Studies were conducted from 1962 to 1966 to investigate the
effectiveness of several practices in manipulating medusahead
(Taeniatherum asperum (Sim. ) Nevski) infested and/or dominated
ecosystems by releasing competition in favor of perennial grasses.
Several herbicide treatments were evaluated for selective
control of medusahead and cheatgrass (Bromus tectorum L. )...
Land useable for livestock grazing in the western United States is
diminishing because of spreading municipalities, irrigation developments,
highway construction, recreational demands and withdrawals.
Concurrently, the demand for livestock and livestock products is increasing
because of a rapidly growing population. As a result, production
from the grazing land that remains...
Two methods of separating sugars and acids of Bartlett pears
were compared to decide upon a working method for later studies
involving identification and quantitation of sugars and acids during
ripening of pears and in the production and storage of pear concentrate.
The first method involved precipitation of acids with...
Sulfur-coated urea (SCU), a slow release nitrogen fertilizer,
may be economically competitive with conventional fertilizers, but
little is known of the mechanism of urea release from SCU and the
environmental factors which affect the urea release rate. Objectives
of this thesis were: (1) to determine factors which affect the rate...
A pest management program for Tetranychus urticae Koch in Oregon
peppermint was developed based on studies of sampling, plant phenology,
population dynamics and damage thresholds.
A sample size of 45 leaves provided a confidence level of 90%
and a confidence interval of 50%. Estimation of the sample mean was
based...
Seed yield in ryegrass (Lolium spp.) is the
product of the number of fertile tillers per unit area
and seed weight per spike at maturity. These
components of yield develop through a series of growth
stages beginning with tiller bud initiation and
finishing with seed filling. Environmental conditions
during plant...
The depression of the 1930s had an early effect on the state of Oregon. A
decline in timber and agricultural production resulted in severe unemployment in the
late 1920s. State and local charitable organizations attempted to care for the
unemployed but they did not have the financial resources to do...
Relationships between soil-water stress and plant-moisture
stress were studied with respect to soil classification and cambial
activity in Douglas-fir.
The study sites were forested with Douglas-fir and located in
McDonald Forest and near Marys Peak in the Oregon Coast Range.
Soil-water depletion was followed by the use of gypsum blocks...
The purpose of this study was to investigate physical education
and sport in Thailand and, based upon expert opinion, to develop a
blueprint of physical education and sport for the nation building of
Thailand. The investigation concentrated on the history, role and
function, purpose of governmental involvement, and future prospects...
Studies were conducted to determine the nature of the interaction
between atrazine (2-chloro-4-ethylamino-6-isopropylaminos-
triazine) and magnesium on tomatoes. This interaction was
studied under two light regimes: continuous light and a 12-hour
photoperiod. Tomato plants were grown in sand cultures at three
levels of magnesium fertilization. Four weeks after planting,
atrazine...