Diurnal changes in stem circumference at the 1954 and 1963 internodes of a 22-year-old Douglas-fir were monitored using automated
band dendrometers. Determinations of internal tree water potential and estimates of transpiration were used to characterize the water status of the tree. Environmental monitoring included the measurement
of air temperature along...
Victoria blight of oats is caused by the fungus Cochhobolus victoriae. This fungus is pathogenic due to its ability to produce the host-selective toxin victorin. Previously, a 100-kD protein that binds victorin in vivo only in susceptible genotypes was identified as
the P protein of the glycine decarboxylase complex (GDC)....
Winter squash (Cucurbita maxima) grown in Oregon’s Willamette Valley for edible seed, frozen foods, and fresh markets is susceptible to an undiagnosed soilborne disease. Diseased squash fields exhibit symptoms of stunting, root and crown rot, vascular discoloration, and late-season wilt, which in extreme cases can lead to total crop failure....
A 1.5 ha mixed conifer stand in the Blue Mountains of Oregon
was intensively examined to assess the impact of logging disturbance
on soils and herbaceous vegetation. Sampling was conducted six
years after much of the timber overstory was removed in a
shelterwood cut and yarded by crawler tractor. A...
While current theories describing the insect-plant interaction
have emphasized the biochemical aspects of the relationship,
morphological components can also play a significant role in
determining which plants or tissues are susceptible to insect attack.
Xylem sap on which spittlebugs feed may lack many of the plant
compounds responsible for host...
Infiltration, soil erosion, nitrogen loss and soil profile
characteristics were measured on 36 sites representing land occupied
by Artemisia tridentata ssp. tridentate, wyomingensis, and vaseyana.
Infiltration, soil erosion, and nitrogen loss were strongly correlated
but highly variable. Soil loss, but not infiltration or nitrogen
loss was significantly different between subspecies....
Rates of germination and emergence of corn were measured as
influenced by soil physical parameters using blotter paper and a sandy
loam soil as growth media. The corn seeds used were a hybrid of
Funk's (DJ7xLH93).
Experimental conditions were soil temperature of 20°C, 25°C,
30°C, and 35°C, soil water potential...
Annual applications of fresh or composted dairy manure were assessed for their effects on root rots of sweet corn and snap bean and damping-off of cucumber in a field soil. Soil biological and physical properties were measured as possible indicators of root rot suppressive potential. Regardless of amendment type or...