• Alfalfa Varieties from the 1920s to the 1980s: Comparison of Forage Yield During the Seedling Year

      Smith, S. E.; Conta, D. M.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
    • Alfalfa Variety Demonstration at the Safford Agricultural Center, 1984-87

      Clark, L. J.; Cluff, R. E.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      Twenty non - and very non - dominant alfalfa varieties were compared over three seasons. The top - yielding variety, Pioneer 5929, has maintained this position for the last three years. The yields decreased considerably from the previous year, however. Part of the loss can be attributed to the sacrifice of the first cutting because of damage by the Egyptian alfalfa weevil. Pioneer 5929 was the top -yielding variety during the entire trial, producing more than 30 tons per acre. Four other varieties produced more than 28 tons per acre: Ardiente by Agripro; Pierce by Northrup King, Palmer Special by the Palmer brothers of Graham county; and Safford 80 LH.
    • Alfalfa Variety Trial in Greenlee County, 1987

      DeRosa, E.; Clark, L.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      Ten alfalfa varieties ranging from very non - dormant to moderately dominant were compared over two seasons. Significant differences were observed between yields of top varieties from 1986 to 1987. Baron, the highest yielding variety for 1986 ranked 3rd in 1987, with Valiant moving from seventh to first in 1987. Overall yields increased from seven tons in 1986 to almost eleven tons per acre in 1987. The previous county average was 5.5 ton per acre.
    • Barley Response to Water and Nitrogen, 1988

      Roth, B.; Gardner, B.; Tickes, B.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      Results from 1988 show that yields of 3.9 and 3.7 tons per acre are feasible for Gustoe and NKX -1558 barley cultivars. The short season cultivar Barcott yielded about one ton less. The predicted optimum amounts of water and nitrogen were approximately 30 inches and 150 pounds per acre, respectively.
    • Barley Variety Trial at the Safford Agricultural Center, 1988

      Clark, L. J.; Carpenter, E. W.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      Nine varieties of barley were tested at the Safford Agricultural Center in response to growers' requests for high yielding barley varieties with the potential to mature more quickly than Gustoe. Gustoe was the top- yielding variety with 5,551 pounds per acre. A University of California variety was a close second but it has the same maturity as Gustoe. The varieties that mature more quickly, Barcott and Fiesta, yielded approximately 1,500 pounds fewer than Gustoe.
    • Barley Variety Trial in Cochise County, 1988

      Clark, L. J.; Schwennesen, E.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      Eight barley varieties were tested in a replicated variety trial in northern Cochise county. These varieties varied from relatively early maturing varieties, such as Barcot4 to the longer maturing varieties, such as Gustoe. The medium -late variety, Northrup King 1558, was the top - yielding variety, with 7,185 pounds per acre. This exceeded the yield of the standard variety, Gustoe, by 15 percent, making NK 1558 a variety that should be looked at further. It will be marketed by Northrup King under the name Sunbar 458.
    • Bermuda Grass insect Control

      Tickes, B.; Rethwisch, M.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
    • Breeding Strategies for Alfalfa Grown Under Saline Conditions

      Johnson, D. W.; Smith, S. E.; Dobrenz, A. K.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
    • Comparison of Residual Nitrate and Fertilizer Nitrogen Efficiency in Basin Irrigated Wheat

      Doerge, T.; Knowles, T.; Ottman, M.; Clark, L.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      The relative efficiencies of residual soil NO₃⁻N and fertilizer Nin basin - irrigated wheat production are not well defined. A two-year field study was conducted at the Safford Agricultural Center to investigate what these N efficiencies are under optimum yielding conditions. 'Aldura' durum wheat was grown on the same field site two years in succession. In 1987 a wide range of fertilizer N (0 to 419 lbs /A) applications resulted in residual NO₃⁻N accumulations of 36 to 140 lbs /A in the surface four feet of soil. Residual N plots were split in 1988 with one subplot receiving no additional N while the other was treated with 145 lbs of fertilizer N /A. Grain yield response curves for the –N and +N subplots were used to estimate the marginal rate of substitution (MRS) of soil NO₃⁻N for fertilizer N. The marginal efficiency of residual NO₃⁻N was a constant 16.7 lbs. grain produced /lb. of N across the range of profile N values in this study, while the marginal efficiency of fertilizer N varied from over 17 to below 6 lbs. grain /lb. N. When basin- irrigated wheat is supplied with adequate, but not excessive N, the MRS of soil vs. fertilizer N is about 1:1 although absolute N efficiencies under basin irrigation are considerably lower than those achieved in other grain production systems.
    • Corn Variety Trial in Bonita, Cochise County, 1987

