File 1980 Research Report MONTCALM EXPERIMENT STATION Michigan State University Agricultural Experiment Station 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 received and are hereby gratefully acknowledged. Special recognition is given to Mr. Theron Comden for his devoted cooperation and assistance in many of the day-to-day operations and personal services. TABLE OF CONTENTS Page INTRODUCTION, WEATHER AND GENERAL MANAGEMENT .... ................... 1 1980 Introduction of New Potato Varieties R.W. Chase and R.B. Kitchen................................. 4' 1980 Potato Variety Evaluations R.W. Chase and R.B. Kitchen................................. 7 Early Variety - Spacing Trial R.W. Chase and R.B. Kitchen............................. . Variety Evaluations for Frozen Processing R.W. Chase, R.B. Kitchen, G. Vogt and R. Smith......................... 20 North Central Region Potato Trial R.W. Chase and R.B. Kitchen ............................................. 23 Weed Control in Potatoes William Meggitt and Richard Chase ................. . ................. 26 Nitrogen Studies with Potatoes M.L. Vitosh............ 28 Phosphorus Study with Russet Burbanks M.L. Vitosh............................................................. 34 The Influence of Selected Production Management Inputs on the Yield, M.L. Vitosh, G.W. Bird, E. Grafius, R.W. Chase and H.C. Olsen ..... The Relationship of Variety and Nitrogen to Yield, Specific Gravity, Quality, and Storability of Potatoes 40 17 Sucrose and Processing Quality J.N. Cash, C. Senterre and M.R. McLellan............................... 49 Soil Insect Control Studies Arthur L. Wells................................. 57 Biology and Control Strategies for Insect Pests of Potatoes E. Grafius, M.A. Otto, E. Morrow, and H.C. Olsen....................... 61 Foliar Insect Control Arthur L. Wells................................................ 77 Effects of Nematocides on Pratylenchus Penetrans and Potato Yields G. W. Bird and H.C. Olsen................................................ 85 Effect of Pre-Plant Soil Treatments on the Control of Potato Scab, H. S. Potter....................................... 87 Effect of Delayed Planting of Cut Potato Seed and Chemical Seed Piece H.S. Potter....................... 90 Treatment on Stand and Yield - 1980 1979, 1980 Page of Early and Late Blight of Potatoes l980 Trials with Systemic Surface Protectant Fungicides for Control H. Spencer Potter....................................................... . 92 1980 Fungigation Trials for Control of Late Blight on Potatoes H. Spencer Potter.......................................................... 94 1980 Foliar Spray Trials for Disease Control on Potatoes H. Spencer Potter.......................................................... 96 Influence of Selected Production Management Inputs on Weight Loss and B.F. Cargill................................................................ 98 Quality of Stored Potatoes Due to Handling, Prestorage Treatments, and B.F. Cargill.............................................................. 110 Corn Hybrids, Plant Population and Irrigation E.C. Rossman and Keith Dysinger..................................... 130 U.S.D.A., Dry Bean Food Value, Processing Quality and Yield Potential G.L. Hosfield, M.A. Uebersax, M.W. Adams, A. Ghaderi, J.L. Taylor Improvement Program N. Wassimi, J.A. Izquierdo and G.N. Agbo.............................. 136 Market Quality of Stored Potatoes Due to Storage Environments Storage Environments Dry Bean Varietal Testing - Colored Beans M.W. Adams and J.L. Taylor............................................... 142 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 fourteen 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 research obtained at this facility during 1980. 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 thirteen year temperature and rainfall data. Temperatures during 1980 were not too much different than the 13 year average. There were many cloudy and high humidity days during August and September. During the entire growing season there were only two days that the temperature reached 90◦. During the period of August through September much of the temperature and relative humidity conditions were very conducive to the development of late blight. The fungicide spray program was increased and copper was included to protect the crop from late blight. Rainfall during September was much greater than the 13 year average. Greater amounts during September have occurred only in 1977 and 1970. Irrigation applications of slightly less than one inch each were made eight times (June 29, July 4, 8, 12, 15, 19, August 4, 13). SOIL TESTS Soil test results for the general plot area were: Pounds per Acre Pounds per Acre P pH 6.8 489 Pounds per Acre Pounds per Acre Mg 213 Ca 1067 K 247 Percent organic matter 1.8 Table 1. The 13 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 6-month average September September Max Min Max 6-month average Min 61 56 54 53 47 54 57 48 58 62 50 50 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 198049 3169 42735081588158 70497148 13-year Average 53 50 55 56 50 58 52 56 57 50 50 55 58 56 57 53 57 60 56 58 53 52 57 55 50 49 51 54 49 48 45 44 46 53 52 47 41 43 47 39 47 42 41 48 41 47 45 44 62 67 65 65 70 63 62 73 63 80 67 66 55 59 60 55 57 60 57 57 58 61 56 57 74 70 72 81 72 77 73 75 79 76 78 74 37 35 35 31 30 36 36 28 35 37 31 33 33 80 80 80 82 79 79 81 80 81 85 81 82 81 74 73 70 73 69 73 68 65 70 70 75 76 71 81 82 80 80 76 80 77 79 80 77 82 77 79 73 74 73 76 73 74 70 70 71 75 72 71 49 67 44 75 53 54 50 49 45 48 48 51 48 49 48 50 49 49 58 56 empty table empty table cell cell Table 2. The 13-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 1977 1978 1979 1980 13-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 2.62 4.90 3.65 4.09 0.93 1.96 3.91 4.83 2.05 4.03 0.46 1.35 1.68 1.65 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 3.78 1.31 1.79 6.54 2.67 7.28 3.94 6.18 11.25 1.44 2.61 5.90 3.69 1.23 2.63 3.67 1.22 3.83 2.36 2.39 2.71 1.50 2.39 1.89 1.09 2.64 3.21 6.59 21.99 2.27 17.32 18.16 28.52 11.91 19.53 19.13 23.97 25.87 15.86 17.39 16.80 12.85 3.30 0.58 7.18 4.00 2.60 1.33 1.81 3.07 1.40 8.62 2.77 0.04 19.18 4.45 3.33 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: - 0-0-60 - 200 lbs/A Plow down Banded at planting - 19-19-19 - 500 lbs/A Sidedressed at hilling - 46-0-0 - 150 lbs/A Alfalfa cover crop plowed down. HERBICIDES Early preemergence alachlor (Lasso) at 2 lbs/A followed by delayed preemergence of metribuzin (Sencor) at 1/2 lb/A. DISEASE & INSECT CONTROL Systemic insecticide Temik was applied at 3 lbs/A. Foliar fungicide and insecticide sprays were as follows: June 11 June 27 July 11 July 18 July 25 August 2 August 9 August 12 August 23 August 30 Sept. 5 Top killed prior to harvest with Paraquat one quart/A plow X77 at 8 oz/100 gallons Sevin Thiodan Bravo Bravo Bravo Bravo + Monitor Bravo ± Thiodan Bravo Bravo + Thiodan Bravo + Copper Bravo + Copper 1980 INTRODUCTION OF NEW POTATO VARIETIES R.W. Chase & R.B. Kitchen The introduction program conducted at the Lennard Farm in Levering was maintained at approximately the same level as in 1979. Forty-seven named varieties and advanced selections plus 35 new Michigan selections were included in the 1980 introduction program. Single tubers are cut once and the two seed pieces are planted as a tuber unit. This procedure minimizes differences in seed piece variation yet still provides two plants for evaluation. Frequent rogueings are made to eliminate undesirable selections. Top killing and harvest are timed so that late season disease infestations are minimized. A major and continuing source of cultivars is from the USDA-Beltsville program with 6 names varieties and 12 advanced selections. Many of these selections show potential suitability to the Michigan area. Virus free tubers of Denali, Atlantic and Onaway were obtained from Vancouver, B.C. and these were increased in 1980. The performance of several of these selections in the 10 hill observation plot planted at the Montcalm Research Farm is shown in Table 1. Of the 35 new selections from the Michigan potato breeding program, 16 were judged as being worthy of further evaluation based on their performance at the Montcalm Research Farm. The parentage and performance of these selections is summarized in Table 2. Table 3 provides an inventory of the current selections. Attempts will be made to obtain the maximum results from the seed produced in this program. All selections will be included in performance studies at the Research Farm and certain selections will be used in the overstate trials. Offerings will also be made to seed producers who wish to introduce new varieties into their seed plot program and insofar as possible these tubers will be indexed in the greenhouse before the 1981 planting. Table 1 - 10 Hill Observation Trials - Montcalm Research Farm Total cwt/A No. 1 cwt/A % No. 1 Selection USDA-Beltsville 390 398 367 296 406 429 328 374 265 328 476 B7154-10 USDA-Beltsville B7516-7 B7516-9 USDA-Beltsville B7802-2 USDA-Beltsville B7805-1 USDA-Beltsville B7859-2 USDA-Beltsville USDA-Beltsville B8528-3 B8934-4 USDA-Beltsville B8943-4 USDA-Beltsville B8972-1 USDA-Beltsville Delta Gold USDA-Beltsville MSU MS2-302 MSU MS4-439 MSU MS401-2 MSU MS402-4 MSU MS402-5 Aberdeen-Idaho A66107-12 Aberdeen-Idaho A68678-1 A72687-11 Aberdeen-Idaho 475 287 289 211 320 413 523 335 Campbell 13 Aberdeen-Idaho Maine CA027 Aberdeen-Idaho Guelph 670-11 Aberdeen-Idaho 445 601 663 312 351 304 265 390 367 218 281 133 164 445 374 242 226 109 250 287 460 296 359 546 632 80.0 88.2 82.8 89.5 96.1 85.5 66.5 75.1 50.2 50.0 93.5 78.7 84.3 78.2 51.7 78.1 69.5 88.0 88.4 80.7 90.8 95.3 % Over 3 1/4 0 11.8 14.9 0 26.9 7.3 0 8.3 0 0 32.8 0 10.8 0 0 4.9 5.7 23.9 0 17.5 14.3 16.5 Specific Gravity Chip Rating empty table cell 1.053 1.073 1.064 1.056 1.064 1.078 1.070 1.069 1.062 1.069 1.083 1.077 1.083 1.071 1.077 1.073 1.064 1.081 1.074 1.072 1.083 1.090 1.5 2.5 3.0 2.5 3.5 2.0 3.0 3.0 4.0 2.5 2.5 2.5 1.5 3.0 1.5 2.5 3.0 2.0 2.5 2.0 2.5 3.5 Good type; growth cracks Deep eyes Not uniform Very smooth skin; rough Smooth; Good type; Some scab Some deep scab Good type; very small Good type; Some growth crack Deep scab; small Good appearance; small Some scab Good type, some scab; yellow Very rough Small; some scab Too small-discard Good type: small Type not uniform Good type Very pointed; discard Good type; smooth skin Smooth; good type Some scab Table 2 - New MSU Selections Atlantic x Michibonne Selection Atlantic x Michibonne Total Fleshcolor cwt/A No. 1 cwt/A % No. 1 % Over 3 1/4 Specific Gravity Chip Rating Comments White White White White White White White Yellow Cream White White White 700-70 700-79 700-83 700-88 Atlantic x MichigamiAtlantic x Michigami 701-22 Atlantic x WischipAtlantic x Wischip 702-80 702-91 Atlantic x WischipAtlantic x Wischip 704-3 704-10 704-17 Michigami x AtlanticMichigami x Atlantic 709-21 2-171 x Michigami2-171 x Michigami 714-10 3-22 x Atlantic3-22 x Atlantic 716-15 3-69 x Wischip3-69 x Wischip 718-6 718-11 4-198 x Atlantic4-198 x Atlantic 719-38 Cream Cream White 484 367 3-22 x Atlantic 75.8 3-22 x Atlantic 0 3-22 x Atlantic 3-22 x Atlantic 3-22 x Atlantic3-22 x Atlantic 3-22 x Atlantic White 468 390 83.3 0 3-69 x Wischip 3-69 x Wischip3-69 x Wischip 3-69 x Wischip3-69 x Wischip3-69 x Wischip3-69 x Wischip 413 406 382 343 4-198 x Atlantic 92.5 84.5 4-198 x Atlantic 32.1 0 4-198 x Atlantic 4-198 x Atlantic 4-198 x Atlantic4-198 x Atlantic 4-198 x Atlantic 414 374 90.3 18.9 1.070 1.5 Early 491 343 468 359 460 452 452 374 406 499 530 413 523 460 530 476 530 445 507 554 92.6 83.1 89.5 78.0 8.8 3.8 16.4 5.1 1.081 1.081 1.075 1.070 Atlantic x Michigami 1.5 1.5 1.5 1.5 Atlantic x Michigami Late Early Late Late Atlantic x Michigami Atlantic x Michigami Atlantic x Michigami Atlantic x Michigami Atlantic x Michigami Atlantic x Wischip Atlantic x Wischip 86.8 10.3 Atlantic x Wischip 1.078 Atlantic x Wischip 1.5 Atlantic x Wischip Late Atlantic x Wischip Atlantic x Wischip Atlantic x Wischip Atlantic x Wischip 95.0 85.5 Atlantic x Wischip 1.073 1.077 Atlantic x Wischip 1.0 1.5 Atlantic x Wischip Early Early Atlantic x Wischip 13.1 13.2 Atlantic x Wischip Michigami x Atlantic Michigami x Atlantic Michigami x Atlantic 84.0 80.1 90.1 0 0 25.4 1.075 1.084 1.077 Michigami x Atlantic 1.5 2.0 3.0 Michigami x Atlantic Early Early Early Michigami x Atlantic Michigami x Atlantic 382 367 2-171 x Michigami 96.1 2-171 x Michigami 8.2 2-171 x Michigami 2-171 x Michigami 2-171 x Michigami 2-171 x Michigami 2-171 x Michigami 1.080 1.075 1.088 1.083 1.075 3.5 1.0 1.0 2.0 1.5 Early Early Late Late Early 1980 POTATO VARIETY EVALUATIONS R.W. Chase & R.B. Kitchen Department of Crop and Soil Sciences A. Dates of Harvest of Several Potato Varieties One of the research projects funded by the MPIC is the intensive dates- of-harvest study conducted at the Montcalm Research Farm. Three blocks each containing 104 ten foot plots were planted on May 5. Each block contained 26 varieties and advanced selections planted in a randomized complete block design with four replications. One block was harvested August 11, a second on August 27 and the third on September 24. At each date, yields of market­ able tubers (over 2 inches), specific gravity, chip scores and internal evaluations were determined. The plot area received 200 pounds/A plow down of 0-0-60, 500 lbs/A 19-19-19 in the planter and 150-lbs/A 45-0-0 sidedressed. The plow down crop was a one year old stand of alfalfa. Temik at 20 lbs/A was applied at planting. Alachlor (Lasso) 2 lb/A was applied early preemergence and metribuzin (Sencor) 0.5 lbs/A was applied delayed preemergence. The plots were irrigated. Results The yield performance for each date of harvest is summarized in Table 1. Over all the varieties there was a general increase in yield with the later harvests, however, there was no change in specific gravity. Varieties which reached their optimum yields early and could therefore be considered as having an earlier marketable yield were Yukon, Onaway, Oceania, MS 402-1, Superior, MS 403-2 and MS 402-6. Varieties which performed as being inter­ mediate were Crystal, Dakchip, B7516-9, Buckskin, Monona and Allagash Russet. Varieties considered as late were B6987-184, Rideau, Lemhi, Russette (B7583-6), Croatan, Michimac, Belchip, Katahdin, Atlantic, Denali, CA-027 and Russet Burbank. Table 2 summarizes the internal defects based on a randomly selected 25 tuber sample. Variety observations: Yukon is a Canadian yellow flesh variety. It has a very attractive appearance, uniformity, smoothness and appears to mature early. Specific gravity is medium. It did produce acceptable chips when harvested. B6987-184 is an advanced selection from the USDA-Beltsville program and may soon be officially released. Tubers are elongated and it has a very high specific gravity. Yields at the Montcalm Farm were very good, however, at some of the farmer locations it did not size as well. Pioneer is a long, red skin variety. It is included because of its potential as an early maturing, long tuber which is suitable for frozen processing before the maincrop of Russet Burbank. Crystal is a recent release from North Dakota. Its tubers are elongated and it does have a vigorous vine growth. It has yielded above average; however, specific gravity readings were medium low. At some outstate locations scab was noted and it was often the deeper, pitted type. Onaway included as a check variety. Rideau is a red skin variety released by Canada in 1979. Tubers are round, smooth, shallow eye and have a bright red skin which holds its color well. It matures medium late and yields very well. Dakchip is a recent release from North Dakota with a mid season maturity. It yielded slightly above average, however, specific gravity is medium low and the tubers are not as uniform and smooth particularly for tablestock use. Also in both 1979 and 1980 vascular discolorations have been significant. Lemhi a recent release from Idaho is a long smooth russet which produces a higher percentage of number ones than does Russet Burbank. Maturity is similar to Russet Burbank. A major concern is the high incidence of hollow heart noted in most of our plots and also reported in other states. Russette (B7583-6) is a recent release from the USDA-Beltsville. It is a late maturity, oblong russet which is slow to establish early in the growing season. Some hollow heart was noted in 1980 but this had not been noted in earlier tests. Croatan was released from North Carolina and is a late maturing round white. It has not shown any improved features over existing varieties and will be deleted from further trials. Oceania is an early maturing round white variety released by USDA- Beltsville. Specific gravity is low and there were reports of serious blackleg susceptibility in certain 1980 plantings. Tubers are very smooth and uniform in type. Michimac is a late maturing round white from the Michigan program. It has a high yield potential and its greatest suitability would be for out of storage fresh pack. It should not be grown on fields which scab is known to be a problem. Belchip is a late maturing variety released from USDA-Beltsville. It yields above average, medium specific gravity and appears to have fewer internal defects than does Atlantic. Tubers are not as uniform and attractive as Atlantic and so it may not be as desirable for freshpack. Chip performance has been acceptable. B7516-9 is an advanced selection from USDA-Beltsville which matures early. Yields are about average and dry matter is similar to Oceania. Katahdin is included as a late maturing check variety. MS402-1 is an advanced selection from Michigan. It matures early and yield potential appears to be below average. Internal defects are minimal and tubers are well shaped, and shallow eyed and specific gravity was low. Atlantic continues to yield well with desirable specific gravity and good chip quality-. Hollow heart and internal necrosis continue to be its greatest limitations. Denali is a late maturing variety with high specific gravity. It yields well above average and internal defects have not been serious. Vascular discoloration has been noted at some locations. Scab has also been observed at certain locations and growers should avoid fields where scab is known to be a problem. Tubers are oval to oblong and fairly smooth. Superior is included as an early maturing variety. Buckskin is a variety released from Pennsylvania which we have had in our tests for 3 years. Yields have been below average and it is a variety which is slow to establish early in the growing season. It is being deleted from further testing. CA 027 is an advanced round white seedling from Maine which was first added to our trials this year. It is a late maturing variety which is well shaped, smooth and yielded above average at the late harvest. Russet Burbank and Monona are included as standard check varieties. MS 403-2 and MS 402-6 are two advanced selections from Michigan which will be deleted from further testing. Yields are too low to offer any potential. Allagash Russet is an oblong to round russet released in 1980 from Maine. Yields were well below average and dry matter was low. Maturity is early so potential may be similar to Belrus as an early fresh russet potato. Table 3 summarizes the results of the sucrose analysis for each variety at the different harvests. Studies are currently underway with Dr. Cash to determine the feasibility of determining the sucrose level as a predictor of maturity for harvest and its processing potential from storage. At this time, the relationship under our Michigan growing conditions has not been fully established. Table 3 also shows the chipping performance of these several varieties stored at 55° since harvest. Several varieties remained in good chipping condition throughout the storage period. Ratings of a 2.0 or less are producing very acceptable chips. Similar samples have been stored at 42 and these will be reconditioned in February to determine those varieties which will recondition. Table 4 summarizes the chip performance of several varieties from the 1979 variety testing program. These selections were stored at 40° until January 22, 1980 when the reconditioning was initiated. The samples were held at 65° and chip samples were made at 0, 2, 4 and 6 weeks. Table 1. The yield and specific gravity of several potato varieties harvested on three different dates. (Montcalm Research Farm - 1980) Variety Aug. 11 Total Aug. 11 No. 1* Aug. 11 S.G. Aug. 11 Chip** Color Aug. 27 Total Aug. 27 No. 1* Aug. 27 S.G. Aug. 27 Chip** Color Sept. 24 Total Sept. 24 No. 1* Sept. 24 S.G. Maturity*** Sept. 24 Chip** Color 418 412 418 404 382 367 381 367 343 388 385 367 332 351 345 312 324 329 307 309 301 357 290 264 265 304 347 378 357 353 337 329 329 321 315 312 312 310 307 300 298 290 279 276 275 273 267 265 256 231 231 207 206 293 384 410 421 449 356 412 385 374 326 357 334 353 382 323 281 304 368 373 265 406 317 357 317 189 253 240 344 Yukon B6987-184 Pioneer Crystal Onaway Rideau Dakchip Lemhi Russette Croatan Oceania Michimac Belchip B7516-9 Kathadin MS 402-1 Atlantic Denali Superior Buckskin CA 027 Russet Burbank Monona MS 403-2 Allagash MS 402-6 Average 407 449 459 487 378 423 415 445 343 410 357 382 406 359 314 328 401 415 285 424 340 446 353 206 290 303 378 *Pickouts and tubers under 2” diameter excluded. **Based on scale of 1-5. 1 = lightest, 5 = darkest and not acceptable ***1 = early maturity, similar to Norland; 5 - a late maturity, similar to Russet Burbank 1.0 1.0 2.0 1.5 3.0 2.0 1.0 1.5 1.5 1.5 2.0 2.0 1.0 1.0 1.5 1.0 1.0 1.0 1.0 1.0 1.0 2.0 1.5 1.0 1.0 1.0 empty table cell 1.0 1.0 1.5 1.0 3.0 2.0 1.5 1.0 1.5 2.0 2.5 2.0 1.0 1.5 1.5 1.0 1.0 1.0 1.5 1.0 1.0 1.5 1.0 1.0 1.0 1.0 empty table cell 1.072 1.088 1.068 1.070 1.062 1.071 1.071 1.079 1.074 1.061 1.059 1.065 1.075 1.061 1.060 1.062 1.082 1.088 1.065 1.073 1.073 1.077 1.064 1.071 1.062 1.064 1.070 1.072 1.089 1.074 1.068 1.063 1.070 1.071 1.082 1.075 1.060 1.065 1.067 1.072 1.063 1.067 1.066 1.083 1.083 1.070 1.074 1.071 1.079 1.064 1.073 1.062 1.065 1.071 408 532 527 472 365 484 431 503 431 458 375 501 478 338 396 308 437 497 300 415 460 470 369 271 310 248 415 382 497 481 415 318 462 378 445 398 398 330 460 433 283 353 269 396 451 263 386 415 326 341 236 277 189 369 1.072 1.090 1.070 1.068 1.064 1.071 1.068 1.076 1.072 1.062 1.059 1.064 1.077 1.063 1.064 1.065 1.086 1.087 1.068 1.070 1.072 1.076 1.060 1.070 1.060 1.064 1.070 1.5 1.0 2.0 1.5 4.0 3.0 1.0 2.0 3.0 1.5 1.5 2.5 1.5 1.5 2.0 1.5 1.0 1.5 1.5 1.0 1.5 3.0 1.0 1.5 1.0 1.0 empty table cell 1 3 2 4 2 3 2 4 4 3 1 4 5 3 5 2 4 4 1 4 5 4 3 2 2 1 empty table cell Table 2. Internal defects* of several potato varieties grown at the Montcalm Research Farm - 1980. Variety Yukon B6987-184 Pioneer Crystal Onaway Rideau Dakchip Lemhi Russette Croatan Oceania Michimac Belchip B7516-9 Kathadin MS 402-1 Atlantic Denali Superior Buckskin CA 027 Russett Burbank Monona MS 403-2 Allagash MS 402-6 Aug 11 Hollow --- --- --- --- --- --- --- 4 --- --- --- --- 1 1 --- --- --- --- --- --- --- --- --- --- --- --- Aug 11 Internal Necrosis --- --- --- --- --- --- 1 slight --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 2 slight --- --- Aug 11 Vascular 1 slight 2 slight --- --- 5 slight 1 slight 3 severe 4 slight --- --- --- 2 slight 1 severe 2 slight 1 severe 5 slight 2 slight 2 slight --- --- 2 slight 2 slight 1 slight --- 1 slight 1 slight 1 slight --- Aug 27 Internal Necrosis --- --- --- --- --- --- --- Aug 27 Hollow --- --- --- --- --- --- --- Aug 27 Vascular 3 slight 4 slight 2 slight 1 slight 4 slight 1 slight 1 severe 4 1 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 1 slight --- --- --- --- --- --- 2 slight 1 severe 2 slight 4 slight 1 slight 2 slight 2 slight 1 slight 3 slight 1 slight 1 slight 1 slight 1 slight --- --- --- --- 1 slight --- --- --- --- --- --- --- --- --- 1 slight 1 slight --- --- --- *Based on 25 tuber sample selected at random Sept 24 Internal Necrosis --- --- --- --- --- --- --- 1 slight --- --- --- --- --- --- --- --- 2 brown center --- --- --- 1 slight Sept 24 Hollow --- --- 1 --- --- --- --- --- 4 --- --- --- --- --- 1 --- --- --- --- --- --- 1 --- --- --- Sept 24 Vascular 2 slight 8 slight 4 slight 3 slight 3 slight 4 slight 7 severe 3 slight 1 slight 1 slight --- --- 4 severe 8 slight 1 severe 4 slight 3 slight 5 slight 1 slight 4 severe 5 slight 3 slight 7 slight 5 severe 4 slight 2 slight 4 slight 1 slight --- 1 slight --- --- --- empty table cellempty table cell --- empty table cell Table 3. The sucrose and chip ratings of several potato varieties harvested on 3 different dates. (Montcalm Research Farm - 1980) Variety Sucrose Rating1 Aug. 11 Sucrose Rating1 Aug. 27 Sucrose Rating1 Sept. 24 Chip Rating2 (Jan. 8, 1981) Yukon B6987-184 Pioneer Crystal Onaway Rideau Dakchip Lemhi Russette Croatan Oceania Michimac Belchip B7516-9 Katahdin MS 402-1 Atlantic Denali Superior Buckskin CA027 Russet Burbank Monona MS403-2 Allagash Russet MS402-6 ---- 1.62 0.10 1.74 0.98 1.12 1.85 2.32 0.81 1.19 0.47 0.73 1.01 0.99 1.00 0.83 0.70 0.05 1.80 1.22 0.09 2.02 1.11 1.28 0.81 1.21 0.61 0.25 0.25 0.45 0.38 0.52 0.37 0.85 0.42 0.47 0.50 0.83 0.46 1.05 0.48 0.60 0.17 0.36 0.40 0.60 0.75 0.62 0.32 0.60 0.35 0.45 0.64 0.61 --- 0.85 0.58 1.35 0.73 0.82 0.70 0.73 0.47 0.52 0.38 0.67 1.17 0.29 0.79 0.85 0.52 0.29 0.50 0.58 0.82 0.85 0.50 0.47 4.0 1.0 1.5 1.53 4.0 2.0 1.53 1.53 3.0 ---- 1.5 3.0 1.53 2.0 2.5 2.0 1.03 2.03 2.5 2.03 2.5 1.0 ---- 1.0 ---- ---- 1Sucrose determinations made by Dr. Jerry Cash, Department of Food Science and Human Nutrition. 2Chip score based on a 1-5 scale 1 = lightest, 5 = darkest. Samples stored at 55° since harvest. 3Some individual slices showed dark stem ends. Table 4. The chip ratings of several varieties grown in 1979 and reconditioned in Feb-Mar, 1980. Chip Rating11 Reconditioned at 65° 2 weeks 11Reconditioned at 65° Chip Rating 4 weeks Chip Rating11Reconditioned at 65° 6 1/2 weeks 11 Jan. 22, 1980 Chip Rating 40° Variety Oneida Belrus Superior Kennebec Michimac Atlantic Oceania Belchip Denali Russet Burbank B6987-184 Dakchip Crystal 11Based on a 1-5 scale. 