• 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.
    • Winter Cereal Forage Variety Evaluation at Maricopa, 2016

      Ottman, Michael J; Sheedy, Michael D; Ward, Richard W (College of Agriculture, University of Arizona (Tucson, AZ), 2016-11)
      Winter cereals such as barley, oats, triticale, and wheat are commonly grown as forage for the dairy industry. The purpose of this study is to generate information on yield potential of various winter cereal forage varieties. A trial testing the yield potential of eleven winter cereal forage entries including barley, oat, triticale, and wheat varieties was established at the Maricopa Ag Center on October 16, 2015. Forage yields were obtained at cuttings on December 10, February 29, and April 18. The highest yielding entry at the first cutting was Stockford barley. At the second and third cuttings, the highest yielding entry was Summit 515 wheat. Summit 515 wheat was also the highest yielding entry averaged over all cuttings. As a group, the wheat entries were higher yielding that the other winter cereals except at the first cutting where the barleys were higher yielding.
    • 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.
    • Late Season N Application Method Effect on Grain Protein, 2016

      Ottman, Michael J; Sheedy, Michael D; Ward, Richard W (College of Agriculture, University of Arizona (Tucson, AZ), 2016-11)
      Nitrogen fertilizer is normally applied later in the season around flowering time to boost grain protein content. The purpose of this study is to determine if the grain protein boost provided by late N application is affected by method of application. A trial testing late season N application methods was conducted at the Maricopa Ag Center in the 2016 growing season. The crop was grown 211 lb N/acre in split applications until flowering when 35 lb N/acre was applied as UAN32 in the irrigation water (fertigation), as low biuret urea in a foliar application, or as urea granules compared to no N application at all at flowering. In this study, we were not able to detect a difference in grain protein or any other variable measured due to the late N application method. We did measure a 0.4% increase in grain protein regardless of late season N application method compared to the control with no late N applied.
    • Clipping small grains to increase subsequent grain yield

      Ottman, Michael J; Sheedy, Michael D; Ward, Richard W (College of Agriculture, University of Arizona (Tucson, AZ), 2016-11)
      Wheat is commonly grown as a dual purpose crop especially in the Southern Great Plains where the forage is grazed then allowed to mature into a grain crop. In Arizona, clipping a crop planted in October may increase tillering and grain yield. A trial was conducted at the Maricopa Ag Center where various small grain varieties were planted on October 12, 2015, cut for forage on January 10, 2016, and allowed to go to grain and compared with the same varieties planted on December 3, 2016 and not cut for forage. No differences in grain yield due to planting date and clipping were detected. However, the October 12 planting with clipping had larger kernels, greater grain protein, and higher stem density. The income from the sale of the forage was $99/acre based a yield of 2639 lb/acre and a forage value of $75/ton. The added cost per acre to produce this forage included $29 for water (6.27 inches of water at $55/acre-ft) plus $34 for fertilizer (50 lb N/acre of urea at $433/ton). Therefore, even though grain yield was not increased by planting early and clipping, a net increase in revenue of $36/acre was realized from the sale of the forage.
    • 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.
    • 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
    • Growing Grain Sorghum in Arizona

      Ottman, Michael J; Univ Arizona, Coll Agr & Life Sci (College of Agriculture, University of Arizona (Tucson, AZ), 2016-10)
      Production practices for grain sorghum are discussed including hybrid selection, planting date, seeding rate, row configuration, irrigation, fertilization, pest control, and harvesting. Grain sorghum (milo) is a warm season, annual grain crop. It is more resistant to salt, drought, and heat stress than most other crops. Nevertheless, highest yields are obtained when stresses are minimized. Revised 10/2016. Originally published 06/2009.
    • Laboratories Conducting Soil, Plant, Feed, or Water Testing

      Schalau, Jeff W.; Univ Arizona, Coll Agr & Life Sci (College of Agriculture, University of Arizona (Tucson, AZ), 2016-09)
      This publication lists laboratories that provide soil, plant, feed, and water testing within the state of Arizona. Revised September 2016.
    • Better Coverage of Arizona's Weather and Climate: Gridded Datasets of Daily Surface Meteorological Variables

      Weiss, Jeremy; Crimmins, Michael; Univ Arizona, Coll Agr & Life Sci (College of Agriculture, University of Arizona (Tucson, AZ), 2016-08)
      Many areas that use agricultural and environmental science for management and planning – ecosystem conservation, crop and livestock systems, water resources, forestry and wildland fire management, urban horticulture – often need historical records of daily weather for activities that range from modeling forage production to determining the frequency of freezing temperatures or heavy rainfall. In the past, such applications primarily have used station-based observations of meteorological variables like temperature and precipitation. However, weather stations are sparsely and irregularly located throughout Arizona, and due to the highly variable terrain across the state (Figure 1), information recorded at these sites may not represent meteorological conditions at distant, non-instrumented locations or over broad areas. This issue, along with others related to quality, length, and completeness of station records, can hinder the use of weather and climate data for agricultural and natural resources applications. In response to an increasing demand for spatially and temporally complete meteorological data as well as the potential constraints of station-based records, the number of gridded daily surface weather datasets is expanding. This bulletin reviews a current suite of these datasets, particularly those that integrate both atmospheric and topographic information in order to better model temperature and precipitation on relatively fine spatial scales, and is intended for readers with knowledge of weather, climate, and geospatial data. In addition to addressing how these datasets are developed and what their spatial domain and resolution, record length, and variables are, this bulletin also summarizes where and how to access these datasets, as well as the general suitability of these datasets for different uses.
    • Overseeding Winter Grasses into Bermudagrass Turf

