1972 Research Report MONTCALM EXPERIMENTAL FARM Michigan State University Agricultural Experiment Station ACKNOWLEDGEMENT 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 INTRODUCTION, WEATHER, AND GENERAL MANAGEMENT................................................................. 1 Page A. POTATO STUDIES Introduction of New Varieties N. R. Thompson and R. W. Chase ............................................................ 5 Potato Breeding N. R. Thompson......................................................................................................................... 8 Plant Spacing Studies R. W. Chase.......................................................................................................................................10 Soil Fertility Research with Potatoes M. L. Vitosh...................................................................................................................................12 Variety Stage of Growth Study in Potatoes with Sencor J. S. Ladlie, W. F. Meggitt and R. C. Bond..................................................................27 Weed Control Evaluations in Potatoes on Mineral Soils J. S. Ladlie, W. F. Meggitt and R. C. Bond..................................................................33 Vine Killing Evaluation in Potatoes in 1972 J. S. Ladlie, W. F. Meggitt, R. W. Chase, and R. C. Bond....................................35 Insecticide Evaluation for Pest Management of Potatoes A. L. Wells....................................................................................................................................... 37 Phosphorus-Potassium Soil Test Correlation Study D. R. Christenson, C. Bricker and F. Wedel..................................................................44 Water Management of Potatoes Ana Garay, R. J. Kunze, R. W. Chase and E. Kidder.....................................................46 The Effect of Harvest Date and Storage on the Yield Potential of Onaway and Sebago Seed Potatoes R. W. Chase.......................................................................................................................................54 The Relationship of Planting Date, Harvest Date, and Storage on the Yield Potential of Russet Burbank Seed Potatoes R. W. Chase.................................. 59 B. OTHER CASH CROPS Soil Fertility Research with Dent Corn, Sweet Corn, and Dark Red Kidney Beans M. L. Vitosh...................................................................................................................................61 Insecticide Evaluation for Bean Insect Control A. L. Wells....................................................................................................................................... 71 Preplant Incorporated and Preemergence Herbicides for Weed Control in Field Beans D. L. Wyse, W. F. Meggitt, and R. C. Bond.............................. 72 Report of Results of Dry Bean Variety Test M. W. Adams...................................................................................................................................... 75 1972 Grain and Sorghum Trials S. Hildebrand........................................................... 77 Corn Hybrids, Plant Population and Irrigation E. C. Rossman and B. M. Darling............................................................................................ 78 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 six years of studies. The 80 acre facility is leased from Mr. Theron Comden and is located in west-central Michigan one mile west of Entrican, Michigan. The farm was established primarily for research on potatoes and is located in the heart of a major potato producing area. Crops commonly used in a rotation with potatoes are also being investigated. This report is designed to coordinate all of the research data obtained at the facility during 1972. 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 recommen­ dations can be made. Weather Temperature and rainfall recordings for the 1972 growing season are shown in Figure 1. Tables 1 and 2 summarize the 5 year rainfall and temp­ erature data. Average maximum temperatures for 1972 were below the five year average in June, July, August and September of 1972 but were considerably higher in May. There was little deviation in the average minimum temperature. The longest extended warm period occurred between May 19 and 30 when the maximum daily temperature exceeded 80F. Only on one day, July 12, did the temperature reach 90F. The lowest recorded temperature occurred on June 11 with a reading of 29F. Only very slight frost damage was noticed and this appeared on an occasional leaf. Other production areas reported more serious damage. Several below freezing readings occurred in October, the first on October 9 and 10 with low temperatures of 29F and 30F, respectively. It again dropped to 27F on October 13 and 15, however, the most damaging freezes occurred on October 17, 18, 19, 20 and 21 with temperatures of 26, 19, 21, 24 and 30F. An 8 inch depth soil temperature reading made on October 20 under an unharvested row of potatoes was 39F. Rainfall was adequate and uniformly distributed throughout the entire growing season. The total rainfall compares very closely with the five year average, however, it was considerably greater than 1971. The five year summary tabulations show the 1971 season to be an unseasonably dry year whereas 1970 was unseasonably wet in terms of totals. Irrigation applications were reduced considerably with 5 applications of approximately 1 inch each and these were all applied in July. Empty Table cell APRIL SEPT. AVERAGE MAX. 47 MAX. 69 MONTHLY MIN. 30 MIN. 49 1.35 inches 1.96 inches 2.51 inches 3.83 inches 7.28 inches 2.60 inches AUGUST MAX.76 MIN. 57 JULY MAX. 79 MIN. 57 TEMP. RAINFALL MAY MAX. 70 MIN. 47 JUNE MAX. 72 MIN. 50 Figure 1. Climatology Observations at the Montcalm Experimental Farm in 1972. TABLE 1. The five year summary of recorded maximum and minimum temperatures during the growing season at the Montcalm Experimental Station. April Apri Ma May June Jun July July Augus Septembe Septembe Max l Min y Max Min Max e Min Max Min August Max t Min r Max r Min 61 56 54 53 47 54 37 35 35 31 30 34 62 67 65 65 70 66 41 43 47 39 47 43 74 70 72 81 72 74 53 50 55 56 50 53 80 80 80 82 79 80 55 59 60 55 57 57 81 82 80 80 76 80 58 56 57 53 57 56 74 73 70 73 69 72 50 49 51 54 49 51 Year 1968 1969 1970 1971 1972 5 Yr. Ave. TABLE 2. The five year summary of precipitation recorded during the growing season at the Montcalm Experimental Station (inches per month). May 4.90 3.65 4.09 0.93 1.96 3.11 June 3.74 6.18 4.62 1.50 2.51 3.71 July 1.23 2.63 3.67 1.22 3.83 2.52 August Sept. 1.31 1.79 6.54 2.67 7.28 3.92 3.30 0.58 7.18 4.00 2.60 3.53 Total 17.32 18.16 28.52 11.91 19.53 19.10 Year 1968 1969 1970 1971 1972 5 Yr. Ave. April 2.84 3.33 2.42 1.59 1.35 2.31 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: Pounds Per Acre Pounds/Acre Pounds/Acr pH 6.4 P 353 K 259 e Ca 1029 Pounds/AcreMg 177 The preceding crop grown was a rye winter cover crop plowed down just prior to plot establishment. The 1971 crop was Wheeler rye which was harvested for grain. 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 27 and continued on a weekly schedule until terminated on September 3. All spray applications were made with an air blast sprayer. The foliar insecticides used were Endosulfan (Thiodan), Meta-Systox-R,, and Diazinon. The fungicide used was Dithane M-45. Linuron (Lorox) at 1 3/4 lb/A applied preemergence was used for weed control. INTRODUCTION OF NEW VARIETIES N. R. Thompson and R. W. Chase Department of Crop and Soil Sciences Twenty varieties of potatoes were tested for adaptation to the Michigan environment. Plots were located on the Don and Jerry Meyer Farm in Bay County; Andy and Henry Leep Farm in Allegan County; Leon Delekta Farm in Presque Isle County, and the Montcalm Experimental Farm. Planting the plots in the different areas exposes the varieties to a range of climatic and soil conditions which pro­ motes expression of their potential - both good and bad. Result of the 1972 trials are shown in Table 1. Of the white varieties tested, three were outstanding in all locations, Abnaki, Jewel and MS 709. While plot yields varied, the plot yields are indicative of the potential of the variety. The true test is established when growers plant commercial acreages. The variety Sioux is an exceptionally high yielding red. Its good color and white flesh should have appeal in any red marketing area. It has a tendency to oversize but this could be controlled by spacing and vine killing. Chip color and specific gravities of the earlier maturing cultivars were considered good. The wet August and September resulted in poorer chip color of the later varieties. Specific gravity was also adversely affected. Phase II of the variety introduction, i.e. tests on a commercial scale, was initiated. Of the cultivars which merited larger plantings only seed of MS 709 was available. Acreages were planted by: Wayne Lennard, Samaria Paul Lapointe, Dundee Marvin Smith, Erie Robert Johnston, Essexville Andrew Meyer, Saginaw Paul Van Damme, Cornell Ore-Ida Co., Greenville Comments on yield ranged from satisfactory to very good. Neither chip color nor specific gravity was comparable to plot values of previous years. However, only one grower was not interested in an acreage in 1973. His decision was based on chip color. He rated the variety as good for tablestock. MS 709 will be grown commercially in 1973. A more normal season, without frost at both the beginning and end and abnormally wet harvest conditions, may produce different results. MS-709 - a potential high yielding variety that sizes tubers early although the tops may remain green. Shallow eyes and has a tendency to over­ size, however to date hollow heart has been negligible. Medium specific gravity and without adverse conditions it will chip out of the field. Leak and pythium has been observed in storage, however, this may be minimized by proper top killing, conditioning and harvesting. Plant spacing should be 7-8". Jewel - released by private breeders in New York in 1968. A late maturing variety with high specific gravity and an excellent chipper from the field or storage. A potential high yielder with heavy tuber set per hill and a tendency to produce small tubers. Sioux - released in 1969 by Nebraska. A high yielding, late, red variety with very desirable skin color which seems to hold in storage. Tends to oversize so closer spacing and top killing are essential. Abnaki - released in 1970 by U.S.D.A., New York and Maine. Midseason to late maturity with roundish flattened tubers. A potential high yielder, medium to low in specific gravity and may chip out of the field, but not out of storage. Resistant to verticillum wilt and virus leaf roll. Although hollow heart was not observed in our plots in 1971 or 1972 there have been reports that this has been a weakness of the variety. Plant spacing should be 7-8". Raritan - released by Rutgers University. A late maturing variety with high specific gravity. Tubers were not uniformly shaped and the chip ability is variable. Shurchip - released in 1969 by Nebraska. Low specific gravity and its maturity is midseason to late. Its reliability as a chipper is uncertain. Tubers do have a scaly russet on the skin. Hi Plains - released in 1965 by Nebraska. Medium early in maturity, medium to medium-low in specific gravity and the tubers are elongated. It was included in the 1972 trials primarily to determine its adaptation to an earlier variety for frozen processing. Wauseon - released in 1967 by U.S.D.A. and New York particularly because of its resistance to the golden nematode. It is late maturing and is medium in specific gravity. MS-645-2 - midseason cultivar with a potential high yield of very smooth tubers, chips well at harvest. MS-711-3- medium late cultivar with excellent processing quality. Consistently reconditions from storage. Ia-1111-2 - an early cultivar with smooth uniform tubers. Yield and chip quality varies with the season. York - released in 1969 by Canada. Responded as an early maturing variety and was well below average in yield. The results were similar in 1971. Cascade - released in 1969 by the U.S.D.A. and Washington. Appears to be a thin skin variety and storability has been a problem. Fusarium dry rot occurs in storage and if not eliminated reduces stand. Because of this acceptability is questionable. TABLE 1 Montcalm Co. Montcalm Co. Allegan Co. Allegan Co. Presque Isle Co. Presque Isle Co. Bay Co. Bay Co. Average Average Total Yield Specific Gravity Montcalm Co. Chip Color Total Yield Specific Gravity Allegan Co. Chip Color Total Yield Specific Gravity Chip Presque Isle Co. Color Total Yield Specific Gravity Bay Co. Chip Color Total Yield Specific Gravity Average Chip Color Variety MS 709 Jewel Sioux Onaway Abnaki Raritan Shurchip Norchip Hi Plains Wauseon MS645-2 MS711-3 Ia1111-2 Superior York Rushmore 6334-19 63126-2 Haig Cascade Average 5 3 7 8 5 4 4 3 4 4 5 3 5 5 3 4 7 7 322 423 310 365 448 383 288 316 330 271 360 200 247 237 248 1.064 1.078 1.068 1.063 1.068 1.082 1.061 1.068 1.067 1.061 1.073 1.072 1.062 1.066 1.072 1.061 1.075 1.069 3 2 5 7 5 5 3 2 2 3 4 2 3 4 2 2 7 5 639 482 589 412 448 413 407 401 401 435 403 319 253 261 253 297 287 267 619 535 377 466 373 376 1.068 1.086 1.066 1.062 1.066 1.081 1.060 1.077 1.062 1.072 1.087 1.072 1.065 1.075 1.087 1.066 1.076 1.070 1.071 1.069 1.084 1.062 8 5 9 8 8 8 7 3 5 8 6 7 423 438 450 462 383 428 330 306 312 320 314 330 288 267 256 1.074 1.082 1.075 1.067 1.068 1.083 1.069 1.076 1.071 1.074 1.076 1.075 1.066 1.071 1.074 4 2 7 7 4 3 4 2 3 3 4 3 2 4 2 339 336 318 332 276 367 367 280 247 241 491 434 Empty table cellEmpty table cell Empty table cellEmpty table cellEmpty table cellEmpty table cellEmpty table cellEmpty table cellEmpty table cell300 Empty table cellEmpty table cell Empty table cellEmpty table cellEmpty table cellEmpty table cellEmpty table cellEmpty table cellEmpty table cell169 376 340 1.065 1.071 1.079 1.065 1.066 1.072 1.061 1.077 1.076 1.070 1.073 1.064 1.073 1.073 273 401 142 7 7 4 8 9 9 1.070 309 1.068 387 340 338 304 289 261 251 Empty table cellEmpty table cellEmpty table cell 270 Empty table cellEmpty table cellEmpty table cell 393 Empty table cellEmpty table cellEmpty table cell 281 300 169 353 1.068 1.066 1.073 3 7 4 5 May 16 4 May 24 1.073 7 501 470 432 426 413 400 341 340 340 1.070 1.083 1.070 1.064 1.069 1.083 1.064 1.074 1.068 1.068 1.072 1.078 1.064 1.068 1.073 1.062 1.075 1.073 1.068 1.066 1.071 5.0 3.0 7.0 7.5 5.5 5.0 4.5 2.5 3.5 4.5 4.8 3.8 4.3 5.0 2.8 4.1 7.7 7.0 3.0 7.0 4.8 Date Planted:May 16 Date HarvestedSeptember 20 Date ChippedNovember 15 May 16 September 20September 20 November 15November 15 May 24May 24 September 26September 26September 26 November 15November 15November 15 May 31May 31 October 11 October 11 October 11 November 14November 14 November 14 May 1May 1 August 17August 17 August 17 Empty table cellEmpty table cellEmpty table cell September 8September 8September 8 Empty table cellEmpty table cellEmpty table cell May 31 May 1 Empty table cellEmpty table cellEmpty table cell POTATO BREEDING N. R. Thompson Department of Crop and Soil Sciences Unselected Seedlings Approximately 10,000 new seedling tubers grown in the greenhouse in 1971 were planted in the field in 1972. Emergence and growth was vigorous and rapid. Aphids became a problem by September 1 and the plants were killed while most seedlings were in full bloom. However, many outstanding selections were made for tuber set, yield and shape. Processing characteristics will be determined as time permits. Two Hill Clones The unprecedented number of selections made in 1971 were planted as two hill clones, not only to reduce the volume of potatoes that would have to be stored but to determine the amount of disease spread by the severe aphid infes­ tation of 1971. Of the 1550 selections planted 621 or 40% were rogued during the growing season, primarily for virus leaf roll. Only random samplings of families have been made to date. Few were discarded for poor horticultural type in the field and as data is accumulated (weight per hill, specific gravity, chip color, etc.) selections will be made for increase in 1973. A high per­ centage of cultivars appear to have varietal potential as shown in Table 1. TABLE 1 Cross No. Parentage No. Tested Yield/2 hills High Yield/2 hills Mean Yield/2 Hills Low Specific Gravity High Specific Gravity Mean Specific Gravity Low Chip Chip Color Mean Color Good 001 002 003 004 005 006 007 008 010 322-6X709 4 321-38X709 49 321-65X709 7 empty table cell 60 empty table cell 9 empty table cell 4 empty table cell 19 empty table cell 8 empty table cell 5 8.0 5.6 10.5 8.0 7.0 9.9 11.0 6.3 11.5 6.6 9.0 5.5 12.0 7.7 10.5 7.9 12.0 8.5 1.090 1.078 1.066 3 3.5 2.5 1.100 1.079 1.061 1 2 5.0 1.090 1.080 1.074 2.0 1.094 1.078 1.065 1 3 4.5 1.076 1.065 1.053 5 1.079 1.071 1.060 3.5 2 1.072 1.063 1.055 4.5 3.0 1.082 1.068 1.062 4 1.072 1.067 1.060 3 5.5 4 4 3 4 5 6 5 7 5 Chip Color Poor 5 7 5 7 7 7 8 9 6 Advanced Seedling Yield Trial Twenty-nine cultivars were planted in a randomized replicated trial for yield and quality evaluation. Some plots required heavy roguing hence the yield data from these was not utilized. However, 14 selections exceeded the 400 cwt/A minimum requirement. Their performance is shown in Table 1. Before chipping the potatoes were held in 