      Clark, L. J.; Schwennesen, E.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      The 1987 trials included 14 commercial corn hybrids, which were tested on a heavy - textured soil in northern Cochise county; they were the better yielding hybrids from the previous trial. Five new entries, not previously tested in Cochise county, were included. Garst 8345, one of the new entries, was both the top - yielder, at 12,499 pounds per acre, and the hybrid producing the highest adjusted gross income per acre. Hybrids produced by Pioneer, Cargill, DeKalb and NC+ seed companies all yielded more than 12,000 pounds per acre.
    • Corn Variety Trial in Greenlee County, 1987

      DeRosa, E.; Clark, L.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      Fifteen varieties of about 125+ day corn hybrids were tested in an ongoing variety trial in Greenlee County.
    • Cultural Practices of One-Irrigation Barley at Marana, 1988

      Ottman, M. J.; Ramage, R. T.; Thacker, G. W.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      One-irrigation barleys were bred to be grown with only a single irrigation near planting time. To further our understanding of how to manage these new cultivars, two one - irrigation barley genotypes (Seco and 2 -22 -9) were grown at four seeding rates (20, 40, 60, and 80 lbs seed /A); four nitrogen rates (0, 50, 100, and 150 lbs N /A); two phosphorus rates (0 and 100 lbs P₂O₅ /A); four row spacings (6, 12, 18, and 24 inch); and three planting dates (Nov 19, Dec. 23, and Jan. 22). The optimum seeding rate, fertilizer rate, and row spacing were dependent on genotype and planting date. The optimum seeding rate was 40 to 60 lbs /A for Seco and 80 lbs /A for 2 -22 -9. An increase in seeding rate decreased kernel weight and kernel number per head but increased head number. A positive response to nitrogen fertilizer was not obtained due to the high levels of residual soil nitrogen at planting (20 ppm NO₃⁻N) except for the case of Seco at the Dec. 23 planting date. Phosphorus fertilizer increased yield only at the Nov. 19 planting date and if accompanied by 100 lbs N /A. Soil phosphorous levels were 2 ppm PO₄⁻P and a positive response was expected Kernel weight was not influenced by Nor P fertilizer. Kernel number per head increased with certain combinations of genotype and planting date. Head number decreased with N rate but increased with phosphorus. The optimum row spacing was 18 inches at the Nov. 19 planting and 12 inches for Seco at the Jan. 22 planting date. At other combinations of genotype and planting date, no differences in grain yield were detected due to row spacing. Kernel weight increased with row spacing at the Nov. 19 planting date; kernel number per head was generally not affected and, head number decreased with row spacing. The results of this study surest that any recommendations on how to grow one - irrigation barley are gross approximations because of variations due to year, planting date, and genotype.
    • Development of Grazing-tolerant Alfalfa for the Southwest

      Smith, S. E.; Rodrigues, G. H. S.; Conta, D. M.; McKinley, L.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
    • Double Crop Grain Sorghum Variety Trial in Graham County, 1987

      Clark, L. J.; Cluff, R. E.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      1987 was a better year for double -crop grain sorghum than the previous year. The yields increased to nearly a ton per acre. The top - yielding variety was Asgrow Topaz at 7,885.7 pounds per acre. This yield topped the standard variety, DeKalb 64 by almost 4 percent. Bird damage was also reduced this year.
    • Durum Seeding Methods, 1988

