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...
Three Nelder plots of 3-year-old red alder (Alnus rubra Bong) were used for this study at the Cascade Head Experimental Forest, Oregon in the growing season of 1988 at an elevation of 330 meters. Each Nelder plot
represented a range of densities from 238 to 101,219 trees per hectare. The...
The objectives of this study were (a) to measure the amount
of cross-pollination caused by three bee species at 10, 20 and 40
rods distance from a foreign pollen source, (b) to measure the effects
of bee species, planting pattern and season on broad sense heritability
estimates for seed yield...
Tall fescue often results in poor liveweight gains. This may be accounted for by variations in perloline content, nitrogen content, or digestibility of the plant. Two groups of tall fescue plants were examined for each of these traits. These groups consisted of (a) fifteen single-crosses of a six parent diallel...
An evaluation of fabric reinforcement of the roadway
structure is made. The study includes a parametric analy
sis using layered elastic theory and a series of large
scale model tests.
The parametric. study analyzes the stresses and
strains of roadway structures with a fabric layer between
tna surface layer and...
The primary goal of this research was to determine the concentration and composition of nucleotides, as nucleoside monophosphates and nucleobases, in the underutilized reproductive organs (milt and roe) of Alaska pollock (Gadus chalcogrammus) and yellowfin sole (Limanda aspera). Changes in concentrations of these nucleotides and nucleotide analogs were observed with...
A study was conducted on German velvetgrass (Holcus mollis L.), a weedy, rhizomateous perennial grass introduced in the
United States in relatively recent years, The purpose of this study
was to learn more about its distribution, growth habits, and control
under conditions found in Western Oregon. German velvetgrass infestations of...
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...
Investigations were conducted to (1) determine the original
pattern of deposition and thickness of ash in the Ochoco and Blue
Mountain areas of Oregon, (2) determine if discontinuities exist in
the parent material of these soils, (3) determine the degree of mixing
of ash with other materials and evaluate reworking...
Two cultivars of tall fescue (Festuca arundinacea
Schreb.) with contrasting growth habits were studied under
field and growth chamber conditions. Fawn, an established
cultivar since 1964, and TFM, an experimental line, were
observed to grow better during spring and fall months
respectively, in the field. Different temperature regimes
of 10/4,...
Procedures were developed for assaying the biosynthesis of (-)-
kaurene-¹⁴C and other intermediates in gibberellin (GA) synthesis
from mevalonic acid-¹⁴C in cell-free enzyme extracts of immature
pea (Pisum sativum L. cv. Alaska) seeds. This system was utilized
to investigate three aspects of GA biosynthesis: (1) apparent capacities
for (-)-kaurene biosynthesis...
A numerical model, simulating the complex behavior of reinforced soil walls using the finite element method, was developed to evaluate the behavior of a surcharged, geosynthetic-reinforced retaining wall with modular block facing. A nonlinear elastic-plastic constitutive soil material model was calibrated to experimental plane strain test data, while the performance...
A sequence of soil profiles was sampled along a climate-vegetation transect on the dated Mazama pumice fall in central
Oregon. The <2 μ size fraction from each sample was characterized
with respect to the relative significance of amorphous and
crystalline components, and the individual minerals of the latter
group were...
Pre-Tertiary metamorphic rocks, Jurassic granitic intrusions,
and Eocene basalts are exposed along the North Fork of the John Day
River at its confluence with Granite Creek. Geochemical and textural
evidence suggest greenschist-metamorphosed, strongly sheared,
volcanogenic rocks originated in an island-arc environment. These
greenstones were apparently intruded during the Late Permian...
Bacterial contamination is one of the most important problems
both in plant tissue culture research and commercial laboratories. Early
detection of contaminants saves time, effort, and money. Strawberry
runner explants were screened for contaminants during June to August,
1994 and 1995. Most contaminants found were bacterial rather than
fungal. Bacterial...
Total copper concentrations of 10 [mu]g/l to 100 [mu]g/l appeared to
alter the predator-prey interactions of fathead minnows (Pimephales
promelas) and Daphnia pulex. The effect of copper concentration on
the total amounts of D. pulex consumed over a 12-h period varied with
the density of prey stocked hourly in the...
In regions where soil temperatures limit plant growth, artificial
soil warming may be an economically feasible practice. This hypothesis
was evaluated in a soil warming experiment near Corvallis, Oregon.
This experiment was prompted by the observation that multiple
use of waste heat discharged in the condenser cooling water of thermal...
A three-year investigation was conducted during 1980-1982 to
evaluate the potential of using herded sheep as a silvicultural tool
to suppress brush in Douglas-fir (Pseudotsuga menziesii) plantations
of Oregon's Coast Range. Sheep browsing of Douglas-fir was highest
in May soon after bud break. Averaged over the 2 years of grazing,...
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...
The Northern Rubber Boa (Charina bottae) is a small, secretive boa native to the Pacific Northwest. Despite this being possibly the highest latitude boas and one of only two boas native to the continental U.S., it has received surprisingly little attention. Most of the research on the natural history of...
The ringtail (Bassariscus astutus) is a small, nocturnal, meso-carnivore that occupies mid-elevation forests in the southwest portion of Oregon. Ringtail are fully protected within Oregon, but a species of conservation concern as they may be vulnerable to habitat loss and fragmentation. Limited data exists regarding ringtail ecology in forested ecosystems,...