1973 Research Report MONTCALM EXPERIMENTAL FARM Michigan State University Agricultural Experiment Station ACKNOWLEDGEMENTS Research personnel working at the Montcalm Experimental Farm have received much assistance in various ways. A special thanks is made to each of these individuals, private com­ panies and government agencies who have made this research possible. Many valuable contributions in the way of fertilizers, chemicals, seeds, equipment, technical assistance and personal services as well as monetary grants were received and are here­ by 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 A. POTATO STUDIES Potato Breeding N. R. Thompson........................................................................................................................ 4 New Variety Evaluations R. W. Chase, N. R. Thompson, R. B. Kitchen...................................... 5 Planting Dates, Harvest Dates, Storage and Production Performance of Russet Burbank Seed Potatoes R. W. Chase and R. B. Kitchen...................................................................................... 13 Soil Fertility Research with Potatoes M. L. Vitosh and R. J. Kunze...................................................................................... 16 Potato Insect Research - 1973 A. L. Wells.................................................................................................................................. 22 Weed Control Evaluations in Potatoes on Mineral Soils J. S. Ladlie, W. F. Meggitt, R. C. Bond.............................................................. 32 1973 Potato Vine Killing Demonstrations R. W. Chase, W. F. Meggitt and R. C. Bond . . ............................................ 34 Effects of Late Spring Fumigation on the Stand and Yield of Five Potato Varieties E. C. Bernard ........................................................................................................................ 35 B. OTHER CROPS 1973 Grain Sorghum Hybrid Trial S. Hildebrand...................................................................................... 37 Bean Breeding Project M. W. Adams, A. W. Saettler and J. Taylor.......................................................... 38 Evaluation of Pickling Cucumbers Planted with Stanhay and Dahlman Seeders J. E. Motes.................................................................................................................................. 40 Corn Hybrids, Plant Population and Irrigation E. C. Rossman and Bary Darling.................................................................................. 42 MONTCALM BRANCH EXPERIMENT STATION RESEARCH REPORT R. W. Chase, Coordinator Department of Crop and Soil Sciences INTRODUCTION The Montcalm Experiment Station was established in 1966 with the first experiments initiated in 1967. This report marks the completion of seven 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 original 80 acre facility was reduced to 40 acres in 1973 primarily for budgetary reasons. 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 data obtained at the facility during 1973- Much of the data herein reported represents ongoing projects so complete 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 Temperature and rainfall recordings for the 1973 growing season are shown in Figure 1. Tables 1 and 2 summarize the 5 year rainfall and temperature data. Average maximum and minimum temperatures for 1973 were very near the 5 year average with some deviations in May and June. In the months of June, July, August and September, however, it was appreciably warmer than in 1972, while May was much cooler. An extended hot period occurred between August 26 and September 5 when there were three days of 90° and the average minimum temperature was never lower than 64°. This period undoubtedly had some effect on reducing the maximum potential yields. The total rainfall for the 6 month period was very near the 5 year average. Within the 5 year period there have been marked differences between monthly and 6 month totals. Most notable as being significantly below the 5 year average was the 1971 total whereas the 1970 totals were significantly higher. Rainfall in April, May and June of 1973 were all above the 5 year average and did contribute to less effective weed control. September, however was substantially below the 5 year level. This in part accounts for the excellent September and fall that we had for plot harvest. Irrigation applications of 1 inch each were made 7 times (July 10, 13, 20, 24, August 17, 28 and September 5). empty table cell APRIL MAY AVERAGE MONTHLY TEMP. MAX.54 MIN. 36 MAX.80 MIN. 60 RAINFALL 3.25 inches 3.91 inches 4.34 inches 2.36 inches 3.94 inches Figure 1. Climatology Observations at the Montcalm Experimental Farm in 1973. MAX.79 MIN.60 MAX. 63 MIN. 42 MAX.73 MIN.48 1.33 inches JULY AUGUST SEPT. JUNE MAX.77 MIN. 58 TABLE 1. The 5 year summary of recorded, maximum and minimum terperatures during the growing season at the Montcalm Experimental Station. April May May June June July July August August September September 6 month 6 month Min Max Min Max Min Max Min Max Min Max Min Average Average Year 1969 1970 1971 1972 1973 April Max 56 54 53 47 54 35 35 31 30 36 5 Yr. Ave. 53 33 67 65 65 70 63 66 43 47 39 47 42 44 70 72 81 72 77 74 50 55 56 50 58 54 80 80 82 79 79 80 59 60 55 57 60 58 82 80 80 76 80 80 56 57 53 57 60 57 73 70 73 69 73 72 49 51 54 49 48 50 74 73 76 73 74 49 45 48 48 51 empty table cell empty table cell TABLE 2. The 5 year summary of precipitation recorded during the growing season at the Montcalm Experimental Station (inches per month). Total Year April August May 1969 1970 1971 1972 1973 3.33 2.42 1.59 1.35 3.25 3.65 4.09 0.93 1.96 3.91 June 6.18 4.62 1.50 2.51 4.34 July 2.63 3.67 1.22 3.83 2.36 September 0.58 7.18 4.00 2.60 1.33 18.16 28.52 11.91 19.53 19.13 1.79 6.54 2.67 7.28 3.94 2.91 3.83 2.39 5 Yr. Ave. Soil Tests For specific projects where more detailed analysis are needed, the results are reported with the individual reports. Soil test results for the general plot area are: 19.45 2.74 3.14 4.44 Pounds/Acre Pounds/Acre Pounds/Acre P Pound/Acre pH 6.0 453 K 341 Ca 869 Pounds/Acre Mg 139 Fertilizers used Except for specific fertility studies where the fertilizers used are specified in the report, the following fertilizers were used on the potato plot area: plow down with rye banded with planter sidedress 0-0-60 200 lbs/A 20-10-10 600 lbs/A 33 1/3-0-0 420 lbs/A Disease and Insect Control A granular systemic insecticide (phorate or disulfoton) was applied to most of the potato plots at planting time at 3 pounds per acre. A second application of Disulfoton at 3 lb/A was applied to the late maturing varieties. The foliar insecticide program began on June 29 and continued on a weekly schedule until terminated on September 5. All spray applications were made with an air blast sprayer. The foliar insecticides used were Endosulfan (Thiodan), Meta-Systox-R, and Monitor. The fungicide used was Dithane M-45. Linuron (Lorox) at 1 3/4 lb/A applied preemergence was used for weed control. The fungicides used were Dithene M-45, Bravo and KoKocide 101. Dinitro at 2 qt/A plus a crop oil concentrate (Herbimax) at 1 qt/A was used as the topkiller. POTATO BREEDING N. R. Thompson Department of Crop and Soil Sciences One hundred seeds from each of 40 hybridizations were grown in the greenhouse. Two tubers from each plant were saved to grow in the field to determine which seed lots produced the most desirable cultivars. Ten thousand new cultivars were grown in East Lansing. Those meeting varietal requirements were saved for planting in 1974. These will be divided and planted in 2 locations - one in East Lansing for seed and one at the Montcalm Experimental Farm. The major emphasis for the year was seed production. Advanced cultivars were either greenhouse or Alabama tested. For the Alabama test, tubers were numbered and halved. One half was grown in Alabama and the half of all that passed the Alabama test were planted in East Lansing. Seed lots were harvested by hills within clones for 1974 plantings. Seed of MS709 harvested this way will plant 2 to 2 1/2 acres in 1974. Approximately 1000 hills of MS711-8, MS503-14 and Iallll-2 are also available. NEW VARIETY EVALUATIONS R. W. Chase, N. R. Thompson and R. Kitchen Department of Crop and Soil Sciences Seventeen varieties of potatoes were tested for adaptation to Michigan. Overstate variety plots were conducted at six locations: Henry and Andy Leep, Allegan County; Donald and Jerry Meyer, Bay County; Oscar Overholt, Emmet County; Montcalm Experimental Farm; Leon and Tony Delekta, Presque Isle County; and Joe Hassle, Van Buren County. These locations provided a range of climatic, soil and management con­ ditions which promotes the expression of their potential - good and bad alike. Variety test results should be considered on their relative performance. In other words, how a variety responds at each location, or when locations are summarized, in comparison with a standard or known variety is perhaps more valuable than the fact of whether it produced 300 cwt or 400 cwt/acre. The summary of planting dates and harvest dates is as follows: County Location Planting Date Harvest Date Days Allegan Bay Emmet MEF Presque Isle Van Buren May 9 May 8 May 19 May 10 May 15 May 7 September 27 August 31 September 25 September 20 September 11 September 7 141 115 129 133 119 123 Plant spacings were 12 inches. Chip samples were processed and scored on October 30-November 13. Table 1 summarizes the results of all the locations and Table 2 summarizes the yield and specific gravity data for each of the locations. There is a very definite variation in yield performance between locations with the Allegan and Van Buren locations producing the highest yields and the Bay and Emmet locations producing the lowest. The role of the fertilization factor is uncertain but there was a very definite weather influence between trials. In Bay County heavy rains occurred at planting and in the early growing season. In Emmet County there was an extended period of hot, dry weather in July and August which no doubt reduced yield potentials. And, in Presque Isle County excessive rains occurred par­ ticularly in July but also later in the season which probably accounts for the much lower specific gravity readings. Culinary qualities were also evaluated