• Determination of Optimal Planting Configuration of Low Input and Organic Barley and Wheat Production in Arizona, 2012

      Ottman, M. J.; Andrade-Sanchez, P.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2012-06)
      Markets for organic barley and wheat are expanding. A major problem growing organic barley and wheat is controlling the weeds. Organic barley and wheat were grown in conventional 6-inch drill spacing but also in 30 inch spacing so weeds could be cultivated in a study at the Larry Hart Farm near Maricopa. The weed pressure was moderate and the weed biomass was about 1 to 5% of the crop biomass near maturity. The primary weed was Palmer amaranth. Grain yields of the wheat (durum) were similar regardless of row spacing, but the barley grain yields were 3921 lbs/acre in the 6 inch spacing and 2530 lbs/acre in the 30 inch spacing.
    • Invinsa Application to Reduce Water Stress Effects on Corn Growth and Yield at Maricopa, AZ, 2012

      Ottman, M. J.; Kimball, B. A.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2012-06)
      Invinsa blocks ethylene perception by plants and can reduce the negative effects of water stress on crop growth. The objective of this study is to measure the effect on corn growth and yield of Invinsa application at incipient water stress. A study was conducted at the University of Arizona Maricopa Agricultural Center where Invinsa was applied on 15 May in blocks with adequate or deficit irrigation. The deficit irrigation block received no irrigation water for 7 days past incipient stress beginning on 15 May, but otherwise received adequate water during the other parts of the season. Invinsa had little or no effect on crop growth measured at five different dates during the growing season. Invinsa had no effect on grain yield, grain moisture content, harvest index, ear number, kernels per ear, kernel weight, and silking date. We were not able to measure an effect of Invinsa on photosynthetic rate, conductance to water, intercellular CO2 concentration, vapor pressure deficit, or leaf temperature. However, Invinsa increased daily water use at various time periods, particularly in the adequate irrigation regime. The lack of a response this year to Invinsa, other than water use, is similar to the results from last year where no consistent response was measured. Invinsa has increased corn yield in other regions, and heat and/or water stress at the Maricopa may mask the effects of Invinsa or render it ineffective.
    • Silage Corn Variety Trial in Central Arizona

      Loper, Shawna; Subramani, Jay; Ottman, Michael J.; University of Arizona of Arizona Cooperative Extension, Pinal County; Maricopa Ag Center, University of Arizona (College of Agriculture, University of Arizona (Tucson, AZ), 2012-06)
      Ten varieties of silage corn were tested at the Maricopa Agricultural Center in Central Arizona. Information on silage corn yield and quality can help the dairy industry and silage growers choose varieties that best fit their needs. There were no significant differences between any of the varieties tested with respect to ‘yield per acre’, ‘crude protein’, NDF or ‘ash content'. We were able to find significant differences with ADF.
    • Small Grains Variety Evaluation at Arizona City, Coolidge, Maricopa and Yuma, 2012

      Ottman, M. J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2012-06)
      Small grain varieties are evaluated each year by University of Arizona personnel. The purpose of these tests is to characterize varieties in terms of yield and other attributes. Variety performance varies greatly from year to year and several site-years are necessary to adequately characterize the yield potential of a variety. A summary of small grain variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1265.pdf.