The transmission of strawberry mottle virus (SMV) to Fragaria vesca
L. by Chaetosiphon thomasi and C. fragaefolii was studied to determine
differences between the two species. Acquisition, inoculation, and
retention phases of transmission were described. In all phases, C.
fragaefolii was found to be the more efficient vector.
Mean transmission...
Winter wheat is commonly grown in rotation with leguminous and non-leguminous crops in the Willamette Valley. For agronomic, economic, and environmental reasons it is important to understand the influence of previous crops on availability of N and other nutrients. Objectives of this study were: (1) to evaluate the effects of...
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...
Black vine weevil (BVW), Otiorhynchus sulcatus Fabricius, is a serious pest in cranberry, Vaccinium macrocarpon. Larvae feeding below the soil surface cause damage to the roots and underground stems. Knowledge is sparse in regard to the damage potential of BVW in Pacific Northwest cranberry beds. Control with insecticides is limited...
The effect of anthropogenic disturbance on river systems is gaining attention, and concerns about the state of freshwater natural resources are increasing globally, as are efforts to restore habitat that has been degraded by disturbance. In rivers, non-point source pollution affects the physical characteristics of the habitat and the endemic...
Studies were conducted in the Willamette Valley of western Oregon to evaluate the effects of plowing (7.5-15 cm deep) and disking (5-10 cm deep) in peppermint, Mentha piperita L., on the following factors: 1) emergence of adult "mint root borer", Fumibotys fumalis Guenée; 2) suppression of common groundsel, Senecio vulgaris...
Parental lines, Fi's and segregating populations (F₂, F₃ and BC's) including reciprocals were evaluated under field conditions to determine if genetic resistance per se exists for Septoria Leaf Blotch in a selected winter wheat cross. The experiment was conducted over a three year period with both natural infection and artificial...
In recent years, red raspberry production in Washington and British Columbia has been severely limited by a newly emerged virus complex that causes symptoms of crumbly fruit. The complex is comprised of three viruses: Raspberry bushy dwarf virus (RBDV), Raspberry leaf mottle virus (RLMV) and Raspberry latent virus (RpLV). Both...
A partially automated radio-tracking system with semi-continuous
azimuth data collection and XYLOG5 and MAP computer programs for azimuth
data analysis was used for studies of California quail (Callipepla
californica) at the E.E. Wilson Wildlife Area, Oregon, in 1988 and 1989.
Movements of 58 hens were monitored daily to determine nest...
The seasonal biology of the obliquebanded leafroller, Choristoneura rosaceana (Harris), was studied to improve its management in Mid-Columbia area sweet cherry orchards. Overwintering OBLR larvae began to emerge from hibernacula at bud stage 2 (side green). Most overwintering larvae emerged from hibernacula within three weeks of first bud swell and...
Garden symphylans (Scutigerella immaculata Newport) are increasingly important pests of below-ground parts of over 100 crops in Oregon. The focus of our work was to improve S. immaculata management through 1) development of a bait sampling method, 2) examination of the susceptibility of selected crops to S. immaculata feeding in...
The lingcod (Ophiodon elongatus) is an important groundfish species in both recreational and commercial fisheries of the Northeastern Pacific. It is a large, fast-growing, generalist predator of invertebrates and fishes. In response to concerns that lingcod may limit populations of rockfishes (Sebastes spp.), I compared the diets of 375 adult...
Epiphytic, planktonic and benthic diatom assemblages were investigated in Netarts Bay, Oregon. Samples were collected for a
one-year period from February 1980 to March 1981. A planktonic flora was observed only during periods of offshore enrichment when marine neritic species were abundant and were transported into the bay by tidal...
Field trials were conducted during 2001 to 2003 to investigate soil population dynamics of Meloidogyne chitwoodi, tuber symptom suppression using oxamyl, and post-harvest tuber symptom development on short-season potato varieties Russet Norkotah and Russet Nugget (San Luis Valley only). The experiments were located in the San Luis Valley in Colorado,...
Influence of abiotic and biotic factors were examined in selected
winter wheats previously identified as representing a range of
responses to septoria infection. In the greenhouse two and three
inoculations identified resistance when disease severity was assessed
either for the top four leaves or the flag leaf respectively. Kernel
number...