1 = lightest, 5 = darkest 4.5 5.0 5.0 4.5 5.0 4.5 5.0 4.5 5.0 5.0 5.0 4.5 5.0 3.5 3.5 4.0 3.5 4.0 3.0 4.5 4.0 3.5 4.5 --- --- --- --- --- 3.0 4.0 4.0 3.5 4.0 2.5 4.5 3.0 3.5 4.0 --- 3.0 4.0 3.5 3.0 3.5 2.0 3.5 2.0 3.0 3.5 2.0 4.0 3.5 B. Overstate Potato Variety Trials Result-demonstrations of several potato varieties were conducted on three cooperating farms during 1980. The locations were at the Woloszyk Farm in Presque Isle County, Allen Anderson's Farm in Montcalm County, and Shoemaker Bros. in Allegan County. Half acre plantings of several varieties were evaluated at the Lennard Farm in Monroe County and these results were reported by Paul Marks, Monroe County Extension Agriculture Agent in the last issue of the MPIC News. Replicated yield data could not be obtained at the demonstra­ tion on the DuRussel Farm in Washtenaw County so these data are not included. Similar to our procedure in 1979, approximately 35 pounds of seed of each variety were provided to the grower. The seed was cut in their mechanical cutter (except the Shoemaker location) and then planted with their planter so it does receive the usual commercial handling. Twelve varieties were evaluated at each location and the results are summarized in Table 1. It is apparent that environmental conditions were substantially different at each location. Presque Isle County had an extremely dry growing season and this is reflected by the high specific gravity readings and the lower than usual total yields. The percentage of tubers over 3 1/4 inch was much lower than usual and the only varieties which had a significant amount were MS402-1, Belchip, Michimac and Ontario. At the Anderson Farm, average yields were very good and specific gravity was medium reflecting a season of adequate moisture plus irrigation during the growing season and above average soil moisture during September and prior to harvest. At the Shoemaker location yields are favorable, however, specific gravity readings are low and this reflects an above average soil moisture environment from planting and throughout the growing and harvest season. Varieties such as Denali, B6987-184 and Atlantic which are routinely very high were only about medium. Internal defects were greater than desired with several selections show­ in varying degress of vascular discoloration. Hollow heart was very severe on Lemhi, B6987-184 and Atlantic at Allegan County, whereas Russette (B7583-6) had the greatest amount of hollow heart at the Anderson Farm. Varieties showing the greatest amount of internal necrosis and vascular discoloration were Atlantic, Crystal and CA027 at the Anderson Farm. The incidence of internal defects at the Woloszyk Farm was very minimal. Crystal and Dakchip are the two latest releases from North Dakota. Of the two, Crystal seems to be a more vigorous plant with a greater yield potential. Dakchip is less uniform in tuber type and there has been consider­ able vascular discoloration noted in both 1979 and 1980. Crystal is an elongated to oval shaped potato. MS1085 and MS402-1 are two Michigan seedlings which exhibit good tuber type. MS402-1 is medium early in maturity and does have a medium to medium- low specific gravity. Altantic, Belchip, Oceania, Russette (B7583-6) and B6987-184 are all products of Dr. Ray Webb at USDA-Beltsville. Hollow heart continues to be of concern in Atlantic, however, it does yield well, chip color is very desirable and it does have a high specific gravity. Belchip is a high yielding variety with less internal defects than Atlantic, medium specific gravity, however, it is deeper eyed than Atlantic and exhibits a rougher general appearance. Russette is an attractive elongated to blocky russet which yields above average. Specific gravity is medium and it does not appear to be a chipping variety, however, it may have a potential for frozen processing. Oceania is an early maturing variety, low specific gravity and a very smooth potato but appears to be very susceptible to blackleg. B6987-184 is a recent selection which has very high specific gravity. More testing will be needed to determine its adaptability but it does appear promising. Denali continues to yield well above average and consistently has a high specific gravity. Tuber type was very desirable at all locations and it appears to be a variety which sizes uniformly with a small percentage under 2 inches and it does not excessively oversize. Croatan and Buckskin are two selections we have evaluated for at least 3 years and will delete from further testing. Thus far they have not shown any distinct advantages and Buckskin has consistently been a below average yielder, Lemhi is a recent release from Idaho and although it yields well and has a smooth and blocky shape, hollow heart appears to be a major defect. Ontario is a popular variety in the Presque Isle County area and has produced very well. Michimac is a potential consideration for that area and other tablestock areas because it yields well above average; it matures earlier than Sebago or Ontario; it has a vigorous vine growth and it is a smooth and shallow eyed potato. It sets tubers deeper than Katahdin and thereby results in less greenheads. CA027 is a Maine seedling and this is our first year of testing. It appears to be a late maturing round white potato. Table 1. The yield and specific gravity and chip score of several potato varieties grown at 3 out-state locations. Variety Crystal Michimac MS-1085 Ontario Atlantic MS402-1 Dakchip Belchip Denali Oceania B6987-184 Russette (B7583-6) Croatan Buckskin Lemhi CA027 Average Woloszyk Presque Isle County Total (cwt/A) Woloszyk Woloszyk Presque Isle County Presque Isle County Over 2" Specific gravity (cwt/A) Anderson Montcalm County Total (cwt/A) Anderson Montcalm County Over 2" (cwt/A) Anderson Montcalm County Specific gravity Anderson Montcalm County Chip Score* Shoemaker Allegan County Total (cwt/A) Shoemaker Allegan County Over 2" (cwt/A) Shoemaker Allegan County Specific gravity Shoemaker Allegan County Chip* Score 293 292 285 284 273 273 268 254 254 236 218 201 --- --- —-- —-- 261 1.084 1.077 1.091 1.082 1.092 1.077 1.077 1.085 1.096 1.080 1.096 1.088 273 281 230 271 260 257 252 241 230 217 198 190 --- ----- --- ----- ----- --- --- ----- 1.085 242 --- 423 412 --- --- 423 301 379 410 339 275 379 354 303 --- 395 396 392 --- --- 396 --- 275 356 379 306 251 359 320 282 --- 374 1.066 1.066 ----- ----- 1.082 --- 1.066 1.068 1.089 1.061 1.088 1.073 1.063 1.071 ----- 1.075 2.0 3.5 --- --- 1.5 --- 1.5 1.5 2.0 1.5 2.0 4.0 1.5 1.0 --- 2.0 366 341 1.072 --- 230 306 319 --- 249 --- 288 279 373 --- 313 300 315 275 262 202 292 293 --- 226 --- 271 265 352 --- 281 281 292 249 228 --- 292 --- 269 2.0 3.0 2.0 1.058 1.058 1.063 ----- —-- 1.074 ----- —-- 1.5 1.057 1.068 1.078 ----- 1.081 1.068 1.058 1.067 1.064 ----- 1.066 --- 1.5 1.5 2.0 -—- 2.5 4.0 1.5 2.0 2.5 --- empty table cell Planted May 23/Harvested Sept 29 Planted May 23/Harvested Sept 29 Planted May 23/Harvested Sept 29 Planted May 20/Harvested Oct 9 Planted May 20/Harvested Oct 9 Planted May 20/Harvested Oct 9 Planted May 20/Harvested Oct 9 Planted May 16/Harvested Sept 26 Planted May 16/Harvested Sept 26 Planted May 16/Harvested Sept 26 Planted May 16/Harvested Sept 26 *Based on a 1-5 scale. 1 = lighest, 5 = darkest and not acceptable. EARLY VARIETY- SPACING TRIAL R.W. Chase & R.B. Kitchen Department of Crop and Soil Sciences Procedure A study designed to evaluate the effect of spacing on several new varieties was conducted at the Montcalm Research Farm. Spacings of 7, 9 and 11 inches were compared for Belrus, Oceania, Allagash, Russet and Atlantic in comparison with the standard early varieties, Onaway and Superior. Cut seed was used for all plantings except Allagash Russet. Results For all varieties except Oceania the greatest total yield was obtained at the 7 inch spacing (Table 1). This was particularly true with Allagash, Onaway and Superior when compared with the 11 inch spacing. In terms of total yield, spacing had little effect on Atlantic. Belrus has been in our test plots for the past 3 years and in most lower Michigan tests it has not yielded well. It is an early maturing long russet with excellent type and a high percentage of US No. 1s. Its market advantage is as an early maturing (early August) long russet which would allow it to compete as a fresh market russet as compared to Russet Burbanks still being marketed out of storage. Its yield potential appears to be greater in Northern Michigan. The effect of spacing had little effect on the total yield, however the yield and percent No. 1s were higher at the 11 inch spacing. At the closer spacing there was a high percentage of B size tubers. There was no effect on the percent over 10 ounce. Oceania produced the greatest total yield and US No. 1s at the 11 inch spacing. Oceania is an early maturing round white which when compared to Onaway is suitable for chip processing, which allows it to be marketed either way. It is very smooth and has a low specific gravity. It may have some susceptibility to black leg and serious stand problems were reported in 1980. Allagash Russet is a recent release from Maine. It is a roundish to oblong russet with a lighter russet than Belrus. In 1980, our first year of testing, it was early maturing and below average in yield. The greatest yield occurred at the 7 inch spacing, however in terms of U.S. No. 1s the 9 inch space seems best. Onaway and Superior were included as standard early maturing varieties and performance of both was best at the 7 inch space. Atlantic is a variety which unlike many varieties seems to have a wide range of marketable maturity. In our dates-of-harvest study, this variety has yielded well at the earliest harvest and it continues to increase with later harvests. Its yields at the August 27 harvest date were greater than for Onaway, specific gravity is much higher and it produces a very acceptable chip. This variety appears to perform best at the closer spacing where it seems to have less incidence of hollow heart and the percentage of tubers under 3 1/4 inch is considerably reduced. Internal defects for all varieties were very minimal except for the hollow heart noted with Atlantic. It is of interest to note that the specific gravity readings were highest at the 11 inch spacing for Belrus, Oceania and Superior, however the reverse was true for Allagash Russet, Onaway and Atlantic. Based on these results and other observations, it appears that the closer spacing of 7-8 inch (with irrigation) is most desirable for Onaway, Superior and Atlantic. Eleven inch seems best for Belrus, Oceania and 9 inch for Allagash Russet. TABLE 1. EARLY VARIETY - SPACING TRIAL. Montcalm Research Farm Planted May 7, 1980 Harvested August 27, 1980 whole seed except Allagash Present Present Internal Defects Internal Defects Necrosis Variety Belrus Belrus Belrus Oceania Oceania Oceania Allagash Allagash Allagash Onaway Onaway Onaway Superior Superior Superior Atlantic Atlantic Atlantic Spacing Total cwt/A No. 1 cwt/A 7 9 11 7 9 11 7 9 11 7 9 11 7 9 11 7 9 11 302 275 287 421 414 464 351 347 302 519 513 456 435 359 330 552 534 542 199 191 224 351 353 400 289 300 250 460 456 401 393 324 306 509 489 513 No. 1 65.9 69.5 78.0 83.4 85.3 86.2 82.3 86.5 82.8 88.6 88.9 87.9 90.3 90.3 92.7 92.2 91.6 94.6 Over 3 1/4 3.9 2.2 3.4 2.3 6.1 3.4 5.0 7.3 10.3 3.0 3.0 8.6 0 4.3 10.6 11.7 9.9 20.5 Specific Gravity 1.070 1.071 1.073 1.059 1.061 1.063 1.061 1.061 1.060 1.066 1.066 1.063 1.066 1.063 1.068 1.084 1.083 1.082 Vascular 2 slight 1 slight 2 slight 0 0 3 slight 1 severe 2 slight 1 slight 1 slight 3 slight 2 slight 1 severe 6 slight 4 slight 7 slight 2 slight 3 slight 2 slight 1 severe 1 slight 0 0 0 0 0 0 0 0 0 0 0 0 1 slight 0 0 0 0 1 Internal Defects Hollow 0 0 0 0 0 0 0 1 1 0 0 0 0 0 1 1 1 4 VARIETY EVALUATIONS FOR FROZEN PROCESSING *, G. Vogt R.W. Chase ** *, R.B. Kitchen *, R. Smith *Department of Crop and Soil Sciences **Ore-Ida Foods, Inc. Each year advanced selections are evaluated for their production and suit­ ability for the manufacture of frozen Erench fries. Selections that mature early and late are planted in 2 separate studies. Yields, size distribution, specific gravity, fry color, internal defects and reducing sugars are determined for each cultivar. Fertilizer treatments are the same as used for all plots as described in the Report introduction. Results The results of the five early maturing selections are shown in Table 1. In previous tests and in 1980 the Pioneer variety had produced favorable results. It is a long red skin tuber which is very uniform in type. All selections pro­ duced a very high percentage of tubers under 4 ounces which is not desirable for frozen French fry production. The A68599-1 had the highest specific gravity and the greatest percentage of tubers over 10 ounces. Fry colors on all were within acceptable limits. ALR 22-2 was the earliest to mature on July 30. Table 2 summarizes the results of the late harvest. Generally there was a high percentage of tubers under 4 ounces, however, it was less than those harvested earlier with Allagash Russet and B8528-3 having the greatest. Lehmi yielded very well and had the highest percent over 10 ounce however the incidence of hollow heart was high. Those with the highest level of reducing sugars generally cooked darker. Generally speaking, the USDA-Beltsville selections B8972-1, B8528-3, Russette yielded below average and maturities were much earlier than the others. Table 1. The yield, quality and cooking performance of five advanced selections. empty table cell Pioneer A68599-1 A66107-12 ALR22-2 A72687-11 Total (cwt/A) 404 382 362 359 302 4-10 oz. Percent 62.4 59.2 59.2 63.6 68.0 Percent Percent >4 oz. 22.6 21.5 29.8 24.7 21.5 over 10 oz. 12.1 18.3 7.8 9.0 6.3 Percent pick outs 2.9 1.0 3.2 2.7 4.2 Specific Gravity 1.072 1.078 1.072 1.066 1.072 Chip* Color 1 1 3 3 2 Fry Color** 0-1 21 22 18 18 25 Fry Color** 2-3 1 2 6 5 0 0 0 0 0 0 0 0 0 0 0 Fry Color** 4+ Hollow heart Vas. dis. No. Tubers 22 24 24 23 25 3 slight 0 0 1 slight 1 severe 4 slight 15 jelly end rot Planted: May 6, 1980 Harvested: August 28, 1980 * Potato chip color rating based on 1-5 scale, 1 = light and very acceptable; 5 = dark and not acceptable ** Center slab fry evaluation on September 15. Ten pound sample; 3/8 inch slice/ fat temp. 365°F and cooked for 3 minutes. Table 2. The yield, quality and cooking performance of 12 potato selections. empty table cell Total ctw/A Percent 4-6oz. Percent 6-10oz. Percent over 10oz. Percent Under 4oz. Percent 2's Specific Gravity Percent Reducing Sugars Center Slab Internal Center Slab Center Slab Fry Color Defects Fry Color Fry Color 4+ 2-3 Hollow 0-1 heart Internal Defects Vas. Internal Defects Browning WC612-13 A68710-5 Lemhi A72685-2 A67142-1 R. Burbank Russette A72545-7 WC521-12 B8528-3 B8972-1 Allagash Russet Average 500 457 438 423 408 402 342 333 291 288 261 245 366 34.7 21.6 19.0 26.1 27.2 22.1 31.0 30.3 29.5 29.4 22.1 34.5 34.8 22.3 32.3 33.5 32.9 14.3 36.4 32.0 30.7 15.7 10.4 17.5 empty table cell 8.0 14.2 21.7 15.8 13.7 6.7 10.4 4.8 8.4 1.7 0 1.3 empty table cell 21.2 14.0 16.1 15.4 17.4 24.1 21.7 21.1 27.6 52.7 66.1 46.3 1.3 27.9 10.9 9.2 8.8 32.8 0.5 11.8 3.8 0.5 1.4 0.4 1.087 1.075 1.079 1.090 1.079 1.079 1.079 1.078 1.093 1.075 1.073 1.059 1.078 .273 .279 .093 .105 .087 .161 .248 .304 .093 .074 .060 .072 0 5 1 5 6 15 5 23 0 0 0 0 23 19 20 16 17 9 17 0 24 24 25 25 0 0 0 0 0 0 0 0 0 0 0 0 empty table cell 0 0 5 0 0 0 4 0 5 0 2 0 empty table cell 1 slight 0 0 1 slight 0 0 1 4 slight 0 3 slight 0 2 slight empty table cell 3 slight 0 1 severe 1 1 slight 0 3 slight 0 empty table cell empty table cell empty table cell empty table cell 0 0 0 0 empty table cellempty table cell empty table cell empty table cell Planted: May 6, 1980 Harvested: September 25, 1980 NORTH CENTRAL REGIONAL POTATO TRIALS R.W. Chase & R.B. Kitchen Department of Crop and Soil Sciences Each year Michigan conducts a North Central Regional Potato Trial. Michigan is one of 16 locations of this trial which is designed to evaluate advanced selections under a wide range of growing conditions. Participants are the North Central states, plus Manitoba, Alberta, Louisiana, Colorado and Kentucky. Potato plant breeders are able to submit up to three advanced selections for the trials. Thirteen advanced selections were entered in the 1980 trial and these were compared with the standard varieties Red Pontiac, Russet Burbank, Norland and Norchip. Planting was made May 7 and harvested September 24, 1980. The entries are as follows: PARENTAGE Platte x 48.60-H35 A29.62-3 x 46.66-1 Sioux x 49.62-1 32.63-9 x Norchief 32.63-9 x Chieftain 366.65-3 x G6743-5 Wisc. 634 x Kennebec Wisc. 639 x Kennebec Norchief x Norland La.12-142 x La.62-104 ND8987-3R x ND9403-20R Wc 285-83 x B7587-2 Check Check Check Check empty table cell MATURITY Late Medium Medium Intermediate Intermediate Late Med-Late Med-Late Med-Late Med-Late Very Early Medium Late Very Late Early Medium empty table cell OTHER COLOR INFORMATION White Chipper Russet Chipper,Scab Resistant White Chipper,Scab Resistant Late Blight Resistant; Red Some Scab Resistant Red Good Scab and Late Blight Resistance Russet Good Scab and Late Blight Resistance, Blocky White Good Solids - Chips White Good Solids - Chips Red Good Color Red Scab Resistant Russet empty table cell Red Good Color and Type Good Shape Russet empty table cell Red Russet empty table cell empty table cell Red empty table cell White ELECTION NO. eb.A129.69-l eb.A71.72-1 eb.A219.70-3 N 8742 N 8757 N 9319 isc. 723 isc. 726 isc. 806R a.42-38 K 34-2 D146-4R ND 14-1 ed Pontiac usset Burbank orland orchip Results Table 1 summarizes the yield, total solids and characteristics of the different selections. Average total solids (17.7% or 1.068 specific gravity) were low which may be related to the wet soil conditions during the maturity and harvest period. Table 2 summarizes the internal and external defects of the tubers. Vascular discolorations were noted in most selections, however for most selections the incidence was minor. Table 1. The yield, total solids and characteristics of several varieties entered in the 1980 North Central Potato Variety Trial. Aver.1/ Mat. Most2/ Most2/ Representa­ Representa­ tive Scab tive Scab Type Area 0 0 CWT/A Aver. Yield CWT/A Aver. Yield US #1 Aver. Percent U.S #1 Aver. Total Solids Total Solids Per Acre Gen.3/ Merit Rat. Chip4/ Color Early5/ Blight Reading Not Available Other Data General Note 2 2 4851 4953 94.5 93.6 15.8 15.1 T 1 1 4 307 328 290 307 good red colorgood red color 4 2.0 empty table cell empty table cell 3.0 Not Available Not Available Variety EARLY TO MEDIUM EARLY ND146-4R EARLY TO MEDIUM EARLY Norland MEDIUM TO LATE Neb. Al29-69-1 Neb. A71-72-1 MEDIUM TO LATE Neb. A219.70-3 MEDIUM TO LATE MN 8742 MEDIUM TO LATE MN 9319 MEDIUM TO LATE Wisc. 723 MEDIUM TO LATE Wisc. 726 MEDIUM TO LATE Wisc. 806R MEDIUM TO LATE La. 42-38 MEDIUM TO LATE AK 34-2 MEDIUM TO LATE TND 14-lRuss MEDIUM TO LATE Red Pontiac MEDIUM TO LATE Russet Burbank MEDIUM TO LATE Norchip MEDIUM TO LATE MN 8757 MEDIUM TO LATE Average 1/ 1-Very Early-Norland maturity; 2-Early-Irish Cobbler maturity; 3-Medium-Red Pontiac maturity; 4-Late-Katahdin 4.0 empty Not Available pointed tubers table cell 3.0 Not Available deep eye deep eye empty table 1.0 cell Not Available not empty table 2.0 cell Not Available good typo-blocky 1.5 1 Not Available irregularirregular empty table 2.0 cell empty table Available deep eye deep eye 3.0 Not cell Not Available good tuber color 3 3.5 Not Available deep eye deep eye cell 3.0 empty table smooth; small 5 2.5 Not Available Not Available very smooth; smal 2 2.0 Not Available deep eye deep eye cell 4.0 empty table cell 4.0 Not Available irregularirregular empty table cell 1.5 empty table Not Available rough; small size cell 3.0 empty table deep eye deep eye Not Available 2.6Not Available empty table cell 8170 7151 5735 5761 4284 7084 6109 7877 8531 3968 4309 10619 8676 5649 6731 6496 96.4 88.9 96.9 93.1 96.2 93.8 95.1 95.3 96.2 91.9 94.2 97.4 87.8 90.9 97.7 94.0 1 0 T 0 T T 1 T 1 0 1 0 0 T empty table cell 4 0 4 0 2 3 4 3 4 0 5 0 0 3 empty table cell 444 404 324 333 238 356 307 445 449 248 258 621 436 307 426 367 18.4 17.7 17.7 17.3 18.0 19.9 19.9 17.7 19.0 16.0 16.7 17.1 19.9 18.4 15.8 17.7 428 359 314 310 229 334 292 424 432 228 243 605 383 279 416 345 5 4 3 3 3 4 4 4 4 2 3 4 5 3 3 3.6 empty table cell uniform uniform tuber shape irregular tuber shape irregular good tuber color smooth; small very smooth; smal rough; small size empty table cell pointed tubers not good typo-blocky 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, super­ ficial; 2. Larger, superficial; 3. Larger, rough pustules; 4. Larger pustules, shallow holes; 5. Very large pustules, deep hole. 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 or Agtron. 5/ Early blight reading (1-5); 1 - very susceptible; 5 - highly resistant. Table 2. The percent external and internal defects of several varieties entered in the 1980 North Central Potato Variety Trial. Normal Tubers (5) % 96 96 Growth Cracks % Second Growth % Sun Green % Total (4) Tubers Free of External Defects % Hollow Heart Internal Necrosis Vascular Discoloration % 2 0 % 4 4 Scab (3) % % 0 0 4 0 0 26 0 2 0 4 98 0 94 0 0 Variety EARLY TO MEDIUM EARLY ND146-4R EARLY TO MEDIUM EARLY Norland MEDIUM TO LATE 0 0 74 Neb. A129-69-1 Neb. A71-72-1 10 0 MEDIUM TO LATE 0 90 Neb. A219-70-3 MEDIUM TO LATE 0 0 100 MN 8742 MEDIUM TO LATE 2 0 94 MN 8757 8 4 MEDIUM TO LATE 86 0 MN 9319 MEDIUM TO LATE 4 92 4 Wisc. 723 MEDIUM TO LATE 2 2 0 94 Wisc. 726 6 0 MEDIUM TO LATE 0 92 14 Wisc. 806R MEDIUM TO LATE 2 0 82 La. 42-38 MEDIUM TO LATE 2 6 0 92 AK 34-2 _8 MEDIUM TO LATE 88 2 0 TND 14-lRuss MEDIUM TO LATE 2 0 94 0 Red Pontiac MEDIUM TO LATE 14 2 0 84 0 Russet Burbank MEDIUM TO LATE 6 0 0 94 Norchip MEDIUM TO LATE 0 0 4 96 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 0 4 0 0 2 0 2 2 2 0 2 4 0 0 20 6 2 16 6 22 18 12 0 4 6 4 16 0 6 4 10 0 2 0 0 0 2 4 4 6 0 2 6 0 76 84 98 82 90 78 82 86 94 90 84 96 80 94 92 0 0 0 0 4 0 0 0 2 2 4 0 2 0 2 0 to count tubers with any amount of scab in this category. 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 of internal defects. Weed Control in Potatoes William Meggitt and Richard Chase Dept. of Crop and Soil Sciences Herbicide treatments for weed control are shown in Table 1. Appli­ cations in 1980 all provided complete control of annual broadleaved and grass weeds. The sprayule or dry flowable formulation of met- tribuzin (Sencor/Sexone) performed equal to the flowable (4L) formu­ lation. The major weeds in the test area were barnyardgrass and lambsquarter. Yields in Table 1 show no differences in yields with the exceptions of the postemergence applications of KK-80 and Hoelon. Yields, were quite variable. Prowl and Dual when registered offer addition chemicals for preemergence control of annual grass. POTATO YIELDS, 1980, MONTCALM FARM Treatment (Delay Pre) (PPI) (Delay Pre) (PPI) (Delay Pre) (PPI) (PPI) (Delay Pre) (Post) (Pre) (Pre) (Pre) (Pre) 1. Eptam + Sencor Sprayule 2. Eptam 4- Lexone DF 3. Eptam + Lorox 4. Eptam + Sencor 4 + Sen Sprayule 5. Lasso + Sen/Lexone 4 (Delay Pre) 6. Lasso + Sen/Sprayule (Delay Pre) 7. Dual + Sen/Lexone 4 (Delay Pre) 8. Dual + Sen/Sprayule (Delay Pre) 9. Lasso + Sencor (Pre) 10 Dual + Sencor (Pre) 11. Lasso + Lorox (Delay Pre) (Pre) 12. Dual + Lorox (Delay Pre) (Pre) 13. Prowl + Lorox (Delay Pre) (Pre) 14. Prowl + Sen/Sprayule (Delay Pre) (Pre) 15. Lasso + DPX 6573 (Delay Pre) (Pre) 16. Surflan + Sen/Lexone 4 (Delay Pre) (Pre) 17. Sen + Lasso + Sencor + Lasso (Pre) (Post) 18. Sencor + Hoelon + oc (Delay Pre) (Post) 19. Sencor + KK80 + oc (Delay Pre) (Post) 20. Sencor + BASF 9052 + oc (Delay Pre) (Post) 21. Lasso + Sencor (Hill before spraying Delay Pre) 22. Dual + Sencor (Hill before spraying Delay Pre) 23. NO TREATMENT Rate Lb/A 4 + 1/2 4 + 1/2 4+1 Yield Cwt/A 268 292 256 Specific Gravity 1.078 1.079 1.077 4 + 1/2 + 1/4 2 + 1/2 2 + 1/2 2 + 1/2 2 + 1/2 2 + 1/2 2 + 1/2 2 + 1 2 + 1 1 + 1 1 + 1/2 2 + 1 1 + 1/2 1/2 + 2 + (1/4 + 1) 1/2 + 1 + 1 qt 1/2 + 1 + 1 qt 1/2 + 1/2 + 1 qt 2 + 1/2 2 + 1/2 empty table cell 284 273 254 298 264 293 286 298 281 257 277 284 286 262 237 197 294 274 267 103 1.080 1.079 1.078 1.079 1.080 1.077 1.078 1.079 1.079 1.081 1.080 1.077 1.076 1.078 1.077 1.079 1.079 1.076 1.079 1.077 NITROGEN STUDIES WITH POTATOES M. L. Vitosh Department of Crop and Soil Sciences Introduction Present nitrogen recommendations by Michigan State University have been developed from research at the Montcalm Research Farm. Very little recent in­ formation is available on short season varieties such as those grown for early market in Bay County. A similar situation occurs for late potatoes grown on organic soils. The objective of these two studies was to determine the optimum rate of nitrogen for short season varieties grown in Bay county and for Kennebecs grown on organic soil. Procedure A site was selected on organic soil on the Jim Shoemaker farm in Allegan County to evaluate the need for additional sidedress nitrogen. A basic ferti­ lizer treatment consisting of 30 gallon of 14-32-0 was applied at planting time plus 150 lbs of 46-0-0 applied in early June. The basic rate of nitrogen was approximately 111 lbs per acre. The sidedress nitrogen treatments were applied on June 24, 1980 using ammonium nitrate (34-0-0). The treatments were 0, 60, 120 and 180 to make a total of 111, 171, 231 and 291 lbs N/A, respectively. Yields were harvested with the MSU Plot Harvestor on September 26, 1980. The second study was established at the Meyers Farm in Bay County. Six varieties (Belrus, Atlantic, Oceania, Onaway, Superior and B 7516-9) were hand planted on May 2, 1980. The experimental design was a split plot where nitrogen levels (100, 150 and 200) were whole plots and varieties were subplot treatments. The nitrogen was topdressed as ammonium nitrate (34-0-0). A starter fertilizer consisting of 700 lbs 6-24-24 was put down with the farmers planter when the seed rows were opened. Ammonium nitrate was applied at rates of 58, 108 and 158 lbs N/A to bring the total N applied to 100, 150 and 200 lbs/A on May 25th. The plots were harvested on August 12, 1980. Tubers were weighed, sized and sampled for specific gravity determination. Results The yield, size distribution and specific gravity of Kennebec’s grown in Allegan County are shown in Table 1. Nitrogen additions increase the yield of large tubers (>3 1/ 4 inches diameter) however this resulted in fewer medium size tubers at the highest rate of N (180 lb N/A). The highest rate of N resulted in the lowest total yield and the lowest specific gravity. Although late blight on tubers was not specifically evaluated there appeared to be a higher incidence on tubers receiving the highest rate of N. The data from the second study are found in Tables 2-4. The total yield and yield of U.S. No. 1 tubers for each variety and N rate are similar. One hundred lbs of N in general gave the largest yield for all varieties. The 150 lb N rate usually produced a lower yield, however the 200 lb N rate in some instances gave a larger yield for some varieties. Specific gravity was lowest with 200 lbs N/A. Not all varieties responded in this manner but Belrus and Superior showed most of the reduction. Onaway and Atlantic were the best yield­ ing varieties. Specific gravity of Atlantic was far superior to Onaway. Summary The present recommendation of 120 lbs of N for late potatoes on organic soils and 150-180 lbs of N per acre on mineral soils for early potatoes appears to be very adequate. Additional rates of N did not result in larger yields in these studies but did lower quality as measured by tuber specific gravity. Table 1. Effect of sidedress nitrogen on yield, tuber size and specific gravity of Kennebec potatoes grown on organic soil. Sidedress Nitrogen2/ lb/A 0 60 120 180 Over 3 1/4"cwt/A Size Distribution 2-3 1/4" Size Distribution Under 2" cwt/A Size Distribution Total Yieldcwt/A 24.3a1/ 32.6 bc 28.6ab 35.1 c cwt/A 243.2 b 231.5 b 246.0 b 205.4a 17.8a 20.0ab 22.8 b 21.8 b 285 b 284 b 297 b 262a Specific Gravity -g/cc- 1.069 b 1.067ab 1.067ab 1.066a 1/Values with a column followed by different letters are significantly different as 2/ Basic rate of nitrogen at planting was lll lbs/A. Sidedress nitrogen was applied determined by the Duncans Multiple Range test at the .05% confidence level. June 24, 1980 as ammonium nitrate. Table 2. Total yield as affected by nitrogen fertilizer with six potato varieties grown in Bay County (Meyers Farm). Variety Belrus Atlantic Oceania Onaway Superior B7516-9 Total Nitrogen Rate (lbs N/A) 1/100cwt/A 275 426 413 450 374 415 Total Nitrogen Rate (lbs N/A) Total Nitrogen Rate 1/ 150cwt/A (lbs N/A) 1/ 200 cwt/A 258 410 391 396 364 367 269 418 384 469 374 366 Total Nitrogen Rate (lbs N/A) 1/Meancwt/A 267a2/ 418cd 396bc 438d 371b 383b 392b empty table cell Bean 1/700 lbs 6-24-24 was applied at planting to supply 42 bls of N. The additio­ 380ab 364a nal N was topdressed on May 29 at emergence. 