• Irrigation Scheduling on Long and Short Staple Cotton Safford Agricultural Center, 1990

      Clark, L. J.; Carpenter, E. W.; Scherer, T. F.; Slack, D. C.; Fox, F. Jr.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1991)
      Three irrigation scheduling techniques are compared on both long and short staple cotton in replicated small plot trials on the Safford Agricultural Center. The Erie method uses historical evapotranspiration data developed in the Mesa area but mathematically adjusted for the elevation in Safford and incorporated in a computer spreadsheet. The AZSCHED method is a near real -time irrigation scheduling program using AZMET weather date, a modified Penman equation and heat unit based crop coefficients to calculate water deficits. This program will schedule irrigations on up to 60 fields. The third method utilizes infrared thermometry to determine crop water stress indices from foliage temperatures, ambient temperature and relative humidity. This latter method was used to track the crop stress throughout the growing season on all treatments. All three methods were considered successful for both long and short staple cotton with the Erie method yielding higher than the other two for both types of cotton. Further refinements will be made on the AZSCHED method until it performs at or above the Erie method