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...
A major factor limiting the efficiency of plant improvement programs is the lack of knowledge as to which parental combinations to make when working with quantitatively inherited traits. The primary objective of this study was to provide information regarding the use of combining ability analysis to predict which cross combinations...
Immature embryo explants taken eight days after anthesis were used
to establish callus cultures of spring barley. Two types of calli
were observed. A soft watery callus which produced a limited number
of shoots and a harder yellowish callus that gave rise to numerous
green primordia and shoots. Gamborg's B5...
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...
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...
Three stem rust Puccinia graminis graminicola, resistant sources of perennial ryegrass, Lolium perenne, 4A, 48A, and 77A, were crossed in a partial diallel design with one susceptible source, MP-2, resulting in six crosses excluding reciprocals. The F1's and cloned parental populations were inoculated in the field and rated on a...
This thesis consists of four chapters. Literature is
reviewed in Chapter 1. Chapter 2 describes an addition
series experiment to determine the influence of species
density and proportion on vegetative and reproductive yield
of spring wheat and Lolium multiflorum. Chapter 3 consists
of a growth analysis experiment to determine whether...
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...
Some biochemical activities in embryo or seedling of
germinating rice (Oryza Sativa L.) seed were studied to explain the
effects of suboptimum (20 C), optimum (30 C), and supraoptimum (40 C)
temperatures on seed germination and seedling growth. It was observed
that 40 C slightly speeded up seed germination but...
Glyphosate (N-(phosphonomethyl)glycine) is an effective
foliar-applied herbicide with broad-spectrum activity. Greenhouse
and laboratory experiments were conducted to determine the
importance of soil moisture, autoclaved soil, soil type, sphagnum
peat, soil pH, added phosphorus, and plant residues on crop
establishment and growth when glyphosate was applied before
emergence of the crop....
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,...
Hard Fescue (Festuca longifolia Thuill.) has potential for in
creased turf use but does not respond well to normal seed production
management practices in Oregon. Field burning (the normal residue
management practice) results in reduced seed yields in commercial hard
fescue seed production fields but stimulates seed production in Chewings...
The semi-arid regions of the Pacific Northwest are
characterized by a high degree of annual temperature and
precipitation variation. As a result of this climatic
variation, dryland nitrogen fertilizer trials on fallow-
,wheat rotations typically demonstrate a variable response.
Wheat growers in the area must not only cope with this...
A field study was conducted in 1978 and 1979 at the Hyslop Crop
Science Field Laboratory near Corvallis, Oregon, to determine the optimum
capsule harvest date of Papaver bracteatum Lind. for thebaine yield
and oil yield, while maintaining an acceptable percentage of seed germination.
Accessions PI 383309 and PI 381607...
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 effect of four basic liquid fertilizers: Solution 32, 10-34-0-.9, Thio-Sul, and Potash solution; and one commercial liquid fertilizer, Feast 9-18-9, on germination, emergence, and seedling growth of wheat (Triticum aestivum L.) were evaluated under laboratory, greenhouse, and field conditions. Experiments included: 1) preliminary study of basic fertilizer sources to...
Meadowfoam (Limnanthes alba Benth.), an open-pollinated herbaceous
winter annual, is adapted to Mediterranean climates and produces
a seed oil with industrial uses. Seed yield in meadowfoam is
partially determined by the number of seeds produced per flower. The
flower is protandrous with the stigmata becoming receptive 1-3 days
after anther...
This study was undertaken to better understand plant characteristics
related to high and low forage yield in tall fescue selections
as affected by temperature. Dry matter distribution into yield components
in three different temperature regimes was evaluated. Root
growth, dark respiration and nutrient concentration were also examined.
The four diverse...
Soil-related problems common to Oregon farmers are
erosion, compaction, organic matter depletion, and
nutrient loss. High costs of fertilizer, fuel, and weed
control are additional management problems. Growing a
secondary crop as a living mulch with a primary crop may
ease some of these problems.
Sweet corn production in Oregon...
Oregon sweet corn growers face high fertilizer, fuel
and weed control costs; soil compaction, erosion, organic
matter and nutrient depletion; and difficult equipment
operations in muddy fields. An alternative production
system might ease some of these problems.
Testing was begun to evaluate a living-mulch
cropping system for sweet corn (Zea...
Napropamide [2-(alpha-naphthoxyl)-N,N-diethylpropionamide], a
preemergence herbicide, is widely used in the United States on a
variety of tree fruits, nut crops, vegetables, and mint for annual
grass and broadleaf weed control. When napropamide has been left on
the soil surface without incorporation through irrigation or mechanical means, inconsistent results have been...
Experiments were conducted to determine: (1) effects of pretransplant
stolon formation on performance of potato transplants in
the field and greenhouse; (2) effects of parent plant nodal position
on productivity of rooted nodal cuttings; and (3) relationships
between photoperiod and stolon formation.