55° storage. Specific gravities and chip color of the later maturing cultivars was generally lower than previous years. Cultivar Total Over 3 1/4" 1 7/8 to 3 1/4" Below 1 7/8 Specific Gravity Chip Color 503-14 711-8 709 321-55 645-1 706-1 613-7 321-89 637 623 706-34 Mer. 249 735-1 Mer. 58 690 639 523 519 504 488 480 472 464 461 437 436 434 425 374 195 203 39 47 19 285 12 00 168 234 62 47 23 296 421 312 441 402 434 164 398 448 281 187 359 367 390 19.5 23.0 8.0 39.0 55.0 35.0 31.0 62.0 16.0 12.0 16.0 15.0 12.0 19.5 1.064 1.064 1.072 1.095 1.084 1.071 1.069 1.115 1.082 1.069 1.068 1.083 1.080 1.067 5 7 8 3 7 3 4 3 9 5 7 5 8 7 MS 709 will be named and released as soon as sufficient seed is available. Its high yield early in the season, attractive appearance, and processing quality at harvest should prove useful in Michigan markets. MS 711-8, a high yielding cultivar with very smooth attractive tubers which cook white will be considered for the tablestock market. Seed will be increased in 1973. PLANT SPACING STUDIES R. W. Chase Department of Crop and Soil Sciences Procedure Two seedlings and three recently named varieties were evaluated in a uniform spacing trial. The identification numbers and names were MS-709, MS-711-3, Abnaki, Jewel, and Shurchip. Planted: Fertilizer: Plowdown 0-0-60 at 200 lb/A May 11, 1972 Planting time 14-14-14 + 2% Mg at 800 lb/A Sidedress 115 lb N/A Harvested: September 19, 1972 Cut seed of each was hand planted at row spacings of 34 inches and plant spacings within the row of 7, 10, 13 and 16 inches. Each plot was 10 feet long and replicated four times. Results and Discussion Table 1 gives a summary of yield, size distribution and specific gravity response for each of the varieties. All were very favorable in terms of yields with MS-709, Abnaki and Jewel showing exceptionally good yield potential. With­ out exception, the greatest total yield occurred at the 7 inch spacing, with decreasing yields at increasingly wider spacings. The size distribution data shows that MS-709 and Abnaki do have a tendency to develop oversize tubers and for this reason a closer spacing of 7-8 inch would be important. To date there has been no evidence of hollow heart as a problem with MS-709, however, there has been some reported with the Abnaki. Based on these observations MS-709 and Abnaki should be spaced at a 7-8 inch plant spacing. The 1972 data differed from that of 1971 in that the specific gravity readings did not relate to plant spacings. In 1971 the specific gravity readings for each of the seedlings MS-709, MS-503 and MS-711-3 was the lowest at the 16" spacing. In 1972 this occurred only with the Jewel variety. The increased plant vigor and initial growth of the closer plant spacings is quite apparent during the early stages of growth. Later in the season when the rows are filled and vines begin to drop, this difference is less obvious. Table 1. The yield, size distribution, and specific gravity of MS-709, MS-711-3, Abnaki, Jewel and Shurchip when grown at different plant spacings. Variety MS-709 MS-709 MS-709 MS-709 MS-711-3 MS-711-3 MS-711-3 MS-711-3 Abnaki Abnaki Abnaki Abnaki Jewel Jewel Jewel Jewel Shurchip Shurchip Shurchip Shurchip In-row space (inches) Total cwt/A Percent Size Distribution -1 7/8 Percent Size Distribution + 3 1/4 Percent Size Distribution 1 7/8 to 3 1/4 Specific Gravity 7 10 13 16 7 10 13 16 7 10 13 16 7 10 13 16 7 10 13 16 582 566 498 490 426 396 395 318 512 440 426 396 576 544 490 446 480 454 434 362 2.3 2.0 2.4 2.0 7.8 7.4 5.0 6.1 3.8 3.1 1.8 2.5 6.8 4.7 3.6 4.8 6.5 3.9 6.3 4.9 40.0 43.9 47.8 56.6 6.4 8.4 7.9 17.2 16.4 24.0 34.4 35.5 7.8 4.7 14.7 16.7 5.7 3.0 8.9 11.9 57.7 54.1 49.8 41.4 85.8 84.2 87.1 76.7 79.8 72.9 63.8 62.0 85.4 90.6 81.7 78.5 87.8 93.1 84.8 83.2 1.067 1.068 1.065 1.068 1.074 1.075 1.078 1.076 1.067 1.067 1.068 1.067 1.085 1.083 1.084 1.081 1.061 1.061 1.062 1.062 SOIL FERTILITY RESEARCH WITH POTATOES M. L. Vitosh Department of Crop and Soil Sciences Five long term soil fertility experiments were initiated in 1967 when the Montcalm Experimental Farm was established. The zinc experiment was dropped from the study in 1970. Although there have been slight modifica­ tions over the years, this year’s data represents the sixth and final year of these experiments. The soil type at the Montcalm Experiment Farm has been classified as either McBride or Montcalm sandy loam. A detailed examination of the area, shows small scattered areas of other soil types. Since these small areas cannot be managed separately, no attempt has been made to make any adjust­ ments for the variable soil type. Nevertheless the variability in soil type is responsible for some of the yield variation and may explain why some experiments require a rather large difference in yield for treatment diff­ erences to become statistically significant. A fertilizer materials study conducted in 1971 was repeated this year. The soil test data and cultural practices are given at the bottom of Tables 1, 4, 7, 10 and 12. The potato yields obtained in 1972 were the largest recorded for these experiments since their initiation. Source, Rate, and Time of Nitrogen Application This experiment was established in 1967 on three different areas so that a three year rotation could be implemented. In 1969 and 1970, potatoes were preceded in the rotation by sweet corn. The last two years potatoes followed dent corn. The experimental design was a split plot with 10 whole plot treat­ ments and two variety sub-plot treatments. The original experiment was modi­ fied in 1970 when several N treatments were changed to obtain yield data for higher N rates and to evaluate sulfur-coated urea, a slow release form of nitrogen. Results of this year’s study are presented in Table 1. Total yields for both varieties were more than doubled with 60 lb N/A as sulfur-coated urea (SCU) broadcast and plowed down prior to planting plus 60 lb N/A banded at planting. Yield increases beyond the 120 lb rate were not significant but some general trends were noted. Sidedress N generally gave larger yields than broadcast N. Broadcast applications on sandy soils prior to planting are generally inferior due to greater leaching losses. Leaching losses this past year were minimal due to a dry period immediately after planting. Sulfur- coated urea applied at the 120 lb N/A yielded slightly less than an equivalent amount of urea N, however, the opposite trend was observed when 180 lb N/A (SCU) was broadcast and plowed down. Maximum yield for both varieties was obtained with 60 lb N/A banded and 180 lb N/A sidedressed June 16 just prior to killing. Specific gravity of the tubers was slightly reduced by the highest N rates. Previous yields at this location have not shown this decline, however many other investigators have shown that an excess of N can cause low specific gravity. A summary of the data since 1970 (Table 2) shows that the Russet Burbank variety requires slightly higher rates of N fertilizer, when compared to other varieties, to obtain maximum yields. This is indicated by the lower relative yield of Russet Burbanks for the first two treatments (39% vs 41% and 85% vs 91% for Russet Burbank and Sebago, respectively). Slightly better yields of Russet Burbanks were obtained with sidedress N compared to broadcast N prior to planting. No differences due to time of application were found with the Sebago variety. Leaching losses were minimal the past three years under this system of management and did not appear to be a factor when more than 180 lb N/A was used. Sulfur-coated urea did not show any superior qualities as a source of N. Rates of less than 120 lb N/A (SCU) may be more efficient but yields would not be optimum. The four year average for specific gravity was not appreciably affected by any of the N treatments. Potato petiole analysis for 1972 (Table 3) shows that the concentrations of Mg, Fe, Cu, Ba, Mn, Al and B were significantly affected by the N treatments. The N content was not significantly affected but higher rates of N generally gave higher N contents. Based on the last three years data, potato petioles should contain at least 2.7% N at 45-50 days after plant emergence and more than 2.3% N at 50-60 days after emergence for optimum yields. The K concen­ tration of this year’s petiole samples was extremely high. The values are above the normal detection range and may represent unrealistic values. Magnesium concentrations were considerably lower for treatments 1, 2, and 6 compared to most other treatments. Micronutrient concentrations were slightly higher in samples from the check plot. Higher concentrations of Fe, Al and Mn also tended to be associated with higher rates of N fertilizer. Increased acidity due to higher N rates may increase the uptake of these elements. Potassium-Magnesium Study Three different areas were set up in 1967 to evaluate rate and placement of K with potatoes, red kidney beans and field corn. In 1971 the experiment was changed to include four rates of K with and without Mg. Results of this year’s study are reported in Table 4. Total yield of both potato varieties was significantly increased with the first 60 lb K2O/A. Additional broadcast K resulted in slightly larger yields but not enough to be statistically significant. Larger Russet Burbank yields were accompanied by a larger percentage of medium size tubers (1 7/8 in. up to 10 oz) and fewer small tubers (less than 1 7/8 in. diameter). Larger yields of Sebago were primarily due to larger tubers especially those over 3 1/4 in. diameter. Magnesium fertilizer did not affect potato yield at any of the K rates. Specific gravity decreased with increasing rates of K. A decrease of .01 was obtained with 480 lb K2O/A for both varieties. A summary of the past two year’s data (Table 5) shows that maximum yields were obtained with 60 lb K2O/A plowed down and 60 lb K2O banded at planting. Higher and lower rates generally resulted in less than maximum yields. The use of Mg was not beneficial with regard to yields or specific gravity. Specific gravity of both varieties has decreased at a rate of .001 per 50 lb K2O when more than 180 lb K2O/A has been applied. Potato petiole analysis (Table 6) indicates that K, Ca, Mg, Al, Ba and B concentrations in the petioles were significantly affected by the K-Mg treatments. Potassium values are extremely high and may not be accurate because they are above the normal detection range for spectrographic analysis. Variations between samples, however, are expected to be real. Increasing rates of K resulted in higher concentrations of K and lower Ca and Mg. Magnesium fertilizer had the greatest influence on the Mg content of petioles at the lowest rates of K fertilizer. Increasing K fertilizer tended to lower the Al and B content while Ba was most closely associated with uptake of Mg. High uptake of Mg at low rates of K where Mg fertilizer was applied was related to decreased uptake of Ba. Potassium Carrier Study This experiment was initiated in 1967. It was discovered in 1969 and 1970 that potassium-magnesium sulfate was used in place of potassium sulfate. The data for this treatment in 1969 and 1970 should be ignored because the rate of K applied was not equal to that of the other sources. Results of this year’s study are shown in Table 7. Total yields were in­ creased with all sources of K, especially for the Sebago variety. Potassium sulfate resulted in the largest yields for both varieties. Potassium chloride (muriate of potash) resulted in a lower percentage of Russet Burbank tubers over 10 oz. Specific gravity of the Russet Burbank variety was slightly lower in the potassium sulfate plots than all other sources. Potassium chloride gave the lowest specific gravity for the Sebago variety. A four year summary is in Table 8. The four year averages show little or no effect of potassium sources on yield and specific gravity. All sources of K are equal. Potato petiole analysis (Table 9) indicates that K, Ca, Mg, Al, Ba and Mn were significantly affected by the fertilizer treatments in 1972. All sources of K increased the K content and lowered Ca and Mg. Potassium nitrate caused the greatest decrease in Ca, Mg, Al and Mn content. Potassium sulfate accounted for the lowest Ba content while potassium chloride gave the highest Mn concen­ trations. Nitrogen Carrier Study The objective of this study was to evaluate five sources of N on yield and quality of potatoes. Prior to 1971 the N fertilizers were either applied as half plow down and half banded on all just prior to emergence. In 1971 and 1972, 20 lb N/A (ammonium nitrate) was banded on all treatments to eliminate early growth differences due to fertilizer placement. All sources except anhydrous ammonia were topdressed prior to emergence. Anhydrous ammonia was knifed in the same day. Results of this year's study are reported in Table 10. A significant treatment by variety interaction occurred. Calcium nitrate resulted in a lower yield of Russet Burbank potatoes while ammonium sulfate and anhydrous ammonia gave lower yields for the Sebago variety. Anhydrous ammonia accounted for slightly lower specific gravity in the Russet Burbank variety. The nitrate sources (calcium nitrate and ammonium nitrate) had less effect on specific gravity of the Sebago variety than the ammonium sources. The five year average shown in Table 11 indicates that calcium nitrate has been inferior for Russet Burbank. The fact that Russet Burbanks have a higher N requirement and that more N may have been leached from calcium nitrate plots than from the other N sources, may explain this interaction. Anhydrous ammonia has proven to be an excellent source of N fertilizer when applied pre­ plant or sidedress. The five year average for specific gravity indicates that Russet Burbanks were not affected by the N sources while the nitrate sources reduced the specific gravity of the Sebago variety the most. Fertilizer Materials Study The fertilizer materials used in this study were liquid 10-34-0, an ammonium polyphosphate, 8-24-0, an ammonium ortho-phosphate, a 28% N solution, urea, ammonium nitrate, 15-62-0, a granulated ammonium polyphosphate, and 21-53-0, a granulated diammonium ortho-phosphate. Urea, ammonium nitrate and 28% N solution were mixed with the ortho- and polyphosphate materials to obtain a 1-2-0 ratio so that equal rates of N and P could be banded at planting time. The yield, size and specific gravity data are given in Table 12. Total yield and specific gravity were not significantly affected by the treatments. The solid ortho-phosphate treatment had fewer medium size tubers (1 7/8 in. up to 10 oz.) and more off-type tubers compared to the other treatments. The treatments without P tended to yield less than those with P. No differences were observed when the liquid and solid or ortho and polyphosphate averages were compared. All materials were equally effective. TABLE 1. Effects of rate, source and time of nitrogen application on yield, size, and specific gravity of irrigated Russet Burbank and Sebago potatoes Nitrogen application (a) Broad­ castlb N/A n Application (a) Nitroge Band­ ed lb N/A ication (a) Nitrogen Appl (a) Nitrogen Application Russet Burbank over Russet Burbank Total Yield 10 oz% (cwt/A) Side­ dressed lb N/A Russet Burbank Russet Bur bank Less than 1 7/8" 1 7/8" to 10 oz% % Totallb N/A Russet Burbank Off Type % Russet Burbank Sp. Gr. SebagoTotal Yield (cwt/A) Sebago over 3 1/4"% Sebago 1 7/8" to 3 1/4" % Sebago Less than 1 7/8"% Sebago Sp. Gr. 0 0 60 U 60 SCU 60 U 120 U 180 U 60 U 240 U 60 U 60 U 120 SCU Empty table cell60 U 60 U 60 U 60 U 180 SCU 0 0 0 0 0 0 0 0 0 120 U 180 U 240 U 0 120 180 240 300 180 180 240 300 240 LSD (.05) treatmentsw within varieties Empty table cell Empty table cellEmpty table cell LSD (.05) varieties within treatments Empty table cell Empty table cellEmpty table cell 167 408 429 439 430 415 435 449 448 465 56 43 0 5 5 7 6 6 5 9 7 8 4 - 63 80 83 82 81 80 81 78 81 80 6 6 34 11 8 8 9 10 8 8 7 8 5 5 3 4 4 3 4 4 5 5 5 4 1 - 1.081 1.084 1.084 1.081 1.080 1.082 1.082 1.082 1.080 1.080 .004 .003 200 474 483 493 478 467 472 514 497 503 56 43 2 7 8 8 8 5 8 9 10 10 4 - 86 86 85 85 85 87 85 84 83 83 NS 6 11 7 7 7 7 8 7 6 6 6 5 5 1.072 1.069 1.070 1.066 1.068 1.071 1.068 1.068 1.066 1.066 .004 .003 (a) Broadcast urea (U) and sulfur coated urea (SCU) was applied and plowed down two days prior to planting. Banded urea was applied at planting time 2 inches to side and 2 inches below the seed piece. Sidedress urea was applied to soil surface on June 16 prior to hilling. Planted: May 9, 1972 Row spacing: 32 inches Basic fertilizer: 0-150-200 banded at planting time Irrigation: 5.0 inches Soil test: pH = 6.6, P = 278, K = 198 Harvested: Sept. 27, 1972 Seed spacing: Russet Burbank = 14", Sebago = 10" Previous crop: field corn Harvest area: 266 sq. ft. TABLE 2. Summary of yield and specific gravity data for the rate and time of nitrogen application study with potatoes — 1970-72 N Application (a) Broad­ castlb N/A N Application (a) Bande d 1b N/A N Application (a) Side Dressed 1b N/A N Application (a)Total 1b N/A Burbank Average Yield (cwt/A) Russet Russet Burbank Relative Yield (b) (%) Russet Burbank Specifi c Gravity Sebgao Average Yield (cwt/A) Sebago Relative Yield (5) Sebago Specifi c Gravity 0 60 SCU 120 U 180 U 240 U 120 SCU 0 0 0 180 SCU 0 60 U 60 U 60 U 60 U 60 U 60 U 60 U 60 U 60 U 0 0 0 0 0 0 120 U 180 U 240 U 0 0 120 180 240 300 180 180 240 300 240 146 321 347 357 352 340 360 377 359 367 39 85 92 95 93 90 95 100 95 97 1.079 1.080 1.080 1.078 1.079 1.079 1.079 1.080 1.078 1.078 189 419 452 457 453 442 439 458 431 458 41 91 99 100 99 97 96 100 94 100 1.070 1.071 1.072 1.069 1.071 1.071 1.072 1.070 1.069 1.071 (a) Broadcast urea (U) and sulfur coated urea (SCU) was applied and plowed down prior to planting. Banded urea was applied at planting 2 inches to the side and 2 inches below the seed piece. Sidedress urea was surface applied prior to hilling. (b) Expressed as a percent of the maximum yield TABLE 3. Effect of rate, source and time of nitrogen application on the elemental composition of potato petioles. (Russet Burbank and Sebago varieties sampled 7-14-72) Treatment No.