• 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.
    • 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.
    • PEG-Induced Stress on Alfalfa Seedlings

      Ellsworth, Todd; Robinson, David; Dobrenz, Albert; 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)
    • 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)
    • 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.
    • 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.
    • 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)
    • Cost of Producing Wheat in Arizona: 1987 State Summary

      Wade, James; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Effects of Sewage Sludge on the Yield and Quality of Wheat Grain and Straw

      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 grain and straw from wheat. Wheat grown with the recommended amount of plant -available nitrogen from sewage sludge produced the same grain yield as wheat grown with the same amount of nitrogen from inorganic fertilizer. Wheat grain and straw grown with sewage sludge and inorganic fertilizer had similar livestock feeding qualities. Fertilizing wheat with sewage sludge delayed maturity.
    • Small Grain Comparisons at the Maricopa Agricultural Center in 1987

      Thompson, Rex; Sheedy, Michael; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • 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.
    • Winter Wheat Variety Trial in Cochise County, 1987

      Clark, Lee; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Sixteen winter wheat varieties (including three hybrids) were evaluated in a randomized, complete block experiment, with four replications. Stephens, the standard variety grown in the area, was outyielded by four of the winter wheat cultivars, including two of the hybrids. The highest yielding cultivar was a hybrid, Bounty 100, which yielded 5853 pounds per acre (23% higher than Stephens).
    • Durum Wheat Variety and Planting Rate Trial at Marana in 1987

      Thacker, Gary; Ottman, Mike; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Five varieties of durum wheat were evaluated at two different seeding rates, in cooperation with Pacheco Farm Management in Marana. Significant differences between varieties were observed in grain yield, plant height, lodging, bushel weight and protein level. No significant differences in yellow berry were observed between the varieties. The planting rates did not cause significant differences in grain yield nor in any of the other characteristics that were measured. There were no significant variety x planting rate interactions.
    • 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.
    • Response of Alfalfa to Phosphorus Fertilizer Sources

      Stroehlein, Jack; Clark, Lee; DeRosa, Edith; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      A field study was carried out to determine the effects of different fertilizers on yield and quality of alfalfa. Two harvests over a period of four cuttings did not reveal any differences due to treatment. While alfalfa often responds to phosphorus (P) fertilizer application, conditions in this study provided adequate P as well as nitrogen (N) and potassium (K).
    • Salt Tolerance During Seedling Establishment in Alfalfa

      McKimmie, Tim; Dobrenz, Albert; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Deposition of salts from irrigation water is an increasing concern for Arizona farmers and agronomists. Selection for salt tolerance during the seedling stage has been undertaken over the past three years. Yield tests were conducted in greenhouses and a significant increase in dry matter production was shown in the selected material.
    • 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.
    • One-Irrigation Barley Observations in Graham and Cochise Counties, 1987

      Clark, Lee; Young, Deborah; Schwennesen, Eric; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      A series of experimental plots was planted because ranchers, conservationists, farmers and homeowners in southeastern Arizona were interested in knowing more about one -irrigation barleys. The results of these observations are contained in this paper.
    • Double-Crop Grain Sorghum Variety Trial, Graham County, 1986

      Clark, Lee; Cluff, Ronald, E.; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Nine medium to medium -late maturing grain sorghum hybrids were compared for yield, percent moisture at harvest, bushel weight, plant height, percent bird damage and standability. The highest yielding entry in the trial was a new hybrid from Northrup King (NK 2656). Its yield of 6185 pounds per acre was 11% higher than the most, commonly grown hybrid in the area.