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  • Susceptibility of Pacific yew (Taxus brevifolia Nutt.) to Phytophthora lateralis

    Creator:
    Murray, Marion S.
    Abstract:
    In 1991 Pacific yew (Taxus brevifolia Nutt.) was reported as a new host for Phytophthora lateralis Tucker and Milbrath which is an aggressive root rot pathogen thought previously to be specific to Port-Orford-cedar. This study was designed to compare the pathogenicity of P. lateralis on the two hosts, and to...
    Resource Type:
    Masters Thesis
    Full Text:
    successfully isolated (DeNitto, USDA Forest Service, pers. comm.). The effect of Pacific yew mortality in

  • The epidemiology of sudden oak death in Oregon forests

    Creator:
    Peterson, Ebba K.
    Abstract:
    The phytopathogen Phytophthora ramorum (Werres, DeCock & Man in't Veld), causal agent of Sudden Oak Death (SOD) of oaks (Quercus spp.) and tanoaks (Notholithocarpus densiflorus syn. Lithocarpus densiflorus), is established in coastal forests of the western United States. Since the discovery of SOD in the Douglas-fir / tanoak forests of...
    Resource Type:
    Dissertation
    Full Text:
    Service (USDA-FS, including Forest Health Protection and the Pacific Southwest Research Station

  • Phytosanitation of Douglas-fir (Pseudotsuga menziesii) logs to mitigate the risk of artificially disseminating Phytophthora ramorum within the global trade of timber

    Creator:
    Hulbert, Joseph M.
    Abstract:
    Phytophthora ramorum is a plant pathogen that was accidentally introduced to the United States. This invasive microorganism has killed over a million trees in California and Oregon, and continues to spread to new areas. Diseased areas have been nationally quarantined to prevent further spread and more than ninety countries include...
    Resource Type:
    Masters Thesis
    Full Text:
    log sections and diffusion was improved slightly through inclusion of glycol. While further research

  • Pathogenicity of Phytophthora species from Oregon waterways

    Creator:
    Navarro, Sarah M.
    Abstract:
    Described as one of the most destructive pathogens of agricultural crops and forest trees, Phytophthora is a genus of microorganisms containing over 100 known species. Phytophthora alni has caused collar and root disease in alders throughout Europe and a form of the species has recently been isolated in North America....
    Resource Type:
    Masters Thesis
    Full Text:
    .USDA Forest Service, Pacific Southwest Research Station. 378 p. Adams, G. C., Catal, M., Trummer, L

  • Phytophthora species and riparian alder tree damage in western Oregon

    Creator:
    Sims, Laura L.
    Abstract:
    The genus Phytophthora contains some of the most destructive pathogens of forest trees, including the most destructive pathogen of alder in recent times, Phytophthora alni. Alder trees were reported to be suffering from canopy dieback in riparian ecosystems in western Oregon, which prompted a survey of alder health and monitoring...
    Resource Type:
    Dissertation
    Full Text:
    Program of the USDA Forest Service, Pacific Northwest Region, began. Alder trees were

  • Biology of chlamydospores of Phytophthora ramorum

    Creator:
    Smith, Aaron Lee
    Abstract:
    The chlamydospore is a survival spore produced by 35 of the 75 described species of Phytophthora. Phytophthora ramorum Werres, de Cock & Man in't Veld, the causal agent of Sudden Oak Death (SOD), produces abundant chlamydospores in artificial culture and plant tissue. The chlamydospore is likely the most important survival...
    Resource Type:
    Masters Thesis
    Full Text:
    P. ramorum grown in V8 juice agar and broth (V8JB) and detached Rhododendron macrophyllum (Pacific

  • Port-Orford-cedar and Phytophthora lateralis : grafting and heritability of resistance in the host, and variation in the pathogen

    Creator:
    McWilliams, Michael G.
    Abstract:
    Port-Orford-cedar (Chamaecyparis lawsoniana) is a forest tree native to a small area of Oregon and California. A root disease caused by Phytophthora lateralis causes widespread mortality of Port-Orford-cedar. This dissertation examines three important elements of the Port-Orford-cedar P. lateralis pathosystem related to breeding for disease resistance: use of resistant rootstocks...
    Resource Type:
    Dissertation
    Full Text:
    Improvement Center, Umpqua National Forest, provided valuable contributions to this research. Trees used for

  • Pathological and ecological aspects of decline and mortality of Chamaecyparis nootkatensis in southeast Alaska

    Creator:
    Hennon, Paul Edward
    Abstract:
    Alaska-cedar (Chamaecvparis nootkatensIs (D. Don) Spach) is a valuable tree that is suffering from a serious decline and mortality of unknown cause throughout southeast Alaska. Epidemiological and pathological studies were initiated to determine if a pathogen is the primary cause of this problem. By examining old aerial photographs and by...
    Resource Type:
    Dissertation
    Full Text:
    . USDA Forest Service, R-6 (Pacific Northwest Region), Greensheet, Sept. 3, 1982. No. 1842. 1 p. Viereck

  • Castilleja and Pedicularis are confirmed as telial hosts for white pine blister rust in whitebark pine ecosystems of Oregon and Washington

    Creator:
    Mulvey, Robin L.
    Abstract:
    The primary objective of this research was to determine if native species within the genera Castilleja and Pedicularis are naturally infected by white pine blister rust (Cronartium ribicola) in whitebark pine ecosystems of the Oregon and Washington Cascade Range. Secondary objectives were to monitor the phenology of aecial and telial...
    Resource Type:
    Masters Thesis
    Full Text:
    Forest Service were enthusiastic sources of information, support and resources. Bryce Richardson (USDA

  • Resistance mechanisms of Port-Orford-cedar to Phytophthora lateralis

    Creator:
    Oh, Eunsung
    Abstract:
    Breeding Port-Orford-cedar for resistance to Phytophthora lateralis, a causal agent of root disease, begins by screening, through artificial inoculation, phenotypically resistant trees selected from natural stands. The successful program selected tolerant or resistant POC parent trees for the purpose of disease management. Candidate resistant POCs were used in my dissertation...
    Resource Type:
    Dissertation
    Full Text:
    update. Issue #4. USDA Forest Service. Milbrath, J. A. 1940. A Phytophthora disease of Chamaecyparis