• 2012 Sorghum Silage Variety Trial at Maricopa

      Loper, Shawna; Ottman, Mike; Ottman, Michael J.; School of Plant Sciences / Maricopa Ag Center, University of Arizona (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2013-05)
      Nine varieties of silage sorghum and one pearl millet variety were tested at the Maricopa Agricultural Center in Maricopa, AZ. Information on silage sorghum yield and quality can be of use to the dairy industry and help growers choose the best varieties based on their needs. We found no significant differences among the varieties for ash, ADF, and NDF. We did find significant differences in yield with Silo 700 BMR having the highest yield with 31.62 tons/acre and GS125 having the lowest with 20.53 tons/acre. We also saw significant differences in crude protein with ExpGD having the highest (3.47%) and Silo 700 BMR (1.93%) being the lowest.
    • Cultivar and Nitrogen Effects on Yield and Grain Protein in Irrigated Durum Wheat, 2012

      Wang, Guangyao (Sam); Brunson, Kevin; Thorp, Kelly; Ottman, Mike; Ottman, Michael J.; School of Plant Sciences / Maricopa Ag Center, University of Arizona; Arid-Land Ag Research Center, USDA-ARS, Maricopa, AZ (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2013-05)
      The grain yield and nitrogen use efficiency of durum wheat vary in response to genotypic and nitrogen fertilization were studied in field during two growth seasons. The aim of this study was to evaluate the effects the N fertilizer rate on grain yield and quality under irrigated desert conditions in relation to N utilization. Six durum wheat cultivars (Duraking, Havasu, Kronos, Ocotillo, Orita, Topper) were grown in field trails under irrigated regimes at five N levels (0, 65, 110, 160, 240 lbs/acre) in 2010-2011 and six N levels (0, 65, 110, 160, 240, 360 kg ha-1) in 2011-2012 at Maricopa Ag Center. The results showed the varieties and N levels both significantly affected grain yield, grain protein concentration, and nitrogen use efficiency. A simple and rapid method to measure crop N status using SPAD meters was also developed. The results showed that using the differences in SPAD readings between the first and second fully expanded leaves is a useful way to improve effectiveness of SPAD meters in durum wheat N management.