2/Values within a column followed by different letters are significantly differ­ ent (P=.05) as determined by the Duncans Multiple Range test. Table 3. Yield of U.S. No. 1 tubers as affected by nitrogen fertilizer with six potato varieties grown in Bay County (Meyers Farm). Variety Belrus Atlantic Oceania Onaway Superior B 7516-9 Mean Total Nitrogen Rate (lbs N/A)1/100cwt/A 215 383 377 415 353 375 353b Total Nitrogen Rate (lbs N/A)1/ 150cwt/A Total Nitrogen Rate (lbs N/A)1/ 200 cwt/A 199 374 364 364 336 330 328a 213 387 364 425 353 317 343ab Total Nitrogen Rate (lbs N/A)1/Meancwt/A 209a 381cd 368b 40ld 347b 341b empty table cell 1/700 lbs 6-24-24 was applied at planting to supply 42 lbs of N. The additional 2/Value within a column followed by different letters are significantly different N was topdressed on May 29 at emergence. (P= .05) as determined by the Duncans Multiple Range test. Table 4. Specific gravity of tubers as affected by nitrogen fertilizer from six potato varieties grown in Bay County (Meyers Farm). Variety Total Nitrogen Rate (lbs N/A)1/100g/cc Total Nitrogen Rate (lbs N/A)1/ 150 g/cc Total Nitrogen Rate (lbs N/A)1/ 20 0 g/cc Total Nitrogen Rate (lbs N/A)1/Meang/cc 1.067c2/ Belrus 1.063 Atlantic 1.076 1.076d Oceania 1.057a 1.057 1.059ab 1.058 Onaway 1.063b 1.061 Superior 1.059ab B 7516-9 1.058 1.062a empty table cell Mean 1/700 lbs of 6-24-24 was applied at planting to supply 42 lbs of N. The 1.065 1.076 1.057 1.060 1.065 1.059 1.064ab 1.074 1.077 1.057 1.058 1.062 1.059 1.065b additional N was topdressed on May 29 at emergence. 2/Values with a column followed by different letters are significantly different (P=.05) as determined by the Duncans Multiple Range test. PHOSPHORUS STUDY WITH RUSSET BURBANKS M. L. Vitosh. Department of Crop and Soil Science Introduction Phosphorus studies at the Montcalm Research Farm in 1979 showed that phos­ phorus fertilizer gave a very significant increase in yield of potatoes even though Bray P1 soil tests were in excess of 400 lbs per acre. Corn rarely responds to phosphorus when the soil test exceeds 60 lbs per acre. The objectives of this study were to look at potato response to two phosphorus sources (di­ ammonium phosphate and monoammonium phosphate), three phosphorus rates (0, 50, and 150 lbs P205 per acre) two methods of application (band vs. broadcast). Procedure The experiment was established on a Montcalm-McBride sandy loam soil at the Montcalm Research Farm. Soil samples were taken from each plot prior to applying any fertilizer. The soil test results are shown in Table 1. The data indicate that the soil was quite uniform and no difference in values existed prior to the application of fertilizer. Soil test phosphorus ranged from 472-509 lb per acre which was similar to the area studied in 1979. The experimental design was a randomized complete block with eight treat­ ments and four replications. Russet Burbank seed was planted on May 13, 1980, after the broadcast phosphorus treatments were applied and disked in. Urea (46-0-0) and potash (0-0-60) were blended with diammonium phosphate (18-46-0) and monoammoniumphosphate (13-52-0) to balance the N and K in each treatment. All plots received 100 lbs N and K20 per acre either banded or braodcast applied as was the phosphorus carrier. Potato petioles were sampled on June 30 and July 21 for analysis of P and other elements. The samples were oven dried, ground and analyzed by a plasma spectrophotometer. Tubers were harvested on October 7th, sized, weighed and sampled for specific gravity determination. Results The elemental composition of potato petioles sampled on June 30th are re­ ported in Table 2. Phosphorus and manganese were the only elements significantly affected by the phosphorus treatments at this early sampling. The 150 lbs P205 banded, resulted in significantly higher concentrations of both P and Mn than 150 lbs P205 broadcast or 50 lbs P205 banded. The broadcast treatments resulted in similar concentration of P and Mn as the 0 phosphorus treatments. No differ­ ences between phosphorus sources was observed in these petiole samples. Potato petiole analysis for the July 21 sample date are shown in Table 3. Results for P and Mn were very similar to the first sampling where only the 150 lb rate banded significantly increased the concentration of these elements in the petioles. In addition boron was found to be significantly affected by the treatments, however the differences are small and not consistent enough to be explained. All values except three zinc and one copper value are above the critical level as described in Extension Bulletin E-486. The critical values for Zn and copper are 30 and 7 ppm, respectively. All values for the June 30 samples were well above the critical values and it is unlekely these elements would be classified as deficient. Tuber yield, size and quality are reported in Table 4. Only total yield was significantly affected by the treatments. Only the last treatment (a 0 P treatment) was found to yield significantly less than all other treatments in­ cluding treatment one which was also a 0 P treatment. Table 1 does not indicate any significant difference between soil test P in plots of these treatments thus given no clue as to why these plots responded differently. Phosphorus source and placement had no significant effect on yield, size or specific gravity. Summary The results in 1980 were not as dramatic as 1979 showing only a small but inconsistent response to phosphorus fertilizer. The plant analysis data indicate that the rate of banded P has a greater influence on P concentration in the plant than source of P. Fifty lbs of P205 landed at planting on soils similar to this sandy loam should be sufficient for optimum yields Table 1. Soil tests from the experimental area prior to the application of the phosphorus fertilizer treatments. Soil Test P lb/A Soil Test K Soil Test Ca lb/A Mg lb/A Soil Test Source Phosphorus Phosphorus Placement Phosphorus Rate Soil TestpH -lb P2O5/A- - Band Band Band Band Broadcast Broadcast - None 18-46-0 13-52-0 18-46-0 13-52-0 18-46-0 13-52-0 None LSD(.05)empty table cell 0 50 50 150 150 150 150 0 empty table cell 7.0 7.1 7.0 7.1 7.1 6.8 6.8 7.0 NS 497 509 472 493 496 482 487 431 NS lb/A 1045 1087 1087 1088 1088 1109 1045 1088 NS 350 343 347 341 320 393 341 345 NS 216 228 228 240 208 210 193 224 NS Table 2. Elemental composition of potato petioles sampled June 30, 1980 as affected by rate source and placement of phosphorus fertilizer. K Ca% Elements Elements Mg% Elements Znppm Elements Elements Elements Mnppm Cuppm Feppm Elements Elements Moppm Alppm Elements Phosphorus Source Phosphorus Placement Phosphorus Rate3/ -lb P205/A- 7 None 18-46-01/ 13-52-02/ 18-46-0 13-52-0 18-46-0 13-52-0 None LSD (.05)empty table cell Band4/ Band Band Band Broadcast5/ Broadcast - 0 50 50 150 150 150 150 - empty table cell Elements P % % 10.6 .22 .31 .30 .47 .48 .29 .27 .25 .10 9.8 9.6 9.6 11.9 10.5 10.1 10.1 NS 1.11 1.10 .97 .93 1.22 1.13 1.03 1.06 NS .65 .62 .60 .60 .71 .61 .60 .62 NS 44 41 40 42 46 42 40 40 NS 64 89 64 102 119 43 36 38 35 16 8 19 11 16 8 13 10 NS Elements B ppm 25 75 24 24 24 28 26 26 27 NS 68 79 69 78 78 81 80 NS 4 4 4 4 4 4 4 4 NS 162 163 192 183 159 176 183 164 NS 1/Diammonium phosphate 2/Monoammonium phosphate 3/Diammonium and monoammonium phosphates were blended with urea and potash to supply 100 lbs of N and K20 at planting for all plots. In addition 120 lbs of N was sidedress at hilling time. 4/Banded in two bands 2 inches to the side and 2 inches below the seed piece. 5/Disked in after plowing and before planting. Table 3. Elemental composition of potato petioles sampled July 21, 1980 as affected by rate, source and placement of phosphorus fertilizer. Phosphorus Source Phosphorus Placement Phosphorus Rate3/ Elements P % - None 18-46-01/ 13-52-02/ Band Band Band Band 18-46-0 13-52-0 18-46-0 13-52-0 None LSD (.05) empty table Broadcast Broadcast - cell .27 .27 .28 -lb P205/A- 0 50 50 150 150 150 150 - .39 .39 .33 .29 .29 empty table cell .11 Elements K % 8.0 6.9 7.0 7.3 7.4 7.8 8.7 8.7 NS Elements Ca % Mg % Elements ElementsMn ppm Elements Zn ppm Elements Cu ppm .72 .58 .63 .75 .77 .71 .89 .90 NS .61 .52 .54 .68 .63 .58 .72 .72 NS 37 34 31 29 32 32 29 27 NS 89 122 103 125 164 85 90 53 48 9 9 7 8 6 7 9 7 NS Element s B ppm 28 27 26 26 27 27 29 28 2 Elements Fe ppm 55 57 54 53 57 53 56 56 NS ElementsMo ppm 3 3 3 3 3 3 3 3 NS Elements Al ppm 48 83 48 45 50 53 45 66 NS 1/Diammonium phosphate 2/Monoammonium phosphate 3/Diammonium and monoammonium phosphates were blended with urea and potash to supply 100 lbs of N and K20 at planting for all plots. In addition 120 lbs of N was sidedressed at hilling time. 4/Banded in two bands 2 inches to the side and 2 inches below the seed piece. 5/Disked in after plowing and before planting. Table 4. Effect of phosphorus fertilizer source, placement and rate of application on tuber shape, size, yield and specific gravity of Russet Burbank potatoes. Phosphorus Source Phosphorus Placement Phosphorus Rate3/ Off Typecwt/A Over 10 ozcwt/A A Sizecwt/A B Sizecwt/A Total Yieldcwt/A Specific Gravity g/cc 371 383 376 380 373 377 369 337 25 1.077 1.080 1.079 1.078 1.079 1.079 1.080 1.077 NS -lb P205/A- 0 50 50 150 150 150 150 0 - 4/ Band Band Band Band Broadcast5/ Broadcast - None 18-46-01/ 13-52-02/ 18-46-0 13-52-0 18-46-0 13-52-0 None LSD (.05) empty table cell empty table cell 55 60 58 54 67 61 64 60 NS 77 73 83 76 71 72 76 64 NS 189 200 187 194 182 193 182 162 NS 50 50 49 57 53 52 48 51 NS 1/Diammonium phosphate 2/Monoammonium phosphate 3/Diammonium and monoammonium phosphates were blended with urea and potash to supply 100 lbs of N and K20 at planting for all plots. In addition 120 lbs of N was sidedressed at hilling time. 4/Banded in two bands 2 inches to the side and 2 inches below the seed piece. 5/Disked in after plowing and before planting. THE INFLUENCE OF SELECTED PRODUCTION MANAGEMENT INPUTS ON THE YIELD, QUALITY, AND STORABILITY OF POTATOES M. L. Vitosh, G. W. bird, E. Grafius, R. W. Chase, H. C. Olsen Departments of Crop and Soil Sciences and Entomology Previous experiments investigating the response of potatoes to nitrogen and phosphorus have demonstrated that the use of nematicide is important for optimal use of nutrient inputs when Pratylenchus penetrans is present. The 1980 Integrated experiment dealt with the effect of potassium and pest control inputs on the yield, quality and storability of Superior. Our objectives 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. Methods Seed pieces were planted on May 12, 1980 (degree day base 10 C [DD10 = 139]) 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 K2O/A were subjected to three different pest control treatments: Temik 15G 3.0 lbs. a.i./A, Terraclor 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. T errachlor 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 determined by sampling at planting and every two weeks thereafter. Colletotrichum spp., Fusarium spp., Rhizoctonia spp., and Verticillium spp. were monitored three times during the growing season: July 16, 28 and Aug. 12 (DD10 = 1049, 1296, 1580, respectively). 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. RESULTS AND CONCLUSIONS Table 1 is a summary of the yield and specific gravity data. The amount of oversized tubers was significantly (P = 0.05) increased by Temik and again by potassium inputs within the Temik treatment. The temik treated plants were able to utilize higher potassium inputs than the non-Temik plants and marketable tuber yields increased incrementally with increasing potassium. Without nematode control (check and Terraclor) there were no yield increases above 50 lbs K2O/A. Only the plots treated with 150 lbs K20/A plus Temik had significantly higher (P = 0.05) production of A sized tubers. There was no significant (P = 0.05) difference in the yields of B sized tubers. Either the nematode control and/or other properties of Temik allowed optimal use of the potassium inputs not realized in the check or Terraclor treatments. It is probable that the root damage cuased by high nematode densities reduced the root system’s efficiency to adsorb and transport potassium resulting in reduced ruber production. There were no significant (P = 0.05) differences relating the inputs and specific gravities, though there was a tendency for reduced specific gravity with the highest potassium input and with Temik. Soil samples were taken from every plot just prior to applying the broadcast K fertilizer. Good soil test uniformity was observed for all treatments except soil pH as indicated by the non-significant (NS) LSD tests (See Table 2). Soil pH, however, did not vary more than 0.3 for all treatments compared. Exchange­ able K varied from 300 to 403 and yet these differences were not measured as signicantly different indicating that considerable variability exists for this element. The range for K in the entire experimental area was 244 to 541. Using the average value for the entire area (333 lb K/A) the maximum recommendation for a yield of 450—550 cwt/A would be 100 lb K2O/A. A zero K recommendation would be given for any yield level of less than 350 cwt/A. Potato petiole samples were taken June 30 and three weeks later on July 21. Analysis for the first sampling are showing in Table 3. Only K was signifi­ cantly affected by the treatments. In general, K concentrations in the potato petiole were directly related to the rate of K fertilizer applied. Temik and Terrachlor had no effect on K concentration in the petioles. The second sampling data are presented in Table 4. In addition to K, Ca and Mg were also significantly affected by the treatments. In general, increasing the K content of the potato petioles decreased the Ca and Mg levels. Many of the elements (NO3, P, K, Zn and Mo) tended to increase with the second sampling while Ca, Mg, Mn, Fe and Al decreased. Copper was found to be highly variable indicating the possibility of problems with analyzing petioles for this element. Normal or sufficient ranges for potato petioles from recently matured leaves sampled in mid-season have been reported as follows: P = .18 - .22 K = 6.0 - 9.0 Ca = .36 - .50 Mg = .17 - .22 Mn = 30 - 200 Fe = 30 + B = 14 - 40 Cu = 7 - 30 Zn = 30 - 100 From these sufficiency ranges, we find K in the petioles at the first sampling was below the 6.0% critical level except where 150 lb K20 per acre was broad­ cast. On the second sampling date, all K values were above the critical 6.0% level. I would conclude that some K banded at planting time would probably have increased the early uptake of K and may have resulted in better plant gorwth. Zinc values for the first sampling also appear to be below the suggested critical level of 30 ppm. The second sampling data, however, shows that nearly all Zn levels were above the 30 ppm. In summary, it appears that some K banded at planting may be beneficial and would have resulted in higher K levels in potato petioles sampled in late June. Since broadcast K did not result in increased yield, we can only speculate what may have happened if K had been banded. A general trend toward a yield increase due to applied K was observed when Temik was included. The largest yield was obtained with 150 lbs K2O and Temik. Temik and Terrachlor did not significantly affect the chemical composition of potato petioles. Previous studies have shown that Mn content was decreased with use of Temik. Yields for this experiment were somewhat lower than anticipated. At this yield level, the MSU recommendation would be zero lbs K2O. Thus, it would appear that the present K recommendations are adequate. The experiment was established on May 12, but significant (P = 0.05) P. penetrans control did not occur until the July 8 sampling (see Fig. 5). At this time, there were many juveniles in the check and Terraclor roots but none in the Temik roots. There was no significant (P - 0.05) influence by potassium levels or Terraclor on P. penetrans populations. The relatively late nematode control by Temik is probably due to a lack of soil moisture early in the growing season, limiting Temik’s diffusion through the soil and root uptake. Due to the heavy spray schedule, Colorado potato beetles were the only insects of any consequence. The first brook of Colorado potato beetle adults were present by May 27 and through July 1. The second brood began emerging slightly before the July 15 sampling and was present at harvest, August 19. No beetle adults were active in the Temik treatments until July 22. Egg masses laid by the first-brood adults were present on the non-Temik plots most of the growing season. The egg masses from the second-brood adults were first noted on August 4 and were present on all treatments. Larvae were present on the non-Temik plants from June 17 through July 22 and then again on August 4. No larvae were detected on the Temik treatment. The spray schedule was adequate to control significant damage to the non-Temik treatments. Terraclor was used to reduce soil-borne fungi populations. Early dying symptoms were noted by mid-July and the laboratory procedures concurred that Verticillium was a factor. There were no differences in infection levels due to the potassium treatments. The earliness of Verticillium infection is considered by some researchers to be the most important factor for predicting yield loss from Verticillium. The earlier the infection, the greater the yield loss. Our late sampling plus the lack of early-season nematode control may have caused our limited success in detecting treatment effects on Verticillium. Rhizoctonia. Fusarium, and Colletotrichum were also identified from the samples. There was no noticeable difference in their infection levels due to the treatments. By August 12, percent infection of Rhizoctonia. Fusarium and Colletotrichum was 40, 40 and 90, respectively. Based on our sampling, Terraclor did little to limit fungal infection. SUMMARY By integrating pest control measures and potassium inputs, we were able to more fully understand the interactions of nutrient inputs and pest influences. When nematodes were controlled with Temik 15G, there was a significant (P = 0.05) yield increase of oversized tubers plus a greater significant (P = 0.05) yield increase of oversized tubers from the potassium inputs. The production of market­ able tubers was significantly (P = 0.05) increased with Temik 15G. The potassium inputs had no noticeable effect on the nematode, fungus or insect population densities. The results indicate that with P. penetrans present, Temik 15G was necessary to optimize potassium inputs. The pest control treatments had no effect on potassium concentration in the plants. It appears that some potassium banded at planting was necessary to obtain proper early season potassium levels for good plant growth. TABLE 1 Influence of Selected Management Practices on Final Tuber Yield and Specific Gravity of Superior empty table cell 1980 Tuber Yields (CWT/A) A Tuber Yields (CWT/A) Jumbo Tuber Yields (CWT/A) Tuber Yields (CWT/A) (A+Jumbo) B specific Gravity 1. 2. 3. 4. 5. 6. 7. 8. 9. 0 lbs K 2 0/A - check 50 lbs K 2 0/A - check 150 lbs K 2 0/A - check 0 lbs K20/A - Temik1 2 50 lbs K20/a - Temik 150 lbs K20/A - Temik 0 lbs K 2 0/A - Terraclor3 50 lbs K20/A - Terraclor 150 lbs K20/A - Terraclor 228.24a 236.84a 234.86a 269.74bc 273.58bc 294.96c 233.30a 242.40ba 241.92ba 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 ' 1 Treatment 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. Soil tests from the experimental area prior to the application of the potassium fertilizer and chemical treatment. Potassium -lb K29/A- 0 50 150 0 50 150 0 50 150 LSD (.05) Chemical Soil Test pH Soil Test K P lbs/A Soil Test lbs/A Soil Test Ca lbs/A Soil Test Mg lbs/A Control Control Control Temik Temik Temik Terrachlor Terrachlor Terrachlor empty table cell 6.9 6.8 7.0 7.1 7.0 6.8 7.0 7.0 6.9 0.2 544 539 518 505 546 559 511 522 510 NS 310 315 340 300 403 341 325 330 334 NS 1258 1067 1259 1109 1280 1237 1130 1237 1216 NS 237 205 254 228 237 241 211 252 241 NS Table 3. Elemental composition of potato petioles sampled on June 30, 1980 as affected by potassium fertilizer and chemical treatments. Treatment Treatment Potassium1/ -lb K20/A- Elements Ca % Elements Mg % Elements Zn ppm Elements Mn ppm 1.38 1.44 1.51 1.37 1.43 1.28 1.46 1.44 1.45 NS 1.14 1.08 1.08 1.23 1.01 1.03 1.21 1.24 1.05 NS 29 26 27 25 25 23 27 24 25 NS 400 461 573 354 455 424 394 394 539 NS Elements Cu ppm 67 12 24 24 34 39 29 44 37 NS Elements Elements Fe ppm Elements Mo ppm Elements Al ppm B ppm 37 34 39 35 36 33 37 34 35 NS 120 112 120 94 114 102 112 119 113 NS 9 9 9 9 9 9 9 9 9 NS 257 187 214 145 227 164 191 197 210 NS 0 50 150 0 50 150 0 50 150 Chemical Control2/ Control Control 3/ Temik Temik Temik no3 Elements PPm 21,921 19,559 20,215 21,914 21,109 20,308 Terrachlor4/ Terrachlor Terrachlor empty table cell 19,988 19,013 20,180 Elements P % .23 .23 .22 .30 .21 .30 .21 .23 .23 NS Elements K % 5.15 5.68 6.43 5.07 6.48 6.32 5.56 5.98 6.64 0.82 NS LSD (.05) 1/Broadcast and disked in before planting 2/Foliar pesticides to control insects and disease 3/Banded with the fertilizer at 3 lb a.i. per acre 4/Broadcast spray and disked in before planting. Table 4. Elemental composition of potato petioles sampled on July 21, 1980 as affected by potassium fertilizer and chemical treatments. Treatment Potassium1/ -lb K2O/A- 0 50 150 0 50 150 0 50 150 LSD (.05) Treatment Chemical Control2/ Control Control Temik3/ Temik Temik 4/ Terrachlor Terrachlor Terrachlor empty table cell Elements NO3 ppm 29,234 31,318 30,074 31,274 28,917 29,495 30,373 33,729 28,787 NS P % K % Elements Elements Elements Ca Mg% Elements Elements Znppm Elements Mn ppm % 1.21 1.08 .94 1.17 1.01 1.19 1.16 1.16 1.05 .16 6.28 6.48 6.98 6.37 7.93 8.03 7.62 7.10 7.88 1.20 .85 .74 .55 .90 .54 .82 .79 .85 .64 .18 .39 .36 .35 .38 .37 .39 .35 .38 .39 NS 28 33 38 28 37 31 37 32 39 NS 306 261 247 267 229 240 267 218 257 NS ElementsCu ppm 29 28 40 11 40 47 12 23 41 NS Elements Feppm Moppm Elements Elements Alppm Element s B ppm 28 27 25 29 30 31 32 27 32 NS 107 110 97 111 113 132 120 98 137 NS 7 7 7 8 7 8 8 7 8 NS 299 408 393 331 375 466 421 282 467 NS 1/Broadcast and disked in before planting 2/Foliar pesticides to control insects and disease 3/Banded with the fertilizer at 3 lb a.i. per acre 4/Broadcast spray and disked in before planting FIGURE 5 POPULATION DYNAMICS OF P. PENETRANS ON SUPERIOR THE RELATIONSHIP OF VARIETY AND NITROGEN TO YIELD, SPECIFIC GRAVITY, SUCROSE AND PROCESSING QUALITY J.N. Cash, C. Senterre and M.R. McLellan Department of Food Science and Human Nutrition R.W. Chase and R.B. Kitchen Department of Crop and Soil Sciences Introduction Although physical maturity and tuber size are important because they determine crop yield, one of the major factors affecting the final quality of processed potato products, especially chips, is the sugar content at harvest and the amount of reducing sugars which accumulate during storage. In a storage situation, the carbohydrate, sucrose, can be enzymatically converted to two, 6 carbon reducing sugars (glucose and fructose), which then react with amino acids during frying, to produce dark colored chips. Under these circumstances, it has been shown to be very important for potatoes being stored for chipping to have minimal sucrose levels when harvested and it is this factor which separates good processing potatoes from poor