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Filtering by: Creator Woodson, C. B. Remove constraint Creator: Woodson, C. B. Academic Affiliation Botany and Plant Pathology Remove constraint Academic Affiliation: Botany and Plant Pathology Degree Name Doctor of Philosophy (Ph.D.) Remove constraint Degree Name: Doctor of Philosophy (Ph.D.)

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  • Ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae)

    Creator:
    Campanella, Donald M.
    Abstract:
    A study consisting of three parts was undertaken to investigate how variation in species interactions, population genetic structure, epidemiological parameters, and plant breeding system may influence the ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae). Interactions between natural enemy species may modify their net effect on...
    Resource Type:
    Dissertation
    Full Text:
    : _______________________________ ______________________________ Peter B. McEvoy Christopher C. Mundt A study

  • Interrelationship of wheat cultivar mixtures, stripe rust and yield

    Creator:
    Akanda, Shamsul I.
    Resource Type:
    Dissertation
    Full Text:
    , Stripe Rust and Yield Abstract approved: Christopher C. Mundt Four club wheat (Triticum aestivum

  • Host and Pathogen Genetics in the Sharp Eyespot Disease of Wheat

    Creator:
    Liu, Jiang
    Abstract:
    Wheat sharp eyespot (SES), caused by the soil-borne fungus Rhizoctonia cerealis is a common stem disease of wheat globally. The disease caused a severe and extensive epidemic throughout the Willamette Valley of Oregon in 2014 and has remained one of the most important wheat diseases in this region. However, litte...
    Resource Type:
    Dissertation
    Full Text:
    :_______________________________________________________________ Christopher C. Mundt Wheat sharp eyespot (SES), caused by the soil-borne fungus

  • Post-dispersal seed fates in a Western Oregon native prairie

    Creator:
    Clark, Deborah L.
    Abstract:
    Knowledge of post-dispersal seed fates and other regeneration characteristics is crucial for predicting abundances and distributions of populations and, ultimately, community species composition and diversity. Seed fate studies, however, are rare primarily due to the difficulty of determining seed fates and causes of mortality. This thesis investigated post-dispersal seed fates...
    Resource Type:
    Dissertation
    Full Text:
    , Mark V. Wilson, Kenneth B. Johnson, Patricia S. Muir, Donald B. Zobel, and Jeffrey C. Miller, for

  • Diagnosis and Etiology of a Soilborne Disease Complex of Winter Squash (Cucurbita maxima) in the Willamette Valley, OR

    Creator:
    Rivedal, Hannah M.
    Abstract:
    Winter squash (Cucurbita maxima) grown in Oregon’s Willamette Valley for edible seed, frozen foods, and fresh markets is susceptible to an undiagnosed soilborne disease. Diseased squash fields exhibit symptoms of stunting, root and crown rot, vascular discoloration, and late-season wilt, which in extreme cases can lead to total crop failure....
    Resource Type:
    Dissertation
    Full Text:
    , B) crown, and C) roots of diseased cucurbit plants. Scale ranges from: ‘1’- no yellowing

  • A comparative study of temperate Chamaecyparis forests

    Creator:
    Hawk, Glenn M.
    Abstract:
    The objectives of this study include: (1) analysis of Chamaecyparis lawsoniana, C. taiwanensis, and C. formosensis forests including the structure, composition, and dynamics of plant communities and their environmental relationships; and (2) comparison of the temperate Chamaecyparis forests of Taiwan and the Pacific Northwest with emphasis on structural and successional...
    Resource Type:
    Dissertation
    Full Text:
    groups; major cities A = Taipei, B = Ilan, C = Taichung, D = Tainan, E = Hengchun, F = Taitung, G

  • Genetic variability in the eastern filbert blight pathosystem

    Creator:
    Osterbauer, Nancy K.
    Abstract:
    The heritability of resistance to eastern filbert blight, caused by Anisogramma anomala, in European hazelnut (Corylus avellana) was evaluated in the progeny of seven cultivars crossed in 12 combinations. Progeny produced by crossing 'VR6-28' with three susceptible cultivars segregated 1:1 for complete resistance to eastern filbert blight. Histograms of disease...
    Resource Type:
    Dissertation
    Full Text:
    ANISOGRAMMA ANOMALA 109 APPENDIX B: HISTOGRAMS OF DISEASE RESPONSES 115 APPENDIX C: ITS I SEQUENCE

  • Responses of forest understory plants to burial by volcanic tephra from Mount St. Helens, Washington

    Creator:
    Antos, Joseph A.
    Abstract:
    The effects of burial by tephra (volcanic aerial ejecta) on forest understory plants were examined northeast of Mount St. Helens, Washington, in the area where the 18 May 1980 eruption deposited tephra but did not destroy canopy trees. At six sites along a tephra depth gradient from 2-15 cm, understory...
    Resource Type:
    Dissertation
    Full Text:
    Abstract approved: Redacted for Privacy JDonal0 B. Zabel The effects of burial by tephra (volcanic aerial

  • Understanding Host-Pathogen Interactions in the Sphaerulina musiva-Populus Pathosystem

    Creator:
    Dunnell, Kelsey Liann
    Abstract:
    Host-parasite interactions between the pathogen, Sphaerulina musiva, and its host, Populus spp., were examined in a series of studies. In the first study, variation in resistance of Populus nigra from 7 locations in Europe was differentiated based on the parameters cankers per cm and disease severity score. The analysis evaluated...
    Resource Type:
    Dissertation
    Full Text:
    . Callan, B. E., Leal, I., Foord, B., Dennis, J. J., and Van Oosten C. 2007. Septoria musiva isolated

  • The genus Anthracobia Boudier (Pezizales, Ascomycetes)

    Creator:
    Larsen, Harold J.
    Abstract:
    A taxonomic revision of the genus Anthracobia Boudier is presented. The genus and eight included taxa are described and figured. A discussion of the taxonomic criteria used to delimit the genus and the species is included, and a key to the recognized taxa is given. Four imperfect states for included...
    Resource Type:
    Dissertation
    Full Text:
    ANTHRACOBIA BOUDIER (PEZIZALES, ASCOMYCETES) Redacted for privacyAbstract approved: William C. Denison A