Allagash R. Atlantic Belchip Chipbelle Crystal Dakchip Denali Highlat Jemseg Lemhi Michimac Monona Oceania Onaway Pioneer Rideau Russette R. Burbank Superior Yukon B8972-1 CA 027 C 13 MS 108-5 MS401-2 MS402-1 MS402-5 WIS 718 * Based on observations of 25 tubers selected at random from the Sept. 22 harvest. sl = slight; sev = severe; br = brown External ScabInternal Vascular Discoloration --- 2 sl 2 sl, 2 sev 4 sl 2 sl 2 sl, 12 sev 1 sl, 1 sev 2 sl 1 sl 4 sl 4 sl, 5 sev 2 sl 1 sl 2 sl --- 2 sl --- 3 sl 2 sl 3 sl 2 sl 9 sl 2 sl --- --- --- 3 sl, 1 sev --- External Growth Crack --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 1 --- --- --- --- --- --- --- 1 --- --- --- --- --- --- --- 1 --- --- --- --- 1 --- --- --- --- --- 1 --- --- 1 --- --- --- --- --- 1 --- --- --- --- 1 --- --- --- --- --- --- --- --- --- --- --- --- --- 1 --- --- 1 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 1 br center --- --- --- --- 1 br center --- --- --- --- --- --- --- --- Internal Hollow Heart --- --- --- --- --- --- --- --- --- 1 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- Storage evaluations Table 4 summarizes the culinary quality of these several varieties after 3 months storage at 52F. Generally speaking after-cooking-darkening (ACD) ratings were poorer than other years. In some varieties such as Atlantic, Crystal, Denali, Oceania, Onaway, Pioneer, Rideau, Russet Burbank, Superior, Yukon, B8972-1 and Cl3 the cooking quality in terms of color was very desirable. Varieties with high specific gravity such as Atlantic, Chipbelle and Denali tend to slough more than do varieties with lower dry matter. Several varieties had the ACD confined to the area outside of the vascular ring and generally was most pronounced on the stem end, which is very typical of this reaction. Similiar samples stored at 40° will be evaluated in February. Several of the selections remained in very acceptable chipping condition during this storage period. Atlantic, Belchip, Monona, Chipbelle and Allagash Russet remained in the most desirable chipping condition and were closely followed by Crystal, Denali, Superior, B8972-1, C-13, CA 027, MS402-5, Dakchip and Lemhi. Dakchip was badly sprouted at the end of the storage period and of all these varieties displayed the shortest rest period. Similiar samples have also been stored at 40F and these will be removed in February for reconditioning and the determination of their ability to produce an acceptable chip color. Table 4. The after-cooking-darkening1 and chip rating2 of several varieties held in storage at 52°F Variety Hours after cooking 0 Hours after cooking 1 Chip score Hours after cooking 24 1.0 1.5 1.5 2.0 1.0 1.5 1.5 1.0 1.5 1.0 2.0 1.0 1.0 1.0 1.5 1.0 1.5 1.0 1.0 1.0 1.0 3.0 1.0 1.5 1.0 1.0 1.0 Allagash Russet Atlantic Belchip Chipbelle Crystal Dakchip Denali Highlat Jemseg Lemhi Michimac Monona Oceania Onaway Pioneer Rideau Russette R. Burbank Superior Yukon B8972-1 CA 027 C 13 MS 108-5 MS 401-2 MS402-1 MS402-5 1Ratings based on a 1-5 scale. 1 = clear with no after cooking darkening 5 = undesirable greyish black discoloration throughout the flesh 2Chip score based on a 1-5 scale. 1 = light color and very acceptable 5 = dark color and not acceptable 1.0 1.0 1.0 1.0 1.5 1.5 1.5 2.0 3.5 1.5 3.5 1.0 2.0 4.0 2.5 3.0 3.0 3.5 1.5 3.0 1.5 1.5 1.5 2.5 3.0 2.5 1.5 2.0 1.5 2.0 3.0 1.0 2.0 1.5 1.5 2.0 2.0 3.5 2.0 1.5 1.5 1.5 1.5 2.0 1.0 1.5 1.0 1.5 3.0 1.5 2.0 2.0 2.0 1.5 3.5 1.5 2.5 3.0 1.0 2.0 1.5 2.0 2.0 2.0 3.5 2.0 1.5 1.5 1.5 1.5 2.0 1.0 1.5 1.0 1.5 3.5 1.5 2.0 2.0 2.0 1.5 B. 10 Hill Observation Plots Very few selections were planted in 10 hill observation plots as most seed was sufficient enough to plant in a replicated plot. Following are the four selections observed in a single 10 hill plot. Percent Over 3 1/4 Percent Under 2'' US No. 1 cwt/A Selection Total cwt/A Percent 2-3 1/4 Shepody Snowchip G 670-11 B 8833-6 390 538 577 257 335 484 546 156 C. Overstate Potato Variety Trials 10 9 3 36 10 0 27 0 76 90 68 61 Overstate potato variety trials are planted as single row, result­ demonstration plots in order to incorporate commercial handling of the seed and harvest. Plots were established at DuRussel Brothers in Manchester, Gordon Corrion in Munger, Leroy Woloszyk in Posen, Hank and Andy Leep at Shelbyville, and Carl and George Horkey at Dundee. Half acre plantings of several varieties were also evaluated at the Wayne Lennard Farm in Samaria. Except at the Lennard Farm, approximately 35 pounds of seed of each variety was provided to the cooperating grower. The seed was cut in their mechanical cutter and then planted with their planter. The results are summarized in Table 5. Data from the Corrion and Horkey Farms are not included because of water damage to the plots during September and October. There was a significant range in climatic conditions between locations. Extremely dry conditions prevailed during the growing season in the northern Lower Peninsula and this is reflected in the lower yields and high specific gravity at the Woloszyk Farm. Varieties which seemed to yield consistently well were Atlantic, Chipbelle, Crystal, Denali and Wis 718. Scab was very prevelant with the plot area at Allegan and was most severe on Crystal, Denali and Dakchip. When scab is present it frequently appears as the deep, pitted type on the Crystal variety. Dakchip has not yielded well and vascular discolorations have been frequently observed. Internal defects were less in 1981 than in 1980. Hollow heart was observed on Wis 718, Russette, Allagash Russet, Lemhi and Atlantic. Russette, Oceania and Rideau were observed to be slower in emergence and in early season vigor. Table 5. The yield and specific gravity of several potato varieties grown at out-state locations in 1981. Variety Leep Allegan County Total (cwt/A) Leep Allegan County No. 1 (cwt/A) Leep Allegan County Specific Gravity Woloszyk Presque DuRussel DuRussel Washtenaw County Washtenaw County Isle County Total (cwt/A) No. 1 Specific Gravity (cwt/A) empty table cellempty table cellempty table cellempty table cellempty table cell 220 Woloszyk Presque Isle County Total (cwt/A) Woloszyk Presque Isle County No. 1 (cwt/A) 186 1.058 DuRussel Washtenaw County Specific Gravity Lennard Monroe County Total (cwt/A) Lennard Monroe County Specific Gravity empty table cellempty table cell 420 empty table cell 405 empty table cellempty table cell empty table cellempty table cellempty table cellempty table cellempty table cellempty table cellempty table cell empty table cell empty table cell 1.093 1.082 240 222 Allagash Russet empty table cell Atlantic Belchip Chipbelle Crystal Dakchip Denali Katahdin Lemhi Michimac Oceania Ontario Rideau Russette B 7805-1 CA 027 MS 108-5 MS 402-1 Wis 718 Average 371 401 333 453 empty table cell empty table cell empty table cell 292 empty table cell empty table cell empty table cell empty table cell empty table cell 400 302 empty table cell 372 297 352 312 346 226 288 1.083 1.078 1.084 1.070 1.065 1.087 328 374 320 443 1.085 1.070 1.065 1.083 260 217 240 176 1.089 1.086 209 406 194 381 1.077 1.064 empty table cellempty table cellempty table cellempty table cellempty table cell empty table cell 199 394 empty table cellempty table cellempty table cellempty table cellempty table cell 276 empty table cellempty table cellempty table cellempty table cellempty table cell 354 empty table cellempty table cell 1.093 1.074 304 263 165 363 265 319 1.081 1.066 1.076 empty table cellempty table cell 284 1.073 empty table cellempty table cell empty table cellempty table cellempty table cell 272 1.066 empty table cellempty table cellempty table cell 261 231 1.057 334 1.066 empty table cellempty table cell empty table cellempty table cell 287 empty table cellempty table cell 348 empty table cellempty table cellempty table cellempty table cellempty table cell 328 empty table cellempty table cell 1.074 1.077 1.090 254 145 199 213 135 171 222 219 184 207 168 164 1.084 1.086 1.078 364 289 1.072 1.062 278 447 empty table cellempty table cellempty table cellempty table cellempty table cell 368 349 1.084 1.073 222 193 321 empty table cellempty table cell empty table cellempty table cellempty table cell empty table cellempty table cell 273 293 271 247 392 345 289 1.066 1.066 1.064 1.069 1.065 1.057 1.067 289 1.077 empty table cellempty table cell empty table cellempty table cellempty table cell empty table cellempty table cell 319 311 305 1.063 1.063 1.074 empty table cellempty table cell Planted: May 15, 1981 May 15, 1981May 15, 1981May 14, 1981May 14, 1981May 14, 1981May 29, 191May 29, 191May 29, 191April 5, 1981April 5, 1981 Harvested: September 28, 1981September 28, 1981 September 28, 1981 September 24, 1981 September 24, 1981 September 24, 1981 October 12, 1981October 12, 1981 October 12, 1981 September 10, 1981 September 10, 1981 1981 NORTH CENTRAL REGIONAL TRIAL N.R. Thompson, R.W. Chase, R.B. Kitchen Department of Crop and Soil Sciences The North Central Regional Trials are conducted each year at 12 locations throughout the North Central region which includes Alberta and Manitoba. These trials are designed to provide a performance evaluation of advanced selections from the plant breeding programs of Nebraska, Minnesota, North Dakota, Louisiana, Wisconsin and Michigan. Thirteen entries were evaluated in 1981 and were compared with Norland, Red Pontiac, Norchip and Russet Burbank. Characteristics of the 1981 entries are as follows: SELECTION NO. Neb. A129.69-1 Neb. A219.70-3 Neb. 7.67-1 Minn. 9781 Minn. 8777 Minn. 10162 La. 7196 La. 31-124 Wisc. 726 Wisc. 774R ND146-4R ND119-3 ND55-7 Norland Red Pontiac Norchip Russet Burbank PARENTAGE Platte x 48.60-1435 Sioux x 49.62-5 45.51-3 x White Cloud 2911.69-1 x 2912.69-3 32.63-9 x ND6948-14R Nooksack x 2848.72-4 11-74 (X) Minn. 1317 x 71-110 Wisc. 639 x Kennebec La. 12-8 x ND6948-14R ND8987-3R x ND9403-20R ND8750-20 x Wischip B7633-6 x Wischip CHECK CHECK CHECK CHECK MATURITY Late Medium Medium Medium Late Medium Late Medium Med-Late Med-Late Early Medium Late Early Late Medium Late OTHER INFORMATION COLOR Chips White Chips, Scab Resistant White Chips, Scab Resistant White Chips, Scab Resistant,Long Russet Late Blight Resistant Red Late Blight Resistant White Scab resistant, chips White White Chips empty table cell White empty table cell Red Chips, Late Blight resist. Red Chips White Chips White empty table cell Red empty table cell Red White Chips Russet empty table cell The performance results are shown in Tables 1 and 2. Table 1. THE YIELD PERFORMANCE OF SEVERAL ADVANCED SEEDLINGS IN THE 1981 NORTH CENTRAL REGIONAL TRIAL Most2/ Representa­ tive Scab Area-Type Aver.1/ Mat. Early to Medium Early 2.0 Early to Medium Early empty table cell 347 empty table cell 2.0 CWT/A Aver. Yield CWT/A Aver. Yield US #1 Early to Medium Early 286 Early5/ Aver. Chip4/ Total Blight Color Solids Reading Early to Medium Early Early to Medium Early Early to Medium Early Early to Medium Early Early to Medium Early smooth but small empty table cellempty table cell 2 82.4 17.1 empty table cell eyes deeper than normal Early to Medium Early 3 334 300 89.8 Aver. Percent US #1 Gen.3/ Merit Rating 15.4 empty table cell 3 Comments and General Notes Medium to Late Medium to Late Medium to Late Medium to Late Medium to Late Medium to Late Medium to Late Medium to Late Medium to Late Medium to Late empty table cell Smooth, uniform 4.0 empty table cell 322 90.6 18.2 292 1 3 Variety Early to Medium Early ND146-4R Norland Medium to Late Neb. A129.69-1 Neb. A219.70-3 Neb. 7.67-1 Minn. 9781 Minn. 8777 Minn. 10162 Wisc. 726 Wisc. 774R La. 7196 La. 31-124 ND 119-3 ND 55-7 Red Pontiac Russet Burbank Norchip empty 584 table cell empty table cell 273 empty table cell 230 table cell 545 empty 3.0 3.0 2.5 3.5 3.0 3.5 306 3.5 empty table cell 458 3.0 empty table cell 3.5 2.5 3.5 4.5 4.5 3.0 579 236 123 524 1-3 193 152 291 413 372 327 336 empty table cell 364 188 empty table cell 229 empty table 222 cell 283 empty 599 650 table cell empty table cell 411 300 empty table cell 332 382 empty table cell 2 5 99.1 17.7 86.4 53.4 96.1 78.7 95.0 90.1 87.9 91.3 82.0 78.4 92.1 16.2 empty table cell 2 18.4 empty table cell 2.5 18.4 2.5 18.4 empty table cell 1 18.2 1.5 16.9 empty table cell 4 18.2 empty table cell 3 17.1 empty table cell 2.5 16.2 18.0 empty table cell 17.1 19.2 1 1.5 4.5 4 empty table cell empty table cell 3.5empty table cell wide variation in size empty table cell deep eyes empty table cell small, long, round empty table cell smooth, shallow eyes empty a few stitched ends empty table cell table cell pointed mishape empty table cell large, rough empty table cell pointed empty table cell long, round, pointed empty table cell deep eyes, sprouted empty table cell irregular shapes empty table cell rough 72.9 86.9 19.2 empty table cell 1.5 empty table cell very irregular shape empty table cell 3 empty table cell misshaped 1/ 1-Very Early-Norland maturity; 2-Early-Irish Cobbler maturity; 3-Medium-Red Pontiac maturity; 4-Late-Katahdin maturity; 5-Very Late-Kennebec or Russet Burbank maturity. 2/ AREA - T-less than 1%; 1 - 1-20%; 2 - 21-40%; 3 - 41-60%; 4 - 61-80%; 5 - 81-100%. TYPE - 1. Small, superficial 2. Larger, superficial; 3. Larger, rough pustules; 4. Larger pustules, shallow holes; 5. Very large pustules, deep holes. 3/ Place top five among all entries including check varieties; disregard maturity classification. (Rate first, second, third, fourth and fifth (in order) for overall worth as a variety. 4/ Chip Color - PCII Color Chart 1-5 scale 1 = lightest 5 = dark 5/ Early Blight - 1-suspectible; 5-highly resistant. Table 2. THE SUMMARY OF EXTERNAL AND internal defects of several advanced selections IN THE 1981 NORTH Percent Internal Defects (2) Vascular Normal Tubers (5) 100 Early to Medium Early 97 Medium to Late Percent Internal Defects (2) Percent Internal Defects (2) Hollow Heart Internal Necrosis Early to Medium Early empty table cell empty table cell3 Discoloration Early to Medium Early empty table cell empty table cell Scab (3) Early to Medium Early empty table cell empty table cell4 Medium to Late empty table cell5 empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell4 empty table cell8 empty table cell empty table cell5 empty table cell6 empty table cell8 empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell Tubers Free Total (4) Percent External Defects (1) Sun of External Green Defects Early to Medium Early Early to Medium Early Early to Medium Early empty table cell empty table cell96 Medium to Late Percent External Defects (1) Second Growth Early to Medium Early 97 empty table cell empty table cell Medium to Late Medium to Late Medium to Late empty table cell4 empty table cell empty table cell empty table cell empty table cell empty table cell4 empty table cell empty table cell2 empty table cell empty table cell empty table cell empty table cell Variety Early to Medium Early ND146-4R Norland Medium to Late Neb. A129.69-1 Neb. A219.70-3 Neb. 7.67-1 Minn. 9781 Minn. 8777 Minn. 10162 Wisc. 726 Wisc. 774R La. 7196 La. 31-124 ND 119-3 ND 55-7 Red Pontiac Russet Burbank Norchip (1) Based on four 25 tuber samples (one from each replication). Percentage based on number of tubers. (2) Based on four 25 tuber samples (one from each replication). Percentage based on number of tubers. (3) Includes all tubers with scab lesions whether merely surface, pitted or otherwise and regardless of area. Be sure to (4) This total - tubers free from any external defect of any sort. (5) Percentage normal tubers are those showing no internal defects. Some individual tubers will have more than one type Early to Medium Early empty table cell Medium to LateMedium to Late empty table cell empty table cell empty table cell 8 empty table cell 8 2 empty table cell 18 4 empty table cell 12 empty table cell 6 empty table cell 9 empty table cell 10 16 empty table cell empty table cell 19 empty table cell empty table cell empty table cell empty table cell empty table cell2 empty table cell empty table cell1 empty table cell empty table cell empty table cell empty table cell empty table cell11 empty table cell empty table cell empty table cell empty table cell empty table cell 91 100 100 88 100 79 89 98 90 empty table cell96 empty table cell92 empty table cell 100 empty table cell93 empty table cell69 11 10 count tubers with any amount of scab in this category. 7 empty table cell 93 95 92 92 97 82 96 88 94 91 90 78 87 81 93 5 12 4 31 4 3 86 4 7 CENTRAL REGIONAL TRIAL Percent External Defects (1) Percent External Defects (1) Growth Cracks 3 Medium to Late 20 12 of internal defects. USE OF POLYACRYLAMIDE GEL ELECTROPHORESIS IN POTATO SPINDLE TUBER DIAGNOSIS Department of Botany and Plant Pathology R. Hammerschmidt Introduction Potato spindle tuber disease has the potential of being a limiting factor in production due to yield losses and rejection of seed material. Since the disease is tuber borne, it is very important that the seed stock is as free as possible from this disease. Screening for this disease has relied primarily on visual symptoms and a bioassay on tomato seedlings. However, since the potato spindle tuber viroid exists in many strains that result in mild to severe symptoms or no symptoms, the tomato test is often unable to detect the presence of the viroid. Presence of mild strains can often only be detect by challenging the tomato plant with a known severe strain and checking for cross protection. This adds extra time to the assay. My own experience with the disease has revealed enough variation in the growth of the tomato to cause some confusion in diagnosis. The spindle tuber viroid consists only of single stranded ribonucleic acid (RNA). Thus, the viroid can be assayed for by physical-chemical means. Since the viroid has a definite size and electrical charge, it can be separated and identified by electrophoresis. Several techniques have been described for such an assay (1,2,3). I have developed a procedure based on these reports which will fit in well with our seed research program. Procedure One-half gram of apical stem tissue is excised from infected and non-infected plants. The tissue is immediately placed into liquid nitrogen to freeze the tissue and the tissue is stored at -20C until assayed. The frozen tissue is ground to a fine powder and placed into a pre-chilled 15 ml centrifuge tube. 1.5 ml of extraction buffer and 2 ml of water saturated phenol containing 0.1% 8-hydroxyquinoline are added to the tissue powder and the mixture is allowed to thaw. The thawed mixture is then mixed vigorously and allowed to shake for one hour on ice. The leaf residue is removed by centrifugation and the clear supernatant removed and transferred into another test tube. Three volumes of cold (-20C) 96% ethanol are added to the supernatant and the tube is placed in a freezer for one hour. The plant nucleic acids, and PSTV if present, are precipitated during this time. The precipitate is collected by centrifugation, washed with 96% ethanol and dried under vacuum for 15 minutes. The pellet is redissolved in 200 ul of 0.5M sucrose containing 0.05% bromophenol blu and used immediately for electrophoresis or stored at -20C. Electrophoresis is carried out by the method of Morris and Smith. Results Figure 1 shows a diagram of a typical separation of PSTV from infected plants. The technique is sensitive enough to allow assay of several plants at once. This allows the assay of many more plants at once than was possible with the tomato test. When batch testing is performed and a positive test given, then the individual plants can then be tested and removed. Results with tuber tissue have not been successful in my hands as of this time. FIGURE 1 R.W. Chase & R.B. Kitchen, Dept. of Crop & Soil Sciences MINI-TILL POTATOES Lynn Sampson Bay County SCS Warren Schauer Bay County Extension Ag