to determine after cooking darkening. Tubers from each variety and two locations, Allegan and Montcalm Experimental Farm were cooked by steaming for approximately 35 minutes. Ratings as to the degree of after cooking darkening were made immediately after cooking, at 1 hour and at 24 hours after cooking. After the samples were rated at 1 hour they were stored in a refrigerator and again rated at 24 hours. Ratings are based on a 1-5 scale with a 1 representing no flesh discoloration and a 5 being completely darkened. Table 3 summarizes these data. Additional samples have been stored at 40° and will be scored after storage in March. Table 1. The average yield, size distribution, maturity and quality of several potato varieties grown at six locations. Variety Hudson Katahdin MS-709 Onaway MS-503 Abnaki ND7196-18 Rushmore Superior Jewel Targhee Hi Plains Norchip ND6925-13 MS-1111-2 Nampa York Total Yield (Cwt/A) Marketable Yield (Cwt/A) Percent Size Distribution 7/8-3 1/4" Distribution +3 1/4" -1 Percent Size -1 7/8" Percent Size Distribution Specific Gravity Chip 1 Rating Maturi- ty2 Class 480 478 459 431 435 410 414 372 377 373 378 343 346 342 310 316 246 457 450 437 408 404 386 362 356 353 335 331 314 302 286 282 276 209 5.7 6.9 5.5 5.8 7.8 6.7 16.0 5.1 7.2 12.0 14.9 10.3 14.5 18.9 9.5 14.8 16.0 22.4 18.8 26.5 27.9 12.6 17.6 4.9 18.5 16.0 11.4 11.3 8.3 7.2 4.1 11.1 9.2 5.4 71.9 74.3 68.0 66.3 79.6 75.7 79.1 76.4 76.8 76.6 73.8 81.4 78.3 77.0 79.4 76.0 78.6 1.074 1.075 1.071 1.065 1.078 1.070 1.071 1.067 1.074 1.082 1.081 1.072 1.077 1.073 1.065 1.082 1.075 4.9 3.5 4.5 7.1 3.5 4.3 2.6 3.3 3.1 2.8 6.8 2.3 3.0 5.2 4.2 4.8 2.4 3.5 3 3 2 3 3 3 1.5 2 3 4 3 2.5 3 2 4.5 1 1 Based on a color reference standard of 1-10 prepared by the Potato Chip Institute International. The higher the number the darker the chip and the less acceptable. Generally a rating of 2-4 is most desirable for the Michigan area. 2 Based on a scale of 1-5. A 1 is the earliest maturity similar to the Irish Cobbler. Table 2. The marketable yield and specific gravity of several potato varieties grown at each of 6 locations. empty table cell Allegan MEF Bay BayS.G. Cwt/A Emmet Allegan Emme t S.G. S.G. Cwt/A 1.068 256 (7) 1.073 293 (3) 1.091 303 (1) 1.089 303 (2) 1.075 1.075 290 (4) 1.077 279 (6) 1.072 1.065 245 (5) 1.069 312 (1) 1.066 1.063 296 (2) 1.082 282 (4) 1.075 1.079 228 (8) 1.075 1.066 293 (3) 1.071 218(12) 1.073 136(15) 1.075 1.069 1.060 281 (5) 1.073 229(10) 1.075 1.068 242 (9) 1.085 1.079 1.076 156(17) 1.073 1.070 212(13) 1.077 245 (8) 1.082 1.073 1.070 209(14) 1.076 228(11) 1.067 1.062 1.072 158(16) 1.083 1.064 168(15) 1.078 Presque Isle Cwt/A Cwt/A MEFS.G. 376 (8) 484 (1) 1.077 420 (3) 432 (3) 1.079 426 (2) 460 (2) 1.078 396 (4) 1.068 381 (7) 378 (5) 1.083 393 (6) 298(12) 1.077 407 (5) 342(11) 379 (4) 1.077 332(12) 214(11) 1.073 359 (8) 1.070 412 (4) 276(14) 1.078 228 (7) 1.082 365 (7) 1.091 441 (1) 158(12) 1.088 329(10) 1.089 236 (6) 1.095 250(15) 359(10) 154(14) 1.073 335 (9) 1.078 251(16) 1.085 368 (9) 156(13) 1.078 122(17) 1.082 295(14) 293(13) 1.077 312(11) 1.069 225 (9) 1.068 312(13) 218(10) 1.097 254(15) 1.087 197(17) 131(16) 1.082 197(17) 1.081 212(16) Van Buren en Isle Van Bur Presque S.G. S.G. Cwt/A 1.073 1.064 694 (1) 1.061 1.073 515 (6) 558 (4) 1.072 1.062 1.057 576 (3) 1.069 1.070 482 (7) 1.076 1.071 1.061 529 (5) 580 (2) 1.071 1.061 1.060 1.067 435(11) 1.069 474 (8) 1.073 1.068 410(14) 1.079 1.070 463(10) 1.083 443(12) 1.071 1.062 1.069 — —— 1.071 1.064 1.060 — — 1.068 1.070 421(13) 251(15) 1.086 1.073 471 (9) Cwt/A 643 (2) 727 (1) 613 (3) 541 (7) 597 (4) 562 (5) 521 (8) 515 (9) 504(10) 398(13) 557 (6) 382(14) 490(11) 326(16) 335(15) 413(12) 300(17) Hudson Katahdin MS-709 Onaway MS-503 Abnaki ND7196-18 Rushmore Superior Jewel Targhee Hi Plains Norchip ND6925-13 MS-1111-2 Nampa York Location Average 495 1.069 239 1.075 213 1.081 341 1.079 348 1.064 486 1.074 ( ) The rank by yield of each variety. Variety observations Hudson is a new variety released by New York, in 1973. It possesses resistance to golden nematode and is projected as replacing Katahdin acreage on Long Island. It does have a high yield potential, however, its tendency to roughness may be greater than Katahdin. Based on these results it seemed to be slightly later than Katahdin and its specific gravity and chip ability were less. Considerable pink eye and off-type were noted at the Bay County location. It is worthy of further study. Katahdin used as a standard late variety for comparisons. It performed well at all locations. MS-709 - a Michigan seedling which continues to have a high yield potential. Its maturity is similar to a Katahdin with a lower specific gravity. Onaway - included as a standard early variety. MS-503- this Michigan seedling performed exceptionally well this year compared to earlier tests. Its maturity is similar to 709, however, its specific gravity and chip ability appear to be better. It rated the best in terms of absence of any after cooking darkening. Abnaki - a 1970 release by the U.S.D.A., New York and Maine, it has demonstrated an above average yield potential. Its gravity is low and it is not a good chipping variety. Although not always observed in our trials, some growers have reported of commercial plantings where hollow heart was serious. Table 3. The ratings* of several potato varieties for after cooking darkening at 0, 1 and 24 hours after cooking. Empty table cell After cooking Allegan Afte rcooking MEF 1 Hour Allegan 1 Hour____ 24 Hours 24 Hours MEF Allegan Hudson* Katahdin* MS-709* Onaway MS-503* Abnaki* ND7196-18 Rushmore Superior Jewel** Targhee Hi Plains Norchip ND6925-13 MS 1111-2 Nampa York 2 2 1 2 1 2 1 1 2 2 2 2 2 1 2 2 1 1 1 2 2 2 2 1 2 2 2 1 2 2 2 1 2 2 2 2 1 2 1 2 2 2 2 2 3 3 3 3 3 2 3 2 2 2 3 1 2 3 2 3 1 2 2 2 2 2 2 3 2 2 1 4 1 2 2 2 3 2 5 3 4 3 3 4 4 MEF Average 2.0 2.0 1.5 2.7 1.2 1.8 2.3 2.2 2.5 2 2 2 3 2 2 4 4 3 1 1.5 4 2 2 3 3 2 4 3.0 2.3 2.5 2.2 2.5 2.2 2.8 *Ratings based on a 1-5 scale with a 1 representing no discoloration and a 5 being completely darkened. ND 7196-18 - a round white North Dakota seedling which is reported to be ready for release in 1974. It is more long oblong in shape than is the Norchip and is reported to set a large number of tubers. This is evidenced by the high percentage of B size tubers and the low percentage of tubers over 3 1/4 inch. The specific gravity appears lower than Norchip. Rushmore - an older variety released in 1956 by Louisiana. It is an early maturing long russet type with low specific gravity. It was included in the 1973 trials for consideration as a variety for the early frozen processing market. Superior - included as a standard comparison variety. Jewel - relative yields in 1973 were lower than previous years. It does have a high yield potential, high specific gravity and is an excellent chipping variety. Some pitted scab noted at Bay County location. Targhee - a new release from Idaho in 1973. It is a long russet type variety, later maturity than a Katahdin and a high specific gravity. It does have Norgold Russet in its pedigree. In the two years of tests the Targhee has shown more promise than the Nampa. It is a late variety as evidenced by the difference in yields between locations and it did not produce an acceptable chip. It had a high percentage of B size tubers which perhaps relates to its lateness in maturity, particularly at the trials harvested earlier. This variety rated the poorest in terms of after cooking darkening. Hi Plains - is a 1965 release from Nebraska. It was included in our 1967 and 1968 trials where it was above average in yields. It is a long tuber with a white to slightly russetted skin. Its maturity is similar to Katahdin and medium to low in specific gravity. Norchip - included as a comparison variety. Yields in nearly all locations were below average. Poor stands and vigor were noted in some plots. ND6925-13 - an unreleased North Dakota round russet. Yields were very low and the percentage of B size tubers was the greatest of those tested. It does set a large number of tubers which did not ade­ quately size. It is medium to medium low in specific gravity and was undesirable as a chipping potato. MS 1111-2 - a Michigan seedling which matures early, however, yields and specific gravity are well below average. Nampa - released by Idaho in 1973 at same time as Targhee. It too has the Norgold Russet in its pedigree. Its performance in the two years of Michigan trials has been undesirable. Specific gravity readings are high, however, it is a late maturing potato, tuber shape was variable with more of a tendency to off-type than the Targhee. York - a Canadian variety which has been in our trials 3 years. It has a very early maturity, earlier than Onaway, however, yields are well below average. It does not appear to be well suited to Michigan conditions. PLANTING DATES, HARVEST DATES, STORAGE AND PRODUCTION PERFORMANCE OF RUSSET BURBANK SEED POTATOES R. W. Chase and R. B. Kitchen Department of Crop and Soil Sciences Procedure Foundation Russet Burbank seed was planted on May 9, 18 and 31, 1972 and harvested on August 15, September 1 and 15 and October 1 in 1972. Yield, grade and quality data were collected and 2 bushel samples were collected from each treatment for storage. Before placing in terminal storage, the samples were stored for 2 weeks at 60-65 F and 80-85% relative humidity to allow for proper curing. At the end of this time 1 bushel sample of each of the 12 treatments was stored at 40 F and the second at 34 F. Two weeks before planting in 1973, the seed was removed and warmed at 50-55 F. Except for the 1 treatment of the May 31 planting and August 15 harvest where tubers did not size, all plantings were made from 1 seed piece cut from each tuber in the sample. The balance of the tuber was discarded, therefore, each plant represented a different tuber. The seed was planted on May 11, 1973 in 1 row plots 25 feet long in 6 replications. Data on emergence, plant stand, vigor, yield and quality were obtained. Results and Discussion Table 1 summarizes the total yield and percent size distribution for the seed harvested at 4 different planting dates and stored at 2 temperatures. There is a general decline in yield from the later harvested seed. The greatest reduction in yield occurred between the September 15 and October 1 harvests. In terms of percent size distribution, there