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Filtering by: Subject Pear -- Diseases and pests -- Oregon Remove constraint Subject: Pear -- Diseases and pests -- Oregon Academic Affiliation Botany and Plant Pathology Remove constraint Academic Affiliation: Botany and Plant Pathology Degree Level Doctoral Remove constraint Degree Level: Doctoral

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  • The relationship of phloem graft union responses to pear decline

    Creator:
    Ostrowski, Richard Carl
    Abstract:
    Since 1948, pear decline has been responsible for the devitalization and death of many pear trees in the Pacific Coast states and British Columbia. Use of anatomical abnormalities of the graft union as a diagnostic technique to separate pear decline from other disorders exhibiting similar symptoms was evaluated. Modifications in...
    Resource Type:
    Dissertation

  • The disease cycle of side rot of pear, caused by Phialophora malorum

    Creator:
    Sugar, David
    Abstract:
    Potential sources of inoculum of Phialophora malorum were investigated. P. malorum was found to be a soil-borne fungus whose role as a postharvest pathogen of pear is dependent upon passive dispersal with infested soil. P. malorum survived in soil under a wide range of conditions, with greatest survival in cool,...
    Resource Type:
    Dissertation
    Full Text:
    Botany and Plant Pathology presented on December 1, 1989. Title: The Disease Cycle of Side Rot of Pear

  • Epidemiology of disease caused by Pseudomonas syringae as an epiphyte and its frequency, distribution, and characteristics as an endophyte of pear

    Creator:
    Whitesides, Steven K.
    Abstract:
    Conditions were established for inducing pear blossom blast caused by Pseudomonas syringae (Ps) on both attached and detached shoots. The incidence of disease was proportional to the log of Ps population under optimal temperature, moisture and bloom developmental stage. Highest incidence of infection followed occurrence of a major exotherm in...
    Resource Type:
    Dissertation
    Full Text:
    . Ps is a bacterium that causes a disease of pear and many other hosts. It can be isolated readily

  • Studies on the etiology and epidemiology of bull's eye rot of pears

    Creator:
    Henriquez, Jose Luis, 1961-
    Abstract:
    The objective of this dissertation is to introduce low-cost processing methods for the fabrication of ZnO transparent thin-film transistors (TTFTs). A novel method for depositing ZnO body layers via spin-coating of a zinc nitrate-based spin solution is presented. The processing conditions of spin-coated ZnO are optimized to produce continuous and...
    Resource Type:
    Dissertation
    Full Text:
    Columbia, Oregon and Washington. The disease is also important in Europe; in Germany bull's eye rot is

  • Brown rot of sweet cherry in western Oregon

    Creator:
    Gashaira, Bashir
    Resource Type:
    Dissertation
    Full Text:
    materially reduces the yield by causing blossom blight and fruit rot of stone fruit trees in western Oregon

  • Coniothyrium rose canker in Oregon

    Creator:
    Intrama, Siriphong
    Abstract:
    An isolate of Coniothyrium obtained from a stem canker on Nocturne rose from the Botany Department Farm, Corvallis, Oregon was studied with respect to morphological and cultural characters, pathogenicity and mineral nutrition. The hyphae of the isolate were smooth, septate and branched. The hyphal cells averaged 16.37 X 3.52 microns....
    Resource Type:
    Dissertation

  • 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:
    another Phytophthora species could be causing disease in western Oregon, and that this disease would go

  • Forecasting Pseudocercosporella herpotrichoides foot rot of winter wheat

    Creator:
    Grybauskas, Arvydas P.
    Abstract:
    The use of fungicides for the control of foot rot of winter wheat, caused by Pseudocercosporella herpotrichoides (Fron) Dei., requires a forecast of disease risk to optimize this management practice ecologically and economically. Foot rot occurs in both the mild, wet (100+ cm, ppt./year) annual cropped areas in western Oregon,...
    Resource Type:
    Dissertation
    Full Text:
    fields from eastern and western Oregon. The best predictor of end-of-season disease severity from data

  • Effects of intercropping beans with maize on angular leaf spot and rust of beans

    Creator:
    Boudreau, Mark Alan, 1958-
    Abstract:
    Experiments were performed to determine the nature of maize influence on bean disease in additive-type intercrops. Overall effects of intercrops on angular leaf spot (caused by Phaeoisariopsis griseola) in Kenya indicated >23% reductions (P<0.05) in area under the disease progress curve (AUDPC) in two of three season-site combinations. Fertilization tended...
    Resource Type:
    Dissertation
    Full Text:
    ), pest control, efficient use of nutrients, and, of interest to us here, disease control (14). One must

  • Biology of sweet cherry powdery mildew

    Creator:
    Calabro, Jill M.
    Abstract:
    The Pacific Northwest has become one of the nation’s premier sweet cherry, Prunus avium, production areas. As production of sweet cherries has flourished in Oregon and Washington, so has powdery mildew, caused by the fungus Podosphaera clandestina, which infects both foliage and fruit causing severe economic damage to growers. Sweet...
    Resource Type:
    Dissertation
    Full Text:
    , Prunus avium, production areas. As production of sweet cherries has flourished in Oregon and