rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Biological control of Pythium damping-off in Amaranthus species
  name:
    name part: Sealy, Ramsey Lee
    name part: 1948-
    role:
      role term: creator
  name:
    name part: Kenerley, Charles M.
    role:
      role term: degree supervisor.
  name:
    name part: McWilliams, Edward L.
    role:
      role term: degree supervisor.
  name:
    name part: Cobb, B. Gregory
    role:
      role term: degree committee member.
  name:
    name part: Zuberer, David A.
    role:
      role term: degree committee member.
  name:
    name part: Texas A & M University
    role:
      role term: degree granting institution.
  type of resource: text
  genre: bibliography
  genre: Academic theses
  origin info:
    place:
      place term: xx
    date issued: 1988
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: xi, 124 leaves : illustrations ; 29 cm
  abstract: Several approaches to the biological control of damping-off in seedlings of Amaranthus L. seedlings by Pythium myriotylum Drechsler were investigated. One hundred twenty-six accessions of Amaranthus were screened for resistance to damping-off by P. myriotylum. Accessions ranged in resistance from very susceptible (>100.0% weighted mortality) in a vegetable cultivar of A. tricolor L. to very resistant (1.8% weighted mortality) in A. tricolor 'Early Splendor'. It was suggested that accessions that exhibited weighted percent mortalities of less than 20% be selected for use in breeding programs to breed in resistance to damping-off by P. myriotylum. Levels of oxalate and amarantin in roots and shoots of six cultivars of Amaranthus with differential resistance to damping-off by Pythium myriotylum were determined. Concentrations of neither compound were well correlated with resistance ; R^2 < 0.2 in all cases. The optimal temperature ranges for germination of seeds and growth of seedlings of Amaranthus hvbridus L. 'Quelite', for radial growth of Pythium myriotylum, and for disease development of Pythium damping-off in seedlings of A. hvbridus 'Quelite' when challenged by P. mvriotylum were determined using a temperature-gradient plate. The optimal range for germination of seeds of A. hvbridus 'Quelite' was 27.4 to 29.4 C. The optimal range for radial growth of P. myriotylum was 30.6 to 32.2 C. There was a significant correlation between disease development and temperature (R^2=0.987). The effects of three levels of light intensity on the severity of damping-off caused by Pythium myriotylum in Amaranthus hvbridus 'Quilete' were tested. The per cent mortality observed under the three light regimen (full, two-thirds, and one-third available light) were 33%, 69%, and 81%, respectively. Several biocontrol agents known to be antagonistic to Pythium species were evaluated for control of damping-off in Amaranthus cruentus L. X caudatus L. by Pythium mvriotylum. The agents were us…
  note: Typescript (photocopy).
  note: Vita.
  note: "Major subject: Horticulture."
  note: Ph. D. Texas A & M University 1988
  note: Includes bibliographical references.
  subject:
    topic: Amaranths
    topic: Breeding
  subject:
    topic: Damping-off diseases
    topic: Biological control
  subject:
    topic: Pythium
  subject:
    topic: Fungal diseases of plants
  subject:
    topic: Major horticulture
  identifier: http://gateway.proquest.com/openurl
  identifier: http://proxy.library.tamu.edu/login
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    location:
      url: http://proxy.library.tamu.edu/login
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    location:
      url: http://gateway.proquest.com/openurl
  record info:
    record content source: TXA
    record creation date: 900607
    record change date: 20200904152431.0
    record identifier: in00000905151
    language of cataloging:
      language term: eng