was no appreciable difference between any of the harvest dates. Table 2 summarizes the data for the 3 planting dates. Seed from the latest planted potatoes produced the lowest yields the following year. In terms of percent size distribution there was no effect, nor was there any effect related to storage temperature. Table 3 summarizes the effect of the 4 harvest dates for each of the planting dates. These data show that for each planting date the latest harvested seed resulted in the lowest yields when planted the following year. Similarily with the later plantings, the effect of a later harvest was more severe with the lowest yield resulting from seed planted late and harvested late. Storage temperature made no apparent difference on yield potential. Table 1. The total yield and size distribution of Russet Burbank potatoes grown from seed harvested at 4 different times and stored at 2 temperatures. Harvest Date* Total cwt/A Aug. 15 Sept. 1 Sept. 15 Oct. 1 344 333 307 265 empty table cell Seed Stored at 40 F Percent Size Distribution Seed Stored at 40 F Percent Size Distribution Seed Stored at 40 F Percent Size Distribution Seed Stored less than 1 7/8" 10.0 12.9 14.7 15.0 off type 7.7 9.2 12.3 12.1 over 10 oz. 15.0 13.6 14.5 15.6 at 40 F Percent Size Distribution 1 7/8"-10 oz. 67.3 64.3 58.5 57.3 empty table cellSeed Stored at 34 FSeed Stored at 34 F Seed Stored at 34 F Seed Stored at 34 F 363 349 319 257 Aug. 15 Sept. 1 Sept. 15 Oct. 1 *Harvest dates are for the seed grown the previous year. 63.3 66.3 62.8 58.5 17.7 13.1 16.5 15.1 11.2 13.8 13.4 16.0 7-8 6.8 7.3 10.4 Table 2. The total yield and size distribution of Russet Burbank potatoes grown from seed planted at 3 different times and stored at 2 temperatures. Planting Date* Total cwt/A Seed Stored at 40 F Percent Size Distribution Seed Stored at 40 F Percent Size Distribution less than1 7/8" May 9 330 320 May 18 May 31 287 empty table cell empty table cell 13.1 11.7 14.7 Seed Stored at 40 F Percent Size Distribution over 10 oz. 14.6 14.6 14.8 Seed Stored at 40 F Percent Size Distribution 1 7/8"-10 oz. 63.9 64.4 57.2 off type 8.4 9.3 13.3 Seed Stored at 34 F Seed Stored at 34 F Seed Stored at 34 F Seed Stored at 34 F 330 330 306 May 9 May 18 May 31 *Planting dates are for the seed grown the previous year. 12.8 13.6 14.4 7.0 7.1 10.2 64.4 63.2 60.5 15.8 16.1 14.9 Table 3. The effect: of planting dales, harvest dates, and storage temperature on the subsequent yields of Russet Burbank seed potatoes. Storage Temp. * * Storage Temp. Planting Date* May 9 May 9 May 9 May 9 May 18 May 18 May 18 May 18 May 31 May 31 May 31 May 31 May 31 Harvest Date* Aug. 15 Sept. 1 Sept. 15 Oct. 1 Aug. 15 Sept. 1 Sept. 15 Oct. 1 Aug. 15 Sept. 1 Sept. 15 Oct. 1 Average No. of Days Planting to Harvest 40 F (cwt/A) 34 F (cwt/A) 98 115 130 149 89 106 121 140 76 93 108 127 empty table cell 343 340 325 314 346 317 328 289 344 343 268 194 313 340 336 338 307 358 347 341 272 390 363 279 193 322 *Dates and storage temperatures are those for seed grown the previous year. The number of weak plants and ratings of plant vigor made early in the growing season were closely related to the subsequent yields. Vigor ratings of potatoes planted with seed harvested from the early and intermediate planting dates were about equal but were superior to that from seed planted late. The poorest vigor was observed in those plots planted from seed harvested on the October 1 date, regardless of the planting date. The number of weak plants was the greatest in the late planted seed and exceeded that of the early and intermediate planted seed by more than 60%. In part, the reduction in plant vigor, the high counts of weak plants and the reduced yields of potatoes planted from seed harvested late was due to late season virus infections of the plants before harvest. The highest counts occurred in the seed from the potatoes planted May 31 and harvested on October 1. This was 56% higher than the seed planted on May 9 and harvested October 1 and 70% higher than seed planted May 18 and harvested on October 1. Apparently the late planted and late harvested seed had a lusher foliage later in the season and was more attractive to aphids resulting in late season virus infection. These data are based on 1 year results of a 3 year study so interpre­ tations should be judged accordingly. It does suggest, however, that there could be real concern for the spread of late season virus infections on potatoes planted late, harvested late and having lush vine growth late in the season. SOIL FERTILITY RESEARCH WITH POTATOES M. L. Vitosh and R. J. Kunze Department of Crop and Soil Sciences Considerable change in Soil Fertility investigations at the Montcalm Experimental Farm has taken place since 1967 when the farm was first established. This past year the farm was reduced in size and as a result many of the soil fertility experiments were discontinued. In 1973 two soil fertility experiments were conducted. One was a liming study to evaluate its effect on potato yield, quality and the incidence of scab disease. This study was a follow-up of work done in 1972 where scab was more highly related to soil Mg levels than soil PH. Past research has also tended to indicate that Russet Burbanks yield better at PH 6.5 than 6.0. The other study was a N time of application study. Data in 1972 indicated that N applied through the irrigation system and spaced throughout the growing season tended to give larger potato yields than the conventional sidedress N treatment. The 1973 study was a follow-up of the experiment in 1972. Lime Study This experiment included 3 lime rates (0,2 and 4 tons/acre) and 2 liming materias (dolomitic agriculture limestone and dolomitic hydrated lime). The Dol-Ag lime had a neutralizing value of 106 compared to 166 for dolomitic hydrated lime. The actual amount of lime applied was adjusted so that each treatment contained an equivalent amount of lime based on a neutralizing value of 100 (pure calcium carbonate). This was done so that the 2 materials would neutralize approximately the same amount of acidity. If applied on a weight basis the hydrated material would have neutralized considerably more acidity. The soil PH on this site was 6.1. Normally this soil would not be limed where potatoes are the primary crop in the rotation; however, the intent of this study was to determine the effect of lime on incidence of scab disease, quality and the subsequent effects on yield. The results of the study are shown in Table 1. The cultural and management practices are listed at the bottom of the table. Potato tubers were sized into 3 categories (those greater than 3 1/4 inch, those less than 1 7/8 inch and those between 1 7/8 and 3 1/4 inch). Specific gravity was determined on tubers at East Lansing shortly after harvest. Ten tubers sampled at random from each plot were given a scab rating of 0 to 10. Those receiving a 0 rating had no evidence of scab. Those receiving a 10 rating would have had nearly the entire surface covered with scab or partially covered with deep pitted scab. The rating of 10 tubers were added together to give the value reported in percent. The 2 varieties, Kennebec and Katahdin were not significantly affected by any of the treatments. Scab ratings were very low with average ratings Table 1. Effect or rate and source of lime on yield, size and specific gravity or irrigated Kennebec and Katahdin potatoes. Lime Treatmentsa Kennebec Total Yield cwt/A Kennebec Kennebec less than 1 7/8"% Kennebec over 3 1/4"% 1 7/8" to 3 1/4" % Kennebec SP GR Scab Kennebec Rating % Katahdin Katahdin Katahdin Total Yield cwt/A Katahdin over 3 1/4"% 1 7/8" to 3 1/4" % less than 1 7/8"% SP Katahdin GR Scab Katahdin Rating % No Lime 2 Ton Dol-Ag Lime 4 Ton Dol-Ag Lime 2 Ton Hyd-Ag Lime 4 Ton Hyd-Ag Lime LSD (.05) 351 330 343 331 320 NS 13 12 12 12 10 NS 82 82 83 83 83 NS 5 5 5 5 6 1.070 1.071 1.070 1.070 1.072 7.5 7.5 6.2 9.5 7.5 NS NS NS 438 418 427 413 423 NS 11 16 13 11 13 NS 85 81 83 84 84 NS 3 4 4 4 4 1.073 1.072 1.073 1.072 1.072 6.2 4.5 6.8 2.8 5.2 NS NS NS aLime was applied on an equivalent basis using a neutralizing value of 100 for pure calcium carbonate. Planted: May 18, 1973 Row Spacing; 32 Inches Basic Fertilizer: 600 lbs. 20-10-10 at planting Seed Spacing: 10 Inches Irrigation: Harvested: September 27, 1973 Harvest Area: 266 sq. ft. Soil Tests: PH=6.1, P=330, K=346, Ca=841, Mg=128 5 Inches of less than 1 (less than 10% scab). These varieties were selected because of their susceptability to scab disease. Many growers are afraid to lime because they fear that liming may cause scab. This study does not substantiate their fears. The study will be continued to help growers develop a sound and profitable liming program. Yield and specific gravity likewise were uneffected by liming. Time of N Application Study Nitrogen fertilizer was applied to obtain 3 comparable treatments, all receiving the same amount but at various times of application throughout the growing season. All treatments received 84 lbs N/A as a starter fertilizer. The first treatment received 140 lbs N/A in one sidedress application on June 15. The second treatment received 70 lbs of sidedress N on June 15 and another 22 lbs N/A biweekly through the irrigation system for the next 6 weeks. The third treatment received 22 lbs N/A on a weekly schedule through the irrigation system over a 6 week period. Soil water samplers were positioned in each plot to monitor nitrate movement in the soil profile. Water samples were collected weekly or biweekly throughout the growing season. Soil samples were also collected at the same time as the water samples and at the same depth. Nitrate N was determined on both soil and water samples. Neither yield nor specific gravity were significantly affected by the N treatments (Table 2). The Kennebec variety, however, tended to yield better where N was applied in 6 applications through the irrigation system. The 2-year average would indicate that this method of application is a good method of applying N and will produce high quality yields. Both soil NO3-N and NO3-N in soil water samples were significantly correlated with the Kennebec yield (Table 3). No correlations were obtained for the Russet Burbank variety. Yields for this variety were essentially unaffected by the N treatments. Soil NO3-N in the surface foot was better related to Kennebec yields than soil