processors. Since carbohydrate content is so important for finished product quality, it was felt that monitoring the sugar changes during growth of tubers could be use­ ful in predicting harvest maturity, however, these changes may be influenced by a number of factors, including, variety, growing conditions, soil fertility and stress conditions. The present, two year study, has been designed to incorporate some of these factors in order to determine their effects on sucrose content during tuber growth. A second, and equally important objective, has been to obtain sucrose data for potatoes grown in Michigan. Procedure Six varieties, Atlantic, Belchip, Denali, Monona, Norchip and Russet Burbank were grown at two levels of nitrogen, 170 and 240 lbs/A. Fertilizer applied was 200 lbs/A 0-0-60 at plowdown, 500 lbs/A of 19-19-19 at planting. Sidedress nitrogen (150 lbs/A 46-0-0) was applied to the high fertility plots as a side­ dress when the plants were approximately 10 inches tall. A one year old stand of alfalfa was plowed down. The varieties and fertility were arranged in a randomized block with 4 replications. Russet Burbank and Norchip were planted at 10 inches and the others at 7 inches. Six plantings of the entire experiment were made on May 6 so variable harvests could be made at approximately 2 week intervals. Actual harvests were July 31, August 14, 27, September 16 and October 1 and yields, size distribution, specific gravity and chip color were determined. Samples were also collected for sucrose and carbohydrate analysis. Samples from the September 16 harvest were placed in 53F and 45F storages for chip processing in January and February respectively. Soil temperatures at the 4 and 10 inch depths were monitored during the total harvest period. Field Results The marketable yield and specific gravity response for each variety appears in Figures 1-6. There was very little total yield response to the higher level of nitrogen suggesting that some factor other than nitrogen limits a further increase in yield. This was particularly true for Norchip, Belchip and Atlantic. Monona, Russet Burbank and Denali did show a yield increase at the higher level. Denali, Belchip and1 Russet Burbank are late maturing varieties and did not reach their optimum yields until late September whereas Norchip Monona and Atlantic had a much lower bulking rate late in the season as evidenced by the leveling off of their yield curves later in the season. Of particular interest is the development of specific gravity during the growing season. In nearly all varieties the higher level of nitrogen resulted in a lower specific gravity. This fact has been demonstrated on other varieties by other researchers. Monona, Norchip and Russet Burbank reached their maximum levels of specific gravity by the end of August followed by a slight decline. The above average rainfall during September may have added to the decline. Atlantic and Belchip reached their maximum level approximately 2 weeks later or by mid-September. Denali declined in mid-September and then increased again by October 1, however to only the same level attained by the end of August. Chipping tests were conducted at 1 and 4 days after harvest. For all varieties and all harvests, chip color was well within the acceptable color range. Soil temperatures at the 4 inch level ranged from a high of 74 to a low of 43. (Table 1) At the 10 inch level the range was from 71 to 50. As expected, the extremes at the 4 inch level were much greater than at the 10 inch depth. Table 1. The soil temperatures recorded at a 4 and 10 inch depth during the harvest period of August 14 - October 1. Montcalm Research Farm, 1980. Recording Period Aug. 14-21 Aug. 21-28 Aug. 28 - Sept. 5 Sept. 5-12 Sept. 12 - 19 Sept. 19 - 25 Sept. 25 - Oct. 1 4 inch High 4 inch 72 74 74 74 70 66 64 Low 59 62 62 55 49 48 43 High 10 inch 68 70 71 68 65 63 59 10 inch Low 62 64 64 60 55 55 50 Figure 3. The marketable yield and specific gravity of Denali grown at two nitrogen levels and harvested on different days after planting. Figure 4. The marketable yield_and specific gravity of Monona grown at two nitrogen levels and harvested on different days after planting. Figure 1. The marketable yield and specific gravity of Atlantic grown at two nitrogen levels and harvested on different days after planting. Figure 2. The marketable yield and specific gravity of Belchip grown at two nitrogen levels and harvested at different days after planting. Figure 5. The marketable yield and specific gravity of Norchip grown at two nitrogen levels and harvested on different days after planting. Figure 6. The marketable yield and specific gravity of Russet Burbank grown at two nitrogen levels and harvested on different days after planting. Carbohydrate Analysis Results Sugar changes were determined by a standard sucrose rating (SR) technique at each harvest date. Previous work, using the SR analysis for predicting storage stability, has indicated that an SR of 2.8 or less is desirable for good processing potatoes. All the varieties tested were below this level by July 31 (86 days after planting) but tubers were still small and specific gravity was very low at this point (see Figures 7 and 8). The SR values leveled off and did not change significantly after the July 31 harvest. As expected, chip color tended to follow the same trend with all cultivars producing chips that rated between 1 and 2 on the PC/SFA 5 code color scale (1 lightest - 5 darkest) by July 31. For the present study, use of the SR as an aid in predicting harvest maturity showed that there was a great deal of difference in sucrose contents between samples but all potatoes tested attained low sucrose levels several weeks before tuber size, specific gravity, and chip yield were at their maximum. Fluctuations in the SR occurred with environmental changes but in 1980 these changes were not statistically significant within cultivars or selections. Although the SR may be a valuable tool for planning storage regimes and predicting storage stability, it has not correlated well, under the conditions of the present study, with physical maturity parameters for predicting harvest maturity. In addition to the 6 cultivars included in the primary study, 27 cultivars and/or selections from the MSU variety trials were monitored for SR changes during the growing season. Results of these analyses are shown in Table 3 of the "1980 Potato Variety Evaluations" report. Figure 7 . Sucrose Rating (SR) and Specific Gravity (SG) of Atlantic, Belchip and Denali Potato Cultivars Grown at the Montcalm Farm in 1980. Figure 8 . Sucrose Rating (SR) and Specific Gravity (SG) of Monona, Norchip and Russet Burbank Potato Cultivars Grown at the Montcalm Farm in 1980. SOIL INSECT CONTROL STUDIES Arthur L. Wells Department of Entomology A plot to evaluate 20 different treatments including combinations of experimental and registered insecticides on soil insects was conducted at the Comden Farm adjacent to the Montcalm Experimental Farm in Montcalm County. The plot was located in a field which had been out of production several years and had become established with weeds and grasses. An early inspection of the area indicated that a low infestation of white grubs were present and could cause potential feeding damage to potato tubers. The treatments were applied in six replications of paired 25 foot rows in a randomized block design. The outside and every third plot was left untreated so the grub damage in each treated plot could be compared with an adjacent untreated plot. This plot layout was selected to assume adequate evaluation of the data since past research indicated that soil insects, especially white grubs, are seldom evenly distributed over an area. A space equivalent to one blank row was left between each plot. Ten foot alleys were left untreated between the ends of the replicated plots. The broadcast applications were distributed as granules or in water at the rate of 80 gallons per acre to the soil surface and incorporated immediately with a double disc to a depth of 6-8 inches. The treatments were made on May 15 and they were then planted the following day. The potato seed were planted with a two row planter leaving the seed furrow open for application of the band or in-furrow treatments after which they were covered with a disc and weeder attachment on a tractor. Whole Foundation Grade Sebago seed were used in the study. Recommended fertilizer and herbicide programs were followed early in the season and the plants in the alleys were removed so foliar fungicide and insecticide applications could be made as needed. A vine killer was applied prior to harvest to facilitate the use of the plot mechanical harvester. The plots were harvested on October 8-10 and placed in bags which were then labeled and taken to the research building at the Montcalm Research Farm. The "B" size tubers were sorted with the plot harvester and kept separate in the labeled bags. The tubers were sorted by size and examined for wireworm and white grub damage to determine the effects of the soil treatments on the yield and quality of the tubers. The damaged and undamaged tubers in each size class were counted and weighed for complete evaluation of the data. Samples of tubers from three replications of the treated plots were saved to determine their specific gravity. The plot data are presented in Table 1. Table 1. Yields and insect tuber damage data from soil insect research plot, Montcalm County, 1980 Material BASF 263 10G Untreated BASF 263 10G + Temik 15G Untreated Lorsban 4E Untreated Lorsban 4E + Temlk 15G Untreated Mocap 6 EC Untreated Mocap 6 EC + Temik 15G Untreated Mocap 6 EC + Furadan 10G Untreated SN-72129 5G Untreated SN-72129 5G Untreated SN-72129 5G + Temik 15G Untreated Dyfonate 4E Untreated Dyfonate 4E + Temik 15G Untreated Place­ ment Brdcst — Brdcst Band — Brdcst — Brdcst Band —- Brdcst -- Brdcst Band —- Brdcst Band —- Brdcst — Brdcst —- Brdcst Band — Brdcst —- Brdcst Band —- Lb ai/A 4 lb —- 4 lb 3 lb —- 4 lb —- 4 lb 3 lb —- 4 lb —- 4 lb 3 lb —- 4 lb 3 lb —- 4 lb — — 8 lb -- 4 lb 3 lb —- 4 lb —- 4 lb 3 lb —- Yield Cwt/A 398 384 391 333 350 350 393 342 341 350 386 362 382 329 333 317 357 352 386 326 356 356 378 316 Percent Tubers by size B's 9 8 Percent Tubers by size A’s 78 82 Percent Tubers by size Over 13 10 9 11 11 9 6 9 11 10 8 10 10 10 10 12 10 9 9 12 11 11 8 13 74 82 80 81 77 84 81 84 70 80 78 84 80 80 79 80 74 82 82 79 74 81 17 7 9 10 17 7 8 6 22 10 12 6 10 8 11 11 17 6 7 10 18 6 Spec. Grav. 1.066 —- 1.068 —- 1.063 — 1.068 —- 1.065 —- 1.067 — 1.065 —- 1.067 -- 1.063 -- 1.066 —- 1.067 —- 1.067 —- Total Tubers 2591 2551 2395 2423 2428 2370 2239 2349 2420 2492 2345 2535 2403 2415 2315 2191 2444 2397 2442 2515 2460 2484 2301 2458 Percent Good 98.1 98.9 Percent Damag 1.9 1.1 B's % of Tubers 23.2 20.8 B's % Damag 1.0 0.2 99.4 99.2 99.5 99.3 99.2 99.0 98.9 98.7 99.2 99.3 99.6 98.7 98.8 98.3 99.0 99.1 98.2 99.0 98.1 98.2 99.0 98.7 0.6 0.8 0.5 0.7 0.8 1.0 1.1 1.3 0.8 0.7 0.4 1.3 1.2 1.7 1.0 0.9 1.8 1.0 1.9 1.8 1.0 1.3 23.1 25.2 25.7 20.9 18.4 20.6 25.6 23.6 22.8 23.4 25.8 23.1 24.2 26.8 24.4 22.6 22.7 26.0 26.5 25.3 23.0 27.4 0.5 0.2 0.2 0.2 0.0 0.6 0.3 0.3 0.0 0.3 0.3 0.4 0.4 0.5 1.0 0.2 0.2 0.5 0.9 0.6 0.2 0.7 A's % of Tubers 72.0 75.4 A's % Damag 1.7 1.3 70.4 72.5 71.2 75.4 74.8 77.0 71.7 74.4 68.7 73.2 69.3 74.7 72.7 70.6 71.9 73.6 70.8 72.4 71.2 71.4 70.2 70.8 0.4 1.0 0.6 0.8 1.0 1.0 1.4 1.6 0.8 0.6 0.4 1.5 1.5 2.1 1.0 1.0 2.5 1.3 2.3 2.1 1.3 1.4 Oversize % of Tubers 4.6 3.7 Oversize % Damag 10.0 0.0 6.5 2.3 3.1 3.7 6.8 2.4 2.7 2.1 8.4 3.4 5.0 2.2 3.2 2.6 3.7 3.8 6.4 1.6 2.4 3.3 6.7 1.8 3.2 0.0 1.3 2.3 1.3 3.6 1.5 2.0 2.5 4.7 0.8 3.8 1.3 3.5 1.1 2.2 0.6 0.0 0.0 4.8 0.6 4.6 Total Tubers 2415 2392 2548 2381 2451 2402 Material Dyfonate 4E + Furadan 10G Untreated Diazinon 4E Untreated Diazinon 4B + Temik 15G Untreated Diazinon 4E + Furadan 10G Untreated Temik 15G Untreated Furadan 10G Untreated Untreated Untreated Untreated Untreated Place- ment Brdcst Band -- Brdcst -- Brdcst Band -- Brdcst Band - Band —- Band -- -- -- -- -- Lb ai/A 4 lb 3 lb —- 4 lb —- 4 lb 3 lb -- 4lb 3lb -— 3 lb 3 lb —- —- — -- -- - Yield Cwt/A Percent Tubersby Percent Tubers Size1 by Size1 A's B's Percent Tubers by Size1 Over 383 334 340 328 378 345 8 11 12 12 10 10 79 81 81 80 76 81 396 8 81 11 335 387 337 393 339 323 337 335 321 9 9 13 10 12 10 12 10 12 83 75 79 77 81 82 81 79 82 13 8 7 8 14 9 8 16 8 13 7 8 7 11 6 Spec. Grav. 1.067 —- 1.065 —- 1.064 —- 1.065 —- 1.067 -— 1.063 —- 1.066 —- 1.063 —- 1Grade sizes: B - to 1 7/8 in.; A - 1 7/8 to 3 1/4 in.; Oversize - over 3 1/4 in. Percent Good Percent Damag B's % of Tubers B's % Damag A's % of Tubers A' s % Damag Oversize Oversiz % of Tubers e % Damag 99.5 99.3 99.3 98.7 99.4 98.8 0.5 0.7 0.7 1.3 0.6 1.2 20.6 24.6 26.8 27.3 24.2 23.0 0.4 0.2 0.1 0.3 0.0 0.4 74.6 72.7 70.6 70.0 70.8 73.9 0.6 1.0 0.8 1.6 0.8 1.5 4.8 2.8 2.5 2.7 5.0 3.1 2551 99.1 0.9 20.5 0.4 75.4 1.0 4.2 0.9 2336 2685 2466 2712 2456 2261 2478 2303 2378 99.1 98.7 99.3 98.3 98.9 97.5 98.3 99.3 98.6 0.9 1.3 0.7 1.7 1.1 2.5 1.7 0.7 1.4 21.5 22.5 27.9 25.0 26.6 24.6 27.0 24.5 27.7 0.8 0.7 0.4 0.6 0.3 1.3 0.6 0.2 0.6 75.9 66.2 69.5 70.4 71.2 72.9 70.9 71.9 70.3 1.0 1.5 0.9 1.9 1.4 2.9 2.2 0.9 1.7 2.7 11.4 2.6 4.6 2.2 2.5 2.1 3.7 2.1 0.0 0.0 4.7 1.6 1.6 1.3 0.0 1.3 0.0 4.8 1.8 3.6 0.0 0.0 2.0 Results Although the primary objective of the study was to obtain control data for white grub infestations the populations were apparently too low to show differences between the feeding damage in the treated plots and that in the adjacent untreated plots. There were very few tubers showing wireworm damage therefore no damage ratings were made. The treatments which included band applications of Temik or Furadan resulted in a larger tuber size and approximately 50 cwt per acre increase in yield. There were no differences in the number or specific gravity of the tubers between the treatments. The data will be further analyzed by computer. BIOLOGY AND CONTROL STRATEGIES FOR INSECT PESTS OF POTATOES E. Grafius, M. A. Otto, E. Morrow, and H. C. Olsen Department of Entomology Insect pests of commercially grown potatoes in Michigan cause frequent concern to growers, but are generally kept well under control with the use of chemical insecticides, applied either as a preventive measure ("insurance sprays") or applied when the problem becomes apparent. Although these strategies are effective, the cost is high (approximately $50-75/A or $2-3 million per year in Michigan) and occasional unexpected pest outbreaks cause serious damage, either as the result of foliar damage or tuber damage. Our current research is focusing on two areas : 1) How to effectively detect and accurately assess insect populations and 2) What levels of pest populations can be present under various in potatoes (Sampling), cultural and environmental conditions before significant damage is caused (Economic Thresholds). The combination of these kinds of information with scouting programs (potentially available at a cost of approximately $10/A per year) will result in savings to the grower through: 1) Decreased need for preventive (insurance) treatments, and 2) Increased probability of detecting unexpected pest outbreaks (such as variegated cutworm in 1977, cabbage looper in 1978) in time to prevent serious damage. In addition, the reduction in insecticide usage would have considerable long term benefits in slowing the build-up of resistance to insecticides by pest species. Resistance to insecticides has already become a severe problem for control of Colorado potato beetle in the eastern U.S. and isolated cases of green peach aphid resistance to particular insecticides occur regularly in Michigan. The rate of resistance build-up must be slowed, at least to the point where it does not exceed the rate that new insecticides or groups of insecticides become available. One sure way of doing this is the reduction of insecticide use on a regional basis (what your neighbor does in this respect has an impact on you). Studies in 1980 continued to look at the impact of Colorado potato beetle on the potato plant under various conditions. Research was also continued on the detection, sampling, and impact of cutworms on potato production. Methods and Results Colorado potato beetle/root lesion nematode/fertilizer studies Field plots (4 rows x 50 ft) were established at the Montcalm Potato Research Farm. Each plot was treated to provide one of three levels of CPB infestation, one of two levels of nematode infestation, and one of three levels of fertil­ ization. There were a total of 18 different treatment combinations (Table 1). CPB populations were manipulated using insecticide applications timed to reduce populations, as needed. Numbers of adults, larvae, and egg masses were counted on four to six plants per plot in each of the three replications approximately weekly during the season. Mean number of CPB adults plus larvae per plant from June 17 to August 19 was 3.0 in the low CPB level plots (Fig. 1) and nearly all were very small larvae (1st or 2nd instars) that did virtually no damage to the plants. In the moderate CPB level plots, mean number of adults plus larvae per plant was 7.8 and there was a proportionately higher number of large larvae and adults. Mean number of adults plus larvae in the high CPB level plots was 10.6 larvae and/or adults per plant with a maximum value of 37.7 insects per plant on July 8, midway through the first generation of larvae. Nematode levels were established using a pre-plant soil fumigation or leaving natural soil populations intact. The predominant plant parasitic nematode was the root lesion nematode, Pratylenchus penetrans. Mean numbers of P. penetrans per 100 cm3 of soil at planting were 31.7 in the non-fumigated soil (range 8-104) and 6.2 in the fumigated plots (range 0-26). Numbers of P. penetrans per gram of root tissue on July 17 averaged 124.1 in the non-fumigated plots (range 30-328) and 38.6 in the fumigated plots (range 4-155). Fertilizer levels were established as indicated in Table 1. These levels of fertilization were chosen to determine how the effect of an additional stress (low soil nutrients) would affect the plant’s response to CPB and nematode damage. Plant samples were taken three times during the growing season to estimate leaf weight, root weight, and tuber development in the respective treatments. However, this data has not been analysed at this time. Plots were harvested on September 10 and 11 and data was collected on total yield from the center two rows of each plot (100 row ft), yield of size A tubers, yield and number of size B tubers, and yield and number of oversized tubers. A random sample of 60-100 tubers from each plot was taken to estimate number of A’s and mean weight per A tuber (Table 2). Analysis showed significant effects of CPB level, nematode level, and fertilization level on total yield, yield of A’s, yield of oversized, weight per A tuber, and number of A’s. Total weight of B’s was significantly affected only by fertilization level. Maximum total yield and maximum yield of size A tubers were equivalent to approximately 317 cwt/A and 291 cwt/A respectively and occurred in the low CPB/low nematode/medium fertilization treatment. A portion of the yield results given in Table 2 are shown in figures 2-7. Mean number of A tubers and mean weight per A are shown in each figure, since these two components make up yield of A’s (yield = number of tubers times weight per tuber). Since tuber number is thought to be determined relatively early in the plant's growth and tuber weight occurs later in the season (bulking), separating out the two yield components seems logical when we are trying to explain yield responses of the potato plant. As shown in figure 2a, total yield under normal fertilization conditions decreased with higher CPB or nematode populations, as expected. However, fumigation had little effect on yield when CPB levels were high. Number of A's decreased with CPB level but did not decrease significantly with increased nematode pressure, as expected (fig. 2b). Mean weight per tuber generally decreased with higher CPB and nematode populations but not at the highest CPB level. In this case, the number of tubers was apparently reduced to such an extent (fig. 2b) that tuber bulking was slightly higher on a per tuber basis. The average of plots at all fertilization levels showed a somewhat different picture. Yield was reduced by higher CPB and nematode levels, more or less as before (fig. 3a). However, mean number of tubers was much more drastically reduced (fig. 3b) and mean weight per tuber stayed relatively constant regard­ less of treatment. Here again, we see the interaction between tuber number and tuber weight. Under fertilization stress, the plant is apparently affected (especially by nematode damage) much earlier in its growth, resulting in the drastic reduction in tuber numbers. The effect of fertilization levels on the plants' responses to CPB levels are shown in figures 4 and 5. Total yield decreased with higher CPB populations at generally the same rate, regardless of the fertilization level (figs. 4a and 5a). The predominant effect of CPB level was expressed in fewer size A tubers (figs. 4b and 5b) rather than reduced weight per tuber (figs. 4c and 5c). It is interesting to note that the extra side-dressed urea ("normal" fertilization compared with "medium" fertilization) did not result in significant increases in yield or significant increases in either of the yield components at any level of CPB infestation ( figs. 4 and 5; compare - normal with = medium fertilization). Nitrogen at these levels is apparently not limiting to plant growth. The lack of response to the side-dressed N is also evident when we examine the effect of fumigation on the plants' responses to fertilization (figs 6 and 7). Total yield at all fertilization levels was increased by fumigation (figs. 6a and 7a). At low to medium levels of fertilization, number of tubers was strongly affected by nematode (fumigation) level (figs 6b and 7b), while at normal fertilization level, more of the yield increase occurred through inc­ reased weight per tuber, particularly at the low CPB level (fig. 6c). This may again have been the result of a low number of tubers set (see fig. 6b). Although the data presented here requires further analysis for positive conclusions to be reached, it suggests that impacts of stresses such as CPB defoliation or nematode damage are most often nearly additive in their effect on potato production. That is, a CPB population that would normally be expected to cause a 10% yield loss, for example, will cause a similar 10% loss even in the presence of other stresses such as nematodes or nutrient deficiences. If this proves to be the case, prediction of economic losses due to pest population observed in the field will be greatly simplified. Cutworm studies In 1980 variegated cutworm (VCW) populations were very low. They were not an economic problem in most potato fields. However, the spotted cutworm (SCW), a slightly smaller green worm, that is sometimes confused with the cabbage looper, was a problem in many Montcalm County fields. At the Montcalm Experimental Farm, we were not able to get natural infestations of either species. Our approach in the past has been to artificially infest plots from a laboratory reared colony, but unfortunately we lost our VCW colony to disease and thus were not able to artificially infest our plots set up to look at the influence of VCW’s on potato growth and yield. We are attempting to develop better tools to detect VCW population, since attacks are sporadic. Sex attractant and black light traps are being evaluated for use in a regional adult activity monitoring program. Adult activity information, when coupled with egg and larval development informa­ tion should allow us to better predict when larvae will be in potato fields. This will allow optimal use of sampling resources. After we have tested this trapping program at different population levels, it should allow us to assess the relative population pressure and hence the immediacy of the need to check field for larvae. Much more knowledge will be needed before individual trap catches can be used as threshold values for treatment decisions, however, a regional approach appears to have some merit. Work was conducted in several growers fields to assess cutworm population levels and their impact on potato production. Characteristics of the various cutworm populations are given in Table 3 and yield and damage results for the respective fields and treatments are shown in Table 4. In one field of Russet Burbank’s there was a fairly uniform population of 6.3 1.2 SCW per plant (mostly 4-5th instars) on 7/23 (Table 3). The SCW's made up 96% of the cutworm population with VCW and black cutworms (BCW) splitting the remainder. Tubers were all less than a half inch in diameter. The grower decided that he needed to control them at this point and used a single application of Monitor. In order to check what would have happened if he had let them go, we placed 6 clear plastic tarps that covered 5 rows by 20 feet at random in one corner of the field just prior to spraying. We tried to remove them before plant damage occurred, but were not successful. All the new growth on most of the plants was burned. This significantly reduced yield 26% from 287 cwt/acre down to 212 cwt/acre (Table 4). To sort out the SCW effect, we went back into the field and treated half of the area that had been under the plastic. SCW feeding did not significantly reduce the yield, although the yield was 11% lower in the area that remained untreated (179 ctw/acre vs. 212 cwt/acre). There was virtually no tuber feeding. In a second grower’s Onaway’s, we found 3.6± .8 SCW per plant (mostly 5th instars). The SCW population made up only 80% of the total cutworms found. VCW’s accounted for 16% and BCW’s 4%. The plants were further along (tuber 1/2-1 inch diameters) and the cutworms were larger so the grower decided to use a single application of Monitor. An odd comer was left untreated to check and see how much damage this population would do if it were let go. Yields in the