• Nondormant Alfalfa Varieties for Arizona 2017

      Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 2017-09)
      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 fall. However, fall growth of nondormant alfalfa may be undesirable in areas subject to repeated frosts or freezes. Nondormant, very nondormant, and extremely nondormant alfalfa varieties (fall dormancy class 8, 9, and 10) are adapted to elevations below 4000 feet in Arizona. Other dormancy classes not included in this publication are moderately nondormant varieties (fall dormancy class 7) which may be grown from 3000 to 5000 feet, and semi-dormant and dormant varieties (fall dormancy 6 and below) which are adapted to colder winter areas above 4000 feet.
    • Biology and Management of Downy Mildew of Lettuce

      Matheron, Michael E. (College of Agriculture, University of Arizona (Tucson, AZ), 2015-09)
      This publication describes the factors affecting development of downy mildew of lettuce and provides disease management strategies.
    • 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.
    • 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.
    • Cultural Practices for Karnal Bunt Control

      Ottman, Michael J (College of Agriculture, University of Arizona (Tucson, AZ), 2015-05)
      Environmental conditions between awn emergence and the end of flowering is the overriding factor in disease development. 2 The University of Arizona Cooperative Extension Cultural practices may be partially effective in controlling Karnal bunt but cannot eliminate the disease completely. Karnal bunt is most likely to be found in areas where lodging or water ponding have occurred.
    • Pine Bark Beetles

      DeGomez, Tom; Young, Deborah (College of Agriculture, University of Arizona (Tucson, AZ), 2015-04)
      Pine bark beetles in Arizona are generally of the genus Ips or Dendroctonus. Fading foliage in the tree is often the first sign of a beetle attack. Prevention is best practiced since control is not possible once the beetles have successfully colonized the tree. Colonization is dependent upon trees being in a vulnerable condition caused by stress from various agents and site conditions.
    • Cotton (Texas) Root Rot

      Olsen, Mary (College of Agriculture, University of Arizona (Tucson, AZ), 2015-02)
      The most important disease of woody dicotyledonous plants in Arizona is Phymatotrichopsis root rot (Cotton or Texas root rot) caused by a unique and widely distributed soil-borne fungus, Phymatotrichopsis omnivora. The fungus is indigenous to the alkaline, low-organic matter soils of the southwestern United States and central and northern Mexico.
    • Control of Brown Wood Rot in Lemons with Low Pressure Injection 2012

      Wright, Glenn C.; Department of Plant Sciences, University of Arizona; Yuma Agriculture Center, Yuma, AZ (College of Agriculture, University of Arizona (Tucson, AZ), 2015-02)
      We injected AGRA PHOS (Potassium Phosphite) 0-2.4-2, Propaconizole – 0.05%, Propaconizole plus Azoxystrobin – 0.117 and 0.135% respectively, Zn, Mn and Fe 0.105, 0.112, and 0.10% respectively, and Azoxystrobin – 0.137% using a low pressure injection system for the control of Antrodia sinuosa in lemon trees. The Propaconizole + Azoxystrobin treatment, the Azoxystrobin treatment, and the Zn + Mn + Fe treatment led to significantly less fungal lesion growth when applied prior to the introduction of the fungus, as compared to their application after fungal introduction.
    • Susceptibility of Mesquite Species to Powdery Mildew in Arizona

      Nischwitz, Claudia; Olsen, Mary W.; Department of Biology, Utah State University, Logan, Utah; University of Arizona, College of Agriculture and Life Sciences (College of Agriculture, University of Arizona (Tucson, AZ), 2014-12)
      Mesquite (Prosopis sp.) is a popular tree in landscapes in Arizona because of its drought tolerance and attractive growth habit. Powdery mildew has been observed from late summer until early spring on mesquite leaves. It has been identified as Pleochaeta polychaeta based on morphological descriptions and comparison to herbarium specimens. Surveys were conducted in fall 2008 through winter 2009 at two locations in southern Arizona to determine the susceptibility of different mesquite species to powdery mildew. Twelve mesquite trees representing two species were sampled at Texas Canyon near Willcox, AZ, and 177 trees representing eight species were sampled at the University of Arizona campus in Tucson, AZ. The North American mesquite species P. glandulosa var. glandulosa and P. velutina were infected with powdery mildew at the University of Arizona campus and P. velutina at the Texas Canyon site. No powdery mildew was observed on P. alba, P. cinerea, P. nigra, P. chilensis, P. pubescens and P. chilensis x flexuosa. The powdery mildew affects the aesthetic value of severely infected trees but seems to have little effect on long term tree health.
    • Seiridium Canker of Cypress Trees in Arizona

      Schalau, Jeff (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2012-01)
    • Salinity Management and Soil Amendments for Southwestern Pecan Orchards

      Walworth, J. L. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011-10)
    • Beet Curly Top Disease (Curtoviruses) in Spinach and Table Beets in Arizona

      Nischwitz, Claudia; Olsen, Mary (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011-10)
    • Leaf Sampling Guide with Interpretation and Evaluation for Arizona Pecan Orchards

      Walworth, James L.; Pond, Andrew P.; Kilby, Michael W. (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011-10)
    • Diseases of Citrus in Arizona

      Olsen, Mary; Matheron, Mike; McClure, Mike; Xiong, Zhongguo (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011-08)
    • Root-knot nematode

      Olsen, Mary W.; Plant Pathology (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011-01)
      Nematodes are microscopic round worms found in many habitats. They are the most abundant multicellular organisms on earth. Most are beneficial memebers of their ecosystems, but a few are economic parasites of plants and animals. There are several plant parasitic nematodes that cause problems on landscape and garden plants in Arizona and the most widespread and economically important are the root-knot nematodes. This article discusses the hosts and environmental conditions, symptoms and disease of root-knot nematode, and the prevention / control method to it.
    • Damping Off

      Olsen, Mary W.; Young, Deborah; Plant Pathology (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011-01)
      Damping off is caused by several different fungi under different environmental conditions. The fungi include Pythium, Rhizoctonia solani, and Thielaviopsis basicola. This article discusses the symptoms, environmental conditions, diseases, prevention and control methods for the damping-off caused by fungi.
    • Dwarf Mistletoes

      Olsen, Mary W.; Young, Deborah; Plant Pathology (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011-01)
      Dwarf mistletoes are parasitic flowering plants that grow within host plants for about two years before producing characteristic yellow to orange or green to brown leafless aerial shoots on the outside of infected host tissue. They occur only on conifers in the pine family in Arizona and are usually host specific. This article gives information about the disease cycle, the symptoms and prevention and control methods for dwarf mistletoes.
    • Sooty Canker

      Olsen, Mary W.; Young, Deborah; Plant Pathology (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011-01)
      Sooty canker causes cankers and dieback in tree branches. This article briefly explains the host, symptoms, environmental conditions, disease and preventing / controlling method for sooty canker.
    • Powdery Mildew

      Olsen, Mary W.; Plant Pathology (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011-01)
      Powdery mildew, a plant disease, appears as white, powdery spots on the leaf surface of several different kinds of plants. They are specific to their hosts and one type will infect only certain plants, usually those in the same or closely related plant families. This publication discusses the symptoms, environmental conditions, disease of powdery mildew and the methods used to prevent / control this plant disease.
    • Fire Blight

      Olsen, Mary W.; Young, Deborah; Plant Pathology (College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011-01)
      Fireblight is a bacterial disease that affects only plants in the rose family, particularly apple, pear and pyracantha. This article briefly discusses the symptoms and environmental conditions for this disease and the way to control it.