A series of field experiments was conducted during 1975 and
1976 to examine peppermint tolerance and Canada, thistle response to
Dowco 290 (3, 6- dichloropicolinic acid). Peppermint oil yield and
Canada thistle density were considered most important in evaluating
experimental results.
Peppermint tolerance to Dowco 290 was studied in weed-free...
Hop varieties were compared under field and greenhouse conditions to determine their relative susceptibility to the twospotted spider mite, Tetranychus urticac Koch. A fertility schedule was prepared for mites on resistant and susceptible varieties, and tests were conducted to compare sex ratio, oviposition rate, survival rate, and developmental rate of...
A light and electron microscope study of Corylus avellana L.
vegetative buds infested with the eriophyoid mites, Cecidiophyopsis
vermiformis Nal. and Phycoptella avellanae Nal., is reported. Descriptions
are given of changes in infested stipule tissue. The
nipple-like proliferations (enations) which arise on the infested
stipule surface are covered by a...
Benomyl-tolerant Botrytis cinerea was found in snap
bean fields throughout the Willamette Valley while no tolerant
isolates of Whetzelinia sclerotiorum were detected.
Thirty-five benomyl-tolerant isolates of B. cinerea had
slower radial growth rates than eighteen benomyl-sensitive
isolates. Sporulation of an aggressive tolerant isolate
was not stimulated when grown on benomyl-treated...
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...