untreated area were not significantly lower than the treated despite a 12% yield reduction (335 vs. 380 cwt/acre). However, the treatment significantly reduced tuber feeding over 85% from 1.2% of the tubers fed upon, to .15%. In another grower’s Onaway’s, an application of Sevin left a residual population of 6 ± 1 SCW per plant. SCW’s made up 96% of the total cutworm population. The Sevin apparently killed mostly younger instars since 98% of the SCW’s were 4-6th instars. The grower was concerned with the black cutworm popula­ tion level (20% of the plants sampled had at least 1 BCW/plant), so he used an additional application of Monitor. No control plot was left so it was not possible to compare treated and untreated areas. No significant yield differences or differences in tuber feeding were noted from groups of plants exhibiting cutworm feeding and those that apparently were not fed upon. Overall, 1.1% of the tubers sampled were fed upon. Occasional pests are difficult to work with in the field, because you never really know if there will be a population with which to work. We will con­ tinue in our endeavors to better understand the cutworm-potato plant inter­ actions. More stringent measures have been taken to protect our laboratory colony from disease to insure the possibility of artificially infesting plots to get better information on the effects of cutworms on potato production. Particular emphasis will be placed on developing a regional sampling program to alert growers of the need to check their fields, before it is too late and the damage already done. All this information will then be put in value terms to facilitate making better insect pest management decisions under a variety of conditions. Table 1 Treatment Combinations Colorado Potato Beetle Levels Nematode Levels Fertilizer Levels Low (insecticides applied as needed to prevent visible foliar damage). Non-fumigated (no pre-plant soil fumigation) Moderate (insecticide applied when damage began to be obvious) empty table cell High (insecticides applied only late in season to prevent population build-up and spread to other plots) Fumigated (pre-plant soil fumigation) Low (no fertilizer applied at planting) Medium (500 lb NPK 20-10-10 applied at planting) Normal (500 lb NPK 20-10-10 applied at planting plus 145 lb 45% urea as side dress at hilling time) 3 X 2 X 3 = 18 Treatment Combinations Figure 1. Mean numbers of Colorado potato beetle adults plus larvae per plant in low, moderate, and high treatment levels during June - August 1980. Table 2 Potato Harvest Data - Sept. 1980 Colorado Potato Beetle/Nematode/Fertilizer Studies Mean Yield (lb/100 ft) Mean Yield (lb/100 ft) Mean Yield (lb/100 ft) A’s 77.0 141.7 142.3 Mean Yield (lb/100 ft) Over’s 0.0 3.3 1.3 CPB Level Low Low Low Low Low Low Nematode Level Non-fumigated Non-fumigated Non-fumigated N Fertilizer Level None Added At Planting At Planting + Side Dressed Total 90.1 154.3 154.5 Fumigated Fumigated Fumigated None Added At Planting At Planting + Side Dressed 147.8 218.3 203.8 130.0 200.8 182.3 B’s 13.1 9.3 10.8 17.2 9.0 8.8 18.3 10.3 9.3 16.8 10.8 11.5 16.1 12.0 10.0 19.1 9.0 11.0 0.7 8.5 12.7 0.0 0.3 0.0 0.0 2.5 0.8 0.0 1.0 1.2 0.0 0.3 1.2 Mean Wt. per A (lb) 0.20 0.28 0.28 0.23 0.30 0.33 0.23 0.25 0.25 0.21 0.28 0.27 0.17 0.22 0.26 0.19 0.30 0.24 Mean Number A's/100 ft 381 500 508 557 681 547 229 494 465 425 500 436 142 322 344 317 318 372 Moderate Moderate Non-fumigated Non-fumigated Moderate Non-fumigated Moderate Moderate Fumigated Fumigated Moderate Fumigated High High High High High High Non-fumigated Non-fumigated Non-fumigated Fumigated Fumigated Fumigated None Added At Planting At Planting + Side Dressed None Added At Planting At Planting + Side Dressed None Added At Planting At Planting + Side Dressed None Added At Planting At Planting + Side Dressed 71.5 134.2 124.3 106.8 153.8 131.3 41.3 83.8 100.8 79.3 104.8 103.7 53.2 123.5 115.0 90.0 140.5 119.0 25.2 70.8 89.7 60.1 95.5 91.5 Figure 2. Yield responses to various Colorado potato beetle and nematode levels under normal fertilization. a) Total yield /1OO ft of row. b) Number of size A tubers per 100 row ft. c) Mean weight per size A tuber. Figure 3. Yield responses to various Colorado potato beetle and nematode levels averaged over all fertilization levels. a) Total yield/ 100 row ft. b) Number of size A tubers per 100 row ft. c) Weight per size A tuber. Figure 4. Yield responses to various levels of Colorado potato beetle and fertilization. a) Total yield 100 row ft. b) Number of size A tubers per 100 row ft. c) Mean weight per size A tuber. Figure 5. Yield responses to various levels of Colorado potato beetle and fertilization averaged over fumigated and non-fumigated plots. a) Total yield per 100 row ft. b) Number of size A tubers per 100 row ft. c) Weight per size A tuber. Figure 6. Yield responses to various levels of fertilization and nematodes at low Colorado potato beetle populations. a) Total yield per 100 row ft. b) Number of size A tubers per 100 row ft. c) Weight per size A tuber. Figure 7. Yield responses to various levels of fertilization and nematodes averaged over all Colorado potato beetle levels. a) Total yield per 100 row ft. b) Number of size A tubers per 100 row ft. c) Weight per size A tuber. Table 3. Densities and age distribution of selected cutworm species in selected Montcalm county fields. Potato variety Sampling date Cutworms Number Species1 Cutworms 7/23/80 Russet Burbank Russet Burbank 7/23/80 Russet Burbank 7/23/80 Onaway Field 17/17 Onaway Field 1 7/17 7/17 Onaway Field 1 Onaway Field 2 Onaway Field 2 Onaway Field 2 7/24 7/24 7/24 SCW BCW VCW scw VCW BCW scw BCW VCW 780 17 15 141 28 8 168 4 3 Cutworms % 96 2.1 1.9 79.7 15.8 4.5 96 2.3 1.7 1SCW - Spotted cutworm BCW - Black cutworm VCW - Variegated cutworm 2% in each instar with 6 being the final instar. Spotted cutworms Age distribution2 Spotted cutworms Age distribution2 Spotted cutworms Age distribution2 Spotted cutworms Age distribution 2 6 4 5 8.3 - - 40.5 - - 11.3 - - 42.3 - - 36.9 - - 42.9 - - 40.9 - - 28.4 - - 12.5 - - 3 99.9 - - 19.1 - - 2.4 - - Spotted cutworms Age distribution2 Spotted cutworms Age distribution2 2 .4 - - 4.3 - - — - - Avg. 4.5 - 4.8 4.3 5.1 - 5.2 - 6.0 Density avg. Spotted cutworms number±S.E./plant 6.32 ± 1.22 .14 ± .03 .12 ± .10 3.56 ± .80 .78 ± .39 .25 ± .25 5.67 ± .98 .23 ± .09 .1 ± .07 Table 4. Average yield and % tuber damage following selected insecticide treatments for cutworm populations.1 Potato variety Treatment Avg. yield2 cwt ± S.E./acre3,4 Avg.% tuber feeding4 Russet BurbankMonitor 4F .75 # A.I. Russet Burbank Lannate 2L 1 # A.I. under plastic Russet Burbank Untreated under plastic Onaway Field 1 Onaway Field 1 Monitor 4F .75 # A.I. Untreated Onaway Field 2 Monitor 4F .75 # A.I. 287 ± 20a 212 ± 25b 189 ± 13b 380 ± 36 335 ± 24 202 ± 18 0 0 0 .15 1.18* 1.11 1Cutworm species composition, age distribution and densities are described in Table 3. 2Weight of A + jumbo or oversize tubers. Samples varied in size from 5-9 row feet and replications varied from 4-10 per treatment. 3Treatment means in comparable groups followed by the same letter are not distinguishable from one another at the .05 level by the S-N-K multiple range test. 4An * denotes treatment mean values significantly different at .05 level by a t-test. FOLIAR INSECT CONTROL Arthur L. Wells Department of Entomology Twenty insecticide treatments including foliar and soil systemic materials or combination of both were evaluated against the foliar insect complex on potatoes in 1980. The plots consisted of paired 48 foot rows randomized in three replications using Russet Burbank variety of seed. The rows were left open during the planting operation on May 8 so the band appli­ cations of the systemics could be made prior to covering. A second applica­ tion of granules was sidedressed to the Disyston plot at the time of hilling. Recommended fertilizer, herbicide and fungicide programs were followed during the study. A CO2 sprayer delivering 50 gallons per acre was used to apply the foliar insecticides. Applications were started on July 1 and repeated on July 18, 24, August 7 and 14. The foliar insects were sampled with an insect net on July 1, 11, 18, 30, August 11 and 28 prior to the insecticide appli­ cation on the corresponding days. The data are presented in Tables 1-5. A vine killer was applied in early September and the plots were harvested on October 6. The potato yields, size distribution, and specific gravity from the plots are presented in Table 6. Results The foliar insect samples as presented in the Tables indicate an infesta­ tion of potato leafhoppers, tarnished plant bugs and Colorado potato beetles (CPB) were already in the plots at the time the first foliar treatments were applied. Since these samples had not been influenced by the treatments the counts from only the subsequent samples were included in the totals in the tables. The leafhopper and CPB counts in the BAS 263, Temik and Furadan plots were much lower than in the untreated plots at the first sampling indicating the effectiveness of these materials. The foliar treatments were applied again on July 18 and 24 at which time Pirimor 50W at 0.25 lb. ai/A was added to the Ambush treatment, Tiovel 3E at 0.75 lb. ai/A was applied to the Disyston plot and Monitor 4E at 0.75 lb. ai/A was applied to the first untreated plot. These were added to the respective plots to supplement the control against added insect pressure of green peach aphid and second generation CPB at this time. The effects of these treatments were noted in subsequent samples. The foliars were applied again on August 7 and 14 at which time the foliage was dying down in certain plots. The specificity of certain treatments against the chewing and sucking insects were most evident in Tables 2 and 3 (Colorado potato beetle and green peach aphid, respectively). Bay SIR 8514 plus Monitor, SN-72129, the synthetic pyrethroids (Pydrin, FMC 45806 and Ambush), Vydate and endosulfan (Tiovel) were effective in controling the potato beetles at the rates and intervals tested. The weakness of Bay SIR 8514 alone, SN-72129, Larvin, BAS 263 and Furadan against green peach aphids were apparent as shown in the Table 1. Control of Potato Leafhopper in Foliar Evaluation Study Treatment Total Insects/30 Sweeps July 18 Total Insects/30 Sweeps Total Insects/30 Sweeps July July 1 30 Total Insects/30 Sweeps July 11 Lb/A Total Insects/30 Sweeps Total Insects/30 Sweeps August August 11 28 Total Insects Am. Cy. 222,705 Am. Cy. 222,705 Bay SIR 8514 Bay SIR 8514 + Monitor Bay SIR 8514 + Monitor Monitor SN-72129 SN-72129 Pydrin FMC 45806 Ambush + Pirimor Larvin Larvin Vydate BAS 263 Temik Furadan Disyston Untreated Untreated 0.025 0.05 0.5 0.1 + 0.5 0.5 + 0.5 0.75 0.25 0.5 0.05 0.10 0.10 + 0.25 0.45 0.90 0.50 3.0 3.0 3.0 3.0 + 3.0 —- —- 3 2 14 4 10 12 1 7 19 7 3 2 16 4 4 5 17 20 5 4 3 6 17 5 2 3 22 9 0 0 0 6 8 5 2 1 0 1 1 7 7 13 15 7 24 17 27 50 18 7 7 1 3 20 4 1 5 2 20 28 5 1 9 1 4 1 30 52 4 3 0 0 1 4 1 7 2 4 2 16 0 0 4 0 1 2 7 13 0 0 2 0 0 2 0 1 1 2 0 0 0 2 3 5 4 3 7 4 4 3 1 0 2 3 2 4 0 7 2 4 15 18 47 17 37 28 88 139 31 17 16 6 8 38 9 14 8 16 25 55 Treatment Table 2. Control of Colorado Potato Beetle Adults and Larvae Total Insects/30 Sweeps July 11 Ad Total Insects/30 Sweeps Total Insects/30 Sweeps Total Insects/30 Sweeps Totals Total Insects/30 Sweeps Total Insects/30 Sweeps Totals Total Insects/30 Sweeps Total Insects/30 Sweeps Total Insects/30 Sweeps Total Insects/30 Sweeps Total Insects/30 Sweeps Ad August August July August August La July July July July July 1 28 28 11 11 1 11 18 30 30 La Ad Ad La Ad La La Ad Ad La Total Insects/30 Sweeps July 18 La Am. Cy. 222,705 0.025 Am. Cy. 222,705 0.05 Bay SIR 8514 0.5 Bay SIR + Monitor 0.1 + 0.5 Bay SIR + Mon. 0.5 + 0.5 Monitor 0.75 SN-72129 0.25 SN-72129 0.50 Pydrin 0.05 FMC 45806 0.10 Ambush + Pirimor Larvin 0.45 Larvin 0.90 Vydate 0.50 BAS 263 3.0 Temik 3.0 Furadan 3.0 Disyston 3.0 + 3.0 Untreated Untreated % of Total/Sample 18 4 3 4 4 3 5 3 2 2 4 11 3 3 2 3 5 5 5 6 2 360 327 246 310 429 424 330 300 300 362 328 324 344 397 0 0 10 153 382 280 98 5 2 1 1 0 2 1 1 0 0 1 0 0 0 0 1 1 0 0 1 1 79 42 51 20 10 75 4 1 27 5 63 121 75 36 7 4 21 263 485 498 99 7 8 35 20 14 2 3 3 12 4 16 37 19 16 1 0 0 15 39 27 30 40 16 10 4 0 21 3 0 15 5 59 91 45 28 6 23 1 6 49 235 70 125 81 63 50 7 60 14 4 37 10 33 116 59 28 21 14 6 66 101 134 92 23 5 0 0 1 4 1 0 7 0 14 5 13 2 0 40 0 2 1 0 8 44 79 34 17 2 16 11 1 12 10 17 42 17 4 13 1 8 12 4 7 40 54 51 7 1 0 8 2 3 48 5 21 89 73 1 33 2 21 83 5 31 60 28 78 9 8 1 2 5 5 17 18 24 24 24 10 8 6 1 4 12 3 84 10 13 0 0 0 1 0 0 8 2 4 2 10 2 3 0 0 1 0 0 16 209 248 142 96 24 82 34 14 78 42 91 219 119 58 43 22 16 97 156 172 19 206 127 68 25 11 109 10 4 105 17 161 308 216 69 49 69 43 355 540 764 81 Table 3. Control of Green Peach Aphid in Foliar Evaluation Study Treatment Total Insects/30 Sweeps July 18 Total Insects/30 Sweeps Total Insects/30 Sweeps July July 1 30 Total Insects/30 Sweeps July 11 Lb/A Total Insects/30 Sweeps Total Insects/30 Sweeps August August 11 28 Total Insects Am. Cy. 222,705 Am. Cy. 222,705 Bay SIR 8514 Bay SIR 8514 + Monitor Bay SIR 8514 + Monitor Monitor SN-72129 SN-72129 Pydrin FMC 45806 Ambush + Pirimor Larvin Larvin Vydate BAS 263 Temik Furadan Disyston Untreated Untreated 0.025 0.05 0.5 0.1 + 0.5 0.5 + 0.5 0.75 0.25 0.5 0.05 0.10 0.1 + 0.25 0.45 0.90 0.5 3.0 3.0 3.0 3.0 + 3.0 —- —- 2 0 0 0 0 0 0 0 0 0 0 2 1 0 0 0 1 0 0 0 0 1 20 1 5 3 26 34 1 2 4 0 16 29 26 1 13 0 2 5 9 1 55 22 9 8 108 90 8 16 30 101 163 37 100 2 52 5 53 56 3 0 40 1 7 0 129 90 3 1 2 54 21 25 148 5 85 0 1 49 0 0 23 0 0 2 11 0 3 0 0 0 8 5 2 8 6 4 5 54 0 0 2 0 0 1 2 1 5 5 11 1 1 0 4 6 4 2 4 3 12 2 146 29 23 21 280 218 20 73 36 157 201 94 283 19 165 8 61 113 Table 4. Control of Tarnished Plant Bugs in Foliar Evaluation Study Treatment Lb/A Total Insects/30 Sweeps Total Insects/30 Sweeps Total July July Insects 1 30 Total Insects/30 Sweeps July 11 Total Insects/30 Sweeps July 18 Total Insects/30 Sweeps August 11 Total Insects/30 Sweeps August 28 Am. Cy. 222,705 Am. Cy. 222,705 Bay Sir 8514 Bay SIR 8514 + Monitor Bay SIR 8514 + Monitor Monitor SN-72129 SN-72129 Pydrin FMC 45806 Ambus + Pirimor Larvin Larvin Vydate BAS 263 Temik Furadan Disyston Untreated Untreated 0.025 0.05 0.5 0.1 + 0.5 0.5 + 0.5 0.75 0.25 0.50 0.05 0.10 0.10 + 0.25 0.45 0.90 0.50 3.0 3.0 3.0 3.0 + 3.0 —- —- 25 23 22 14 26 26 30 5 26 32 33 17 18 27 18 5 15 26 13 10 31 24 27 28 32 23 35 42 37 12 41 15 19 33 22 13 16 27 20 23 26 33 32 22 29 33 31 19 32 23 34 20 17 29 18 10 26 21 21 26 12 6 23 5 6 10 18 16 14 2 3 1 8 4 16 3 13 4 5 10 16 6 17 4 6 13 11 27 18 2 3 2 0 7 28 5 16 10 2 9 7 7 0 5 3 6 19 7 8 1 10 2 1 6 9 3 1 4 11 5 92 76 99 64 76 85 114 111 109 40 91 40 45 79 93 34 72 66 59 73 Table 5. Predator and Parasite Populations in Foliar Evaluation Study (Lady bird beetles, wasps, spiders, etc.) Treatment Lb/A Total Insects/30 Sweeps Total Insects/30 Sweeps July July 1 30 Total Insects/30 Sweeps July 18 Total Insects/30 Sweeps July 11 Total Insects/30 Sweeps Total Insects/30 Sweeps August August 11 28 Total Insects Am. Cy. 222,705 Am. Cy. 222,705 Bay SIR 8514 Bay SIR 8514 + Monitor Bay SIR 8514 + Monitor Monitor SN-72129 SN-72129 Pydrin FMC 45806 Ambush + Pirimor Larvin Larvin Vydate BAS 263 Temik Furadan Disyston Untreated Untreated 0.025 0.05 0.50 0.10 + 0.50 0.50 + 0.50 0.75 0.25 0.50 0.05 0.10 0.10 + 0.25 0.45 0.90 0.50 3.0 3.0 3.0 3.0 + 3.0 —- —- 1 1 4 0 9 6 2 0 0 1 0 4 1 2 2 1 0 3 0 5 0 0 0 0 5 5 1 1 1 0 2 1 3 1 0 0 1 1 2 0 0 2 9 1 0 4 5 2 4 1 4 13 9 12 9 1 2 1 7 17 6 3 10 3 2 2 8 19 3 3 2 6 2 10 12 1 12 3 4 0 3 2 3 0 0 3 7 6 6 2 4 2 2 8 4 3 5 1 1 2 11 2 7 10 3 2 13 22 10 11 3 8 10 11 17 2 7 6 6 4 22 9 29 14 10 16 34 50 24 17 15 30 26 42 42 7 27 12 20 23 Table 6. Yield Data and Specific Gravity of Tubers from Foliar Evaluation Study Material and Formulation Percent by Grade Size Percent by Grade Size Off-Type A's Percent by Grade Size B's Percent by Grade Size Spec. 10 oz Grav. Rate (ai) per A Yield/A Foliar Applications Foliar Applications Foliar Applications Foliar Applications Foliar Applications Foliar Applications Foliar Applications Foliar Applications Am. Cy. 222-705 2.5 E Am. Cy. 222-705 2.5 E Bay SIR 8514 25 WP Bay SIR 8514 25 WP + Monitor 4 EC Bay SIR 8514 25 WP + Monitor 4 EC Monitor 4 EC SN-72129 50 WP SN-72129 50 WP Pydrin 2.4 EC FMC 45806 2.5 EC Ambush 2 E + Pirimor 50 W Larvin 500 Larvin 500 Vydate 2 L Soil Systemics BAS 263 10 G Temik 15 G Furadan 10 G Disyston 15 G Untreated Untreated 71 15 338 69% 68 74 18% 17 14 319 cwt 324 351 0.025 lb 0.05 0.5 0.1 0.5 0.5 0.5 0.75 0.25 0.5 0.05 0.10 0.1 0.25 0.45 0.90 0.5 Soil SystemicsSoil SystemicsSoil Systemics 337 358 375 319 300 384 15 14 15 19 19 14 69 68 73 72 66 70 297 273 341 301 19 17 18 18 68 69 71 68 5% 6 8 7 6 7 6 5 6 8 7 6 5 5 8% 9 4 7 10 11 6 4 9 8 1.072 1.076 1.075 1.072 1.073 1.074 1.071 1.071 1.076 1.074 6 7 6 9 1.071 1.074 1.076 1.073 Soil Systemics Soil Systemics Soil Systemics Soil Systemics 3.0 3.0 3.0 3.0 + 3.0 —- —- 341 434 411 301 265 189 17 10 14 17 22 34 70 67 69 69 67 62 4 10 8 4 6 1 9 13 9 10 5 3 1.072 1.076 1.073 1.077 1.072 1.069 sample counts. The insect damage in most of the plots had caused the foliage to die down by the time the vine killers were applied in early September. The tuber yields in the plots as shown in Table 6 indicate the influence of heavy beetle populations during the season. The highest yields came from the Temik and Furadan plots with 434 and 411 cwt/A, respectively. Most of the other treatments gave good yields except the untreated plot which was later treated with Monitor. It is apparent that with heavy beetle pressure it is important to protect the plants early in the season so they will not be under stress during early tuber formation. EFFECTS OF NEMATICIDES ON PRATYLENCHUS PENETRANS AND POTATO YIELDS G. W. Bird and H. C. Olsen Dept. of Entomology Temik 15G (3.0 lbs. a.i./A) and Mocap 10G (3.0, 6.0, and 12.0 lbs. a.i. /A) were evaluated throught the season for nematode control and yield response of Solanum tuberosum ’Superior'. A complete randomized block design was used with each treatment replicted five times. Seed pieces were planted on May 14, 1980 at the Montcalm Potato Research Farm in Entrican, Michigan. Each plot con­ sisted of four rows 50 feet long and 34 inches apart with seed piece spacing 8 to 12 inches. Temik 15G was banded with the fertilizer 2 inches to the side and down from the seed pieces at planting. Mocap 10G was broadcast immediately before planting. Soil samples were analyzed for nematodes using the centrifu­ gation-flotation technique and the roots were processed using the shaker ex­ traction technique. Insects were controlled by sprays of Sevin, Thiodan, and Monitor. Irrigation was applied when necessary. The center two rows of each plot were harvested, graded and weighed. There was a significant (P= 0.05) yield difference between treated plots and the check. Temik 15G had the greatest production of oversized tubers. There was a 66%, 71%, and 74% yield increase over the check with 3.0, 6.0, and 12.0 lbs. Mocap 10G respectively. Temik 15G provided an 84% yield increase. Nematode densities for all treatments were significantly (P=0.05) lower than the check throughout the season. There was no significant difference in nematode control between the nematicide treatments. Figure 1 Population of P. penetrans1 Treatment (a.i./A) Tuber Yields3 Oversized Tuber Yields3 Total4 Marketable Effects of Nematicides on Pratylenchus penetrans and Potato Yields Population of P. penetrans1 May 14 Population of P. penetrans1 Tuber Yields3 U.S. No. 1 Aug. 18 Population of P. penetrans1 July 1 Population of P. penetrans1 July 28 Temik 15G (3.0 lbs.) Mocap 10G (3.0 lbs.) Mocap 10G (6.0 lbs.) Mocap 10G (12.0 lbs.) Check 45.2a2 18.0a 18.2a 22.8a 28.6a 8.4a 0.8a 4.6a 3.0a 48.6b 1.8a 2.6a 1.6a 2.0a 172.4b 2.0a 0.4a 2.5a 0.8a 180.lb 214.2a 194.0a 200.4a 204.0a 117.4b 2.3a 0.9a 0.3a 0.3a 0.0a 216.5a 194.9a 200.7a 204.3a 117.4b 1P. penetrans/gram of root plus P. penetrans/lOOcc soil 2Column means followed by the same letter are not significantly different (P=0.05) according to the Student-Newman-Keuls Multiple Range Test 3CWT/A 4U.S. No. 1 plus oversized grade. EFFECT OF PRE-PLANT SOIL TREATMENTS ON THE CONTROL OF POTATO SCAB, 1979, 1980 Department of Botany and Plant Pathology H. S. Potter Nitrate inhibitors Dwell and Enserve were compared with the fungicide Terraclor and with combinations of Terraclor and Dwell for control of scab (Streptomyces scabies) on potatoes (var. Sebago). Tests were conducted on the Michigan State University Experimental Soils Farm, East Lansing, Michigan. Treatments were broadcast along with 150 lbs. of N as urea on the soil surface and pre-plant incorporated. The soil in the test plots was fine sandy loam with a pH of 7.2. It was known to be heavily infested with the scab pathogen S. scabies. Irrigation was used sparingly and only to maintain normal growth. Plots were mechanically weeded and sprayed weekly for disease and insect control. Temik was not used because of the possibility that it might interfere with the scab treatments. Certified Sebago seed was cut and planted on May 26, 1979 and May 30, 1980 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. The results of both tests indicate that the nitrate inhibitors Enserve and Dwell with urea will suppess scab symptoms as will Terraclor with urea. But by far the best control of scab and the highest marketable yield resulted from the combination of Dwell and Terraclor with urea. In the 1979 test it was apparent that Dwell used in this combination at the 1/2 lb rate was more effective than at the 1/4 lb rate. Harvested yield results in both tests suggest that Dwell and Enserve may be inhibiting potato growth. TEST 1 (1979) Treatment Rate/A Average Yield CWT/A1 Average Yield CWT/A1 Average Yield CWT/A1 Average Yield CWT/A1 Marketable Marketable Harvested Harvested B Grade U.S. #1 B Grade U.S. #1 Ave. % Marketable1,2 Tubers Dwell (Terrazole) Dwell Enserve Dwell + Terraclor 2E Dwell + Terraclor 2E Terraclor 2E No Treatment LSD .05 .25 lb ai .5 lb ai .5 lb ai .25 lb ai + 12.5 gal .5 lb ai + 12.5 gal 12.5 gal -- empty table cell 290.8ab 270.9 c 250.8 d 320.5 a 310.6ab 312.0ab 279.1 b 57.4 cd 90.7 c 99.1 c 54.2 d 66.5a 89.3 c 58.9 c 174.7 b 205.6a 63.0 b 150.1 b 57.2 cd 58.9 d 50.4 e 17.9 c 19.8 c 23.7 bc 32.1ab 41.7a 27.5 bc 11.5 d 31.2 c 36.6 c 35.6 c 54.5 b 66.2a 48.1 b 21.1 d 34.9 2.6 28.8 12.1 8.2 1Small letters indicate treatments that do not differ significantly at the 5% level according to the LSD test. 2Potato tubers with no more than 2% scab. NOTE: All treatments 150 lbs of N in the form of urea. TEST 2 (1980) Treatment2 Rate/A Average Yield CWT/A1 Harvested U.S. #1 Average Yield CWT/A1 Ave. % Marketable Average Yield CWT/A1 Average Yield CWT/A1 Tubers1,3 Marketable Marketable Harvested B Grade U.S. #1 B Grade Dwell (Pre-mix with urea) Dwell 2EC Enserve 2EC Terraclor or 2EC Dwell (Pre-mix with urea) + Terraclor 2EC Dwell 2EC + Terraclor 2EC Check .5 lb ai .5 lb ai .5 1b ai (1 qt) 12.5 gal .5 1b ai + 12.5 gal .5 lb ai (1 qt) 12.5 gal ---- LSD .05 empty table cell 178.3ab 172.8a 178.0a 186.7abc 201.0 cd 15.5a 18.0ab 20.8 b 20.7 b 16.2ab 150.4 b 152.0 b 147.1 b 162.1 b 183.4 c 13.2ab 15.7abc 17.2 bc 18.0 c 15.1abc 206.2 d 20.1ab 195.1 c 19.0 c 192.5 bcd 18.1ab 14.4 5.0 127.0a 17.4 12.1a 4.5 85.3 b 86.5 b 82.7 b 86.9 bc 93.1 cd 94.7 d 65.8a 6.4 1Small letters indicate treatments that do not differ significantly at the 5% level according to the LSD test. 2Nitrate inhibitors Dwell (Terrazol-Olin), Enserve (Dow). 3 Potato tubers with not more than 2% scab. NOTE: 150 lbs of N in the form of urea applied on all plots. EFFECT OF DELAYED PLANTING OF CUT POTATO SEED AND CHEMICAL SEED PIECE TREATMENT ON STAND AND YIELD - 1980 H. S. Potter Department of Botany and Plant Pathology Michigan State University Potato cut seed tests were conducted at the Montcalm Experimental Farm to evaluate the effect of delayed planting after cutting and chemical seed piece treatment on stand and yield. Certified Sebago seed was cut and treated 2 weeks before planting (April 27, 1980), 2 days before planting (May 9, 1980) and 0 days before planting (May 11, 1980). Chemicals were applied by dusting in a plastic bag or by dipping for 2 minutes and allowing seed to dry. Planting was done by hand 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 50 foot row. Temik was applied at planting for early insect control and supplemented with foliar applications of Thiodan as needed. Furgicide sprays were applied at regular intervals. Irrigation was used when necessary to main­ tain a vigorous growth. The stand count was taken 4 weeks after planting and plots were harvested on October 9, 1980. The best stand resulted from the Terraclor-captan dust treat­ ment applied at planting and the poorest stand from the sodium hypochlorite dip applied 2 weeks before planting. In most instances stand was significantly increased as the time between cutting and planting was reduced. Chemical treat­ ments generally had a beneficial effect on stand and tended to offset somewhat the detrimental effect of delayed planting. Yield increases in some but not all cases appeared to be correlated with increased stand. Some chemical treatment significantly increased yields of US #1 potatoes others did not. The more effective treatments were the captan dust, the captan + streptomycin dust, and the stretomycin dip. The least effective treatments were the sodium hypo­ chlorite dip and chlorine dioxide dip and the Dithane M-45 oust. The water treatment was particularly detrimental. It significantly reduced both the stands and the yields as compared with the check. 