(a) 1 2 3 4 5 6 7 8 9 10 LSD (.05) Elements (b) Elements (b) Elements (b) Elements (b) P % N % Elements (b) Elements (b) Ca % K Mg % Fe ppmElements (b) Mn Cu ppmElements (b) Ba ppmElements (b) Alppm Elements (b) Elements (b) Bppm % 17.67 16.85 14.51 16.14 16.02 16.54 15.41 17.76 14.53 15.04 .45 .42 .36 .41 .38 .41 .37 .38 .36 .37 .84 .70 .75 .88 .84 .75 .82 .90 .78 .82 1.9 2.7 3.2 3.3 2.8 2.7 3.2 2.8 3.2 3.2 .40 .56 .77 .92 .78 .61 .74 .80 .74 .80 91 47 25 32 46 39 57 47 29 29 26 22 20 21 20 20 20 22 20 20 ppm 58 84 77 100 117 70 71 91 95 71 87 40 34 37 42 38 38 49 38 34 175 120 120 130 135 115 115 135 120 115 26 21 17 20 20 21 19 21 18 19 NS NS NS NS .22 32 2 10 23 30 3 (a) Treatments are the same as in the previous table. (b) Other elements which were not significantly affected by the treatments in this experiment: Zn and Na. TABLE 4. Effect of rate of potassium and magnesium on yield, size, and specific gravity of irrigated Russet Burbank and Sebago potatoes Potassium-Magnesium (a) Application Broadcast 1b K2O/A Potassium-Magnesium (a) Application Banded 1b K2O/A Potassium-Magnesium (a) Application Broadcas t 1b Mg/A Potassium-Magnesium (a) Application Total 1b K2O/A Russet Burbank Total Yield (cwt/A) Russet Burbank Over 10 oz. % Russet Burbank 1 7/8" to 10 oz. % Russet Burbank Less Than 1 7/8" % Russet BurbankOff Type% 0 0 60 120 180 420 0 60 120 180 0 60 60 60 60 60 60 60 60 60 0 0 0 0 0 0 50 50 50 50 0 60 120 180 240 480 60 120 180 240 334 429 475 452 459 472 424 455 466 447 LSD (.05) treatments within varieties empty table cell empty table cellempty table cell 51 LSD (.05) varieties within treatments empty table cell empty table cell empty table cell 39 2 2 3 4 3 3 3 4 4 3 NS 2 77 82 81 81 80 81 80 81 80 80 3 3 19 12 13 12 13 13 14 11 12 13 3 2 3 4 3 3 4 3 3 3 4 4 1 - Russet Burbank Sp. Gr. 1.080 1.078 1.080 1.080 1.075 1.070 1.080 1.078 1.078 1.078 .005 .005 (a) Potassium and magnesium sources were muriate of potash and epsom salts. Planted: May 9, 1972 Row spacing: 32 inches Basic fertilizer: 60-150-0, 180 lb N/A sidedressed June 17, 1972 Irrigation: 5.0 inches Soil test: pH = 6.4, P = 276, K range = 124-214 Harvested: Sept. 28, 1972 Seed spacing: Russet Burbank = 10", Sebago = 10" Previous crop: Sweet corn Harvest area: 266 sq. ft. Sebag o Total Yield (cwt/A) Sebago over 3 1/4" % Sebag o 1 7/8" to 3 1/4" % Sebago Less than 1 7/8" % 328 433 449 397 422 419 387 447 437 399 51 39 5 7 10 9 8 8 8 9 9 8 3 2 88 87 83 83 84 83 85 85 83 84 3 3 6 6 7 8 8 9 6 7 8 9 3 2 Sebago Sp. Gr. 1.070 1.070 1.070 1.062 1.065 1.060 1.068 1.070 1.060 1.062 .005 .005 TABLE 5. Summary of yield and specific gravity data for the potassium-magnesium study with potatoes 1971-72. Potassium-Magnesium Application (a) Bande Broad­ Application(a) Potassium-Magnesium d cast lb K2O/A lb K2O/A Potassium-Magnesium Application (a) Broad Cast lb Mg/A Potassium-Magnesium Application (a) Total lb K2O/A Burbank Average Yield (cwt/A) Russet Russet Burbank Relative Yield (c) % Russet Burbank Specifi c Gravity Sebago Average Yield (cwt/A) Sebgao Relative Yield (c) % Sebago Specific Gravity 0 0 60 120 180 420 0 60 120 180 0 60 60 60 60 60 60 60 60 60 0 0 0 0 0 0 50 50 50 50 0 60 120 180 240 480 60 120 180 240 326 392 417 394 397 407 370 394 414 396 No Mg average (b)empty table cellempty table cell Mg average (b)empty table cellempty table cell empty table cell 400 empty table cell 394 78 94 100 94 95 98 89 94 99 95 100 98 1.080 1.078 1.078 1.078 1.075 1.070 1.078 1.076 1.076 1.074 1.077 1.076 354 424 436 389 416 414 394 426 428 398 416 411 81 97 100 89 95 95 90 98 98 91 100 99 1.072 1.070 1.069 1.064 1.066 1.061 1.069 1.070 1.064 1.063 1.067 1.066 (a) Potassium and magnesium sources were muriate of potash and epsom salts. (b) Averages are of the four treatments with and without magnesium and having comparable rates of applied potassium. (c) Expressed as a percent of the maximum yield. TABLE 6. Effect of rate of potassium and magnesium on elemental composition of potato petioles. (Russet Burbank and Sebago varieties sampled 7-7-72) Treatment No. (a) N % Elements (b) Elements (b) P % Elements (b) Elements (b) K Ca % Elements (b) Mg % Elements (b) Al ppm Elements (b) Bppm Elements (b) Ba % 7.10 13.11 13.95 18.34 20.08 18.69 13.63 13.29 16.97 22.56 .48 .49 .42 .42 .42 .34 .46 .40 .36 .41 3.4 3.3 3.1 2.8 3.2 3.1 3.4 2.9 3.2 2.9 1 2 3 4 5 6 7 8 9 10 LSD (.05) NS NS 3.6 .84 .80 .62 .72 .63 .54 .74 .62 .58 .59 .11 1.34 1.02 .66 .64 .53 .40 1.13 .81 .57 .54 .19 170 145 120 130 110 100 140 125 120 110 22 ppm 27 30 28 40 39 44 18 22 22 26 9 17 18 16 13 15 12 17 15 15 16 3 (a) Treatments are the same as previous table. (b) Other elements which were not significantly affected by the treatments in this experiment: Na, Cu, Zn, Fe, & Mn. TABLE 7. Effects of different sources of potassium on yield, size, and specific gravity of irrigated Russet Russet Burbank 1 7/8" to 10 oz. % Russet Burbank Less Than 1 7/8" % 81 81 80 79 78 NS 4 6 6 5 7 6 2 1 Russet Burbank Off Type % 3 3 3 3 3 Russet Burbank Sp. Gr. 1.084 1.080 1.080 1.078 1.080 NS .002 - .002 Sebag o Total Yield (cwt/A) Sebago over 3 1/4" % Sebag o 1 7/8" to 3 1/4" % Sebago Less than 1 7/8" % 390 469 474 488 459 47 NS 8 9 9 10 8 NS 85 84 85 85 84 NS 3 4 7 6 6 6 7 NS 1 Sebago Sp. Gr. 1.068 1.062 1.064 1.066 1.065 .002 .002 Burbank and Sebago potatoes Source of Potassium (a) None Potassium Chloride Potassium Nitrate Potassium Sulfate Potassium Carbonate Russet Burbank Total Yield (cwt/A) Russet Burbank over 10 oz. % 422 451 465 471 462 10 9 11 12 13 LSD (.05) treatments within varieties474 LSD (.05) varieties within treatmentsNS3 (a) Applied at a rate of 300 lb K2O per acre broadcast and plowed down prior to planting. Planted: May 9, 1972 Row spacing: 32 inches Basic fertilizer: 120-150-0, 93 lb N/A broadcast and plowed down prior to planting Soil test: pH = 6.2, P = 394, K range = 214-252 Harvested: Oct. 3, 1972 Seed spacing: Burbank = 14", Sebago = 10" Previous crop : Red clover Harvest areas: 266 sq. ft. Irrigation: 5.0 inches TABLE 8. Summary of yield and specific gravity data for the potassium carrier study with potatoes 1967-68 and 1971-72 Source of potassium (a) Russet Burbank Average Yield cwt/A None Potassium chloride Potassium nitrate Potassium sulfate Potassium carbonate 272 298 303 310 302 Russet Burbank Relative Yield (b) % 88 96 98 100 97 Russet Burbank Specifi c Gravity Sebago Average Yield cwt/A Sebago Relative Yield % 1.084 1.081 1.082 1.081 1.081 306 356 356 350 348 86 100 100 98 98 Sebago Specific Gravity 1.072 1.070 1.071 1.071 1.070 (a) applied at rates of 150 lb K2O/A in 1967-68 and 300 lb K2O/A 1971-72 (b) expressed as a percent of the maximum yield TABLE 9. Effect of potassium carriers on elemental composition of potato petioles (Russet Burbank and Sebago Varieties sampled 7-7-72) Treatment No. (a) Elements (b)P Elements (b)N Elements (b) Elements (b) Ca K Elements (b) Mg Elements (b)Al 1 2 3 4 5 LSD (.05) 3.6 3.4 3.7 3.3 3.6 NS .29 .34 .30 .30 .30 NS 7.80 15.84 13.93 13.18 14.44 3.53 1.03 .78 .61 .73 .72 .07 1.50 165 .87 130 .68 110 .92 130 .82 125 .14 11 Elements (b)Ba 63 62 46 22 54 24 Elements (b)Mn 112 114 51 82 67 39 (a) Treatments are same as in previous table. (b) Other elements which were not significantly affected by the treatments in this experiment: Na, Cu, Fe, Zn, B, Mn and Zn. TABLE 10. Effect of different sources of nitrogen on yield, specific gravity and size of irrigated Russet Burbank and Sebago potatoes Source of Nitrogen Russet Burbank over 10 oz % Russet Burbank 1 7/8" to 10 oz. % Russet Burbank Total Yield (cwt/A) Ammonium Sulfate (a) Ammonium Nitrate (a) Calcium Nitrate (a) Urea (a) Anhydrous Ammonia (b) 440 444 408 441 460 6 4 4 5 6 LSD (.05) treatments within varieties 40NS LSD (.05) varieties within treatments322 81 82 83 81 82 NS 3 Russet Burbank less than 1 7/8" % 8 9 9 9 8 NS 2 Russet BurbankOff Type% 5 5 5 6 4 1 - Russet Burbank Sp. Gr. 1.078 1.079 1.078 1.080 1.076 .003 .002 Sebag o Total Yield (cwt/A) Sebago over 3 1/4" % Sebago 1 7/8" to 3 1/4" % Sebago less than 1 7/8" 452 506 496 483 458 40 32 8 7 6 5 8 3 2 86 87 88 88 85 3 3 6 6 6 7 7 NS 2 Sebago Sp. Gr. 1.064 1.067 1.068 1.065 1.065 .003 .002 (a) 180 lb N/A was top dressed May 23, 1972 just prior to emergence (b) 180 lb N/A was knifed in May 23, 1972 just prior to emergence Planted: May 9, 1972 Row spacing: 32 inches Basic fertilizer: 20-150-200, banded 2 inches to side and 2 inches below seed piece Irrigation: 5.0 inches Soil test: pH = 6.6, P = 292, K = 224 Harvested: Oct. 3, 1972 Seed spacing: Russet Burbank = 14", Sebago = 10" Previous crop: Sweet corn Harvest area: 266 sq. ft. TABLE 11. Summary of yield and specific gravity data for the nitrogen carrier study with potatoes 1968-1972 Source of nitrogen (a) Ammonium sulfate Ammonium nitrate Calcium nitrate Urea Anhydrous ammonia Russet Burbank Relative Yield (b) Average Russet Burbank Yield cwt/A % Russet Burbank Specifi c Gravity Sebago Averag e Yield cwt/A Sebago Relative Yield % 325 321 293 321 333 98 96 88 96 100 1.077 1.077 1.077 1.077 1.077 367 379 376 393 383 93 96 96 100 97 Sebago Specific Gravity 1.069 1.071 1.072 1.070 1.070 (a) applied at a rate of 180 lb N/A (b) expressed as a percent of the maximum yield TABLE 12. The effect of liquid, solid, poly and ortho-phosphate fertilizers on yield, size and specific gravity of irrigated Russet Burbank potatoes (Montcalm Experimental Farm). Treatment 1 N (Liquid) 2 N (Solid) 3 N + Poly-P (Liquid) 4 N + Poly-P (Solid) 5 N + Ortho (Liquid) 6 N + Ortho (Solid) LSD (.05) Treatments Rate N-P2O5-K2 O 1b/A Total Yield cwt/A 50-0-0 50-0-0 50-100-0 50-100-0 50-100-0 50-100-0 385 383 409 416 420 405 empty table cell NS empty table cell 405 empty table cell 401 Over 10 oz% 1 7/8" to 10 Less Than 1 7/8" % Off type % Specific Gravity oz. % 2 5 3 5 4 5 NS 3 5 4 4 85 83 85 80 83 79 4 85 81 82 82 7 6 7 8 7 7 NS 7 7 8 7 6 6 5 7 5 9 3 5 7 6 7 1.076 1.080 1.080 1.079 1.080 1.081 NS 1.079 1.080 1.080 1.080 Liquid average (a) Dry average (a) Polyphosphate average (b) empty table cell Orthophosphate average (b)empty table cell 412 412 (a) These are the averages of the three liquid and solid fertilizer treatments. (b) These are the averages of the two poly and ortho-phosphate treatments. Planted: May 8, 1972 Row spacing: 34 inches Broadcast fertilizer: 0-0-180 Sidedress N: 150 lb N/A June 17, 1972 Irrigation: 5.0 inches Soil tests: pH = 5.7, P = 324, K = 228 lb/A Harvested: October 2, 1972 Seed spacing : 14 inches Harvest area: 283 sq. ft. VARIETY STAGE OF GROWTH STUDY IN POTATOES WITH SENCOR-1972 (METRIBUZIN) J. S. Ladlie, W. F. Meggitt and R. C. Bond Department of Crop and Soil Sciences Four varieties of potatoes (709, Onaway, Sebago, Russet Burbank) were planted May 11 on sand clay loam (organic matter 1.2%) Montcalm County, Michigan. The plots were 10 x 47 ft in a randomized complete block design with three replications. The study was divided into two ranges, with two varieties in each range. Two rows of each variety were planted in each plot in the range. 709, Onaway in the east range and Sebago and Russet Burbank in the west range. The study was designed to learn the effect of time of postemergence applications of metribuzin on: crop injury, flowering and row fill, lodging, degree of vine kill, yield, and weed con­ trol on four varieties of potatoes. Three stages of postemergence appli­ cations were used on all four varieties. The height of the potatoes at these stages of postemergence application were: A = 0-4", June 7; B = 4-10", June 16; and C = 14", June 22. The same treatments were applied at A, B and C stages of growth. Preemergence treatments were all applied May 23. Preemergence, postemergence and split applications of preemergence and postemergence were compared in the study. Treatments were applied with a tractor mounted sprayer delivering 23 gpa. Rainfall was .03 inch 10 days after preemergence application. The major weeds present were: pigweed, lambsquarter and barnyard­ grass. Weed heights at the time of postemergence applications were: A = broadleaf 3", grass 3"; B = broadleaf 6-8", grass 5-7"; C = broadleaf 15-24", grass 8-12". Soil surface and air temperatures at the time of postemergence applications were: A = 120°F, 88°F; B = 60°F, 60°F; C = 77°F, 82°F respectively. Crop injury was rated on June 23. Yellowing and necrosis of the leaf margin was evaluated on a 0-10 basis. Preemergence treatments of metribu­ zin gave only slight injury at the 2 lb/A rate. Onaway indicated the most injury with a rating of 13%. In the split applications and postemer­ gence treatments alone only the A and B stages of application were rated. The C stage had been sprayed only the day before the rating and did not justify an evaluation. The B stage of postemergence application created more crop injury than the A stage of the same treatment. This was true for both split applications and the postemergence alone. Again Onaway received the high injury rating of the four potato varieties. Flowering and degree of row fill was rated on July 6. The evaluation was on a 0 to 3 basis with 0 representing good blossoming and rows com­ pletely filled and 3 indicating no blossoms or row not completely filled. Preemergence treatments on all four varieties indicated good blossoming and row fill. The B stage of postemergence application again received the higher ratings. This was followed by C stage and then A stage indicated the least amount of flowering or row fill delay. Of the four varieties of potatoes the Onaway showed the most severe delay in blossoming and row fill. The oil concentrate added to the 1/2 lb/A postemergence treatments in­ creased the ratings only slightly at the C stage of application. This is in comparison with the 1/2 lb/A postemergence without oil concentrate. The degree of lodging and row fill was rated on July 27, 1972. Ratings were made on an 0-3 basis. 0 indicated no lodging and complete row fill and 3, lodging with rows not completely filled. The preemergence treatments of 1/2, 1, and 2 lb/A were about even in the ratings received for all four varieties in comparison to each other. A stage of post­ emergence application again received the lowest rating. C and B stages of application were close in their evaluations with B stage still indicating the high rating in most cases. The four potato varieties showed less difference in the ratings for any given treatment. The 709 or Onaway received the highest ratings for lodging and row fill. The rating for degree of vine killing before the actual vine killing application was made on two separate dates, because of differences in maturity. The 709 and Onaways were rated August 28 and Sebago and Russet Burbanks, September 13. 