NO3-N at the 2 foot depth. Soil water samples at the 2 foot depth were about as good as surface water samples in predicting potato yield. Nitrate-N levels in soil were in many cases significantly correlated with NO3-N levels in soil water samples, however, none were significantly related on the same sampling date at the same depth of sampling. The water samples contained much higher NO3-N concentrations than the soil. Average concentration of NO3-N in soil water samples were between 27 and 157 PPM while soil NO3-N concentrations were on the order of 3.1 to 10.1 (Table 4). Table 2. Effect of time of nitrogen application on yield, size and specific gravity of Kennebec and Russet Burbank potatoes. Nitrogena Applications Kennebec Kennebec Total Yield cwt/A over Kennebec 3 1/4"% 1 7/8" to 3 1/4" % less Kennebec than 1 7/8"% Kennebec SP GR Total Russet Burbank Yield cwt/A over Russet Burbank 10 oz% 1 7/8" to 10 oz % Russet Burbank Russet Burbank less than 1 7/8"% Russet Burbank Russet Burbank SP off GR type % 84PT, 140 ESD 84PT, 70ESD, 3*22 Irr. 84PT, 6*22 Irr. LSD (.05) 387 414 438 NS 12 13 12 NS 81 80 81 NS 8 7 7 NS 1.079 1.079 1.078 NS 360 364 357 NS 9 8 7 NS 78 75 78 NS 10 11 11 NS 3 6 4 1.071 1.073 1.071 NS NS aPT = planting time, 5-17-73, ESD = Early sidedress 6-15-73 3*22 Irr. - three biweekly applications of 22 lb N/A, 6*22 = six weekly applications of 22 lbs N/A through the irrigation system. Planted: May 17, 1973 Row Spacing: 34 Inches Basic Fertilizer: 600 lbs. 14-14-14 at planting Irrigation: 6.5 Inches Seed Spacing: 12 Inches Harvested: September 26, 1973 Harvest Area = 255 sq. ft. Table 3. Simple correlation coefficients for potato yields and nitrate nitrogen levels in soil and soil water samples taken throughout the growing season. aSoil and Water sample code: 1W8-30 NO^-N in soil water samples at 1 foot depth taken 8-30-73 2S7-11 NO^-N in soil samples at 1 foot depth taken 7-11-73 S6-28A Average NOyN in soil samples at 1 and 2 foot depth taken 6-28-73 Table 4. Nitrate-Nitrogen concentration of soil and soil water sampled throughout the growing season. Sampling Date Sampling Date Sampling Date 8-30 9-13 Soil Water Samples NO3-N 7-25 Sampling Date 8-15 Sampling Date 8-30 Sampling Date 9-13 Sampling Date Soil water Samples NO3-N Soil water Samples NO3-N Soil water Samples NO3-N Soil Water Samples NO3-N 9-20Soil water Samples NO Sampling Date 3-N N Application a Ibs/A Depth Ft. 84PT, 140 ESD 84PT, 140 ESD 84PT, 140 ESD 84PT, 140 ESD 0-1 1-2 2-3 Ave. Irr. 84PT, 70 ESD 3*22 0-1 84PT, 70 ESD 3*22 Irr. 1-2 84PT, 70 ESD 3*22 Irr. 2-3 384PT, 70 ESD 3*22 Irr. Ave. Irr. 84PT, 0ESD 6*22 0-1 84PT, 0ESD 6*22 Irr. 1-2 84PT, 0ESD 6*22 Irr. 2-3 84PT, 0ESD 6*22 Irr. Ave. 6-28 Soil Samples ppm Sampling Date Sampling Date 7-18 8-15 7-25 Sampling Date Sampling Date 7-11 Soil Samples ppm Soil Samples ppm Soil Samples ppm Soil Samples ppm 9.8 1.6 1.7 4.4 5.0 1.7 2.1 2.8 9.1 3.2 4.1 5.5 6.0 2.9 2.4 3.8 4.1 2.6 2.2 2.9 3.2 2.8 5.8 4.0 2.8 4.2 4.0 3.7 3.0 3.5 2.1 2.9 3.4 3.2 2.6 3.1 4.4 3.1 4.1 3.9 4.4 2.8 4.2 3.8 5.0 2.8 2.8 3.5 6.2 6.2 5.2 5.9 5.3 4.9 5.4 5.2 7.1 5.8 6.2 6.4 Soil Samples ppm 11.7 9.0 9.5 10.1 8.9 7.8 9.3 8.7 7.4 5.8 6.4 6.5 aSee footnote "a" table 2 for definition of N treatments. 10.3 8.7 7.8 8.9 6.6 5.7 8.4 6.9 7.6 6.1 7.0 6.9 282 49 130 154 74 58 28 54 90 26 44 53 70 47 85 67 22 58 24 35 25 28 29 27 27 51 73 50 26 79 22 42 21 44 28 31 14 20 71 35 34 69 58 54 24 46 28 33 17 30 59 35 27 56 22 35 22 47 24 31 POTATO INSECT RESEARCH — 1973 Arthur L. Wells Department of Entomology The 1973 entomological research on potatoes was planned to better understand insect populations and to study new materials and techniques for their control. The work at the Montcalm Farm consisted of 3 main projects: (1) Evaluation of soil systemic and foliar insecticides; (2) Comparison of single and double applications of Disyston on 5 varieties under irrigated and non-irrigated conditions; and (3) Comparison of seed and soil treatments of Orthene on potatoes. An additional study to evaluate foliar applications of insecticides was conducted at the Muck Experimental Farm. A. Montcalm Experimental Farm Evaluation of systemics Seventeen treatments were compared for insect control on Norchip and Burbank varieties. Three replications of paired 50-ft. rows of each variety were planted and treatments applied on May 15 and 16. Sidedress applications of Disyston were made on June 27 at time of hilling at which time the first foliar applications were made on certain plots. An additional foliar application was made on August 2 on these same plots. Leaf samples were taken periodically on both varieties to determine flea beetle, leafhopper and aphid populations. Foliar sampling of the plots were made with a sweep net (10 sweeps/replication) on July 31 and August 20. Yields and size gradings were made at harvest of the plots on September 24 and 26. The insect data and yields are presented in Tables 1 and 2 respectively. Disyston - Variety study Paired non-replicated plots of 5 commercial varieties of potatoes treated with single and double applications of Disyston were compared with untreated plots under irrigated and non-irrigated conditions. The purpose of the study was to determine if the movement of the insecticide was adequate in the non-irrigated plots to provide insect control and affect subsequent yields. The plots were sprayed on a commercial schedule to simulate grower use of the materials. Leaf samples were checked periodi­ cally to determine differences in insect populations and yields and quality were determined at harvest (Table 3). Orthene seed and soil treatments The purpose of this study was to determine the effects of Orthene on foliar insects when applied as dry seed treatments to cut seed. A granular formulation was applied in the seed row for comparison with the seed treatments. Leaf samples were taken periodically to determine effects on flea beetles and aphids. Yields and quality of the tubers were determined at harvest (Table 4). Table 1. Soil systemic evaluation on potatoes at Montcalm Farm Foliar insect control Dates of sampling: July 31 and August 20 (10 sweeps/each of 3 replications) empty table cell Thimet B Thimet B Foliars Disyston B Disyston B+S Disyston B+F Disyston B+S+F Disyston F DS 15647 2 DS 15647 3 Temik 10 Temik 15 Furadan 2 Furadan 3 CGA 12223 Monitor Untreated Untreated Potato Potato Leafhopper Leafhopper Aug. 20 July 31 Flea Beetle Flea Beetle Aug. 20 July 31 Tarn. Plant Bug July 31 Tarn. Plant Bug Aug. 20 Aphids July 31 Aphids Aug. 20 9 12 12 9 18 10 27 1 2 5 7 6 6 32 26 25 25 0 1 2 1 0 0 1 0 0 0 0 0 0 3 1 3 3 1 5 8 6 7 11 20 0 4 6 4 1 2 10 20 38 33 0 0 1 1 0 3 0 0 0 0 1 3 0 2 2 2 5 12 17 15 10 16 25 10 8 17 3 8 6 9 18 16 11 21 15 22 17 20 13 16 16 15 14 7 4 14 5 28 11 13 21 6 4 0 0 1 5 6 5 4 0 0 21 10 10 4 2 9 53 22 18 25 11 12 11 33 27 7 8 95 96 78 8 22 5 Colorado Potato Beetle July 31 A Colorado Potato Beetl eJuly 31 L Colorado Potato BeetleAug. 20 A Colorado Potato BeetleAug. 20 L 0 2 0 2 2 2 1 0 0 0 0 0 0 0 0 4 1 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 1 0 0 8 1 69 15 8 7 26 0 0 2 0 0 0 17 5 50 10 *For rates and placement refer to Table 2. Table 2. Soil systemic evaluation on potatoes. Yields, size distribution and specific gravity of tubers at harvest. Date planted: May 15 and 16; Date harvested: Norchip-Sept. 24, Burbank-Sept. 26. Foliars applied: June 27 and August 2, 1973. Material and Formulation Rate/A (Tox.)* Place­ ment** Norchip Yield/A Cwt. Norchip Yield/A Bu. Norchip % Size Distribution to 1-7/8 Norchip % Size Distribution 3-1/4"+ Spec. Norchip Gravity Burbank Yield/A Cwt. Burban k Yield/A Bu. Burbank % Size Distribution to 1-7/8" Norchip % Size Distribution 1-7/8-3 1/4" Burbank % Size Distribution 1-7/8-10 oz Burbank % Size Distribution 10 oz+ Thimet 15G Thimet 15G + (Thiodan 50WP + Cygon 267) Disyston 15G Disyston 15G + Disyston 15G Disyston 15G +Disyston 15G Disyston 15G + Disyston 15G + Monitor 4E Disyston 6SC D.S.-15647 10G D.S.-15647 10G Temik 10G Temik 15G Furadan 10G Furadan 10G CGA 12223 5G Monitor 4E Untreated Untreated 3 lb 3 lb 3/4+1/2 296 491 Band Band Foliar 249 413 279 463 280 465 3 lb Band 3 lb Band 3 lb Side 3 lb Band 1 lb Foliar 252 418 3 lb Band 3 lb Side 3/4 lb Foliar 280 465 1 lb Foliar 250 415 2 lb Band 279 463 3 lb Band 263 437 3 lb Band 326 541 3 lb Band 339 563 2 lb Band 314 521 3 lb 308 511 Band 3 lb Band 248 412 3/4 lb Foliar 270 448 — 274 455 — 280 465 — — 3 5 3 3 3 4 3 3 3 3 3 3 3 4 3 3 2 90 90 89 91 91 89 92 92 88 88 88 90 91 93 91 92 91 7 5 8 6 6 7 5 5 9 9 9 7 6 3 6 5 7 1.073 1.063 1.069 1.075 1.072 1.077 1.068 1.070 1.066 1.068 1.073 1.073 1.075 1.071 1.073 1.067 1.067 360 598 351 583 384 637 384 637 371 616 373 619 370 614 380 631 387 642 430 714 428 710 391 649 379 629 252 418 370 614 363 603 363 603 4% 4% 3% 3% 4% 4% 4% 4% 3% 4% 3% 4% 4% 6% 8% 8% 3% 83% 83% 80% 77% 79% 78% 82% 75% 82% 76% 75% 77% 78% 80% 80% 80% 77% *Granular treatments applied in 4 in. band in seed row (rates based on 34" rows (15,390 row ft/A) **Side dress application applied at time of hilling, June 27. Burbank Off type 5% Burbank Spec. Gravity 1.071 1.070 8% 8% 5% 9% 10% 10% 10% 8% 10% 9% 12% 13% 13% 11% 5% 4% 4% 12% 8% 1.077 10% 1.072 7% 1.074 8% 6% 11% 6% 8% 9% 6% 7% 9% 8% 8% 8% 1.077 1.078 1.076 1.079 1.076 1.078 1.076 1.074 1.072 1.068 1.074 1.074 Results The differences in insect control between any of the systemic plots when measured by leaf sampling were insignificant due to the low levels of infestations. The sweep samples indicated a trend in certain plots on late aphids and Colorado potato beetles. Definite differences in yields of the plots are noted on both varieties especially the Temik and Furadan treatments on the Norchips and Temik on the Burbanks. The most apparent differences in the yields of the varieties in the Disyston irrigation study were the effects of irrigation water during mid­ season since very few insects were present on any of the plots. The plots should have been replicated to determine if the variability of the yields between the treatment rates of the insecticide were significant or not. The phyto-toxic affects of the 1 and 2 ounce rates of the Orthene to the cut seed were apparent soon after emergence of the seedlings. These differences were soon masked by early growth and were not apparent later on. The Orthocide fungicide had a safening effect on the germinating