Both red (Trifolium pratense L.) and white (Trifolium repens L.) clover
seed yields can be highly variable and low in western Oregon. The objectives of
this study were to: i) determine crop water requirements and supplemental
irrigation timing, and ii) quantify the effects of soil and water status on
inflorescence...
The production of barley (Hordeum vulgare L.) haploids by crossing with
H. bulbosum is a widely used tool in breeding and genetics. Certain barley
genotypes have low seed set in this interspecific cross, a phenomenon known
as partial incompatibility. Haploid production efficiency and gamete sampling
are important issues with the...
Geostatistical methods were used to find efficient and accurate means for
salinity assessment using regionalized random variables and limited sampling. The
random variables selected, sodium absorption ratio (SAR), electrical conductivity
(EC), and clay content were measured on samples taken over an area of fifteen
square miles. Ordinary kriging and co-kriging...
The CERES-Wheat Crop Growth and Development model treats temperature,
nitrogen and water stresses as limiting factors. For each day the model calculates a
stress index for temperature, N and water, compares the magnitude of the indices,
and then adjusts the calculated daily potential growth using the index of the most...
Sandy soils are among the least productive soils because of their inability to
store adequate water for plant growth. Their high percolation rate not only allows
water to move quickly beyond the root zone, but also washes nutrients below the reach
of plant roots. High evaporation occurs from the soil...
The lack of information regarding the inheritance of the duration and rate of
grain filling, and the possible relationship between grain fill and grain protein
content in wheat prompted this study.
Early maturing Chinese cultivars, 'AI Feng 2' and 'CB 83-52', and late
maturing cultivars adapted to Oregon, 'Stephens' and...
The usefulness of preplant nitrogen (N) in establishing
alfalfa in colder production areas has not been
well characterized. This study was conducted to determine
the effect of preplant N and soil temperature on
yield, percent N derived from biological nitrogen fixation
(PBNF), and shoot N concentration in alfalfa (Medicago
sativa...
Italian ryegrass growth and production from
positionally selective applications and sublethal rates of a
nonselective herbicide were compared to growth and
production when treated with diuron applied preemergence as
a broadcast treatment and safened by activated carbon
applied over the crop row. In the positionally selective
treatments, herbicide spray was...
No-tillage winter wheat (Triticum aestivum L.) grown in a
wheat-fallow cropping system has consistently produced lower grain
yields than conventionally tilled soils in the semiarid Pacific
Northwest. A 2-year study was conducted in a long-term tillage trial
at Moro, OR to determine factors responsible for differences in wheat
growth and...
Strawbreaker foot-rot is a major limiting factor to cost efficient winter wheat
production in the Pacific Northwest. Development of resistant cultivars has been
hindered by the lack of adequate levels of genetic resistance and screening techniques
which can consistently detect desired genotypes.
Studies were conducted to determine if the reported...
Potato leafroll virus (PLRV) causes yield and quality losses in
potato. PLRV is identified by plant symptoms and serological tests
such as an enzyme-linked immunosorbent assay (ELISA). A similar
serological test, direct tissue blotting assay (DTBA), was used to
detect and monitor PLRV movement in field-inoculated Russet Burbank
plants and...