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Filtering by: Creator Mehlenbacher, S. A. (Shawn A.) Remove constraint Creator: Mehlenbacher, S. A. (Shawn A.) Academic Affiliation Botany and Plant Pathology Remove constraint Academic Affiliation: Botany and Plant Pathology License All rights reserved Remove constraint License: All rights reserved

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  • Environmental Factors Affecting Phytophthora Root Rot of Rhododendron

    Creator:
    Mestas, Angie
    Abstract:
    Phytophthora root rot decreases availability and quality of rhododendrons produced in the USA. Symptoms of Phytophthora root rot include root necrosis, leaf chlorosis, stunting, and permanent wilt. The purpose of this thesis was to better understand the impact of root damage, soil moisture, nitrogen fertilizer application, and pathogen species on...
    Resource Type:
    Masters Thesis
    Full Text:
    , Jay Pscheidt, Shawn Mehlenbacher, and also to Annie Davis, Bryan Beck, Jesse Mitchell, Marj Storm

  • Grape Powdery Mildew Management: The Interaction Between Inflorescence Stage and Fungicide Chemistry

    Creator:
    Warneke, Brent W.
    Abstract:
    Grape powdery mildew (GPM, causal agent Erysiphe necator) is the most economically important disease of grapevine in the Western U.S. Low levels of GPM infection on clusters (1-5%) can negatively affect wine sensory quality, so intensive fungicide programs are common. This may lead to problems like excessive fungicide use and...
    Resource Type:
    Masters Thesis
    Full Text:
    mechanisms being common. Some fungicides performed as expected, while others redistributed at a lower level

  • Silviculture Impacts and Population Genomics of Coniferiporia sulphurascens, the Causal Agent of Laminated Root Rot

    Creator:
    McMurtrey, Shawn
    Abstract:
    Within the Pacific Northwest, USA, root diseases of conifers are a major forest health concern. These diseases are primarily caused by basidiomycete fungi. These fungal associates play a vital role in carbon sequestration but also have a significant negative economic impact within the timber industry. As a result, research on...
    Resource Type:
    Masters Thesis
    Full Text:
    by Shawn McMurtrey A THESIS submitted to Oregon State

  • Community Ecology of Foliar Fungi and Oomycetes of Pseudotsuga menziesii on the Pacific Northwest Coast

    Creator:
    Gonen, Lilah
    Abstract:
    Pseudotsuga menziesii var. menziesii (coast Douglas-fir) is a tree of ecological, economic, and cultural value in its native North American Pacific Northwest (PNW) distribution. P. menziesii is host to a variety of well-documented endophytic foliar microorganisms, including the fungus Nothophaeocryptopus gaeumannii, the causal agent of Swiss needle cast (SNC), and...
    Resource Type:
    Masters Thesis
    Full Text:
    write a manuscript, how to use the cluster, and how to ask stupid questions; and finally Shawn

  • Insights into the pathology and epidemiology of Phytophthora ramorum, causal agent of sudden oak death

    Creator:
    Daniels, Hazel A.
    Abstract:
    Sudden oak death is caused by the clonally reproducing generalist oomycete Phytophthora ramorum. The pathogen can infect more than 130 different plant hosts including Quercus spp., Larix kaempferi, and Notholithocarpus densiflorus, as well as common nursery genera such as Rhododendron and Camelia, where it causes symptoms ranging from bleeding cankers...
    Resource Type:
    Dissertation
    Full Text:
    asked regarding management, epidemiology, and pathology of the disease. The first chapter is a review

  • Landscape Genomics and Climatic Responses of Willamette Valley Alders

    Creator:
    Kral, George L.
    Abstract:
    The climate of the Pacific Northwest is in flux, and existing forest ecosystems are stressed and poised to shift in fundamental ways, with or without human intervention. This dissertation probes the nature of forest responses to environmental change through investigations of morphology and genetics of three species of alder co-occurring...
    Resource Type:
    Dissertation
    Full Text:
    Willamette Valley is dominated by a single plastid lineage which is subdivided into geographically

  • A G-type Lectin Receptor-like Kinase Associated with Septoria Canker Resistance and Susceptibility Described using Multi-omics and Biotechnology

    Creator:
    Lenz, Ryan R.
    Abstract:
    Managers of forest and plantation ecosystems are encountering growing problems involving plant pathogens and the expanding geographic ranges of these pathogens. Historically unexposed stands are exceptionally vulnerable when a non-native pathogen is introduced because these pathogens can cause devastating disease in a host population that lacks co-evolved resistance mechanisms. One...
    Resource Type:
    Dissertation
    Full Text:
    that differentiate the response to S. musiva between a resistant and susceptible P. trichocarpa

  • Epidemic Dynamics of Sudden Oak Death in the Forests of Oregon

    Creator:
    Carson, Adam
    Abstract:
    Sudden Oak Death (SOD) is a forest disease caused by the oomycete pathogen Phytophthora ramorum, and infects trees in the Western United States and Europe. This generalist pathogen can infect over 130 species of plants, and causes rapid mortality in tree species in the Fagaceae. Sexual reproduction is thought to...
    Resource Type:
    Masters Thesis
    Full Text:
    vitro. Mycological Research. 108:823–827. Brasier, C. M., Denman, S., Rose, J., Kirk, S. A., Hughes

  • Comparative epidemiology of Phytophthora diseases of Rhododendron

    Creator:
    Taylor, Clare Rebecca
    Abstract:
    Rhododendron species are host to many Phytophthora species and are an important crop in the nursery industry. The foliar epidemiology of twelve Phytophthora diseases on Rhododendron was studied in field and growth chamber experiments on two Rhododendron cultivars. The relative aggressiveness of Phytophthora spp. was assessed using disease incidence, severity,...
    Resource Type:
    Masters Thesis
    Full Text:
    graduate studies committee, Walter Mahaffee, Chris Mundt, Everett Hansen and Shawn Mehlenbacher for

  • Genome Organization in the Ectomycorrhizal Truffle Rhizopogon vesiculosus

    Creator:
    Lu, Dabao Sun
    Abstract:
    Rhizopogon vesiculosus is a common ectomycorrhizal (EM) symbiont of Pseudotusga menziesii (Douglas-fir) in the coast range of the Pacific Northwest. The species has been studied for its systematics, genet size, population structure, and competitive ability in several field and experimental studies. This thesis seeks to provide a more thorough characterization...
    Resource Type:
    Masters Thesis
    Full Text:
    vesiculosus is a common ectomycorrhizal (EM) symbiont of Pseudotusga menziesii (Douglas-fir) in the coast