• Can Yield of Late-planted Small Grains be Compensated by Water and Nitrogen Rates, 2016?

      Ottman, Michael J; Sheedy, Michael D; Ward, Richard W (College of Agriculture, University of Arizona (Tucson, AZ), 2016-11)
      Wheat and barley are often planted later than optimum due to the timing of the previous crop or to reduce the risk of frost damage. It may be possible to partially compensate for lower yield potential of late plantings by increasing water and nitrogen rates beyond what would have an effect at more optimal plantings. The objective of this study is to evaluate the effects of nitrogen and water rates on late planted wheat and barley. A trial testing water and nitrogen rates for small grains planted late and at the optimal time was established at the Maricopa Ag Center. The experimental design was a split-split plot with main plots as input levels of water and nitrogen (low, medium, and high), subplots as varieties (Tiburon durum and Chico barley), sub-subplots as planting dates (15 December 2015 and 1 February 2016, and 3 replications. In this study, higher levels on inputs of water and nitrogen did not increase yield at later planting dates as we hypothesized. In fact, the highest yields were obtained at medium inputs of water and nitrogen regardless of planting date. The yields of the later planting date were not depressed as we expected due to unusually mild temperatures later in the spring which favored a later planting date this season.
    • Effect of Amount of Irrigation Water Applied on Forage Sorghum Yield and Quality at Maricopa, AZ, 2015

      Ottman, Michael J; Diaz, Duarte E; Sheedy, Michael D; Ward, Richard W (College of Agriculture, University of Arizona (Tucson, AZ), 2017-02)
      Irrigation water is a major input into production of a forage crop. The purpose of this research is to compare the yield and quality of forage sorghum grown with differing amounts of irrigation water. A linear move sprinkler system was used to apply 11 water application amounts from 23.79 to 35.52 inches over the season. Forage yield peaked at a water application amount of around 32.60 inches according to a quadratic function of yield vs water applied. Increasing irrigation amount decreased forage quality by increasing fiber components. Profit was maximized at 30.20 to 32.60 inches of applied water, which is slightly less than that for maximum yield.
    • Evaluation of Palisade as a Plant Growth Regulator in Durum, 2016

      Ottman, Michael J; Sheedy, Michael D; Ward, Richard W (College of Agriculture, University of Arizona (Tucson, AZ), 2016-11)
      Lodging has historically been a problem in small grain production. Palisade is a relatively new plant growth regulator that has shown some promise in reducing lodging. The effect of Palisade on height and lodging of durum, and subsequent yield was tested in a study at the Maricopa Ag Center. Plant height was not affected by Palisade since the chemical was applied at boot, one stage past the recommended window where the plant was near maximum height. Lodging was reduced from 83 to 61% and 28 to 8% under the high and medium input growing conditions, respectively. Grain yield was increased from 4481 to 6152 lb/acre and 5600 to 7330 lb/acre under high and medium input growing conditions, respectively. Palisade is effective in reducing but not eliminating lodging, and can have a large impact on yield as in this study.
    • Forage Sorghum Hybrid Yield and Quality at Maricopa, AZ, 2015

      Ottman, Michael J; Diaz, Duarte E; Sheedy, Michael D; Ward, Richard W (College of Agriculture, University of Arizona (Tucson, AZ), 2017-02)
      Forage sorghum is commonly grown in Arizona for silage for dairy cattle and is valued for its lower nitrogen fertilizer and water requirements compared to corn. Five forage sorghum hybrids were evaluated in a study conducted at the Maricopa Agricultural Center in 2015. The hybrids tested did not differ in yield or overall feeding quality (TDN, total digestible nutrients) although some differences in heading, plant height, moisture content, and some specific quality parameters were detected.
    • Irrigation Interval Effect on Yield and Quality of Forage Sorghum at Maricopa, AZ, 2015

      Ottman, Michael J; Diaz, Duarte E; Sheedy, Michael D; Ward, Richard W (College of Agriculture, University of Arizona (Tucson, AZ), 2017-02)
      Sorghum has the advantage compared to corn in that it uses less water and fertilizer, but feeding quality of sorghum is usually less than corn. The purpose of this research is to compare the yield and quality of sorghum grown with differing frequency of irrigation water application. Forage sorghum was grown at the University of Arizona Maricopa Agricultural Center with irrigation intervals of 1, 2, and 3-weeks corresponding to 76, 44, and 37 inches of applied water. Forage yield at 72% moisture was 20.6, 18.8, and 16.5 tons/acre for the 1-, 2-, and 3-week irrigation intervals, respectively. Forage quality in terms of milk per ton of forage was not affected by irrigation interval, but some differences were measured in certain components of feed quality. Forage yield profit was maximized at the 2-week irrigation interval due since the increased water cost of the 1-week interval was not compensated by the yield increase at this irrigation frequency.
    • Nitrogen Fertilizer Rate Effect on Forage Sorghum Yield, Quality, and Tissue Nitrogen Concentrations at Maricopa, AZ, 2015

