Previous work indicated a substantial heterotic expression for grain yield existed within winter/spring hybrids of barley, This research was a continuation for the comparison of the expression of heterosis within winter/spring hybrids to the heterotic effect produced among the winter and among the spring parents. The F₁ and F₂ progenies...
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...
The effects of some soil- and foliar-borne biotic factors on
grain yield and the components of yield were evaluated using five
winter wheat varieties sown at two dates. Within each planting date,
varieties were grown under four different combinations of two soil
treatments (fumigation and nonfumigation) and two foliar treatments...
The focus of this study was to determine if S₁ family recurrent
selection might be successfully used for barley improvement.
Objectives were: 1) to identify suitable methods of evaluating grain
yield in small plots, 2) to study the effects of intermating on mean
values and variances of selected agronomic characters,...
Barley Yellow Dwarf Virus (BYDV) is a major disease of wheat. Unfortunately, unlike barley where the Yd2 gene provides adequate levels of resistance, the situation in wheat is more complex. This study was designed to provide information regarding: 1) evaluation of methods of measuring resistance among selected cultivars; 2) identification...
A great potential for increasing upland rice production exists in
the savanna soils of Colombia. These vast areas are currently
underutilized. However, they have good soil structure, flat
topography, coupled with sufficient and well distributed rainfall,
making savanna soils ideal for upland rice cropping system. The major
constraints to upland...
Concerns regarding the most effective means of evaluating
segregating generations of spring barley prompted this investigation. Three methods of selection were considered: bulk, pedigree, and single seed descent. F₆ lines derived by each method
were grown in a replicated yield trial. The effectiveness of each
method was measured in terms...
Forty-six morphological characters were used in a study of Triticum turgidum ssp. carthlicum (2n = 28) and specimens of carthlicum-like forms of Triticum aestivum ssp. vulgare (2n = 42). The morphological variation patterns within these groups were examined using stepwise discriminant analysis. These results indicate that specimens studied could be...
Equipment for strip-till planting is under development in wheat-fallow
rotations in the Columbia Basin of Oregon. This involves the
absence of tillage during the fallow season. At planting time, the
strip-till planter creates a narrow band into which the wheat seed is
placed. The area between the rows is undisturbed...
Ten wheat crosses (four winter x spring and six winter x winter)
involving F₃ and F₄ generations and their respective winter parents
were used to determine whether the early generation selection would
be effective for kernel hardness and grain protein content. In
1980, twenty individual F₂ plants were selected with...
Three chemicals SD 55446, SD 55447 and WL 84245 were found to
induce male sterility in cultivars of wheat or triticale. Both SD 55446
and SD 55447 when applied at a concentration of 0.896 kg/ha resulted
in 90% male sterility. However, SD 55447 caused female sterility at
the same concentration...
Parental and segregating populations derived from four winter x
spring wheat crosses were investigated to obtain information concerning
the inheritance and association of earliness, grain yield and yieldrelated
traits. Feasibility of selecting in early generations for these
characteristics was also evaluated. Four winter wheat cultivars
(Hyslop, Yamhill, Bezostaia 1, and...
Concerns about the genetic control and environmental influence
of various stages of development including the grain filling period,
and the relationship between early maturity and grain yield prompted
this study.
The experimental material consisted of two facultative and two
winter wheat cultivars. A dial!el cross, excluding reciprocals, was
also developed...
This study was conducted to investigate the possible contamination
of foreign pollen at different stages of a wheat breeding
program. These included spaced planted F₂ segregating populations,
replicated yield trials and seed multiplication. The experimental
wheat materials consisted of four different F₂ populations, four
cultivars and two experimental lines.
Two...
The major objective of this study was to determine why certain
winter wheat cultivars, when hybridized, will produce a greater proportion
of desirable plants in subsequent, segregating generations.
Three winter wheat parents were chosen as the experimental material,
based on their known performance as parents. Yamhill and
Pullman Selection 101...
The need to develop a shorter life cycle wheat cultivar which
would be more adapted to multiple cropping systems prompted this
study. Thus the following information was obtained.
Greatest variations in developmental patterns were found in the
stem elongation, booting, inflorescence emergence and anthesis for
five winter and five spring...
This study was undertaken to see if a method of handling
segregating populations could be employed which combined the positive
attributes of the traditional pedigree and-bulk methods. Derived F₅
lines from the pedigree, bulk, and what is identified as a modified
bulk method, were obtained from three winter wheat crosses....