seed since the effects did not show up in the combination treatments. There were very few insects in the plots as determined by leaf samples although they were not sprayed during the season. There were very few differences between the yields at harvest. Table 3. Soil Systemic Evaluation on Potatoes at Montcalm Farm. Varietal Response to Disyston Treatments under Irrigated and Non-irrigated Conditions. Date Planted: May 18. Date Harvested: Sept. 27, 1973. Size of Plots: Paired 50 ft. rows each with 50 seed pieces. Lbs. Disyston/A. Yield/A . Cwt Yield/A .Bu % Size Distribution to 1-7/8 % Size Distribution 1-7/8"-3-1/4" % Size Distribution3-1/4"+ % Size Distribution Off-type Specific Gravity 356 335 339 244 295 281 395 397 439 363 349 294 389 415 372 304 331 323 350 336 337 215 235 276 308 320 377 591 556 563 405 490 466 656 659 729 603 579 488 646 689 618 505 549 536 581 558 559 357 390 458 511 531 626 2% 2% 3% 6% 3% 5% 1% 1% 1% 2% 1% 2% 1% 2% 1% 2% 2% 2% 1% 1% 1% 4% 2% 4% 2% 2% 4% 5% 9% 8% 92% 96% 93% 91% 96% 93% 73% 78% 72% 83% 88% 80% 83% 87% 84% 84% 85% 76% 85% 92% 88% 92% 90% 89% 79% 78% 74% 80% 81% 82% 6% 2% 4% 3% 1% 2% 26% 21% 27% 15% 11% 18% 16% 11% 15% 14% 13% 22% 14% 7% 11% 4% 8% 7% 10 oz + 9% 12% 14% 1% 1% 1% — — — — — — — — — — — — — — — — — — — — — — — — 10% 8% 8% 14% 9% 9% 1.056 1.055 1.057 1.057 1.056 1.054 1.063 1.061 1.061 1.060 1.064 1.061 1.061 1.064 1.063 1.064 1.062 1.067 1.073 1.073 1.068 1.071 1.079 1.066 1.073 1.072 1.072 1.078 1.072 1.068 Variety Norland Irrigated NorlandIrrigated NorlandIrrigated 0 3 6 NorlandNon-irrigated 0 3 6 NorlandNon-irrigated NorlandNon-irrigated Onaway Irrigated OnawayIrrigated OnawayIrrigated 0 3 6 OnawayNon-irrigated 0 3 6 Onaway Non-irrigated Onaway Non-irrigated Sebago Irrigated Sebago Irrigated Sebago Irrigated 0 3 6 Sebago Non-irrigated 0 3 6 Sebago Non-irrigated Sebago Non-irrigated Norchip Irrigated Norchip Irrigated Norchip Irrigated 0 3 6 Norchip Non-irrigated 0 3 6 Norchip Non-irrigated Norchip Non-irrigated Russet Burbank Irrigated Russet Burbank Irrigated Russet Burbank Irrigated 0 3 6 Russet Burbank Non-irrigated0 273 285 236 392 Russet Burbank Non-irrigated Russet Burbank Non-irrigated 3 6 453 473 Table 4. Seed and Soil Treatments with Orthene for Potato Insect Control Type of applications: Seed treatments on cut seed or ganular band in row with seed. Size of plots: 3 replications of single 50 ft. rows (50 seed pieces/plot). Variety: Russet Burbank Date planted: May 21; Harvested: October 1, 1973 Material and Formulation Seed Treatments Rate of Appl. oz/cwt Rate of Appl. oz/cwt Tox. Form. Yield/A . cwt. Yield/A . Bu. % Size Distributionto 1 7/8" % Size Distribution 1 7/8-10 oz % Size Distribution 10 oz + % Size Distribution Off-type Specific Gravity Orthene 75S .67 oz 0.5 oz 1.33 oz Form. Orthene 75S Seed Treatments Tox. 1.0 oz Tox. 2.0 oz 2.67 oz Form. Orthene 75S Seed Treatments 3.36 oz Form. Orthene 15%-Orthocide 15% dust Tox. 0.5 oz Seed Treatments Form. 6.72 oz Orthene 15%-Orthocide 15% dust Tox. 1.0 oz Seed Treatments Orthene 15%-Orthocide 15% dust Tox. 2.0 oz Form. 13.28 oz Seed Treatments 8.00 oz Form. Orthocide 15% dust Seed Treatments Tox. 1.2 oz 293 290 269 299 287 290 282 486 481 447 496 476 481 468 Soil Treatments Orthene 5% Gran. Soil Treatments Orthene 5% Gran. Orthene 5% Gran. Soil Treatments Di-Syston 15% Gran. Soil Treatments Untreated Soil Treatments +Orthene 5% Gran.(sidedress)** 2 lb* 4 lb* 3 lb* 2 lb.* 3 lb.* — 40 lb* 80 lb* 60 lb* 40 lb.* 20 lb.* —— 293 286 294 486 475 488 306 270 508 444 7% 6 11 7 7 8 6 5 8 5 5 8 76% 78 79 73 76 74 79 74 72 74 72 70 4% 4 2 75 3 4 1 4 4 4 7 5 13 12 8 15 14 14 14 17 16 17 16 17 1.072 1.072 1.075 1.072 1.074 1.073 1.067 1.074 1.068 1.071 1.074 1.071 *Granular treatments applied in 4 in. band in seed furrow. Rates based on 34" rows (15,390 row ft./A) **Sidedressed at hilling (June 27, 1973) B. Muck Experimental Farm Foliar Insecticide Evaluation A project was initiated in May to evaluate 25 labeled or candidate materials for foliar insect control on potatoes. The plots using Sebago seed were laid out in 3 replications of paired 25 foot rows. Applications were made on August 3, 14, 22 and 30 using a hydraulic sprayer with drop nozzles and delivering 100 gallons per acres. (Note: The Thiodan treatment was included in the first 2 applications after it was replaced with the Pirimor treatment for evaluation on aphids). Foliar insect populations were evaluated at intervals during and after this period on the plots by sampling with a sweep net (10 sweeps/plot). The data for the potato flea beetle and green peach aphid populations during the study are presented in Table 5 and the totals for the other major potato insects are shown in Table 6. The plots were harvested on October 9 to determine yields and graded for size classification. These data are presented in Table 7. Results The seasonal fluctuation of flea beetle adults due to generation development is clearly shown in Table 5 by the high numbers in the samples in early August and again in early September. A sample from the untreated plot on July 26 prior to any treatments indicated 181 beetles/30 sweeps. The samples on August 3 were taken immediately after the first application and thus provide data on the knock down ability of the materials. The samples on August 10 compare their population effects after 1 week. The populations on the untreated plot remained comparatively low during and after this period due possibly to loss of vigor in the plants from leaf­ hopper feeding. The samples on September 7 again measure the residual effects 1 week after application. There are definite differences between the materials when compared in this manner. The aphididal effects of these treatments are also shown in the table. Although the populations were lower than in previous years, the seasonal development when not controlled, is obvious in several of the treatments. The residual or systemic effects are again measured by the population build-up 1 week after the last application (August 30 - September 7). There was practically no foliage left on the untreated plots at this time — thus the low aphid counts. The potato leafhopper populations were at their peak at the start of the foliar sampling and tapered off in August. The totals as shown in the table were predominately from the second sampling (August 10) seven days after the first application. The potato beetle population was much lower at the Muck Farm than it has been in recent years. There was considerable variation in yields between the replications of the treatments and even though there appear to be differences it is doubtful if they are highly significant from the untreated plot. The differences between treatments cannot be explained only from the insect population data. The quality of the tubers was excellent with good size resulting from all of the treatments. Table 5. Flea beetle and Aphid control from foliar treatments. Material * Bay Hox Bay Hox + Guthion Monitor DiSyston Orthene Lannate 90 Lannate L Vydate Vydate + Lannate CGA 18809 CGA 15324 Thiodan (Pirimor) R-30956-M MGK RV-111679 Furadan Zolone Azodrin Imidan Dyfonate N-2596 Phosvel Pen-Cap SN-334B UNI-K840 Cygon + Sevin Untreated Untreated Insects/30 SweepsPotato Flea Beetle 8/22 8/10 Insects/30 Sweeps Potato Flea Beetle 8/3 Insects/30 Sweeps Potato Flea Beetle Potato Flea Beetle Insects/30 SweepsPotato Flea Beetle 8/30 Insects/30 SweepsPotato Flea Beetle 8/31 35 11 11 8 6 3 7 17 7 5 3 5 62 18 0 6 2 16 7 7 7 13 9 24 15 53 67 66 91 72 81 55 63 57 124 67 61 84 64 80 56 20 40 62 46 54 31 32 60 63 80 104 53 40 5 6 5 7 9 5 1 19 3 5 5 3 5 2 19 3 6 5 2 1 3 10 4 5 6 2 3 17 26 10 15 6 1 9 32 13 8 13 6 5 3 4 6 4 7 5 6 2 9 7 10 13 13 16 6 1 1 0 6 1 0 4 0 2 0 5 1 2 10 1 1 7 0 0 3 2 3 4 1 11 20 9/7 126 82 36 44 69 52 29 134 258 18 76 152 38 113 5 18 36 34 16 55 16 48 62 100 26 47 91 *For rates and dates of application refer to Table 6. Potato Flea Beetle Insects/30 SweepsPotato Flea Beetle Insects/30 Sweeps Insects/30 SweepsGreen Peach Aphid Insects/30 SweepsGreen Peach Aphid totals 8/3 8/10 Insects/30 SweepsGreen Peach Aphid 8/22 Insects/30 SweepsGreen Peach Aphid 8/30 Insects/30 SweepsGreen Peach Aphid 8/31 9/7 Insects/30 Sweeps Insects/30 Sweeps Green Peach Aphid Green Peach Aphid totals 255 217 135 155 155 120 103 330 348 99 181 232 191 194 58 74 111 115 84 100 63 142 148 223 165 169 237 2 0 0 0 1 0 0 3 3 4 1 3 7 1 1 1 0 1 1 6 5 0 3 9 3 4 10 13 11 14 0 2 2 9 14 10 3 3 4 69 42 26 5 7 27 13 22 22 29 20 32 5 28 28 2 2 2 0 1 6 17 22 21 22 4 7 13 15 13 4 1 6 1 27 70 3 4 16 2 9 36 3 2 0 0 0 3 21 31 24 30 2 2 7 28 73 5 8 10 3 41 135 7 6 31 2 10 24 0 0 1 2 7 2 8 53 22 31 1 5 1 30 29 1 160 13 2 23 188 20 15 46 0 14 14 3 11 1 0 3 3 84 322 312 97 11 4 3 101 121 102 532 89 17 35 940 1318 149 37 2 26 52 23 26 18 2 14 16 139 445 392 157 22 25 100 217 263 118 708 146 37 154 1359 1377 197 171 14 91 164 Table 6. Foliar insect control with foliar applications of insecticides. Dates of application: August 3, 14, 22 and 30, 1973. Dates sampled: August 3, 10, 22, 30, 31 and September 7 (one week after last appl.) ) s p e e w s 0 3 / . o N ( ) s p e e w s 0 3 / . o N ( d e t c e l l o c s t c e s o n t I a l a t t o o T P d e t c e l l o c r e s t p c e p s o n r I h e l f a t a s t o e A * T l r e p p o h f a e l ) s p e e w s 0 3 / . o N ( d e t c e l l o c d s t e c e h s s n i I n l a r t a o T T ) s p e e w s 0 3 / . o N ( ) s p e e w s 0 3 / . o N ( ) e a v r a l d e t c e e l l l t o e c & e s t b o c e d s a n r I o l a l t o o C T s t l u d a ( o t a t o p d e t c e l l o s c e s s t t r i c s o e s a t n a r I * d a l a p * e t r o & T P g u b t n a l p Material & Formulation Bay Hox 4 EC Bay Hox 4 EC + Guthion 2SC Monitor 4 EC DiSyston 6 SC Orthene 75% S Lannate 90 WDP Lannate 1.8 L Vydate 2 L Vydate 2 L + Lannate 1.8 L CGA 18809 50 WP CGA 15324 500 ml./kl. EC Thiodan 50 WP Pirimor 50WP Stauf. R-30956 M MGK RV-11679 Furadan 4 F Zolone 3 EC Azodrin 3.2 EC Imidan 50 WP Dyfonate 4 EF Stauf. N-2596 4 F Phosvel 45 WP Penn-Cap 2 EC NorAm SN-334 B 97% UNI-K840 4 EC Cygon 267 + Sevin 80 S Untreated Untreated Rate (Tox.) per Acre 1/2 lb. 1/2 + 1/2 lb. 1 lb. 1 lb. 3/4 lb. 1/2 lb. 1/2 lb. 1/2 lb. 1/4 + 1/4 lb. 1 lb. 1 lb. 1 lb. 1/2 lb. 1 lb. 1 pt. 3/4 lb. 1 lb. 3/4 lb. 1 lb. 1 lb. 1 lb. 1 lb. 1/2 lb. 1 lb. 1/2 lb. 1/2 + 1 lb. — — 176 427* 169 132 114 117 142 165 213 201 208 158 704 318 162 200 90 133 