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Filtering by: Creator Hansen, Eric N. Remove constraint Creator: Hansen, Eric N. Contributor advisor sim Hansen, Everett M. Remove constraint Contributor advisor sim: Hansen, Everett M.

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  • Distribution and prediction of Swiss needle cast of Douglas-fir in coastal Oregon

    Creator:
    Rosso, Pablo H.
    Abstract:
    This study was directed to improve our understanding of the ecology of Swiss needle cast (SNC) of Douglas-fir, a disease that produces extensive damage to forests and plantation in the coastal region of Oregon and Washington. A disease prediction model for the coastal area of Oregon was built by establishing...
    Resource Type:
    Dissertation
    Full Text:
    help, support, friendship and love. Everett Hansen, mi advisor. The members of my committee: Gay

  • 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:
    : Everett M. Hansen The phytopathogen Phytophthora ramorum (Werres, DeCock & Man in’t Veld), causal

  • Susceptibility of golden chinquapin (Chrysolepis chrysophylla) to Phytophthora cambivora

    Creator:
    Saavedra, Angel Luis
    Abstract:
    In early 2000, unusual mortality of a native North American tree, golden chinquapin, was reported by the USDA-Forest Service. Dying trees exhibited girdling cankers in the inner bark of the lower bole, branch flagging and defoliation. Isolations from necrotic tissues and soil associated with diseased or killed trees yielded Phytophthora...
    Resource Type:
    Masters Thesis
    Full Text:
    . Abstract approved:_ Everett 1\¥. Hansen In early 2000, unusual mortality of a native North American tree

  • 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:
    Abstract approved: Everett M. Hansen The chlamydospore is a survival spore produced by 35 of the

  • Factors affecting inter-tree root contact and the transmission of Phellinus weirii in young-growth Douglas-fir

    Creator:
    Reynolds, Keith M.
    Abstract:
    Groups of second-growth Douglas-fir (Mirb.) Franco were excavated in plots of two to six trees on two sites in the vicinity of Cowichan Lake, Vancouver Is., British Columbia. Eleven excavation plots provided 36 trees which could be studied in pairs (a total of 50 pairs) in order to ascertain the...
    Resource Type:
    Masters Thesis
    Full Text:
    PHELLINUS WEIRII IN YOUNG-GROWTH DOUGLAS-FIR Abstract approved: Redacted for Privacy tverett M. Hansen

  • 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:
    Mechanisms of Port-Orford-Cedar to Phytonhthora lateralis. Abstract approved: M. Hansen Breeding Port

  • 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:
    Tree Damage in Western Oregon Abstract approved: Everett M. Hansen The genus Phytophthora

  • Trichoderma spp. : distribution in stumps infested with Phellinus weirii and growth and antagonism in vitro

    Creator:
    Goldfarb, Barry
    Abstract:
    To determine which isolates will most rapidly replace Phellinus weirii in stumps and roots, Trichoderma spp. were isolated from P. weirii-infested stumps and roots, identified, and examined for growth rates and lethal effects on P. weirii in vitro. Phellinus weirii-infested Douglas-fir stumps and stump roots were sampled for microorganisms by...
    Resource Type:
    Masters Thesis
    Full Text:
    . ii Redacted for privacy Abstract approved. , Everett M. Hansen To determine which isolates will

  • 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:
    Southeast Alaaa Abstract approved: Redacted for Privacy Everett-M. Hansen Alaska-cedar (Chamaecvparis

  • 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:
    : Everett M. Hansen Described as one of the most destructive pathogens of agricultural crops and forest