• Yield and Water Use of Barley Cultivars Compared Under an Irrigation Water Gradient at Marana, 1987

      Ottman, Mike; Ramage, Tom; Brown, Paul; Thacker, Gary; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      This study was initiated to determine how barley cultivars perform outside the environment for which they were selected. Also, a comparison was made of water use by a one-irrigation barley with water use of a commercial cultivar selected for high yield conditions. Six barley cultivars bred for differing growing conditions (Westbred Gustoe and Westbred Barcott - high input; Arivat and Prato - medium input; and, Seco and 2-22-9 - low input) were compared under 12 water regimes delivered by a line -source sprinkler system. Water use of Seco, a one-irrigation barley, and Westbred Gustoe, a commercial barley, was monitored with a neutron probe. The barley cultivars bred for high, medium, and low input conditions performed best in their respective optimum water levels with the exceptions of Westbred Barcott and Prato. Westbred Barcott (high input) yielded relatively well over all water levels, and Prato (medium input), performed similar to a high input barley. Seco (low input) used slightly less water than Westbred Gustoe (high input), primarily due to its earlier maturity. The water extraction pattern with depth was similar for both cultivars due to the frequent shallow irrigations applied in this study. The water extraction pattern of Seco needs to be investigated under one- irrigation conditions.
    • Yield and Water Use of Wheat as Influenced by Early Irrigation at Maricopa, 1987

      Ottman, Mike; Brown, Paul; Harper, John; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      When the first irrigation in wheat is applied early, it is usually done to bank or save water for later in the season. On the other hand, when the first irrigation is applied late, it is done to force deep rooting. The objective of this study was to determine the influence of an early irrigation and an early stress period on yield and water use of two durum wheat cultivars when subjected to water stress during the grain fill period. Grain yield of Westbred 881 was not influenced by irrigation treatment, but the grain yield of Aldura was higher with early irrigation rather than early stress. Part of this response may be explained by the poorer stand and the lower stem number of Aldura compared to Westbred 881 under early stress conditions. Water use later in the season was unaffected by irrigation treatment. Early irrigation did not save water for later in the season, and early stress did not improve the plant's ability to extract deep moisture under the conditions of this study.