• The Effect of Gypsum and Sulfuric Acid Soil Amendments on the Yield of Alfalfa and Soil Infiltration Rates: A Progress Report

      Harper, John; Watson, Jack; Doerge, Tom; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Oat Hay Variety Evaluation

      Harper, John; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Seeding Rate and Row Spacing for Westbred 881 and Aldura Durum Wheat at Maricopa, 1987

      Ottman, Mike; Day, Arden; Harper, John; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Westbred 881 durum wheat commands a premium price due to its superior quality, but produces a lower yield than other commonly grown commercial cultivars. This study was initiated to improve our understanding of how best to manage Westbred 881. Two durum wheat cultivars (Westbred 881 and Aldura) were planted at 5 seeding rates (30, 60, 120, 180, and 240 lbs. seed/A), 5 row spacings (3, 6, 12, 18, and 24 inches), and two planting dates (Dec. 1 and Jan. 16) at the Maricopa Agricultural Center. Both cultivars produced optimum yields at seeding rates of 120 to 180 lbs/A for the Dec. 1 planting date. At the Jan. 16 planting date, however, yields of Westbred 881 increased linearly with seeding rate up to 240 lbs/A, while Aldura produced optimum yields between 120 and 180 lbs. seed/A. At the Dec. 1 planting date, Aldura produced similar yields at row spacings from 3 to 12 inches, while the yield of Westbred 881 decreased linearly with an increase in row spacing. The highest yield achieved in this study was with Westbred 881 at the 3 -inch row spacing. Row spacings of 6 to 12 inches were optimum for both Westbred 881 and Aldura at the Jan. 16 planting date. The seeding rate and row spacing responses attained with Westbred 881 may be related to its tittering characteristics.
    • 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.
    • Yield Comparisons of Alfalfa Cultivars and Experimentals at Maricopa and Yuma, 1986 to July 1987

      Ottman, Mike; Smith, Steve; Tickes, Barry; Harper, John; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      This study is part of an ongoing effort on evaluate alfalfa cultivar performance at various locations in Arizona. Forage yields of 25 alfalfa cultivars and experimentals were measured at the Maricopa and Yuma -Mesa Agricultural Centers. During the time period reported, many of the newer cultivars were more productive than the popular cultivar CUF 101 . Selection of alfalfa cultivars should be based upon fall dormancy, pest resistance, seed cost, and yield potential.