• Response of Barley and Wheat to Sewage Sludge Loading Rates

      Day, Arden; Solomon, Mengste; Taylor, Brooks; Pepper, Ian; Minnich, Martha; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      A greenhouse experiment was conducted to evaluate the responses of barley and wheat to sewage sludge loading rates of 150 to 750 lb /acre plant-available N and to recommended inorganic N (150 lb/ acre). All sewage sludge rates delayed maturity in both barley and wheat. Sludge loading rates up to 450 lb /acre of plant-available N increased vegetative growth and grain yield in both crops. Sludge rates higher than 450 lb/acre of plant-available N resulted in a reduction in the number of plants per pot; however, the stand reduction was greater for wheat than for barley.
    • Russian Wheat Aphid, Diuraphis noxia (Mordvillko): A New Insect Pest of Small Grains in Arizona

      Dick, Gary; Moore, Leon; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Dryland Catchment Test Planted to Hybrid Sorghum and Pearl Millet in Avra Valley Near Three Points, 1986

      Thacker, Gary; Voigt, Robert; Schmalzel, Carl; Ottman, Mike; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Performance of Germination Salt Tolerant Alfalfa on a Non-Saline Site

      Smith, Steve; Conta, Debra; Dobrenz, Albert; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Small Grain Variety Comparisons at the Yuma Agricultural Center in 1987

      Thompson, Rex; Sheedy, Michael; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Barley Response to Water and Nitrogen Levels

      Roth, Bob; Gardner, Bryant; Tickes, Barry; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Results from one year's data show that yields of more than five tons per acre are feasible for Fiesta, Gustoe and NKX -1558 barley cultivars. The cultivar Barcott is a shorter season variety; yields were reduced by approximately one ton per acre, compared to the other cultivars. Additional data needs to be collected to verify the amounts of water and nitrogen required for obtaining optimum production.
    • Oat Hay Variety Evaluation

      Harper, John; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Wheat Germplasm Releases by the Agricultural Experiment Station in 1987

      Thompson, Rex; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Corn Variety Trial in Greenlee County, 1986

      Clark, Lee; DeRose, Edith; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Ten varieties of 115 to 125 day corn hybrids were tested in an on going variety trial in Greenlee county. Drying costs were also calculated to not only determine the top- yielding variety but also the variety having the highest net value after subtracting drying costs. Pioneer 3183 ranked top in both categories.
    • Inproved Nitrogen Management in Irrigated Wheat Production Using Stem Nitrate Analysis

      Doerge, Thomas; Knowles, Tim; Ottman, Mike; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      The method for predicting the nitrogen (N) requirements of irrigated wheat that is recommended by the University of Arizona requires preplant soil, plus mid-season stem nitrate analysis. Additional information on the relationships between N rates, stem NO₃-N levels and grain yields are needed for the wide range of agronomic conditions typical of Arizona's wheat growing areas. Three N fertility trials were conducted at the Maricopa Agricultural Center to, 1) measure the accuracy of the current University of Arizona procedure on soils of contrasting texture; 2) to evaluate the use of the current stem testing procedure on two durum varieties, "Aldura" and "Westbred-881"; and 3) to evaluate the effect of various N forms on the levels of NO₃-N in stem tissue for wheat grown in a clay loam soil. The University of Arizona procedure was found to over predict slightly the amount of N required for optimum economic return on sandy soils where the maximum yields obtained did not exceed 5100 lbs. grain/a which is considerably below the expected yield possibility for these sites. The procedure accurately predicted the amount of N required for optimum production on a clay loam soil (175 lbs. N/a)at a maximum yield of 6000 lbs. grain /acre. "Aldura" and "Westbred-881" were remarkably similar in their response to a wide range of N applications. There was no significant difference in the yields of these two varieties, but "Westbred-881" did contain somewhat higher protein levels. Little statistical or practical differences were observed in the quantities of N contained in the stem tissue of these two varieties; this should help simplify the interpretation of stem NO₃-N values for various wheat cultivars. The chemical form of N applied to wheat grown in a clay loam soil had no significant effect on the quantity of NO₃-N measured in stem tissue at any time during the growing season. The currently recommended procedure for predicting optimum N fertilization rates in wheat productions shows considerable promise but needs further evaluation, particularly under high - yielding conditions.
    • Water Stress Indices for Research and Irrigation Scheduling in Pearl Millet