1980 RESULTS: POTATO SEED TREATMENT TRIALS TREATMENT AND RATE___________________ SODIUM HYPOCHLORITE (CLOROX) 500 PPM DIP " " Chlorine Dioxide (Penetraat CLO2) 100 ppm " " " " " " " METHOD OF APPLICATION 14 X X 9.5 63.5 62.87 8.6 10.8 81.3 88.5 11.4 8.3 15.4 56.9 77.6 91.0 316.1 336.1 327.5 195.3 255.9 396.9 285.1 TIME APPLIED BEFORE PLANTING- DAYS 0. % STAND US #1 B GRADE 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 empty table cell table cell empty empty table cell table cell 380.4 389.6 347.5 10.5 10.2 80.1 84.2 83.9 7.1 8.3 X 379.2 385.9 355.8 378.2 397.3 308.4 327.5 346.0 361.3 304.4 360.4 8.3 12.3 5.2 7.1 10.2 9.2 8.6 14.8 12.3 13.8 11.7 89.7 92.6 83.0 85.5 91.0 78.8 87.2 90.4 90.3 87.2 92.0 TIME APPLIED BEFORE PLANTING- DAYS X empty table cell empty X table cell empty table cell empty X table cell empty table cell empty X table cell TIME APPLIED BEFORE PLANTING- DAYS 2 empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell X X X X X X 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 empty table cell X X empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell X X X X X X X X 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 empty empty table cell table cell empty empty table cell table cell X empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell X X X X 96.1 354.3 266.0 60.3 241.4 64.0 72.8 315.8 72.4 303.8 344.4 67.5 352.7 83.3 13.8 9.8 6.8 7.1 9.0 9.2 11.7 3.4 4.6 14.9 19.8 1.7 2.3 " " " " " " " " " " " " " " " " Dust Streptomycin Sulfate (Agri-Strep) 100 ppm " Streptomycin Sulfate+ Captan 10D + 10D 1 lb/cwt of seed CAPTAN 10D " " " " " " 1 LB " " " " THANE M-45 10D " " " " 1 LB CAPTAN + TBZ 10D + :5D .75 LB KL491 25W 15.25 grs/2 gals of water 1 LB/CWT OF SEED TERRACLOR 10D TERRACLOR + CAPTAN 10D + 10D 1 lb/cwt OF SEED --- WATER " --- " --- NO TREATMENT --- " " --- --- LSD .05 LSD .01 " " " " " " " " " DIP DUST " empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell 1980 TRIALS WITH SYSTEMIC SURFACE PROTECTANT FUNGICIDES FOR CONTROL OF EARLY AND LATE BLIGHT OF POTATOES Investigator: H. Spencer Potter, Department of Botany and Plant Pathology, Michigan State University, East Lansing, MI 48824 Location: Variety: MSU Muck Crops Research Farm, Bath, MI Russet Burbank (Certified Seed) Soil Type: Muck (Reed-Sedge Type) irrigated Row Spacing: 34 inches, Plant Spacing: 12 inches Planting Date: June 2, 1980 Harvest Date: October 12, 1980 Experimental Design: Randomized block with 3 replications. Plots were 2 rows wide and 50 feet long separated by 2 unsprayed guard rows. Method of Application: Granular soil treatments applied with funnel applicator. Foliar application with a CO2 backpack sprayer using a single row boom with 3 hollow cone nozzles (one overhead and 2 on drops). The operating pressure was 40 psi and the volume sprayed 25 gals/A. Spray Schedule: Pesticides Applied: A. In furrow treatments - June 2, 1980 B. Hilling treatments - July 12, 1980 C. Foliar treatments - July 18 thru September 23, 1980 At 7 to 14 day intervals. Some treatments required only a single application at flowering (August 3-10) other treatments applied only after late blight appeared (August 19). Herbicides: Lorox 50 W 1.5 Ib/A Insecticides: Thiodan 3EC 1 qt/A, August 19 and Sept. 2. Fungicides: see table Summary: The systemic compounds Ridomil, RE 26745, RE 26940 and RE 31155 applied to the foliage gave control of late blight that was equal to or better than that obtained with Dithane M-45 at the recommended rate. None of these systemics alone controlled early blight. Ridomil with CGA 64250 and RE 26745 with JX-13 were very effective against both early and late blight. A single application of Difolatan at the 4 qt rate either alone or in combination with RE 26745, RE 26940 and RE 31155 was less effective for control of early blight than Dithane M-45, and JX-13. The yield increase for all treatments was highly significant as compared to the check. There were significant differences in yield between some treatments but these did not in all cases reflect significant differences in disease control. Results: Treatment and Rate/A Application Schedule No. Of Applications Disease Index1 Disease Index1 Late Blight Early Blight 3.2 2.3 3.4 2.2 2.4 2.3 4.9 2.4 2.6 2.3 5.8 1.8 2.2 2.1 2.5 3.0 3.2 1.3 1.7 7.1 3.8 3.2 3.7 2.0 2.8 2.6 5.0 6.1 5.9 6.2 3.7 4.5 4.3 4.8 3.8 6.2 5.9 6.0 1.8 6.1 .3 .4 1 1 1 1 1 1 1 1 2 2 Yield CWT/A Yield CWT/A B Grade US # 1 % Tuber Rot 268.2 282.1 262.4 306.6 272.2 283.3 249.4 294.0 271.1 298.3 220.1 327.2 324.6 322.3 315.5 280.5 267.2 295.2 102.4 84.3 92.0 84.1 119.6 91.0 86.2 91.7 89.9 68.4 76.6 91.7 102.0 105.3 101.4 98.2 111.8 72.5 4.9 3.2 4.8 . 3.4 5.6 4.2 2.8 1.8 2.2 1.9 8.6 1.8 2.4 2.2 1.6 2.7 1.9 0.6 336.1 82.1 0.4 203.0 29.9 40.1 102.4 17.1 22.8 1.2 1.5 7.7 Dithane M-45 80W 1 lb Dithane M-45 80W 2 lb Di thane M-45 3.8F .8 qt Dithane M-45 3.8F 1.7 qt Dithane M-45 80W 2 lb Dithane M-45 3.8F 1.7 qt Difolatan 4F RE 26940 50W RE 26745 50W RE 31155 50W JX-13 50W RE26940 50W + Difolatan 4F RE 26745 50W + Difolatan 4F RE 31155 50W + Difolatan 4F RE 26745 50W + 4 qt 2 lb 2 lb 2 lb 2 lb 2 lb 4 qt 2 lb 4 qt 2 lb 4 qt 2 lb 2 lb 15 lb 15 lb 1.5 pt JX-13 50W Ridomil 15G Ridomil 15G Ridomil 2E 1 pt 11 11 11 11 6 6 Spray 7 day Spray 7 day Spray 7 day Spray 7 day Spray 14 day Spray 14 day Spray at flowering Spray at flowering Spray at flowering Spray at flowering 1 Spray at flowering Spray at flowering Spray at flowering Spray at flowering Spray at flowering 1 1 2 In furrow at planting At hilling Spray 7 daywwhen B1. appears + Spray 14 days thereafter Spray 7 day when late B1. appears + Spray 2 14 days thereafter Ridomil 2E + CGA 64250 3.6E .75 pt 9 oz Check LSD .05 LSD .01 -- empty table cell empty table cell.3 empty table cell empty table cell.4 -- 1Disease Index = 0=no disease - 10=100% defoliation 1980 FUNGIGATION TRIALS FOR CONTROL OF LATE BLIGHT ON POTATOES Investigator: H. Spencer Potter, Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan 48824 Location: Variety: Pathogen: Michigan State University Muck Research Farm, Bath, Michigan Russet Burbank Phytophthora infestans Soil Type: Muck (reed-sedge) - irrigated Planting Date: June 2, 1980 Harvest Date: October 4, 1980 Experimental Design: Treatment randomized in 2 parallel blocks with 4 replications. Plots were semi-circular with a radium of 26 ft (.025 acres) and separated by an unsprayed area of the same size. Method of Application: Solid set irrigation with sprinkler heads on 3' risers spaced 50 ft apart and adjusted to operate in a 180° arc. Pressure at the sprinkler heads was 70 psi. Spray suspensions (20X concen­ trations) were injected into the irrigation systems at 120 psi using a fertilizer proportioner and a power sprayer. A colored dye was mixed with the spray suspensions to indicate the beginning and end of treatments. Plots were treated with a single sprinkler at a volume of 600 gals/A. Treatments were started on July 25, 1980 and continued on a 7 day schedule (Ridomil + CGA 64250 on a 14 day schedule) thru September 24, 1980 (Ridomil + CGA 64250 5 applications, other treatments 10 applications). Pesticides Applied: Herbicides: Lorox 50W 1.5 Ib/A 1 application by ground sprayer Insecticides: Thiodan 3EC 1 qt/A 2 applications thru the irrigation system. Fungicides: See table below. Results: Treatment and Rate/A Late Blight Foliar Disease Index1 cwt/A2 Yield Yield cwt/A 2 US #1 B GRADE % Tuber Infection Ridomil 2E 16 oz + CGA 64250 3.6E 9 oz Bravo 500 2 pts Quintar 5 F 6.4 oz + Plyac 4 oz Manex 4 F 1.6 qts Check LSD .05 LSD .01 .4 1.1 1.8 1.7 4.5 271.3 253.4 242.6 255.5 194.1 55.8 63.9 70.4 68.3 56.0 .9 1.9 2.8 2.9 8.5 0.2 0.3 17.2 23.8 N.S N.S 2.8 3.8 1Disease Index O=no disease - 10=100% defoliation 2Average yield based on weight of tubers from 2 20 ft of row samplings. Summary: All treatments were effective in controlling late blight. Ridomil + CGA 64250 was the most effective treatment and resulted in the highest yield of US #1 potatoes. 1980 FOLIAR SPRAY TRIALS FOR DISEASE CONTROL ON POTATOES Investigator: H. Spencer Potter, Department of Botany and Plant Pathology, Michigan State University, East Lansing, MI 48824. Location: MSU Botany Farm, East Lansing, MI 48824 Crop Variety: Sebago Soil Type: Sandy Loam - irrigated Row Width: 34 inches, Plant Spacing: 12 inches Planting Date: May 27, 1980 Harvest Date: October 6, 1980 Experimental Design: Randomized block and 4 replications with single row plots 50 feet long separated by unsprayed guard rows. Spray Schedule: Weekly, starting July 6 and Ending September 21 (11 applications) Method of Application: Co2 backpack-sprayer with a single row boom and 3 flat fan S.S. 8003 low pressure nozzles (1 overhead and 2 on drops). Operating pressure was 20 psi and volume of spray applied 25 gals/A. Pesticide used: Eptan 7E, 3.5 pts/A preplant incorporated, Sencore 50 WP .5 Ib/A Herbicides: 2 post emergence applications. Insecticides: Thiodan 3EC 1 qt/A 3 applications with Fungicides Fungicides: See table below. Results: Treatment Quintar 5F 9 oz/A Quintar 5F 12.8 oz/A Quintar 5F 25 oz/A Qunitar 5F 12.8 oz/A + Dithane M-22 80 W .5 Ib/A Dithane- M-22 80 W 1.5 Ib/A BFN 8099 40EC 4.1 oz/A BFN 8099 40EC 12.6 oz/A Bravo 500 2.25 pts/A Check LSD .05 LSD .01 Disease Index1 Early Blight Yield cwt/A US #1 Yield cwt/A B Grade 3.2 2.9 2.5 2.0 1.8 1.3 1.1 1.4 6.0 171.7 184.5 188.9 204.5 205.7 216.9 215.4 224.1 164.2 22.9 24.0 28.7 22.3 21.5 16.5 15.2 15.0 36.9 .2 .3 16.1 22.0 6.8 9.3 1Disease Index = 0 =no disease - 10=100% defoliation Summary: All fungicide treatments had significantly less early blight than the check. The experimental compound BFN 8099 and Bravo 600 resulted in significantly better disease control than any of the other treatments. Quintar’s effectiveness increased as the rate of application increased. However, it was more effective at the 12.8 oz rate in combination with the .5 lb rate of Dithane M-22 than it was alone at 25 oz per acre. Treatments providing the best disease control also had the highest yields. INFLUENCE OF SELECTED PRODUCTION MANAGEMENT INPUTS ON WEIGHT LOSS AND MARKET QUALITY OF STORED POTATOES DUE TO STORAGE ENVIRONMENTS Dept. of Agricultural Engineering, Michigan State University B.F. Cargill * INTRODUCTION (The 1979 MSU Integrated Project) The MSU Integrated Project is a multi-disciplinary phase involving all aspects of potato production and handling from planting the potatoes in 1979 through a 1980 study of seed viability after storage of the 1979 crop. Superior potatoes for this Integrated Phase were planted May 9, 1979 in Range 5 at the MSU Montcalm Potato Research Farm under the supervision of Dr. Richard Chase of the MSU Department of Crop and Soil Sciences. These Super­ ior potatoes were produced using three (3) levels of phosphorus, two (2) nema­ ticides and a check. There were nine (9) treatments replicated five (5) times in Range 5. The production management objective of this study was to examine the vary­ ing phosphorus levels and their interaction with selected control programs. Researchers in the Departments of Crop and Soil Sciences; Entomology; and Botany and Plant Pathology were responsible for the production phase. Superior potatoes were planted in four (4) row plots (rows each 50 feet or 15.24m long and 34 inches or 0.86m apart). Seed pieces were spaced 8 to 12 inches (20.5 - 30.5cm) in the row. A four (4) row plot was used for a treatment. Superior seed pieces were of phosphorus (50, 150 lb/acre) and two nematicides (Temik 15G 3.0 a.i./acre, Vorlex 10 gal/acre). Temik 15G was applied in the seed piece furrow at plant­ ing and Vorlex was injected to a 6-8 in. (15-20cm) soil depth on May 1, 1979. Those plots to receive phosphorus were applied with either 50 lbs/acre or 150 lbs/acre P2O5 at planting. All plots also received a uniform application of 500 lbs/acre NPK (20-0-0) at planting. The plots were hilled and sidedressed at an application rate of 145 lbs/acre Urea (45%) on June 20, 1979. At harvest, only the two center rows of each plot were harvested, graded, and weighed. During the season, plots were maintained under normal commercial irrigation and insect and disease control practices. PROCEDURE (The storability phase of the MSU Integrated Project) a. Seed viability: representative samples of potatoes were obtained during the 1979 harvest from the nine treatments and five appli­ cations--45 sample bags containing approximately 25 pounds each after harvesting. *Other Researchers on this storage project: Dr. H.S. Potter, Dept. of Botany and Plant Pathology, Dr. J.N. Cash, Dept. of Food Science and Human Nutrition, Dr. Richard Chase, Dept. of Crop and Soil Sciences August 24, 1979 these sample bags of potatoes were weighed and placed in the MSU storage cubicles for 3 weeks at 60°F and 95% RH for suberization. After suberization the storage temperature was lowered 5°F per week until the desired storage temperature of 40°F was obtained. These potatoes were planted by Dr. Chase on May 9, 1980 to determine seed viability. The seed potatoes from the 1979 production were evaluated in 1980 for plant stand count, total yield in cwt/A; % grade #1, and specific gravity. b. Tuber quality: sample bags (approximately 25 pounds each) were obtained and stored for tuber quality evaluation; 45 bags (9 treatments and 5 replications) were stored at 40°F after suberization and another 45 bags were stored at 50°F. These potatoes were weighed and evaluated for marketable quality at four storage intervals from December 24, 1979 to April 15, 1980. c. Weight loss: two lots of 45 sample bags, each approximately 25 pounds per bag, were stored at 40° and 50oF after suberization. These potatoes were weighed six different times after harvest (67 to 281 days storage). DISCUSSION AND RESULTS The influence of selected management inputs on Superior yield, grade, and specific gravity are shown in Table 1. The weight loss information is shown in Tables 2-5. Various samples of Superior potatoes from the MSU Potato Farm were stored in the MSU cubicles. The weight loss data in Table 2 is from potato samples for tuber quality evalua­ tion, however, all samples stored were weighed. Table 2 shows that there is a steady increase in weight loss over the storage period. The reason that there is a decreasing number of sample bags over the duration of the storage is that some sample bags are removed for tuber evaluation (after tuber evaluation, these potatoes are removed from the test). One purpose of continually researching weight loss is to establish a "weight loss factor" (weight loss per day in storage) for various storage conditions. The weight loss factors for the Superior potatoes in Table 2 are: Storage period, days Weight loss factor Weight loss factor wt loss/day, % wt loss/day, % 50oF 40oF 118 167 195 233 281 .044 .042 .050 .059 .071 .039 .036 .040 .041 .047 There is no apparent effect of the nine production treatments as shown in Table 2 on weight loss. Weight loss data for a sample of Superior potatoes designated for a weight loss study are shown in Table 3. This table shows there is a steady increase in weight loss over the storage period for Superior potatoes stored at 40F and 95% RH. The weight loss factor is: Storage period, days 118 174 195 237 256 Weight loss factor wt loss/day, % 40°F .038 .034 .033 .032 .034 Table 1 Production Treatments Influence of selected management inputs on the yield, grade and specific gravity of 1979 Superior potatoes grown at the Montcalm Potato Research Farm Farm, Entrican, Michigan Yield (CTW/ACRE) A Grade Yield (CTW/ACRE) Total Specific Gravity Yield (CTW/ACRE) B Grade Yield (CTW/ACRE) Jumbo Grade 1 OP2 Check 2 OP Temik 15G 3 lb a.i./acre 3 OP Vorlex 10 gal/acre 4 50P Check 5 50P Temik 15G 3 lb a.i./acre 6 50P Vorlex 10 gal/acre 7 150P Check 8 150P Temik 15G 3 lb a.i./acre 9 150P Vorlex 10 gal/acre 215.0a1 247.5ab 277.5bc 247.7ab 276.8bc 298.1c 282.7bc 315.7c 324.6c 10.9a 13.2a 14.9a 10.5a 11.2a 12.7a 11.6a 11.9a 12.3a 10.5a 20.0ab 22.6abc 15.0ab 28.7bcd 38.1d 19.4ab 36.4cd 29.9bcd 236.7a 280.7ab 314.9bc 273.3ab 316.7bc 348.9c 313.7bc 364.1c 366.7c l.066ab l.066ab 1.067ab 1.066ab 1.065a 1.068b 1.068b 1.066ab 1.068b 1Column followed by the same letter are not significantly different (P = 0.05) according to the Student-Newmans-Keuls Multiple Range Test. 20 P = 0 lb. phosphorous per acre Superior potatoes seed pieces were planted May 16-17, 1979 and harvested August 24, 1979. Table 2 Influence of storage duration on weight loss from 1979 Superior potatoes using nine different production treatments and stored at 40° and 50°F and 95% relative humidity. 50°F Production Treatments* and Storage Temperature 1 2 50°F 3 50°F 50°F 4 5 50°F 6 50°F 50°F 7 8 50°F 9 50°F 50°F Av. 1 2 40°F 3 40°F 4 40°F 40°F 5 40°F 6 7 40°F 8 40°F 9 40°F 40°F Av. 40°F 671Weight Loss, % Storage Period, Days Storage Period, Days 1181Weight Loss, % Storage Period, Days 1672 Loss, % Weight Loss, % Storage Period, Days319 5 Weight Storage Period, Days2334Weight Loss, Storage Period, Days2815Weight Loss, % % 4.9 5.1 5.2 5.1 6.0 5.5 4.8 5.2 5.2 5.2 3.7 3.9 4.2 4.3 4.1 4.1 3.9 4.1 4.1 4.0 ** 4.2 empty table cell4.7 empty table cell4.7 empty table cell4.2 empty table cell4.3 empty table cell4.7 empty table cell3.9 empty table cell5.0 empty table cell4.4 empty table cell4.6 6.3 7.1 7.7 6.9 7.2 7.6 6.8 7.5 7.1 7.1 5.8 6.2 6.1 5.7 6.1 6.9 5.8 6.2 6.4 6.1 8.9 9.0 10.0 9.3 9.8 10.9 9.8 9.7 9.8 9.7 7.6 7.4 7.9 7.5 7.8 8.4 7.0 7.7 8.0 7.7 13.5 14.1 14.2 12.5 14.0 15.0 12.8 13.5 13.4 13.7 9.2 9.2 9.5 9.4 9.5 10.6 9.2 8.6 10.3 9.5 18.8 20.7 22.2 20.0 19.7 —— 17.9 19.0 21.2 19.9 13.8 13.7 12.6 12.2 13.0 14.6 13.2 12.1 14.6 13.3 1Average weight loss from 5 Sample bags—sample bags approximately 25 lbs each 2 Average weight loss from 4 sample bags 3Average weight loss from 3 sample bags 4Average weight loss from 2 sample bags 5Average weight loss from 1 sample bag * No. 1. 2. 3. 4. 5. 6. 7. 8. 9. Phosphorus Rate 0 lb P205/A 0 lb P205/A 0 lb P205/A 50 lb P205/A 50 lb P205/A 50 lb P205/A 150 lb P205/A 150 lb P205/A 150 lb P205/A Pesticide Check Temik Vorlex Check Temik Vorlex Check Temik Vorlex **No data taken for this storage period Table 3 Influence of storage duration on weight loss from 1979 Superior potatoes different production treatments and stored at 40° and 95% relative humidity. Production Storage Period, Days Storage Period, Days Treatments ** 237 256 Weight Loss, % *** Weight Loss, % *** Storage Period, Days Storage Period, Days 174 195 Weight Loss, % *** Weight Loss, % *** using nine Storage Period, Days 34 Weight Loss, % *** Storage Period, Days 118 Weight Loss, % *** * 1 2 3 4. 5. 6. 7. 8. 9. Av. 3.6 3.5 4.1 4.0 3.3 3.2 3.7 4.1 4.5 3.8 4.0 4.2 4.9 5.1 3.8 4.2 4.4 4.7 5.2 4.5 5.6 5.4 6.5 6.1 5.3 5.3 5.7 6.4 6.5 5.9 6.3 5.9 7.1 6.8 5.7 5.9 6.3 6.9 7.2 6.5 7.5 7.2 8.2 7.7 6.7 7.0 7.3 8.0 8.3 7.5 8.9 8.2 9.6 8.7 7.9 8.2 8.5 9.1 9.4 8.7 *Sample bags of Superior potatoes from the MSU Integrated Potato plots were specifi­ cally stored for weight loss determination **Refer to Table 2 footnotes for description of production treatments ***A11 data is the average of five sample bags—-each sample bag is approximately 25 lbs Again Table 3 shows that there is no apparent effect of the nine production treatments on weight loss. One lot of Superior potatoes was specifically stored (40°F and 95% RH) for seed viability. These samples were placed in the cubicles on August 24, 1979 and not moved or weighed until they were removed for planting for the seed viability study on May 8, 1980 (256 days in storage.) Table 4 illustrates a justified researcher concern in the weight loss studies; periodically moving sample bags of potatoes for weighing may influence the weight loss data. The weight loss factor for this 40°F lot is .021 for 256 days at 40°F; compared to .034 (Table 3) and .059 (Table 2). Table 4 Weight loss from 1979 Superior potatoes stored (for seed viability at 40°F and 95% relative humidity. *) in MSU cubicles Production ** Treatment Initial Weight Aug. 24 ’79 Final Weight May 8 '80 Weight Loss Weight Loss % lbs. 1 2 3 4 5 6 7 8 9 Av. 28.1 30.1 30.2 28.9 31.8 32.1 30.2 3.26 31.0 26.8 28.7 28.4 27.8 30.4 30.2 28.4 30.5 29.3 1.3 1.4 1.8 1.1 1.4 1.9 1.8 2.1 1.7 empty table cell 4.6 4.7 6.0 3.8 4.4 5.9 6.0 6.4 5.5 5.3 empty table cell empty table cell *Superior potatoes from the MSU Integrated Potato Project were stored at 40°F and 95% RH. These potatoes were planted May 9, 1980 to determine seed performance. See Superior seed performance Table 8 for results. **Refer to Table 2 footnotes for description of production treatments Table 5 is a comparison of two nematicides on weight loss. In the 1979 report comparing Temik and Vorlex there appeared to be a higher weight loss in Superior plots with Vorlex than Temik. It again appears in Table 5 that Vorlex may be associated with a higher weight loss. In 12 of the comparisons shown in Table 5, ten of twelve lots show Vorlex associated with a greater weight loss than Temik. On the other hand, there appears to be no association between levels of P2O5 and weight loss; the average weight loss of the four storage lots in Table 5 are: 9.3%, 9.8% and 9.4% for the 0, 50, and 150 lbs P2O5 respectfully. In summary for Superior potatoes, the 1979 data indicates the follow­ ing weight loss factors: empty table cell 40° 50° Weight Loss Factor, % Weight Loss Factor, % Weight Loss Factor, % 8 mos. 6 mos. 4 mos. 11.0 6.5 4.6 14.6 8.3 5.3 Table 5 Comparison of extended storage weight loss from Superior potatoes grown in Temik and Vorlex plots at three levels of phosphorus. Production Treatments Storage Lot Numbers* 1 Storage Lot Numbers* 2 Storage Lot Numbers* 3 Storage Lot Numbers* 4 Av. 0 P 205 50 P 205 150 P205 Temik 0 P 205 Vorlex 205 Check 0 P Temik 50 P 205 50 P 205 Temik 150 150 Vorlex Check P205 Vorlex P205 Check 9.2 9.5 9.2 9.5 10.6 9.4 8.6 10.3 9.2 13.7 12.6 13.8 13.0 14.6 12.2 12.1 14.6 13.2 4.7 6.0 4.6 4.4 5.9 3.8 6.4 5.5 6.0 8.2 9.6 8.9 7.9 8.2 8.7 9.1 9.4 8.5 9.0 9.4 empty 8.7 9.8 table cell empty 9.0 10.0 table cell table cell empty *Storage Lot Numbers 1 2 3 4 Superior Tuber Quality Lots, Stored 233 days at 40°F and 95% RH Superior Tuber Quality Lots, Stored 281 days at 40°F and 95% RH Superior Seed Viability Lot stored 256 days at 40°F and 95% RH Superior weight loss lot stored 256 days at 40°F and 95% RH Superior potatoes grown on the MSU Research Farm for the MSU Inte­ grated Project were stored at 40° and 50°F and 95% RH and evaluated for marketable quality after various periods of storage, Tables 6 and 7. Table 6 contains the quality data from the Superior lots specifically stored for market quality evaluation. Five sample bags from each treatment were stored at the specified environment. One sample bag (approximately 25 lbs) was evaluated from each treatment at various periods during storage. Dr. H.S. Potter (Botany & Plant Pathology) evaluated each individual tuber for quality after the various periods of storage. Market quality is a subjective determination. Each sample lot was divided into ten categories: 1. Marketable 2. 0 to 5.0% dry rot 3. 5.1 to 10.0% dry rot 4. 10.1 to 25.0% dry rot 5. Over 25.0% dry rot 6. 0 to 5.0 soft rot 7. 5.1 to 10.0 soft rot 8. 10.1 to 25.0 soft rot 9. Over 25% soft rot 10. Other reasons (but not due to storage such as insect, excess scab, etc.). This above evaluation destroyed a sample lot, therefore, only one lot was evaluated on a specific date except one date. On April 15, 1980 two sample bags were evaluated from each treatment to observe the potential variability between sample bags stored at random in the same MSU cubicle. Lot IV averaged 95.8% good where as Lot V averaged 98.6% good. Therefore, it may be concluded that a ± 1.4% variation may be applied to the data for the 40° and ± 2.5% to the data for 50°F. In Table 6, there appears to be no apparent difference in market quality at a specific storage attributable to the production treat­ ments. Two lots of Superior potatoes were stored for other than market quality evaluation purposes: Lot SWL for weight loss and Lot SS for seed viability. However, at the conclusion of the storage season and just prior to the 1980 planting, these lots were evaluated for market quality, Table 7. A comparison of the data for comparable potatoes in Tables 6 and 7 shows the average marketable quality at 97.2% (Table 6) and 95.7 (SWL) and 95.6 (SS) Table 7 for potatoes stored 8 months at 40°F. This average of 96.2% for the three lots is higher than one might expect. These Superior potatoes were: special pro­ duction management at the MSU Potato Research Farm; harvested with the MSU Plot harvester under ideal weather and temperature conditions; immediately stored at 60°F for suberization, and stored at 40°F and 95%. Again as in Table 6, the data in Table 7 shows no apparent difference in marketable quality attributable to the nine production treatments. Table 6 Marketable Superior potatoes grown on the MSU Potato Research Farm under nine produc­ tion treatments and stored at two conditions, 40° and 50°F and 95% RH. Integrated Project Treatment Number * Quality Evaluation Quality Evaluation Date I Date II Dec. 27 1979 Feb. 8 1980 Marketable Potatoes1, Marketable Potatoes1, % good stored at 40° % good stored at 40° 95% RH 95% RH Quality Evaluation Quality Evaluation Quality Evaluation Date V Date IV Date III Mar. 17 1980 Apr. 15 1980 Apr. 15 1980 Marketable Potatoes1, Marketable Potatoes1, Marketable Potatoes1, % good stored at 40° % good stored at 40° % good stored at 40° 95% RH 95% RH 95% RH 1 2 3 4 5 6 7 8 100.0 97.3 94.6 95.6 94.9 94.4 90.1 100.0 9 Av. 89.1 95.1 Marketable Potatoes1, % good stored at 50° 95% RH 1 91.9 2 3 4 5 6 7 8 90.1 100.0 97.3 88.9 88.3 84.1 88.8 94.5 93.4 92.8 98.7 91.4 91.0 90.4 94.4 93.3 93.3 83.8 82.3 89.9 80.8 86.3 88.5 93.8 90.2 87.0 87.0 95.9 94.3 98.5 95.7 96.3 94.3 94.7 98.8 93.8 95.8 93.7 95.1 93.3 91.8 98.3 84.1 93.4 95.8 80.7 84.3 82.6 85.1 81.8 84.4 85.5 86.2 95.9 89.2 90.3 91.1 93.5 94.9 90.9 88.0 100.0 96.7 98.9 98.9 100.0 100.0 94.6 98.6 100.0 98.6 Marketable Potatoes1, % good stored at 50° 95% RH 98.9 99.0 98.8 94.7 96.0 95.1 96.3 94.8 Marketable Potatoes1, % good stored at 50° 95% RHMarketable Potatoes1, % good stored at 50° 95% RHMarketable Potatoes1, % good stored at 50° 95% RHMarketable Potatoes1, % good stored at 50° 95% RH 9 Av. 98.5 92.0 98.8 96.9 *Refer to Table 2 footnotes for description of production treatments. 