Previous work has shown that diuron (3-(3, 4- dichlorophenyl)-1,
1-dimethylurea) is less toxic to fall-planted wheat than to wheat
planted in the spring. Diuron has been a significant factor in increasing
yields of winter wheat grown in Oregon's Willamette Valley.
The influence of several selected environmental factors on diuron
toxicity...
Hand-defoliation was evaluated for its ability to
simulate herbivory by cinnabar moth larvae, Tyria
jacobaeae (L.) (Arctiidae) on the weed tansy ragwort,
Senecio jacobaea L. (Asteraceae). The evaluation was done
on a field population of flowering ragwort, for three
different timings (early, middle, and late season) of
damage.
In the...
Experiments were conducted to compare differences in P uptake
characteristics between two winter wheat cultivars Stephens and
Yamhill (Triticum aestivum L) as related to root morphologies.
Root length, root surface area and mean root radius were compared.
Plant roots and shoots were separately analyzed for P content.
The cultivars were...
Parents and progeny populations from a cross of 'Stephens'x 'Tibet dwarf' were grown in a spaced-planted experiment to obtain information concerning the nature of inheritance and possible associations between grain yield and the components of yield. Agronomic traits measured on an individual plant basis were: heading date, days to maturity,...
As a preliminary step toward the establishment of a
70 mm. aerial photo timber inventory system capable of
generating accurate stand tables, stock tables, and gross
volume estimates, this project focuses on the development
of a system which (1) eliminates the need to measure tree
height on the photos through...