199 160 217 120 172 291 224 622 945 88 63 44 104 50 51 81 86 68 85 118 110 78 90 62 38 90 86 34 78 91 71 92 60 48 107 122 213 130 67 82 87 92 80 113 78 86 111 107 4 145 154 97 83 87 131 91 127 143 119 80 83 62 357 404 9 1 3 4 3 54 4 1 2 0 2 0 5 1 1 1 0 0 0 2 4 4 12 4 11 14 11 18 10 4 8 11 18 12 22 8 12 7 15 20 26 15 30 14 11 31 31 25 19 25 14 28 32 *High populations on August 10, 7 days after application, were predominant contributor to these totals. **Ladybird beetles, lace wings, wasps and spiders. Table 7. Yields and size grades from potato foliar plots Yield/A Bu. Yield/A Cwt. 464 500 443 460 484 479 493 420 474 392 499 529 505 546 538 395 442 395 483 517 439 423 433 529 518 409 280 301 267 277 291 288 297 253 286 236 300 319 304 329 324 238 266 238 291 312 266 255 261 318 312 246 * Materials Bay Hox Bay Hox + Guthion Monitor DiSyston Orthene Lannate 90 Lannate L Vydate Vydate + Lannate CBA 18809 CBA 15324 Thiodan (Pirimor) R-30956-M MGK RV-111679 Furadan * Zolone Azodrin Imidan Dyfonate N-2596 Phosvel Pen-Cap SN-334B UNI-K840 Cygon + Sevin Untreated Less than PERCENT SIZE DISTRIBUTION 1-7/8" Greater than PERCENT SIZE DISTRIBUTION PERCENT SIZE DISTRIBUTION l-7/8"-3-l/4" 3-1/4" 6% 5% 6% 6% 5% 6% 6% 6% 6% 6% 6% 5% 5% 4% 5% 8% 6% 7% 7% 5% 6% 8% 5% 6% 7% 7% 70% 64% 69% 66% 68% 69% 63% 74% 71% 64% 64% 66% 61% 66% 60% 68% 67% 64% 65% 62% 67% 70% 63% 58% 66% 68% 24% 31% 25% 28% 27% 25% 31% 20% 23% 30% 30% 29% 34% 30% 35% 24% 27% 29% 28% 33% 27% 22% 32% 36% 27% 25% *For rates and dates of application refer to Table 5. WEED CONTROL EVALUATIONS IN POTATOES ON MINERAL SOILS James S. Ladlie, William F. Meggitt and Robert C. Bond Department of Crop and Soil Sciences Russet Burbank potatoes were planted on May 20 on a sandy clay loam with 2 to 3% organic matter, Montcalm County, Michigan. The plots were 10 X 50 ft. in a randomized complete block design with 3 replications. The preemergence treatments were applied May 31 and the postemergence treatments June 16. Treatments were applied with a tractor mounted sprayer delivering 23 gpa. Rainfall was 1.62 inches within 7 days after preemergence application and 1.10 inches 7 days after postemergence application. The soil surface temperature at the time of postemergence application was 80°F and the air temperature 82°F. The Russet Burbank potatoes were 4-6 inches with the broadleafs and grass being 3-4 inches at the time of postemergence application. The major weeds present were redroot pigweed, lambsquarter, barnyardgrass. The plots were visually rated on June 21. The preemergence and postemergence herbicide treatments all gave 93% or more control of the broadleaf weeds. The control of grass was 90% or more for all treatments with exception of these treatments: M & B 14255, 2 lb/A and S-6044, 2 lb/A preemergence; chlorbromuron, 2 lb/A postemergence. Preemergence treatments controlling 93-100% of both the broadleaf and grass species were metribuzin, 1/2 and 1 lb/A; alachlor + dinoseb 2+4 1/2 lb/A; alachlor + metribuzin 2 + 1/2 lb/A; alachlor + chorobromuron 2+1 lb/A; chlorobromuron 2 lb/A; linuron 2 lb/A; MBR-8251 2 lb/A; R-25823 2 lb/A and S-6044 lb/A. Metribuzin gave satisfactory broadleaf weed control at 1/2 lb/A, but does show some weakness on barnyardgrass control with only a preemergence application. Metribuzin as a split treatment at 1/2 lb/A preemergence and 1/2 lb/A postemergence controlled 100% of the weed population rated. Metribuzin preemergence 1/2 lb/A and bentazone 3/4 lb/A postemergence gave 93-100% control of grasses and broadleaf weeds. Crop injury was not at a high enough level on any of the treatments to cause concern with exception of postemergence chlorbromuron at 2 lb/A; which received a rating of 53% crop injury. Table 1. Preemergence and Postemergence Weed Control Evaluations in Potatoes on Mineral Soil, Montcalm Co., 1973. Planted: May 20, 1973 Treated: Pre-May 31, 1973 Post-June 16, 1973 Variety: Soil Type: Organic Matter: Burbanks Sandy clay loam 2.42 Rated: June 21, 1973 Weeds present: lambsquarter, pigweed, barnyardgrass Tmt. No. Treatment Pre Pre Pre + Post Post Pre + Post Pre Pre Pre Pre Pre Pre + Post Pre Pre Pre Pre + Post Post 1 2 3 4 5 X6 X7 X8 9 10 11 12 13 14 15 16 17 18 19 20 Rate lb/A 1 1/2 1/2+1/2 1/2 1/2+1/2 2+1/2 2+4 1/2 2+1 Sencor Sencor Sencor Sencor Sencor(super) Lasso + Sencor Lasso + DNBP Lasso + Bromex Bromex Lorox Sencor + Basagran 1/2+3/4 M&B 14255 2 2 2 Deston Probe Sencor Maloran Pre Pre Weed free check Weedy check S-6044 S-6044 2 2 1/2+1/4 2 2 4 — — Weed Control Rating Weed Control Rating Injury Grass Bd. Lv. 0.7 0.3 0.3 1.7 0.3 0.0 1.7 0.3 1.3 0.7 0.7 1.0 2.0 1.3 0.7 5.3 1.3 1.3 0 0 10.0 9.3 10.0 9.0 10.0 10.0 10.0 10.0 9.7 9.3 9.3 8.0 10.0 9.7 10.0 7.0 8.0 10.0 10.0 0.0 10.0 10.0 10.0 9.3 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.3 10.0 10.0 0.0 0 = No control and no injury; 10 = Complete control or kill X = Tank mix 1973 POTATO VINE KILLING DEMONSTRATIONS R. W. Chase, W. F. Meggitt and R. C. Bond Department of Crop and Soil Sciences Research plots of potato vine killing treatments were not conducted in 1973 as efforts were directed to on-the-farm demonstrations. Two locations were established in Otsego and Emmet Counties using the Sebago variety. The farm cooperators were Leo Marker of Elmira and Oscar Overholt in Levering. At both locations the growers boom sprayer was calibrated and used for the application. A summation of these demonstrations is as follows: Cooperator: Leo Marker, Elmira Sebago variety Treatments applied September 10. Partially cloudy, 68 F Noon. Treatments Rate/A Ratings* Ratings * Ratings *Sept. 17 Sept. 17 Leaves Stems Leaves Sept. 25 Ratings *Sept. 25 Stems 1. General + oil conc. 2. Des-i-cate 3. Des-i-cate+oil conc. 4. Evik 80W 5. Evik 80W + oil conc. 1 1/2 qt + 1 qt 2 gal 1 1/2 gal + 1 qt 2 1/2 lb 2 lb + 1 qt 25 85 85 10 30 5 60 60 5 10 75 — 90 65 80 70 — 90 65 70 Remarks: Applied with growers boom sprayer at 55 gpa. Treatment 2 was over­ sprayed between September 12 and 25, thus no second rating could be made. Cooperator: Oscar Overholt, Levering Sebago variety Treatments applied September 11 Partially cloudy, 61 F. Treatments Rate/A Ratings * Leaves - Sept. 17 Sept. 17 Ratings * - Stems 1. General 2. General + oil conc. 3. Des-i-cate 4. Des-i-cate 5. Des-i-cate + oil conc 1 1/2 gal + 1 qt 6. Evik 80W 7. Evik 80W + oil conc. 2 qt 1 1/2 qt + 1 qt 1 1/2 gal 2 gal 2 1/2 lb 2 lb + 1 qt 40 50 80 90 90 30 30 20 25 65 80 80 10 10 Remarks: Applied with growers boom sprayer at 57 gpa. Grower used Des-i-cate on balance of field. Grower had oversprayed before September 25, also frost. *Expressed as percent of kill. EFFECTS OF LATE SPRING FUMIGATION ON THE STAND AND YIELD OF FIVE POTATO VARIETIES Ernest C. Bernard Department of Entomology A study of the effects of fumigation on several varieties of potatoes was planned for 1973 at the Montcalm Experimental Farm. Due to wet weather between the time of fumigation and the time of planting, it was believed that the fumigant was not sufficiently released from the soil despite 2 diskings. On April 30, the fumigant Vorlex was applied to one half of a 100 ft. x 50 ft. randomized complete block design with 5 replications. Fumigant was injected about 10 inches beneath the surface with a broad­ cast eleven-shank pump-driven applicator. The entire plot was disked twice, once on May 11 and again on May 14. Planting of 5 varieties (Katahdin, Kennebec, Norchip, Russet Burbank, and Superior) was done on May 18. Russet Burbank and Norchip were planted at 12 inch intervals, the others at 10 inch intervals. Rows within a block were 3 feet apart. The west 100 x 20 ft. (fumigated) and the east 100 x 20 ft (non-fumigated) were planted, leaving a 10 x 100 ft. buffer planting between them. Fertilizer treatments consisted of 600 lbs/acre 20-10-10 banded at planting, and a sidedress of 70 lb/acre nitrogen on each of June 13 and June 21. EFFECT ON EMERGENCE The number of plants produced was counted after emergence was completed. The results, tabulated in Table 1, indicate that the fumigated side of the plot suffered sprout losses in every variety. The Norchip results may be artificially low due to the poor condition of the seed at planting. Table 1. The effect of late soil fumigation on the emergence of 5 varieties (F: fumigated; N: not fumigated). empty table cell No. of Plants Emerged No. of Plants Emerged No. of Plants Emerged No. of Plants Emerged R. No. of Plants EmergedKATAHDIN No. of Plants EmergedKATAHDIN No. of Plants Emerged KENNEBEC KENNEBEC NORCHIP NORCHIP BURBANK No. of Plants Emerged R. BURBANK No. of Plants Emerged SUPERIOR No. of Plants Emerged SUPERIOR F 21 25 16 17 16 N 22 25 19 21 22 F 14 16 13 19 5 N 22 19 19 17 13 F N 14 12 8 5 6 16 16 13 12 16 F 16 19 16 17 18 N 18 20 21 19 18 F 20 17 20 18 18 N 21 21 21 18 18 Block 1 Block 2 Block 3 Block 4 Block 5 Total plants Possible plants % Stand 95 120 79 109 120 91 67 120 56 90 120 75 45 100 45 73 100 73 86 100 86 96 100 96 93 120 78 100 120 83 Because most fumigants are phytotoxic, these results indicate that 2 diskings were not sufficient to release the fumigant gas. It is believed that the wet conditions of the spring partially sealed the soil, even after disking, and trapped fumes still in the soil. Yields of each variety were graded and weighed to determine the effect of fumigation on tuber production. The yields for each row, fumigated and non-fumigated, are tabulated in Table 2. Besides showing that the 19 day interval between fumigation and planting was not long enough, the data also indicate that some varieties are more tolerant of at least this phytotoxic fumigant (Vorlex) than are other varieties. EFFECT ON YIELD Varieties were harvested on September 21, hand-graded, and weighed. Later, average yields/plant were computed. The results show, in contrast to the stand results, that the yield/plant in the fumigated area was higher than in the non-fumigated area. Table 2. Effect of fumigation on the yields of 5 varieties (yields in lbs. per plot). empty table cell KATAHDIN KATAHDIN KENNEBEC KENNE BEC NORCHIP NORCHIP R. BURBANK R. BURBANK SUPERIOR SUPERIOR F N F N F N F N F N Block 1 Block 2 Block 3 Block 4 Block 5 61.0 51.6 62.0 67.5 59.5 63.0 56.0 62.0 68.5 65.5 42.0 52.2 65.0 66.0 39.0 48.0 61.5 69.0 9.5 42.0 34.0 43.4 15.0 38.0 27.5 27.0 11.5 33.5 35.5 14.0 36.5 41.0 61.0 51.0 46.0 49.0 53.0 37.5 45.5 55.5 46.5 35.5 59.5 48.0 52.5 