Deliberately underirrigating a crop may yield economic
benefits. The optimal use of water by an irrigator
should be achieved under a deficit irrigation regime. It
is important to know how water deficits affect yields and
the interaction of the deficits with the scheduling of
irrigations.
A field experiment was conducted...
The volatile flavor fraction of lightly milled wheat grown in
eastern Oregon was isolated for study by two methods: steam distillation
under vacuum and steam distillation at atmospheric pressure.
The sample obtained under vacuum was extracted with ether
which was then evaporated to yield the desired wheat essence.
Steam distillation...
The effect of cooked wheat bran on the excretion of
fecal nutrients, fecal weight, and transit time was investigated
in 10 men, aged 20 to 35 years. The study was
divided into three 18-day periods. The subjects were
divided into two groups; one received the basal diet supplemented
with 15...
Kura clover (Trifolium ambiguum M. Bieb.) is slow to establish and
has low seed yields the year after establishment. Intercropping a cereal
grain during clover seed field establishment could provide additional
revenue to seed growers, provided that intercropping did not jeopardize
future clover seed yields. Factorial combinations of spring- and...
Disease has been implied as an important selective
force acting in plant populations. This study was
conducted to determine the effects of stripe rust (Puccinia
striiformis) on the population dynamics of wheat (Triticum
aestivum) cultivar mixtures.
Five wheat cultivars were grown in pure stands and all
possible mixtures at three...
A series of experiments were conducted from 1983 to 1985 to
determine the effects of dinoseb [2-(1-methylpropyl)-4,6-dinitrophenol]
on winter wheat (Triticum aestivum L. em Thell) yields. Field trials
on dinoseb timing and dinoseb plus supplemental pesticides were
established in an effort to elucidate the possible factors involved in
the yield...
Farmers and researchers are aware of spatial variation in
grain yield within farms or fields. Fertilizer management may be
improved if techniques can be developed to identify grain yield
variations in wheat fields. Aerial color infrared (CIR)
photography was used to identify winter wheat (Triticum aestivum
L.) canopy biomass variability...
Germination of immature (Stage III) and mature (Stage V) wheat (Triticum aestivum L. var. Chinese Spring and Yamhill) embryos is prevented by the inclusion of 10⁻⁴ M abscisic acid (ABA) in culture medium. In addition, Stage III embryos develop into mature embryos in culture medium containing ABA. In the absence...
Nitrogen deficiency during the winter where winter wheat
(Triticum aestivum L.) follows wheat and large amounts of straw
have been plowed down has been a factor limiting yield in the
Willamette Valley of western Oregon. Field experiments were
established to determine if an application of N on the stubble or...
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...
The nature of inheritance and possible associations for traits
influencing earliness and grain yield were investigated using a four
parent diallel of winter and spring wheat cultivars.
More genetic variability was observed for the traits measured in
segregating populations resulting from crosses between winter and spring
type wheats in contrast...
Dryland winter wheat in eastern Oregon is usually subjected to
water stress several times during the growing period. Moreover, the
last three months of growth period depend strongly on the available
soil water. The fertility level, stage of growth, availability of
soil water and climatic conditions all interact to determine...
Stand establishment plays a significant role in the development
and yield of winter wheat (Triticum aestivum L.). Availability of
soil moisture to the germinating seed is one of the most critical
factors affecting stand establishment. Water injection is a method
of applying supplemental moisture to the soil in direct contact...
Wheat endosperm morphogenesis was studied by light microscopy
during the entire growth period of anthesis to maturity. Four
developmental stages have been described in this thesis: (1) double
fertilization, (2) formation of the lower endosperm cells, (3)
termination of nuclear divisions, and (4) initiation of protein
bodies.
The first manuscript...
Visual selection for grain yield may be a limiting factor in
identifying superior yielding genotypes in a breeding program. This
investigation was conducted (1) to compare the effectiveness of
visual selection for grain yield by three selector groups representing different levels of plant breeding experience, and (2) to
examine the...
Volunteer winter wheat (Triticum aestivum 'Daws')
severely suppressed growth of fall-planted alfalfa
(Medicago sativa (L.) 'Vernal') seedlings. Wheat
competition began soon after alfalfa emerged and continued
until the first forage harvest the following May. Alfalfa
yield at the first cutting was reduced by 1% for each day
volunteer wheat was...
Four winter wheat cultivars, Bezostaya, Maris-Hobbit, Roussalka
and Stephens, selected on the basis of the diversity of their pedigree and phenotype, were planted at Hyslop Experiment Station near
Corvallis in Western Oregon to study their performance at three
different row spacings (10, 16 and 24 cm), three seeding rates
(100,...
This investigation was motivated by the apparent increase in genetic
variability resulting from the systematic combining of gene pools
represented by winter and spring types of wheats.
It was the objective of this study to provide information regarding
the nature of this genetic variability for nine agronomic characters
in populations...