Agent Procedure Wind erosion on potatoes and sugarbeets are a common occurrence in the Bay County area. In an effort to evaluate the effect of crop residues and tillage on establishing a stand of potatoes, plots were established at the farm of Henry Mulders in Munger. On August 25, 1980 a field previously planted to potatoes was plowed and planted to four cover crops with 3 replications as follows: Cover Crop Wheeler rye Mariner oats Red proso millet Hay-R-Graze sorghum- sudan hybrid Seeding Rate Oct. 1980 Growth 80 lbs/A 64 lbs/A 25 lbs/A 30 lbs/A Excellent cover 7-8 inches vigorous growth no stand - poor seed Sparse stand Sparse stand 6 inches 6-7 inches * * * Both were completely dead by mid-October because of frost The oats, millet and sorghum-sudan hybrid were selected because they would freeze during the winter and therefore require no tillage or chemicals before planting. It was determined that there was insufficient warm weather in the fall of 1980 to obtain a satisfactory stand of millet or a sorghum-sudan hybrid. On April 13 the rye was sprayed with paraquat at 1 qt/A plus X77 at 8 ounces/100 gallons water. The area was divided with one half being plowed before planting. The remaining area received no tillage and Katahdins were planted at 8 X 34 inches with a modified two-row Lockwood planter on April 27, 1981. Soil temperature at 8 inches was 44° in the soil seeded to rye and 49° in the tilled area. Fertilizer was applied in the planter at 900 lbs/A 9-18-18 + 2% Mg. 1/2% Mn. Temik was applied at 20 lbs/A. After planting, one half of the area was dragged off while the remaining area received no tillage until hilling. Results At planting difficulty was experienced in obtaining good soil cover over the seed piece in the rye cropped area. The covering soil bunched and did not give good uniform coverage. The planting and coverage in the millet, oats and sorghum-sudan plots was very adequate because of the sparse and non-active vegetative residue. At harvest there was no problem with the rye residue. Yield checks were taken from the rye and millet plots within the areas which were dragged and not dragged after planting. The yield results are shown in Table 1. Yields from the dragged off rye plots were greater than when not dragged and this is likely due to the improved soil cover over the planted seed piece. Yield checks from the area which was plowed and prepared conventionally were not taken because of a different planter and planting date. The results of this initial test showed that potatoes can be planted and grown on this soil type without primary tillage with satisfactory yields. The project is being continued and winter cover crops of oats, spring barley and rye were planted on September 14, 1981. Table 1. The yield, size distribution, and specific gravity of Katahdin potatoes grown with minimum tillage at planting (Mulders 1981) NOT DRAGGED-OFF NOT DRAGGED-OFF NOT DRAGGED-OFF NOT DRAGGED-OFFNOT DRAGGED-OFF NOT DRAGGED-OFF NOT DRAGGED-OFF Cover Crop Rye Millet Total Yield (cwt/A) 390 440 DRAGGED-OFFDRAGGED-OFF Rye Millet 420 379 US No. 1 Yield (cwt/A) 367 409 381 351 2 - Percent 3 1/4" 55.2 64.5 Percent Percent Over 3 1/4" Under 2" 38.8 28.4 6.0 7.1 S.G. 1.066 1.068 DRAGGED-OFF DRAGGED-OFF DRAGGED-OFFDRAGGED-OFFDRAGGED-OFF 69.5 65.8 21.2 26.7 9.3 7.5 1.062 1.065 THE EFFECT OF STORAGE TEMPERATURE DELAYED PLANTINGS OF CUT SEED AND SEED TREATMENT ON STAND AND YIELD OF POTATOES Dept. of Botany & Plant Pathology H. S. Potter Environmental studies with cut potato seed were continued at the Montcalm Experimental Farm during 1981. These studies have attempted to evaluate the effect of storage temperature, delayed planting of cut seed and seed treatment on stand and yield. Certified Monona seed was cut and treated at 3 time intervals before planting, 14 days (April 26), 2 days (May 6), and 0 days (May 8). Treatments included (1) sodium hypochlorite (clorox) 500 ppm, (2) streptomycin sulfate + captan 10+10% dust 1 Ib/CWT of seed and (3) plain water. The sodium hypochlorite and water treatments were applied as a 2 minute dip. Streptomycin + captan dust was applied by thoroughly agitating the seed and chemical in a closed plastic bag until cut surface was thoroughly covered. For two weeks prior to planting all whole or cut seed used in the tests was stored at either 40-45°F or at 65-70°F with a relative humidity of 90%. Planting was done by hand (May 8) in 34 inch rows with seed pieces spaced 9 inches apart. Treatments were randomized and replicated three times in a single block planting. Plots consisted of a single 25 foot row. Temiks was applied at planting for early insect control and supplemented with foliar applications of Thiodan as needed. Fungicide sprays either Dithane M-45 or Bravo 500 were applied at regular intervals. Irrigation was used when neces­ sary to maintain vigorous growth. A stand count was taken at 4 and 6 weeks after planting. The plots were harvested on October 6. Results indicate that the longer the time interval between cutting seed and planting the poorer the stand. Seed stored at 40-45°F is likely to produce a poorer stand than seed stored at 65-70°F. The greatest difference in the effect of temperature on stand is found with cut seed stored at the longest time interval. And inversely the least effect of temperature on stand occurs where seed is cut and planted the same day. Chemical seed treatment appears to benefit stand particularly when cut seed is stored for longer periods before planting. This is more apt to be true when stored at 40-45°F than at 65-70°F. In this and in previous tests there wasn't always a good correlation between stand and yields. In some instances a moderate stand would result in a higher yield than a very good stand. 1981 RESULTS POTATO CUT SEED TRIALS TREATMENT AND RATE METHOD OF APPLICATION 14 0 % STAND YIELD CWT/A US=1 YIELD CWT/A B GRADE BEFORE PLANTING-DAYS TIME SEED CUT TIME SEED CUT BEFORE PLANTING-DAYS 2 TIME SEED CUT BEFORE PLANTING-DAYS STORAGE TEMPERATURE 40-45°F STORAGE TEMPERATURE 40-45°F STORAGE TEMPERATURE 40-45°F STORAGE TEMPERATURE 40-45°F STORAGE TEMPERATURE 40-45°F STORAGE TEMPERATURE 40-45°F STORAGE TEMPERATURE 40-45°F STORAGE TEMPERATURE 40-45°F empty table cellempty table cell SODIUM HYPOCHLORITE 500PPM " " " " " " STREPTOMYCIN SULFATE+CAPTAN 10+10D 1 L5/CWT OF SEED WATER ONLY " " " " " " " " " " NO TREATMENT " " LSD .05 LSD .01 " DIP " DUST " " DIP " " empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell X empty table cellempty table cellX 354.0 empty table cell90.0 360.8 366.3 empty table cellempty table cell74.0 338.6 92.5 66.2 X X X X empty table cell X empty table cellempty table cellX empty table cell X empty table cellempty table cellX empty table cell88.8 364.5 94.5 355.9 empty table cellempty table cell63.0 293.7 320.2 79.0 327.6 empty table cellempty table cell60.0 315.8 338.6 88.8 346.0 empty table cell62.7 empty table cell77.5 empty table cell X empty table cellempty table cellX empty table cellempty table cellempty table cell 13.0 empty table cellempty table cellempty table cell19.6 23.0 34.2 21.5 12.3 13.0 9.2 21.5 12.4 17.9 16.0 18.7 14.2 9.2 16.5 4.3 6.5 STORAGE TEMPERATURE 65-70°F STORAGE TEMPERATURE 65-70°F STORAGE TEMPERATURE 65-70°F empty table cellempty table cell STORAGE TEMPERATURE 65-70°F STORAGE TEMPERATURE 65-70°F STORAGE TEMPERATURE 65-70°F STORAGE TEMPERATURE 65-70°F STORAGE TEMPERATURE 65-70°F SODIUM HYPOCHLORITE 500PPM " " " " " " STREPTOMYCIN SULFATE+CAPTAN 10+10 DUST " 1 LB/CWT OF SEED " " " " " " WATER ONLY NO TREATMENT " " " " " " LSD .05 .01 LSD COMBINED TABLES LSD .05 LSD .01 DIP " DUST " " " DIP " empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell X empty table cell X empty table cellempty table cellX 82.8 366.3 empty table cell88.2 371.3 97.3 370.4 empty table cellempty table cell87.0 349.8 X X X empty table cell X empty table cellempty table cellX empty table cell X empty table cellempty table cellX empty table cell95.3 380.1 98.7 399.5 empty table cellempty table cell79.2 307.8 empty table cell87.3 322.9 82.0 329.4 empty table cellempty table cell76.5 324.5 empty table cell92.8 341.7 94.7 353.0 empty table cell X empty table cellempty table cellX empty table cellempty table cellempty table cell 7.5 empty table cellempty table cellempty table cell11.3 empty table cellempty table cellempty table cell 27.5 41.7 12.3 13.5 14.2 23.4 18.5 9.2 18.5 24.6 20.3 15.4 16.0 15.4 4.6 6.9 empty table cell 10.2 empty table cellempty table cellempty table cell15.4 25.2 37.9 4.4 6.7 WEED CONTROL IN POTATOES William Meggitt, Richard Chase, Gary Powell and Richard Kitchen Department of Crop and Soil Sciences Herbicide treatments for control of barnyard grass and annual broadleaved weeds are shown in Table 1. All soil applied treatments, Eptam (PPI), Lasso, Dual and Prowl (Pre), provided excellent control of barnyard grass. Lexone, Sencor and Lorox applied as a delayed preemergence treatment (after weeds had emerged, but before potatoes emerged) gave complete control of broadleaved weeds. Combinations of the grass herbicides (Lasso, Dual, Prowl) plus Lexone or Sencor applied as a preemergence treatment also provided excellent grass and broadleaved weed control. Plots that were weed-free at the time of early hilling (weeds covered by hilling) and then sprayed preemergence also remained weed-free throughout the growing season. In general if treatments are applied early and no further tillage is practiced, excellent weed control throughout the season is possible. Another phase of the study was to evaluate new chemicals for postemergence control of annual grass. Several treatments shown in Table 1, were applied to barnyard grass 2-4 inches tall. Broadleaved weeds had been controlled with Lexone or Sencor applied delayed preemergence. Excellent grass control 95-98% was obtained from all chemicals tested with little or no visible injury to potatoes. Oil concentrate at 1 quart per acre was added to all postemergence treatments to increase penetration of weed foliage. Potato yields shown in Table 1, indicated few significant reductions. Two exceptions, were combinations that included Prowl applied preplant incorporated or after early hilling and Dual at high rates. In these cases the yields were significantly lower than highest yields in test and not lower than the overall treatments average. Yields were somewhat variable. Data for the potato vine killing study is shown in Table 2. In this study, an evaluation was made to determine if more effective desiccation or burn-down could be obtained if the vines were pushed over to give more direct contact with the potato stems. Two methods were used to push down the vines directly in front of the spray boom. The results of this study did not show any advantage for pushing the vines down. At the time of application, the potato vines were beginning to mature, and good to excellent "kill” was obtained with all treat­ ments. Diquat, which obtained label clearance in 1981 for potato vine desiccation, provided the most effective "kill". TABLE 1: Preplant Incorporated, Preemergence and Postemergence Weed Control Evaluations in Potatoes Montcalm Co., Michigan 1981. PPI Pre D. Pre D. Pre Rate lbs/A Treatment 4 + 1/2 2 + 1 + 1/2 D. Pre May 8, 1981 Russett Burbanks 34” 102” x 50’ 3 Date Planted: Variety: Row Spacing: Plot Size: No. of Replications: Incorporation Equipment: Springtooth Drag x 2 Weeds Present: Barnyard grass, Pigweed, Lambsquarters Trt. No. empty table cell PPI D. Pre Eptam + Lexone DF Eptam + Prowl + Lexone DF Pre Prowl + Lexone DF Prowl + Lorox 4L Dual + Lexone DF Dual + Lexone DF Dual + Lorox 4L Dual + Lexone DF Surflan + Lexone DF Pre 1. 2. empty table cell 3. 4. 5. 6. 7. 8. 9. empty table cell 10. Prowl + Lexone DF 11. Dual + Lexone 12. Lasso + Lexone empty table cell 13. Lasso + Sencor Sprayule 14. Dual + Sencor Sprayule 15. Prowl + Sencor Sprayule 16. Sencor + Poast + OC 17. Sencor 18. Sencor 19. Lexone DF + CGA 82725 + OC 20. Lexone DF + CGA 82725 + OC 21. Lexone DF + ICI PP 009 + OC 22. Lexone DF + Nissan 96683 + OC 1 + 1/2 1 + 1 3.6 + 1/2 4.8 + 1/2 3.6 + 1 2.4 + 1/2 3/4 + 1/2 1 + 1/2 2 + 1/2 2 + 1/2 Early Hill & Spray 2 + 1/2 2 + 1/2 1 + 1/2 1/2 + 1/8 + 1 qt 1/2 1/2 1/2 + 1/4 + 1 qt 1/2 + 1/2+1 qt 1/2 + 1/4+1 qt 1/2 + 1/4+1 qt empty table cell Early Hill & Spray empty table cell LSD Pre Date Treated: PPI: - 5/8/81 Pre: - 5/8/81 Delayed Pre: - 5/27/81 Post: - 6/17/81 6/23/81 Loamy Sand Date Rated: Soil Texture: Organic Matter: 2% PW BG D. PrePPI LQ D. Pre PPI PPI Injury D. Pre PPI D. PrePPI Yield cwt/A D. Pre D. Pre 9.0 9.2 9.5 9.8 10.0 10.0 10.0 10.0 8.5 10.0 10.0 D. Pre Pre 10.0 10.0 10.0 10.0 10.0 10.0 10.0 Pre Pre Pre 8.8 9.8 8.3 10.0 10.0 10.0 9.2 9.8 9.0 9.8 8.8 8.3 9.2 9.8 9.5 9.7 10.0 10.0 9.8 10.0 10.0 10.0 10.0 10.0 10.0 10.0 Pre 313 289 0.0 1.3 D. PrePre 339 325 315 278 299 300 330 Pre D. Pre Pre 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.0 10.0 D. Pre Pre 10.0 10.0 10.0 10.0 10.0 10.0 10.0 Pre 0.0 10.0 0.0 10.0 0.0 10.0 Early Hill & Spray 10.0 0.0 9.7 0.0 0.0 10.0 10.0 0.0 10.0 0.0 10.0 0.0 10.0 0.0 10.0 0.0 10.0 0.0 10.0 1.0 341 326 334 Early Hill & Spray 347 314 274 312 329 328 306 314 306 312 Early Hill & Spray Early Hill & Spray Early Hill & Spray Rating based on a 1-10 scale; 0 - no injury, 10 - complete kill empty table cell empty table cell empty table cell empty table cell 43 TABLE 2: Potato Vine Killing, Montcalm County, Michigan, 1981 Variety: Russett Burbank Date Treated: 9/3/81 Row Spacing: 34" Date Rated: 9/8/81 Spray Pressure: 40 PSI Plot Size: 102" x 50' Spray Volume: 46 GPA No. of Replications: 3 *Wood Board and Steel Bar were draged behind spray tractor, but directly in front of spray boom to hold potato vines down. Trt. No. Treatment Rate lbs/A Average 3 Reps % Kill 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. Diquat Diquat Diquat Diquat Diquat Diquat Diquat + Ammonium Sulfate Diquat + Copper Sulfate Dow General + Ammonium Sulfate Dow General + Copper Sulfate Dow General Dow General Dow General Dow General Dow General Dow General 1 pt (1" x 2" Steel Bar) 1 pt (2” x 4" Wood Board) 1 pt 1 1/2 pt (1” x 2" Steel Bar) 1 1/2 pt (2” x 4" Wood Board) 1 1/2 pt 1 pt + 5 lb 1 pt + 8 lb 2 pt + 5 lb 2 pt + 8 lb 2 pt (1" x 2" Steel Bar) 2 pt (2" x 4" Wood Board) 2 pt 3 pt (1” x 2" Steel Bar) 3 pt (2" x 4" Wood Board) 3 Pt 93 90 93 85 93 95 88 82 90 85 80 87 85 87 92 87 THE INFLUENCE OF NEMATICIDES ON PRATYLENCHUS PENETRANS AND TUBER YIELDS OF 'ATLANTIC' POTATOES G.W. Bird and J. Davenport Department of Entomology Temik 15G (3.0 lb. a.i./A) and Mocap 10G (1.5, 3.0, 6.0 and 9.0 lbs. a.i./A) were evaluated for the control of Pratylenchus penetrans associ­ ated with the production of Atlantic potatoes. A complete randomized block design was used with five replications. Seed pieces were planted May 14, 1981 at the Montcalm Potato Research Farm. Each consisted of four rows 34 inches apart, 50 feet long and seed pieces at a 10 inch spacing. All nematicides were applied the day of planting. Mocap treatments were broadcast and incorporated and the Temik 15G was banded beside the seed furrow. The experiment received the same rate of fertilizer, foliar insecticides and irrigation as the general test plots on the Montcalm farm. Soil samples were analyzed for nematodes using the centrifugation-floatation technique and the roots were processed using the shaker extraction technique. P. penetrans, the root-lesion nematode, densities at planting averaged 17 per 100cm3 of soil were not significantly different (P=0.05) between treatments (Table 1). They were sampled on 5/14, 7/9, 8/10, and 9/11. On July 9 the root samples indicated no significant differences in nematode densities, however the soil analysis indicated that generally the check had higher populations than the nematicide treatments. On August 10, based on the results from the root extractions, the check had the highest population densities of P. penetrans. The nematicides had lower densities with some differences in control between the nematicide treatments. On September 11 the use of Temik 15G resulted in signifi­ cantly greater control of P. penetrans than all other treatments. Total tuber production was lowest in the check and Mocap 10G at 1.5 lb. a.i./A treatments and significantly higher in all other treatments (Table 2). There were no differences in ’b’ size tuber yields. The use of Temik 15G resulted in a significantly higher amount of oversized tubers than the check, but the specific gravity was lower than all other treatments. Table 1. The Influence of Nematicides on Pratylenchus penetrans Associated with Atlantic Potatoes Nematicide a.i./A Pratylenchus penetrans Population Density May 14 100cm3 soil Pratylenchus penetrans Population Density July 9 1.0g root Pratylenchus penetrans Population Density July 9 100cm3 soil Pratylenchus penetrans Population Density August 10 1.0g root Pratylenchus penetrans Population Density August 100cm3 soil Pratylenchus penetrans Population Density Sept. 11 100cm3 soil Check Temik 15G2 Mocap 10G3 Mocap 10G Mocap 10G Mocap 10G empty table cell 16.0a1 3.0 1.5 3.0 6.0 9.0 18.4a 16.8a 14.4a 20.8a 17.6a 5.6a 1.6a 4.8a 2.8a 4.0a 0.4a 7.2b 1.6a 2.4ab 0.2a 2.0ab 0.8a 76.4c 0.4a 9.6ab 0.4a 16.8b 8.0ab 1.6a 0.0a 1.6a 1.6a 3.2a 0.8a 69.6b 4.0a 64.8b 52.8b 100.0b 80.8b 1Column means followed by the same letter are not significantly different according to the Student-Newman-Keuls Multiple Range Test. 2 Banded beside the seed furrow 3 Broadcast and incorporated with a disk Table 2. Tuber Yields of Atlantic Potatoes as Affected by Nematicides Nematicide a.i./A Total Specific Tuber Yields (cwt/A) Tuber Yields (cwt/A) Small Oversized Gravity Check Temik 15G2 Mocap 10G3 Mocap 10G Mocap 10G Mocap 10G empty table cell 3.0 1.5 3.0 6.0 9.0 330.4a1 369.5b 326.2a 378.1b 397.2b 393.2b 45.2a 81.2b 60.1ab 60.6ab 67.6ab 68.9ab 13.2a 13.2a 11.8a 14.0a 13.4a 14.6a 1.093b 1.085a 1.091b 1.092b 1.090b 1.091b 1Column means followed by the same letters are not significantly different (P=0.05) according to the Student-Newman-Keuls Multiple Range Test. 2Banded beside the seed furrow 3Broadcast and incorporated with a disk EFFECT OF PRE-PLANT SOIL TREATMENTSON THE CONTROL OF POTATO SCAB H.S. Potter and R.L. Ledebuhr Departments of Botany & Plant Pathology & Agricultural Engineering In 1981 additional tests were conducted at the Michigan State University Soils Farm to further evaluate the nitrate inhibitor Dwell and the fungicide Terraclor for control of potato scab. The test site had a fine sandy loam soil with a pH of 7.2. It had been used to grow potatoes for the past five years and the soil was known to be heavily infested with the scab pathogen. All fertilizer requirements except nitrogen were plowed down. Nitrogen as urea was banded on the furrow at planting along with Dwell and Terraclor. Up until now this had been done with a hand sprayer followed by rototilling to get a uniform mix with the soil. In 1981 a new type of applicator was used which sprays and incorporates the chemical in one operation. The appli­ cator consists of a rectangular frame within which are mounted two back swepted shanks that can extend into the soil to a depth of 7 inches. Wide angle flat fan nozzles are mounted on the shanks. On one, the nozzle is located so as to spray at a depth of 3 1/2 inches, on the other at a depth of 7 inches. Delta wing shrouds cover the nozzles and allow the spray to be distributed across a 12 inch band. A series of vibrating type tines set at different depths are mounted behind the shanks. These vertically mix the soil and distribute the chemical within the soil profile. A conventional spray pump system delivers the chemicals to the nozzles. The entire unit is mounted on a 3 point hitch tool bar. Application of treatment with this equipment were made prior to planting. However, it would be desirable to use the applicator in conjunc­ tion with the planting operation. This probably could be done by extending the tongue of the planter to allow room for the equipment mounted on the tool bar. When using the applicator this past summer the tractor was operated at 3 to 4 m.p.h. At these speeds we got excellent distribution which was determined by using florescent tracers. Certified Sebago seed was used in the 1981 tests. This was cut and planted on May 22 in single row plots 50 feet long. The row width was 32 inches with seed pieces spaced 9 inches apart. A single guard row separated each plot. Treatments were arranged in a single block planting, randomized and replicated 5 times. Plots were mechanically weeded and sprayed weekly for disease control. Temik was not used in the furrow because of the pos­ sibility that it might interfere with the scab treatments. Foliar insecti­ cides were substituted for Temik as needed. The results from these tests show a highly significant increase in the percent and yield of marketable tubers with the Dwell Terraclor treatment as compared with the checks. Terraclor alone also significantly increased percent and yield of marketable tubers but Dwell alone did not although the data were trending in that direction. In past tests Dwell alone consistently resulted in significant benefits equal to that of Terraclor alone. The results of this test further indicates that the experimental appli­ cator used for the first time in 1981 may be a practical substitute for tedious time consuming application methods previously used. Further modifi­ cations of this equipment are planned which we hope will improve its operating capabilities. EFFECT OF PRE-PLANT SOIL TREATMENTS ON THE CONTROL OF SCAB Treatment1 Rate/A US #1 Average Yield CWT/AHarvested CWT/AHarvested Average Yield Average Yield CWT/A B Grade US#1 Marketable2 Average Yield CWT/AMarketable2 B Grade Ave. % Marketable Tubers Dwell 2EC .5 lb ai (1 (qt) Terraclor 2EC 12.5 gal Dwell 2EC + .5 lb ai (1 qt) Terraclor 2EC + 12.5 gal Check — — — 169.0 165.1 169.3 159.2 LDS .05 .01 LDS empty table cell empty table cell NS empty table cell 18.0 16.6 20.6 14.7 4.2 NS 128.6 133.8 154.0 101.8 30.0 42.1 13.7 13.7 17.6 9.5 5.2 7.5 76.2 80.9* 91.0** 63.6 14.5 20.3 1 150 lbs of N in form of urea applied in a band on all plots. 