0 indicated that the vines were all gree and a rating of 10 represented vines completely dead. The preemergence applications had a higher degree of vine kill than the split applications or postemergence applications alone. This would indicate a delay in the amount of vine kill received for postemergence applications at the same rate as preemergence. The A, B, C stages of application showed very little difference with no one stage or rate of herbicide indicating a high degree of vine kill over the other. Differences in varieties in percent of vine kill recorded may be due to the differences in maturity of the four varieties. The no treatment check had a large percentage of vine kill because of the weed pressure. Weed control was rated July 12 on 0-10 basis. Ninety-six percent or more control was obtained on the broadleaf and grass species for all treat­ ments, except the C stage of postemergence application. The potatoes pro­ vided a protective canopy from the postemergence spray for the weeds at the C stage of application. The weeds which were missed are the cause of lower ratings for the C stage. Generally split applications of metribuzin will give you better grass control. Although in this study preemergence treatment gave excellent control of broadleaf and grass species. Rating the stages of postemergence applications as to weed control: A, B and C stage, respectfully with A stage generally giving the best and C the least weed control. The oil concentrate added to the 1/2 lb/A postemergence application did not significantly increase the weed control compared to the treatment without the oil concentrate. For preemergence, postemergence split applications, there was little difference between the three stages in weed control. Split applications would be preferred over single preemergence or postemergence applications. This study brought out several factors to be considered when using metribuzin for weed control on potatoes. Varieties of potatoes do respond differently to applications of metribuzin. Split applications of metribuzin will give more complete and satisfactory weed control. Postemergence applications should be made before the potatoes are 4 inches in height or after they reach a height of 14 inches or more. The B stage of postemergence applications (8 to 10") is at the time of bud formation. This seems to damage and set back the potatoes more at this critical bud formation stage. Postemergence alone at the C stage of application will miss some of the weeds due to the canopy cover at this stage of growth. Although split applications with the post­ emergence application coming at the C stage of growth gave good weed control. The ideal application of metribuzin would be to apply the split application of 1/2 + 1/2 lb/A at the A and C stages. The first treat­ ment would be a preemergence and postemergence application because the weeds would have grown to 1 inch height by this time, then if necessary come back at the C stage with another 1/2 lb/A postemergence. Table 1. Variety Stage of Growth Study in Potatoes with Sencor. Montcalm Co., 1972 Planted: May 11, 1972 Treated: Pre - May 23, 1972 Rated: Stage A Post June 7, 1972 B Post June 16, 1972 Stage C Post June 22, 1972 Stage Variety: 709, Onaway, Sebago, Russet Burbank Soil Type: Sand clay loam Organic Matter: 1.2% Harvest Date: 709 & Onaway, Sept. 6, 1972 Sebago & Russet Burbank, Sept. 21, 1972 Weeds present: pigweed, lambsquarter, barnyard grass Pertinent information: Height of potatoes at the three stages of postemergence application: A = 0-4.0"; B = 8.0 - 10.0"; C = 15.0" Trmt. No. Treatment Crop Crop Injury1 6/23/7 2 Ona. Crop Injury1 6/23/7 2 Seb. Injury16/23/72709 Rate lb/A 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0.0 Sencor - Pre 0.0 1/2 Sencor - Pre 0.0 0.3 1 2 0.3 1.3 Sencor - Pre 1/2 + 1/2 0.0 2.0 A Sencor - Pre & Post B Sencor - Pre & Post 1/2 + 1/2 0.3 3.0 -- -- C Sencor - Pre & Post A Sencor - Pre & Post B Sencor - Pre & Post C Sencor - Pre & Post A Sencor - Post 1/2 + 1/2 1+1 1+1 1+1 1/2 B Sencor - Post C Sencor - Post A Sencor - Post B Sencor - Post C Sencor - Post 1/2 1/2 1 1 1 -- -- -- -- 0.7 2.7 2.7 5.7 1.0 2.7 0.7 3.3 -- 3.7 1.0 2.3 5.0 -- Flowering & Row Fill2 7/6/72709 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.7 0.0 0.0 0.3 0.7 0.0 0.3 0.7 Flowering & Row Flowering & Row Fill2 Fill2 7/6/7 2 Ona. 7/6/72 Seb. 0.0 0.0 0.0 0.0 1.3 0.3 0.7 2.7 2.0 0.0 1.3 1.3 1.7 3.0 2.0 0.0 0.0 0.0 0.0 0.3 0.0 0.0 1.0 0.7 0.0 1.0 0.0 0.3 1.7 0.7 Flowering & Row Fill2 Lodging & Row Fill3 7/6/72 R.B. 0.0 0.0 0.0 0.0 1.3 0.7 1.3 2.3 1.0 0.0 1.3 1.0 0.3 2.3 0.7 7/27/72709 1.3 1.7 1.3 0.7 1.0 0.7 0.3 0.7 1.3 1.0 1.3 0.7 1.3 1.7 0.7 Lodging Lodging & Row Fill3 7/27/7 2 Ona. Lodging & Row Fill3 7/27/7 2 Seb. & Row Fill37/27/72 R.B. 1.0 1.3 1.3 0.3 1.3 1.0 0.3 1.0 0.7 0.7 1.3 0.3 0.7 1.7 0.3 1.0 1.0 0.7 0.3 1.0 0.3 1.0 0.7 0.7 0.7 1.0 1.0 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.0 0.3 0.3 0.0 0.3 0.3 0.3 1.3 0.3 0.3 0.3 Crop Injury16/23/72 R.B. 0.0 0.0 0.0 1.0 1.7 -- 1.0 4.0 1.0 1.7 1.0 2.7 -- -- -- 0.0 0.0 0.3 1.3 1.3 -- 1.3 3.7 -- 1.3 1.7 -- 1.0 3.7 -- Table 1 Continued Trmt. No. Treatment Rate lb/A Crop Injury16/23/72709 Crop Injury1 6/23/7 2 Ona. Crop Injury1 6/23/7 2 Seb. 16 17 18 19 20 A Sencor+Oil Conc.-Post B Sencor+Oil Conc.-Post C Sencor+Oil Conc.-Post Check - weed free Check - no treatment 1/2+1 qt 1.3 3.7 1/2+1 qt 1.7 4.0 1/2+1 qt -- -- -- 0.0 0.0 -- 0.0 0.0 0.7 1.3 -- 0.0 0.0 Flowering & Row Fill2 7/6/72 709 0.0 0.3 0.7 0.7 0.0 Flowering & Row Flowering & Row Fill2 Fill2 7/6/7 2 Ona. 7/6/72 Seb. 0.0 1.3 2.0 0.7 0.0 0.0 1.0 1.3 0.0 0.0 Flowering & Row Lodging & Row Fill3 Fill27/6/72R.B. 0.0 1.3 1.3 0.3 0.0 7/27/72709 0.7 0.3 1.7 0.0 0.0 Lodging & Row Fill3 7/27/72 Ona. Lodging & Row Fill3 7/27/7 2 Seb. 0.3 0.3 1.7 0.0 0.0 0.7 1.0 0.7 0.0 0.0 Lodging & Row Fill37/27/72R.B. 0.3 0.7 0.3 0.0 0.0 Crop Injury16/23/72 R.B. 0.7 1.3 -- 0.0 0.0 1 Rated June 23, 1972 for crop injury and weed control - 0 - No injury; 10 - Complete kill/complete control 2 Rated July 6, 1972 - 0 = good blossoming and rows filled; 3 = no blossoms and rows not filled 3 Rated July 27, 1972 - Rated on: Degree of lodging and row fill 0 = no lodging and complete row fill; 3 - lodging and rows not complete filled Table 1. Continued Trmt. No. Treatment Sencor - Pre Sencor - Pre Sencor - Pre A Sencor - Pre & Post B Sencor - Pre & Post C Sencor - Pre & Post A Sencor - Pre & Post B Sencor - Pre & Post C Sencor - Pre & Post A Sencor - Post B Sencor - Post C Sencor - Post A Sencor - Post B Sencor - Post C Sencor - Post Rate lb/A 1/2 1 2 1/2 + 1/2 1/2 + 1/2 1/2 + 1/2 1+1 1+1 1+1 1/2 1/2 1/2 1 1 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 of 4 Degree of4 Degree Vine Kill Ona. Degree Of4 Vine Kill Seb. Vine Kill709 Weed Control Evaluations5 Bd. Lv. Weed Control Evaluations5 Grass Degree Of4 Vine KillR.B. 4.7 8.3 3.7 7.3 5.3 8.7 3.7 6.0 3.3 6.0 2.7 6.0 2.7 5.3 2.7 4.7 3.0 6.3 3.7 6.3 4.7 6.3 7.0 3.7 3.7 6.0 2.7 4.0 3.0 5.7 3.0 5.7 3.7 6.0 7.0 4.0 6.3 7.0 9.7 9.7 5.0 5.7 5.7 6.3 5.3 5.0 4.7 3.7 4.7 4.0 4.0 4.0 5.3 4.7 4.3 5.0 4.0 4.3 4.0 7.3 4.3 5.0 5.3 5.0 4.7 4.3 4.7 3.7 3.7 3.7 4.0 3.3 4.3 3.0 3.3 4.0 4.0 4.0 4.0 7.7 9.7 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 9.8 8.0 10.0 9.8 8.3 10.0 10.0 8.0 10.0 0.0 9.7 10.0 10.0 9.7 10.0 9.8 10.0 10.0 10.0 9.6 9.6 9.6 10.0 10.0 9.8 9.8 9.7 8.8 10.0 0.0 A Sencor+Oil Conc.-Post 1/2 +1 qt B Sencor+Oil Conc.-Post 1/2 +1 qt 1/2 +1 qt C Sencor+Oil Conc.-Post - Check - weed free - Check - no treatment 4Rated for degree of vine killing before actual vine killing application. Vine kill evaluation dates: 709 and Onaway, August 28; Sebago and Russet Burbanks, Sept. 13, 1972 0 - Vines all green; 10 - vines completely dead 5Rated July 12, 1972 — 0 - No control; 10 - Complete control Weed Control Evaluations in Potatoes on Mineral Soil J. S. Ladlie, W. F. Meggitt and R. C. Bond Russet Burbank potatoes were planted May 11 on a sandy clay loam (organic matter 1.2%), Montcalm County, Michigan. The plots were 10 x 50 ft in a randomized complete block design with three replications. The preemergence treatments were applied May 23 and the postemergence treatments June 7. Treatments were applied with a tractor mounted sprayer delivering 23 gpa. Rainfall was .03 inch on the sandy clay loam within 10 days after application. The surface temperature at the time of post­ emergence application was 120°F and the air temperature 88°F. The Russet Burbank potatoes were 4-6 inches with the broadleafs and grass being 3-4 inches in height at the time of postemergence application. The major weeds present were pigweed, lambsquarter, barnyard grass and crabgrass. The plots were visually rated on June 23. The preemergence and postemergence herbicide treatments all gave 90% or more control of the broadleaf weeds except: U-27, 267, 3 and 4 lb/A and Gulf S-6044, 2 lb/A. The control of grass was 80% or more for all treatments with the exception of these treatments: metribuzin 1/2 lb/A; U-27, 267, 3 and 4 lb/A and Gulf S-6044. The best overall preemergence treatments were linuron, 2 lb/A; chlorobromuran, 2 lb/A; alachlor + dino­ seb, 2 + 4 1/2 lb/A; metribuzin, 1 lb/A and metribuzin + alachlor, 1/2 + 2 lb/A, all of which controlled 89-100% of both the broadleaf and grass species. Metribuzin gives satisfactory broadleaf weed control at 1/2 lb/A, but is weak on grass with only a preemergence application. Metribuzin as a split preemergence and postemergence treatment at 1/2, 3/4 lb/A pre­ emergence and 1/2, 3/4 lb/A postemergence controlled 98-100% of the total weed population. Oil or oil concentrates added to the postemergence treat­ ments of metribuzin did increase the grass control received. Crop injury was not at a high enough level on any of the treatment to cause concern. Table 2. Preemergence and Postemergence Weed Control Evaluations in Potatoes on Mineral Soil, Montcalm Co., 1972. Planted: May 11, 1972 Treated: Pre - May 23, 1972; Post - June 7, 1972 Rated: June 23, 1972 Weeds present: lambsquarter, pigweed, barnyard grass, crabgrass Variety: Burbanks Soil Type: Sandy clay loam Organic Matter: 1.21% Rate lb/A INJURY Burbanks Weed Control Rating Bd. Lv. Weed Control Rating Grasses Trmt. No. PRE Treatment Rate lb/A PRE Trmt. Lorox Patoran Maloran 1 2 3 4 X Lasso 5 Sencor 2 2 2 2 1/2 POST Rate lb/A Trmt. empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell 4 1/2 empty table cell empty table cell empty table cell empty table cell empty table cell empty table cellSencor empty table cellSencor empty table cellSencor empty table cellSencor empty table cellSencor empty table cellSencore+Oil Conc. empty table cellSencor+Oil Conc. empty table cellSencor+Oil empty table cellSencor+Oil empty table cell empty table cell empty table cell DNBP 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 empty table cell empty table cell 0.0 empty table cell 0.0 empty table cell 0.7 empty table cell 0.7 empty table cell 0.0 empty table cell 0.0 1.0 0.3 1.3 2.0 1/2 1/4 3/4 1/2 2.0 1 1.7 1/2 + 1 qt 1/2 + 1 qt 1.3 1/2 + 1 gal 1.3 1/2 + 1 gal 0.7 6 7 8 9 10 11 12 13 14 15 Sencor Sencor Sencor Sencor 1 1/2 3/4 3/4 empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell empty table cell Sencor 1/2 Sencor 1/2 10.0 9.9 10.0 9.7 9.8 9.8 10.0 10.0 10.0 10.0 10.0 9.8 10.0 9.7 10.0 10.0 0.7 0.0 6.0 10.0 9.8 8.0 9.0 9.0 7.2 8.9 9.8 9.0 9.9 8.3 9.2 8.3 9.8 8.2 10.0 8.9 0.0 0.0 7.5 9.8 U-27, 267 Gulf S-6044 Lasso U-27, 267 1/2 3 4 Gulf S-6044 2 4 16 X Sencor 17 18 19 20 0 - No injury and no control; 10 - Complete control or kill X = Tank mix empty table cell empty table cell empty table cell empty table cell 2 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 0.0 empty table cell 0.0 empty table cell0.0 empty table cell 0.7 empty table cell0.0 Vine Killing Evaluation in Potatoes in 1972 J. S. Ladlie, W. F. Meggitt, R. W. Chase and R.C. Bond Postemergence vine killing treatments were applied to Russet Burbank potatoes in Montcalm County, Michigan. The potatoes were planted May 11, with the treatments being applied September 15. The treatments were evaluated on September 21. The plots were 10' by 30' in a randomized complete block design with three replications. Treatments were applied with a tractor mounted sprayer using flood nozzels delivering 50 gpa. The air temperature at the time of application was 70°F. Des-I-Cate, 1 1/2 gal and Des-I-Cate + oil, 1 1/2 + 1 gal/A gave 100% vine kill. Paraquat + X-77, 2 pts + 1 pt/A remained high on the list of effective vine killing compounds with 97% vine kill. The remaining treatments were below 90% with exception of Dinoseb, 2 pts with 90% vine kill. Dinoseb at 1 1/2 pts/A gave 73% vine kill with a slight increase in the amount of vine kill with one of these adjuvants. Oil, 1 gal; Agri-Oil Plus, 1 pt; Fomex, 1 qt; Fomark, 1 qt; and X-77, 1 pt. All of the adjuvants listed were about equal in increasing phytotoxicity of Dinoseb. Table 3. Vine Killing Evaluations in Potatoes, Montcalm Co., 1972. Planted: May 11, 1972 Treated: September 15, 1972 Rated: September 21, 1972 Variety: Russet Burbanks Soil Type: Sandy clay loam Organic Matter: 1.21% Air Temp.: 70°F Trmt. No. Treatment Rate lb/A Vine Kill Sept. 21, 1972 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Des-I-Cate Des-I-Cate + Oil Evik Evik + Oil Evik + Oil 1 1/2 gal 1 1/2 gal + 1 gal 2.4 lbs 2.4 lbs + 1 gal 2.0 lbs + 1 gal Paraquat + X-77 General General + Oil General + Agri-Oil Plus General + Fomex 2 pts + 1 pt 1 1/2 qt 1 1/2 qt + 1 gal 1 1/2 qt + 1 qt 1 1/2 qt + 1 qt General + Fomark General + X-77 General Premerge Check 1 1/2 qt + 1 qt 1 1/2 qt + 1 pt 2 qt 4 qts --- 0 - No vine killing; 10 - Complete vine killing 10.0 10.0 8.0 7.7 7.0 9.7 7.3 8.7 8.7 8.2 8.0 8.3 9.0 8.7 5.0 INSECTICIDE EVALUATION FOR PEST MANAGEMENT OF POTATOES Arthur L. Wells, Department of Entomology The entomological research on potatoes at the Montcalm Experimental Farm consisted of the evaluation of several new insecticides for potential use in the management of foliar insects. These consisted of fifteen treatments using soil systemics and seven treatments using foliar applications compared to untreated check plots. An additional study was conducted at the Muck Experimental Farm to evaluate certain combinations of systemic and foliar insecticides of potatoes. A brief report on the demonstration plots at the Meyer farm in Bay County is also included. A. Evaluation of Soil Systemic and Foliar Insecticides Procedure Six soil systemic insecticides applied alone or in combinations with other materials were evaluated for their effectiveness in potato insect control programs. These were applied in row with the seed or in a band each side and below the seed (Split Band) at the time of planting. Prior to hilling on June 15 certain treatments received an additional sidedressed application of three different materials. Russet Burbank and Norchip seed planted at 12 inch spacings were used in the study. The plots consisted of three replications of four 50 foot rows (two rows of each variety). Two replicated untreated plots were included in the study for comparison. A recommended fertilizer, herbicide and fungicide program was followed in all plots. Seven foliar insecticides and an untreated check were compared on an adjacent range for their value against potato insects. The plot layout and agronomic practices were the same as in the systemic study except that these received foliar applications only. The applications were made with a CO2 powered sprayer delivering 80 gallons per acre on June 26, July 21, August 10 and 22. Insect populations were evaluated on July 11, 21, August 10 and 30 by either sampling the leaves of each variety or with an insect net (10 sweeps per plot). The list of treatments and insect data from the plots are summarized in Table 1. The inside row of each variety on all the plots were harvested on September 19-22 and yield and size distribution of the tubers were determined. Specific gravities of the tubers from each plot were taken approximately six weeks after harvest. These data are presented in Table 2. Results The cool temperatures and adequate rainfall during the early part of the growing season was ideal for activating the systemic insecticides. This is reflected by the almost complete protection from flea beetles and potato leaf­ hopper populations. The same conditions which resulted in movement of the systemic treatments into the foliage acted as a deterrant for early aphid migration and establishment in the plots during the period of evaluation. The sidedressing applications did not increase the insecticidal protection afforded by the planting time treatments. The foliar treatments were not adequately timed to evaluate against the second brood flea beetles (the last week of July) however the early treatments were effective against leafhoppers. It is very difficult to evaluate such low populations of aphids with a sweep net. Cutworm damage to the Norchip tubers were noted at harvest with less than one percent of the tubers (by weight) being damaged in any of the plots. The damage to the Burbanks was too low to evaluate. All of the insecticide treatments gave higher yields than did the adjacent untreated plots. The differences were greater in the longer season Burbanks Table 1. The effects of soil systemic and foliar insecticides on foliar insect populations Material and Formulation Lbs. Tox./A. Place­ ment* Potato Flea Beetles July11 Soil Systemics Soil Systemics Soil Systemics Soil Systemics Soil Systemics Soil Systemics Soil Systemics Soil Systemics Soil Systemics Potato Flea Beetles July Potato Leafhopper Adults/30 sweeps Jul Potato Leafhopper Potato Potato Leafhopper Nymphs/9 Flea Beetles Aug leaves 10 Norc y 11 Nymphs/9 leavesBurb Soil Systemics Soil Systemics Soil Systemics 0 1 0 5 21 Soil Systemics Potato Leafhopper Adults/30 sweeps July 21 Potato LeafhopperAdults/30 sweeps Au g 10 Aphids Aphids Au g AphidsAu g 30 10 Aphid July21 sJuly11 Soil Systemics 1 1 4 1 1 1 0 8 4 3 2 6 6 2 1 1 0 0 1 0 0 1 0 2 0 4 5 6 8 5 0 3 3 26 30 10 12 3 5 10 16 10 4 3 4 6 52 51 9 35 7 5 23 21 11 5 8 2 5 9 30 4 25 13 4 75 73 64 73 48 48 17 27 48 55 65 45 67 0 0 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 2 0 2 1 3 5 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 1 0 1 0 1 3 0 Split B Split B Side Dr Split B Split B Side Dr In-row In-row In-row In-row In-row Side Dr In-row Side Dr In-row In-row In-row Side Dr In-row Side Dr Soil Systemics Amer Cy 92100 15% Gran Amer Cy 92100 15% Gran Thimet 15% Gran Thimet 15% Gran + Am Cy 92100 15% Gran Di Sham 15647 10% Gran Di Sham 15647 10% Gran Temik 10% Gran Furadan 10% Gran Furadan 10% Gran Furadan 10% Gran + Disyston 15% Gran Furadan 4 Flow Disyston 15% Gran Disyston 15% Gran Disyston 15% Gran Untreated Foliars Meta-Systox-R & SC Thiodan 2 EC Lannate 90 WDP Monitor 4 SC Furadan 4 Flow Azodrin 3.2 EC Zolone 3 EC Untreated 3 lb 3 lb + 2 lb 3 lb 3 lb 2 lb 1 1/2 lb 3 lb 3 lb 3 lb 3 lb + 2 lb 3 lb 2 lb 3 lb 3 lb 3 lb + 2 lb 3 lb + 3 lb — Foliars 1/2 lb 1/2 lb 1/2 lb 1/2 lb 1/2 lb .8 lb 3/4 lb — 1 0 1 6 4 4 5 3 0 3 3 2 0 0 0 0 0 0 0 0 0 0 0 0 0 65 Foliars 0 1 4 0 0 0 0 53 — Foliars Empty table cell Empty table cell Empty table cell Empty table cell Empty table cell Empty table cell Empty table cell Empty table cell 0 3 0 40 8 170 Foliars Foliars Foliars 142 301 306 350 258 245 302 278 10 5 4 2 4 10 5 10 0 0 0 0 0 0 0 0 0 56 6 29 9 402 1 13 1 32 1 80 0 26 82 82 Foliars Foliars Foliars Foliars FoliarsFoliars Foliars Foliars 0 0 5 0 0 0 0 36 2 8 5 9 4 4 3 14 4 56 84 48 24 18 35 359 1 10 9 24 11 14 10 16 2 0 4 2 8 3 1 7 17 26 49 18 122 6 17 162 3 24 27 34 31 17 36 15 48 29 44 44 57 63 49 73 * Soil