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:
    non sort: A
    title: study of sorghum diseases in Honduras, their importance under different cropping systems, and strategies for their control
  name:
    name part: Wall, George Clayton
    name part: 1946-
    role:
      role term: creator
  name:
    name part: Craig, Jeweus
    role:
      role term: degree committee member.
  name:
    name part: Frederiksen, Richard A.
    role:
      role term: degree supervisor.
  name:
    name part: Jeger, Michael J.
    role:
      role term: degree committee member.
  name:
    name part: Rosenow, Darrell T.
    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: 1986
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: xii, 108 leaves : illustrations ; 29 cm
  abstract: Twenty-one sorghum diseases were identified in different sorghum-growing regions of Honduras, of which eight were studied with regard to their effect on sorghum yield. Sorghum downy mildew, caused by Peronosclerospora sorghi, was studied by comparing three near-isogenic populations (resistant, intermediate, and susceptible), planted in a disease-free site and in the presence of the disease. A 52% incidence of downy mildew reduced yields by 46%. Paired comparisons of diseased and healthy plants showed that maize dwarf mosaic, an aphid-transmitted virus disease, caused a 52% yield reduction on traditional land race cultivars. The same technique was used to study the effect of Acremonium wilt, caused by Acremonium strictum, which caused a 36% yield reduction on a susceptible cultivar (BTX623), and a 33% yield loss on land race cultivars. A holistic, multivariate study, carried out in subsistence farmers' fields, produced a multiple regression model for estimating sorghum yields based on plant height, panicle length, and disease severity data. Using this model, a 14.6% yield reduction was estimated to be caused by gray leaf spot (Cercospora sorghi), based on severity levels observed in farmers' fields. Rust (Puccinia purpurea) was estimated to cause a 3.5% yield reduction, and oval leaf spot (Ramulispora sorghicola) reduced yields by 5.5%. In controlled experiments using fungicide-protected and unprotected plots, zonate leaf spot (Gloeocercospora sorghi) caused a 15% yield reduction. Gray leaf spot, in a similar trial, reduced yields by 13.5% on the most popular improved cultivar (Tortillero). When cropping systems were compared, sorghum-maize was found to have a lower oval leaf spot severity than sorghum alone, but the maize dwarf mosaic incidence was higher. Early planting resulted in higher disease severities than late planting of photoperiod-sensitive land race cultivars. Improved cultivars had fewer diseases, but higher severities, than land race cultivars when bot…
  note: "Major subject: Plant Pathology."
  note: Typescript (photocopy).
  note: Vita.
  note: Ph. D. Texas A & M University 1986
  note: Includes bibliographical references (leaves 103-107).
  subject:
    geographic code: ncho---
  subject:
    topic: Crop yields
    geographic: Honduras
    topic: Mathematical models
  subject:
    topic: Sorghum
    topic: Diseases and pests
    geographic: Honduras
  subject:
    topic: Sorghum
    topic: Losses
    geographic: Honduras
  subject:
    topic: Major plant pathology
  subject:
    topic: Crop yields
    topic: Mathematical models
  subject:
    topic: Sorghum
    topic: Diseases and pests
  subject:
    topic: Sorghum
    topic: Losses
  subject:
    geographic: Honduras
  identifier: http://proxy.library.tamu.edu/login
  identifier: https://hdl.handle.net/1969.1/DISSERTATIONS-24934
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: https://hdl.handle.net/1969.1/DISSERTATIONS-24934
  record info:
    record content source: TXA
    record creation date: 880621
    record change date: 20220104090746.0
    record identifier: in00000016964
    language of cataloging:
      language term: eng