2 Potato tubers with not mroe than 2% scab. 3 * = significantly different from check at 5% level. " " " " " 1% level. ** = CONTROLLED DROPLET SPRAYING FOR CONTROL OF EARLY AND LATE BLIGHT OF POTATOES H. Spencer Potter Department of Botany & Plant Pathology Controlled droplet and conventional nozzle methods of spraying were com­ pared on potatoes for control of late blight (Phytophthora infestans) and early blight (Alternaria solani) using Bravo 500 at the recommended rate (2 pt/A) and at the half rate (1 pt/A). Tests were conducted at the Michigan State University Muck Research Farm with the variety Russet Burbank. The experimental design consisted of two parallel block plantings 200 feet long and 50 feet wide. Treatments were ran­ domized and replicated twice in each block. The plots were 50 feet in length and 12 feet in width. They were arranged along both sides of the blocks so that sprays could be applied without mechanically damaging the plants. A 25 foot wide unsprayed strip running down the center of each block served as a check. The spray equipment used was an experimental tractor-mounted unit sup­ plied by the Spray-Rite Company. It combined two types of spraying devices. On one side was a conventional brush boom with low pressure flat fan wide angle (110°) nozzles (Spraying Systems #11003LP). On the other a boom on which were mounted 5 micromax rotary atomizers (Micron) spaced 2 ft. 7 in. apart. The atomizers were electrically powered with a belt drive and two pully combinations, one for high speed operation (5000 RPM) and one for low speed (2000 RPM). Changing the rotating speed regulates the droplet size. In this test the rotating speed was 2000 RPM which produced droplet sizes ranging between 200 and 250 microns. Both spraying systems were operated at 20 psi. The output for the con­ ventional nozzles was 25 gal/A and for the controlled droplet atomizer (C.D.) 5 gal/A. Fungicide applications were applied weekly from June 29 to September 22 (13 applications). Plots were inoculated at the end of July and again in mid August with the late blight fungus. The disease, however, did not begin to develop until early September when the weather turned cool and wet. By the middle of the month when final disease readings were taken, both late blight and early blight infections were moderate to severe in the unsprayed control. Shortly after that the vines were severely damaged by frost and later by flooding. Harvesting took place during the first week in October. Results shown in the table below indicate that method of application had no significant effect on the incidence of early and late blight infection nor on yield of US#1 potatoes. The rate of application, likewise, had no significant effect on disease incidence, but at the half rate, yields were significantly less than at the full rate. Based on these and other data it is apparent that controlled droplet applicators using reduced amounts of water may be substituted for conventional spray equipment. However, at this time it would be unadvisable to apply less than the recommended rate of a chemical when using controlled droplet atomizers or any other type of spray dispensing equipment. EFFECT OF CONTROLLED DROPLET AND CONVENTIONAL SPRAYING METHODS ON DISEASE CONTROL AND YIELD IN POTATOES Atomizer Type Rate1 Disease Index2 Late Blight Disease Index2 Early Blight Yield CWT/A US #1 Yield CWT/A B Grade Nozzle Nozzle C.D. Atomizer C.D. Atomizer Control LSD .05 Full Half Full Half empty table cell empty table cell 1.8 2.8 1.9 2.4 5.3 1.5 1.7 2.6 1.6 1.8 3.8 1.2 262.9 223.3 264.5 224.9 166.3 57.0 63.4 58.6 64.9 63.4 35.0 NS 1Bravo 500 Full rate 2 pts., half rate 1 pt. (Formulation) 2Disease Index - 0 = No disease - 10 = 100% defoliation WIREWORM AND WHITE GRUB CONTROL IN POTATOES Arthur L. Wells Department of Entomology Wireworms and white grubs (Phyllophaga sp) continue to be the most serious soil insects on first year potatoes after breaking up fallow sod- born fields. When the normal food source of these insects which have built up over successive years is destroyed by plowing and cultivation the larvae will shift their feeding to the roots of the newly planted crops. Complete destruction of the yield or quality of the crop may result if an effective control program is not available. The loss of chlordane and other chlorinated hydrocarbon insecticides led immediately to the search for substitute compounds such as the organo­ phosphates. Certain of these have shown to be effective and are now labeled for use against wireworms on most crops including potatoes, however no materials have been labeled for white grubs on potatoes. Since the use of systemic insecticides which are effective on certain soil organisms has been accepted so extensively by the growers the possible effectiveness of a combination of broadcast soil insecticide and the in-row application of the systemics is being studied. Previous research reports have indicated these combinations have been additive in their effectiveness on wireworms and possibly white grubs. Low resident populations of white grubs in the research plots has not provided adequate data to support this registration or use pattern. One of the biggest deterrants to this research objective is the locating of grub infested fields which would be available for this type of work. The field should be in a potato growing area so commercial production practices could be followed. Another factor is the control process estimating the resident popula­ tion of the soil insects and determining their damage potential to the potato crop. The use of baits to attract the insect larvae have been studied in other areas but have not been evaluated in Michigan. 1981 Research A field was located near Rockford in Kent County to evaluate the sampling of soil insect larvae and their control with the use of combination insecticide treatments. The field which consisted of about 14 A. had been fallow for several years and was to be planted to potatoes. Baits were prepared by cutting squares of cheese cloth and placing a small handful of corn meal, rolled oats, shelled corn and 1/2 potato on each and tieing into a sack. On April 3 twenty of these bait stations were placed randomly around the field at a 6 inch depth and marked with a white stake. This placed them in the root zone of the grass and weed cover and would attract any wireworms or white grubs which may come up and feed in the area. Three weeks later, on April 24, the bait stations were examined for insects. The bait bags were carefully removed from the soil and placed in a 1/4 inch wire sieve and examined for insects. A one square foot sample of sod around the bait was also removed and sifted for insects. Another sample immediately below the root zone was also examined and sifted for insects which might still be moving up into the root zone for feeding. The insect populations from the samples are given in Table 1. The field was plowed in early May prior to planting potatoes. Arrange­ ments were made with the grower to apply Dyfonate 4 A at 1 gallon per acre on part of the field leaving a strip one spray boom wide untreated as a check. The part of the field on the other side of the creek was treated with Mocap 6 E at 2/3 gallon per acre and the rest to Dyfonate separated from the Mocap with an untreated strip. The materials were applied with a herbicide as a tank mix. The field was disced immediately after to incorporate the pesticides prior to planting. The field was planted in mid May using Sebago seed and applying Temik 15 at 20 lb/A in the fertilizer band. Normal cultural practices were then followed until harvest. On October 5, 20 row-foot samples were selected at random in each of the treated areas. The hills were dug and the tubers were bagged and identified for future examination. All insects seen in the bottom of the hills or on the exposed soil were saved, identified and the numbers are presented in Table 2. The tubers were taken to the Montcalm Experimental Farm and allowed to dry for damage evaluation. The tubers were graded by size into B’s (to 1-7/8”), A’s (1-7/8” - 3-1/4”) and oversize (3-1/4” +). Each of these size grades were further rated according to wireworm and white grub damage. A damage rating of 1-indicated no insect feeding damage, 2-minor wireworm feeding, 3-extensive wireworm damage and white grub damage. The tubers in each of these size and damage grades were counted and weighed to determine the yield and effectiveness of the soil insecticide program. The data are presented in Table 3. Results. The soil sampling was a more effective means of estimating the insect populations than were the baits alone, however it is possible the insects were attracted up into the root zone around the baits. The fermen­ tation of the bait attracted more wireworms than white grubs. Over 75% of the insects were found in the root zone with the rest equally divided between the bait and the sub-root zone area. The overall sampling indicated an average of 3.3 white grubs and 3.5 wireworms per square foot of soil. This population is considered as having an extremely damaging potential to potatoes. The free insects collected at harvest indicate a shift of the small spring white grubs to the later instar forms with no reproduction of young in the treated plots. The wireworm population remained high in the untreated area in the south field. Both soil materials were very effective in controlling wireworms when compared with the tuber damage in the areas treated only with Temik. The combination treatments also greatly reduced the amount of grub damage in the tubers. There appeared to be very little if any difference in yield or sizes of the tubers in any of the plots. Table 1. Wireworm and white grub populations near the bait stations South Field White Grubs Large White Grubs Small Wireworms Cutworms 1 Bait 1 Root Zone 1 Sub-Root Zone 2 Bait 2 Root Zone 2 Sub-Root Zone 3 Bait 3 Root Zone 3 Sub-Root Zone 4 Bait 4 Root Zone 4 Sub-Root Zone 5 Bait 5 Root Zone 5 Sub-Root Zone 6 Bait 6 Root Zone 6 Sub-Root Zone 7 Bait 7 Root Zone 7 Sub-Root Zone 8 Bait 8 Root Zone 8 Sub-Root Zone 9 Bait 9 Root Zone 9 Sub-Root Zone 10 Bait 10 Root Zone 10 Sub-Root Zone 0 4 0 0 3 0 Ripped up by a fox or skunk Ripped up by a fox or skunk Ripped up by a fox or skunk 4 1 5 2 0 2 4 0 1 0 1 1 0 0 4 0 0 1 1 0 0 0 0 0 0 0 0 0 0 6 2 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 7 0 0 1 0 1 0 3 9 0 0 3 6 0 0 0 0 0 0 0 7 + 1 Ad 3 + 1 Ad 1 + 1 Ad Samples 1-10 Totals Bait 1 0 4 0 Samples 1-10 Totals Root Zone Sub-Root Zone Samples 1-10 Totals Totals 17 6 24 15 4 19 33 + 3 Ad 6 43 3 0 0 0 Ripped up by a fox or skunk 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 - 0 0 0 0 0 0 0 0 0 0 2 0 2 Table 1--Continued North Field 11 Bait 11 Root Zone 11 Sub-Root Zone 12 Bait 12 Root Zone 12 Sub-Root Zone 13 Bait 13 Root Zone 13 Sub-Root Zone 14 Bait 14 Root Zone 14 Sub-Root Zone 15 Bait 15 Root Zone 15 Sub-Root Zone 16 Bait 16 Root Zone 16 Sub-Root Zone 17 Bait 17 Root Zone 17 Sub-Root Zone 18 Bait 18 Root Zone 18 Sub-Root Zone 19 Bait 19 Root Zone 19 Sub-Root Zone 20 Bait 20 Root Zone 20 Sub-Root Zone Samples 11-20 Totals Bait White Grubs Large White Grubs Small Wireworms Cutworms 0 0 0 0 3 2 0 2 1 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 2 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 1 1 5 0 8 3 0 0 0 0 0 1 0 0 0 0 0 0 0 1 + 1 Ad 0 0 0 0 0 1 0 0 0 3 1 1 0 11 + 1 Ad 0 Root Zone Samples 11-20 Totals Sub-Root Zone Samples 11-20 Totals Totals 9 3 13 9 1 10 12 1 24 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 Small White Grubs White Grubs Large White Grubs Adult Table 2. Soil insects found while sampling the potato plots Location and Treatment South Field Dyfonate 4E South Field Untreated North Field Dyfonate 4E North Field Mocap 6E North Field Untreated Wireworms 1 4 10 1 33 0 0 0 3 1 0 3 1 0 1 2 1 1 1 1 1 0 1 1 3 False Wireworms Wooly Bears 0 0 1 1 1 Table 3. Yields, size grades and tuber damage from the soil insect study Percent by Damage Rating Percent by Size Percent by Damage Rating empty table cell Percent by Damage Rating Percent by Size Percent by Damage Rating 1 2 3 Grub CWT/A B’s A's Percent by Size 3-1/4 + South Dyfonate 4E Untreated South North Dyfonate 4E Mocap 6E North North Untreated 255 262 283 277 280 7 7 5 4 6 76 63 61 60 64 17 30 34 36 30 91.9 53.2 93.6 93.1 70.2 4.5 19.1 4.4 0.7 14.0 0.4 18.5 -- 0.3 1.2 3.2 9.2 2.0 5.9 14.6 FOLIAR INSECT CONTROL ON POTATOES Arthur L. Wells Department of Entomology Sixteen insecticide treatments including foliar and soil systemic materials were evaluated against the foliar insect complex on potatoes in 1981. The plots consisted of paired 50 foot rows randomized in three replications using Russet Burbank variety of seed. The rows were left open during the planting operation on May 13 so the band applications of the systemics could be made prior to covering. Space for one row was left between each plot to allow access to the plots for spraying and sampling. Recommended fertilizer, herbicide and fungicide programs were followed during the study. A CO2 sprayer delivering 70 gallons per acre was used to apply the foliar insecticides. Applications were made on June 30, July 7 and 24 and August 10. The foliar insects were sampled with an insect net on July 7, 24, August 3 and 19 prior to the insecticide application on the corresponding days. The insect data are presented in Table 1 and 2. A vine killer was applied in mid September and the plots were harvested on October 8. The potato yields, size distribution, and specific gravity from the plots are presented in Table 3. Results The principle insects present in the samples were tarnished plant bugs and Colorado potato beetles. A few potato leafhoppers and other insects occurred early in the plots but they are not included in the tables. The potato beetle was certainly the predominant foliar feeder and caused extensive foliage loss to the untreated plots. All of the foliar insecticides in the study with the exception of Monitor and Lorsban were synthetic pyrethroid compounds and have shown effectiveness against the beetles in other studies. They again, as a group, provided as good control as Monitor even at extremely low rates of application. Lorsban was shown to be very effective also. The BASF material and Temik gave season long control of the beetles, however the Temik provided better yield possibly due to the nematicidal activity. All of the foliars gave higher yields than the untreated plots which indicate the value of an effective control program for this insect. There appeared to be very little differences in the size grade or the specific gravity of the tubers from any of the plots. Lb ai /A Foliar Applications Table 1. Control of tarnished plant bugs in foliar evaluation study Treatment Total Insects Total Insects/ 30 Sweeps Total Insects/ 30 Sweeps Total Insects/ 30 Sweeps Total Insects/ 30 Sweeps August 19 August 3 July 24 July 7 Foliar Applications Foliar Applications Foliar Applications Foliar Applications Foliar Applications Foliar Applications 20 4 1 Pay Off 2.5EC 15 0 2 Pay Off 2.5EC 29 7 3 Ammo 2.5EC 14 0 1 FMC-54800 0.8EC 29 2 FMC-54617 0.8EC 2 0 Ambush 2E 6 2 Pydrin 2.4EC 0 0 Sum. S-3206 2.4EC 7 2 L-676863 0.03EC 0 2 FCR-1272 200EC 0 0 Monitor 4EC 1 3 Lorsban 4EC 11 8 15 7 6 11 6 15 14 9 8 17 Soil SystemicsSoil SystemicsSoil SystemicsSoil Systemics 0.05 0.10 0.05 0.04 0.04 0.10 0.10 0.10 0.01 0.05 0.75 1.00 47 21 21 19 47 19 17 20 4 5 4 6 10 8 7 4 24 8 9 7 Soil Systemics BAS-263-11 10G Temik 15G Untreated Untreated Soil SystemicsSoil Systemics 3.00 3.00 -- -- 4 1 1 0 11 0 10 18 16 3 0 0 17 8 9 6 48 12 20 24 Total Insects/30 Sweeps July 24 La Total Insects/30 Sweeps August 3 Ad Total Insects/30 Sweeps Total Insects/30 Sweeps August 19 La August 3 La Total Insects/30 Sweeps Total Insects Ad August 19 Ad Total Insects La July 7 Ad Table 2. Control of Colorado potato beetle adults and larvae Treatment Total Insects/30 Sweeps Foliar application Total Insects/30 Sweeps July 7 La Total Insects/30 Sweeps July 24 Ad Foliar applicationFoliar application Foliar application Pay Off Pay Off Ammo FMC-54800 FMC-54617 Ambush Pydrin S-3206 L-676863 FCR-1272 Monitor Lorsban Foliar application 25 27 8 23 11 51 22 42 23 14 46 37 Foliar application Foliar application Foliar application 25 13 16 7 16 7 13 26 6 10 8 9 32 56 6 28 11 146 51 28 6 21 42 15 1 3 1 0 0 1 0 0 2 0 0 0 1 - 2 - - - - - - - - Soil SystemicsSoil SystemicsSoil Systemics Soil Systemics Foliar application Foliar application 81 66 23 55 17 196 64 63 8 23 73 26 56 52 30 36 41 73 54 77 39 29 76 49 Soil Systemics 11 6 5 0 214 251 198 233 1040 1185 empty table cell empty table cell Soil SystemicsSoil Systemics 6 0 78 114 640 77% 37 9 10 21 5 46 9 19 2 0 29 11 5 9 5 6 14 14 19 9 8 5 22 3 Soil Systemics 3 3 63 89 277 80% 11 1 5 6 1 4 4 16 0 2 2 0 Soil Systemics 0 0 11 5 68 20% 0 0 162 114 474 98% Foliar application Soil SystemicsSoil Systemics BAS-263-11 Temik Untreated Untreated Totals Percent 0 0 0 0 8 2% 3 2 140 90 564 99% - 5 - 0 - 11 - 19 3 191 1% 23% Table 3. Yields and specific gravity of tubers from foliar evaluation study Material and Formulation Rate (ai) per A Yield per A Percent by Percent by Grade Size Grade Size A's B's Percent by Grade Size 10 oz Percent by Grade Size Off Type Spec Grav Foliar Applications 61% Foliar Applications 17% Foliar Applications 10% Foliar Applications 1.080 418 cwt Foliar Applications Foliar ApplicationsFoliar Applications Foliar