treatments based on 34" rows (15,390 row-ft./A.); In-row—applied in 4" band on seed; Split band— applied in band below and each side of seed; Sidedress—applied on side of plant rows on June 15 prior to hilling; Foliars—applied in water with CO2 sprayer at 80 gal/A. on June 26, July 20, Aug. 10 and 22, 1972. ** Numbers per 30 sweeps. Table 2. The effects of soil systemic and foliar insecticides on potato yield, size and specific gravity. Soil Systemics Soil SystemicsSoil SystemicsSoil Systemics Soil SystemicsSoil SystemicsSoil Systemics Material & Formulation Lbs. Tox./A. Place­ ment / A wt C p hi c Nor Soil Systemics Amer Cy 92100 15% Gran Amer Cy 92100 15% Gran Thimet 15% Gran Thimet 15% Gran + Am Cy 92100 15% Gran Di Sham 15647 10% Gran Di Sham 15647 10% Gran Temik 10% Gran Furadan 10% Gran Furadan 10% Gran Furadan 10% Gran + Disyston 15% Gran Furadan 4 Flow Disyston 15% Gran Disyston 15% Gran Disyston 15% Gran Untreated Foliars Meta-Syston-R 2SC Thiodan 2 EC Lannate 90 WDP Monitor 4 SC Furadan 4 Flow Azodrin 3.2 EC Zolone 3EC Untreated 1 1/2 lb 3 lb 3 lb + 2 lb 3 lb 3 lb 2 lb 3 lb 3 lb 3 lb 3 lb + 2 lb 3 lb 2 lb 3 lb 3 lb 3 lb + 2 lb 3 lb + 3 lb — Foliars 1/2 lb 1/2 lb 1/2 lb 1/2 lb 1/2 lb .8 lb 3/4 lb — 362 364 356 329 355 338 373 379 364 353 364 345 350 Split B Split B Side Dr Split B Split B Side Dr In-row In-row In-row In-row In-row Side Dr In-row Side Dr In-row In-row In-row Side Dr In-row Side Dr 338 — 263 Foliars Foliars Empty table cell 352 Empty table cell 349 Empty table cell 361 Empty table cell 342 Empty table cell 352 Empty table cell 321 Empty table cell 340 Empty table cell 285 Norchip 1 e z i " 4 / 1 S 3 7/8" 1 o t e z i s p i h c r o N + " 4 1/ 3 e z Si o t " 8 / 7 p i h c r o N Soil Systemics Gr. Sp. p hi c Nor Soil Systemics 7% 87% 6% 1.076 6 7 6 7 6 7 6 6 6 6 8 6 87 88 89 86 86 85 90 86 89 89 87 89 7 5 5 7 8 8 4 8 5 5 5 5 1.076 1.075 1.076 1.077 1.075 1.074 1.076 1.075 1.077 1.077 1.076 1.077 90 88 6 10 FoliarsFoliars FoliarsFoliars 1.078 1.073 4 2 9 9 8 8 10 9 7 15 88 89 89 89 86 88 90 85 3 2 3 3 4 3 3 - 1.075 1.077 1.074 1.076 1.074 1.077 1.075 1.073 Russet Burbank Cwt./A. 504 515 462 421 460 428 491 453 474 463 495 456 457 437 309 Foliars 440 448 436 445 438 436 435 355 Russet + e z i Off-Type Russet k . S n e z i S k n a b r u B " 4 / 1 3 o t " 8 / 7 1 r a b z o Russet Burbank Size to 1 7/8" k n a b r u B B Soil Systemics 6% t e s s u R Soil Systemics 7% 76% 11% 1 0 u Russet Burbank Sp. Gr. Soil Systemics Soil Systemics 1.082 8 6 7 9 8 7 9 8 9 8 8 6 75 80 74 74 78 76 77 76 74 72 80 80 10 9 9 10 8 10 8 7 9 10 9 10 7 5 10 6 6 7 6 9 8 10 3 4 1.081 1.081 1.082 1.082 1.082 1.082 1.082 1.079 1.081 1.079 1.083 1.085 4 4 8 4 82 80 1.085 1.077 6 12 FoliarsFoliars Foliars Foliars Foliars 11 10 9 9 8 9 10 12 1.079 1.080 1.078 1.079 1.078 1.080 1.077 1.075 9 7 12 8 9 9 9 7 10 12 8 11 14 10 7 6 70 71 71 72 69 72 74 75 than in the Norchips. The high percentage of Size A tubers (1 7/8" and up) could be attributed to the excellent growing conditions through the growing season. The specific gravities of the tubers from the treated plots of both varieties appear higher than the untreated controls. B. Insecticide Evaluation at the Muck Experimental Farm Procedure Eight treatments including a soil systemic alone or in combination with foliar insecticides were evaluated for the control of foliar feeding insects. The treatments were randomized in three replications of paired 25 foot rows using whole Sebago seed. The plots were plnated on May 19 with the soil systemic applied in the row with the seed and the foliars applied with a CO2 powered sprayer. Two plots received a sidedress application of Disyston granules on June 27. Foliar applications were made on July 6, 20, August 10 and 29. Insect populations were sampled on July 6, 20, August 9, 17, 29, September 1 and 5 and are summarized in Table 3. Yields and size distribution of the tubers were determined at harvest on October 19. The data along with the specific gravities of each tuber sample are presented in Table 4. Results The heavy rainfall and cool temperatures early in the growing season resulted in excellent vine growth and thus made it difficult to evaluate insect numbers. The specificity of Dipel toward insects other than those evaluated is apparent. This bacterial insecticide is most effective against cabbage insects which were also studied in adjacent plots. Pirimor, which is specific on green peach aphids, also did not affect the other insects. The effectiveness of the double application of Disyston on muck soils is shown on aphids as well as potato beetles and would probably look better against the other insects if the plots had been larger and thus had less migration between centers of plots. Table 3. Summary of Foliar Insects on Plots at Muck Experimental Farm. Material and Formulation Lb. Tox/A. Place­ ment Dipel WP Disyston 15% Gran Disyston 15% Gran Disyston 15% Gran + Meta-Systox-R 2 SC Pirimor 50% WP Thiodan 2 EC Thiodan 2 EC + Fomark Untreated 1/2 lb 3 lb 3 lb + 3 lb 3 lb + 3 lb 1/2 lb 1/4 lb 1/2 lb 1/2 lb 1 qt — Fol Band Band Side Band Side Fol Fol Fol Fol Fol — f a e l o t a t o P . ) 5 pt e S - 5 y ul J ( s p e we S 0 3 / s ct e s n I al ot T 643 367 318 308 559 348 363 481 Total Insects/ 30 Sweeps (July 5-Sept. 5) Potato Flea Beetles 687 586 606 667 815 750 500 712 hoppers o . at l o ot P C Total s p e e w S 0 3 / s t c e s n I ) 5 . t p e S - 5 y l u J ( beetles l a ot T . ds hi 5) Ap pt Se 5- y ul J ( ps e we S 0 3 s/ ct e ns I 193 111 40 34 108 2 4 102 414 80 132 55 71 189 164 340 al ot T Lygus Bugs Insects/30 Sweeps (July 5- Sept. 5) 223 240 216 131 154 206 128 206 Total Insects/30 Sweeps (July 5- Sept. Parasites & Predators 5) 18 36 19 19 25 30 32 32 Table 4. Yield, Size and Specific Gravity from Plots at Muck Experimental Farm. Empty table cellEmpty table cell Material and Formulation Dipel WP Disyston 15% Gran Disyston 15% Gran Disyston 15% Gran + Meta-Systox-R 2 SC Pirimor 50 WP Thiodan 2 EC Thiodan 2 EC + Fomark Untreated 1/2 lb 3 lb 3 lb + 3 lb 3 lb + 3 lb 1/2 lb 1/2 lb 1/2 lb 1/2 lb 1 qt — Fol Band Band Side Band Side Fol Fol Fol Fol — Yield/A. cwt. 360 391 Yield/A. bu. 600 652 % Size Distribution * 8% 7 % Size Specific Distribution ** % Size Distribution *** Gravity 24% 1.060 1.063 25 68% 68 384 640 385 399 400 364 342 642 665 667 607 570 7 7 8 8 8 8 67 68 70 62 62 67 26 25 22 30 30 25 1.059 1.061 1.059 1.063 1.062 1.062 * = up to 1 7/8 **=1 7/8 - 3 1/4 *** = greater than 3 1/4 All of the effective materials provided higher yields than the untreated check. There appeared to be no differences between the specific gravities of any of the treatments. C. Yields from the Demonstration Plots in Bay County The results of the demonstration plots at the Meyer Farm in Bay County are summarized here. The four row plots using Norchip variety were planted on April 28 with either Thimet or Disyston banded with the fertilizer at 2.2 lbs. toxicant per acre. One of the Disyston treated plots received an additional application sidedressed at the time of hilling on June 7. One each of the Thimet and Disyston treated plots received foliar applications of insecticides as well as fungicides during the season. A four row untreated plot was left for comparison of yields which were taken on August 21. These are presented in Table 5. The plots receiving the foliar sprays were still green at the time of sampling and thus would have given a higher yield if left to mature and sampled at normal harvest. Table 5. Yields and Size Distribution of Potatoes from the Bay County Plots Treatment Lb. Tox. /A. Yield/A Cwt. Yield/ A Bu. % Size Distribution to 1 7/8" % Size Distribution 1 7/8" and up Thimet 10% Gran. Thimet 10% Gran. + Foliars* Disyston 10% Gran. Disyston 10% Gran. + Disyston 15% Gran.** Disyston 10% Gran. + Foliars* Untreated 2.2 lb. 2.2 lb. 2.2 lb. 2.2 lb. 3.0 lb. 2.2 lb. -- 354 349 384 390 378 328 590 582 640 650 630 547 5% 4 7 5 5 7 95% 96 93 95 95 93 * Applied by grower with boom sprayer: June 30—Guthion & Manzate; July 10—MSR & Manzate; July 20—Parathion, Sevin & Bravo; July 31—MSR & Copper; August 12—Lannate & Copper; August 24—Copper ** Granules sidedressed on each side of row at hilling (June 7). PHOSPHORUS-POTASSIUM SOIL TEST CORRELATION STUDY D. R. Christenson, C. Bricker, F. Wedel Department of Crop and Soil Sciences This experiment is part of a three year study to evaluate present fertilizer recommendations based on soil test levels. Consequently this should be considered a preliminary report; a final report will be published elsewhere. Methods The soil test levels in this experimental area were: pH 6.0, lime index 6.6, extractable phosphorus 314 lb/acre and extractable potassium 210 lb/acre. A randomized complete block experiment with 12 treatments (Table 1) and 4 replications was planted on May 5. Russet Burbank potatoes were grown and all fertilizer treatments were banded. Nitrogen was applied in a split application with 50 lb N/acre banded and 120 lb N/acre sidedressed June 30. A herbicide, fungicide, insecticide and irrigation program was followed. The plots were harvested on October 2. Results The yield and specific gravity results are presented in Table 1. The percent medium sized tubers was not affected by either phosphate or potash, but the percent large tubers tended to be increased by applied potash. There were no general trends for the effect of applied nutrients on percent small tubers. Yields were increased over the check by the application of 100 pounds of phosphate and 400 pounds of potash. A response was also obtained with the application 200 or 400 pounds of potash in combination with 100 pounds of phosphate as compared to phosphate alone. Tuber specific gravity was suppressed by the application of potash, but not by the application of phosphate. TABLE 1. Yield, percent small, medium, large and over 10 ounce, and specific gravity of Russet Burbank potatoes as affected by phosphorus and potassium applications. Fertilizer P2O5 Application K2O1b/acre Total Yield Size* Small % Size* Mediu Size* Large % Specific Gravity 1b/acre 50 50 50 100 100 100 200 200 200 100 0 0 empty table cell 100 200 400 100 200 400 100 200 400 0 200 0 LSD (5%) cwt/A 396.6 417.1 391.2 392.7 407.6 494.0 393.6 412.0 393.4 316.2 379.0 351.3 83.2 m % 82.7 83.3 84.2 86.9 81.6 83.8 82.0 80.9 78.6 83.8 87.0 82.8 NS 6.6 6.6 6.1 7.4 6.8 4.9 7.6 6.8 6.3 9.3 2.2 7.1 3.3 4.1 3.4 5.7 2.2 4.4 4.0 3.8 4.4 8.1 1.9 3.8 2.8 2.8 *Small, less than 1 7/8 inches; large, over 10 oz. 1.080 1.076 1.074 1.080 1.076 1.072 1.080 1.077 1.072 1.082 1.076 1.083 0.003 WATER MANAGEMENT OF POTATOES Ana Garay, R. J. Kunze, R. W. Chase and E. Kidder Departments of Crop and Soil Sciences and Agricultural Engineering As this is a two-year project dealing with various aspects of soil water management in potato production, some of the 1971 data are again referred to to permit a comparative interpretation with 1972 data. Inasmuch as the 1971 data showed that day versus night irrigation was not a factor in disease incidence or yield, other objectives thought to be more important were pursued in 1972. Objectives 1. To determine the effect of time of initiation of irrigation on the quality and yield of tubers. In 1971 irrigation was started at 50 (treatment 1); at 60 (treatment 2); and at 70 (treatment 3) days after planting. In 1972, the initial irrigations were applied at 30, 50 and 70 days, respectively. 2. To measure the effect of two levels of irrigation cooling. Intermittent, low volume sprinkler irrigation was applied in 1971 whenever the temperature was higher than 75: (C-1) and 80F (C-2). In 1972 the tempera­ ture levels were changed to 80 and 85F, respectively. 3. To devise an accurate and simple scheme for determining the frequency and volume of crop irrigations. Precipitation gains, evaporative losses, soil type and crop stages are considered and programmed into this scheme. 4. Two objectives were added to the 1972 research project. a. Frequency and volume of the irrigations. A 1/2" water application was compared with a 1" application (this resulted in two 1/2" irrigations per week versus a 1" irrigation per week). b. Periodic nitrogen application through the irrigation system. These applications were: N1 (check) - 120 lbs of N sidedressed at hilling time N2 - 60 lbs of N sidedress at hilling time plus 60 lbs applied in 3 equal irrigation applications at 2 week intervals after hilling N3 - 120 lbs of N applied at 6 weekly intervals of 20 lbs per irrigation. All plots had the same banded application of 800 lbs of 14-14-14 + 2% Mg at planting. Procedure The plots were irrigated with an elevated rotary sprinkler positioned at the center of each plot. Water volume meters were used to measure the water applied to each plot. Uniformity of distribution was adequate. A five-foot border was allowed between plots. Approximately 50 soil water sensing devices (tensionmeters and moisture blocks) were installed in the test area. Daily meteorological data were taken from a weather station adjacent to the experimental site. Russet Burbank and Kennebec potatoes were planted on May 10, 1972. The fertilization program in pounds/acre was: 120 K at plow-down; 110 N - 110 P - 110 K - 16 Mg banded at planting; and 120 N as described under objective 4b. All plots other than N1, N2, and N3 treatments were har­ vested September 15. The nitrogen treated plots were harvested October 5. Results and Discussion Table 1 shows that the average temperature for June 1971 was 11 degrees higher than for the same period in 1972. June is considered as the early tuberization period for most potatoes grown in Michigan. Other climatic conditions, particularly rainfall, had an entirely different pattern in 1972 when compared with 1971. Table 1 shows that not only was precipitation low during the growing season in 1971, but the pan evaporation was higher. Hence, the water deficit was 13.72 inches higher in 1971. This is also shown by the amount of irrigation applied (Table 2) for the two years. In conclusion, the 1971 season was hot and dry with a low relative humidity; the 1972 season was cool and wet, with a high relative humidity. All of the meteorological data and some yield data reflect these two contrasting situations. 1) Initiation and Frequency of Irrigation In 1971 the yield from Russet Burbank potatoes (Tr. 1- Table 3) was 155 cwt/A larger or an 87% increase over that of the check plot. Likewise, the percentage of knobby tubers decreased from 43.4% (check plots) to 13.5%. The same treatment in 1972 produced a decrease rather than an increase in yield and no effect on the percentage of knobs was observed. A similar trend may be seen in the Kennebec variety in Table 4. It should be pointed out that irrigation applied at a frequency of 1/2 inch per irrigation gave a higher yield trend (not shown in tables) for both the Russet Burbank and Kennebec varieties. The fact that several 1" and 1/2" irrigation applications were followed by intensive rains suggest that yields were depressed by excessive water. Ample rainfall during the 1972 growing season eliminated any differential soil moisture stress and masked any differences due to the time of initiating the irrigation. As a consequence, a valid test for relating initiation and timing of irrigation to potato yields could not be made in 1972. Table 1. Precipitation, Pan Evaporation and Temperature During the Potato Irrigation Period. Montcalm (1971 and 1972). Empty table cell Empty table cellPrecipitation Inch 1971 1971 July 1971 August 1971 Total June (15-30) 0.38 1.23 2.67 4.28 (inch) 4.47 0.28 8.60 0.28 0.22 6.70 0.25 19.77 Pan Pan Evaporation Evaporation Total Daily Ave.(inch) Daily Mean Temperature 1972 June (15-30) 1.88 1972 3.83 1972 7.29 1972 13.00 July August Total 2.88 0.18 6.66 0.21 4.07 0.13 13.61 0.17 Precipitation Minus Evapor. (inch) - 2.93 - 7.37 - 4.03 -14.33 - 1.00 - 2.83 3.22 0.61 °F 73.1 67.8 67.6 69.5 62.0 68.2 67.0 65.3 Table 2. Amount of irrigation applied according to treatments in 1971 and 1972 (in inches). empty table cell Frequency of Irrigation and Timing of Initial Irrigation 1" frequency 1 1971 10.0 1972 3.75 Frequency of Irrigation and Timing of Initial Irrigation 1" frequency Frequency of Irrigation and Timing of Initial Irrigation 1" frequency 3 Frequency of Irrigation and Timing of Initial Irrigation 1" frequency Check Frequency of Irrigation and Timing of Initial Irrigation 1/2” frequency 1 Irrigation 1/2” frequency of Initial Irrigation 1/2” frequency 3 and Timing of Initial Irrigation 1/2” frequency Check Empty Table Cell — 2 2 8.0 6.0 — Empty Table Cell 2.75 1.0 — 3.0 2.5 0.5 — Frequency of Irrigation and Timing of Initial Frequency of Irrigation and Timing Frequency of Irrigation Nitrogen Nitrogen Nitrogen Irrigation Cooling* Irrigatio n Cooling Irrigatio Empty Table Cell Empty Table Cell Empty Table Cell Empty Table Cell 1 2 Check 1 * 2 n Cooling*Check 12.3 11.0 10.0 3.75 Empty Table Cell Empty Table Cell 6.35 4.45 3.75 * Sum of normal irrigations plus irrigation cooling Table 3. Average yields, specific gravity and knobiness of Russet Burbank potatoes under one inch irrigation regime (1971 and 1972). empty table cell Check* Treatment 1 Treatment 2 Treatment 3 1971 Specific Gravity 1.0686 1.0756 1.0738 1.0711 1971 Knob s (%) 43.4 13.5 14.9 21.6 1971 Yiel d (cwt/A) 178.9 334.2 302.0 292.9 1972 Yiel d (cwt/A) 354.2 324.1 312.1 316.7 1972 Specific Gravity 1.0715 1.0757 1.0725 1.0680 1972 Knobs % 12.8 11.1 12.6 12.5 Table 4. Average yields and specific gravity of Kennebec potatoes under one inch irrigation regime (1971 and 1972). empty table cell Check* Treatment 1 Treatment 2 Treatment 3 1971 Yield (cwt/A) 165.8 328.9 306.2 285.8 1971 Specifi c Gravity 1.0628 1.0671 1.0633 1.0607 1972 Yield (cwt/A) 345.9 371.5 429.7 362.4 1972 Specific Gravity 1.0630 1.0667 1.0665 1.0637 *Check: no irrigation; Treatment 1, 2, 3 = different times of starting irrigation, Treatment 1 being the first irrigated. 