      Teowolde, Haile; Voigt, Robert L.; Osman, Mahamoud; Dobrenz, Albert K.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      The capability to measure the magnitude of water stress in plants is useful for precision irrigation scheduling and other purposes. This paper reports an evaluation of leaf (TL) and canopy (Tc) temperatures, leaf minus air (TL -Ta) and canopy minus air (Tc -Ta) temperatures, and leaf water stress index (LWSI) and crop water stress index (CWSI) in detecting stress in pearl millet (Pennisetum americanum (L.) Leeke) over two growing seasons. Baselines which were used to compute LWSI and CWSI were obtained. The upper and lower baselines for the Tc data, respectively, were Tc -Ta = 4.10 C and Tc -Ta = 3.87- .2001VPD where VPD is vapor pressure deficit in mbars. For the TL data, the upper and lower baselines, respectively, were TL -Ta = 1.97oC and TL -Ta = 1.308- .03006VPD. Tests against photosynthesis, transpiration, and grain yield showed that LWSI and CWSI are better indices of stress than TL -Ta, Tc -Ta, TL, Tc, or Ta. Average seasonal LWSI and CWSI ranged from approximately 0.03 for non- stressed to 0.80 for stressed plants. The reliability of LWSI and CWSI to detect stress and their relation with grain yield suggested the possibility of using these indices for irrigation scheduling decisions.
    • Late Corn Variety Trial in Greenlee County, 1986

      Clark, Lee; DeRose, Edith; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Five corn varieties with maturities varying from 95 to 108 days were grown in a double crop situation following barley. The variety that produced the highest net value (after deducting drying costs) yielded only $194.39 per acre, slightly less than the marginal cost of production.
    • Wheat Variety Demonstration in Roll, 1987

      Tickes, Barry; Ottman, Mike; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Strain Crossing for Large-Leaflet Alfalfa: A First Look

      Dobrenz, Albert; Robinson, David; Smith, Steve; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Oxyflourfen (Goal) for Selective Control of Little Malva in Seedling Alfalfa

      Thacker, Gary; Heathman, Stan; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Little Malva (Malva porviflora L.) is an important weed that is resistant to herbicides that will selectively control most other broadleaf weeds in alfalfa. Oxyfluorfen (Goal) has been placed under an Experimental Use Permit for alfalfa. In 1987, this herbicide was evaluated for the selective control of malva in alfalfa in the Avra Valley west of Tucson. Oxyfluorfen stunted both the malva and the alfalfa. However, the alfalfa was stunted to a lesser degree, and had begun to recover three weeks after the application of oxyfluorfen. The malva did not recover, and the alfalfa was relieved from weed competition three weeks after treatment.
    • Effects of Sewage Sludge on Wheat Forage Production

      Day, Arden; Swingle, Spencer; Taylor, Brooks; Pepper, Ian; Minnich, Martha; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Experiments were conducted in Avra Valley, Arizona, to study the use of digested liquid sewage sludge as a source of plant nutrients in the commercial production of green-chopped feed and hay from wheat. Wheat grown with the recommended amount of plant-available nitrogen from sewage sludge produced more green-chopped feed and hay than did wheat grown with the same amount of nitrogen from inorganic fertilizer. Wheat green-chopped feed and hay grown with sewage sludge and inorganic fertilizer had similar livestock feeding qualities. Fertilizing wheat with sewage sludge delayed maturity.
    • 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.
    • Seeding Rate, Nitrogen Rate, and Planting Date of One-Irrigation Barley at Marana, 1987

      Ottman, Mike; Ramage, Tom; Thacker, Gary; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      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, one-irrigation barleys were grown at 4 seeding rates (20, 40, 60, and 80 lbs seed /A), 4 nitrogen rates (0, 50, 100, and 150 lbs/A), and 3 planting dates (Nov. 17, Dec. 15, and Jan. 22). Seeding rates 01 40 to 60 lbs seed/A resulted in the highest yields at the Dec. 15 planting date, comparing all planting dates combined. However, in individual analyses of the Nov. 17 and Jan. 22 planting dates, no significant differences in yield due to seeding rate were detected. Grain yield increased linearly with nitrogen rate at the Nov. 17 planting date, but was not influenced by nitrogen rate at the other planting dates. Yields were similar for the Nov. 17 and Dec. 15 planting dates, but decreased considerably in the Jan. 22 planting date due partially to lower head number. Grain yields of 2-22-9 were consistently higher than Seco this year.
    • Durum Wheat Variety Trials in Cochise, Graham and Greenlee Counties, 1987

      Clark, Lee; Schwennesen, Eric; Cluff, Ronald, E.; DeRosa, Edith; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Aldura, Westbred Turbo and Westbred 881 were grown in four sites in three counties (Graham, Greenlee and Cochise) in southeastern Arizona to determine which would produce the largest income per acre. At an assumed 75 cent premium for Westbred 881 over a base of $5.25 per hundredweight, Aldura and Westbred Turbo generally out produced Westbred 881. Relative yields of the three varieties are shown for all locations.
    • Corn Variety Trial in Bonita, Graham County, 1986

      Clark, Lee; Cluff, Ronald, E.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Fourteen corn hybrids were tested, only one of which had previously been evaluated in University tests. Yields, stands, moisture in the grain at harvest, net value of the crop (after subtracting drying costs) and other agronomic data were determined. The top -yielding hybrid, Pioneer 3183, produced 11,942 pounds per acre but produced about $2 per acre less than the highest valued variety, DeKalb 656, which produced $460.54 per acre.