Subterranean clover (Trifolium subterraneum L.) seed production
practices in Oregon are different from those in Australia.
There, seed is produced on fields which are managed primarily for
forage. In Oregon, seed fields are managed for seed as the primary
product and forage is of secondary concern.
Some sheep grazing is...
Germinating seeds often encounter stress conditions
of temperature, moisture and oxygen in the field.
Germination tests conducted under these stress conditions
in the laboratory might be methods of differentiating high
and low vigor seeds.
The objectives of this study were to (1) determine
if these stress conditions reduce germination performance...
Two experiments were conducted to determine the effects of
moisture stress on physiological changes that occur during the vegetative
and reproductive stages of the wheat (Triticum aestivum L.)
plant, and to relate these effects to seed yield, quality and performance.
In a field experiment, different levels of moisture stress were...
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...
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...
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...
Seed moisture is a primary factor influencing seed quality during harvesting, storage, and marketing of grass seed. However, the Association of Official Seed Analysts' Rules for Testing Seeds do not contain methods for moisture testing. The oven methods in use by seed testing laboratories in the U.S. are diverse and...
Seed vigor tests have been developed to evaluate the relative ability of seed lots to produce stands of seedlings in the field. Some workers have suggested the possibility of differentiating vigor levels by germinating seeds under osmotic stress, but have not conducted field trials to evaluate the usefulness of the...
Some perennial grass seed crops such as red fescue (Festuca rubra
L.) do not produce a profitable seed crop during the first growing
season. The present establishment method in Oregon for red fescue seed
crops generally entails spring planting which does not satisfy
vernalization requirements for seed production in the...
This study was undertaken to standardize and evaluate the
tyrosinase test as a variety identification procedure for wheat. The
potential value of the tyrosinase test lies in its ability to quantify
the colored products, rather than relying on visual estimation as
in the phenol test.
The specific objectives of this...
Germination of meadowfoam (Limnanthes alba Benth.) seed is inhibited by warm soil temperatures. This has led to recommendations for planting from early to mid-October when soil temperatures are below about 15°C. Objective data on the effects of planting date on stand establishment and yield are not available. These studies were...
Tests were carried on in growth chambers and in the field to
determine if the harvest of daylength-sensitive long-day cereals
grown during the winter in Arizona could be hastened 30 days by the
use of night interruption.
Two durum lines which were near-isogenic for sensitivity to
daylength were used throughout...
The purpose of this study was to evaluate the effect of seed
protein content on plant growth of barley (Hordeum vulgare L. )
and wheat (Triticum aestivum L. ). The effects of nitrogen application
on chemical and morphological characteristics of the seed
were also studied.
Seeds of 'Casbon' winter barley...
The objective of this research was to identify the
optimum cultural practices for the production of the highest
quality wheat seed in Oregon. The production methods
included locations, irrigation, N levels and seeding rates.
The seed quality factors studied were seed weight, bushel
weight, protein content and seedling vigor.
Foundation...
The objective of this study was to develop a soaking and drying
procedure to stimulate the germination and seedling emergence of
orchardgrass (Dactylis glomerata L.) and Kentucky bluegrass (Poa
pratensis L.) seed. Some of the physiological changes associated
with the soaking and drying treatments were also studied.
The seed was...
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....
Meadowfoam (Limnanthes spp.) is a potential oil seed
crop being developed for commercial production in the
Willamette Valley. The seeds are characterized by poor
germination at warm temperatures. It would be desirable
to overcome this temperature-related dormancy problem so
that better stand establishment could be realized from
early fall planting....
The objective of this study was to investigate ryegrass seedling characteristics that, by themselves, or combined with presently known characters, could improve varietal identification tests. Thirteen characters were studied on 30 varieties of Lolium multiflorum Lam., L. perenne L., L. rigidum Gaud, and L. hybridum Hausskn., including leaf size and...
The objectives of these experiments were to determine
the feasibility of saving seed from snap bean fields in the
Willamette Valley that have been bypassed for canning and
freezing, and to study the effects of different seed production
methods on yield and quality of snap bean (Phaseolus
vulgaris L.).
Field...
The purposes of this study were to determine the effects of
temperature, nutrients, growth regulators, and culm detachment
during seed development on ryegrass seed dormancy and weight.
The effects of storage temperature on seed dormancy were also
studied.
Seed dormancy of annual (Lolium multiflorum Lam.) and
perennial (Lolium perenne L.)...
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...
There is an increasing need for development of laboratory
identification procedures for purposes of plant variety protection, seed certification, quality control and consumer protection. In the past there were fewer commercial varieties and field
testing methods based on morphological differences were used satisfactorily. These tests require several months to complete...
The objective of this study was to develop a soaking and drying
procedure to stimulate faster germination of Kentucky bluegrass (Poa
pratensis L.) seed.
The seeds were soaked in cheesecloth bags in nine chemical
solutions. The effects of temperature and time of soaking and of
aeration of the solution were...
In conventional cropping systems in the Willamette Valley, slow
establishing grass species, such as Kentucky bluegrass (Poapratensis L.) are planted in the spring and seed is not harvested
until the following year. Due to increasing annual production
costs, it is necessary to generate a cash return from each field
each...
High protein wheat seeds frequently perform better than low
protein seeds of the same variety. Protein content of seeds can be
increased by management practices, the most important of which is
rate and timing of N applications. The purpose of this study was to
determine the chemical, biochemical and physiological...
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...
There are several grape disorders that reduce fruit
set. One, millerandage, is from poor fertilization to
produce "hen and chicken" or small seedless berries; while
another, Coulure, is the failure of grape flowers to
develop into berries. A third one, inflorescence necrosis
(INec), is a disorder that should be in...
A new male sterile (MS) mutant was found in 1988 in an inbred
line of cucumber (Cucumis sativus L.) in the greenhouse of
Sunseeds Company. The mutant is characterized by normal
corolla in both male and female flowers, normal fertility in
the female, and absence of pollen in otherwise normal-appearing...
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 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...
The effect of nitrogen (N) application on seed yield of Limnanthes
alba was studied for two years at two locations. Seeding following alfalfa
(Medicago sativa L.) was compared to establishment after wheat
(Triticum aestivum L.). Treatments used were a control (no N applied),
and two rates of N (50 and...
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...