2. Irrigation Cooling Experiment In 1971 the irrigation cooling treatments consisted of a 5 minute irrigation every 30 minutes whenever the temperature exceeded 75F (C-1) and 80F (C-2). This resulted in 34 days of irrigation cooling and a total of 2.3 inches of water applied for C-1, and 14 days and 1 inch of water for C-2. In 1972 these figures were 30 days with 2.6 inches of water applied for C-1 and 10 days with 0.7 inch for C-2. Because of changes in method of application larger amounts of water would be applied for cooling in 1972. Hence, the temperature levels were raised to 80 and 85F, respectively. The equipment and operation for the irrigation cooling study was more accur­ ately controlled in 1972. Unfortunately the potato plants were not stressed sufficiently to rigorously test the cooling effect in terms of yields. The data are presented in Table 5. The consistently higher yield in both 1971 and 1972 obtained with C-2 over C-1 is not easily explainable. Potatoes are considered a cool temperature plant and with the artificially imposed cooler environment one would expect a yield increase. However, the greater amount of water applied may again have depressed yields. 3. Scheme for Determining Time to Irrigate The technique of deciding when and how much water to apply for irrigation of potatoes consisted of keeping a daily record of soil water gains and losses. The daily balance of water available in the root zone is obtained by subtracting the daily evapotransperation (ET) loss and adding any gain from precipitation. When the water balance approached a critical level, water was supplied by irrigation. An amount was added which was considered adequate but insufficient to fill the entire storage capacity of the soil. Figure 1 shows the bookkeeping plan for potatoes irrigated with 1" of water per irrigation, starting 30 days after planting. The space between the two horizontal lines represents the soil storage for plant-available-water. The idea is to keep the daily soil water status between the two horizontal lines. This procedure differs in two ways with the procedure presented in 1971 Montcalm County Research Report. a) The lines are not plotted on a diagonal; hence no accumulative loss of water is kept. b) The daily loss of water varies with development of the plant canopy and with the daily or weekly pan evaporation. The straight diagonal line in 1971 assumed a constant loss for the entire growing season. The daily evapotranspiration loss was estimated by multiplying the Class A weather pan evaporation data by a factor corresponding to the canopy development of a crop. The factor reaches its maximum of 0.8 when the crop canopy is fully developed. For the period 30-40 days after planting, 0.5 was used as the factor; for 40-50 days, 0.6; for 50-60 days, 0.7 and from then on 0.8. The pan loss multiplied by the appropriate factor was obtained for each day and was drawn on the graph as a solid line going downward indicating water loss. When rainfall occurred, it was drawn as a solid line directed upward indicating water gain. Irrigations are indicated by dashed lines drawn upward. The graph cannot exceed the upward boundary even if extensive rainfall occurs. The U. S. Weather Bureau obtains pan evaporation data from six sites in Michigan. These sites are Dearborn, East Lansing, Germfask, Lake City, Lupton and South Haven. The climate most similar to the Montcalm Research Farm is that of Lake City. If one does not have access to these weekly pan losses then a loss of 0.2 inch per day is recommended. These data would be converted as follows: a. 30-40 days after planting - 0.20" x 0.5 = 0.10"/day b. 40-50 days after planting - 0.20" x 0.6 = 0.12"/day c. 50-60 days after planting - 0.20" x 0.7 = 0.14"/day d. 60- days after planting - 0.20" x 0.8 = 0.16"/day 4. Nitrogen Applications with Irrigation Water Table 6 depicts the yield response of Russet Burbank and Kennebec potatoes to periodic applications of nitrogen fertilizer through the irrigation system. There is a definite response to partitioning the nitrogen fertilizer but there is no clear indication suggesting that three 20 lb/A applications is superior to six 20 lb/A applications, or vice versa. Applying the nitrogen fertilizer at later times in the growing season increased the average yield about 70 cwt/A. The high rainfall during the latter part of the growing season may have leached the nitrogen and contributed to a reduced yield for the check plot. Table 5. Effect of sprinkler irrigation cooling on yield and specific gravity of Russet Burbank and Kennebec potatoes (1971 and 1972). empty table cell Russet Burbank 197 1 Yield (cwt/A) Russet Burbank 197 1 Russet Specific Gravity Burbank 197 2 Yield (cwt/A) Russet Burbank 1972 Specific Gravity c Kennebe c 1971 Yield (cwt/A) Kennebe Kennebe 1971 Specifi c Gravity 2 Yield (cwt/A) c 197 Kennebe c 1972 Specific Gravity Check 265.8 1.0727 343.3 1.0743 265.0 1.0607 392.0 1.0650 Treatment 1 315.9 1.0767 359.7 1.0763 315.0 1.0637 370.0 1.0673 Treatment 2 374.7 1.0752 378.9 1.0753 324.0 1.0650 392.7 1.0657 Table 6. Effect of the splitting of nitrogen fertilization on yield and specific gravity of Russet Burbank and Kennebec potatoes (1972). empty table cell Russet Burbank Yield (cwt/A) Russet Burbank Specifi c Gravity Kennebe c Yield (cwt/A) Kennebe c Specific Gravity Check Treatment 1 Treatment 2 343.3 394.0 427.3 1.0743 1.0676 1.0717 392.0 480.0 447.9 1.0650 1.0677 1.0647 FIG.1 SOIL AVAILABLE WATER BALANCE FOR SCHEDULING POTATO IRRIGATIONS TREATMENT 1-1972 THE EFFECT OF HARVEST DATE AND STORAGE ON THE YIELD POTENTIAL OF ONAWAY AND SEBAGO SEED POTATOES R. W. Chase Department of Crop and Soil Sciences Procedure This is the third and final year of this study to evaluate the harvest and storage factors which may influence potential seed quality. Seed of the Onaway and Sebago varieties was harvested on several different harvest dates and placed in storage at East Lansing either at 40F or stored for 14 days at 65-70F and then transferred to a 40F storage. Approximately one week before planting the seed was warmed to 50-55F, cut and then hand planted at a uniform spacing (12 inches) and uniform number of seed pieces per plot (25). Both varieties were planted on May 9. Fertilizer applied consisted of: plowdown, 200 lb/A 0-0-60; planting time, 800 lb/A 14-14-14 + 2% Mg; and sidedress, 115 lb N/A. A summary of the 1971 harvest and storage conditions is as follows: ONAWAY Treatment No. Topkill Harvest Date Storage Condition(F) Days Growing Days to Harvest 1 2 3 4 5 6 7 -- -- Aug. 3 -- -- Aug. 20 -- Aug. 3 Aug. 3 40 70-40 Sept. 28 Aug. 20 40 40 Aug. 20 70-40 Sept. 28 Sept. 28 40 40 91 91 91 108 108 108 147 91 91 147 108 108 147 147 SEBAGO Treatment No. Topkill Harvest Date Storage Condition (F) Days Growing Days to Harvest 1 2 3 4 5 6 7 — — Aug. 20 — — Sept. 7 — Aug. 20 40 Aug. 20 70-40 Oct. 7 Sept. 7 40 40 Sept. 7 70-40 Oct. 7 Oct. 7 40 40 108 108 108 126 126 126 126 108 108 156 126 126 156 156 Results and Discussion Table 1 summarizes the Onaway yield data. The lowest yields did occur with treatment numbers 1, 3, 6 and 7. The reduced yield of treatment 1 is due primarily to the physical condition of the seed at planting time. Seed harvested this early is too immature to be stored in adverse conditions. The only difference between treatments 1 and 2 is the storage environment of the tubers directly after harvest. The tubers from treatment 1 were held at 60-65F for approximately 3 days whereas those of treatment 2 were main­ tained at 60-65F for 14 days before being placed in the 40F storage. Obviously, 3 days is insufficient for proper curing and wound healing. Tubers harvested this year were very immature and very susceptible to skinning and bruising. In contrast, the low yield of treatment 3 represents some internal change and is not a result of physical damage. These plots were top killed on the same day that treatments 1 and 2 were harvested, however, the tubers remained in the ground for an additional 56 days. At the second harvest date there is little to no real difference between treatments 4 and 5. At this time the tubers were more mature so apparently the length of curing time was less critical. However, if the tubers were left in the ground for an additional 39 days as they were in treatment 6, the re­ sulting yields decreased by 41 cwt/A below that of treatment 5 and were the same as treatment 7 which serves as the fully matured check. TABLE 1. Effect of harvest date on the yield potential of Onaway seed potatoes. Treatment No. Total cwt /A Percent Size Percent Size Distribution Distribution -1 7/8 + 3 1/4 Percent Size Distribution 1 7/8 to 3 1/4 Specific Gravity 1 2 3 4 5 6 7 356 458 311 424 433 392 395 6.3 4.4 4.9 6.9 5.3 8.0 6.8 9.8 17.8 13.6 10.1 15.4 14.7 14.4 83.9 77.8 81.5 83.0 79.3 77.3 78.8 1.064 1.064 1.067 1.065 1.065 1.064 1.065 TABLE 2. Effect of harvest date on the yield potential of Sebago seed potatoes. Treatment No. Total cwt/A Percent Size Distribution -1 7/8 Percent Size Distribution +3 1/4 Percent Size Distribution 1 7/8 to 3 1/4 Specific Gravity 1 2 3 4 5 6 7 424 422 301 362 401 359 358 5.4 6.0 3.8 5.7 5.0 4.5 3.9 18.1 12.5 24.7 12.1 9.6 14.1 16.1 76.5 81.5 71.5 82.2 85.4 81.4 80.0 1.065 1.066 1.064 1.063 1.066 1.064 1.061 Table 2 summarizes the Sebago yield data. The yield differences between treatments 1 and 2 did not exist here as they did with the Onaway, however, there is a difference between treatments 4 and 5. The reason for this diff­ erence at a later harvest date is uncertain. There is however, the same yield reduction with treatments 3, 6 and 7. The delay in the removal of the tubers from the ground does have some effect on the subsequent yield potential and this did occur with both varieties. The effect on size distribution is less certain. Very little difference occurred with the Onaway and that of the Sebago is not consistent. The effect on specific gravity is similar. Tables 3 and 4 summarize the combined three year results. The observations noted for yields from the 1972 results are the same as those noted in the combined 3 year data. The earlier harvested seed which is properly cured and stored does have the greatest yield potential compared to a seed crop which reaches full natural maturity or is top killed and the tubers allowed to remain in the ground too long. In terms of size distribution there is a slight trend toward a greater percentage of tubers over 3 1/4 inch in the later harvested seed (treatments 3, 6 and 7). This pattern, although not large, does exist in both varieties. There appears to be no difference in the effect on specific gravity. TABLE 3. The combined 3 year summary of the effect of harvest date on the yield Percent Size Distrib. 1 7/8 to 3 1/4 76.3 73.9 69.4 71.8 76.2 68.4 69.4 Specific Gravity 1.067 1.068 1.069 1.065 1.067 1.066 1.067 potential of Onaway seed potatoes. Percent Size Distrib. Percent Size Distrib. Treatment No. No. Days Growing No. Days to Harvest 1 2 3 4 5 6 7 86 86 86 105 105 105 132 86 86 132 105 105 132 132 Storage Temp. (F) Cwt/A 40 70-40 40 40 70-40 40 40 365 424 339 405 426 392 377 -1 7/8 4.7 3.6 4.1 4.1 4.0 5.0 4.2 +3 1/4 19.0 22.5 26.5 24.1 19.8 26.6 26.4 TABLE 4. The combined 3 year summary of the effect of harvest date on the yield potential of Sebago seed potatoes. Treatment No. No. Days Growing No. Days to Harvest Storage Temp. (F) Cwt/A -1 7/8 +3 1/4 1 7/8 to 3 1/4 Specific Gravity 1 2 3 4 5 6 7 105 105 105 125 125 125 150 105 105 150 125 125 150 150 40 70-40 40 40 70-40 40 40 390 412 337 364 397 368 359 3.8 3.5 3.3 3.3 3.3 3.3 3.2 21.5 19.2 25.3 20.6 21.1 23.2 25.0 74.7 77.3 71.4 76.1 75.6 73.5 71.8 1.065 1.067 1.066 1.066 1.067 1.065 1.065 THE RELATIONSHIP OF PLANTING DATE, HARVEST DATE AND STORAGE TEMPERATURE ON THE YIELD POTENTIAL OF RUSSET BURBANK SEED POTATOES R. W. Chase Department of Crop and Soil Sciences A three year study was initiated in 1972 to evaluate the effects of planting date, harvest date and storage temperature on the vigor and yield potential of the Russet Burbank. The objective is to relate the production management factors which may influence subsequent yield potential. Procedure Premier-Foundation Russet Burbank seed was planted on three different dates, May 9, May 18, and May 31, 1972. Within each planting, four harvest dates were included, August 15, September 1, September 15 and October 4, with each replicated three times. Plots were harvested and the yield, grade and specific gravity were determined. Two-one bushel samples from each plot were collected at harvest and placed in storage at 60F and 90% RH for two weeks. At the end of this curing time one sample was placed in storage at 40F and the second at 34-35F. These will be planted in 1973. TABLE 1. The total yield, size distribution and specific gravity of Russet Burbank potatoes at several different planting and harvest dates. Planting Date Harvest Date Days Growing Total Yield May 9 May 9 May 9 May 9 May 9 May 9 May 9 May 9 May 9 May 9 May 9 May 9 Aug. 15 98 Sept. 1 115 Sept. 15 130 Oct. 4 149 Aug. 15 89 106 Sept. 1 Sept. 15 121 Oct. 4 140 76 Aug. 15 Sept. 1 93 Sept. 15 108 127 Oct. 4 289 335 376 368 244 313 365 370 97 169 277 289 Percent Size Percent Size Distribution Distribution -1 7/8 Off Type 9.2 14.8 15.6 8.7 13.4 7.3 7.0 12.7 3.5 19.6 13.8 10.5 10.8 10.7 12.8 14.3 0.5 56.8 18.9 21.7 14.0 7.3 8.4 19.5 + 10 oz. 3.3 7.8 17.7 17.1 0.1 2.5 13.4 8.4 0 0 9.3 9.0 Percent Size Distribution 1 7/8 to 10 oz. Specific Gravity 72.7 67.9 61.7 63.2 76.8 73.2 65.1 64.5 42.7 59.4 69.4 63.1 1.074 1.075 1.076 1.073 1.075 1.076 1.079 1.073 1.065 1.070 1.077 1.073 Results and Discussion Yield and quality are the only data available at this time and are summarized in Table 1. Regardless of planting date, there was no appre­ ciable yield advantage in delaying the time of harvest from September 15 to October 4. None of the plots were topkilled. In fact the specific gravity readings show a very definite decrease with delay in the final harvest. This probably relates to the wet conditions which occurred late in the growing season. SOIL FERTILITY RESEARCH WITH DENT CORN, SWEET CORN AND DARK RED KIDNEY BEANS M. L. Vitosh Department of Crop and Soil Sciences In 1972 three soil fertility experiments were conducted with dent corn, two with sweet and two with dark red kidney beans. The experiments with dent and sweet corn were part of a rotation with potatoes. Growing conditions for corn were excellent and very little irrigation was required. Plot technique and general management practices are given at the bottom of each table. Source, Rate, and Time of Nitrogen Application with Dent Corn: In this experiment comparisons of broadcast vs sidedress N applications and urea vs sulfur-coated urea were made. The experimental design was a split plot with two corn hybrids (Mich 500-2X and Mich 396-3X) in each plot. Corn was planted to get a stand of 24,000 plants per acre and later thinned to 22,500. Grain and silage yields were taken for both hybrids. Results of the study are repeated in Table 1. Average grain yields were more than tripled with 180 lbs of N/A. Sidedress applications of N especially at the higher rates resulted in a larger yield than broadcast N. In general sidedress applications of N resulted in more efficient use of N. Average silage yields were increased 5 tons/A with 60 lb N/A (SCU) and 8 to 10 tons with 120 or more lbs N/A. Sidedress N applications did not give better silage yields than broadcast applications. Michigan 396-3X generally yielded more grain but less silage than Mich. 500-2X Sulfur-coated urea in some plots tended to give better yields but the overall response indicated no difference between urea and sulfur-coated urea. Potassium-Magnesium Study with Dent Corn: This experiment contained 10 K treatments of varying rates at two plant populations. Four of the K treatments received 50 lbs Mg/A while four comparable K treatments did not. Mich. 500-2X was planted in one-half of each plot to obtain approximately 24,000 and 28,000 plants per acre. After emergence each plot was thinned to 22,500 and 26,200 plants per acre. Results of the study are shown in Table 2, Grain and silage yields were not significantly affected by the K treatments but some trends exist. In many plots the lower plant population gave larger yields than the higher population. Both grain and silage yields showed a slight increase with the first 50 lbs of potash applied. Nitrogen Residual Study with Dent Corn: This study was conducted on the area which grew potatoes in 1971. The plots were fertilized with various rates of N up to 300 lb/A in 1971. Corn was planted in 1972 with no N. Similar studies with beans previously showed no carry-over effect of N fertilizers. The rotation was changed in 1972 to include corn to evaluate the residual N effect. The crop was irrigated and harvested for grain and silage. Yields results are presented in Table 3. Residual effects were quite noticeable throughout the entire summer. The check plot showed signs of severe N deficiency but yielded very