• 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 and Barley Variety Test at the Bruce Church Range, Poston, 1987

      Winans, Sherwood; Ottman, Mike; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      A wheat and barley test on the Bruce Church Ranch, Poston, Arizona, La Paz County, harvested June 8 & 9, 1987, gave crop and variety performance differences under grower management conditions. The top yielding barley variety was Fiesta, 6990 lbs /ac. The leading durum varieties were Turbo, Gem and Aldura. Durum wheat Westbred 881 was highest in protein (13.7 %). In red wheat varieties, yields ranged from 4660 to 5750 lbs/ac. The top three varieties were Baker, Probred and Yecora Rojo. Baker was highest in protein (14.6 %), followed by Yecora Rojo (14.2%). Continued testing over several years is necessary to assess variety performance under grower management conditions.
    • 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.
    • 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.
    • 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.
    • Wheat, Barley and Oats for Forage and Grain Production at the Yuma Valley Agricultural Center, 1986-87

      Tickes, Barry; Ottman, Mike; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      The potential of various types of small grains for winter forage production was investigated in this study. Two varieties of red wheat, durum wheat, barley, and oats were harvested at various stages. Harlan if barley produced the most forage at the early cutting while Mesa oats yielded the most forage at the later cutting. Gustoe barley produced the highest grain yields.
    • 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.
    • 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.
    • 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.
    • 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.
    • Grain Sorghum Variety Trial in Greenlee County, 1986

      Clark, Lee; DeRose, Edith; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Eleven full season hybrid grain sorghums, representing seven commercial sources, were grown on a silty clay soil south of Duncan. The test plots were managed the same as the rest of the field planted to DeKalb 69. Grain yields ranging from 6911 to 4546 pounds per acre were obtained, with DeKalb 69 the top yielder.
    • 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.
    • 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.
    • 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.
    • Barley Grain Grown with Dried Sewage Sludge

      Day, Arden; Thompson, Rex; Swingle, Spencer; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      A four-year experiment, conducted at the Mesa Agricultural Center, studied the use of dried sewage sludge from the City of Phoenix as a source of plant nutrients in the commercial production of barley grain. The objective was to compare the effects of sewage sludge and commercial fertilizer on barley growth, grain yield, and quality. Three fertilizer treatments were used: (1) suggested rates of nitrogen (N), phosphorus (P), and potassium (K) in Arizona; (2) dried sewage sludge to supply plant-available N in amounts equal to the suggested rate; and (3) N, P, and K from inorganic fertilizers, in amounts equal to those in sewage sludge. Characteristics of barley growth, grain yield, and quality were similar for the three fertilizer treatments. Barley can use the fertilizer nutrients in dried sewage sludge to produce grain as effectively as it can utilize the fertilizer nutrients in inorganic fertilizer.
    • 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.
    • 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.
    • Seedling Alfalfa Root Research

      Reffruschinni, Katie; Robinson, David; Dobrenz, Albert; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      There has been limited research on the rooting patterns of alfalfa. This information would be important in developing new germplasm sources that are more water efficient, salt tolerant and drought tolerant. Ten alfalfa varieties were evaluated for possible genetic control of rooting traits. Seedlings were grown hydroponically in a growth chamber. The cultivars evaluated showed a significant statistical difference for width of lateral root system and number of lateral roots. The variation in seedling rooting patterns is sufficient to warrant a selection program for improved lateral rooting patterns.
    • Alfalfa Variety Trial in Greenlee County, 1986

      Clark, Lee; DeRose, Edith; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Ten alfalfa varieties ranging from very non -dormant to moderately dormant were tested. No statistically significant differences were seen. The highest yielding variety yielded more than seven tons per acre, considerably better than the county average of 5.5 tons per acre.