Pea streak virus (Marmor trifolii Holmes) is widespread and
occasionally destructive in Eastern Oregon and Washington, and in
many other pea growing areas. Since control by the use of insecticides
to kill the insect vector is only partially successful, resistant
varieties of peas are needed.
In a study to confirm...
Roots of greenhouse-grown peppermint (Mentha piperita L.) and spearmint (Mentha spicata L.)
plants and in vitro-grown shoot cultures were inoculated with Verticillium dahliae conidial suspensions to
study symptom development, detection, and elimination of the V. dahliae. There were significant
differences in the symptom expression of control and infected shoot cultures...
Tipburn is a widespread physiological disorder of cabbage and
lettuce, caused by calcium deficiency. Symptoms of tipburn are
necrosis on margins of outer and inner head leaves in lettuce,
whereas in cabbage it is only on margins of inner leaves. Tipburn
on outer leaves may develop early, but symptoms remain...
Effects of amount of applied water and frequency of irrigation
on head rot and yield of three broccoli cultivars were evaluated in
1987 and 1988. Two irrigation frequencies were established with a
line-source sprinkler system for 5.5 weeks during heading. The low-frequency
experiment was watered once per week and the...
Bacterial canker, caused by Pseudomonas syringae pv. syringae is
recognized as one of the greatest limiting factors in cherry production
in Oregon. Disease incidence may be decreased when susceptible
cultivars are high-grafted onto tolerant/resistant rootstocks. This
research was begun to develop a rapid screening method which could be
used to...