      Kopec, David; Umeda, Kai (College of Agriculture, University of Arizona (Tucson, AZ), 2015-10)
      Describes the proper timing of overseeding, selecting winter grasses, and procedures to prepare for overseeding with the amount of seed to use followed by irrigating, fertilizing, and mowing.
    • Wheat and barley varieties for Arizona, 2015

      Ottman, Michael J (College of Agriculture, University of Arizona (Tucson, AZ), 2015-10)
      Grain yield, test weight, and other characteristics of barley, durum, and wheat varieties are provided in this publication
    • Nondormant Alfalfa Varieties for Arizona 2015

      Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2015-09)
      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.
    • Control of Brown Wood Rot in Lemons with Low Pressure Injection 2013-14

      Wright, Glenn C. (College of Agriculture, University of Arizona (Tucson, AZ), 2015-09)
      We injected AGRA PHOS (Potassium Phosphite) 0-2.4-2, Propiconizole – 0.05%, Zn, Mn and Fe 0.105, 0.112, and 0.10% respectively, Zn, Mn and Fe 0.210, 0.220, and 0.200% respectively and Propiconizole – 0.05% + Zn, Mn and Fe 0.105, 0.112, and 0.10% respectively using a low pressure injection system for the control of Antrodia sinuosa in lemon trees. No treatment led to a significant reduction in fungal growth.
    • Mowing Turfgrasses in the Desert

      Kopec, David; Umeda, Kai (College of Agriculture, University of Arizona (Tucson, AZ), 2015-09)
      Describes how to select the appropriate lawn mower to properly mow the species of grass at the correct height for high, medium, or low maintenance levels.
    • Biology and management of Fusarium wilt of lettuce

      Matheron, Michael E. (College of Agriculture, University of Arizona (Tucson, AZ), 2015-08)
      This publication provides information on the development and management of Fusarium wilt of lettuce. Topics covered include the characteristics of the plant pathogen, disease development, and disease management considerations.
    • Physiology of Cotton Defoliation

      Ayala, Felix; Silvertooth, Jeffrey C. (College of Agriculture, University of Arizona (Tucson, AZ), 2015-06)
      This bulletin deals with the physiology of cotton defoliation and attempts to describe what conditions must exist inside the plant in order for defoliation to occur. It is important to understand the basic physiological processes involved in order for best crop management practices to accomplish a successful defoliation. The objectives of defoliating a cotton crop can be simply stated as: 1) to remove leaves to facilitate mechanical picking, 2) to maintain the quality of the lint, and 3) to complete defoliation with a single application of chemicals.
    • Soil Management and Soil Testing for Irrigated Cotton Production

      Silvertooth, Jeffrey C. (College of Agriculture, University of Arizona (Tucson, AZ), 2015-06)
      In this article we will discuss various aspects of soil evaluation including physical examination, soil sampling and analysis, and soil test interpretation. We will also discuss how these approaches to soil evaluation can be incorporated into both short- and long-term management plans.
    • Determining the Mainstem Node Number for Cotton

      Silvertooth, Jeffrey C.; Brown, Paul W. (College of Agriculture, University of Arizona (Tucson, AZ), 2015-06)
      To systematically monitor a young crop effectively, it is important to understand the fundamentals about counting and identifying nodes on the plant. A mainstem node is simply the point on the plant stalk where a joint with a side branch (either vegetative or fruiting branch) is formed. The basic point of reference for counting nodes on a cotton plant are the cotyledonary nodes. The cotylendonary leaves are the first two leaves to appear as the plant emerges through the soil after planting, and are actually the former halves of the seed itself. Therefore, the cotyledons form the first nodes on the mainstem of the plant and they are the only nodes which are directly opposite one another, or parallel. When counting mainstem nodes we use the cotyledon nodes as 0, then counting subsequent nodes up the mainstem toward the terminal of the plant.
    • Early Cotton Development

      Silvertooth, Jeffrey C. (College of Agriculture, University of Arizona (Tucson, AZ), 2015-06)
      After stand establishment, the next critical stage in the development of a cotton crop is the initiation of the first squares, or floral buds, which could develop into the plants’ first boll. This is an important step for a cotton crop and one which is usually followed closely by the attentive farmer.