The effects of early stolon formation on Russet...
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...
The semi-arid dryland wheat-producing areas of the Pacific Northwest are characterized by cool, moist winters and dry, hot summers. The amount of annual precipitation is generally quite variable and inadequate for annual cropping. Where soil depth is adequate, the predominant loessal soils generally supply sufficient moisture for small grain production...
The herbicide rate required to reduce growth by 50% (GR₅₀) of 11
cultivars of red fesue (Festuca rubra L. and F. rubra ssp. commutata)
and for four cultivars of bentgrass (Agrostis tenuis Sibth. and A.
stolonifera L. var. palustris) to sethoxydim (2-[1-(ethoxyimino)
butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one) was
determined in greenhouse and laboratory experiments....
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...
Seed yield in perennial ryegrass is the product of yield components
that develop during the life of the plant. Crop yield potential is
defined by the number of fertile tillers, spikelets per spike, and
florets per spikelet. It has been shown that perennial ryegrass
realizes only a small percentage of...
A seed maturation study was conducted to determine the earliest
date seed of subterranean clover (Trifolium subterraneum L.) may be
safely harvested without reduction in yield or seed quality. In 1981
and 1982, seed and bur weight, seed and bur moisture content, germination and seedling vigor were studied to determine...
Wild proso millet (Panicum miliaceum L.) is a serious weed
recently infesting sweet corn fields in the Willamette Valley of
western Oregon. Field and greenhouse experiments were conducted to
determine the importance of seed depth in the position of the growing
point of wild proso millet seedlings and in the...
The number of varieties of ryegrass (Lolium spp.) has increased greatly in recent years. An accurate and rapid laboratory technique to identify these varieties would benefit the consumer as well as protect an organization's Plant Variety Protection rights. There is also a need for a technique to complement the seedling...
Response from nitrogen and chloride fertilization was measured
in field experiments on winter wheat (Triticum aestivum L. Em.
Thell. var. 'Stephens' and 'Yamhill') grown in western Oregon in an
environment with a range of susceptibility to take-all root rot
(Gaumannomyces graminis var. tritici Walker). Cropping sequences
and expected disease severity...
Downy brome (Bromus tectorum. L.), a serious grass weed in eastern Oregon can be partially controlled in wheat by metribuzin [4-amino-6-tertbutyl- 3-(methylthio)-as triazin -5(4H)-one]. However, cultivars of many crops Lave been reported to differ in their level of tolerance to metribuzin. This lack of tolerance has led to the investigation...
Marah oreganus, a perennial, belongs to the Cucurbitaceae family
and it is commonly known as wild cucumber. In the past, this plant
grew along fence rows, but now wild cucumber has become a weed
problem in perennial grass seed fields of western Oregon. Several
research studies were conducted to examine...
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....
The response to glyphosate [N-(phosphonomethyl) glycine] of two
dodder species Cuscuta campestris Yuncker (field dodder) and Cuscuta
indecora Chiosy (largeseed dodder) parasitizing alfalfa (Medicago
sativa L.) was compared. In the absence of glyphosate, alfalfa was
killed or severely injured by parasitism from uncontrolled dodder.
Results of field experiments in which...
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...
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...
Concerns about the possible reciprocal differences resulting from
systematic crossings of winter and spring wheat gene pools prompted
this investigation. If traits can be improved by simply reversing the
direction of a cross, then identification of the best female parent in
a cross would be helpful for breeding programs.
Two...
Grain yield and grain protein are often negatively associated in
wheat. When yield increases and grain protein decreases, there can be
an adverse effect on the milling and baking quality if the desired end
product is bread flour. It has been suggested that this inverse
association is the result of...
Four isogenic lines possessing different combinations of height
reducing genes Rht₁ and Rht₂ from 'Norin 10' were crossed to a short
stature, early maturing, septoria susceptible cultivar identified as the
'Tibet Dwarf'. The isogenic lines originated from the backcross
population of 'Itana'/3/'Norin 10'/'Brevor 14'//6*'Itana'. Parents, F₁
and F₂ generations provided...
During physiological ageing of seed potatoes, the stored tuber
undergoes certain biochemical changes which cause the breaking of
dormancy and the initiation of bud growth. The ageing process can
be manipulated through storage temperature and duration. Higher
temperatures usually accelerate seed tuber ageing. In order to
define the process of...
Rate of emergence is an important character for stand
establishment. Ability of wheat seeds to germinate and
emerge rapidly under different climatic conditions may be
regulated by physical and/or physiological characteristics.
Seeds of 26 wheat varieties representing five classes
were produced in two different environments (Moro and Corvallis,
OR). Seed...