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...
This study was undertaken to obtain information on the quality of grass seed when windrowed at the high moisture levels necessary for obtaining maximum yields. A secondary goal was to monitor moisture and temperature fluctuations in the windrow and to relate their effects to development and deterioration of the seed....
Orchardgrass and tall fescue seed crops are commonly springplanted
in Oregon, but do not produce a marketable crop during the first
growing season. Establishing orchardgrass and tall fescue with cereal
companion crops would provide income during the seeding year and could
increase seed production profits. This study was conducted to...
Increases in wheat production due to breeding may be reaching
a plateau. The application of N-fertilizer beyond optimum levels
leads to lodging and to an increase in tiller death. The use of
plant growth regulators (retardants) may be an answer for future
increases in production.
Experiments were conducted in 1983...
Vegetation as a soil-forming factor was studied under forest
transition and grass while attempting to keep other soil forming factors
constant in the western part of the Willamette Valley, Oregon. The
physiographic units consist chiefly of the interior foothills and slopes
formed from an old basaltic flow with some interspersed...
Forest associations, secondary succession, and relationships
of plant communities to Roosevelt elk were investigated. Stratification
of vegetation into ecological units and an understanding of secondary
succession by habitat-type were a necessary first step in investigations
into browsing of conifers by elk. The study was jointly conducted
by the Oregon State...
The study was conducted over approximately 191,000 acres in central Klamath County, Oregon. The research had three objectives: first, to describe and classify the seral and near-climax vegetation by using polyclimax principles; secondly, to determine the southern extension of five plant associations and one plant associes as previously described by...
As the management of range lands is intensified or as improvement
activity is increased, a critical need is seen to refine the
understanding of the ecology of these lands. If soil surveys on range
lands are to be meaningful and useful, the relationship between the
fundamental ecological units and the...
A study was initiated in 1961 to characterize seral plant
communities in a part of the Cedar Creek drainage in the Tillamook
Burn. Stratification of vegetation into ecological units was a necessary
first step in conifer-animal damage studies supported by the
Oregon State Game Commission.
Reconnaissance information was recorded in...
The response of Canada milkvetch (Astragalus canadensis var. mortonii) to range and forest improvement practices was studied on a stand of mixed-coniferous forest which was clear -cut and burned in 1963 and 1964, respectively. The field studies were conducted on the Hall Ranch of the Eastern Oregon Experiment Station during...
The research presented in this thesis evaluated the effects of
uranyl (UO₂⁺⁺) upon the absorption of Li, Na, K, Rb, and Cl. Due
to the biological importance of Na and K, these two ions were
studied in the greatest detail.
The results of this research showed that, at UO₂⁺⁺ concentrations...
Field study with 5 tall fescue genotypes treated at the vegetative
growth stage, with 0, 0.28, 0.56, and 0.84 kg/ha of mefluidide
was initiated in July, 1980. The regrowth of these plants were again
treated at the booting growth stage in April, 1981, with the same
rates of mefluidide as...
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...
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...
Making quality and winterhardiness in barley are "ultimate" phenotypes composed of
component, quantitatively inherited traits. A 69-point genome map of the seven chromosomes of
barley was used, in conjunction with multi-environment phenotypes for grain yield and malting
quality, to determine the chromosome locations of quantitative trait loci (QTLs). A combined...