The Pacific Northwest produces over 95% of the nation’s processed red raspberries, valued at over $65 million. Two of the major soilborne pathogens effecting the production of raspberry in this region are the oomycete Phytophthora rubi, which causes root rot in red raspberry plants, and the plant-parasitic nematode Pratylenchus penetrans,...
Globodera spp. eggs go through a diapause, which remains dormant until favorable hatching conditions are reached. Because of the regulatory concerns with cyst nematodes, it is often only possible to rear eggs for research in the greenhouse. However, hatch is often lower for greenhouse-produced eggs than for eggs obtained from...
Laboratory-based methods to test egg viability include staining with Meldola's Blue and/or juvenile (J2) hatching assays using potato root diffusate (PRD). These two methods have not been tested under identical conditions to directly compare their assessments of Globodera egg viability. Using two bioassay strategies, cysts from a Glabodera sp. population...
Hyperspectral images were taken in a lab setting from wheat leaves and in situ from agricultural wheat fields and disease nursery. The goal of this research was to find infection of soilborne wheat mosaic virus in wheat for early detection using digital imagery, i.e., either hyperspectral or multispectral.
Root rot of raspberry (Rubus idaeus), thought to be primarily caused
by Phytophthora rubi, is an economically important disease in the
western United States. The objectives of this study were to determine
which Phytophthora species are involved in root rot, examine the efficacy
of different isolation methods (cane, root, and...
Finding trees and crops that are resistant to pathogens is key in preparing for current and future disease threats. In this dissertation, we analyzed the potential of using hyperspectral imaging (HSI) to find infection while identifying issues and strategies addressing differences over time, in spatial resolution, the application of machine...
One of the most commonly encountered plant-parasitic nematodes in eastern Washington Vitis vinifera vineyards is Meloidogyne hapla; however, limited research exists on the impact of this nematode on V. vinifera. The objectives of this research were to determine the impact of M. hapla on Chardonnay and Cabernet Sauvignon vine establishment...
Globodera ellingtonae was detected in Oregon in 2008. In order to make decisions regarding the regulation of this nematode, knowledge of its biology is required. We determined the host status of a diversity of potato (Solanum tuberosum) varieties in soil-based experiments and identified hatching stimulants in in vitro hatching assays....
Pythium species are common soilborne oomycetes that occur in forest nursery soils throughout the United States. Numerous species have been described from nursery soils. However, with the exception of P. aphanidermatum, P irregulare, P. sylvaticum, and P ultimum, little is known about the potential for other Pythium species found in...
The most commonly encountered plant-parasitic nematodes in eastern Washington Vitis vinifera vineyards are Meloidogyne hapla, Mesocriconema xenoplax, Pratylenchus spp., Xiphinema americanum, and Paratylenchus sp.; however, little is known about their distribution in the soil profile. The vertical and horizontal spatial distribution of plant-parasitic nematodes was determined in two Washington V....