Population size of Clavibacter michiganensis subsp.
sepedonicus in potato cv Russet Burbank and plant response
as affected by drought were assessed in a greenhouse
experiment. Water deficit stress and no stress treatments,
and inoculum densities of 0 or 2 X 10⁷ cfu C. m.
sepedonicus/seed piece were arranged factorially. Stem...
Field plots of cv. Russet Burbank potatoes from a
single seedlot were established at four sites over two
seasons (1985-86) in two locations in Oregon to determine
the role of water-borne inoculum of Erwinia carotovora in
plant infection. One site at each location was irrigated
from a surface-water source and...
The primary cause of "early dying" disease of potatoes in
Oregon is Verticillium dahliae; however, Colletotrichum atramentarium,
Erwinia carotovora subsp. carotovora (Ecc) and E. carotovora
subsp. atroseptica (Eca) are also commonly isolated from
diseased plants. Therefore, field and greenhouse studies were
initiated to determine the relative involvement of each pathogen,...
For the past several years vegetable growers in Oregon's Willamette Valley
have experienced reduced yields in their sweet corn plantings. We conducted
studies to 1) describe the symptomology and etiology of the disease, 2) test a root
rot rating system we developed to evaluate factors in the disease syndrome, and...
Spore dispersal gradients and pod disease gradients from point
inoculum sources of Botrytis cinerea were measured over time in two
snap bean field experiments. Laboratory grown inoculum was placed
at ground level in a 30 x 30 cm square at bloom initiation and
removed at full bloom. Dispersal of inoculum,...
Isolates of Trichoderma spp. collected from snap bean foliage were tested for inhibition of grey mold of snap beans caused by Botrytis cinerea. In a detached blossom-pod assay an isolate of Trichoderma hamatum reduced pod rot by 94% compared to the nontreated check. Control was comparable to that obtained with...
Seed piece to plant transmission of the potato late blight pathogen, Phytophthora infestans, occurred with isolates of the clonal lineages US-8 in Oregon and US-11 in Washington in field trials. Average transmission rate across potato cultivars was 0.5 and 2.4% with US-8, and 0.8 and 1.0% with US-11 in 1999...