1Average market quality from 1 sample bag (approximately 25 lbs.) from each treatment 95.5 93.4 77.5 83.1 93.6 91.9 Table 7 Market quality of 1979 Superior potatoes stored in MSU cubicles at 40°F and 95% relative humidity for 256 days. Sample Designation * and Production Treatment ** Replication Replication Replication Replication III IV I II Market Quality, Market Quality, Market Quality, Market Quality, % good % good % good % good Replication V Market Quality, % good Average SWL Av. SWL SS SS Av. 1 2 SWL 3 SWL 4 SWL 5 SWL 6 SWL 7 SWL 8 SWL 9 SWL 1 SS 2 SS 3 SS 4 SS 5 SS 6 SS 7 SS 8 SS 9 97.4 96.4 97.4 97.0 96.4 89.1 97.4 94.4 94.6 empty table cell 93.8 100.0 93.8 93.8 100.0 100.0 100.0 93.3 92.9 empty table cell 100.0 98.6 93.0 93.2 98.5 95.5 95.7 98.6 93.2 94.1 88.2 89.5 88.9 100.0 88.2 100.0 100.0 100.0 93.2 93.3 100.0 94.0 98.4 93.4 94.6 93.3 98.3 94.1 88.2 100.0 88.9 88.9 100.0 100.0 100.0 100.0 100.0 95.5 97.3 97.5 95.1 94.6 94.8 97.4 85.7 100.0 100.0 94.4 88.9 100.0 100.0 93.3 100.0 100.0 96.5 95.5 90.9 100.0 96.4 96.6 100.0 95.1 94.0 empty table cell 100.0 100.0 93.3 94.1 93.3 87.5 93.8 100.0 88.2 empty table cell 97.4 95.9 95.7 96.3 97.0 93.8 96.5 95.8 93.2 95.7 96.4 95.3 94.2 90.9 96.4 95.1 97.4 98.7 96.2 95.6 empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell *Sample bags of Superior potatoes from the 1979 MSU Integrated Potato Project were stored at 40° and 95% RH. SWL potatoes were stored specifically for weight loss determination and SS potatoes were stored for a seed viability determination **Refer to Table 2 footnotes for description of production treatments Table 8 Yield performance of 1979 Superior seed potatoes phosphorus and nematicides, stored at 40°F and 95% RH, and planted May 9, 1980. 1979 1979 Production Production Treatments ** Treatments ** No. P2O5 lbs. 1979 Production Treatments ** Nematicide Yield Specific Gravity Yield Total cwt/A Yield No 1 cwt/A * produced with different levels of Stand % Yield No 1 % 1 2 3 4 5 6 7 8 9 0 0 0 50 50 50 150 150 150 None Temik Vorlex None Temik Vorlex None Temik Vorlex 97 97 95 97 95 94 95 98 98 317 309 305 320 332 331 326 305 303 291 287 287 290 314 317 305 287 280 91.8 92.9 94.1 90.6 94.6 95.8 93.6 94.1 92.4 1.069 1.068 1.068 1.068 1.069 1.066 1.068 1.068 1.067 *The 1979 MSU Integrated Potato Project produced Superior potatoes using various levels of phosphorus and nematicides, representative samples were secured from these plots, stored, and planted in 1980 to study the influence of production treatments on seed vigor **Refer to Table 2 footnotes for description of production treatments Another measure of potato quality is seed viability or yield perfor­ mance. One sample bag of potatoes was taken at random from each of the five replications of each of the nine treatments (45 sample bags, approximately 25 lbs each). These potatoes were stored in the MSU cubicles at 40° after suberization. On May 8, 1980 these potatoes were evaluated and 12 tubers each of the 5 replications of the 9 treatments were provided to Dr. Richard Chase for planting. Table8 presents the yield performance data. There is a range in total yield 303 to 332 cwt/A and yield of No. 1 potatoes ranges 280 to 317 cwt/A but it is not apparent that this difference is attribu­ table to the nine production treatments. The specific gravities were all low and ranged from 1.066 to 1.069. QUALITY OF STORED POTATOES DUE TO HANDLING, PRESTORAGE TREATMENTS, AND STORAGE ENVIRONMENTS Dept. of Agricultural Engineering, Michigan State University B.F. Cargill * INTRODUCTION: . Monona potatoes grown commercially and under one of the recommended MSU Integrated project treatments (repeating a 1978 treatment) will be used for this phase of the storage project. These potatoes will be used for evaluation of various prestorage handling and chemical treatments and storage environ­ ments in controlled environment cubicles and in the center of a bulk pile of commercially stored potatoes. OBJECTIVE: Note: (1) To determine the influence of prestorage treatments (bacte/fungicides (2) To monitor equivalent potatoes stored in the center of a bulk pile of and sprout inhibitors) on bruised potatoes after extended storage under various storage environmental conditions. commercially stored potatoes. It is surmised that more air than necessary is recommended in bulk- stored potatoes but data is not available to enable reduced volume recommendations. This research is designed to eventually enable the development of a storage operational system which will be activated by the requirements of the "potato” and not by man. This ultimately will reduce fan time and storage operational costs for electricity. PROCEDURE: This phase involved three aspects: 1) mechanical harvesting and handling, 2) post harvest treatment and 3) storage location of Monona potatoes. The pur­ pose was to determine the effects of handling and prestorage chemical treatments on weight loss and marketable quality of potatoes out of storage. Two lots of Monona potatoes were used. One lot of Monona potatoes was grown on the MSU Potato Research Farm; the second lot was grown on a-commer­ cial potato farm in Montcalm County (near Edmore). The MSU potatoes were harvested with the MSU plot harvester. One half of this lot was rerun over a windrower twice to simulate additional mechanical handling. The windrower was operated at a PTO speed of 800 rpm. The Monona potatoes on this commercial farm were dug with a two row windrower and six rows were harvested at one time with a John Bean Air Harvester. Three lots of pota­ toes were treated, stored and evaluated: a) hand selected potatoes out of the windrow, b) sample bags were filled directly from the end of the bin piler and c) one half of the hand selected potatoes from the windrower were twice rerun over the windrower (3x bruise). Thus the handling variables were: *Other Researchers contributing to the Project: Dr. H.S. Potter, Dept. of Botany and Plant Pathology, Dr. J.N. Cash, Dept. of Food Science and Human Nutrition, Dr. Richard Chase, Dept. of Crop and Soil Sciences MSU Grown Monona Potatoes 1) Minimum bruise - MSU plot harvester (lx bruise). 2) Bruised (3x) rerun over the windrower (2 times). Commercially grown and harvested Monona 1) Minimum bruise - hand selected from the windrow (lx bruise). 2) Sample obtained directly from the end of the bin piler 3) Hand selected potatoes from windrow were rerun (2 times) over the windrower (3x bruise). These two lots of Monona potatoes were prestorage treated with a calibrated system mounted on a conveyor (to simulate prestorage application of chemicals prior to storage. Bruised and non-bruised potatoes from each lot were prestorage treated as follows: Check - no chemical Chlorine TBZ - Mertec applied at approved rate per ton TBZ & chlorine - both chemicals were applied in the same solution 1. Potatoes - (a) MSU Research farm potatoes of the Monona variety will be grown using one of the recommended production treatments from the 1978 MSU Integrated potato project. These potatoes will be subjected to a 3 x bruise by re-running tubers over a commercial potato wind- rower. (b) Monona potatoes from a commercial grower will be collected and pre storage treated similar to the MSU potatoes. 2. Storage - The MSU as well as the commercially grown Monona potatoes will be stored in the MSU controlled environment cubicles and in the center of the bulk pile of commercially grown and stored Monona po­ tatoes. 3. Storage Environment - (a) MSU potatoes will be stored in cubicles at 40° and 50 °F and 95% R.H. (after suberization) and in the center of the bulk pile of commercially stored potatoes. (b) The commercially grown Monona potatoes will be bagged, tagged, treated, and weighed. Potatoes will be placed in the MSU cubicles at- 40° and 50° F and in the center of the bulk pile of commercially stored potatoes (along with the MSU potatoes). This arrangement is being made to observe the potential storability quality difference between the cubicle and bulk storage environment. 4. Bulk Storage Environment - Temperature and relative humidity monitoring instrumentation will be placed in the pre-storage treated MSU and com­ mercially grown potatoes in the bulk storage pile. The instrumentation will enable continuous monitoring of temperature and R.H. throughout the entire depth in the bulk storage. 5. Weight Loss - Weight loss data will be taken at harvest, after suber­ ization, and monthly thereafter until June, 1980 for the cubicle-stored potatoes. Similar weight loss data will be taken at harvest and upon removal of potatoes from the commercial bulk storage. 6. Tuber Quality - A bruise-free evaluation will be made at harvest by Ore- Ida (before and after bruising). Tuber quality evaluations will be made every other month until June, 1980 on cubicle-stored potatoes and upon emptying the bulk storage. 7. Chipping Quality - Chip quality will be checked just prior to storage and every other month until June, 1980 on cubicle-stored potatoes and upon removal of test potatoes from the bulk storage. DISUCSSION AND RESULTS: Weight loss data for Monona potatoes is shown in Tables 1 to 4 and Figs. 1 and 2. Monona potatoes were harvested on the MSU Potato Research Farm and on a commercial potato farm. These potatoes were mechanically and chemically treated and stored in the MSU cubicles at 40° and 50 F and in the center of a pile in a commercial storage. Tables 1 and 2 show the weight loss data for these two lots of Monona (bruised and non-bruised; treated and checks) stored at 40° and 50°F; the weight loss factor for these is as follows: Storage Period Days Weight Loss Factor wt loss/day, % 50°F Bruised Weight Loss Factor wt loss/day, % 50°F Non-Bruised Weight Loss Weight Loss Factor Factor wt loss/day, % wt loss/day, % 40°F 40°F Bruised Non-Bruised 77 126 145 187 231 .047 .040 .042 .049 .061 .038 .032 .036 .045 .059 .052 .043 .042 .042 .042 .042 .036 .034 .034 .035 TreatmentsWeight Loss Additional weight loss data for the two lots of bruised and non­ bruised Monona potatoes is shown in Tables 3 and 4. Table 3 is data for a storage of 145 days at 50°F in MSU cubicles and Table 4 is for 150 days at approximately 48°F in the center of the pile in a commercial storage. As was demonstrated for the second year, there is less weight loss in the center of the pile than from the sample bags stored in the MSU cubicles at 95% RH. An analysis of the data for 1979 potatoes shown in Tables 3 and 4 follows: Weight Loss Weight Loss Weight Loss Weight Loss Weight Loss Weight Loss Factor Factor Factor Factor Factor Factor Factor wt loss/day, % wt loss/day, % wt loss/day, % wt loss/day, % wt loss/day, % wt loss/day, % wt loss/day, % Non-Bruised Non-Bruised Non-Bruised Bruised Bruised Bruised Bruised Lot 1 Aver. Lot 2 Lot 3 Lot 4 Lot 5 Aver. 145 days at 50°F 145 days at 50°F 145 days at 50°F 145 days at 50°F 145 days at 50°F 145 days at 50°F 145 days at 50°F in MSU cubicles in MSU cubicles in MSU cubicles in MSU cubicles in MSU cubicles in MSU cubicles in MSU cubicles .033 .034 .040 .045 .044 .040 .037 .038 .048 .041 150 days at 48°F 150 days at 48°Fin commercial storage150 days at 48°Fin commercial storage150 days at 48°Fin commercial storage150 days at 48°Fin commercial storage 150 days at 48°Fin commercial storage in commercial storage .023 .023 .027 .025 Check .036 Treated .034 150 days at 48°F in commercial storage Check Treated .047 .036 .023 .026 .025 .030 .027 .025 .027 .029 .026 .028 150 days at 48°F in commercial storage Table 1 Influence of pre-storage mechanical and chemical treatments and storage duration on weight loss from two plots of 1979 Monona potatoes stored in MSU cubicles at 40°F and 95% relative humidity. Sample * Number & Pre-storage Treatments Storage Period, days 261 % Weight Loss Storage Period, Storage Period, Storage Period, Storage Period, Storage Period, days days days days days 2315 771 1262 1453 1874 % Weight Loss % Weight Loss % Weight Loss % Weight Loss % Weight Loss MMO 40F NS MMO 40F NC MMO 40F NT NA MMO 40F MMO 40F Av. MMO 40F BS MMO 40F BC BT MMO 40F BA MMO 40F MMO 40F Av. CMO 40°F WS CMO 40°F WC CMO 40°F WT WA CMO 40°F CMO 40°F Av. CMO 40°F PS CMO 40°F PC CMO 40°F PT PA CMO 40°F CMO 40°F Av. CMO 40°F BS CMO 40°F BC BT CMO 40°F CMO 40°F BA Av. CMO 40°F Av. Non- Bruised Av. Bruised 1.9 2.0 2.0 1.9 2.0 2.9 2.8 2.8 2.8 2.8 2.3 2.6 2.4 2.1 2.4 3.0 3.2 3.2 2.4 3.0 2.9 2.7 3.0 2.8 2.9 2.2 2.9 2.9 2.9 3.3 2.8 3.0 3.8 3.7 4.0 3.7 3.8 3.3 3.4 3.4 3.3 3.4 4.0 4.4 4.3 3.6 4.1 4.0 3.9 4.0 3.9 4.0 3.2 4.0 4.5 4.2 4.2 3.9 4.2 5.2 5.4 5.3 4.7 5.2 4.8 4.8 4.7 4.3 4.7 5.5 5.6 6.1 5.0 5.6 5.5 5.3 5.6 5.5 4.6 5.4 - 4.7 5.2 4.9 4.3 4.8 5.3 5.6 5.7 5.5 5.5 5.6 5.1 4.9 5.0 5.2 6.0 6.6 7.0 5.7 6.3 5.9 6.8 6.6 7.0 6.6 5.0 6.1 6.7 7.3 6.5 5.3 6.5 6.5 - 7.0 6.3 6.6 6.9 6.1 6.3 5.9 6.3 7.7 9.6 8.3 7.4 8.3 7.8 9.2 9.0 8.6 8.7 6.4 7.9 8.0 8.9 8.5 6.7 8.0 8.2 - 8.5 8.1 8.3 8.5 7.7 8.4 7.9 8.1 9.6 11.6 9.8 9.0 10.0 9.9 10.8 10.7 10.3 10.4 8.1 9.6 Table 1 con’t. *Lettercodes for samples Two potato lots —- harvested October 4, 1979 Lot MMO - Monona Potatoes grown on the MSU Montcalm Potato Research Farm at Entrican, Michigan. Lot CMO - Monona potatoes grown on a commercial Montcalm County potato farm at Edmore, Michigan. Mechanical Treatments N Non-bruised - MSU potatoes harvested with MSU plot harvester. B Bruised 3x - plot harvested potatoes intentionally mechanically bruised by rerunning potatoes twice over a windrower operated at a PTO speed of 800 rpm, MMO-B. W Hand-selected potato samples from commercially windrowed potatoes. P Potato samples from same field but obtained off the end of the piler. B CMO-B are W potato samples bruised by rerunning twice over windrower like MMO-B above. Chemical Treatments S Check lot no chemical treatment C Chlorine only T Mertec (TBZ) only A Both TBZ and chlorine 1Average weight loss from 5 sample bags-—sample bags approximately 25 lbs. each. 2Average weight loss from 4 bags. 3Average weight loss from 3 bags.4 Average weight loss from 2 bags. 5Average weight loss from 1 bag. Table 2 Influence of pre-storage mechanical and chemical treatments and storage duration on weight loss from two plots of 1979 Monona potatoes stored in MSU cubicles at 50°F and 95% relative humidity. Sample * Number & Pre-storage Treatments Storage Period, Storage Period, Storage Period, Storage Period, Storage Period, Storage Period, days days days days days days 2315 261 771 1262 1453 1874 % Weight Loss % Weight Loss % Weight Loss % Weight Loss % Weight Loss % Weight Loss MMO 50°F NS MMO 50°F NC MMO 50°F NT NA MMO 50°F Av. MMO 50°F MMO 50°F BS MMO 50°F BC MMO 50°F BT BA MMO 50°F MMO 50°F Av. CMO 50°F WS CMO 50°F WC WT CMO 50°F CMO 50°F WA CMO 50°F Av. CMO 50°F PS CMO 50°F PC CMO 50°F PT PA CMO 50°F Av. CMO 50°F CMO 50°F BS CMO 50°F BL CMO 50°F BT CMO 50°F BA CMO 50°F Av. Non- Av. Bruised Av. Bruised 1.5 1.5 1.3 1.2 1.4 2.0 1.9 2.5 1.2 1.9 1.1 2.2 2.2 1.9 1.9 1.9 1.5 2.1 1.9 1.9 2.7 2.4 2.3 1.9 2.3 1.6 2.0 2.8 2.6 2.0 3.4 2.7 3.4 3.3 3.8 2.7 3.3 2.5 3.2 3.4 3.3 3.1 3.5 3.0 3.6 3.7 3.5 3.9 4.3 3.7 3.9 4.0 2.9 3.6 4.1 3.5 2.8 4.8 3.8 5.9 4.0 4.8 4.5 4.8 3.9 4.9 4.3 4.3 4.4 5.1 3.9 4.7 4.9 4.7 5.4 5.6 5.3 5.8 5.5 4.1 5.0 5.2 4.0 4.1 6.8 5.0 6.9 5.4 6.6 4.5 5.9 4.8 6.1 5.5 5.7 5.5 6.7 4.9 4.9 5.7 5.6 6.5 7.3 5.7 7.8 6.8 5.2 6.1 8.3 7.2 8.3 9.7 8.4 11.4 8.3 8.8 8.6 9.3 8.9 9.0 7.7 8.4 8.5 9.8 10.2 7.1 8.3 8.9 9.6 10.7 8.9 8.1 9.3 8.4 9.2 12.7 12.8 13.4 15.0 13.5 16.5 13.8 13.7 12.8 14.2 16.9 13.5 12.2 13.4 13.8 15.1 15.3 12.5 12.3 13.8 14.8 16.0 15.1 12.2 14.5 13.6 14.2 Table 2 con’t. *Lettercodes for samples Two potato lots — harvested October 4, 1979 Lot MMO - Monona potatoes grown on the MSU Montcalm Potato Research Farm at Entrican, Michigan. Lot CMO - Monona potatoes grown on a commercial Montcalm County potato farm at Edmore, Michigan. Mechanical Treatments N Non-bruised - MSU potatoes harvested with MSU plot harvester. B Bruised 3x - plot harvested potatoes intentionally mechanically bruised by rerunning potatoes twice over a windrower operated at a PTO speed of 800 rpm, MMO-B. W Hand-selected potato samples from commercially windrowed potatoes. P Potato samples from same field but obtained off the end of the piler. B CMO-B are W potato samples bruised by rerunning twice over windrower like MMO-B above. Chemical Treatments S Check lot no chemical treatment C Chlorine only T Mertec (TBZ) and chlorine A Both TBZ and chlorine 1Average weight loss from 5 sample bags—sample bags approximately 25 lbs. each. 2Average weight loss from 4 bags. 3Average weight loss from 3 bags. 4Average weight loss from 2 bags. 5Average weight loss from 1 bag. Table 3 Summary of weight loss data* Monona potatoes stored in MSU cubicles at 50°F and 95% RH for 145 days. *See Table 2 Post Harvest Chemical Treatment Non-bruised lots ** Bruised lots Non-bruised lots ** ** Lot 1 Lot 1 Lot 3 Bruised lots ** Lot 4 for bruised and non-bruised potatoes from two lots of Bruised lots ** Lot 5 Check Chlorine TBZ TBZ & Chlorine 5.2 4.0 4.1 6.8 4.8 6.1 5.5 5.7 6.7 4.9 4.9 5.7 6.9 5.4 6.6 4.5 6.5 7.3 5.7 7.8 **Lot 1 MSU grown Monona harvested with MSU plot harvester Lot 2 Monona potatoes commercially grown in Montcalm County and windrowed—potatoes Lot 3 Commercially grown and harvested with the John Bean harvester—potatoes were Lot 4 Lot 1 potatoes rerun two times by a windrower operating with PTO at 800 rpm Lot 5 Lot 2 potatoes rerun as was Lot 4 hand selected out of the windrow bagged off the end of the bin piler Table 4 of weight loss data for bruised and non-bruised potatoes from two lots of * Summary Monona potatoes stored in the center of a commercial pile of potatoes at 48°F for 150 days. *See Table 2 Post Harvest Chemical Treatment Bruised lots Non-bruised lots ** Non-bruised lots ** ** Lot 1 Lot 2 Lot 3 Bruised lots ** Lot 4 Bruised lots ** Lot 5 Check Chlorine TBZ TBZ & Chlorine 3.5 4.3 3.9 3.9 3.5 3.7 3.6 4.1 3.8 4.1 4.3 5.0 4.1 3.7 3.6 3.8 4.1 4.7 3.9 4.3 **Lot 1 MSU grown Monona harvested with MSU plot harvester Lot 2 Monona potatoes commercially grown in Montcalm County and windrowed—potatoes Lot 3 Commercially grown and harvested with the John Bean harvester—potatoes were Lot 4 Lot 1 potatoes rerun two times by a windrower operating with PTO at 800 rpm Lot 5 Lot 2 potatoes rerun as was Lot 4 hand selected out of the windrow bagged off the end of the bin piler Fig. 1. "Best Fit” line representing weight loss due to handling and post harvest chemical treatments on 1979 Monona potatoes grown on the MSU Potato Research Farm and stored in the center of a commercial potato bin at 48° for 150 days. Fig. 2. "Best Fit" line representing weight loss due to mechanical handling and post harvest chemical treatments on 1979 Monona potatoes grown in Montcalm County Michigan and stored in the center of a commercial potato bin at 48°F for 150 days. Weight loss in relationship to handling and post storage chemical treatments needs additional research. Post harvest treatment chemicals appear to have a negative effect upon weight loss in relationship to the non-treated check in spite of the fact the check received the same handling (without chemical applications). Figures 1 and 2 are best fit lines representing the data in Tables 3 and 4 . In Figures 1 and 2 bruised, treated pota­ toes show slightly less weight loss than non-bruised and windrowed potatoes. Research in progress for 1980 may help clarify this point. The two lots of Monona potatoes were evaluated for the effects of mechanical handling and post harvest chemical treatments on out- of-storage market quality. Non-bruised, mechanically harvested, and intentionally bruised Monona potatoes were treated with com­ binations of Mertec and chlorine and stored in MSU cubicles and in the center of the pile of a commercial storage. Data represent­ ing market quality are shown in Tables 5 and .6 and Figures 3 to 6. Tables 5 and 6 show bruised and non-bruised stored at 40° and 50°F in the MSU cubicles. These tables show that pre-storage chemical treatments are more effective on up-grading the market quality of bruised versus non­ bruised potatoes. In general non-bruised, non-treated potatoes are at about the same grade as bruised and treated potatoes stored under equivalent conditions. Figures 3 and 4 are a graphic presentation of the effect mechanical damage has upon market quality; these figures also dramatically show the beneficial effects of Mertec and chlorine on improving market quality. Figure 3 graphically presents the picture for MSU plot harvested potatoes and intentionally rebruised and Figure 4 presents the picture for commercially harvested Monona potatoes (harvested under ideal conditions); the bruised line in Figure 4 is data for windrowed potatoes that were intentionally rebruised like Figure 3. Figures 5 and 6 graphically present the picture of market quality degradation due to: 1. Storage duration 2. Storage temperature 3. Mechanical handling Figure 5 represents the effect storage duration and temperature and bruising have on market quality of MSU Monona potatoes stored in the MSU cubicles. Figure 6 represents the effect of storage duration on commercially grown and harvested Monona potatoes. Table 5 Influence of pre-storage mechanical and chemical treatments and storage duration on marketable quality of 1979 Monona potatoes stored in MSU cubicles at 40°F and 95% relative humidity. Sample * Number & Pre-storage Treatments MMO MMO Av. CMO Av. CMO CMO Av. CMO CMO CMO Av. MMO Av. MMO NS MMO NC MMO NT MMO NA WS CMO WC CMO WT CMO WA PS CMO PL CMO PT CMO PA BS CMO BC CMO BT CMO BA BS MMO BC MMO BT MMO BA Avg. Non- Bruised Av. Bruised Storage Period, days Storage Period, days 84 127 Marketable Quality, Marketable Quality, % Good ** ** % Good Storage Period, days 154 Marketable Quality, % Good ** Storage Period, days 286 Marketable Quality, % Good ** 87.7 91.8 90.3 90.4 90.1 82.8 80.1 90.0 92.3 86.4 83.5 89.0 89.1 89.5 87.8 66.2 62.7 78.7 72.2 70.0 72.0 66.2 84.6 56.6 70.2 88.2 76.0 93.5 84.2 100.0 92.7 92.6 93.3 91.1 98.3 97.0 94.9 89.4 81.7 94.8 95.9 90.5 62.9 65.5 85.1 88.1 75.4 83.3 80.5 93.9 90.1 87.0 93.8 77.6 62.9 93.7 97.0 88.4 85.5 65.0 75.0 97.1 92.2 82.3 60.5 80.8 88.4 93.2 80.7 31.0 65.5 100.0 80.8 69.3 76.8 82.3 80.8 78.0 83.9 76.0 -- 100.0 94.2 91.0 93.3 94.6 100.0 100.0 93.2 93.8 96.8 85.6 88.2 97.0 — 90.0 69.8 80.3 87.5 73.2 77.7 69.4 61.6 68.0 85.0 71.0 95.7 78.0 Table 5 con’t. *Lettercodes for samples Two potato lots — harvested October 4, 1979 Lot MMO - Monona potatoes grown on the MSU Montcalm Research Farm at Entrican, Michigan Lot CMO - Monona potatoes grown on a commercial Montcalm County potato farm at Edmore, Michigan. Mechanical Treatments N Non-bruised - MSU potatoes harvested with MSU plot harvester B Bruised 3x - plot harvested potatoes intentionally mechanically bruised by rerunning potatoes twice over a windrower operated at a PTO speed of 800 rpm, MMO-B. W Hand-selected potato samples from commercially windrowed potatoes. P Potato samples from same field but obtained off the end of the piler. B CMO-B are W potato samples bruised by rerunning twice over windrower like MMO-B above. Chemical Treatments S Check lot no chemical treatment C Chlorine only T Mertec (TBZ) only A Both TBZ and chlorine **Average marketable quality from 5 sample bags — sample bags approximately 25 lbs. each. Table 6 Influence of pre-storage mechanical and chemical treatments and storage duration on marketable quality of 1979 Monona potatoes stored in MSU cubicles at 50°F and 95% relative humidity. Sample * Number & Pre-storage Treatments MMO MMO Av. CMO CMO Av. CMO CMO Av. CMO CMO Av. MMO MMO Av. NS NC MMO NT MMO MMO NA WS CMO WC WT CMO CMO WA PS CMO PC PT CMO PA CMO BS BC CMO BT CMO CMO BA BS BC MMO BT MMO MMO BA Av. Non- Bruised Av. Bruised Storage Period, days Storage Period, days 84 127 Marketable Quality, Marketable Quality, % Good ** ** % Good Storage Period, days 154 Marketable Quality, % Good ** Storage Period, days 286 Marketable Quality, % Good ** 91.8 89.4 89.0 79.7 87.5 91.5 84.2 87.1 80.4 85.8 88.0 80.7 77.8 85.5 83.0 65.1 63.9 89.2 63.0 70.3 61.0 72.5 70.5 70.0 68.5 86.6 73.9 89.9 92.2 93.2 88.2 90.9 95.0 92.3 93.9 90.7 93.0 93.7 79.3 96.0 94.9 91.0 58.8 78.3 85.2 74.1 73.3 76.1 89.9 93.1 83.1 91.9 82.7 -- 57.6 87.9 91.6 90.2 81.5 74.0 89.1 92.8 95.4 87.8 67.3 77.3 91.6 85.7 80.4 54.8 60.3 70.3 79.3 66.2 59.0 65.0 77.1 81.2 70.6 84.6 80.3 88.1 81.8 88.5 95.5 88.5 81.6 59.1 .77.6 90.7 77.3 81.9 82.7 69.1 75.3 77.3 63.9 36.5 50.0 46.2 49.2 58.4 40.0 66.7 54.0 54.8 82.9 60.4 Table 6 con’t. *Lettercodes for samples Two potato lots — harvested October 4, 1979 Lot MMO - Monona potatoes grown on the MSU Montcalm Research Farm at Entrican, Michigan. LOT CMO - Monona potatoes grown on a commercial Montcalm County potato farm at Edmore, Michigan. Mechanical Treatments N Non-bruised - MSU potatoes harvested with MSU plot harvester B Bruised 3x - plot harvested potatoes intentionally mechanically bruised by rerunning potatoes twice over a windrower operated at a PTO speed of 800 rpm, MMO-B. W Hand-selected potato samples from commercially windrowed potatoes. P Potato samples from same field but obtained off the end of the piler. B CMO-B are W potato samples bruised by rerunning twice over windrower like MMO-B above. Chemical Treatments S Check lot no chemical treatment C Chlorine only T Mertec (TBZ) only A Both TBZ and chlorine ** **Average marketable quality from 5 sample bags — sample bags approximately 25 lbs. each. Fig. 3. "Best Fit" line representing market quality loss as influenced by handling of 1979 MSU grown Monona potatoes stored in the center of a commercial potato storage at 48°F and evaluated March 10, 1980. Fig. 4. "Best Fit" line representing market quality loss as influenced by a commercial grower handling of 1979 commercially grown Monona potatoes stored in the center of a commercial potato storage at 48°F and eval­ uated March 10, 1980. Fig. 5. "Best Fit" line representing market quality loss as influenced by handling and storage duration of 1979 MSU grown Monona potatoes stored in MSU cubicles at 40° and 50°F and 95% RH and evaluated at various times during the storage season. Fig. 6. "Best Fit" line representing market quality loss as influenced by commercial handling and storage duration of 1979 commercially grown Monona potatoes stored in MSU cubicles at 50°F and 95% RH and eval­ uated at various times during the storage season. Supplemental Discussion (information on air flow distribution in a commercial potato storage). One aspect of the 1979 Potato Storage Research not specified in the 1979 objectives was uniformity of air flow distribution through the entire potato pile in the commercial storage. The reason for this concern was that in 1978 the research potatoes for the 1978 project were placed in the commercial bin in a layer one sample bag deep at a pile depth of 6 feet. Sample bags were placed at three locations across the storage at the 6 foot depth (over the main, in the center, and at the side opposite the main). In 1978 this commercial storage was filled with quality Monona potatoes plus the research potatoes. It was reported later, however, that losses were always observed along the main, in the area of the fan house, and at the unloading end. By April 1979 it was obvious the grower would lose this entire bin of Monona potatoes for chips plus the research potatoes in the center of the pile. After the storage was emptied and cleaned, an intensive air flow distribution analysis was made of this commercial storage bin. The air distribution was found to be very uneven with extreme shortages of air in one-fourth to one- third of the bin along the side over the main; drastic air shortages occurred from the first three lateral ducts (this is the area around the fan house and the unloading door). The areas where air shortages occurred were the areas where losses normally were excessive. Extensive air velocity and static pressure measurements were made throughout the entire air distribution system. Air velocities out of the air slots of ducts #1, 2, and 3 (at the fan end) were less than the 200 fpm (feet per min­ ute) to which the instrumentation would respond. However, air velocities out of the slots in the laterals in the opposite end were 2500 fpm in the center and along the side opposite the main. The instrumentation would not respond to slot air flow along the entire main for a distance of 7’ to 8’ from the side wall of the bin. The storage air flow system was balanced so that all slots had an air velocity of 1000 fpm ± 100 fpm. The bin was filled in 1979 with commercially grown Monona potatoes and the 1979 research potatoes were placed in the center of the pile as reported earlier (over the main, in the center and on the side opposite the main—-all at a depth of 6 feet). The storage was maintained by the grower and unloaded the week of March 9, 1980. The research potatoes (MSU grown Monona and the commercially grown and harvested Monona poatotes) were evaluated for weight loss and market quality as reported earlier in this report. The grower sold all the potatoes from this bin for chips. The potato bag samples in the three locations across the bin were evaluated and compared as to the effect of location. There was no weight loss or quality difference of equivalent potatoes located over the main, in the center, or from the side opposite the main. Uniform air distribution through the pile throughout the entire storage is essential for the quality storage of potatoes for the chip market. CORN HYBRIDS, PLANT POPULATION AND IRRIGATION E. C. Rossman and Keith Dysinger Department of Crop and Soil Sciences Performance data for 71 commercial com hybrids evaluated in 1980 with and without irrigation are presented in Table 1 along with two and three year averages for those tested in 1979 and 1978. 