Monilinia vaccinii-corymbosi pseudosclerotia overwinter on the soil surface and produce apothecia in early spring, providing primary inoculum for Mummy Berry Disease of blueberry. Burial under 2.5 cm of soil or the absence of light have previously been identified as critical factors preventing the development of apothecia. Mulches were applied to...
There are over 35 known virus and virus-like diseases of sweet cherry (Prunus avium), some with potential to cause severe economic impact by reducing vegetative growth, vigor, and/or quality of fruit. Oregon is the second-ranked state for sweet cherry production in the United States with 13,000 acres and $70.8 million...
Diseases can be a substantial threat to woody plant production, a major industry in Oregon. Boxwood (Buxus spp.) and rhododendron (Rhododendron subgenus Rhododendron and Hymenanthes) represent the top two broadleaf evergreen woody plants by farmgate value in Oregon. Historically, Phytophthora root rot has been considered the most destructive disease of...
Viability and dispersal of ascospores of Anisogramma anomala, the cause of eastern filbert blight (EFB) on European hazelnut, from diseased branches pruned from trees were measured. In each of two years, branches bearing stromata of A. anomala were cut in mid-December and compared to branches cut near budbreak in March,...
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...
Grapevine red blotch disease (GRBD) is caused by Grapevine Red Blotch Virus, a virus in the Geminiviridae family. Observable symptoms can manifest in red cultivars, such as leaf blades that are partially to fully red, red veins, and different combinations of the two. Previous research has shown evidence of reduced...
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...
Eastern filbert blight (EFB), caused by Anisogramma anomala (Peck) E.
Miiller, is a devastating disease to orchards of the European hazelnut (Corylus
avellana L.) in the Willamette Valley, Oregon. Host resistance is the most
desirable means of disease control. Fifty-eight hazelnut accessions, including
European cultivars and interspecific hybrids were evaluated...
Raspberries are an important commodity worldwide, with the United States (U.S.) leading fourth in global production in 2017. An important factor when shipping propagated Rubus across the globe is the security of clean plant material verified through pathogen detection methods which is vital in preventing disease spread. A raspberry virus...