Applications 12% Pay Off 2.5EC 372 15 Pay Off 2.5EC 9 Ammo 2.5EC 448 10 FMC-54800 0.8EC 421 14 FMC-54617 0.8EC 397 11 Ambush 2E 11 Pydrin 2.4EC 10 Sum. S-3206 2.4EC 8 L-676863 0.03EC 9 FCR-1272 200 EC 11 Monitor 4EC 12 Lorsban 4EC 64 64 69 64 65 64 64 67 62 67 66 Soil Systemics Soil Systemics 0.05 lb .10 0.05 0.04 0.04 .10 .10 .10 0.01 0.05 0.75 1.0 Soil Systemics 407 399 405 435 356 348 374 Soil Systemics 12 20 14 12 18 18 19 15 21 14 14 , , 9 1.080 empty table cell 1.083 empty table cell 1.080 , 1.080 1.083 1.079 1.077 1.080 1.080 1.079 1.079 10 8 8 8 7 Soil Systemics Soil Systemics Soil Systemics Soil Systemics BAS-263-11 10G Temik 15G Untreated Untreated 3.0 3.0 -- -- 424 488 320 328 11 8 14 13 62 63 72 68 17 12 21 8 10 7 8 6 1.079 1.081 1.080 1.079 BIOLOGY AND CONTROL STRATEGIES FOR INSECT PESTS OF POTATOES 1981 Research Report to the Michigan Potato Industry Commission E. Grafius and M. A. Otto Department of Entomology Michigan State University Research emphasis in 1981 was placed on continuing to gather information on control and impact of cutworms in Michigan potatoes. Sex attractant trap catches of adult male variegated cutworms in 1981 were much higher than in 1980, indicating the potential for damaging infestations in Michigan potatoes. Since the last outbreak year was 1977, it was imperative that additional data be collected. Although directly comparable results are not available for potatoes, trap catch records from celery in 1980 and 1981 clearly show the increased adult flight activity in 1981 and also the comparatively long duration of peak flight activity (Fig. 1). The objectives of the field research were to: 1) continue evaluation of the effect of variegated and other cutworms on tuber yield and tuber damage and 2) assess the relative effectiveness of grower applied insecticides in terms of cutworm population reduction and prevention of yield loss and/or tuber damage. Methods Research plots were established at the Montcalm Co. research farm, and commercial fields in Montcalm and Presque Isle Counties. At the Montcalm Co. research farm, cutworm larvae or egg masses were obtained from laboratory culture and released in the center row of 5 row plots of Onaway, Monona and Russet Burbank potatoes. An average of 16 eggs per plant were released in the center row of the Onaway and Monona plots and 50 eggs per plant in the Russet Burbank plots. Cutworm counts and yield data were taken from the release row and 1-5 or more rows away from the release row. Cutworm densities were expected to decrease gradually away from the row where they were released, giving rows with different population levels. In the commercial fields in Montcalm Co. (cv. Russet Burbank; John Crawford, cooperator) and in Presque Isle Co. (non-irrigated; cv. Ontario; Jerry Kroll, cooperator), cutworm densities were monitored in treated and untreated plots. Yield and damage estimates were taken at harvest. Various estimates of % foliage loss were also taken, however, these data are not fully analyzed at this time. In the Montcalm field, foliage loss averaged approximately 10%, a conservative estimate of the economic injury level, at the time of the last insecticide treatment (Pydrin) . In the Presque Isle field, foliage loss in the untreated plots was also approxi­ mately 10%. Results Population estimates from the release rows and adjacent rows at the Montcalm Co. research farm showed very low survival of cutworm larvae (less than 1 per plant in the release rows) and little defoliation. Yield results reflected the low population densities and there were no significant effect of cutworms on yield even in the release rows (Table 1) . Although no insecticides had been applied to the plots for 1 or more weeks prior to the cutworm releases, residual material may have been present. It is thought, however, that natural mortality of eggs and larvae is very high and that natural enemies and/or weather conditions were responsible for the low larval survival. Larval densities in the Montcalm Co. commercial field averaged nearly 7 variegated and spotted cutworms per plant prior to treatment (Table 2). Black cutworms were also present in very low numbers. Parathion and Sevin were applied in treatment 2, as soon as larvae were detected and followed 1 week later with a parathion treatment. Pydrin was applied in treatment 1 when foliage losses had reached approximately 10% and high cutworm densities were still present. In Presque Isle Co. , a field (cv. Ontario) was located with a fairly uniform density of 3.3 + .80 variegated cutworms per plant. That population was considered an economic threat for several reasons. The plants were small (drought), defoliation already averaged slightly more than 5%, the cutworm population was just getting to the final larval stage where most of the feeding is done, and the plants were just starting into the tuber bulking stage. Pydrin and Lannate both appeared to effectively reduce the cutworm population levels (Table 3) . However, this did not significantly increase yields or reduce tuber feeding damage (Table 3). Conclusions As the result of the Montcalm Co. research farm releases, it is suggested that egg and/or early larval mortality due to natural enemies or climatic factors is much higher than had been previously thought. This may explain why cutworms and particularly variegated cutworms are sporadic problems even in outbreak years such as 1981 and are rarely a problem in years of average adult flights and oviposition. Results from the commercial fields demonstrated that considerable foliage loss can be tolerated without significant yield reductions. Cutworm densities of 3 larvae or more per plant apparently cause little or no yield losses even in non-irrigated potatoes. Tuber damage occurred only sporadically even in the Presque Isle field where conditions were very dry, foliage was not lush, and larvae in untreated plots were allowed to reach maturity. Black cutworms were generally less abundant in 1981 than in previous years. These factors support the hypothesis that foliar feed­ ing cutworms are not a major cause of tuber damage, whereas black cutworms (although generally less numerous) are the cause of most tuber damage. Results from research plots and other commercial fields indicate that adequate control can be obtained either by carefully timed treatments of parathion and Sevin or through the use of materials such as Pydrin, Lannate, or Monitor for control when larvae are larger and defoliation becomes noticeable. Since outbreaks cannot be reliably predicted from year-to-year or field-to-field, the latter approach, combined with routine scouting of fields is recommended. It is concluded that with current programs of field scouting and the avail­ ability of several highly effective materials, foliar-feeding species such as variegated and spotted cutworms are not as severe a problem as they were even a few years ago. Figure 1. Comparison of sex attractant trap catches of adult male variegated cutworms between 1980 and 1981 from traps in celery fields in West-central Michigan (Allegan, Hudsonville, Byron Center, etc). Julian date 182 corresponds to June 1. Effect of Distance from Variegated Cutworm Release on Yield1 Table 1 Onaway2 Onaway 2A Over 2 A+O Onaway A Monona2 Monona 2 Monona2 Over A+O Rows away from release Russet Burbank3 Russet Burbank A 3 Russet Burbank3 Jumbo A+J 0 1 2 3 4 5+ 6+4 90.1 92.3 98.6 89.2 89.9 87.9 - 33.3 33.4 30.1 30.8 29.8 35.6 - 123.8 125.9 119.8 120.0 119.7 123.5 - 87.1 91.1 91.9 92.0 87.3 90.1 - 30.5 30.7 21.9 26.1 30.5 25.5 - 117.6 121.8 123.8 118.1 117.8 115.6 - 82.3 85.8 80.0 - - - 87.1 15.5 15.2 15.9 - - - 18.1 100.7 101.1 95.9 - - - 105.2 1Yield expressed as lb. per 50 row ft. 2Onaway and Monona varieties had two releases (July 11 and July 24) averaging 8 eggs per plant on each date. 3Russet Burbank variety had 5 releases (July 18, 24, 31; Aug. 7 and 14) averaging 10 eggs per plant on each date. 4Beginning with row 6 in the Burbanks, foliar insecticides were applied to prevent all cutworm damage. Table 2 Effects of Control Options on Cutworm Populations and Yield at Harvest for Russet Burbank Potatoes in Montcalm Co. Date Treatment 1 1 Cutworm Density and Stage3 Spotted Cutworms # / plant Treatment 1 1 Cutworm Density and Stage3 Spotted Cutworms stage Treatment 2 2 Treatment 1 1 Treatment 1 1 Treatment 2 2 Treatment 1 1 Cutworm Density and Stage3 Cutworm Density and Stage3 Cutworm Density and Stage3 Cutworm Density and Stage3 Cutworm Density and Stage3 Varie­ Spotted Total Variegated Variegated # / plant Cutworms Cutworms gated # / plant stage # / plant # / plant Treatment 2 2 Cutworm Density and Stage3 Total # / plant 7/8 0 - 0 - 0 0 3.4 4.1 not sprayed not sprayed 2.8 4.2 6.3 not sprayed not sprayednot sprayed 2.1 4.9 4.6 3.5 1.4 not sprayednot sprayed not sprayed not sprayednot sprayed 7.0 4.5 4.5 5.7 2.4 0 0 same as treatment 1 same as treatment 1 same as treatment 1 sprayed with 1 pt. parathion 80S sprayed with 1 pt. parathion + 1.25# Sevin + 1.25# Sevin 80S Sevin 80S sprayed with 1 pt. parathion + 1.25# 0.5 l.l 1.7 sprayed with 1 pt. parathion sprayed with 1 pt. parathion .sprayed with 1 pt. parathion 1.0 2.0 3.0 7/15 7/17 7/224 7/24 7/29 7/31 8/5 8/12 sprayed with 7 oz. Pydrinsprayed with 7 oz. Pydrin sprayed with 7 oz. Pydrin sprayed with 7 oz. Pydrin sprayed with 7 oz. Pydrinnot sprayed not sprayed not sprayed 0.1 - 0.03 6.0 0.6 0.03 - 6.0 0.7 0 2.2 2.2 0.06 0 0.03 0.03 Yield (lb./10 row ft.) empty table cell empty table cell A's Jumbos5 A’s + Jumbos Off types B’s 16.8 1.9 18.7 3.2 3.4 14.3 3.1 17.4 4.6 3.8 1Treated with 13.3# Temik at planting. 2Treated with 20# Temik at planting. 3Stage estimated as average instar; instar 1 = newly hatched, instar 6 = mature. 4This figure includes rows affected by spray drift from treatment 2.5 Yield of jumbos was significantly higher in treatment 2 (t-test, P < 0.05). Table 3 Effect of Insecticide Treatments on Variegated Cutworm Density, Tuber Yields and Tuber Feeding Damage empty table cell Cutworm Density3 --8/5 Lannate2 Pydrin1 Pydrin Ck 2.0 0 0 Lannate Ck 1.0 Yield4 % Tuber Feeding 12.2 10.9 0 A's .1 % Tuber Feeding B’s .76 .83 9.9 .23 .98 10.6 1.0 .08 1. Applied on July 24 at 5 oz./A 2. Applied on July 24 at 5 oz./A 3. Density is expressed as the # of cutworms per plant. Pre-treatment density was 3.3 + .8053 and the cutworms averaged 5.6 instar or nearly mature. 4. Lbs. A’s/ 10 row ft. cv Ontario. POTATO IRRIGATION STUDY J.M. Jenkins and M.L. Vitosh Department of Crop and Soil Sciences Introduction At the present time growers have very little information available to them for the improvement of their irrigation management practices. With 80% of Michigan’s potato crop under irrigation and in view of the rapidly rising cost of irrigation, filling this void in our knowledge is of obvious importance. This study examines the response of three different varieties of potatoes to various levels of irrigation. The objectives were to gain information on rates of water use by the crop through the season; to evaluate yield and tuber quality under different water regimes; to determine what information growers can currently use and evaluate options available for disseminating this information. Procedure The Michigan State Soils Research Farm was the site of this experiment. Within the experimental area there were three ranges each having a different potato variety, Superior, Atlantic, or Russet-Burbank. Each plot was arranged with a discard row between each pair of harvest rows. Differing rates of water were applied by a single irrigation line running down the center of the plot with risers at ten foot spacings. This arrangement results in a triangular shaped distribution pattern with the rows closest to the line receiving the max­ imum rate of water (100 %) and the rows further away receiving progressively less. The outside rows got no irrigation water (0%). Tensiometers and a neutron probe provided soil moisture measurements. In each range one row from each of the moisture regimes had two tensiometers, one at nine inches and one at 18 inches. Two neutron probe access tubes were in harvest rows of the 100%, 66% and 0% moisture regimes within each range. This gave a total of 6 access tubes in each range. The tensiometers were read three times per week while neutron probe read­ ings were taken once a week at each access tube. It became clear early in the summer that it would only be possible to maintain tension in the tensiometers at the 100% irrigation level. Due to the dry conditions the others ceased to func­ tion. Irrigation began when the tensiometers at the 100% moisture level showed 50 centibars tension. Only a half inch of water could be applied at a time without runoff occurring due to the high rate of application along the irrigation line. The second part of this project was to evaluate our ability to help growers schedule irrigation water. Three outstate sites were selected for this study. At each of these sites the neutron probe and tensiometers monitored soil mois­ ture. From this data, recommendations were made on the timing and amount of the next irrigation. Results Tables 1 and 2 show the yield results for the Superior and Atlantic varieties. While there are strong trends towards maximum yields with maximum water rates, statistically significant yield reductions did not occur until the irrigation was below 83% (5.1") in the Atlantics. Total yield and U.S. #1's appear to be relatively sensitive to reductions in water. Oversize tubers in Superiors were significantly reduced with less than 66% (4.1") irrigation water. This yield reduction was not seen in the Atlantics. Undersize and specific gravities were generally much less sensitive to the same conditions. Table 3 shows the yield results for the Russet Burbank variety. The max­ imum rate of water (7.7") shows a large, though not statistically significant, drop in yield compared with the 83% (6.4") level. This can largely be attri­ buted to heavy early blight in the Treatment 1 harvest rows. This variety shows the highest sensitivity to reduced water with the U.S. #1's and the off-types. Off-types greatly increase with dryer conditions. Total yields and specific gravities were moderately sensitive to lower water while oversize and under size yields were fairly insensitive. Figure 1 shows the comparison between our cumulative evapotranspiration (ET) estimates and cumulative water (rain + irrigation). Irrigation applica­ tions were carried out according to the soil moisture instruments yet the cumu­ lative water did not keep up with the cumulative ET estimates through the sea­ son. The difference widened especially on days where there was significant rainfall. This suggests that our ET estimates are too high. Adding a relative humidity and possibly a solar radiation term to our ET equation may help bring the ET estimates in line with the actual soil moisture losses. Figures 2-4 show tensiometer readings for the three ranges and Figures 5-7 show neutron probe readings for three treatments at five depths for the three ranges. These graphs plot the soil moisture fluctuations seen in the experimen­ tal plot. Be sure that the y-axis on each graph is clearly understood when mak­ ing comparisons between graphs. Outstate Scheduling Experiment The data for these studies are shown in Figures 8 and 9. Figure 8 shows cumulative estimated ET and water for the Alan Anderson Farm. Cumulative water was less than cumulative ET during July but rains at the end of July and begin­ ning of August alleviated this difference. Figure 9 shows the tensiometer read­ ings for this field. It is clear that soil moisture was adequate. For this farm ET estimates appear quite good. When the ET prediction equa- tion includes only a few climactic factors, there can be great variability in the accuracy of the ET estimates depending on the localized climates. Table 1. Yield results for Superior variety TRT Irrigation Water % (inches) Over Size cwt/A U.S. #1 cwt/A Superior Under Size cwt/A Total cwt/A Specific Gravity 1 2 3 4 5 100% (6.2) 51.7a1 377.6a 15.0a 444.3a 1.075a 83 (5.1) 52.3a 361.4a 12.5a 426.2ab 1.075a 66 33 (4.1) 48.9ab 326.1 b 14.6a 389.6 b 1.076a (2.0) 33.2 b 278.3 c 12.5a 323.0 c 1.078a 0 (0) 16.0 c 216.8 d 14.3a 247.1 d 1.078a LSD (.05) - empty table cell 16.5 32.6 4.5 39.8 .006 1Means followed by the same letter are not statistically different as determined by the Least Significant Different Test (P = 0.5). Table 2. Yield results for Atlantic variety. TRT Irrigation Water % (inches) Over Size cwt/A U.S. #1 cwt/A Atlantics Under Size cwt/A Total cwt/A Specific Gravity 1 2 3 4 5 100% (7.7") 96.6a1 382.2a 23.9a 502.7a 1.091a 83 66 (6.4) 97.0a (5.1") 97.0a 355.9a 353.3a 21.0ab 20.7ab 473.9a 1.092a 471.0a 1.089a 33 (2.5") 83.6a 304.1 b 20.8ab 408.5 b 1.086a 0 (0) 59.0 b 273.5 b 19.2 b 376.7 b 1.089a LSD (.05)- empty table cell 21.5 32.0 4.2 41.0 .006 1Means followed by the same letter are not statistically different as determined by the Least Significant Difference Test (P = 0.5). Table 3. Yield results for Russet Burbank variety. TRT Irrigation Water % (inches) Off Type cwt/A Over Size cwt/A U.S. #1 cwt/A Under Size cwt/A Total cwt/A Specific Gravity Russet Burbank 1 2 3 4 5 100% (7.7") 60.7a1 17.7a 302.6a 50.1a 431.0ab 1.080a 83 66 (6.4") 123.9 b 13.8a 288.7ab 36.7 b 467.2a 1.078a (5.1") 159.1 b 10.8ab 235.4 b 44.6 ba 449.9ab 1.075ab 33 (2.5") 210.0 c 0.8 b 154.5 c 51.3a 416.6 bc 1.073 b 0 (0) 214.3 c 0.0 b 107.3 c 56.6a 377.8 c 1.072 b LSD (.05) empty table cell 48.3 10.9 66.6 12.5 45.0 .004 1 Means followed by the same letter are not statistically different as determined by the Least Significant Difference Test (P = 0.5). Fig 1: Comparison of Cumulative Estimated ET and Water Fig 2 : Tensiometer Readings for Range I Fig 3: Tensiometer Readings for Range II Fig 4: Tensiometer Readings for Range III Fig 5 : Range I Neutron Probe Readings (% Volumetric Moisture) At Five Depths for Treatments 1(A), 3(B), and 5(C) Fig 6 : Range II Neutron Probe Readings at Five Depths for Treatments 1(A), 3(B), 5(C) Fig 7: Range III Neutron Probe Readings at Five Depths for Treatments 1(A), 3(B), 5(C) Fig 8: Comparison of Cumulative Estimated ET and Water Fig 9: Tensiometer Readings for the Alan Anderson Farm PRODUCTION AND MANAGEMENT FACTORS TO MAXIMIZE SPECIFIC GRAVITY AND THE USE OF CARBOHYDRATE ANALYSIS TO DETERMINE HARVEST MATURITY AND PROCESSING QUALITY OF MICHIGAN POTATOES J.N. Cash and R.W. Chase Departments of Food Sciences & Crop and Soil Sciences In 1979 and 1980 the potato varieties Atlantic, Belchip, Denali, Monona and Norchip were grown at the Montcalm Research Farm. In 1980, Russet Burbank was also added and in 1981, Red Pontiac was included in the study. In 1979, each of the varieties was grown at nitrogen levels of 120, 200 and 280 pounds per acre. In 1980 and 1981, the nitrogen levels were 170 and 240 pounds per acre. Varying nitrogen levels did not elevate yield increases in any of the varieties tested and there were no statistical differences in sucrose or specific gravity between varieties due to nitrogen. Therefore, the data reported are averages of the nitrogen levels for each year. The data for 1979 and 1980 have been discussed in previous reports. Harvesting of tubers in 1981 began on August 3 (87 days after planting) and continued at biweekly intervals until October 14 (159 from planting). At each harvest date, sugar changes were determined by a standard sucrose rating (SR) technique and by high pressure liquid chromatography (HPLC) analysis for glucose and fructose. Crop growth during 1981 appeared to develop at a more accelerated rate than noted in previous years. Nearly all the varieties in the study reached a maximum marketable yield by late August, which sharply contrasts with 1980 when several of the later