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. Only three inches of supplemental water was applied during July and August since rainfall was much more favorable than normal during this period in 1980. Irrigated yields averaged 11.6 bushels more than nonirrigated — 125.8 vs 114.2, an increase of 10%. Hybrids ranged from 73.7 to 167.8 bushels per acre with irrigation and 65.1 to 158.5 without irrigation. Hybrids significantly better than average yield (arranged in order of increasing grain moisture con­ tent at harvest) are listed below. Nineteen of the 24 hybrids were in the highest yielding group for both irrigated and unirrigated plots. Irrigated Pioneer 3901 (2X) Voris X401 (2X) Michigan 3102 (2X) Hyland HL-2448 (2X) Great Lakes GL-455 (2X) Asgrow RX511 (2X) Jacques JX97 (2X) Amcorn ZX5500 (2X) Wolverine W166 (2X) Golden Harvest XS715 (2X) Michigan 407-2X (2X) Jacques JX147 Great Lakes GL-477 (2X) Super Crost 2350 (2X) Pioneer 3780 (2X) Blaney B507 (2X) Migro HP23R (2X) Pride 4488 (2X) Blaney B606 (2X) Michigan 5922 (2X) ADI 323 (2X) ADI 197 (2X) Migro M-2018X (2X) Golden Harvest H-2500 (2X) Not Irrigated Amcorn Exp. 4 (2X) Pioneer 3901 (2X) Voris X401 (2X) Michigan 3102 (2X) Hyland HL-2448 (2X) Dairyland DX1096 (2X) Great Lakes GL-455 (2X) Asgrow RX511 (2X) DeKalb XL14aa (2X) Jacques JX97 (2X) Wolverine W166 (2X) Michigan 407-2X (2X) Great Lakes GL-477 (2X) Super Crost 2350 (2X) Pioneer 3780 (2X) Blaney B507 (2X) Migro HP23R (2X) Pride 4488 (2X) Blaney B606 (2X) Michigan 5922 (2X) ADI 323 (2X) ADI 197 (2X) Migro M-2018X (2X) Golden Harvest H-2500 (2X) The correlation of irrigated with unirrigated yields was highly significant, .812, indicating that the hybrids tended to respond alike in both situations. During the 13-year period, 1968-1980, the correlations have ranged between .7 and .9 except for 1976 when it was .490. All correlations have been highly sig­ nificant. Average, highest and lowest yields for corn hybrids irrigated and not irrigated for the 13-year period, 1968-1980, are given in Table 2. The average yielding hybrids have yielded 46 more bushels when irrigated. The highest yielding hybrids have responded with 59 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 maximize returns from irri­ gation with little, if any, additional cost. There was no consistent difference in stalk lodging between irrigated and unirrigated plots in 1980, 15.3% vs. 14.9% (Table 1). 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 susceptibale to lodging. In 1980, the highest lodging was 35% stalk breakage when irrigated and compared to 39% when unirrigated. The lowest lodging was only 0.7% irrigated and 1.5% unirrigated. PLANT POPULATION X IRRIGATION Five adapted hybrids at four plant populations irrigated and not irrigated have been grown in each of 13 years, 1968-1980, Table 3. Over the 13-year period, a population of 23,300 has given the highest average yield (167 bushels per acre) when irrigated while 19,200 has given the highest yield (110 bushels) without irrigation. The 23,300 population irrigated has given the highest yield in 11 out of 13 years (1973 and 1979 being the exceptions). The 13-year average in­ crease due to irrigation has been 67 bushels per acre at the 23,300 population. Moisture content of grain at harvest has averaged .5 - 1.0% higher for the higher populations. Stalk lodging has increased with increased plant populations. Table 1 Hybrid (Brand-Variety) Blaney B100E (2X) Golden Harvest XS-824 (2X) Great Lakes GL-352 (Sp.) Blaney B101 (2X) Jacques JX44 (2X) Michigan 333-3X (3X) Michigan 280 (4X) Dairyland DX1095 (2X) Migro M-0101 (2X) Pioneer 3950 (MSX) Warwick W901 (2X) Migro HP16 (2X) +Amcorn Exp. 4 (2X) *+Pioneer 3901 (2X) *+Voris X401 (2X) *+Mlchigan 3102 (2X) *+Hyland HL-2448 (2X) Super Crost 1950 (MSX) Super Crost 1700 (MSX) Great Lakes GL-422 (2X) Pioneer 3958 (2X) +Dairyland DX1096 (2X) Wolverine W126 (2X) Custom CFSE2004 (2X) Custom CFS1000 (2X) NORTH CENTRAL MICHIGAN Zone 3 Montcalm County Trial - Irrigated vs. Not Irrigated One, Two, Three Year Averages - 1980, 1979, 1978 % Stalk lodging % Stalk lodging % Stalk lodging % Stalk lodging % Stalk lodging Bushels per acre % Moisture % Moisture % Moisture Bushels per acre Bushels per acre Bushels per acre Bushels per acre Bushels per acre % Stalk lodging 3 Years 3 Years 2 Years 2 Years 1980 1980 3 yrs. 2 yrs. 1980 1980 2 years 2 years 3 Years 3 years 1980 Not Irrig Not Irrig Not Irrig Irrig Irrig Irrig Not Irrig Irrig Not Irrig Irrig Not Irrig Irrig -- 21.1 21.3 -- -- 21.5 21.7 -- 22.1 -- 23 22.2 22.4 23 22.4 23 -- 22.8 23 22.8 23 22.8 -- -- 23.1 24 23.1 -- 23.4 24 23.4 -- -- -- -- -- -- 22 21 22 -- -- -- 23 -- -- 73.7 66.8 86.6 81.3 65.1 74.5 76.0 69.3 -- 82.4 75.9 -- -- -- -- -- -- -- -- -- -- -- -- 106 .6 98.1 93.3 91.7 91.4 80.4 114.8104.5 112.5103.7 104 92 92 108 112 81 72 66 84 82 107.091.5 -- 99.5 89.8 102 -- 132.7129.7 152.2138.4 144 -- -- 147.7130.3 -- 75 -- 117 23.4 24 23.4 -- 23.4 24 23.4 -- 23.4 -- 144.4 138.0 23 -- 151.1132.1 23 112.4107.1 -- 83.6 -- 129.9116.9 -- 77.6 128 104 -- -- 111 82 -- -- -- 23 -- 101.397.6 105 137.5133.1 23.5 24 23.5 -- 23.5 -- -- 117.5100.4 -- 23.7 -- -- 136.9117.8 -- 23.7 113 98.4 88.3 24 26 85 -- -- -- -- -- -- 84 119 -- 114 92 -- 118 -- -- -- -- 151 -- 146 -- 130 -- -- 112 -- -- -- -- -- -- 83 71 -- 83 -- -- -- -- 111 -- 104 -- 87 -- -- 18.6 16.0 31.4 21.2 22.3 21.1 25.5 18.2 21.8 28.6 -- -- -- -- -- 16.1 20.5 25.5 12.0 12.2 7.8 9.9 19.4 13 20.0 19 18.8 20 11 11 23.4 20.1 -- 16.7 15 13.3 12.0 8.9 -- 8.3 8 -- 19.9 19.0 8.4 -- -- -- -- ---- -- 15 17 13 -- 11 8 -- 16 -- -- 7 -- -- -- -- 10 16 9 -- -- -- 5 -- -- -- -- -- -- 11 15 -- 7 -- -- -- -- 5 -- 16.3 12 14.5 -- 4.3 5.0 21.6 18.4 18 -- 9.8 10.1 15.3 -- 9.2 12 9 9 -- -- -- 13 15 17 -- -- -- -- -- -- 87 5.1 14.9 -- 11.1 11.1 8.5 8.5 10.3 7.1 28.8 25.2 -- -- 82 11 7 -- -- -- -- 17 -- -- -- 14 8 6 -- -- -- -- 11 -- 14 -- -- -- -- -- Wolverine W132 (2X) Garno S-90 (2X) *+Great Lakes GL-455 (2X) *+Asgrow RX511 (2X) Garno S-94 (2X) 24 23.7-- -- 23.8 23 23.9-- -- 24.2-- -- 24.2-- -- -- 106 79.876.7 124.1`119.7 124 130 152.5 133.5 -- -- -- 146.7 128.1 -- -- -- -- 128.6 119.1 -- -- +DeKalb XL14aa (2X) Funk G-4256 (3X) *+Jacques JX97 (2X) ADI 232 (2X) *Amcorn ZX5500 (2X) *+Wolverine W166 (2X) Funk G-4224 (MSX) *Golden Harvest XS715 (2X) *+Michigan 407-2X (2X) Great Lakes GL-511 (2X) -- 24.3-- -- 130.4 130.7 24.3-- -- 104.2 94.7 140.2 134.3 -- 24.3-- -- 24.325 24 117.5 107.7 140.1 123.4 -- 24.4-- -- 24.6-- -- 24.6 25 24 24.7-- -- 24.7 24 24.8-- 141.2 133.6 109.9 102.6 141.3 124.0 139.2 139.1 137.7 123.3 -- 25 -- 126 -- -- -- -- -- -- 92 138 -- -- -- -- -- 81 110 -- -- 136 -- 112 -- -- 120 -- 144 -- Amcorn PSX73OO (2X) Dairyland DX1004 (2X) *Jacques JX147 *+Great Lakes GL-477 (2X) Migro HP20 (2X) 27 24.9 24.9-- 25.0-- 25.0 -- 25.0 27 26 -- -- -- -- 125 127.6 109.4 132.4 121.9 -- 142.9 124.9 154.9 144.9 -- 105.7 94.6 110 -- -- 92 -- -- -- 81 125 -- -- -- -- -- 101 -- -- -- -- -- -- 94 -- 81 -- 109 -- 88 Pride 2206 (2X) DeKalb XL15 (2X) *+Super Crost 2350 (2X) DeKalb XL31 (2X) Hyland HL-2458 (2X) -- 25.0 25 102.6 89.3 25.1 25 129.3 112.7 25 25.3 142.3 136.7 25.4 -- -- 131.0 120.2 25.4 -- 108 120 134 -- -- 122.5 109.8 -- 24 24 -- 76 93 105 -- -- -- -- 120 151 -- -- -- -- 87 106 -- 32.6 33.6 17.3 14.9 19.4 23.2 32.6 33.4 10.6 12.2 20.6 -- 11.9 6.0 23.3 10.4 8.9 11.7 13.9 12.3 11.9 -- -- 5.8 10.8 20.4 22.1 10.7 14.2 16.2 15.9 -- 6.8 14.8 16 -- -- -- -- -- -- -- -- 14 -- -- -- 13 -- 13 21 -- -- -- -- 32.4. 27.0 21.4 8.7 7.7 6.7 19.3 -- 12.2 -- 10.5 9.1 14 18 9 8 -- -- 20.3 33.3 11.3 11.9 5.5 30.9 7.3 4.8 34.5 10.6 -- -- -- 12 -- -- -- -- -- -- -- -- -- -- -- -- 12 16 -- 12 17 12 22 7 6 -- -- 8 -- 10 -- -- -- -- -- ---- -- 12 -- -- 10 -- 12 -- 8 -- 13 -- -- -- -- -- 6 4 -- 12 -- 10 17 -- 8 7 -- -- (continued) Table 1 (continued) Hybrid (Brand-Variety) Asgrow RX2345 (2X) Dairyland DX1003 (2X) Dairyland DX1099 (2X) Voris V2441 (2X) *+Pioneer 3780 (2X) *+Blaney B507 (2X) P-A-G SX181 (2X) *+Migro HP23R (2X) *+Pride 4488 (2X) *+Blaney B606 (2X) Voris V2411 (2X) Super Croat 2396 (2X) *+Michigan 5922 (2X) *+ADI 323 C2X) *+ADI 197 (2X) DeKalb XL23 (2X) Super Croat 79028 (2X) ADI 306 (2X) *+Migro M-2018X (2X) Migro M-2022X (2X) *+Golden Harvest H-2500 (2X) Average Range 135 -- 25 29 -- -- -- -- 16 8 129 105 131 94 -- -- -- -- 79 ---- 111 148 105 -- -- 25.6 26 25.7 -- -- 25.9 26 -- 106.2 91.9 26.2 -- -- 26.3 26 131.0 109.8 126.4 120.7 -- 127.4 108.3 -- 141.2 132.2 % Stalk lodging % Stalk lodging % Stalk lodging % Stalk lodging % Moisture % Moisture % Moisture Bushels per acre Bushels per acre Bushels per acre Bushels per acre Bushels per acre Bushels per acre % Stalk lodging % Stalk lodging 3 Years 3 years 2 Years 2 Years 1980 3 yrs. 2 yrs. 1980 1980 2 Years 2 years 3 Years 3 Years 1980 1980 Not Irrig Not Irrig Irrig Irrig Irrig Not Irrig Irrig Not Irrig Irrig Not Irrig Irrig Not Irrig 27 23-- -- 9.7 -- -- -- -- -- -- 6 12 -- -- 12 -- -- -- -- 13 3 2 4 4 6 5 -- -- -- -- 7.0 -- -- 12.1 14.6 -- 1 2 -- -- 0.7 2.9 -- -- -- 14 -- 8.1 5.6 94 18.3 10.1 10 5 -- -- -- 14.5 12.9 9 9 -- -- -- 12.4 8.8 -- -- -- 29.1 28.1 -- 4 4 8.6 5.3 5 5 9 9 8 6 12.4 7.1 -- ---- -- 26 -- 26.5 143.9 130.1 26.8 -- -- 131.5 120.3 -- 27 -- 148.6 129.9 26.8 26.9 28 147.5 138.0 27.4 28 164.9 150.2 132.9 122.5 -- -- -- 27.7 -- 132.9 114.1 -- -- -- -- 27.7 -- 27.8 30 -- 167.8 156.5 -- 28.6 -- -- 138.6 127.8 --- 28.6 29 138.8 127.8 -- 35.2 38.8 -- 7.6 16.4 17.0 21 -- -- 12.4 9.7 109 7.5 7.2 -- 12.0 14.1 -- -- 23.1 25.1 -- -- 14.4. 11.2 147 5.8 1.5 152 9.0 9.3 -- -- -- -- -- 12 9 -- 1 5 132 140 153 97 106 118 110 96 103 110 -- -- 98 128 135.5 122.0 28.8 28 28.8 -- ---- 28.8 29.0 29 27 29.4 28 27 -- 30.8 -- -- -- 134.8 119.7 -- -- -- -- 124.0 117.3 -- -- -- 155.8 140.8 143 113 120.6 113.6 117 93 164.0 147.8 -- -- -- -- 156 134 -- 144 124 26 26 142 119 --- 92 4.1 7.9 -- 8 13 6.7 -- 24.9 26 21.1 to 30.8 23 to 30 24 21 to 29 125.8 114.2 73.7 to 167.8 65.1 to 156.5 121 92 to 153 93 66 to 119 133 92 to 156 95 71 to 111 15.3 14.9 0.7 to 35.2 1.5 to 38.8 13 1 to 27 11 1 to 23 9 3 to 17 8 2to 15 -- least significant difference 1.5 1.0 0.7 13.2 12.6 9 7 6 5 -- -- -- -- -- *Significantly better than average yield, irrigated, in 1980. +Significantly better than average yield, not irrigated, in 1980. empty table cell 1980 May 12 Planted November 11 Harvested Soil Type Montcalm-McBride sandy loams alfalfa Previous crop Population 20,700 Rows 30" 315-155-155 Fertilizer Irrigation 3 inches Soil Test: pH 6.9 Soil Test 528 (very high) P Soil Test 290 (high) K 1979 May 19 November 19 Montcalm-McBride sandy loams alfalfa 20,800 30" 231-80-80 6 inches 5.4 493 (very high) 336 (very high) 1978 May 3 November 9 Montcalm-McBrid e sandy loams corn 20,700 30" 197-60-60 8 inches 6.7 362 (very high) 188 (medium) Farm Cooperation: Theron Comden, Montcalm Experimental Farm, Lakeview County Extension director: James Crosby, Stanton Table 2. Average, highest and lowest yields for corn hybrids irrigated and not irrigated for 13 years, 1968-1980. Year No. of Hybrids Tested Average Irrigated Average Not Irrigated Highest Irrigated Highest Not Irrigated Lowest Irrigated Lowest Not Irrigated 1980 1979 1978 1977 1976 1975 1974 1973 1972 1971 1970 1969 1968 71 83 73 74 80 75 76 72 72 56 64 63 56 126 109 144 125 156 154 112 114 157 163 144 146 136 AVERAGE empty table cell 138 114 67 88 73 72 125 103 101 137 28 103 86 96 92 167 142 186 158 183 207 134 138 206 211 194 185 182 176 156 92 112 88 93 157 122 120 179 42 128 109 123 117 74 67 92 89 120 106 65 78 99 91 95 97 92 90 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 13 years. 1968-1980. Year 15,200 Irrigated 15,200 Not Irrigated 19,200 Irrigated 19,200 Not Irrigated 23,300 Irrigated 23,300 Not Irrigated 27,400 Irrigated 27,400 Not Irrigated 133 123 146 141 153 158 118 108 152 173 1980 1979 1978 1977 1976 1975 1974 1973 1972 1971 1970 1969 122 126 1968 144 AVERAGE 139 123 77 92 74 72 136 100 97 132 37 114 96 146 140 164 152 174 183 130 134 187 189 169 159 144 158 135 87 110 81 84 164 111 116 159 35 130 110 150 138 175 160 181 196 135 128 191 191 193 167 158 173 131 83 100 70 81 151 98 106 149 20 107 100 93 96 141 131 165 150 161 172 120 108 161 181 178 151 151 148 112 109 91 91 124 78 94 69 68 146 94 102 144 11 89 92 85 86 U.S.D.A., DRY BEAN FOOD VALUE, PROCESSING QUALITY AND YIELD POTENTIAL IMPROVEMENT PROGRAM USDA-SE-AR and Department of Crop and Soil Sciences G. L. Hosfield Department of Food Science & Human Nutrition M. A. Uebersax M. W. Adams, A. Ghaderi, and J. L. Taylor Department of Crop & Soil Sciences Graduate Research Assistant, Department of Crop & Soil Sciences N. Wassimi Graduate Research Assistant, Department of Crop & Soil Sciences J. A. Izquierdo Graduate Research Assistant, Department of Food Science & Human Nutrition G. N. Agbo Experimental Objectives TO 1: Develop new and improved genetic populations, breeding lines, and cultivars of vegetables that combine improved yield potentials with favored food quality factors, pest resistance, tolerance to environmental stresses, and adapted for mechanized culture, harvesting, and handling. TO 2: Develop new and improved cultural and management practices that increase vegetable yields, minimize production losses, improve seed and food-quality attributes, and conserve and use scarce resources efficiently. Experiments regarding TO 1 Tests 0700-M, 0900-M, and N-Fix-Screen were planted on June 13, 1980 in 4 row plots spaced 50.8cm apart. Row length was 4.9m. Stand count were taken on each plot prior to flowering and from 4m sections of the two center rows. Physiological maturity data were recorded for each plot. Test 0700-M was designed to evaluate the effect of stress on seed fill, nutritional components, and processing quality of dry bean germplasm. Another goal of this study was to evaluate the relationship between C-assimilate partitioning in common bean yield and yield stability. Six strains of beans were tested (Table 1) under a stress imposed by removing source (leaves) at a physiological period for each strain corresponding to late seed fill. Late seed fill was chosen in hopes that pod set would not be influenced by source manipulations. Stressed plants were compared with non-stressed plants in each plot for seed yield, components of yield, percentage protein and ash, and processing characteristics. An identical experiment was conducted at the Saginaw Valley Bean and Sugarbeet Research Farm. Data from the 2 locations will be compared. Test N-Fix-Screen is a continuing experiment with a major goal to invest­ igate the relationship of nitrogen fixation rate and phytohemagglutinin type to nutrient availability and nutritional quality of dry and cooked beans. Test 0900-M was planted to: (1) evaluate the interrelationships among seed coat color, tannin content, and the hard-to-cook phenomenon in food legumes and (2) initiate a genetic program to study the inheritance of these quality factors. This experiment consisted of 20 strains of dry beans differ­ ing in seed-coat color, seed characteristics and agronomic traits. These materials were evaluated for tannin and protein content, soaking characteristics, and percentage of hard seed. Results and Discussion Data for tests 0700-M and N-Fix-Screen are incomplete at this writing and, hence, are unavailable for publication in this report. The results of test 0700-M showed large differences among lines for the rate of water uptake (Table 2). In addition, interstrain differences were noted for the percentage of hard seed after 48 hours soaking time (Table 2). Bean strains fell into one of two soaking categories (data not shown). Strains with few hardshell beans after 48 hours soaking reached a water uptake plateau for soaking after 12 hours, but strains with a significant amount of hard beans after 48 hours soaking never reached their water uptake plateau. The percentage of hard seed among genotypes ranged from 0 to 56% with red and brown seeded strains apparently most affected. Protein content among strains ranged from 22.1% to 28.4% and soaked bean texture ranged from 408 Kg/l00g to 1,034 Kg/100g. Simple correlation coefficients (Table 3) show no associ­ ations between percentage protein and texture and percentage hard seed and texture. The results of this work suggests that the hard seed defect may be associated with seed-coat pigments and tannin levels. Texture, however, appears to be independent of seed-coat color and tannin level. Experiments regarding TO 2 None. Table 1. Test 0700-M an evaluation of the effect of leaf removal stress on seed fill, nutritional components and cooking quality in six strains of dry beans. Strain No. Pedigree 1 2 3 4 5 6 Nep-2 San Fernando 61618 15-R-148 Sanilac P766 Seed coat color White Black White Red White Brown Seed source+ Michigan State University Michigan State University Michigan State University University of Wisconsin Commercial CIAT + CIAT = International Center for Tropical Agriculture, Cali, Colombia, South America. Table 2. Percent water uptake at 20C and eight time intervals, percent hard seed, protein content, and soaked bean texture for 20 strains of dry beans. Strain V1 v2 V3 v4 v5 v6 V7 v8 V9 V10 V11 Seed Coat ColorSoaking Interval Soaking Interval Hrs Hrs 2 8 Water Uptake g Water Uptake g Soaking Interval Soaking Interval Soaking Interval Hrs Hrs Hrs 28 4 12 Water Uptake g Water Uptake g Water Uptake g Soaking Interval Hrs Soaking Interval 48 Hrs Water Uptake g 20 Water Uptake g After 48 Hrs. % Protein % Texture Kg/100g 55.8 34.4 10.3 8.5 53.8 86.3 3.3 39.5 22.9 9.7 3.0 4.7 2.3 3.4 4.2 30.2 23.6 55.3 40.8 1.4 3.3 Brown Beige Red Red Brown Dark Brown Red Brown Beige Mottle 22.9 Glossy Beige 4.4 27.1 Yellow 64.1 Red 48.0 30.8 17.2 9.8 57.3 46.1 104.1 132.0 65.2 71.9 20.0 11.9 72.3 101.7 5.0 60.6 20.6 67.0 134.3 75.4 100.3 35.2 29.1 93.8 110.8 15.7 81.5 36.0 88.9 135.3 88.5 110.8 54.3 70.0 103.4 111.2 45.7 86.3 41.5 93.2 139.2 104.4 115.3 96.3 110.6 111.6 111.2 94.6 97.2 50.8 112.0 141.5 16.4 3.6 24.2 5.9 13.0 0.0 24.6 22.5 56.4 7.8 1.1 26.5 22.1 28.4 26.2 27.0 26.4 27.8 26.1 22.3 25.2 25.5 870 510 972 993 510 680 870 986 1,034 483 537 Table 2 Continued V12 V13 V14 V15 V16 V17 V18 V19 V20 Brown Beige Dark Brown Red Yellow Dark Brown Black White Beige 24.1 0.8 2.3 2.4 10.5 1.6 4.6 73.2 13.8 64.2 98.4 25.2 5.0 3.1 3.8 6.8 3.9 34.0 15.5 13.0 4.1 27.9 65.7 105.9 114.0 40.1 25.5 112.5 65.3 12.7 11.6 48.7 34.6 86.8 114.0 49.2 118.9 100.7 49.8 33.4 78.8 96.1 106.8 114.0 83.4 122.6 111.1 79.2 68.8 88.7 103.3 112.3 114.0 98.0 123.0 115.0 105.0 112.5 102.2 105.7 116.0 114.0 106.6 0.0 0.0 3.8 10.3 12.3 0.0 0.0 0.0 7.7 25.8 23.0 25.8 28.3 24.5 23.7 25.0 27.9 25.0 462 510 619 456 408 564 605 665 537 Table 3. Simple correlations among protein content, texture, and percentage hard seed in 20 strains of dry beans. Correlation Protein vs Texture Hard Seed vs Protein Hard Seed vs Texture Correlation coefficient (r) 0.196 0.050 0.293 DRY BEAN VARIETAL TESTING - COLORED BEANS M.W. Adams & J.L. Taylor Introduction Three sets of material were grown in 1980. One set consisted of Kidneys, cranberries, and large whites (14 entries), a second set consisted of 16 selections of light red kidney beans obtained from A. Andersen, and a third set consisted of 18 entries of cranberry selections tracing to A. Andersen (12) and M. Stilwell (6). Only the first test was grown in 4-row, 4 replicate plots. The spacing throughout was 18 inches between rows, plots were* irrigated whenever necessary, and neither insects nor diseases were a problem at this site. Average yields reflect the excellence of the growing conditions. Table 1. Yield (lbs/A at 16% Moisture) of Red Kidney, Cranberry, and Selected Large White-Seeded Strains at Comden Farm, Montcalm Co., 1980. Entry Type Date of Physiological Maturity Yield (lbs/A) Charlevoix Montcalm Manitou Mecosta 70684 70700 70688 Redkloud Sacremento Alubia 5408 61144 Michicran Cran 028 DRK DRK LRK LRK LRK LRK LRK LRK LRK White White White Cranberry Cranberry LSD.05 = 204 lbs/A 9/12 9/15 9/20 9/20 9/5 9/5 9/5 9/5 9/3 9/30 9/12 9/8 9/18 9/16 3297.4 2867.1 3090.2 2456.0 2833.2 3203.8 3443.9 3233.8 3592.7 2372.5 3340.8 3717.9 3219.4 3558.7 Table 2. Yield (lbs/A at 16% Moisture) Selected Light Red Kidney Strains Received from A. Andersen (grown only in two replications), Comden Farm, Montcalm Co., 1980. Test 0217a. Entry 9470 9473 9475 9476 9480 9478 9484 9485 9449 9482 9460 Date of Physiological Maturity Yield (lbs/A) 9/5 9/5 9/5 9/5 9/5 9/5 9/5 9/5 9/5 9/20 9/5 3098.1 3064.1 3061.5 3293.8 3609.6 3171.2 3609.6 3202.5 2805.8 2962.4 3098.1 Table 2, continued 9451 9453 9466 9465 9461 LSD.05 = 204 lbs/A Discussion 9/5 9/5 9/5 9/8 9/5 3045.9 3056.3 3244.2 3351.2 2899.7 Test 0217: It appeared from the performance of the limited number of late varieties included in this test that lateness was associated with somewhat lower yields. We have no explanation of this. Sacremento, which is the earliest entry in the test, was the second highest yielding strain tested. Alubia, the large seeded white bean from Argentina, did not mature under the conditions of this test and consequently yielded poorly. Two other large whites, which we have been testing, #5408 and #61144, yielded particularly well. They have also performed well in previous trials. The early maturing light red kidney strain, 70688, also performed well, and is being proposed for release as a new halo-blight tolerant variety for Michigan. Cran 028, a bush type, performed well in comparison with Michicran. Bean Shippers tell us, however, that the seed size of Cran 028 is slightly smaller than Italian type with which it must compete in marketing, thus no further steps are to be taken to release Cran 028. We have instead begun a crossing program to increase its seed size. Test 0217a: This test was grown adjacent to Test 0217 and we think the yields should be comparable. It consisted exclusively of entries submitted by Dr. A. Andersen, who stated that these entries derived from single plant selections which he had made within the variety Redkloud. Most of them resemble Redkloud indistinguishably in plant appearance, maturity, and yield. Two entries, 9480 and 9484, with yields of 36 cwt each, significantly out-performed Redkloud. We cannot be sure until further testing whether this margin of superior yield will be maintained. One entry, 9482, was much later than all the rest, as late as Manitou and Mecosta, with a yield similar to Manitou. It is surprising that such a late line would have originated in an early variety like Redkloud, and one must suspect that it is the result of a mixture or outcross to a later type. Other materials: In addition to the kidney tests noted above, we grew 18 entries of cranberry type beans, 12 of which came from Andersen and 6 from Mr. Martin Stillwell of the Heinz Company in England. Only short non-replicated rows of each were grown. All entries were bush type, with date of maturity ranging from 9/5 to 9/19. We have found nothing of immediate value as a variety, but possibly one of the Heinz selections may have merit in contributing larger seed size to a cross with Cran 028. MSU is an Affirmative Action/Equal Opportunity Institution