well. Plots which received 60 lbs N/A (sulfur-coated urea) in 1971 yielded an additional 27 bushel of grain and 2.8 tons of silage. Plots which received 120 to 180 lbs of sidedress N in 1971 resulted in larger grain and silage yields than plots receiving equivalent amounts of broadcast N. Plots receiving SCU also tended to yield better than corresponding urea treatments. Corn, which has a more extensive rooting system than beans resulted in more efficient recovery of N from the previous years application. It would appear the SCU does not release all of its N in one growing season and some additional N may be recovered by corn the following year. Potassium-Magnesium Study with Sweet Corn: Sweet corn yields in 1972 were not significantly affected by the K-Mg treatments in this experiment (Table 4). All K treatments however gave higher yields than the check plot indicating a slight response to K. The three year average also shows a slight response to K fertilizer. The overall average for the four K treatments with Mg and comparable K treatments without Mg indicates no significant difference in yield. The yield data are consistent with the soil test recommendation that this soil does not need Mg fertilizer. Nitrogen Carrier Study with Sweet Corn: Sweet corn yields in 1972 were not significantly affected by the five sources of N fertilizer (Table 5) but ammonium sulfate and anhydrous ammonia tended to out-yield the other N sources. The five year average shows that urea and anhydrous ammonia gave a slight yield advantage. Calcium nitrate continued to result in the lowest yields. These same trends have been observed with potatoes. Nitrogen and Sulfur Studies with Dark Red Kidney Beans: Two experiments with dark red kidney beans were conducted in 1972. Experi­ ment A involved nine fertilizer treatments with varying rates of N and S. Experiment B had N and S treatments but at much higher N rates. Results of these two experiments are reported in Tables 6 and 7. Bean yields were not significantly affected by any of the treatments, however, 80 lb S/A with N fertilizer tended to reduce yields in both experiments. Sulfur at rates of 1 and 4 lb/A with 40 lb N/A gave the largest yields in experiment A. Another investigator has reported that a N:S ratio of 16:1 is best for yields and protein synthesis on soils which are deficient in sulfur. Best yields in this experiment were obtained at N:S ratios of 40:1 and 10:1. The sulfate sulfur level in this soil is just above the critical level at which a yield response would be expected. The percentage of non-protein N in experiment A was relatively constant for all treatments. Protein N for the same experiment was significantly increased with 40 lbs of N and no sulfur. Sulfur fertilizer had a tendency to increase the protein N but the increase was not statistically significant. In experiment B both protein and non-protein N content was affected by the treatments. Nitrogen fertilizer at 100 lb N/A without sulfur increased both the percent protein and non-protein N over the check. When 200 lb N/A without S was applied only the protein N fraction was increased. The non- protein N content was the only fraction increased with 40 lb S/A and 100 lb N/A. In summary sulfur fertilizer had little influence on the protein content of the dark red kidney bean at this location. Nitrogen fertilizer without S had the greatest effect in increasing the protein content and only in one instance was the non-protein fraction increased. TABLE 1. Effect of rate, source and time of nitrogen application on grain and silage yields of two irrigated corn hybrids. Nitrogen Application (a) Broadcas t1b N/A Nitrogen Application (a) Nitrogen Nitrogen Application (a) Sidedressed 1b Application (a)TotalNlb N/A Mich. Mich. 396-x Silage Yield (tons/acre) (b) 396-3x Grain Yiel d (Bu/A) Mich. 500-2x Grain Yiel d (Bu/A) Mich. 500-2x Silage Yield (tons/acre) (b) Average Average Effects Silage Yield (tons/acre) (b) Effects Grain Yiel d (Bu/A) Banded 1b N/A N/A 0 60 SCU 60 U 120 U 180 U 60 SCU 0 0 0 120 SCU 0 0 60 U 60 U 60 U 60 U 60 U 60 U 60 U 60 U 0 0 0 0 0 0 60 U 120 U 180 U 0 LSD (.05) treatments empty table cellempty table cell 0 60 120 180 240 120 120 180 240 180 45 116 147 174 171 160 153 176 195 164 empty table cell- LSD (.05) Treatments within varieties empty table cell empty table cellempty table cell LSD (.05) varieties within treatments empty table cell empty table cellempty table cell 17 17 11.4 16.6 20.6 21.5 20.7 19.1 19.6 20.4 18.8 22.6 - 3 3 66 120 145 136 134 138 139 159 148 152 - 17 17 15.7 19.8 22.5 26.2 23.0 22.9 20.2 23.7 23.4 25.1 - 3 3 55 118 146 155 153 149 146 168 172 158 12 - - - 13.6 18.2 21.6 23.9 21.9 21.0 19.9 22.0 21.1 23.9 2 - (a) Broadcast urea (U) and sulfur-coated urea (SCU) was applied and plowed down one day before planting. Banded urea was applied at planting time 1 1/2 inches to side and 1 inch below the seed. Sidedressed urea was topdressed June 17, 1972. (b) Fresh weight yield at 69% moisture. Planted: May 4, 1972 Harvested:silage: September 21, 1972 Plant Population: 22,500 Row spacing: 28 inches Basic fertilizer: 0-50-100 banded at planting time Irrigation: 4.0 inches TABLE 2. Effect of potassium and magnesium on grain and silage yields of Michigan 500-2X com under irrigation. Potassium-Magnesium Potassium-Magnesium Application (a) Banded 1b Potassium-Magnesium Application (a) Broadcas t 1b Potassium-Magnesium Application (a)Broadcas Application (a)Tota lK2O 22,500 Grain Yiel d (Bu/A) 22,500 Silage Yield (b) Tons/Acre 26,200 Silage Yield (b) Tons/Acre Average Effects Grain Yield (Bu/A) Average Effects Silage Yield (b) Tons/Acre 26,200 Grai n Yield (Bu/A) t1b K2O/A K2O/A Mg/A 0 0 50 100 150 250 0 50 150 250 0 50 50 50 50 50 50 50 50 50 0 0 0 0 0 0 50 50 50 50 LSD (.05) treatments empty table cellempty table cell 0 50 100 150 200 300 50 100 200 300 154 158 162 147 151 154 151 155 157 168 empty table cellNS empty table cell NS empty table cell empty table cell LSD (.05) treatments within plant population LSD (.05) plant population within treatment empty table cell empty table cellempty table cell NS 21.3 24.5 24.9 24.9 25.8 25.0 23.5 24.6 25.5 26.0 - NS NS 140 147 150 152 149 158 156 150 152 152 NS NS NS 21.6 23.3 24.8 23.9 24.9 26.9 22.7 23.5 25.0 25.3 - NS NS 147 152 156 150 150 156 154 153 155 160 NS NS NS 21.5 23.9 24.9 24.4 22.5 25.9 23.1 24.0 25.2 25.6 NS NS NS (a) Broadcast potassium and magnesium were applied and plowed down 5 days prior to planting. Banded potassium was applied 1 1/2 inches to side and 1 inch below seed at planting time. Potassium and magnesium sources were KC1 and MgSo4. (b) Fresh weight yield at 71% moisture. Planting: May 4, 1972 Row spacing: 28 inches Basic fertilizer: 50-50-0 banded, 180 N sidedressed June 17, 1972 Irrigation: 4.0 inches Previous crop: potatoes Harvest grain: Oct. 9, 1972 Harvest area: 116 sq. ft. Soil test: pH = 6.4, P = 347, K range = 146-253, Mg = 210 Harvest silage: Sept. 21, 1972 TABLE 3. Effects of residual nitrogen on grain and silage yields of irrigated corn. Nitrogen Application (a) Broad cast 1b N/A Nitrogen Application (a) Nitrogen Application (a) Sid e Dresse Nitrogen Application (a)Totallb N/A Mich. 500-2x Grain Yiel d (Bu/A) Mich. 500-2x Silage Yield (Tons/A) Banded 1b N/A d 1b N/A 0 0 60 SCU 0 60 U 60 U 120 U 60 U 180 U 60 U 60 SCU 60 U 60 U 0 60 U 0 0 60 U 120 SCU 60 U LSD (.05)empty table cell 0 60 120 180 240 120 120 180 240 180 0 0 0 0 0 0 60 U 120 U 180 U 83 110 109 114 130 127 104 130 147 125 empty table cellempty table cell20 0 13.4 16.2 16.3 15.0 15.5 16.1 16.4 17.0 17.8 19.0 2 (a) All nitrogen applied in 1971 Planted: May 4, 1972 Plant population: 24,000 Basic fertilizer: 0-50-50 banded at planting time Irrigation: 4.0 Harvest area: 233 sq. ft. Soil tests: pH = 6.5, P = 274, K = 196 Harvested silage: Sept. 22, 1972 Harvested grain: Oct. 10, 1972 Row spacing: 28 inches Previous crop: potatoes TABLE 4. Effect of potassium and magnesium on yield of irrigated sweet corn. Potassium-Magnesium Applications (a) Broad cas t1b K2O/A Potassium-Magnesium Potassium-Magnesium Applications (a) Banded 1b K2O/A Potassium-Magnesium Applications (a) Broa d cast 1b Mg/A Applications (a) Total K2O Sweet Corn Yield (cwt/A) 1972 Sweet Corn Yield (cwt/A) 1970-72 0 0 0 0 0 120 0 0 0 0 0 20 40 60 80 40 20 40 60 80 LSD (.05)empty table cell 0 0 0 0 0 0 50 50 50 50 0 20 40 60 80 160 20 40 60 80 98 112 125 112 126 113 115 115 120 115 empty table cellempty table cellNS 110 119 127 120 121 119 126 122 121 117 - (a) Banded potassium was placed 1 1/2 inches to side and 1 inch below seed at planting. Broad­ cast potassium and magnesium were applied and plowed down prior to planting. Potassium and magnesium sources were KCl and MgSO4 . Planted: May 3, 1972 Row spacing: 28 inches Basic fertilizer: 60-50-0 banded, 120 lb N/A sidedressed June 17, 1972 Harvest area: 116 sq. ft. Soil tests: pH = 6.9, P = 210, K = 166 Harvested: July 31, 1972 Plant population: 18,000 Irrigation: 4.0 inches Previous crop: corn TABLE 5. Effect of source of nitrogen on yield of irrigated sweet com. Source of Nitrogen Sweet Sweet Corn Yield (cwt/A) Corn Yield (cwt/A)1971 1968-72 Average Ammonium Sulfate (a) Ammonium Nitrate (a) Calcium Nitrate (a) Urea (a) Anhydrous Ammonia (b) LSD (.05) 131 121 122 123 139 NS - 119 116 112 121 127 (a) 140 lb N/A topdressed May 25, 1972 (b) 140 lb N/A sidedressed May 25, 1972 Planted: May 2, 1972 Row spacing: 28 inches Harvest area: 116 sq. ft. Basic fertilizer: 10-50-100 banded at planting time Soil tests: pH = 6.6, P = 289, K = 223 Harvested: August 9, 1972 Plant Population: 18,000 Irrigation: 4.0 inches Previous crop: soybeans TABLE 6. Effect of nitrogen and sulfur fertilizer on yield of grain and nitrogen content of Charlevoix dark red kidney beans (Experiment A). Fertilizer Application Nitroge n 1b/A Fertilizer Application Sulfur 1b N/A Red Kidney Red Kidney Bean Yield (Bu/A) Bean Protein N (%) Red Kidney Bean Non Protein N (%) Red Kidney Bean Total N (%) 0 0 0 40 B 40 B 40 B 40 B 40 B 40 B LSD (.05) 0 40 PD (a) 80 PD (a) 0 1 (b) 4 (b) 8 (b) 40 PD (a) 80 PD (a) empty table cell 44 42 42 45 46 47 44 43 37 NS 2.54 2.60 2.59 2.71 2.65 2.56 2.59 2.59 2.62 .17 .38 .41 .40 .38 .36 .43 .41 .43 .42 NS 2.92 3.01 2.99 3.09 3.01 2.99 3.00 3.02 3.04 -- (a) Sulfur applied as gypsum and plowed down May 23, 1972 (b) Sulfur applied as potassium sulfate and banded at planting Planted: May 25, 1972 Plant Population: 58,500 Basic fertilizer: 0-50-50 banded at planting Irrigation: 3.0 inches Harvested: September 21, 1972 Row spacing: 28" Harvest area: 373 sq. ft. TABLE 7. Effect of nitrogen and sulfur fertilizer on yield of grain and nitrogen content of Charlevoix dark red kidney beans (Experiment B). Fertilizer Applied Nitrogen 1b/A Fertilizer Fertilizer Applied Sulfur 1b/A Applied Source 1b/A 0 0 100 200 100 200 0 40 0 0 40 80 KCL K2SO4 KCL KCL K2SO 4 K2SO4 + Gypsum LSD (.05) empty table cell empty table cell N & S disced in May 23, 1972 Red Kidney Bean Yield (Bu/A) 41 42 44 42 44 38 NS Red Kidney Bean Protein N (%) Red Kidney Bean Non Protein N (%) Red Kidney Bean Total N (%) 2.59 2.61 2.78 2.82 2.67 2.68 .12 .47 .49 .52 .44 .52 .48 .05 3.06 3.10 3.30 3.26 3.19 3.16 - Planted: May 25, 1972 Plant Population: 58,500 Basic fertilizer: 0-50-120 banded at planting Irrigation: 3.0 inches Harvested: September 21, 1972 Row spacing: 28" Harvest area: 373 sq. ft. INSECTICIDE EVALUATION FOR BEAN INSECT CONTROL Arthur L. Wells, Department of Entomology The insecticide research on bean insects at the Montcalm Experimental Farm consisted of the evaluation of six soil systemic insecticide treatments banded below and to one side of the seed at the time of planting on June 16. The plots consisted of three replications of four 50 foot rows including two rows of Sanilac (white beans) and two rows of Charlevoix (dark red kidney) seed. The inside row of each variety in each plot was harvested on October 9 and yields determined. These data are presented below: Material and Formulation Rate/A.* Rate/A* Tox. Form. Yields/Acre whites Bu. Yields/Acre Whites Cwt. Yield/Acre Dark Reds Bu. Yield/Acre Dark Reds Cwt. Amer Cyan 92100 15% Gran. Thimet 15% Gran. Disyston 15% Gran. Diam Sham 15647 10% Gran. Furadan 10% Gran. Furadan 10% Gran. Untreated (avg. of four) 1 lb. 1 lb. 1 lb. 1 lb. 1/2 lb. 1 lb. -- 7 lb. 7 lb. 7 lb. 10 lb. 5 lb. 10 lb. -- 27.7 28.7 27.4 29.7 27.1 35.5 28.4 16.6 17.2 16.5 17.8 16.3 21.3 17.0 32.3 40.3 34.8 32.6 30.0 46.1 36.6 19.4 24.2 20.9 19.6 18.0 27.7 22.0 * Rates based on 30 in. rows (17,424 row-ft/A.) A heavy population of Mexican bean beetles developed by late August in all of the untreated plots but the excellent start and rapid plant growth still resulted in yields comparable to most treatments. The insecticides provided almost complete protection from the beetles. The yield from the one pound application of Furadan appears higher than that from other treatments in both varieties. Preplant Incorporated and Preemergence Herbicides for Weed Control in Field Beans at the Comden Farm, Montcalm Co., Michigan D. L. Wyse, W. F. Meggitt and R. C. Bond Department of Crop and Soil Sciences Gratiot and Sanilac field beans were planted and treated June 16, 1972 on a McBride sandy loam soil (1.5% organic matter). The postemergence treatments we e applied July 20, 1972. Design of the experiment was a randomized block with three replications. Rainfall was .64 inches within 10 days after herbicide application. The weeds present were lambsquarter and pigweed. The plots were visually rated for injury and weed control July 26, 1972. Preplant incorporated treatments. EPTC at 2 1b/A and 3 1b/A did not give satisfactory control of the pigweed population in this experiment. How­ ever, these treatments did give 87 and 90% control of the lambsquarter pop­ ulation. Trifluralin at 3/4 1b/A did not give good control of either the lambsquarter or pigweed population. EPTC + trifluralin at 2 + 1/2 lb/A controlled 87 and 80% of the lambsquarter and pigweed populations respectively. Alachlor at 2 lb/A did not give satisfactory control of lambsquarter and controlled 80% of the pigweed population. Alachlor + chloramben at 2 + 2 lb/A as a tank mix was the best preplant incorporated treatment resulting in 97% control of both broadleaf species. Dinitramine at 1/2 lb/A con­ trolled 97% of the lambsquarter and 83% of the pigweed populations. This treatment resulted in 20% injury to the field bean plants. Preplant incorporation-preemergence-and postemergence combinations. Two preplant incorporated herbicides, EPTC at 2 lb/A and trifluralin at 1/2 lb/ A, were applied and incorporated twice with a disk. The following four preemergence herbicides were subsequently applied in combination with the two preplant incorporated treatments: chloramben at 2 lb/A; fluorodifen, 3 lb/A; dinoseb + chloramben (2:1) 1 gal/A and dinoseb at 4 1/2 lb/A. BAS 3517-H at 1 1/2 lb/A was applied postemergence to the two preplant incorporated treatments. All EPTC at 2 lb/A preplant incorporated and pre­ emergence combinations gave 97 to 100% control of the two broadleaf species. The preemergence-preplant incorporated combinations involving trifluralin controlled 90% or more of both broadleaf species. BAS 3517-H at 1 1/2 lb/A postemergence in combination with EPTC at 2 lb/A and trifluralin at 1/2 lb/A controlled 100% of the lambsquarter population and 90 to 97% of the pigweed population. BAS 3517-H at 1 1/2 lb/A alone as a postemergence treatment controlled 73 and 50% of the lambsquarter and pigweed population respectively and caused 12% injury to the field bean. Preemergence. Three of the preemergence treatments - dinoseb, 4 1/2 1b/A; chloramben, 3 lb/A and alachlor + chloramben, 1 1/2 + 1 1/2 1b/A gave acceptable control of lambsquarter and pigweed. Fluorodifen at 3 lb/A and 4 1/2 lb/A controlled 97 to 100% of the pigweed population but was un­ acceptable in its control of lambsquarter. This experiment tends to show that for complete weed control in field beans a combination of preplant incorporated and preemergence herbicides should be considered. The pre­ plant incorporated herbicides in general give better overall weed control than do the preemergence herbicides when applied alone. Table 1. Preplant Incorporated and Preemergence Weed Control Evluations in Field Beans. Montcalm Co. Comden Farm Planted: June 20, 1972 Treated: PPI+Pre - June 16, 1972 Rated: Post - July 20, 1972 August 26, 1972 Weeds present: lambsquarter, pigweed Variety: Sanilac Soil Type: McBride sandy loam Organic Matter: 1.5% PPI Treatments Trmt No. PRE Treatments POSTTreatments empty table cellempty table cell EPTC EPTC Treflan EPTC + Lasso empty table cellempty table cell empty table cellempty table cell 3/4 Treflan empty table cellempty table cell empty table cellempty table cell empty table cell 2+1/2 2 Rate lb/A 2 3 Injury 0.0 0.0 0.0 0.0 0.0 1 2 3 4 5 6 7 8 9 10A Cobex Cobex Lasso +Amiben Lasso +Amiben EPTC +Amiben empty table cellempty table cell empty table cell empty table cell empty table cell empty table cell 0.3 1/2 2.0 1 0.0 2+2 1 1/2+1 1/2 0.0 2+2 0.0 11A EPTC +Preforan 12A EPTC +Dynoram 13A 14A empty table cell empty table cell EPTC + EPTC + empty table cell BAS 3517-H empty table cell DNBP 2+3 2+1 gal 2+4 1/2 2+1 1/2 10B 11B 12B 13B 14B Treflan + Amiben Treflan + Preforan Treflan + Dynoram Treflan + DNBP Treflan + empty table cell BAS 3517-H empty table cell 1/2+2 empty table cell 1/2+3 empty table cell 1/2+1 gal empty table cell 1/2+4 1/2 1/2+1 1/2 empty table cell Amiben 10C empty table cell 11C empty table cell Preforan 12C empty table cell Dynoram empty table cell empty table cell 13C empty table cell DNBP 14C empty table cell empty table cell BAS 3517-H empty table cell 15 2 3 1 gal 4 1/2 1 1/2 3 empty table cell Amiben empty table cell empty table cell Lasso + empty table cell EL 119 empty table cell Preforan Lasso +Amiben 1 1/2+1 1/2 0.0 16 0.0 17 1 1/2+3 0.0 1 1/2 18 0.0 4 1/2 19 -- 0.0 20 0 - No control and no injury; 10 - Complete control or kill Preforan empty table cell empty table cell empty table cellempty table cell Check 0.0 0.0 0.0 1.8 0.0 0.3 0.0 0.0 1.2 0.0 0.0 0.0 0.0 1.2 0.0 Weed Control Rating LQ Weed Control Rating PW 8.7 9.0 7.7 8.7 7.0 9.0 9.7 9.7 9.0 10.0 10.0 10.0 10.0 10.0 9.0 9.0 10.0 10.0 9.7 5.7 3.7 8.7 10.0 7.3 8.0 9.0 7.0 6.0 5.7 0.0 6.7 7.7 6.3 8.0 8.0 6.3 8.3 9.7 8.0 10.0 10.0 9.7 10.0 9.3 10.0 9.7 10.0 9.7 9.0 8.3 9.7 7.0 9.0 5.0 9.7 9.7 10.0 7.7 10.0 0.0 REPORT OF RESULTS OF DRY BEAN VARIETY TEST M. W. Adams Department of Crop and Soil Sciences The test in 1972 included 16 miscellaneous colored bean varieties or strains planted at the Montcalm Research Farm on June 13, in both 21 inch and 28 inch rows. The fertilizer used was 8-32-0, with 2% Mn and 2% Zn, applied at a rate of 250. pounds per acre at planting. A systemic insecticide, Thimet, was applied with the fertilizer at a 1.5 pound active per acre rate. The herbicide was Eptam. There were four replications per entry. Yield data are given in the accompanying table. TABLE 1. Yield data in cwt/acre of clean beans for 16 varieties of colored beans grown on Comden Farm, 1972. Variety or Strain Cwt per Acre 21" rows Cwt Per Acre 28" Rows Cwt Per Acre Average Light Red Kidney 01 Light Red Kidney 02 Light Red Kidney 03 22.04 23.01 24.87 20.98 Light Red Kidney Manitou 23.90 Light Red Kidney Redkote Dark Red Kidney 021 24.57 Dark Red Kidney 023 26.09 24.45 Dark Red Kidney Charlevoix California Dark Red Kidney 21.74 Expt. Cranberry 026 (Bush) Expt. Cranberry 027 (Bush) Expt. Cranberry 028 (Bush) Mich. Improved Cran.