• Alfalfa Varieties and Experimentals: Yield Evaluation Progress Report, Maricopa Agricultural Center, 1987

      Thompson, Rex; Sheedy, Michael; 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)
    • 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)
    • PEG-Induced Stress on Alfalfa Seedlings

      Ellsworth, Todd; Robinson, David; Dobrenz, Albert; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Summary of Commercial Hybrid Grain Sorghum Yield Tests at Marana, 1983-85

      Ottman, Mike; Voigt, Robert; Schmalzel, Carl; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Standardization of the Wheat Stem Tissue NO₃-N Procedure

      Knowles, Tim; Doerge, Thomas; Ottman, Mike; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Current University of Arizona recommendations require periodic stein NO₃-N tests to determine nitrogen (N) fertility status of wheat crops. Lack of data on the importance of sample handling techniques, plant part selection, grinding criteria and extraction conditions have resulted in a reluctance by some growers and laboratory operators to utilize this test procedure. A laboratory study was carried out to examine factors important in wheat stem tissue analysis for NO₃-N. Sample handling, fineness of tissue grinding, and different extraction ratios were examined to determine their effects on NO₃-N recovery. Detailed partitioning of wheat plants at the 3-4 leaf, joint and boot growth stages was conducted to document which plant part is the best indicator of the N status of wheat. Optimal recovery of tissue NO₃-N existed for stem tissue separated immediately in the field and dried within 8 hours; stem tissue ground to 30 mesh or less and extracted for at least 30 minutes; and when using a sample size of 0.1000 g, in conjunction with 25 ml of extractant (i.e. 1:250 plant tissue to extractant ratio). Partitioning data confirmed current University of Arizona wheat tissue sampling guidelines which suggest sampling of the basal portion of the stem tissue.
    • 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)
    • 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)
    • Effects of N and P Applications on Wheat Stem Nitrate and Phosphate Levels, and Grain Production in Graham County

      Knowles, Tim; Doerge, Thomas; Ottman, Mike; Clark, Lee; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Obtaining optimal yields of spring wheat in Arizona normally requires applications of fertilizer nitrogen (N), and occasionally phosphorus (P). The University of Arizona currently recommends preplant soil tests for NO₃-N and P, plus periodic stem tissue NO₃-N analyses to predict the N and P needs of wheat. Preplant application of P within the root zone of growing plants is suggested due to the immobility of P in soils. Split applications of N broadcast to dry soil preceding irrigations are generally recommended. Collecting additional data to calibrate and refine current guidelines for interpreting soil and plant test values is an ongoing need in Arizona. An experiment was conducted at the Safford Agricultural Center during the 1986-87 crop year to evaluate the response of "Aldura" durum wheat to banded and broadcast N and P, and split applications of N on a clay loam soil testing low in NO₃-N and available P. Maximum grain yields of over 4,500 lbs./A were obtained by banding of 40 lbs. P₂O₅ /A and 32 lbs. N/A as 16-20-0 at planting and broadcasting 118 lbs. urea-N/A prior to seeding. Stem tissue NO₃-N analyses revealed that N deficient conditions prevailed throughout the growing season in all fertilizer treatments. Treatments in which the preassigned rate of N was split into three applications produced the lowest yields due to serious N deficiency early in the season. The stem NO₃-N tissue test proved accurate in predicting N status and a stem. PO₄-P tissue test seemed reliable in monitoring P nutrition of durum wheat.
    • 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.
    • 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.
    • Corn Variety Trial in Bonita, Graham County, 1986

      Clark, Lee; Cluff, Ronald; 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.
    • Double-Crop Grain Sorghum Variety Trial, Graham County, 1986

      Clark, Lee; Cluff, Ronald; 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.
    • Stomatal Response to Water Stress in Two Pearl Millet Genotypes

      Osman, Mohamoud; Dobrenz, Albert; Tewolde, Haile; Voigt, Robert; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      A study was conducted in the field to test whether stomatal sensitivity to water stress can be used as a selection criterion for drought tolerance in two pearl millet genotypes. In both cultivars, stomatal aperture was significantly reduced by the water stress. However, the proportion of reduction per 20 mm decrease in applied water was much higher for the hybrid than for the female parent. This is clearly an indication of a higher stomatal sensitivity in the hybrid, which probably explains the superior performance under water stress that was previously observed in this genotype.
    • 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.
    • Predicting the Nitrogen Requirements of Irrigated Durum Wheat in Graham County Using Soil and Nitrate Analysis

      Doerge, Thomas; Knowles, Tim; Ottman, Mike; Clark, Lee; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      The high yielding spring wheats grown in Arizona usually require applications of fertilizer nitrogen (N) to achieve optimum grain yields and acceptable quality. The University of Arizona's currently recommended procedure (preplant soil plus periodic stem tissue analysis for NO₃-N to predict the N needs of wheat) is not widely used by Graham County growers for various reasons. A nitrogen fertility trial was conducted at the Safford Agricultural Center during the 1986-87 crop year to: 1) examine the relationships between basal stem nitrate-N levels, grain yields of durum wheat, and N fertilizer rates; and 2) to test the accuracy of the recommended procedure for predicting the N needs of durum wheat. Five rates of N from O to 419 lbs N /acre were applied in three split applications. One additional N treatment was made as indicated by the current University of Arizona procedure. Maximum grain yields of 5500 to 6200 lbs /a and protein levels in excess of 14.5% were attained with the application of at least 186 lbs NIA. An untimely early season irrigation induced a temporary N deficiency condition for all plots, which may have kept grain yields below the maximum yield possibility for this site. In spite of this, the amount of N predicted by the University of Arizona procedure (197 lbsN/acre) did attain an adjusted economic return which was not significantly different from the maximum numerical yield that was achieved for any of the other N treatments.
    • 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.
    • 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.