      Ottman, M. J.; Harper, J.; Tickes, B.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      WestBred 881 durum commands a premium price due to its superior quality, but it produces a lower yield than other commercially available cultivars. Studies conducted at Maricopa in 1987 suggested that yields of WestBred 881 may be increased by 3-inch row spacing. Studies were conducted at three commercial farms in an effort to mimic the effect obtained with 3-inch row spacing by using conventional grain drills to obtain more uniform plant spacing. Seeding twice in parallel directions did not result in the desired effect because the seed planted in the first pass was covered by extra soil from the second pass, and the seedlings emerged from cracks made by the disk openers from the second pass. Broadcasting on beds resulted in a poor stand and non- uniform plant distribution compared to drilling the beds. Planting twice in perpendicular directions to each other resulted in a more uniform plant distribution than drilling once, but a slightly poorer stand was achieved due to extra wheel traffic and yields were not significantly increased. The best method to obtain a more uniform plant spacing may be to seed with a 3-inch drill.
    • Effect of Russian Wheat Aphid on Durum Wheat Yield

      Dick, G.; Harper, J.; Moore, L.; Ottman, M.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
    • The Effects of Alfalfa Seed Scarification in Saline Environments

      Poteet, D. C.; Robinson, D. L.; Dobrenz, A. K.; Smith, S. E.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      The handling of alfalfa and other crop seed may result in seed scarification. Scarification may not affect germination of alfalfa seed in a non - saline environment, but may decrease germination where farmer's fields are severely salt-stressed.
    • Effects of P Applications on Wheat Tissue Phosphate Levels and Grain Production in Graham County

      Knowles, T.; Doerge, T.; Ottman, M.; Clark, L.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      Collecting additional data to calibrate and refine current guidelines for interpreting soil and plant test values for P is an ongoing need in Arizona. An experiment was conducted at the Safford Agricultural Center during the 1987 -88 crop year to evaluate the response of 'Aldura' durum wheat to P fertilizer applications on a clay loam soil testing low in available P. Maximum grain yields of more than 5,500 lbs. /A were obtained by banding 40 lbs. P₂O₅/A as triple super phosphate with the seed at planting. A December 9 planting date subjected plants to cold soil temperatures early in the season (up to 80 days after planting), rendering soil P less available for plant utilization. Preplant soil P analyses predicted the yield increase observed with P fertilization (11.2 %);however, economic returns were not sufficient to offset the cost of P fertilizer. The recommended preplant soil test for P proved accurate in predicting P status and stem PO₄⁻P tissue analyses seemed reliable in monitoring P nutrition of durum wheat. A critical nutrient range of 1200 - 2000 ppm PO₄⁻P is proposed for basal stem tissue sampled prior to the joint growth stage, and 1500 - 1706 ppm PO₄⁻P is suggested for flag leaf tissue sampled at the boot stage.
    • Effects of Salinity on the Water Potential of Alfalfa Seedlings

      McKimmie, T.; Dobrenz, A. K.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      Alfalfa seedlings were grown under saline conditions for six weeks and separated into two populations, based on height. Water potential was measured on roots, stems, leaves, and petioles of tall and short plants. Tall plants had a higher water potential for each plant part.
    • Evaluation of Plant Growth Regulators on Wheat in Arizona, 1987

      Tickes, B.; Ottman, M. J.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1988-09)
      Plant growth regulators are applied to small grains to decrease lodging which can adversely affect crop growth and yield. Wheat is intensively managed in Arizona, and lodging can be a problem. Chlormequat and ethephon were applied at various rates and times in six studies in 1987 to evaluate their use on Arizona's semi -dwarf cultivars with respect to lodging plant height, yield components and grain yield The results indicated that growth regulators applied at the recommended rates and times may decrease plant height and decrease kernel weight. However, the influence of growth regulator treatments on tiller number, head number, kernel number, and grain yield was not demonstrated. The ambiguous results obtained suggest our efforts need to be directed toward documenting the extent of lodging in the state, studying the effects of lodging and predicting when lodging will occur.