maturing cultivars continued to increase yields into late September. Figures 8-13. Specific gravity followed a similar trend, with maximum levels being attained by mid August. There was a general decline with delays in harvest. Previous work, using the SR for predicting storage stability, has shown that an SR of 2.8 or less is desirable for good processing potatoes (although more recent work seems to indicate that this maximum level should be lowered in many instances). All the varieties except Red Pontiac maintained sucrose contents below the 2.8 level throughout the season. All the chipping varieties (Atlantic, Belchip, Denali, Monona and Norchip) had minimal sucrose levels at the early harvest dates, further corroborating the early maturity of these tubers. Chip quality for the chipping varieties was very acceptable at all harvests, although soil temperatures were below 50°F during most of the first two weeks in October. Figure 1. Date and Days after Planting - Montcalm Research Farm 1981 The marketable yield and specific gravity of Atlantic grown at two nitrogen levels and harvested on different days after planting. Figure 2 Date and Days after Planting - Montcalm Research Farm 1981 The marketable yield and specific gravity of Belchip grown at two nitrogen levels and harvested on different days after planting. Figure 3. Date and Days after Planting - Montcalm Research Farm 1981 The marketable yield and specific gravity of Denali grown at two nitrogen levels and harvested on different days after planting. Figure 4 Date and Days after Planting - Montcalm Research Farm 1981 The marketable yield and specific gravity of Monona grown at two nitrogen levels and harvested on different days after planting. Figure 5 Date and Days after Planting - Montcalm Research Farm 1981 The marketable yield and specific gravity of Norchip grown at two nitrogen levels and harvested on different days after planting Figure 6 Date and Days after Planting - Montcalm Research Farm 1981 The marketable yield and specific gravity of Russet Burbank grown at two nitrogen levels and harvested on different days after planting. Figure 7 Date and Days after Planting - Montcalm Research Farm 1981 The marketable yield and specific gravity of Red Pontiac grown at two nitrogen levels and harvested on different days after planting. Figure 8 Date and Days after Planting - Montcalm Research Farm 1980 Figure 9 Date and Days after Planting - Montcalm Research Farm 1980 Figure 10 Date and Days after Planting - Montcalm Research Farm 1980 Figure 11 Date and Days after Planting - Montcalm Research Farm 1980 Figure 12 Date and Days after Planting - Montcalm Research Farm 1980 Figure 13 Date and Davs after Planting - Montcalm Research Farm 1980 THE INFLUENCE OF SELECTED PRODUCTION MANAGEMENT PRACTICES ON THE YIELD, QUALITY AND STORABILITY OF POTATOES M. L. Vitosh, G. W. Bird, R. Hammerschmidt, R. W. Chase, E. Grafius and H. C. Olsen Departments of Crop and Soil Sciences, Entomology and Botany-Plant Pathology The objective of the 1981 study was to optimize the inputs required for maximum tuber yield and quality. From 1977 to 1980 a series of experiments were conducted to examine various nutrient-nematicide interactions. The 1981 experiment was a culmination of this information plus an additional component, crop rotations. Superior, Russet Burbank and Denali potatoes were involved in corn and alfalfa rotations, METHODS In the spring of 1980 one range of corn and one range of alfalfa were planted side by side. The alfalfa was cut periodically and the top qrowth was left for soil organic matter accumulation. The corn was harvested for grain and the stalks were left in the field. Both ranges were plowed the last week of April, 1981. The plots that required fumigation received 10 gallons of Vorlex per acre chiseled in at an eight inch depth on April 28. All other plots received the same tillage, but no Vorlex was added. Treatment appli­ cations and planting were completed for the corn range on May 14, 1981 and for the alfalfa range on May 15. Each plot consisted of four rows 50 feet long having a 34 inch row width and 8 to 12 inches between seed pieces. Superior potatoes were to be evaluated using a 2X4 factorial design with five replications. Russet Burbank and Denali potatoes received only the highest levels of inputs. Temik 15G at 3.0 lbs. active ingredient per acre was added at-planting, in a band beside the seed furrow, to the plots that required aldicarb. Fertilizer was banded two inches to the side and two in­ ches below the seed pieces. All plots received 150 lbs. K2O per acre and 150 1 bs. P2O5 per acre. There were two nitrogen treatments, 75 and 225 lbs. N per acre. All plots received 75 lbs. N/A at-planting but the high N (225 lbs. N/A) plots received two side-dressings of 75 lbs. N/A each. The nitrogen form used was Urea. Soil nutrient levels were sampled at planting. Plant nutrient composi­ tion was determined by sampling petioles on June 30 and their subsequent an- laysis. Nematodes were sampled at-plant, 5-14, and on 6-15, 7-27, and 8-26. Nematodes were extracted from soil samples using the centrifugation-flota­ tion technique and the roots were processed using the giratory shaker tech­ nique. Fungi were sampled on 6-15, 6-30, 7-15, and 7-30. Stem sections were sampled at the soil surface level for lab analysis to determine the presence of Rhizoctonia spp. and Verticillium spp. Insects were monitored weekly to properly time foliar insecticide sprays and minimize insect damage. The center two rows of each plot were harvested, graded and weighed. The corn rotation range was harvested on August 25 and the alfalfa range was harvested the next day. RESULTS The Russet Burbank and Denali varieties were unintentionally killed shortly after the Superiors were harvested. As a result the yields were uncharacteristically low and only the nutrient composition data are provi­ ded for these varieties in this report. Marketable Tubers: Tuber Yields Following Alfalfa Marketable tubers are tubers greater than two inches in diameter hav­ ing no signs of rotting, graded comming off the harvester. At the low level of nitrogen, Temik and Temik plus Vorlex significantly (P=0.05) increased yields above the low N check (Table 1). Vorlex did not significantly in­ crease yields at either level of N. Temik at the high level of N signifi­ cantly increased tuber yields above all the low N treatments as well as the high N check (no nematicides) and Vorlex treatments. Temik plus Vorlex with high N significantly increased yields above all treatments except the high N Temik. Temik plus Vorlex increased yields by 69 cwt/A at the low N level and 105 cwt/A at the high N level, above the respective checks. Temik increased yields by 59 cwt/A at the low N level and 66 cwt/A at the high N level. Oversized Tubers: Temik with 225 lbs. N/A significantly increased tuber yields over all the 75 lb. N/A treatments plus the check and Vorlex with high N (Table 2). Temik plus Vorlex significantly increased tuber yields over the low N check. Tuber yields for the high N check, Temik, and Temik plus Vorlex were 42, 72 and 61 cwt per acre, respectively. 'b' Sized Tubers: There was a small range of differences in tuber yields (Table 3). The lowest was the check at 225 lbs. N/A which yielded 10 cwt/A and the highest was Temik plus Vorlex at the low N level yielding 14 cwt/A, these two treatments were the only ones significantly different. Specific Gravities: The specific gravities were not significantly affected by the treat­ ments (Table 4). Marketable Tubers: Tuber Yields Following Corn Nematicides did not affect yields at the 75 lb. N/A level, nitrogen was a limiting factor (Table 1). Raising the nitrogen application level to 225 lbs. N/A did not significantly increase yields in the absence of nema­ ticides. However, high N in the presence of Temik or Vorlex increased the yields above the low N check by 84 and 76 cwt/A, respectively. Temik plus Vorlex significantly increased yields above all the low N treatments and the high N check, the yields were increased 119cwt over the low N check and 89 cwt over the high N check. Oversized Tubers: Again nematicides had no significant impact on tuber yields at the low level of nitrogen (Table 2). With the application of 225 lbs. N/A both Vor­ lex and Temik treatments significantly increased tuber yields above all the low N treatments and the high N check. The tuber yields in the Temik plus Vorlex treatment were significantly greater than all other treatments. 'b' Sized Tubers: The production of 'b' sized tubers was significantly reduced in all treatments by raising the N level to 225 lbs. per acre (Table 3). Specific Gravities: Raising the N level significantly reduced the gravities in all but the Vorlex treatment (Table 4). Nutrients Nitrate nitrogen in potato petioles was directly related to the addi­ tion of nitrogen fertilizer (Tables 5 and 6). In the corn rotation the 75 lb. rate of N resulted in significantly lower nitrate (NO3) nitrogen in the potato petioles than 225 lbs. N/A. Slightly lower NO3 levels were found when Vorlex was used at the lower N rate. Vorlex, a soil fumigant, probab­ ly reduced mineralization of soil organic matter and may also have delayed nitrification, conversion of ammonium nitrogen (NH4) to NO3. Other research has shown that potatoes prefer the NO3 form of nitrogen over the NH4 form. Higher levels of NO3 were found in the alfalfa rotation, particularly at the lower levels of N fertilizer. 75 lbs. N/A appeared to be adequate at the time of this early sampling. Calcium and magnesium concentrations were significantly increased in the corn rotation when 225 lbs. N/A was added, particularly when Temik and Vorlex were added. This relationship did not exist in the alfalfa rotation and is not immediately clear. All other nutrients analyzed were not signi­ ficantly affected by any of the treatment combinations. Biotic Components Nitrogen levels had no significant effect on the biotic components monitored (Table 7). VerticiIlium spp. levels were not significantly af­ fected by any single treatment combination (Tables 8 and 10). Rhizoctonia spp., though only significant in the alfalfa rotation in June 30, showed a trend toward higher infection levels in the nematicide treatments as com­ pared to the checks (Tables 9 and 11). Symptoms of either pathogen did not appear sever on any treatments during the growing season. Pratylenchus pen­ etrans, the root-lesion nematode, was present at low numbers in all the plots at planting, May 14 (Table 12). Treatment with Temik 15G resulted in season long control of the nematodes, the population densities were significantly lower than the check or Vorlex in both of the rotations on July 27 (Table 13). At this sampling date we expect the nematodes to be at their highest seasonal population levels on Superior. In the corn rotation the use of Vorlex resulted in some nematode control but not in the alfalfa rotation. Table 14 compares some of the treatment effects on pathogens and yields. The two nitrogen levels were averaged together in Table 15 to illus­ trate the main effects of the nematicides. When the data are compared in this manner nematicides had a significant impact of fungal infection in the alfalfa rotation. Rhizoctonia levels show the same trend as mentioned be­ fore. Verticillium levels were significantly higher in the Vorlex treat­ ment than the other treatments in the alfalfa rotation. ECONOMIC COMPARISONS In order to make the results of this experiment more useful we have attempted to standardize the treatments by putting them on a cost per unit return. To examine the effects of each treatment independent of all the other inputs that influenced the tuber yields one can compare the results from a treatment to the results of its check. The check receives all the same inputs except the added treatment itself. In examining the dollar returns of each treatment we treat the check as a base level, or zero re­ turns. The treatments will result in yield changes from the check and costs over the check, which effect the net returns. In figure 1 the amount that a treatment increased tuber yields over its respective check is multiplied by a chosen market value then the cost of the treatment itself is subtrac­ ted to obtain the net returns per acre above what the check would provide. In other words, the check is the X axis, zero returns. If the market val­ ue per cwt is $3.00 all treatments except Vorlex resulted in a net return above their respective check, whether high N or low N. Figure 2 illustrates the effects of the treatments following corn. At a market value of $3.00, at 75 lbs N/A only Temik provides a net return above the check. Again, the use of Vorlex at 10 gal/A with a market value of $3.00 resulted in a net cost at either N level. Figures 3 and 4 allows one to estimate the net returns of the high N treatments when the low N check is considered as the base level of returns. Figures 1 through 4 allow oneto observe the marketable tuber yield re­ sponses with a different perspective. However, only those treatments which resulted in significantly different marketable tuber yields (Table 1) should be viewed as having differences in net returns until further analy­ sis is completed. Figures 5 through 7 illustrate the same type of relationships except total returns per acre, with only the costs of nitrogen and nematicides sub­ tracted, are used on the Y axis. From these figures one can obtain the total returns of the checks that were used as a base level for the previous figures. Due to the experimental design the corn and alfalfa rotations cannot SUMMARY be directly compared. However, the relationships of the treatment results within rotations indicate the responses to be expected from the crop rota­ tion. These relationships illustrate the differences in the dynamics of the two systems, of which there are many. Caution should be exercised in pre­ dicting responses based on the results of just one year's data. Table 1. The influence of selected management practices on tuber yields of potatoes (cv Superior). Marketable Tuber Yields 1981 Treatments lbs N/A Treatments Nematicide Rotation Alfalfa Rotation Corn -cwt/A- -cwt/A- 75 75 75 75 225 225 225 225 Check Vorlex Temik Temik & Vorlex Check Vorlex Temik Temik & Vorlex 319.2al 354.3abc 378.6bc 387.8bc 338.8ab 356.4abc 405.3cd 444.0d 275.la 304.6ab 305.9ab 310.0ab 305.0ab 351.3bc 359.7bc 394.0C 1Column means followed by the same letter are not significantly dif­ ferent (P=0.05) according to the Student-Newman-Keuls Multiple Range Test. Table 2. The influence of selected management practices on tuber yields of potatoes (cv Superior). Oversized Tuber Yields 1981 Treatment lbs N/A Treatment Nematicide 75 75 75 75 225 225 225 225 Check Vorlex Temik Temik & Vorlex Check Vorlex Temik Temik & Vorlex Rotation Alfalfa-cwt/A- 25.0a1 44.3ab 40.6ab 49.1ab 42.5ab 43.5ab 72.0c 61.3bc Rotation -cwt/A- Corn 8.3a 10.0a 7.4a 8.7a 17.2a 35.lb 42.lb 56.4C 1Column means followed by the same letter are not significantly different (P=0.05) according to this Student-Newman-Keuls Multiple Range Test. Figure 3. The influence of selected management practices on tuber yields of potatoes (cv Superior). Yields of Tubers Less Than Two Inches in Diameter Treatments Rotation lbs N/A Treatments Nematicides empty table cell Check 75 Vorlex 75 75 225 225 225 225 Temík Temik & Vorlex Check Vorlex Temik Temik & Vorlex Alfalfa 11.4ab1 -cwt/A- Rotation Corn -cwt/A- 22.3b 11.7ab 12.3ab 14.0b 10.0a 10.9ab 12.8ab 12.9ab 21.7b 22.8b 23.4b 14.4a 14.4a 16.3a 15.5a 1Column means followed by the same letter are not significantly dif­ ferent (P=0.05) according to the Student-Newman-Keuls Multiple Range Test. Table 4. Marketable tuber yields and specific gravities as affected by selected production management practices. Treatments Treatments Crop Rotation Crop lbs N/A Nematicide Crop Rotation Alfalfa sp. gr. Rotation Corn yields Crop Rotation Corn sp. gr. Alfalfa yieldsz 319.2a1 1.071a 275.1a 1.072b 354.3abc 1.070a 304.6ab 1.072b 378.6bc 1.069a 305.9ab 1.072b Check Vorlex Temik 75 75 75 225 225 225 75 225 Temik & Vorlex 387.8bc 1.069a 310.0ab 1.070b Check Vorlex Temik 338.8ab 1.071a 305.0ab 1.067a 356.4abc 1.072a 351.3bc 1.069ab 405.3cd 1.069a 359.7bc 1.067a Temik & Vorlex 444.0d 1.072a 394.0c 1.068a 1Column means followed by the same letter are not significantly different (P=0.05) accord­ ing to the Student-Newman-Keuls Multiple Range Test. zcwt/A Table 5. Effect of nitrogen rate and nematicides on nutrient composition of potato petioles from Superior, Russet Burbank and Denali potatoes grown in an alfalfa rotation. Nitrogen Rate lbs N/A 75 225 225 75 75 75 225 225 225 225 Nematicide Nematicide Nutrients1 Nutrients1 Temik Vorlex Variety 1 NO3 Nutrients Nutrients 1 P% Nutrients 1 K Ca% Mg % Nutrients 1 Znppm Nutrients 1 Fe Nutrients 1 Mnppm no no yes yes no no yes yes yes yes no yes no yes no yes no yes yes yes Superior " " " ppm 28,985a2 % .38a 9.19a 29,731ab .36a 9.29a 31,447abc .37a 8.80a .89a .89a .44a .47ab .90ab .47ab 28,999a 139a 9.00a .89a .48a Superior 34,314cde .35a 9.40a .91ab .48a " " " 32,165bcd 34,899cde 35,501e .32a 9.02a .90ab .50ab .40a 9.67a 1.05b .61b .36a 9.69a 1.01b .61b 56d 102a R. Burbank 31,008ab .40a 9.27a 1.03b .61b Denali 29,124a .29a 9.01a .79a 138a 51cd 41abc 90a 94a ppm 38abc 31a 35ab 42abc 37ab 37ab 47bcd 99a 94a 80a 88a 93a 89a 90a 127a 98a 106a 136a 129a 109a 134a 132a 172a 135a empty table cell empty table cell Sufficiency Levelsempty table cell 1Sampled June 30,1981 16,000- 20,000 .18- .22 6.0- 9.0 .36- .50 .17- .22 30- 100 30+ 30- 200 2Column means followed by the same letter are not significantly different (P=0.05) according to the least significant difference test. Table 6. Effect of nitrogen rate and nematicides on nutrient composition of potato petioles from Superior, Russet Burbank and Denali potatoes grown in a corn rotation. Nitrogen Nematicide Nematicide Nutrients1 Nutrients1 Nutrients1 75 75 75 225 225 225 225 Rate lb N/A 75 225 225 Temik Vorlex Variety 1 no3ppm Nutrients 1 P% Nutrients K Ca % Mg % 1 Znppm Nutrients Nutrients 1 Fe Nutrients 1 Mnppm % ppm no no yes yes no no yes yes yes yes no yes no yes no yes no yes yes yes Superior " 16,687a2 .51a 10.46a 14,906a .48a 10.11a .76a .71a " " 16,392a .43a 10.75a .76a 14,515a .41a 9.39a .66a Superior 27,230bc .44a 9.47a .68a 24,882b .42a 10.35a .74a " " " 29,140c 27,212bc .47a .42a .40a .44a 9.66a .79a 9.84c .76a 9.14a .67a 9.46a .64 R. Burbank 23,980b Denali 24,766b .33a .33a .31a .32a .34a .39a .38a .42a .36a .32a 55a 50a 66a 68a 73a 70a 68a 72a 82a 80a 138a 135a 129a 130a 141a 119a 140a 128a 113a 145a 242a 221a 274a 224a 244a 181a 217a 193a 231a 237a Sufficiency Levelsempty table cell empty table cell empty table cell 16,000- 20,000 .18- .22 6.0- .36- .17- 9.0 .50 .22 30- 100 30+ 30- 200 1Sampled June 30, 1981 2Column means followed by the same letter are not significantly different (P=0.05) according to the least significant difference test. Table 7. Marketable tuber yields and biotic components as affected by nitrogen levels. Rotation P. penetrans Rhizoctonia Verticillium lbs N/A Alfalfa Alfalfa Corn Corn cwt/A 360.0a1 386.1a 284.6a 352.5b 75 225 75 225 24.1a2 21.2a 12.4a 10.2a 30a3 17a 20a 8a 23a 23a 33a 35a 1Column means within rotation followed by the same letter are not signi­ ficantly different (P=0.05) according to the Student-Newman-Keuls Mul­ tiple Range Test. 2 P. penetrans per gram of root. Sampled 7/27/81. 