      Ottman, Michael J; Diaz, Duarte E; Sheedy, Michael D; Ward, Richard W (College of Agriculture, University of Arizona (Tucson, AZ), 2017-02)
      A nitrogen fertilizer study was conducted in order to determine the effect of N rates on forage sorghum yield and quality and to develop tissue testing guidelines for fertilizer application to forage sorghum. The study was conducted at the University of Arizona Maricopa Agricultural center on sandy clay loam soil irrigated using the flood method. Forage sorghum was fertilized with six N rates varying from 0 to 250 lb N/acre in 50 lb N/acre increments. The whole plant, lower stem, and most recently expanded leaf were sampled five times during the growing season and analyzed for N content in order to establish tissue N guidelines for fertilizer application. The plant part that was most sensitive to N fertilizer application and plant N status was lower stem. Leaf and plant N levels were not affected by fertilizer application. The stem nitrate and stem N tests were able to identify N deficient plants very early in the season, long before plant growth was affected by the N deficiency, unlike leaf and plant N. Forage yield at final harvest fitted to a quadratic function was maximized at the 250 lb N/acre N rate. However, the yield increase with any amount of fertilizer did not pay for the cost of the fertilizer and the most economical N rate for yield was no N fertilizer applied at all. In terms of milk per acre, the maximum was achieved at 150 lb N/acre, and the economic optimum in terms of milk was slightly less than this amount of fertilizer.
    • Nondormant alfalfa varieties for Arizona 2016

      Ottman, Michael J; Univ Arizona, Coll Agr & Life Sci (College of Agriculture, University of Arizona (Tucson, AZ), 2016-10)
      Alfalfa varieties differ in fall dormancy, defined as growth during the fall. Nondormant alfalfa varieties are usually planted in mild winter areas for their ability to grow in the late fall, winter, and early spring. Select alfalfa varieties that have resistance to potential pest problems. Alfalfa varieties are available that have salt tolerance or are Roundup Ready. Ratings are provided in this publication. Many of the varieties listed in this publication have been tested for yield and final stand by the University of Arizona in small plot trials. Revised 10/2016. Most recent version 09/2015
    • Planting Dates for Small Grains in Arizona

      Ottman, Michael J (College of Agriculture, University of Arizona (Tucson, AZ), 2015-05)
      Planting at the optimum time is probably the most important cultural practice in producing high small grain yields. Wheat and barley crops that are planted too early or too late have lower yield potential no matter how they are grown after planting. However, small grains are sometimes planted later than optimum when grown in rotation with cotton or vegetables due to harvest timing in these crops. Therefore, the entire farm enterprise should be considered when deciding on a planting date for small grains.
    • Row Spacing Effect on Forage Sorghum Yield and Quality at Maricopa, AZ, 2015

      Ottman, Michael J; Diaz, Duarte E; Sheedy, Michael D; Ward, Richard W; Univ Arizona, Coll Agr & Life Sci (College of Agriculture, University of Arizona (Tucson, AZ), 2017-02)
      Forage sorghum yields have been should to increase with narrow row spacing of 20 inches or less. The purpose of this research is to determine the effect of narrow row spacing on forage sorghum yield and quality in Arizona. Two row spacing (20 and 40 inch) and two forage sorghum hybrids (Great Scott and Silo 700D BMR) were evaluated in a study conducted at the University of Arizona Maricopa Agricultural Center in 2015. Row spacing had no effect on forage yield, moisture, plant height, or maturity even though light interception was greater for the closer row spacing. The only feed quality parameter affected by row spacing was lactic acid which increased with row spacing. Hybrid by row spacing interactions was detected for a few feed quality parameters. Decreasing forage sorghum row spacing from 40 to 20 inches does not appear to have an advantage based on the results of this study.
    • Wheat and barley varieties for Arizona, 2016

      Ottman, Michael J; Univ Arizona, Coll Agr & Life Sci (College of Agriculture, University of Arizona (Tucson, AZ), 2016-10)
      Grain yield, test weight, and other characteristics of barley, durum, and wheat varieties are provided in this publication.Revised 10/2016. Previous version 10/2015.
    • Wheat and barley varieties for Arizona, 2017

      Ottman, Michael J (College of Agriculture, University of Arizona (Tucson, AZ), 2017-10)
      Grain yield, test weight, and other characteristics of barley, durum, and wheat varieties are provided in this publication. Revised 2017, Previous version10/2016. Previous version 10/2015.