Search Constraints

Start Over
Filtering by: Subject Brush -- Control -- Oregon Remove constraint Subject: Brush -- Control -- Oregon Decade 2000-2009 Remove constraint Decade: 2000-2009 Degree Name Doctor of Philosophy (Ph.D.) Remove constraint Degree Name: Doctor of Philosophy (Ph.D.)

Search Results

  • Small broomrape (Orobanche minor) biology and management in red clover (Trifolium pratense) seed production

    Creator:
    Lins, Ryan D.
    Abstract:
    Small broomrape (Orobanche minor) is a parasitic weed that attaches to the roots of red clover (Trifolium pratense). Small broomrape invasion presents a significant threat to the future of red clover seed production in Oregon. This study was conducted to investigate and develop small broomrape management options for red clover...
    Resource Type:
    Dissertation
    Full Text:
    future of red clover seed production in Oregon. This study was conducted to investigate and develop

  • Prey-stage preference in phytoseiid mites

    Creator:
    Blackwood, J. Scott
    Abstract:
    Knowledge of how individual organisms behave in their environment can provide a greater understanding of population dynamics. In a predator-prey system, the choices made by predators when foraging for prey are important aspects of behavior. Particularly in the case of a stage-structured prey population, how the predator selects prey stages...
    Resource Type:
    Dissertation
    Full Text:
    biological control drew me to Oregon for graduate school six years ago, and whose constant encouragement

  • Ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae)

    Creator:
    Campanella, Donald M.
    Abstract:
    A study consisting of three parts was undertaken to investigate how variation in species interactions, population genetic structure, epidemiological parameters, and plant breeding system may influence the ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae). Interactions between natural enemy species may modify their net effect on...
    Resource Type:
    Dissertation
    Full Text:
    . juncea are examined in response to Oregon populations of biological control organisms three decades

  • Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix) response to high intensity-short duration goat browsing

    Creator:
    Ingham, Claudia S.
    Abstract:
    The goal of this dissertation is to examine the effectiveness of high intensity-short duration goat browsing for the control of Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix), two widespread noxious weeds in the Pacific Northwest. The effects of goat browsing on Himalayan blackberry vigor, as quantified by densities...
    Resource Type:
    Dissertation
    Full Text:
    have been used for brush control and weed management throughout the western United States for

  • Analysis of hydrology and erosion in small, paired watersheds in a juniper-sagebrush area of central Oregon

    Creator:
    Fisher, Michael, (Michael Patrick), 1966-
    Abstract:
    Current research indicates that the expansion of western juniper can inhibit soil water retention, storage and prolonged releases from watersheds. This phenomenon is of great importance in eastern Oregon, as western juniper is encroaching into sagebrush/grass communities with a correlated reduction in herbaceous ground cover, resulting in reduced infiltration rates...
    Resource Type:
    Dissertation
    Full Text:
    of Hydrology and Erosion in Small, Paired Watersheds in a juniper-sagebrush Area of Central Oregon

  • Characterization, epidemiology, and ecology of a virus associated with black raspberry decline

    Creator:
    Halgren, Anne B.
    Abstract:
    The objective of this study was to characterize an unknown agent associated with decline in black raspberry (Rubus occidentalis) in Oregon. A virus was found consistently associated with decline symptoms of black raspberries and was named Black raspberry decline associated virus (BRDaV). Double stranded RNA extraction from BRDaV-infected black raspberry...
    Resource Type:
    Dissertation
    Full Text:
    in black raspberry (Rubus occidentalis) in Oregon. A virus was found consistently associated with

  • Conservation of arthropod natural enemies in broccoli with relay strip-cropping

    Creator:
    McGrath, Daniel M. (Daniel Morton)
    Abstract:
    Relay strip-cropping combines two vegetation management tactics, under-sowing and strip-management. In this study conducted from 1994 though 1997, a cover crop seed-mixture containing oats (Avena sativa L. var. "Monida"), common vetch (Vicia sativa L.), red clover (Trifolium pratense L.), annual ryegrass (Lolium multflorum Lam.), and buckwheat (Fagopyrum esculentum Moench) was...
    Resource Type:
    Dissertation
    Full Text:
    by Daniel M. McGrath A DISSERTATION submitted to Oregon State University in partial fulfillment

  • Phenology and monitoring of the cabbage maggot, Delia radicum (L.), in brassica root crops

    Creator:
    Dreves, Amy J.
    Abstract:
    In Oregon’s northern Willamette Valley, cabbage maggot (CM), Delia radicum (L.) (Diptera: Anthomyiidae) often renders Brassica root crops unmarketable. Scheduled insecticides are the only current control. Studies were conducted to: 1) describe and characterize spring emergence of CM flies and their seasonal flight activity relative to degree-day (DD) accumulations; 2)...
    Resource Type:
    Dissertation
    Full Text:
    control. Studies were conducted to: 1) describe and characterize spring emergence of CM flies and their

  • 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

  • Enhancing the predatory potential of hoverflies on aphids in Oregon broccoli fields with floral resources

    Creator:
    Ambrosino, Mario D.
    Abstract:
    Four key aspects of the relationship between predatory hoverflies and the aphid pest Brevicoryne brassicae L. on broccoli were investigated in the Willamette Valley, Oregon USA: 1) the relationship between aphid density and hoverfly oviposition, 2) the larval voracity of key hoverfly species, 3) the preferences of hoverflies and broccoli...
    Resource Type:
    Dissertation
    Full Text:
    PREDATORY POTENTIAL OF HOVERFLIES ON APHIDS IN OREGON BROCCOLI FIELDS WITH FLORAL RESOURCES. Abstract