3 Percent of plants infected. Sampled 6/30/81. Table 8. Percent of Superior potatoes infected with Verticillium following alfalfa in a crop rotation. lbs N/A Nematicide Date Sampled 6/15 Date Sampled 6/30 Date Sampled 7/15 Date Sampled 7/30 75 75 75 75 Check Vorlex Temik Temik & Vorlex 0a1 0a 7a 7a 20a 47a 27a 0a 20a 20a 27a 47a 67a 67a 60a 60a 225 225 225 225 Check Vorlex Temik Temik & Vorlex 73a 60a 60a 60a 1Column means followed by the same letter are not significantly differ­ 33a 20a 47a 20a 27a 53a 0a 13a 0a 7a 0a 13a ent according to the Student-Newman-Keuls Multiple Range Test. Table 9. Percent of Superior potatoes infected with Rhizoctonia following alfalfa in a crop rotation. lbs N/A Nematicide Date Sampled 6/15 Date Sampled 6/30 Date Sampled 7/15 Date Sampled 7/30 75 75 75 75 Check Vorlex Temik Temik & Vorlex 13a1 60a 60a 73a 0a 27ab 40ab 53b 13a 33a 40a 13a 40a 33a 20a 40a 225 225 225 225 Check Vorlex Temik Temik & Vorlex 20a 33a 40a 27a 1Column means followed by the same letter are not significantly differ­ 0a 7ab 20ab 40ab 0a 33a 47a 40a 73a 53a 73a 67a ent according to the Student-Newman-Keuls Multiple Range Test. Table 10. Percent of Superior potato plants infected with VerticiIlium following corn in a crop rotation. lbs N/A Nematicide Date Sampled 6/15 Date Sampled 6/30 Date Sampled 7/15 Date Sampled 7/30 75 75 75 75 225 225 225 225 Check Vorlex Temik Temik & Vorlex Check Vorlex Temik Temik & Vorlex 7 1 0 7 0 0 0 7 13 40 20 27 20 47 13 33 47 60 73 73 67 47 53 60 47 87 47 73 73 60 80 60 47 1Column means are not significantly different according to the Student- Newman-Keuls Multiple Range Test. Table 11. Percent of Superior potato plants infected with Rhizoctonia following corn in a crop rotation. lbs N/A Nematicide Date Sampled 6/15 Date Sampled 6/30 Date Sampled 7/15 Date Sampled 7/30 75 75 75 75 225 225 225 225 Check Vorlex Temik Temik & Vorlex Check Vorlex Temik Temik & Vorlex 0 1 7 13 20 0 7 20 0 7 27 27 20 0 7 13 13 7 20 13 7 0 0 27 27 0 7 13 27 7 7 7 13 1Column means are not significantly different according to the Student- Newman-Keuls Multiple Range Test. Table 12. The Influence of selected management practices on the population densities of penetrans. Initial Population Densities of the Root Lesion Nematode. Following: Alfalfa 2.4a aP. penetrans per 100 cm3 soil. Corn 3.1 Table 13. The influence of selected management practices on the population densities of P. penetrans. Pratylenchus penetrans per gram of root. (07/27/81) Treatments lbs/ N/A Treatments Nematicides Rotation Alfalfa Rotation Corn 75 75 75 75 225 225 225 225 Check Vorlex Temik Temik & Vorlex Check Vorlex Temik Temik & Vorlex a1 84.8 103.2a 2.8b 2.0b 72.8a 95.6a 0.4b 1.2b 80.0c 18.8b 0.4a 0.4a 55.6C 24.0b 0a 2.0a 1Column means followed by the same letter are not significantly dif­ ferent according to the Student-Newman-Keuls Multiple Range Test. Table 14. Marketable tuber yields of Superior and biotic components as influenced by selected production management practices. Rotation lbs N/A Alfalfa Alfalfa 75 75 Alfalfa 75 Alfalfa Alfalfa Alfalfa 75 225 225 Alfalfa 225 Alfalfa 225 Corn Corn Corn Corn Corn Corn Corn Corn 75 75 75 75 225 225 225 225 Nematicides Check Vorlex Temik Temik & Vorlex Check Vorlex Temik Temik & Vorlex Check Vorlex Temik Temik & Vorlex Check Vorlex Temik Temik & Vorlex cwt/A 319.2a3 354.3abc 378.6bc 387.8bc 338.8ab 356.4abc 405.3cd 444.0d 275.1a 304.6ab 305.9ab 310.0ab 305.0ab 351.3bc 359.7bc 394.0c P. penetrans1 Rhizoctonia2 Verticillium2 84.8b 103.2b 2.8a 2.0 72.8b 95.6b 0.4a 1.2a 80.0c 18.8b 0.4a 0.4a 55.6c 24.0b 0.0a 2.0a 0a 27ab 40ab 53b 0a 7ab 20ab 40ab 20a 27a 27a 7a 0a 7a 13a 13a 0a 27a 47a 20a 13a 0a 53a 27a 20a 27a 20a 40a 47a 33a 13a 47a 1 Pratylenchus penetrans, Root-lesion nematode, per gram of root tissue, sampled 7-27-81. 2 Percent of plants infected, sampled 6-30-81 3 Column means within crop rotation followed by the same letter are not significantly dif­ ferent (P=0.05) according to the Student-Newman-Keuls Multiple Range Test. Table 15. Marketable tuber yields and biotic components as affected by nematicides. Rotation Nematicide Alfalfa Alfalfa Alfalfa Alfalfa Corn Corn Corn Corn Check Vorlex Temik Temik & Vorlex cwt/A 329.0ab1 355.3bc 392.0cd 415.6d 289.8 Check 328.0ab Vorlex 332.8ab Temik Temik & Vorlex 352.0bc P.penetrans Rhizoctonia Verticillium 39.4b2 3 49.7b 0.8a 0.8a 33.9b 10.7a 0.1a 0.6a 0a3 17ab 30bc 47c 3a 17a 20a 17a 24a3 50b 13a 7a 43a 17a 30a 33a 1 Column means within rotation followed by the same letter are not sig­ nificantly different (P=0.05) according to the Student-Newman-Keuls Multiple Range Test. 2 P. penetrans per gram of root tissue, sampled 7/27/81. 3 Percent of plants infected, sampled 6/30/81. Figure 1. The Simple Effects of Nematicides in a Potato-Alfalfa Rotation Figure 2. Simple Effects of Nematicides in a Potato-Corn Rotation Figure 3. Figure 4. The Economic Effects of Nitrogen and Nematicides The Economic Effects of Nitrogen and Nematicides on Tuber Yields of Superior Following Alfalfa on Tuber Yields of Superior Following Corn Figure 5. Figure 6. The Influence of Nematicides on Superior Potatoes The Influence of Nematicides on Superior Potatoes at 75 lbs Nitrogen Following Alfalfa at 225 lbs Nitrogen Following Alfalfa Figure 7. The Influence of Nematicides on Superior Potatoes at 225 lbs Nitrogen Following Corn THE INFLUENCE OF SELECTED PRODUCTION MANAGEMENT INPUTS ON WEIGHT LOSS AND MARKET QUALITY OF SUPERIOR POTATOES STORED UNDER VARIOUS STORAGE ENVIRONMENTS B.F. Cargill * Department of Agricultural Engineering INTRODUCTION The MSU Integrated Potato Research Project is a joint project involving vari­ ous departments at MSU basically Crop and Soil Sciences, Entomology, Botany and Plant Pathology, Food Science and Agricultural Engineering. The project is con­ ducted in three phases: Production Phase: Entomology Crop and Soil Sciences Storage Phase: Agricultural Engineering Market Quality Analysis Phase: Agricultural Engineering Botany and Plant Pathology Food Science Superior potatoes were planted at the MSU Montcalm Potato Research Farm under the supervision of Dr. Richard Chase, Crop and Soil Sciences. There potatoes were planted using nine production management programs—basically an analysis of the influence of various levels of potassium (K20). The nine treatment plots were repli­ cated five times. The production management team cf researchers programmed, managed and analyzed the production phase through harvest. The results of the production phase were evaluated by crop yields and are reported by the production researchers. The storage phase of the Integrated Project begins at harvest. Superior pota­ toes from the nine treatments and five replications were stored on the MSU campus in storage cubicles at Food Science. Environmental conditions are monitored daily and periodic evaluations for weight loss and market quality are made throughout the storage season from harvest (August 19, 1930) until spring planting (May 8, 1981). One technique for evaluation of storability is seed viability. Representative samples of Superior potatoes from the nine treatments were planted at the Montcalm Potato Research Farm on May 8, 1981 and harvested September 15, 1981. Therefore, the storability phase of the MSU Integrated Project is one year out of phase of the other MPIC sponsored MSU potato projects. *The production phase of the Integrated Project which provided the potatoes for the storage phase involved MSU researchers M.L. Vitosh, G.W. Bird, E. Grafius, R.W. Chase, H.C. Olsen, H.S. Potter and others basically in the Departments of Crop and Soil Sicences, Botany and Plant Pathology and Entomology. PROCEDURE There are four basic evaluations for the storability connected with this phase: 1. Sucrose ratings at harvest 2. Weight loss during storage 3. Market quality after storage 4. Seed viability Seed Viability Phase: The Superior potatoes were harvested August 19, 1980. Two sample bags of approximately 25 lbs. each were obtained from three of the five replications and nine treatments (54 bags total). These bags were weighed at har­ vest and after suberization at 60°F (15.6°C) for 14 days. After suberization the storage temperature was lowered 5°F per week to 40°F. The potatoes were stored until May 4, 1981 (258 days). Weight loss and market quality determinations were made at the end of the storage period (May 4). Seventy-five sound tubers were randomly selected from each of the three replications and nine treatments (25 tubers from each of the three replications). The tubers from the three replications for a given treatment were combined into one bagged sample. These potatoes were planted May 8, 1981 at the MSU Potato Research Farm. The production management practices for the seed viability phase were supervised by the Crop and Soil Sciences Depart­ ment. The results are reported later in this report. Weight Loss Phase: Superior potatoes were stored for this phase at 40° and 50°F (4.5° and 100C) and 95% relative humidity. All the bagged samples were weighed at harvest, after suberization, and upon termination of storage. Bags from the nine treatments (3 replications) were specifically stored for weight loss determinations. These bags were weighed at three intervals during storage (at 133 days, 180 days and 227 days) and upon termination of this phase (May 4, 1981 at 258 days). Weight loss samples were removed from storage, weighed, and returned to storage immediately This is in contrast to market quality sample bags which were removed, evaluated , and discarded. The weight loss data is reported later in this report. Market or Tuber Quality Phase: Twelve sample bags (approximately 25 lbs. each) were obtained from each of the three replications and nine treatments (324 bagged samples were stored for the market or tuber quality evaluation). Storability for market quality was observed at two storage temperatures 40° and 50°F (4.5° and 10°C) and 95% relative humidity. Market quality evaluations were made periodically during storage at both 40° and 50°F. Quality examinations were made at 133, 180, 227, and at storage termina­ tion (258 days). Market quality is a subjective determination. Each tuber is inspected (cut if needed) for dry rot and soft rot (both potential storage dis­ orders) . Disorders not attributable to storage did not disqualify a potato from the marketable catagory (for example, a small hole eaten out by a white grub, the presence of a large scab, or a growth disformed potato were not disqualified from the marketable catagory). Market quality evaluations were divided into the following catagories: 1. Marketable 2. Dry rot 3. Soft rot 0.0 to 5.0% 5.1 to 10.0% 10.1 to 25.0% over 25.0% 0.0 to 5.0% 5.1 to 10.0% 10.1 to 25.0% over 25.0% 4. Miscellaneous (Other reasons like scab, deformity, insect chewing, etc. but not attributable to a storage disorder). Market quality evaluations destroy the sample; therefore, all marketable quality data reported are specifically for the predesignated lot sample only (the sample is not returned to the storage cubicle). Sucrose Ratings: At the time of harvest representative samples of tubers are randomly selected from the five replications and nine treatments. Tubers from the five replications for a given treatment are combined for the sucrose evaluation. Immediately after harvest on August 19, 1980 these bagged samples (1 bag each for the nine treatments) were delivered to Food Science where the sucrose evaluation was supervised by Dr. Jerry Cash. These sucrose ratings will be presented later in this report. DISCUSSION AND RESULTS Production Phase: The nine production management practices used for the 1980 Integrated Project are as follows: Treatment Number 1 2 3 4 5 6 7 8 9 Potassium Rate 0 lbs K2O/A 50 lbs K20/A 150 lbs K20/A 0 lbs K20/A 50 lbs K20/A 150 lbs K20/A 0 lbs K20/A 50 lbs K20/A 150 lbs K20/A Pesticide Check Check Check Temik Temik Temik Terrachlor Super X Terrachlor Super X Terrachlor Super X The objectives of the production phase were to evaluate the interactions of three potassium levels subjected to three pest control measures and their effect on yield, quality and storability of Superior and to monitor nematodes, fungi and insects to determine their effect on yield response to the inputs. Seed pieces were planted on May 12, 1980 in a McBride sandy loam soil at the Montcalm Potato Research Farm in Entrican, Michigan. Each plot consisted of four rows 50 feet long having a 34 inch row width and 8-12 inches between seed pieces. Three levels of potassium 0, 50 and 150 pounds K20/A were subjected to three dif­ ferent pest control treatments: Temik 15G 3.0 lbs. a.i./A, Terrachlor 8.0 lbs. a.i./A, and a check. Each of the nine treatments were replicated five times. A 3x3x5 split factorial design was used. All plots received the standard rate of nitrogen and phosphorus fertilizers. 50 and 150 lbs. per acre of potassium were broadcast prior to planting. Temik 15G was banded with the starter fertilizer at a rate of 3.0 lbs. a.i./A. Terrachlor was broadcast as a granular at 8.0 lbs. a.i./A and disked in. Insects were monitored weekly and sprays were applied when deemed necessary. Soil and root population densities of the root lesion nematode (P. penetrans) were deter­ mined by sampling at planting and every two weeks thereafter. Nutrient levels were monitored by preplant soil samples plus petiole sampling twice during the growing season. The center two rows of each plot were harvested, graded and weighed. Table 1 presents the results obtained by the researcher for the production phase. The range in yield per acre is from 228 cwt/acre (check treatment #1) to 295 cwt/acre (treatment #6). Specific gravity ranged from a low of 1.0664 (treat­ ment #9) to 1.0718 (treatment #8). Sucrose Rating Phase: The sucrose rating at harvest has been discussed as a potential guide for storability. The lower the sucrose rating the higher the stora­ bility potential. Potatoes having a sucrose rating above 2.5 mg sucrose per gram of tuber weight should not be stored for processing potatoes. The sucrose ratings for the 1980 Superior potatoes at harvest were measured and are presented in Table 2. The ratings are all below 2.5 and range from a low of 0.87 mg sucrose/g tuber (treat­ ment #7) to a high of 1.34 (treatment #4). Weight Loss During Storage: Weight loss information for the 1980 Superior potatoes is presented in Tables 3 to 7. The potatoes were harvested and stored at 40° and 50°F (4.5° to 10°C) at 95% relative humidity. They were harvested August 19, 1980 and placed in a 60°F cubicle at 95% RH for 14 days then lowered at 5°F per week to the designated storage temperature. The bagged samples (approxi­ mately 25 lbs. per bag) were weighed at harvest and after suberization. They were also weighed at intervals during storage of 133 days, 180, 227, and at termination (258 days). Tables 3 and 4 show the weight loss (%) for Superior potatoes stored for 258 days at 40°F. Both lots of these potatoes showed excessive sprouting at 258 days due to the fact no sprout inhibitors had been applied. The average loss in Table 3 ranges from 9.4 (treatment #1) to 10.5 (treatment #9) and averages 9.9%. Weight loss from comparable potatoes from the same integrated plots is shown in Table 4. The average loss ranges from 8.4 (treatment #1) to 11.2 (treatment #4). Weight loss is important to a potato grower and storage owner because potatoes are sold by weight. Weight loss is also an indication of processability. Excessive weight loss (above 10%) may present the potato chip processor a problem in main­ taining raw product slice thickness. During the past years of research one goal has been to develop a weight loss factor for various storage periods and environ­ ments. The weight loss factor is "weight loss per day in percent." The WLF in Table 3 for 40°F, 258 days is 0.038% and for equivalent potatoes in Table 4 is 0.037. Table 5 shows the weight loss for Superior potatoes equivalent to the potatoes in Table 4 but scored at 50°F (10°C). The weight loss is excessive at 227 days as shown by the 24.1% average loss. These potatoes were beyond the point for process­ ability. The weight loss factor (WLF) is 0.105 for 50°F, 227 day storage for Superior TABLE 1 Influence of Selected Management Practices on Final Tuber Yield and Specific Gravity of Superior empty table cell 1. 0 lbs K20/A - check 2. 50 lbs K20/A- check 3. 150 lbs K20/A - check 4. 0 lbs K20/A - Temik2 5. 50 lbs K20/a - Temik 6. 150 lbs K20/A - Temik 7. 0 lbs K20/A - Terraclor3 8. 50 lbs K20/A - Terraclor 9. 150 lbs K20/A - Terraclor 1980 Tuber Yields (CWT/A) A 228.24a1 236.84a 234.86a 269.74bc 273.58bc 294.96c 233.30a 242.40ba 241.92ba Tuber Yields (CWT/A) Jumbo Tuber Yields (CWT/A) B Tuber Yields (CWT/A) (A+Jumbo) Specific Gravity 1.06a 1.54a 2.14a 5.54b 8.60C 8.92c 0.94a 1.52a 1.38a 17.68a 15.54a 16.60a 18.16a 15.82a 16.38a 18.44a 15.98a 16.28a 227.62a 238.38a 237.00a 275.28b 282.20b 303.90b 234.24a 243.94a 243.32a 1.0710bc 1.0700abc 1.0696abc 1.0678ab 1.0674ab 1.0672a 1.0692abc 1.0718c 1.0664a 1Treatment means within column followed by the same letter are not significantly different at the .05 probability level based on Student-Newman-Keuls multiple range test. 2(3.0 lbs. a.i./A) 3(8.0 lbs. a.i./A) Table 2. Sucrose ratings at harvest for 1980 Superior potatoes grown in the integrated plots at the MSU Potato Research Farm and harvested August 19, 1980. Production Treatment1 Sucrose Ratings mg Sucrose/g tuber 1 2 3 4 5 6 7 8 9 Average 1.18 1.15 0.93 1.34 1.09 1.06 0.87 1.09 1.15 1.10 1. Refer to page 3 for description of the nine production treatments. Table 3. Weight loss from 1980 Superior potatoes grown on the MSU Potato Research Farm under nine production treatments and stored (for seed viability) in MSU cubicles at 40°F (4.5°C) and 95% relative humidity for 258 days. Production Treatment1 1 2 3 4 5 6 7 8 9 Average Replication IWeight Loss , % Replication Weight Loss, % II 9.2 9.2 9.3 8.5 9.9 9.3 10.7 9.4 9.3 9.4 9.4 9.7 9.0 11.2 9.4 11.5 9.5 9.9 9.7 9.9 Replication IIIWeight Loss, % 9.7 9.6 10.1 10.9 9.4 10.2 10.4 9.9 12.4 10.3 Weight Loss Factor (wt. loss/day, %) 1 Refer to page 3 for description for the production treatments. Average 9.4 9.5 9.5 10.2 9.6 10.3 10.2 9.7 10.5 9.9 0.038 Table 4. Weight loss from 1980 Superior potatoes stored (for weight loss determination) in MSU cubicles at 40°F (4.5°C) and 95% relative humidity for 258 days. Production Treatment1 Replication1 I Weight Loss, % Replication1 II Weight Loss, % Replication1 III Weight Loss, % Average 1 2 3 4 5 6 7 8 9 Average 7.4 8.9 8.4 9.2 8.3 9.2 8.5 8.6 8.3 7.9 9.3 10.2 11.4 9.6 10.1 8.7 9.8 8.7 10.0 8.8 11.9 13.1 11.2 10.4 11.8 9.7 9.6 8.4 9.0 10.2 11.2 9.7 9.9 9.7 9.4 8.9 8.5 9.5 10.7 9.6 Weight Loss Factor (wt. loss/day, %) 0.037 1 Refer to page 3 for description for the nine production treatments and replications for the 1980 Superior potatoes grown in the integrated plots at the MSU Potato Research Farm. Table 5. Weight loss from 1980 Superior potatoes stored for weight loss determination in MSU cubicles at 50°F (10°C) and 95% relative humidity for 227 days. Production Treatment1 50F2 1 50F2 2 50F23 50F24 50F25 50F26 50F27 50F28 50F29 Average Replication1 I Weight Loss, % Replication1 II Weight Loss, % Replication1 III Weight Loss, % 26.4 24.1 25.2 * 24.2 23.9 24.6 23.6 27.9 25.0 23.6 23.0 21.7 24.6 23.5 * 21.3 25.0 24.7 24.7 19.3 23.8 27.3 25.1 24.6 24.8 23.2 21.8 24.6 23.8 Average 22.9 23.2 25.7 24.3 24.4 23.3 24.3 23.4 25.7 24.1 1Refer to page 3 for description for the nine production treatments. Weight Loss Factor (wt. loss/day, %) 0.106 2 Percent weight loss was calculated with sprouts removed due to excessive sprouting. * No data recorded for these samples. Table 6 illustrates the progressive weight loss during storage periods from 133 days to 227 days and compares weight loss at 40° to 50°. Excess sprouting occurred in the 227 day 50°F storage, therefore, growers should not attempt to hold Superior potatoes that are not sprout inhibited at 50°F for periods beyond 200 days. It is interesting to note that the WLF at 133 days at 40° and 50° is very