Mortality of containerized western white pine seedlings outplanted on the Bonners Ferry Ranger District, Idaho Panhandle National Forests, was probably due to extensive root infection by Fusarium oxysporum. Diseased seedlings had chlorotic foliage, needle tip dieback, and severe twisting of the needles that indicated wilting. Most root tips of diseased...
Blueberry production in Oregon is highly reliant upon the ecosystem services of native pollinators, which provide as much as a quarter of the total pollination services received by Blueberry growers. However, the health of these pollinator populations may be affected in yet unforeseen ways as growers adopt new pest management...
For nearly two decades, foresters in the Oregon Coast Range have been witnessing a substantial decease in Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco.) vigor and growth, caused by Swiss needle cast (Phaeocryptopus gaeumannii). Currently, no solutions are in sight but aerially-applied sulfur may alleviate Swiss needle cast and its...
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...
Epichloë typhina (Ascomycetes: Clavicipitaceae) is an endophytic fungus that
infects perennial Pooid grasses and is the causal agent of choke disease. It is endemic
to Europe and was inadvertently introduced into orchardgrass seed production fields in
western Oregon. Choke disease, which was first recorded in Oregon in 1996, currently
infects...
Root rot of sweet corn in western Oregon and Washington is a significant disease that
can reduce yield of intolerant cultivars of processed sweet corn by fifty percent. Root rot
is caused by a complex of soilborne organisms, including Drechslera sp., Phoma
terrestris, and Pythium arrhenomanes. Processors have adopted tolerant...