46.0 45.0 44.5 41.0 58.5 Total Yield 301.6 315.0 No. of Plants 95.0 109.0 3.17 2.89 Yield/plant 217.2 277.2 67.0 90.0 3.08 3.24 108.0 168.5 73.0 45.0 2.40 2.33 226.5 249.5 96.0 86.0 2.60 2.63 244.5 232.5 93.0 100.0 2.33 2.63 Analysis of the yield showed that there was a greater proportion of tubers over 1 7/8" in the fumigated areas than in the non-fumigated, and, in the Russet Burbanks, a much higher proportion of oversized tubers and offtypes. It is probable, therefore, that the fumigated plants were provided more room for tuber growth because of the poorer stands, and that this extra space may account for the increase in yield per plant. CONCLUSIONS The usual recommendation is that fumigation precede planting by at least 3 weeks and fall applications are preferable. The above results indicate that for a spring application a longer time may be required particularly if the weather is rainy and the gound wet, heavy and cold. Further tests are to be conducted next year. 1973 GRAIN SORGHUM HYBRID TRIAL Stuart Hildebrand Department of Crop and Soil Sciences Eight grain sorghum hybrids were selected based on their previous record in SW Michigan tests. Seed was planted on June 7 in 2 row plots, 34 inch rows, 20 feet long and each variety was replicated 4 times. A combination of Atrazine and Ramrod at 1 and 3 pounds per acre respectively, active ingredient, was applied preemergence for weed control with good results. Six varieties were harvested on October 11 and 1 on October 24 with all varieties showing some bird damage. One very early variety was damaged almost 100% by birds and was not harvested for yield. Yield per acre and moisture percent at date of harvest are listed below: Hybrid NK 121 Pride 550 BR Pride 500 A S. Dak. 104 S. Dak. RS 506 DeKalb A-26 Dorman 100 RB Yield per Acre @ 14% moisture % moisture in grain on the date of harvest 53.4 75.3 63.3 47.3 74.0 56.9 89.8 22.0 (Oct. 11) 22.0 (Oct. 11) 24.5 (Oct. 11) 25.0 (Oct. 11) 31.5 (Oct. 11) 38.0 (Oct. 11) 30.5 (Oct. 24) This is the second year of grain sorghum hybrid trials at this location. Six hybrids were tested in 1972. Average yields for those hybrids entered in the trials both years are given below along with other pertinent information: Hybrid NK 121 Pride 500 A So. Dak. RS 506 Dorman 100 RB 2 Yr. Aver. Yield per acre @ 14% moisture 64.6 63.2 64.4 81.6 Remarks Matured both years Slightly immature in 1972 Matured both years Considered slightly late both years BEAN BREEDING PROJECT M.W. Adams, A.W. Saettler and Jerry Taylor Department of Crop and Soil Sciences The results of a test of several colored bean varieties and strains grown at a 14-inch and a 28-inch row width are shown in the accompanying table (Table 1). The following conclusions can be drawn: 1. There is no consistent advantage to the 14-inch row width for colored beans at this location, and under the fertility and moisture status that prevail. 2. There is no consistent evidence that certain varieties or growth types do relatively better at the narrower spacing. 3. Late-maturing strains have performed relatively better in yield than early-maturing strains. 4. As in recent previous years, Swedish Brown and Black Turtle Soup beans have given the best yields. This may be due to their higher harvest indexes, which is a measure of the partition efficiency of the variety, that is, the proportion of total growth or dry weight that is apportioned to seeds. It is interesting to note in this connection that the third highest ranking strain in yield, Michigan Improved Cranberry, was also relatively high in harvest index. 5. There is rather good agreement in harvest index between the 14- and 28-inch row widths for most varieties. 6. On the basis of all available data, including 1973, the red kidney strains 023 and 03, dark red and light red respectively, have been approved for release as new varieties to replace Charlevoix and Manitou. The principal advantage is in halo-blight resistance. The new strains will not differ from the standards in yield or maturity. Table 1. Yield and Harvest Index results from a test of miscellaneous Colored Beans grown at 2 row widths on the Comden Farm, 1973. Variety or Strain Charlevoix DRK Calif. Dark R. Kid. DRK 023 Manitou LRK LRK 03 Redkote LRK Mich. Imp. Cranberry Expt. Cran. 026 Expt. Cran. 027 Expt. Cran. 028 2833 2342 3073 2511 2734 2843 2651 2486 2543 Commercial Yellow Eye 2347 Swedish Brown LRK 01 Black Turtle Soup Big Bend Red Mexican Averages 3317 2827 3032 2421 2687 Yield in lbs/A 28" rows 2342 lbs/A Yield in 14" rows 2647 Average yield in lbs/A over both row widths 2494 Harvest Indexes* Indexes* Harvest 14" rows 53.1 28" rows 51.4 2686 2251 2290 2612 1995 2772 2777 2874 2201 2656 3385 2345 3319 2392 2614 2760 2296 2682 2562 2364 2808 2714 2680 2372 2502 3351 2586 3176 2406 2650 47.1 43.9 48.7 40.7 41.8 51.9 50.0 51.1 42.3 47.8 58.4 47.0 61.1 49.7 48.3 48.5 47.6 49.2 56.6 50.6 49.9 48.9 51.5 58.2 48.7 59.1 56.0 55.7 empty table cellempty table cell *Harvest Index is the ratio (X100) of weight of seed to total air-dry weight of plant and seed at harvest time. EVALUATION OF PICKLING CUCUMBERS PLANTED WITH STANHAY AND DAHLMAN SEEDERS J. E. Motes Department of Horticulture The objectives of this study were to evaluate the plant population established and the subsequent yield of pickling cucumbers planted with Stanhay and Dahlman precision seeders. Procedure Pickling cucumber varieties Premier and Spartan Jack were planted with Stanhay and Dahlman seeders. Both seeders were calibrated to space seed drops five inches apart in the row. Four rows were planted 16 inches apart on seven foot beds. (A single plant es­ tablished every 5 inches would result in 60,000 plants per acre.) Seed germination for Premier and Spartan Jack was 70 and 90% respectively. Plots were hand harvested when the estimated dollar value per acre was greatest. TABLE 1. Established pickling cucumber plant populations observed from 60,000 seed drops per acre with two varieties using two seeding machines. Variety and Seeder Plants Per Acre Percentage of Plants Growing As: Singles Percentage of Plants Growing As: Doubles Percentage of Plants Growing As: Percentage of Plants Growing As: Triples Quadruples Premier -Stanhay seeder Premier -Dahlman seeder Spartan Jack -Stanhay seeder Spartan Jack -Dahlman seeder 32,000 24,000 59,000 44,000 55 100 40 86 38 0 22 14 8 0 21 0 2 0 17 0 TABLE 2. Yield and grade size distribution of pickling cucumbers from two varieties seeded with two seeding machines. Variety and Seeder Plants Per Acre Yield* Yield* $/A bu/A To 1 1/16" Grade size (% by wt) Grade size (% by wt) 1 1/16"- 1 1/2" Grade size (% by wt) 1 1/2"- 2" 63 60 56 50 Grade size (% by wt) Over 2" 7 24 11 20 Value $6.00/bushel $3.00/bushel $2.00/bushel No value Premier -Stanhay seeder 112 Premier -Dahlman seeder 112 Spartan Jack -Stanhay seeder 143 Spartan Jack -Dahlman seeder 154 * Bu/A based on pickles less than 2" in diameter 32,000 24,000 59,000 44,000 $/A based on the following values: 275 257 374 400 4 2 7 6 26 14 26 24 Grade Size up to 1 1/16" 1 1/16" - 1 1/2" 1 1/2" - 2" over 2" Results and Discussion Vegiben 2E at 1.5 lb/A did not give satisfactory control of barnyard grass which com­ peted with the pickling cucumbers. Fifty lb/A of N was broadcast incorporated on all plots. One half of the plots were sidedressed with an additional 50 lb N/A at vine tip over. Yield and grade size distribution was not influenced by the N sidedress application, so the data was combined in the tables. The results shown in Table 1 indicate the Dahlman seeder resulted in fewer plants being established per acre than with the Stanhay seeder. The Stanhay seeder tended to "clump plant" pickling cucumber seeds while the Dahlman gave a high degree of singulation. Since both seeders were releasing seeds 60,000 times per acre, more seeds were planted per acre by the Stanhay seeder. No difference in yield per acre of pickles resulted between the two seeders (Table 2). All plots of a variety were harvested on the same day. However, the percentage of cucum­ bers over 2 inches in diameter was greater in both varieties when planted with the Dahlman seeder. This indicates either slightly faster development under lower plant population or slightly faster development due to the high degree of singulation. 6/15/73 Vegiben 2E 1. 5 lb/A pH = 6.1, P = 275, K = 225 50-0-100 Planted: Herbicide: Soil Test: Fertilizer: Sidedress N: Irrigation: Harvest Area: 210 sq. ft. Days from planting to harvest: Premier - 50 days Spartan Jack - 52 days 50 lb N/A 7/18/73 2 inches CORN HYBRIDS, PLANT POPULATION AND IRRIGATION E. C. Rossman and Bary Darling Department of Crop and Soil Sciences Table 1 presents performance data for 72 commercial and experimental hybrids evaluated in 1973 with irrigation and without irrigation. Five inches of irrigation water were applied (1 1/4" on July 13 and 24, August 17 and September 1). Buoyoucous soil moisture blocks were placed at 6, 12, 18 and 24-inch depths in both irrigated and unirrigated plot areas. Irrigated yields in 1973 were the lowest obtained at the Montcalm farm during the 6 years, 1960-1973 (Table 2) — 113.6 irrigated versus 101.0 unirrigated. The average difference in favor of irrigation was only 12.6 bushels (12.5%). During the previous 5 years, 1968-1972, irrigated yields averaged 149.1 and not irrigated yields averaged 89.8 — a difference of 59.3 bushels (66%). Wet soil conditions at and following planting hindered early growth and development. Soil moisture was below 50% water holding capacity at all soil depths (6-24") in both irrigated and unirrigated plots during the last 10 days of August. Reduced soil moisture and 90°F and above temperatures created a stress during late August and early September in both irrigated and unirrigated areas. Soil moisture data indicated that the irrigated areas received inadequate moisture during this stress period. Hybrids ranged in yield from 78.4 to 137.5 irrigated and 72.9 to 119.7 not irrigated. Irrigation response of the highest yielding hybrid was about 7 times greater for the highest yielding hybrid than for the lowest yielding hybrid, 19.7 versus 2.8 bushel increases from irrigation. Hybrids significantly better than the average yield (arranged in order of increasing grain moisture content at harvest) are listed on the following page. Twenty one of these 24 hybrids were in the highest