similiar, 0.046 (40°) and 0.047 (50°) and 133 days. The weight loss factor appears to change from one years potatoes to another. The attempt is to store Superior potatoes over enough years that a reliable WLF can be developed. The WLF for 40° and 50°F storage temperature for 133, 180, and 227 days are shown in Table 7. Weight loss factors were calculated for 1979 Superior potatoes stored at 40°. Data from 1979 and 1980 40° storage are compared: Storage Days 118 133 167 180 195 227 233 1979 .039 empty table cell .036 empty table cell .040 empty table cell .041 1980 empty table cell .046 empty table cell .041 empty table cell .037 empty table cell Market Quality: The Superior potatoes grown for the MSU Integrated Project were harvested August 19, 1980 and stored for market quality evaluations. The harvested potatoes were suberized at 60°F 95% RH for 14 days. After suberization temperature was reduced 5°F per week to the designed storage temperature of 40 or 50°F. Bags of Superior potatoes for market quality evaluations, were removed from storage at intervals of 133 days, 181 days, and 258 days. Each individual tuber from a lot was evaluated for quality after the designated storage period. The tuber quality evaluation was determined by Dr. H.S. Potter, MSU Botany and Plant Pathology. Each potato was classified as either marketable, dry rot, soft rot, or miscellaneous. If a tuber was classified "miscellaneous" but the disorder was not storage orientated it could be counted marketable (for example, a potato with white-grub damage but no dry or soft rot would be reclassified as marketable). Under the classification of dry and soft rot there were four degrees of rot (0 to 5%; 5 to 10%; 10 to 25%; and over 25%). These latter degrees of rot are meerly academic because any level of rot should not be classified as marketable. In a 25 pound bagged potato sample marketable quality, in percent, can vary due to method of evaluation of the tuber; whether by tuber weight or number of tubers in the sample. Therefore, for evalua­ tion it is necessary to express market quality in percent good tubers based on weight and numbers of good tubers. Table 6. Influence of storage duration on weight loss from 1980 Superior Potatoes using nine different production treatments and stored at 40°F (4.5°C) and 50°F (10°C) and 95% relative humidity. Production Treatment1 40° 1 40° 2 40° 3 40° 4 40° 5 40° 6 40° 7 40° 8 40° 9 Average Storage period, Days Storage period, Days 180 3 133 2 Weight Loss, % Weight Loss, % Storage period, Days 227 4 Weight Loss, % 5.9 6.4 5.5 6.8 6.1 6.3 6.3 6.2 5.6 6.1 7.3 6.7 6.8 8.0 7.3 7.9 8.0 7.5 6.8 7.4 9.2 8.3 7.8 8.3 8.3 8.8 8.3 8.9 8.1 8.4 Weight Loss Factor 0.046 0.041 0.037 50° 1 50° 2 50° 3 50° 4 50° 5 50° 6 50° 7 50° 8 50° 9 Average 5.2 6.3 6.0 7.1 6.5 6.3 6.8 6.2 6.0 6.3 9.5 9.2 9.6 10.5 10.0 9.8 10.2 9.4 9.5 9.7 23.3 5 23.1 25.2 23.0 23.9 24.3 23.5 22.2 24.2 23.6 Weight Loss Factor 0.047 0.054 0.104 1 Refer to page 3 for description of the nine production treatments. 2 Average weight loss determined from 6 separate bags of approximately 25 lbs. each. 3 Average weight loss determined from 4 separate bags of approximately 25 lbs. each. 4 Average weight loss determined from 2 separate bags of approximately 25 lbs. each. 5 Percent weight loss was determined with sprouts removed due to excessive sprouting from 50°F potatoes stored for 227 days. Table 7. Influence of storage duration on the weight loss factor from 1980 Superior potatoes stored in MSU cubicles at 40°F (4.5°C) and 50°F (10°C) and 95% relative humidity. Temperature Weight Loss Factor, %1 133 days2 Weight Loss Factor, %1180 days 180 days3 Weight Loss Factor, %1 227 days4 40°F 50°F .046 .047 .041 .054 .037 .104 1The weight loss factor is weight loss/day in percent of original weight. 2 The average weight loss factor is determined from 54 sample bags approxi­ mately 25 lbs. each. 3Average weight loss factor from 36 sample bags approximately 25 lbs. each. 4 Average weight loss factor from 18 sample bags approximately 25 lbs. each. ============================================================================ Table 8 presents the market quality, percent good, for two lots of similiar Superior potatoes produced under the nine production management programs and stored at 40°F for 258 days. There appears to be no apparent difference in market quality due to the nine production management programs for the Superior potatoes stored at 40°F and 95% RH for 258 days. Table 9 shows a considerable overall degradation in market quality for pota­ toes stored for 227 days at 50° in contrast to potatoes shown in Table 8 (40°F for 258 days). Average quality reduced from 92.9 to 88.6% (by weight) and 92.7 to 90.4% (by numbers). Again there appears to be no apparent difference in market quality due to the nine production management programs. Table 10 compares 1980 Superior potatoes stored at two temperatures (40° anf 50°F) and three storage durations (133, 181, and 258 days). An analysis of the 40°F lots indicates that the market quality of Superior potatoes can be fairly well maintained by storing bruise-free quality at 40°F. A similiar analysis appears for the 50°F lot. However, the 50°F 258 day figures of 91.3% (weight) and 92.4% (number) do not tell the visual story. Excessive sprouting, weight loss, and shriveling camouflaged the visual observation of storage and market quality degradation. Visual observa­ tion during the market quality evaluation indicated to the author that the average market quality figure of 91.3% (by weight) and 92.4% (by number) are not true indica­ tions of market quality and these data should be disregarded. These figures are presented in Table 10 to illustrate this very point. The comparison in Table 10 between the 40°/50° and 133 days data needs further clarification.- This illustrates an important criteria in potato storage management; it is more important in short term storage to maintain a constant temperature than to rapidly reduce the temperature and be unable to maintain the storage temperature. Potatoes degrade more due to a fluctuating temperature than they do in a slightly higher constant storage temperature. Table 8. Marketable quality of 1980 Superior potatoes grown on the MSU Potato Research Farm under nine production treatments and stored in MSU cubicles at 40°F (4.5°C) and 95% relative humidity for 258 days. Marketable Quality2, % good3 By Tuber Weight Marketable Quality2, % good3 40°F4 5 Production Treatment1 40°F4 1 40°F4 2 40°F4 3 40°F4 4 40°F4 6 40°F4 7 40°F4 8 40°F4 9 Average 40°F5 1 40°F5 2 40°F5 3 40°F5 4 40°F5 6 40°F5 7 40°F5 8 40°F5 9 Average 40°F5 5 94.2 92.3 92.9 87.6 91.1 94.2 93.3 96.6 94.1 92.9 93.4 95.5 96.1 95.8 92.4 95.5 97.1 94.2 95.3 95.0 By Number of Tubers 95.9 90.2 93.1 87.9 91.3 92.5 94.1 96.3 93.2 92.7 93.1 95.6 95.9 95.2 89.7 94.6 96.8 92.3 96.4 94.4 1 Refer to page 3 for description of the nine production treatments. 2 All data is the average of three bags of potatoes. 3 Equivalent to a U.S. grade A designation.4 This lot of Superior potatoes was stored specifically for weight loss determination.5 This lot of Superior potatoes was stored specifically to determine the influence of storage environment and production treatment on seed via­ bility. These potatoes were evaluated for market quality upon removal from storage. Table 9. Marketable quality of 1980 Superior potatoes grown on the MSU Potato Research Farm under nine production treatments and stored in the MSU cubicles at 50°F (10°C) and 95% relative humidity for 227 days. Production Treatment1 50°F4 50°F4 1 50°F4 2 50°F4 3 50°F4 4 5 50°F4 6 50°F4 7 50°F4 8 50°F4 9 Average Marketable Quality2, % good Marketable Quality2, % good3 3 By Tuber Weight By Number of Tubers 90.0 94.1 91.9 82.3 90.2 87.9 80.9 86.6 93.6 88.6 93.9 94.1 94.7 87.5 88.2 88.2 81.7 90.2 95.3 90.4 1 Refer to page 3 for description of the nine production treatments. 2 All data is the average of three sample bags. 3 Equivalent to a grade A designation. 4 This lot of potatoes was stored specifically for weight loss determina­ tions. Table 10. Marketable quality of 1980 Superior potatoes grown on the MSU Potato Research Farm under nine production treatments and stored at two environmental conditions, 40° and 50°F (4.5° and 10°C) and 95% relative humidity, and three different storage durations. 133By Tuber WeightMarketable Quality2 , % good3Storage Duration, days 133 Marketable Quality 2 , % good 3Storage Duration, days By Number of Tubers Marketable Quality2 , % good3 Storage Duration, days 18 1 By Tuber Weight Marketable Quality2 , % good3 Storage Duration, days 18 1 By Number of Tubers Marketable Quality2 , % good3Storage Duration, days 258By Tuber Weight Marketable Quality2 , % good3Storage Duration, days 258 By Numberof Tubers 92.7 90.9 98.2 95.5 91.8 93.2 96.3 96.5 92.9 94.2 94.0 93.2 98.5 96.6 93.3 93.8 96.9 96.4 93.4 95.1 94.2 94.6 96.2 94.0 90.8 91.6 93.2 95.1 94.1 93.8 94.9 95.8 97.4 91.9 95.4 92.3 93.8 96.1 94.5 94.7 93.9 93.3 94.4 96.6 96.0 95.1 96.1 96.1 96.9 95.4 Production Treatment1 and Storage Temp. 40°F (4.5°C) 1 40°F (4.5°C) 2 3 40°F (4.5°C) 4 40°F (4.5°C) 40°F (4.5°C) 5 6 40°F (4.5°C) 40°F (4.5°C) 7 40°F (4.5°C) 8 40°F (4.5°C) 9 Average 50°F (10°C) 1 50°F (10°C) 2 3 50°F (10°C) 50°F (10°C) 4 50°F (10°C) 5 6 50°F (10°C) 50°F (10°C) 7 8 50°F (10°C) 50°F (10°C) 9 94.1 93.1 96.2 97.7 96.2 95.8 95.9 95.9 97.3 95.8 92.1 94.4 89.2 87.9 89.2 92.5 95.8 95.5 94.8 92.4 96.4 98.2 97.6 93.1 93.8 98.0 99.0 97.6 99.6 97.0 96.6 97.4 98.2 94.1 96.5 97.4 99.0 98.2 99.0 97.4 95.9 88.6 86.8 82.9 85.3 88.3 90.0 89.1 88.8 88.4 94.8 86.4 86.6 80.7 86.8 89.1 87.8 88.0 87.4 87.5 90.4 88.6 90.0 85.6 89.0 92.4 96.2 94.0 95.9 91.3 Average 1 Refer to page for description of the nine production treatments. 2 All data is the average of two sample bags. 3 Equivalent to a grade A designation. An important storage management point is that growers strive to lower pulp temperature too rapidly in their fall storage procedure. The recommended storage management procedure is to slowly and continuely lower the storage temperature at a rate that can always be maintained. Fluctuating storage temperatures degrade the storage life of a potato. Seed Viability Phase: Random samples of 1980 Intergrated Project Superior potatoes were selected from each of nine production management practice lots and stored at 40°F and 95% RH specifically for a seed viability check. The objective was to observe if any of the nine production management treatments influenced seed viability. Storage variability was eliminated as a variable due to the fact pota­ toes from all nine treatments were stored in the same environment, and planted and grown under one 1981 production management treatment. Table 11 shows the results of the 1980 potatoes grown during 1981 at the MSU Potato Research Farm. Total yield ranges from 309 cwt/acre (treatment #5) to 382 cwt/acre (treatment #8). The yield of No. 1 potatoes ranged from 287 (#5) to 356 (#6). The nine production treatments do not appear to influence seed viability. Table 11. Superior potatoes grown under the nine production management practices of the 1980 MSU Integrated Project were harvested and stored for 258 days at 40°F (4.5°C) and 95% RH. These potatoes were planted in 1981 for a seed viability analysis.1 Treatment No. Total cwt/A No. 1 cwt/A Percent Size Distribution Percent Size Distribution Percent Size Distribution Pick outs Over 3 1/4" Under 2" Percent Size Distribution 2- 3 1/4 1 2 3 4 5 6 7 8 9 354 346 346 359 309 381 371 382 368 324 315 314 326 287 356 346 348 332 7.9 8.6 8.1 7.8 6.6 6.1 6.7 8.6 8.5 0.5 0.5 1.3 1.3 0.5 0.5 0 0.2 1.2 0 1.3 2.3 1.3 0 1.2 1.7 1.2 3.4 91.6 89.6 88.3 89.6 92.9 92.2 91.6 90.0 86.9 Superior - cut seed Planted: May 8, 1981 Harvested: September 15, 1981 1Seed pieces from each of the nine treatments were planted in one plot where all plants received one recommended production management practice during the 1981 season. ALCOHOL PRODUCTION FROM POTATO PROCESSING WASTES C.A. Reddy and M.A. Abouzeid Departments of Microbiology and Public Health INTRODUCTION Lare volumes of wastes are generated at various stages during the pro­ cessing of potatoes. The quantities of solids in the waste streams vary significantly depending on the product being manufactured and the quality of the raw potato. The magnitude of product solids are highest in waste streams from peeling, trimming and cutting. It has been estimated that the potato processing industry as a whole generates about four billion kg of wastes annually in the U.S.A. This large volume of wastes represents a costly disposal problem and a wastage of enormous quantities of starch. Utilization of potato processing wastes for alcohol production would elimi­ nate the costly disposal problem and would potentially yield 130 million gallons of alcohol per annum. Thus, the potato processing wastes, if prop­ erly utilized, could bring an economic boon to potato processing plants in the state. Little is known about the fermentation of potato wastes to alcohol. However, theoretical calculations indicated that 25 gallons of alcohol per ton of potatoes could be produced. Preliminary analyses by Dr. Heldman at MSU showed that up to 0.7 gallons of ethanol could be expected from potato processing waste streams from every 220 lbs of raw potatoes entering the processing plant; however, this appears to be a conservative estimate. The objective of our present investigation was to develop relatively simple and efficient fermentation procedures for the production of alcohol from potato processing wastes. METHODS Potato starch used in this investigation was recovered from waste stream generated by Allied Foods potato chip manufacturing plant located in Livonia, Michigan. This substrate is here after referred to as PPW and contained 98.6% (w/w) carbohydrate. Unless otherwise mentioned, fermenta­ tions were conducted in one liter flasks in a sterile medium containing PPW, peptone (0.1%) and minerals. All fermentations were conducted at 30°C at pH 5.5. Flasks were inoculated with different yeasts, fungi or a syn­ ergistic combination of both as described in results. Inoculum level was 5%(v/v) unless mentioned otherwise. Fermentation samples were collected at specified intervals and were analyzed for reducing sugar, total carbohydrate, ethyl alcohol, amylolytic activity and cell yield (dry weight). RESULTS In most existing processes for the production of alcohol from starchy feeds (such as corn) the starch is initially hydrolyzed to glucose by a two step enzymatic process using industrial starch digesting enzymes. Hence, this procedure was used to hydrolyze the starch in PPW and the glucose obtained was fermented with six most promising strains of saccharomyces species. The results of this study showed that Saccharomyces cerevisiae, strain ATCC 26603, was the most desirable organism in that it fermented the PPW-derived glucose to ethanol with about 80% efficiency. Hence, this par­ ticular strain was used in all later fermentations. Optimization of the fermentation of enzymatically hydrolyzed PPW to alcohol is currently being investigated by a team headed br Dr. Jerry Cash of the Department of Food Science at MSU. In an effort to increase the efficiency and economy of the overall fermentation, we directed our efforts at this stage to eliminating the enzymatic hydrolysis step and to accomplish direct fermentation of PPW to alcohol. To achieve this objective, we used a synergistic mixture of a starch-digesting yeast or fungus which hydrolyzes starch in PPW to glucose, and a second organism which ferments the glucose to alcohol. The results presented in Table 1 showed that starch utilization by Aspergillus niger (a starch digester) alone or that by A. niger plus S. cerevisiae combination was comparable but ethanol production was substan­ tially higher by the mixed culture. A. niger in pure culture produced only small amounts of ethanol but substantially larger amounts of cell mass compared to the mixed culture. Further cell mass and ethanol production were roughly proportional to the PPW concentration. These results clearly indicated that the basic idea of using synergistic mixed culture for the direct fermentation of PPW is a viable one, but the yields were relatively low (60%). Hence, a large number of combinations of a starch digesting fungus or yeast plus Saccharomyces cerevisiae were examined to identify the most efficient combination for the fermentation. The results shown in Table II indicated that aspergillus strains in pure culture consistently produced small amounts of ethanol and showed relatively low amylolytic activity, whereas Aspergillus plus Saccharomyces combinations consistently showed greater ethanol production, lower residual carbohydrate and higher amylolytic activity. Rhizopus in pure culture produced respectable amounts of ethanol; little improvement was seen when this organism was grown with saccharomyces. Lipomyces and S. fibuligera gave substantially higher yields of ethanol than when they were grown in pure culture. Based on the results of this experiment, A. niger was selected for further study. The results presented in Table II showed that the low amylolytic activity observed in pure cultures of Aspergillus coincided with higher residual carbohydrate concentrations in these cultures. These results suggested that the amylolytic activity is being inhibited by the sugar accumulating in these fermentations. To see if this was true, A. niger was grown alone and in mixed culture with S. cerevisiae in 1% PPW and 5% PPW medium (Table III). One would expect less accumulation of sugar and little inhibition of amylolytic activity in 1% PPW medium, whereas in 5% PPW medium one would expect substantial accumulation of sugar and severe inhibition of amylolytic activity. As expected, severe inhibition of amylolytic activity was seen in A. niger pure culture in 5% PPW medium, in the same medium little inhibition of amylolytic activity was seen when A. niger and S. cerevisiae mixed culture was grown. These results clearly indicated that PPW-derived sugar inhibits starch digestion by A. niger. Therefore, it appeared that one may be able to improve this fermentation by increasing the level of yeast inoculum and thus keeping the glucose concentration rel­ atively low. These experiments are in progress. The results presented in Table IV showed that aeration has a profound effect on ethanol yield. The culture in flasks with no aeration gave ethanol yields up to 70% of the theoretical which was considerably higher than that observed in aerated flasks. Further studies are currently in progress to optimize the level of inoculum of A. niger and S. cerevisiae, to optimize the pH, concentration of PPW, temperature and other important process parometers. CONCLUSIONS 1. 