• Improved Regrowth Salt Tolerance in Alfalfa

      Johnson, D. W.; Smith, S. E.; Dobrenz, A. K.; Ottman, Michael; Kingdon, Lorraine (College of Agriculture, University of Arizona (Tucson, AZ), 1989-09)
    • Interpretation of Basal Stem Nitrate-N Concentrations for Improved Nitrogen Management in Irrigated Durum Wheat Production

      Knowles, T.; Doerge, T.; Ottman, M.; Ottman, Michael; Kingdon, Lorraine (College of Agriculture, University of Arizona (Tucson, AZ), 1989-09)
      Attempts to characterize nitrogen (N) status of irrigated spring wheat by using basal stem nitrate - N (NO₃⁻N) tissue tests have shown contradictory results, due to the wide range of agronomic conditions existing in Arizona. Seven N fertility trials were conducted at the Maricopa and Safford Agricultural Centers over the 1985-88 crop years to examine the effects of N rate, N fertilizer form, residual soil N, soil texture and contrasting varieties on basal stem NO₃⁻N concentrations, yield and quality of irrigated durum wheat. Fertilizer N treatments were broadcast at planting then at the 5-6 leaf, boot and anthesis growth stages to simulate fertigation in conjunction with the first four basin irrigation events. Stem tissue samples were taken from all plots at the 3-4 leaf 5-6 leaf joint, boot and anthesis growth stages for NO₃⁻N analysis with a nitrate electrode. Diagnostic levels for durum wheat basal stem tissue NO₃⁻N tests at these growth stages are presented.
    • Oat Variety Grain and Forage Yield Trials at the Maricopa Agricultural Center 1989

      Sheedy, M.; Ottman, M.; Ramage, T.; Ottman, Michael; Kingdon, Lorraine (College of Agriculture, University of Arizona (Tucson, AZ), 1989-09)
    • Pinto Bean Variety Trials in Graham and Greenlee Counties, 1988

      Clark, L. J.; DeRosa, E.; Schwenneson, E.; Cluff, R. E.; Ottman, Michael; Kingdon, Lorraine (College of Agriculture, University of Arizona (Tucson, AZ), 1989-09)
      Two pinto bean variety trials were grown in Greenlee and southern Graham counties. UI 114, the most commonly grown variety in both areas, was out yielded in both locations by other varieties. In Greenlee county, Luna, a New Mexico variety, surpassed UI 114 by approximately 100 pounds per acre. In Graham county, Olathe, a Colorado variety, out yielded UI 114 by more than 250 pounds per acre. At $40 per hundredweight, the latter difference translates into more than $100 per acre.
    • Possible New Annual Leguminous Forages for Arizona

      Smith, S. E.; Graves, W. L.; Conta, D. M.; Ottman, Michael; Kingdon, Lorraine (College of Agriculture, University of Arizona (Tucson, AZ), 1989-09)
    • Progress in the Development of Salt Tolerance in Alfalfa

      McKimmie, T.; Dobrenz, A. K.; Malchow, P. L.; Ottman, Michael; Kingdon, Lorraine (College of Agriculture, University of Arizona (Tucson, AZ), 1989-09)
      Increasing crop salt tolerance can mean higher yields on irrigated farmland and salt -affected soils. Three cycles of selection were made for growth of alfalfa seedlings under 7500 ppm NaCl. Comparison of parent and selected populations was made for yield and germination under saline conditions. Yield of the last cycle was significantly improved. Germination of the last two cycles was higher than that of the parent and cycle 1.
    • Small Grain Variety Comparisons at the Maricopa Agriculutral Center, 1989

      Sheedy, M.; Ottman, M.; Ramage, T.; Ottman, Michael; Kingdon, Lorraine (College of Agriculture, University of Arizona (Tucson, AZ), 1989-09)
    • Variability in Salt Tolerance within a Population of Alflafa

      McKimmie, T.; Dobrenz, A. K.; Ottman, Michael; Kingdon, Lorraine (College of Agriculture, University of Arizona (Tucson, AZ), 1989-09)
      Genetic variability must exist for a selection program to be successful. Alfalfa seedlings were selected for salt tolerance after six weeks growth at 7500 ppm NaCl. The selection criteria considered plant height and survival. Variability for each factor within a population of alfalfa was shown. Both criteria were important and facilitated selection from those parents which contributed most to the salt tolerance of the population.
    • Wheat and Durum Variety Trial in Poston, 1989

      Winans, S. S.; Ottman, M. J.; Doerge, T. A.; Ottman, Michael; Kingdon, Lorraine (College of Agriculture, University of Arizona (Tucson, AZ), 1989-09)
    • Wheat Irrigation Scheduling at the Safford Agricultural Center, 1989

      Clark, L. J.; Carpenter, E. W.; Ottman, Michael; Kingdon, Lorraine (College of Agriculture, University of Arizona (Tucson, AZ), 1989-09)
      Wheat irrigations were scheduled using two computer models and an infrared thermometer, using three critical threshold values. Yields from these plots were compared with plots scheduled by the farm manager. The highest yield was obtained by the computer model using evapotranspiration data taken from the local AZMET station; this corroborates results from the previous year. The crop coefficients and the irrigation model that have been developed over the past several years are very accurate for this area. The two lower threshold infrared treatments were second and third in yield and had lower water use efficiencies.