yielding group for both irrigated and unirrigated plots. Irrigated Not Irrigated Michigan 396-3X (3X) Mich. Exp. 71-2069 (2X) Michigan 410-2X (2X) Migro M-1101 (2X) Mich. Exp. 71-2002 (2X) Now Michigan 407-2X Mich. Exp. 71-2665 (2X) Blaney BX-AA (2X) Asgrow RX53 (2X) Migro M-1212 (2X) Pioneer 3780 (2X) Mich. Exp. 71-2915 (2X) Funk 26191 (2X) Now G4321 Michigan 572-3X (3X) Super Crost S27 (2X) Funk G4366 (3X) Mich. Exp. 71-2831 (2X) Michigan 500-2X (2X) Acco UC3301 (2X) Michigan 511-3X (3X) P.A.G. SX69 (2X) Migro M-Exp. 1130 (2X) Funk G4444 (2X) Acco UC3201 (2X) Migro M-0501 (2X) Michigan 396-3X (3X) Michigan 410-2X (2X) Migro M-1101 (2X) Mich. Exp. 71-2002 (2X) Now Michigan 407-2X Mich. Exp. 71-2665 (2X) Blaney BX-AA (2X) Asgrow RX53 (2X) Migro M-1212 (2X) Pioneer 3780 (2X) Mich. Exp. 71-2915 (2X) Funk 26191 (2X) Now G4321 Michigan 572-3X (3X) Super Crost S27 (2X) Funk G4366 (3X) Acco UC3301 (2X) Michigan 511-3X (3X) P.A.G. SX69 (2X) Migro M-Exp. 1130 (2X) Funk G4444 (2X) Acco UC3201 (2X) Migro M-0501 (2X) Plant Population X Irrigation Five hybrids at 4 plant populations irrigated and not irrigated were grown in each of 6 years, 1968-1973, Table 3. In 1973, highest yields were reached at a population of about 19,200 for both irrigated and unirrigated plots. Yields decreased as population was increased to 23,100 and 27,300 for both irrigated and unirrigated. In 5 previous years, 1968-1972, highest yields with irrigation were reached at a population of about 23,100 — 4,000 more plants per acre than without irrigation. Irrigated yields at all 4 populations were lower in 1973 than in any of the previous 5 years. Inadequate irrigation and 90°F or above temperature during late August and early September appeared to have reduced response to irrigation. Table 1 NORTH CENTRAL MICHIGAN Montcalm County Trial - Irrigated vs. Not Irrigated One, Two, and Three Year Averages - 1973, 1972, 1971 % Moisture % Moisture % Bushels per Bushels per Bushels % Stalk lodging % Stalk lodging acre 2 Years Irrig acre 2 Years Not Irrig per Bushels per acre 3 Years Not Irrig acre 3 Years Irrig % % Stalk lodging 1972Irrig Stalk lodging 1972Not Irrig Years Irrig 2 2 Years Not Irrig Zone 3 % Stalk lodging 3 Years Irrig % Stalk lodging 3 Years Not Irrig Hybrid (Brand---Variety) 2 Yrs 1972 Moisture3 Yrs Bushels per acre 1972Irrig Asgrow RX30(2X) Michigan 280(4X) Michigan 275-2X(2X) Teweles TXT53X(3X) Mich.Exp.68-3613(3X) Mich.Exp.63-3635(3X) DeKalb XL311 (3X) Jacques JX863(3X) Funk G4195(3X) Blaney B2OO(2X) Wolverine 24(4X) Michigan 333-3X(3X) Asgrow Rx42 (2X) Acco UC1901 (2X) Super Crost 1692(2X) 20.1 20.5 20.7 20.8 21.0 -- 21.3 21.5 -- 21.7 21.9 22.0 22.0 22.3 22.8 23.0 23.1 Michigan 396-3X(3X) 23.2 Stanton SX1095N (3X) 23.5 Stanton SX1O9ON (3X) 23.5 Wolverine W128 (2X) 23.8 Mich.Exp.71-2001A 9(2X) 23.9 Mich.Exp.71-2001(2X) DeKalb XL12 (2X) Pioneer X9379A(3X) Cowbell SX102(2X) Pride R252(2X) 24.0 24.1 24.2 24.2 24.2 -- 23 23 -- -- 25 — — -- — 25 -- -- -- 26 — -- -- 27 27 — -- 27 -- -- 24 23 -- -- — -- — -- — -- 25 -- -- -- 26 — -- -- -- -- -- — 26 -- 90.9 99.6 103.7 83.2 113.6 112.5 103.3 79.6 100.3 78.4 89.7 117.2 117.8 109.7 105.8 129.1 92.1 90.2 106.0 108.5 116.6 104.6 100.7 118.2 81.0 Bushels per acre 1972 Not Irrig 81.2 93.0 95.9 73.7 101.7 103.4 87.4 77.2 85.9 75.6 77.1 105.8 106.9 103.3 89.6 111.2 81.0 93.1 -- 86.3 88.0 105.4 94.6 90.9 108.4 75.5 -- -- 118 115 -- — 108 98 — -- -- -- — 96 — — -- 131 — — 141 -- -- 129 136 -- -- 127 -- -- -- -- 84 -- -- 121 -- — -- 129 -- -- -- 106 120 -- -- 117 -- — 130 126 -- -- -- -- -- -- -- -- -- 143 — -- -- -- 154 -- -- — — -- -- -- — 133 -- -- 81 75 -- -- -- — -- — -- -- 94 -- -- 92 — -- — -- --__ 90 4.0 3.4 5.2 4.1 5.0 2.7 4.9 7.4 3.2 4.1 0.0 4.3 1.7 4.3 4.8 3.1 2.7 13.8 0.0 5.3 5.3 4.0 0.9 4.7 3.7 -- 8 10 -- -- — -- 19 -- -- -- -- 8 -- -- — -- -- 4 -- — -- -- -- 5 -- -- 3 8 5.9 3.9 7.2 6.7 7.0 7.0 4.6 5.0 7.8 8.2 3.2 2.0 2.0 5.1 2.8 2.8 2.2 2.1 2.9 2.4 -- 3.0 2.1 -- 2.2 -- 2.8 -- 8.3 — 8 4 -- -- -- -- 14 -- 2 4 2 2 4 -- -- 8 9 -- -- -- -- -- -- 6 -- 5 -- -- -- -- -- -- -- -- -- -- 7 3 -- -- -- -- -- -- -- -- -- -- -- -- 6 3 -- — -- -- -- -- -- 1 -- 3 -- -- Table 1 Continued Mich.Exp. 71-2069(2X)1 24.5 Michigan 410-2X (2X)1,2 24.5 Migro M-1101 (2X) 1,2 24.7 Mich.Exp, 71-2002(2X)1,2 24.7 Blaney B401 (2X) 24.8 -- -- 127.5 132.6 28 28 135.4 135.0 28 -- — 118.1 27 -- -- -- -- 28 97.1 102.2 84.0 124.6 28 28 — 112.1 __ 31 27 __ Pioneer 3958(2X) 24.8 27 DeKalb XL15A(2X) 24.8 25.0 — -- Tewelee 263NBT(4X) Jacques JX162A(2X)1 28 25.4 Funk G4343(2X) 25.4 Mich.Exp. 71-2665(2X)1,2 25.5 29 25.6 Super Crost S25(2X) -- Funk G4252(3X) 25.6 Funk 26189(3X)1,2 25.6 — -- -- 25.6 Teweles SXT14(2X) Blaney BX-AA(2X)1,2 Pride R290(2X) Asgrow RX53(2X)1,2 Acco DC231(4X) Pioneer 3786(2X) 25.6 29 28 25.7 25.8 — -- 25.8 26.2 135.0 118.0 86.4 130.8 81.2 29 29 125.1 109.4 132.0 -- — 88.4 -- — 111.6 -- Acco UC2301(2X) Migro M-1212 (2X)1,2 Super Crost 1712(2X) Pioneer3773 (2X) Acco U334 (3X) 26.4 26.4 26.6 26.7 26.7 27 -- -- 120.9 28 -- 126.6 29 102.9 -- — 127.3 29 99.7 -- -- -- Cowbell SC73OO (2X) 27.2 Pioneer 3780(2X)1,2 27.2 Blaney B501a(2X) 27.3 Mich.Exp. 71-2915(2X)1,2 27.4 Funk 26191(2X) 1,2 30 30 -- 27.4 — 113.7 -- 126.2 -- 109.2 -- 137.3 — 124.5 110.2 110.9 112.7 118.0 93.5 92.3 94.0 72.9 97.8 103.9 -- 144 143 167 -- 119 -- 142 144 152 121 -- -- -- 116.8 101.8 85.9 110.6 76.8 -- 115.0 93.7 119.7 — 86.5 98.5 -- 152 144 -- 107.3 117.8 94.2 106.8 91.8 98.4 111.3 102.3 117.4 113.6 -- 142 -- 129 — 132 154 138 -- — -- 127 125 144 -- 108 — 113 123 127 107 — 135 129 — -- -- -- — -- 127 — 116 -- 112 -- 134 118 — -- -- — -- -- — 162 -- -- -- 137 -- 156 -- -- 164 -- — 163 158 -- 154 -- -- -- -- -- -- -- -- - - 95 -- — -- 82 -- 87 -- 90 — -- -- -- -- 100 93 — — -- -- 91 -- -- -- -- — -- -- — 10.5 4.3 3.1 5.0 0.8 2.6 3.3 6.5 5.5 1.6 3.3 0.8 3.2 5.7 6 .5 1.5 5.5 0.7 8.8 4.0 6.7 2.3 1.8 0.8 2.6 5.8 4.9 3.1 6.6 5.6 7.3 6.5 2.0 3.8 3.5 2.7 1.9 7.0 0.0 0.9 0.9 0.0 4.5 0.9 7.4 2.8 2.6 3.5 4.0 1.1 1.0 0.0 2.1 3.1 1.3 2.9 3.2 1.1 4.9 2.1 -- 5 3 6 -- -- 12 — 10 5 -- 4 7 -- -- 4 8 -- -- — 10 -- 5 -- 6 8 6 -- -- -- -- 5 1 3 -- 7 -- 2 1 4 3 -- -- 5 6 -- -- -- 3 -- 2 -- 1 2 2 -- -- -- -- -- -- -- 7 -- -- -- -- 10 -- 12 -- 4 -- -- -- 4 3 — -- -- 9 — -- -- -- __ -- -- -- — -- -- -- -- 3 -- -- -- 5 -- 2 -- 3 -- -- -- 3 4 -- -- -- 3 — -- -- -- -- -- — -- Table 1 Continued 29 Michigan 572-3X(3X)1,2 27.4 133.8 29 -- — 116.3 27.4 DeKalb XL21(2X) Super Crost S27(2X)1,2 27.7 134.6 31 27.8 — — 110.5 Stanton SX10100(3X) Funk G4366(3X)1,2 134.6 27.8 Mich.Exp. 71-2831(2X)1 27.8 — — 135.9 110.8 Renk R235A(3X) Michigan 500-2X(2X)1 128.9 Acco UC3301 (2X)1,2 136.9 Blaney 6616 (Sp.) 104.3 27.9 28.0 28.2 28.3 — 30 -- -- -- 31 31 -- -- 30 -- Michigan 511-3X(3X)1,2 28.3 P.A.G SX69(2X)1,2 28.3 Migro M-Exp.1130(2X)1,2 28.5 Cowbell SX112(2X) 28.5 Funk G4444(2X)1,2 28.8 30 31 -- — 30 31 30 30 -- 30 128.3 135.8 127.9 110.5 133.9 116.8 106.4 — 118.2 101.1 120.4 109.2 103.0 108.9 118.8 94.7 113.5 116.7 114.8 102.8 116.9 160 154 — -- — -- 154 160 — — 158 169 — — 140 169 155 Acco UC3201 (2X)1,2 Migro M-0501 (2X)1,2 Average Range 28.8 31.8 25.2 31 — 137.5 — 133.6 — 117.8 110.9 — 28 28 113.6 101.0 142 20.1 to 31.8 23 to 31 23 to 30 78.4 to 137.5 72.9 to 119.7 96 to 169 137 -- 139 — — — -- 134 134 — 143 139 — 121 — 140 131 -- 123 84 to 144 168 — 165 — -- — -- 164 -- — — 175 175 — — — 178 — -- 156 126 to 178 100 -- 102 -- -- -- -- 99 -- 105 — — 105 — 94 2.4 3.6 4.6 4.8 4.0 2.0 2.5 3.5 6.1 3.0 2.5 2.4 1.8 3.4 4.8 2.3 0.0 3.9 4.1 5.1 3.9 1.0 2.7 2.4 6.3 2.2 10.3 3.2 4.0 5.5 1.9 — 3.7 1.7 1.7 0.0 3.5 75 to 105 0.0 to 13.8 0.0 to 10.3 6 -- 6 — — — — 5 5 4 3 11 5 3 — 7 3 to 19 4 — 3 — — — -- 1 7 — — 6 — 5 — — — — 6 — — — — — — 4 3 3 4 3 -- 4 1 to 14 4 4 — — — 6 — — 7 4 to 12 3 — 2 — -- — 1 — 3 2 3 -- 3 1 to 6 Least significant difference 1.0 .7 .5 10.8 9.5 7 6 5 5 1 Significantly better than average yield, irrigated 1973. 2 Significantly better than average yield, not irrigated, 1973. empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell Table 1 Continued empty table cell Planted Harvested Soil type Previous crop Population Rows Fertilizer Soil test: pH Soil test: P Soil test: K Irrigation 1973 May 8 Oct. 17 Montcalm sandy loam Sorghum-sudan seeded to rye in fall 18,700 30" 277-130-130 5.6 297 (very high) 175 (medium) 5 inches 1972 1971 May 5 Oct. 25 Montcalm sandy loam Sorghum-sudan seeded to rye in fall 20,100 30" 258-145-145 5.5 420 (very high) 178 (medium) 6 inches May 6 Oct. 29 Montcalm sandy loam Sorghum-sudan seeded to rye in fall 20,300 30" 160-140-140 6.0 340 (very high) 246 (high) 12.5 inches Farm Cooperator: Theron Comden, Lakeview County Extension Director: James Crosby, Stanton Table 2. Average, highest, and lowest yields for corn-hybrids irrigated and not irrigated for 6 years, 1968-1973. Average Average Highest Highest Not Irrigated Not Irrigated Lowest Lowest Not Irrigated Irrigated Year 1973 1972 1971 1970 1969 1968 No. of hybrids tested 72 72 56 64 63 56 Irrigated 113.6 157.3 162.5 143.6 146.0 136.1 Irrigated 137.5 206.3 210.5 193.8 184.9 182.2 101.0 136.6 28.2 102.9 85.5 96.0 119.7 179.1 41.9 127.7 108.6 123.2 78.4 98.5 91.0 94.9 96.7 92.2 72.9 90.5 10.6 69.6 56.3 65.4 60.9 Averageempty table cell 143.2 91.7 185.8 116.7 92.0 Irrigation: 1973 = 5" July 13 = 1.25" July 24 = 1.25" Aug. 17 = 1.25" Sept. 1 = 1.25" 1969 = 6" July 26 = 1.5" Aug. 8 = 1.5" Aug. 14 = 1.5" Aug. 27 = 1.5" 1972 = 6" July 7 =1.5" July 11 = 1.5" July 24 = 1.5" July 30 = 1.5" 1968 = 7.5" July 16 = 1.5" Aug. 2 = 1.5" Aug. 12 = 1.5" Aug. 20 = 1.5" Sept. 7 = 1.5" 1971 = 12.5" June 23 = .75" June 27 = 1.0" July 3 =1.0" July 7 = .75" July 12 = 1.0" July 16 = 1.0" July 23 = 1.0" July 27 = 1.0" Aug. 2 = 1.0" Aug. 6 = 1.0" Aug. 13 = 1.0" Aug. 17 = 1.0" 1970 = 5.5" July 20 = 1.0" July 27 = 1.0" July 30 = 0.5" Aug. 4 =1.0" Aug. 11 = 1.0" Aug. 13 = 1.0" Table 3. Average yield at 4 plant populations irrigated and not irrigated for 6 years, 1968-1973. 15,100 Irrigated 15,100NotIrrig. 19,200 Irrigated 19,200Not Irrig. 23,100 Irrigated 23,100Not Irrig. 27,300 Irrigated 27,300Not Irrig. 107.5 151.9 172.9 122.2 125.5 143.5 97.1 132.4 36.6 91.0 90.7 113.9 134.3 186.5 189.1 144.1 157.5 169.3 115.5 158.8 35.3 111.7 108.5 130.2 127.6 191.2 190.9 158.2 173.2 193.1 105.5 149.3 20.2 93.4 95.7 107.0 108.0 161.2 180.6 151.2 147.8 178.4 101.8 143.9 10.5 85.1 86.3 89.4 Year 1973 1972 1971 1970 1969 1968 Average 137.3 93.6 163.5 110.0 172.3 95.2 154.5 86.1