2. Enzymatically hydrolyzed potato processing wastes can be fermented to alcohol with about 80% efficiency. A synergistic mixture of A. niger, a starch digester, and S. cerevisiae, a nonanylolytic sugar fermenter, could be employed for the direct fermentation of unhydrolyzed PPW to alcohol. A fermentation efficiency of 70% has been achieved to date. Table 1. Effect of PPW Concentration on Ethanol Produ * ction PPW (g/100 ml) A. niger Starch used g/100 ml A. niger Cells A. niger EtOH g/100 ml A. niger + S. cerevisiae Starch used g/100 ml A. niger + S. cerevisiae Cells A. niger + S. cerevisiae EtOH g/100 ml 1 2 3 4 5 0.9 1.9 2.5 3.7 4.2 1.0 1.5 1.8 2.1 2.7 0.17 0.17 0.29 0.29 0.30 0.96 0.96 2.9 3.8 4.8 0.9 1.0 1.1 1.4 1.6 0.18 0.48 0.70 1.03 1.33 Limited aerobic conditions; pH 5.5; temperature 30°C; incubation time 7 days Table 2. Production of Ethanol from PPW (5%) by Certain Amylolytic Fungi in Pure Culture and in Mixed Culture with S. cerevisiae* Organism S. cerevisiae Ethanol (g/100 ml) Residual (g/100 ml) Amylolytic Activity (μ/ml) A. niger A. niger A. foetidus A. foetidus A. awamori A. awamori Rhizopus sp. Rhizopus sp. Lipomyces kononenkoae Lipomyces kononenkoae S. fibuligera S. fibuligera - + - + - + - + - + - + 0.27 1.21 0.40 0.71 0.23 0.87 1.03 1.03 0.24 1.27 0.45 1.15 0.92 0.10 1.76 0.81 2.0 0.54 0.14 0.42 1.06 0.32 0.23 0.17 4.4 10.6 - 10.6 - 10.0 8.8 7.4 8.9 8.8 2.5 10.6 *Time of incubation is 5 days; temperature 30°C; pH 5.5. Table 3. Correlation Between Sugar Concentration in the Culture Filtrate and the Amylolytic Activity Observed 1% 1% PPW 5% PPW 5% Days 1% PPWA. niger A. niger PPW A. niger + S. cerevisiae 1% PPWA. niger + S. cerevisiae 5% PPWA. niger A. niger PPW A. niger + S. 5% PPW A. niger + S. cerevisiae Sugar (mg/ml) AA* (U/ml) Sugar (mg/ml) AA* (U/ml) Sugar (mg/ml) AA* (U/ml) cerevisiae Sugar (mg/ml) AA* (U/ml) 1 3 5 7 9 12 6.0 7.2 5.2 0.7 0.6 0.5 5.0 7.8 8.3 11.7 11.7 11.4 2.8 1.5 0.9 0.6 0.5 0.5 8.3 10.0 12.8 11.7 12.8 11.1 5.3 17.4 18.0 18.6 20.4 17.8 6.1 - - - - - 3.0 12.2 8.6 3.0 1.0 1.0 6.6 - 7.8 8.3 12.2 10.9 *AA = amylolytic activity. 1 unit = μmole glucose liberated/3 min/ml of culture. Table 4 Effect of Different Aeration Conditions Treatment Starch Utilized Air Limited air No air N2a 4.8 4.6 4.7 - Ethanol (g/100 ml) Cells 0.78 1.35 1.59 1.59 1.43 0.90 0.77 0.93 aAspergillus niger was grown aerobically for 24 hr followed by flushing under N2. CORN HYBRIDS, PLANT POPULATION AND IRRIGATION E.C. Rossman and Keith Dysinger Department of Crop and Soil Sciences Performance data for 90 commercial corn hybrids evaluated in 1981 with and without irrigation are presented in Table 1 along with two and three year aver­ ages for those tested in 1980 and 1979. Bouyoucous soil moisture blocks were placed at 6, 12, 18 and 24 inch depths in both irrigated and unirrigated plot areas. Irrigation was applied when soil moisture reached 50% or less of water holding capacity at 6" level. Four inches of supplemental water was applied during July and August. Irrigated yields averaged 28.0 bushels more than nonirrigated—115.4 vs. 87.4, an increase of 32%. Hybrids ranged from 85.0 to 140.6 bushels per acre with irrigation and 62.2 to 111.4 without irrigation. Hybrids significantly better than average yield (arranged in order of increasing grain moisture con­ tent at harvest) are listed below. Sixteen of the 21 hybrids were in the high­ est yielding group for both irrigated and nonirrigated plots. Irrigated Pioneer 3901 (2X) Pioneer 3906 (2X) Amcorn ZX5500 (2X) Diaryland DX1004 (2X) Great Lakes GL-455 (2X) Pride 4461 (2X) Pioneer 3744 (2X) Super Crost 2350 (2X) Great Lakes GL-477 (2X) Great Lakes GL-522 (2X) McKenzie 409 (2X) Super Crost 2410 (2X) Super Crost 2396 (2X) Payco SX788 (2X) Stauffer Seeds B606 (2X) Migro M-2018X (2X) Custom CFS6007 (2X) Custom CFS W4000 (2X) Not Irrigated Pioneer 3901 (2X) Dairyland DX1096 (2X) Pioneer 3906 (2X) Amcorn ZX5500 (2X) Dairyland DX1004 (2X) Great Lakes GL-455 (2X) Pride 4461 (2X) Pioneer 3744 (2X) Dairyland DX1003 (2X) SuperCrost 2350 (2X) Great Lakes GL-477 (2X) Great Lakes GL-522 (2X) Super Crost 2410 (2X) Super Crost 2396 (2X) Payco SX788 (2X) Stauffer Seeds B606 (2X) DeKalb XL32A (2X) Migro M-2018X (2X) Custom CFS6007 (2X) The correlation of irrigated with unirrigated yields was highly signifi­ cant, .794, indicating that the hybrids tended to respond alike in both situ­ ations. During the 14-year period, 1968-1981, the correlations have ranged between .7 and .9 except for 1976 when it was .490. All correlations have been highly significant. Average, highest and lowest yields for corn hybrids irrigated and not ir­ rigated for the 14-year period, 1968-1981, are given in Table 2. The average yielding hybrids have yielded 44 more bushels when irrigated. The highest yielding hybrids have responded with 57 bushels added yield while the lowest yielding hybrids have given only 27 bushels added yield when irrigated. These results demonstrate the importance of choosing high yielding hybrids to maxim­ ize returns from irrigation with little, if any, additional cost. There was a trend toward more stalk lodging without irrigation, 5.9% vs. 8.6% (Table 1) but not for all hybrids. In most (but not all) of the previous years, there was less lodging on the irrigated plots. Generally, stressed weaker plants on unirrigated plots have been more susceptible to lodging. In 1981, the highest lodging was 17.8% stalk breakage when irrigated compared to 36.7% when unirrigated. PLANT POPULATION X HYBRIDS Five adapted hybrids at four plant populations irrigated and not irrigated have been grown in each of 14 years, 1968-1981, Table 3. Over the 14-year period, a harvest plant population of 23,300 has given the highest average yield (164 bushels per acre) when irrigated while 19,300 has given the highest yield (109 bushels) without irrigation. The 23,300 population irrigated has given the highest yield in 11 out of 14 years (1973, 1979 and 1981 being the exceptions). The yields in 1981 were 122, 132, 130 and 119 bushels per acre for harvest populations of 15,300, 19,400, 23,100 and 27,200, respectively. The difference 132 vs. 130 was not significant; the other differences were significant. The 14-year average increase due to irrigation has been 64 bushels per acre at the 23,300 population. Stalk lodging has increased with increased plant population. In 1981, there was 3-4 times more lodging at 27,200 than there was at 15,300. Moisture content of grain at harvest has averaged .5 - 1.0% higher for the higher populations. Hybrid (Brand Variety) NORTH CENTRAL MICHIGAN Montcalm County Trial - Irrigated vs. Not Irrigated One, Two, Three Year Averages - 1981, 1980, 1979 Bushels Per Acre 2 Years Not Irrig % Moisture Bushels Per Acre 3 1981 yrs. Irrig Bushels Per Acre 3 Years Irrig Bushels Per Acre 1981 Not Irrig Bushels Per Acre 2 years Irrig % Moisture 2 yrs. % Moisture 1981 Bushels Per Acre % Stalk 3 Years Lodging 1981 Not Irrig Irrig % Stalk Lodging 2 Years Irrig Zone 3 -- -- -- % Stalk % Stalk % Stalk Lodging Lodging Lodging 3 Years 2 Years 3 Years Not Irrig Not Irrig Irrig -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 14 -- -- 5 -- -- -- 14 10 20 -- 10 -- -- -- -- 5 -- 7 16 5 -- -- -- -- -- -- -- -- -- 17 13 9 16 18 15 21 10 11 14 7 8 -- -- -- -- -- -- -- 9 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 7 -- 11 14 -- 9 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 10 9 -- -- -- -- -- 15 -- -- -- -- -- -- -- -- 7 -- -- -- -- -- 14 -- -- -- -- -- -- -- -- 7 7 5 (continued) McKenzie 858 (2X) Asgrow RX355 (3X) Stauffer Seeds S2202 (2X) Great Lakes 81201 (2X) P.A.G. SX157 (2X) Stauffer Seeds S3306 (2X) Migro HP-201 (2X) Wolverine W126 (2X) Great Lakes GL-422 (2X) Warwick W901 (2X) Garno S-88 (2X) Garno S-85X (2X) DeKalb XL14AA (2X) Migro M-0101 (2X) Garno S-86 (2X) Great Lakes GL-456 (2X) +*Pioneer 3901 (2X) Hyland HL-2456 (2X) DeKalb XL13 (2X) Payco SX637 (2X) Pioneer 3958 (2X) +Dairyland DX1096 (2X) Garno S-90 (2X) Pride 3332 (2X) Gutwein 2085 (2X) -- 20.2 20.7 -- 21.2 -- -- 21.5 21.6 -- 21.8 -- -- 21.8 23 21.9 23 22.0 22.1 22 -- 22.1 -- 22.3 22.3 23 23 22.3 -- 22.4 -- 22.5 23 22.5 -- 22.5 22.6 -- 22.7 -- 22.8 23 22.8 23 23 22.9 23.0 -- -- 23.0 +*Pioneer 3906 (2X) McKenzie 927 (MSX) Ancorn PSX3100 (2X) Custom CFS 1450 (2X) Payco SX619 (2X) +*Amcorn ZX5500 (2X) +*Dairyland DX1004 (2X) Garno S-92 (2X) Migro HP-277 (2X) +*Great Lakes GL-455 (2X) Funk G-4256 (3X) Stauffer Seeds S4402 (2X) Great Lakes GL-466 (2X) P.A.G. SX18 (2X) Pioneer 3780 (2X) Gutwein 2210 (2X) Garno S-95Y (2X) +*Pride 4461 (2X) Payco SX620 (2X) Wolverine W166 (2X) Dairyland DX1099 (2X) +*Pioneer 3744 (2X) Pickseed 6688 (2X) Payco SX611 (2X) DeKalb EX1213 (2X) Trojan T950 (2X) Stauffer Seeds S4800 (2X) +Dairyland DX1003 (2X) Garno S-94E (2X) +*Super Crost 2350 (2X) 23.2 23.2 23.1 23.1 23.1 23.2 23.2 23.2 23.3 23.4 23.5 23.6 23.6 23.7 23.7 23.8 23.8 23.8 23.9 24.0 24.0 24.0 24.0 24.1 24.1 24.1 24.1 24.1 24.4 24.7 -- -- -- -- -- -- -- 24 24 -- -- 24 24 -- -- 25 25 -- -- -- -- 24 25 -- -- -- -- -- -- 25 -- 25 -- -- -- -- -- -- -- -- -- -- -- -- -- 23 -- -- 23 -- -- -- 24 -- 23 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 25 -- -- -- -- -- 25 -- -- -- -- -- -- -- -- 25 -- 141 118 -- -- -- -- -- -- -- -- -- 125 109 111 91 -- -- -- -- 82 106 86 102 128 108 74.8 -- 68.6 -- 64.8 -- 65.1 -- 102.6 103.4 92.8 87.5 98.1 66.9 118.7 91.2 86.6 125.1 108.2 105.3 107.2 118.8 103.8 94.9 111.8 128.9 104.6 102.7 114.1 -- 95.1 -- 70.3 -- 64.5 95.0 80.1 73.3 -- 84.1 -- 91.5 77.0 70.1 -- 87.7 -- 97.0 81.8 -- 62.2 -- 89.6 -- 69.0 101.4 122.1 100.5 120.3 93.3 77.4 -- 90.1 92.6 -- 114.2 97.6 -- 68.8 -- 90.2 -- 88.5 -- -- 81.5 136 111 97.7 138.9 111.4 136 117 110.3 114.4 127.9 114.2 122.6 118.0 124.4 119.5 130.4 88.8 119.1 114.5 -- -- -- -- -- -- -- 140 109 101 130 122 116 91 83 117 107 128 130 107 111 -- -- -- -- 77.7 -- 82.4 -- 97.6 87.6 84.9 -- 83.8 -- 93.7 90.6 94.8 -- 113.1 89.0 -- 123.7 129.7 97.9 -- 92.7 -- 121.6 91.6 110.7 76.5 115.9 129.0 107.8 -- 73.6 -- 85.0 125.4 88.2 -- 85.7 -- 103.8 68.4 -- 95.6 90.2 -- 113.2 122.8 99.1 91.6 -- 116.1 140.6 100.6 -- -- -- -- -- -- -- -- -- -- -- 113 84 110 119 126 111 125 141 98.2 132.8 -- -- -- -- -- -- -- -- -- -- -- -- -- 107 -- -- 139 104 -- 122 -- -- -- -- 127 -- 109 -- 136 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 82 -- -- 110 -- -- -- 80 -- 102 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 104 -- -- -- -- -- 78 -- -- -- -- -- -- -- -- 104 1.5 16.8 6.2 7.7 7.3 2.9 9.8 17.8 5.2 10.5 6.8 12.2 6.3 7.8 4.1 7.5 0.7 9.4 16.3 5.8 7.9 11.3 3.0 15.8 5.1 7.4 6.3 2.3 6.4 5.8 3.3 5.9 2.9 2.1 8.6 1.5 5.0 2.5 3.8 5.1 5.3 8.1 1.8 7.1 5.8 3.6 3.1 13.5 4.3 8.9 4.1 2.8 6.9 7.5 4.5 % Stalk Lodging 1981 Not Irrig 3.3 -- 15.9 -- 12.3 -- 10.9 -- 19.4 -- 4.9 -- 5.2 -- 13 19.3 8 3.9 16.0 14 1.8 -- 13.2 -- 7.2 9 19.0 10 5.8 -- 13.8 -- 2.0 5 -- 8.1 36.7 -- 7.7 -- 7 19.9 14.4 11 3.8 10 15.4 -- 8.0 -- 6.6 -- 5.8 -- 5.1 -- 5.5 -- -- 9 7.0 5.6 14 12.7 12.2 -- 1.1 -- 14 12.9 12 10.0 12.0 -- 9.0 -- 13 17.8 6 11.8 11.4 -- 11.5 -- 7.0 -- 3.3 -- 6 11.4 11.6 10 4.7 -- 16.1 -- 10.2 -- 8.7 -- 3.0 -- 5.3 -- 3.7 8.8 -- 11.0 TABLE 1. (Continued) Hybrid (Brand-Variety) % Moisture Bushels Per Acre % Moisture 3 1981 1981 yrs. Irrig % Moisture 2 yrs. Bushels Per Acre 1981 Not Irrig Bushels Per Acre 2 Years Irrig Bushels Per Acre 2 Years Not Irrig Bushels Per Acre 3 Years Irrig Bushels Per Acre % Stalk 3 Years Lodging 1981 Not Irrig Irrig Custom CFS 4004 (2X) DeKalb XL23 (2X) Stauffer Seeds B507 (2X) +*Great Lakes GL-477 (2X) Funk G-4224 (MSX) Kaltenberg KX54A (2X) Pickseed 6655 (2X) Pride 4488 (2X) Gutwein 2190 (2X) Payco SX756 (2X) +*Great Lakes GL-522 (2X) Stauffer Seeds S5602 (2X) Payco SX844 (2X) *McKenzie 409 (2X) Hyland HL-2454 (2X) Garno S-99 (2X) Kaltenberg KX55 (2X) Migro HP-23R (2X) +*Super Crost 2410 (2X) Custom CFS W3610 (2X) 24.7 -- 24.8 27 24.8 26 24.8 25 24.9 25 24.9 -- -- 24.9 25.2 26 25.2 -- 25.5 -- 25.6 -- 25.7 -- 25.8 -- 25.9 -- 26.0 -- 26.1 -- 26.3 -- 26.3 27 26.4 -- 26.5 -- +*Super Crost 2396 (2X) +*Payco SX788 (2X) 26.5 27 26.5 -- -- 26.7 Gutwein 2180 (2X) Golden Harvest Exp.436 (2X) 27.0 -- 27.2 -- Trojan T1000 (2X) 27 27.3 27.9 -- 28.1 -- 28.1 29 28.1 -- 28.2 -- -- 28.4 -- 29.1 -- -- 29.3 -- 32.3 -- -- +*Stauffer Seeds B606 (2X) Kaltenberg KX68 (2X) +DeKalb XL32A (2X) +*Migro M-2018X (2X) +*Custom CFS 6007 (2X) Stauffer Seeds S5260 (2X) Migro HP-360 (2X) Amcorn PSX7480 (2X) *Custom CFS W4000 (2X) Payco SX860 (2X) Average Range -- 27 26 -- 25 -- -- 27 -- -- -- -- -- -- -- -- -- 27 -- -- -- -- -- -- -- 28 -- -- 29 -- -- -- 135 94.9 -- 93.1 121.1 125 115.1 116.0 95.0 130 132.0 99.0 143 110.6 89.0 110 91.8 -- 119.8 70.4 -- 102.4 122.4 89.5 74.4 -- 99.4 74.5 -- 99.4 128.8 102.4 -- 122.5 88.8 -- 83.9 -- 125.2 93.6 -- 128.3 119.4 86.4 -- 108.6 87.8 -- 117.0 83.9 -- 110.8 86.6 130 98.2 -- 130.6 92.6 -- 124.4 132 150 145 130.9 101.6 131.8 101.4 -- 85.7 -- 107.5 113.3 89.4 -- 89.6 -- 122.1 134.8 105.2 95.9 -- 126.2 125.0 97.0 -- 134.0 107.9 128.2 108.7 -- 84.7 -- 107.2 101.7 80.1 -- 95.2 -- 122.7 128.0 95.6 -- 90.5 -- 113.7 -- 108 113 122 96 114 108 108 128 124 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 124 129 -- 110 134 125 -- 147 140 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 96 101 -- 84 -- -- 101 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 93 114 111 -- -- -- -- -- -- -- -- % Stalk Lodging 1981 Not Irrig 9.2 -- % Stalk Lodging 2 Years Irrig % Stalk % Stalk Lodging Lodging 3 Years 2 Years Not Irrig Irrig -- -- % Stalk Lodging 3 Years Not Irrig -- 10 9 -- 13 5 9 4.5 2.4 10.6 9.6 7.5 10.8 4.6 8 3.7 11 8 6.3 13 1.5 -- 3.2 7.6 -- 4.8 3.6 1.9 10.3 12.9 -- 5.2 -- 4.3 2.4 -- 0.8 3.6 11.6 -- 5.6 -- 2.4 4.2 13.3 -- 9.9 -- 8.7 2.4 -- 3.4 6.9 -- 8.4 1.7 3.6 4.1 -- 6.9 4.3 17.3 -- 3.8 8.5 13.1 -- 9.3 -- 7.5 5.3 -- 8.5 9.1 -- 4.5 2.4 0.8 -- 5.6 -- 1.5 0.0 -- 5.1 -- 2.0 8.3 -- 2.6 9.1 20.5 -- 6.8 -- 3.1 1.5 6.9 -- 6.8 4.6 3.9 3.1 3.1 9.7 8 4 8 12 9 11 14 2 6 12 6 5 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 7 11 -- 10 10 -- 6 5 -- -- 4 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 1 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 6 4 4 -- -- -- -- -- -- -- -- 24.5 25 20.2 to 32.3 22 to 29 25 23 to 29 115.4 87.4 127 107 124 96 5.9 8.6 9 11 85.0 to 140.6 62.2 to 111.4 101 to 150 82 to 128 104 to 147 78 to 114 0.7 to 17.8 0.0 to 36.7 4 to 14 2 to 21 8 4 to 15 8 1 to 14 (continued) TABLE 1. (Continued) Hybrid (Brand-Variety) least Significant Difference % Moisture 1981 % Moisture 2 yrs. % Moisture 3 yrs. Bushels Per Acre 1981 Irrig Bushels Per Acre 1981 Not Irrig Bushels Per Acre 2 Years Irrig Bushels Bushels Per Per Acre Acre 2 Years 3 Years Irrig Not Irrig Bushels Per Acre 3 Years Not Irrig % Stalk Lodging 1981 Irrig % Stalk Lodgin g 1981 Not Irrig -- -- 1.6 1.0 0.7 12.3 9.3 9 7 6 5 % Stalk Lodging 2 Years Irrig -- % Stalk Lodgin g 2 Years Not Irrig -- % Stalk Lodging 3 Years Irrig -- % Stalk Lodging 3Years Not Irrig -- 1981 May 2 November 6 Montcalm-McBride sandy *Significantly better than average yield, irrigated, in 1981. +Significantly better than average yield, not irrigated, in 1981. empty table cell Planted Harvested Soil Type Previous Crop Population Rows Fertilizer Irrigation Soil Type: pH P Soil Type: K Soil Type: loam Alfalfa 20,850 30” 323-143-143 4 inches 5.9 512 (very high) 284 (high) 1980 May 12 November 11 Montcalm-McBride sandy loam Alfalfa 20,700 30” 315-155-155 3 inches 6.9 528 (very high) 290 (high) Farm Cooperator: Theron Comden, Montcalm Experimental Farm, Lakeview County Extension Director: James Crosby, Stanton 1979 May 19 November 19 Montcalm-McBride sandy loam Alfalfa 20,800 30” 213-80-80 6 inches 5.4 493 (very high) 336 (very high) Table 2. Average, highest and lowest yields for corn hybrids irrigated and not irrigated for 14 years, 1968-1981. Year No. of Hybrids Tested Average Irrigated Average Not Irrigated Highest Irrigated Highest Not Irrigated Lowest Irrigated Lowest Not Irrigated 1981 1980 1979 1978 1977 1976 1975 1974 1973 1972 1971 1970 1969 1968 90 71 83 73 74 80 75 76 72 72 56 64 63 56 empty table cell AVERAGE 115 126 109 144 125 156 154 112 114 157 163 144 146 136 136 87 114 67 88 73 72 125 103 101 137 28 103 86 96 92 141 167 142 186 158 183 207 134 138 206 211 194 185 182 174 111 156 92 112 88 93 157 122 120 179 42 128 109 123 117 85 74 67 92 89 120 106 65 78 99 91 95 97 92 90 62 65 42 61 56 49 80 58 73 91 11 70 56 65 59 Table 3. Average yield at four plant populations irrigated and not irrigated for 14 years, 1968-1981. Year 15,200 Irrigated 15,200 Not Irrigated 19,300 Irrigated 19,300 Not Irrigated 23,300 Irrigated 23,300 Not Irrigated 27,400 Irrigated 27,400 Not Irrigated 1981 1980 1979 1978 1977 1976 1975 1974 1973 1972 1971 1970 1969 1968 122 133 123 146 141 153 158 118 108 152 173 122 126 144 AVERAGE138 93 123 77 92 74 72 136 100 97 132 37 91 91 114 96 132 146 140 164 152 174 183 130 134 187 189 144 158 169 157 102 135 87 110 81 84 164 111 116 159 35 112 109 130 109 130 150 138 175 160 181 196 135 128 191 191 158 173 193 164 94 131 83 100 70 81 151 98 106 149 20 93 96 107 100 119 141 131 165 150 161 172 120 108 161 181 151 148 178 149 86 124 78 94 69 68 146 94 102 144 11 85 86 89 92 COLORED BEAN VARIETY AND STRAIN TESTING--1981 M.W. Adams, A. Ghaderi, J. Kelly, J. Taylor, N. Glandon Department of Crop and Soil Sciences Department of Botany and Plant Pathology and USDA-ARS A.W. Saettler The field was planted on June 4. Fertilization consisted of 240 pounds per acre of 14-37-0 plus 5% Mn and 2% Zn. A tank mix of Eptam, Treflan and Amiben was pre-plant incorporated. Ten pounds/acre of Temik was also applied at planting. Four different experiments were planted: Expt. I. This consisted of 512 entries in 16-foot long single row plots of lines of various seed classes received by Dr. A.W. Saettler from the USDA-ARS program at Prosser, Washington, which were to be evaluated for halo-blight reaction. Dr. Saettler inoculated this test twice with Psuedomonas phaseolicola but the disease did not develop satisfactorily so he did not obtain the desired data. Expt. II. This test consisted of 70 selections in the F3 generation of the Montcalm x Charlevoix cross, which was made to recombine the better test weight of Charlevoix with the halo-blight resistance of Montcalm. Some 38 selections were retrieved from this experiment in Fall 1981, with emphasis in field selection being placed upon visual appearance of plant and seed. In addition, we had 18 miscellaneous entries of kidneys, whites and cranberry beans, to make a total of 88 rows in all. Among the cranberry entries, one row (row #41, entry F706) produced seed of unusual color quality--the seed had not undergone the typical after-ripening browning reaction of most cranberry beans. This entry will be watched closely in 1982. Expt. III. This planting consisted of early generation material (kidney and blacks) being screened by Dr. A. Ghaderi for anthracnose and halo blight resistance. A seed advance was secured on this material. Expt. IV. This test (#1227) consisted of 18 entries of kidney and cranberry beans in 4-row, 4-replicate plots. Table 1 gives days to flowering and yield in pounds/acre of these lines. Table 1. Days planting to 50% flowering and seed yield of commercial varieties and experimental strains of kidney beans (red and white) and cranberry beans at the Montcalm County Research Farm, 1981. Days planting to 50% flowering Entry Experimental Cran. 422 Experimental Cran. 423 Experimental Cran. 424 Experimental Cran. 425 Cran 028 Michicran White kidney 5408 White kidney 61144 Light red kidney 9482 Mecosta Manitou 70684 70700 70688 Redkloud Sacramento Charlevoix Montcalm Plant type Yield in lbs/acre 36 35 37 37 42 44 37 35 40 41 40 35 35 35 35 36 40 40 bush bush bush bush bush vine bush bush bush bush bush bush bush bush bush bush bush bush 2570 2469 2575 2677 2721 2198 2301 2396 2622 2468 2245 2674 2477 2678 2505 2772 2213 2295 The experimental cranberry line 422, 423, 424, 425 are early matur­ ing bush types that yielded quite well, in comparison to the later vine Michicran. Cran 028 also yielded quite well in this test, well above Michicran. The new light red kidney strain 9482 has continued to look unusually attractive in the field—plants are upstanding, vigorous, abundantly podded, and pods at maturity are not discolored. Yield has been excellent, exceeding the older standards Manitou and Mecosta. The early light red kidneys represented by 70688 also performed well. MSU #70688 is now under increase and consideration for release as a halo-blight resistant early maturing light red. The early Sacramento was the highest yielding entry in this test. DEPARTMENT OF CROP AND SOIL SCIENCES 317 Agriculture Hall MICHIGAN STATE UNIVERSITY EAST LANSING, MI 48824 Bulk Rate U.S. Postage PAID Permit No. 979 Lansing, Mich. MSU IS AN AFFIRMATIVE ACTION/EQUAL OPPORTUNITY INSTITUTION