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Filtering by: Subject Douglas fir -- Fertilizers Remove constraint Subject: Douglas fir -- Fertilizers Committee Member Hansen, Everett Remove constraint Committee Member: Hansen, Everett Degree Field Entomology Remove constraint Degree Field: Entomology

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  • Insects associated with black stain root disease of Douglas-fir in western Oregon

    Creator:
    Witcosky, Jeffrey John
    Abstract:
    The root systems of Douglas-fir trees infected with Verticicladiella wagenerii and assigned by crown color and terminal growth characteristics to several stages of decline were excavated at three widely separated sites in the Coast Range of Oregon. Data were gathered on insect species present, extent of colonization of the root...
    Resource Type:
    Masters Thesis
    Full Text:
    Douglas-fir in western Oregon AN ABSTRACT OF THE THESIS OF Jeffrey John Witcosky for the degree of