(Vine) Comm. Yellow Eye Merithew Selection (Large White) Swedish Brown (Bush) General Averages 26.39 24.23 30.06 22.97 21.32 23.52 30.78 24.43 21.53 24.19 24.73 23.59 26.03 23.75 22.76 26.98 21.88 23.40 23.94 26.22 27.04 24.10 20.73 31.17 24.50 21.79 23.60 24.80 22.29 24.96 24.16 24.43 25.72 21.81 24.90 24.09 28.14 25.00 22.71 22.12 30.98 24.46 Discussion of Results On the overall average there was no difference between beans in 21 and 28 inch rows. But among the 16 strains there was a comparison of particular interest, the bush-type cranberry bean selections all yielded better in the 21 inch rows, and exceeded the vine-type by up to 7 cwt. per acre. In the 28 inch row the vine-type slightly exceeded the better bush. The most consistently good yielder was the Swedish Brown bean, not at present a commercial type. This bean is a bush type and is early in maturity. It yielded equally well in both row spacings. As for the kidney strains, plans are underway to increase seed of LRK 03 and DRK 023, the better strains of their classes. These strains are resistant to the halo blight disease, whereas the standard varieties are susceptible. 1972 GRAIN AND FORAGE SORGHUM TRIALS Stuart Hildebrand Department of Crop and Soil Sciences The basic reason for producing grain and forage (silage) sorghum in Michigan is as a substitute for corn on droughty soils where they are geographically adapted. In 1972, six grain and two silage-type forage sorghum hybrids were entered in a trial at the Montcalm Farm to determine their adaptation for maturity and production per acre. Selection of hybrids was based on previous performance in southwest Michigan trials, with the grain hybrids varying in bird resistance. Seed was planted on May 31 in 28 inch rows, 20 feet long and each hybrid was replicated 4 times. Because of previous treatment no fertilizer was applied at planting but 100 pounds per acre of nitrogen was applied later as a sidedressing. Emergence was delayed by cold and dry weather. Silage harvest was made September 26. Frosts occurred on October 10 and 11 and grain harvest followed on October 16. Yield and other appropriate information follow: Hybrid MM-54 BR Pride 500A Acco 920 Dorman 100 So. Dakota 506 NK 121 Hybrid NK 300 Pioneer 931 Grain Sorghum Yield in bu. per acre 14% M. Remarks 69.5 63.2 52.2 73.5 55.9 75.8 Mature at harvest. Little bird damage. Immature at harvest. Slight bird damage. Mature at harvest. Moderate bird damage. Immature at harvest. Little bird damage. Mature at harvest. Considerable bird damage . Mature at harvest. Little bird damage. Forage Sorghum Yield of silage in tons per acre 70% M Remarks 17.8 28.9 5-3/4 feet tall. 75,000 plant population. Has about 20 to 25 percent grain. 12 feet tall. 87,000 plant population. Very little grain. Hard to cut. Both varieties had 72% moisture at harvest. Usually NK 300 contains less moisture. It appeared that Pioneer 931 was short of nitrogen near the end of the season. For information on feeding trials on the two sorghums refer to MSU Research Report 174, 1972 Report of Beef Cattle Research, August 1972. CORN HYBRIDS, PLANT POPULATION AND IRRIGATION E. C. Rossman and Bary M. Darling Department of Crop and Soil Sciences 72 commercial and experimental corn hybrids were evaluated in 1972 with irrigation and without irrigation, Table 1. Six inches of irrigation water were applied (1 1/2" on July 7, 11, 24, 30). Buoyoucous soil moisture blocks were placed at 6, 12, 18, and 24-inch depths in both unirrigated and irrigated plot areas. Soil moisture in the unirrigated plots was below 50% water holding capacity at 6-12" for only a short time in July and was 80-100% at 18-24" throughout the growing season. Nearly adequate rainfall during the growing season in 1972 contrasts with 1971 when soil moisture remained below 50% at 12-24" depths from July 5 to August 30 on unirrigated plots. Irrigated yields in 1972 averaged 157.3 bushels and unirrigated yields average 136.6 bushels—a difference of 20.7 bushels for the 6" of irrigation applied in July. Comparable yields in 1971 were 162.5 irrigated and 28.2 not irrigated—a difference of 134.3 bushels for 12 1/2" of irrigation. Hybrids ranged in yield from 98.5 to 206.3 irrigated and 90.5 to 179.1 not irrigated. Five-Year Averages 1968-1972 Table 2 presents a five-year summary of yields and stalk lodging. Irrigated corn yields averaged 149.1 irrigated and 89.8 not irrigated for the five-year period—a difference of 59.3 bushels. The highest yielding hybrids averaged 79.4 bushels more when irrigated (195.5 vs 116.1) and the lowest yielding hybrids averaged 36.2 bushels more (94.7 vs 58.5). Irrigation response of the highest yielding hybrids was more than twice as great as the response of the lowest yielding hybrids, 79.4 vs 36.2 bushel increases from irrigation. Stalk lodging. During the first three years, 1968-1970, there was more stalk lodging on unirrigated plots. Stalk lodging averaged higher on irrigated plots during the last two years, 1971-1972. ________________ _______ _________________ Plant Population x Irrigation Five hybrids at five plant populations irrigated and not irrigated were grown in each of five years, 1968-1972. Yields and stalk lodging are summarized in Table 3. Yields. Highest yields with irrigation were reached at a population of about 23,100 (181.3 bu.) and decreased at the highest plant population (27,200) to 163.8 bushels during the five years. Without irrigation, highest yields were attained at a population of 19,200 (108.9 bu.) and decreased at higher populations—23,100 = 93.1 bu. and 27,200 = 83.0 bu. Highest yields were attained with about 4,000 more plants per acre when irrigated than when not irrigated—23,100 vs 19,200 plants per acre. Stalk lodging. There tended to be slightly more lodging with irrigation than without irrigation in 1972 and in 1971. The reverse, more lodging when not irrigated, occurred during the previous three years, 1968-1970. Moisture content of grain at harvest. The effect of either irrigation or plant population on grain moisture was small during the five years. Irrigated corn averaged 0.7% higher moisture. Population of 23,100 and 27,200 averaged about .7% higher moisture than population of 15,100 and 19,200. Table 1 Hybrid (Brand--------- Variety) Michigan 200 (4X) Michigan 250 (4X) Michigan 275-2X(2X) Michigan 280 (4X) Michigan 300 (4X) Pioneer 3853 (4X) Super Crost S14 (2X) Acco UC1900 (2X) Jacques JX863 (2X) Michigan 333-3X (3X) 23.9 25.7 26.2 26.2 26.4 23 25 25 25 25 -- 27.5 -- 27.6 27.8 26 28.0 -- 28.0 27 -- Northrup King PX476(3X) 28.2 Funk Bros. G4180 (3X) 28.2 26 Funk Bros. G4263 (3X) 28.3 26 Cowbell SX002 (2X) 28.5 27 Northrup King PX20 (2X) 28.6 27 Michigan 396-3X (3X) Blaney B-302 (2X) Funk Bros. G4252 (3X) DeKalb XL304 (3X) Cowbell SX102 (2X) 28.6 27 28.7 -- -- 29.2 29.2 -- 27 29.4 Michigan 400 (4X) Mich. Exp. 70-21479-CB (2X) Mich. Exp. 71-2001(2X) Mich. Exp. 71-2001A(2X) Mich. Exp. 69-2223 (2X) 29.4 27 -- 29.6 -- 29.8 -- 29.9 30.0 -- 21 24 24 24 24 -- -- -- -- -- -- -- -- -- 25 26 -- -- -- 26 26 -- -- -- -- 98.5 108.3 126.3 136.6 138.4 90.5 101 98.2 123 99.9 137 123.4 145 145 126.9 -- 153.4 128.5 103.4 112.1 112.0 145.0 136.1 95.4 -- 99.5 136 90.3 -- -- 156 124.0 144.2 130.4 120.3 135 158.1 157 144 147.7 157.1 134.8 158 145.6 123.9 153.0 146.9 138.6 129.3 -- 156.1 128.3 -- 105.7 -- 127.7 125.2 135.1 142.1 129.8 167 141 142 -- 126.1 132.7 156.2 134.4 -- 148.5 124.3 -- 137.1 128.1 -- Montcalm County Trial-Irrigated vs Not Irrigated NORTH CENTRAL MICHIGAN One, Two, and Three Year Averages - 1972, 1971, 1970 % Moisture % Moisture % 2 Yrs 1972 Bushels Moisture3 Yrs Per Acre 1972 Irrig Bushels Bushels Per Acre 2 Per Acre 1972 Not Irrig Years Irrig Bushels Per Acre 2 Years Not Irrig Bushels Per Acre3 YearsIrrig Bushels Per Acre 3 Years Not Irrig % Stalk Stalk Lodging1972Irrig 62 61 65 75 76 68 89 77 90 79 78 83 81 78 -- -- -- -- -- -- -- -- -- -- -- 109 128 138 145 142 -- -- -- -- -- 154 166 143 141 -- -- -- -- -- -- -- -- -- -- -- 71 77 76 82 84 -- -- -- -- -- -- 90 96 90 86 -- -- -- -- -- -- -- -- -- -- 14.1 13.7 15.5 12.7 17.0 15.8 17.0 24.4 29.7 10.7 12.5 20.0 11.1 11.6 10.1 5.8 2.9 10.9 15.1 10.9 10.2 9.0 0.8 5.4 8.6 Lodging 1972 Not Irrig 3.2 12.3 1.5 12.4 8.1 -- 2.2 10.3 -- 14.5 23.8 -- 2.2 -- 2.1 6.9 3.6 4.3 7.5 4.3 8.6 -- 1.5 16.7 -- 5.0 9.1 -- 8.0 1.5 -- 2.2 0.0 % % Stalk Lodging 2 Zone 3 % Stalk Lodging 2 Years Not Irrig % Stalk Lodging3 YearsIrrig % Stalk Lodging 3 Years Not Irrig 2 8 1 7 5 7 1 5 2 3 4 3 -- 3 5 -- -- -- -- -- -- -- -- -- -- 10 12 9 9 9 -- -- -- -- -- 6 5 -- 7 7 -- -- -- -- -- -- -- -- -- -- 3 8 3 8 6 -- -- -- -- 3 2 4 4 -- -- -- -- -- -- -- -- -- -- -- -- Years Irrig 14 13 11 10 11 14 6 15 8 7 6 6 -- 9 11 -- -- Table 1 continued Pioneer 3909 (2X) DeKalb XL15A (2X) Mich. Exp. 69-3399 (3X) Pioneer 3784 (2X) Michigan 410-2X (2X) 30.1 28 30.3 28 30.3 -- -- 28 -- 30.5 30.5 29 -- Acco UC2301 (2X) Migro M-1101 (2X) Pioneer 3937 (3X) *Funk Bros. G4343 (2X) Blaney B-55A (3X) 28 30.5 -- 30.6 30.8 -- -- 30.8 30.9 28 DeKalb XL24 (2X) Northrup King PX519 (Sp.) 31.0 Jacques JX162A (2X) 31.1 Cowbell SX112 (2X) 31.1 Super Crost 1712 (2X) 31.2 31.0 29 **Michigan 572-3X (3X) 31.2 29 -- Acco U334 (3X) 31.2 Northrup King PX529 (3X) 31.2 -- 31.4 29 31.4 -- Northrup King PX556(3X) 31.5 -- **Pride R290 (2X) Pride R501 (3X) -- -- 30 -- -- -- -- 27 -- 28 -- -- -- -- 28 -- -- -- -- 28 -- -- 143 154 136.8 127.1 135.5 122.7 169.8 148.7 -- 155.0 127.6 170 154.6 177 143.5 162.7 146.2 171 137.6 -- 151.5 121.7 -- 150.7 175.0 142.3 -- 123.1 111.3 141 161 172 184 169.7 142.1 136.2 -- 144.4 158.4 127.2 170.3 140.1 -- 155.3 138.7 -- 186.3 156.5 131.9 -- 163.9 159.1 131.5 -- 178.4 164.4 182 131.3 -- 158.7 120.8 -- 149.6 198.3 169.4 -- 191.6 166.7 146.0 -- 172.8 117.2 -- 141.2 -- 190 165.8 134.9 156.6 146.2 171 -- 167.8 141.7 154.0 140.7 -- 156.9 -- 181.9 80 76 70 87 83 66 89 81 91 92 102 90 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 87 -- -- 100 -- -- 96 -- 101 94 148 -- 183 -- 159 -- 180 -- 156 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 5.8 20.9 6.7 7.1 6.4 12.9 3.0 7.3 8.8 5.1 8.1 2.2 14.7 19.4 8.6 10.0 9.8 11.6 10.4 9.2 6.4 7.1 8.0 14.3 9.4 9.0 9.6 18.0 13.1 11.7 3.7 12.5 2.9 -- 2.9 3.0 5 14 5 8 5.8 0.7 -- 2.9 -- 1.5 -- 0.0 6.5 6.1 -- 4.5 2.9 -- 2.2 4.5 1.5 -- 4.3 -- 8.9 0.7 -- 5.9 -- -- 3.0 0.0 5.4 -- 2.2 -- -- 10 7 7 15 -- 7 10 7 6 3.8 7.2 9.3 17.9 1.4 -- -- -- 2 6 2 2 3 1 4 3 -- 3 5 0 5 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 4 -- 6 -- 5 -- --] 7 5 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 3 1 4 4 5 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- **Mich. Exp. 71-2002 (2X) **Mich. Exp. 69-3097(3X) *Mich. Exp. 69-3021 (3X) Pioneer X8351 (2X) Blaney B-501A (2X) Blaney B-AA (2X) Mich. Exp. 70-21259-CB (2X) Pioneer 3773 (2X) **Pioneer 3780 (2X) 31.6 31.7 31.8 31.9 -- -- 30 -- -- -- 31.9 32.0 29 -- 32.0 32.0 -- 32.3 -- -- -- -- -- 27 -- -- -- Table 1 continued Renk RK9 (Sp.) Pioneer 3729 (3X) **Blaney BX-AA (2X) **Michigan 511-3X(3X) **Funk Bros. G4444 (2X) 30 32.3 32.6 -- 32.6 31 32.8 31 32.9 -- **Northrup King PX47E(2X) 33.0 -- 33.0 -- 33.0 30 31 33.4 33.4 -- **Michigan 500-2X (2X) *Mich. Exp. 67-1932 (2X) **Acco UC3301 (2X) Acco UC3300 (2X) **Michigan 560-2X(2X) **Mich. Exp. 67-3124 (2X) **Mich. Exp. 71-2003 (2X) *Acco UC3201 (2X) **Super Crost S27 (2X) **P.A.G. SX69 (2X) **Super Crost S25 (2X) Average Range -- 33.4 33.5 32 33.5 -- -- 33.7 34.0 31 34.1 35.6 30.6 23.9 to 35.6 31 31 28 23 to 32 -- -- -- -- -- -- -- 29 -- -- -- -- -- -- -- -- -- 26 21 to 29 177.9 154.5 181 142.0 122.8 -- 188.5 172.8 199 203.8 163.3 200 145.2 135.4 -- -- 159.3 187.2 139.1 128.9 -- 178.2 159.3 181 178.5 142.0 183 -- 182.7 149.8 -- 187.8 162.1 206.3 179.1 175.5 149.9 -- 143.7 -- 172.3 172.7 160.7 208 180 201.7 185.4 161.4 195 152.2 187 157.3 136.6 163 98.5 to 206.3 90.5 to 179.1 101 to 208 -- -- -- -- -- -- -- 93 101 99 94 87 -- 109 94 96 84 84 61 to 109 -- -- -- -- -- -- -- -- -- -- 177 -- -- -- -- -- -- 151 109 to 183 -- -- -- -- -- -- -- -- -- -- -- 105 -- -- -- -- -- 89 71 to 105 Least significant difference1.1 0.7 0.5 14.4 12.5 7 6 5 5 * Significantly better than average yield, irrigated, 1972 ** Significantly better than average yield, not irrigated, 1972 5.8 14.6 5.8 5.8 2.2 3.0 7.9 6.6 3.6 3.6 5.8 3.7 5.9 2.9 7.4 3.4 6.7 9.7 7.2 14.1 4.3 6.5 4.4 -- -- 2.2 7.9 0.7 3.1 2.9 -- 9.4 3.3 3.5 3.6 -- 2.2 0.8 8.8 5.6 5 -- 4 6 -- 7 4 -- 5 -- 5 4 6 8 -- -- -- -- 4 -- 2 4 -- 0 3 -- 2 -- 2 0 5 3 -- -- -- -- -- -- -- -- -- -- 5 -- -- -- -- -- -- 7 -- -- -- -- -- -- -- -- -- -- 1 -- -- -- -- -- -- 4 0.8 to 29.7 0.0 to 23.8 empty table cell 4 to 15 0 to 8 4 to 12 empty table cell 1 to 8 empty table cell empty table cell empty table cell empty table cell Table 1 continued empty table cell Planted Harvested Soil type Previous crop 1972 May 5 Oct. 25 Population Rows Fertilizer Soil test: pH : P Soil test Soil test: K Irrigation Sorghum-sudan seeded to rye in fall 20,100 30” 258-145-145 5.5 420 (very high) 178 (medium) 6" Montcalm sandy loam Montcalm sandy loam 1971 May 6 Oct. 29 Sorghum-sudan seeded to rye in fall 20,300 30” 160-140-140 6.0 340 (very high) 246 (high) 12.5” 1970 May 8 Oct. 16 Montcalm sandy loam Sorghum-sudan seeded to rye in fall 19,900 30" 213-160-160 6.3 246 (very high) 255 (high) 5.5" Farm Cooperator: Theron Comden, Lakeview County Extension Director: James Crosby, Stanton Table 2. Average, highest, and lowest yields and percent stalk lodging for corn hybrids irrigated and not irrigated for five years, 1968-1972. Highes Highes t No t Irrigated Lowes t Irrigated Lowes t Not Irrigated Year No. of hybrid s tested Averag Averag e No e Irrigated t Irrigated 72 56 64 63 56 157.3 162.5 143.6 146.0 136.1 1972 1971 1970 1969 1968 Averageempty table cell % Stalk Lodging% Stalk Lodging% Stalk Lodging 149.1 136.6 28.2 102.9 85.5 96.0 89.8 t Irrigated 206.3 210.5 193.8 184.9 182.2 195.5 179.1 41.9 127.7 108.6 123.2 116.1 98.5 91.0 94.9 96.7 92.2 94.7 90.5 10.6 69.6 56.3 65.4 58.5 % Stalk Lodging% Stalk Lodging% Stalk Lodging % Stalk Lodging % Stalk Lodging 72 56 64 63 56 1972 9.7 1971 7.4 1970 5.8 1969 2.9 1968 1.1 Averageempty table cell 5.3 5.6 0.9 7.1 17.5 4.3 7.1 Irrigation: 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" 29.7 23.4 18.3 10.9 5.0 17.5 23.8 3.1 24.4 57.8 13.9 24.6 1970 = 5.5" July 20 = 1" July 27 = 1" July 30 = .5" Aug. 4 = 1" Aug. 11 = 1" Aug. 13 = 1" 0.8 1.5 0.0 0.0 0.0 0.5 0.0 0.0 0.0 5.6 0.0 1.1 1969 = 6" July 26 = 1.5" Aug. 8 = 1.5" Aug. 14 = 1.5" Aug. 27 - 1.5" Table 3. Average yield and percent stalk lodging at four plant populations irrigated and not irrigated for five years, 1968-1972. 15,10 15,10 0 No t Irrigated 19,20 19,20 0 No t Irrigated 23,10 23,10 0 No t Irrigated 27,20 27,20 0 No t Irrigated % Stalk Lodging % Stalk Lodging 10.3 6.4 2.9 2.4 0.6 4.5 7.6 1.0 8.0 18.5 3.3 7.7 % StalkLodging % Stalk Lodging % StalkLodging 12.3 7.8 5.8 2.7 0.4 5.8 9.1 0.6 9.1 23.4 5.1 9.5 18.1 10.7 8.4 3.4 2.7 8.7 % Stalk Lodging % Stalk Lodging % Stalk Lodging 16.2 0.9 10.6 28.0 12.1 13.6 23.1 10.1 9.4 5.2 3.4 10.2 19.8 1.5 11.5 34.4 20.4 17.5 0 Irrigated 151.9 172.9 122.2 125.5 143.5 143.2 132.4 36.6 91.0 90.7 113.9 92.9 0 Irrigated 186.5 189.1 144.1 157.5 169.3 169.3 158.8 35.3 111.7 108.5 130.2 108.9 0 Irrigated 191.2 190.9 158.2 173.2 193.1 181.3 149.3 20.2 93.4 95.7 107.0 93.1 0 Irrigated 161.2 180.6 151.2 147.8 178.4 163.8 143.9 10.5 85.1 86.3 89.4 83.0 Year 1972 1971 1970 1969 1968 Average % Stalk Lodging 1972 1971 1970 1969 1968 Average