Rapid tiller and root production can improve seedling survival and
benefit stand establishment of perennial ryegrass (Lolium perenne L.)
in commercial seed fields. Environmental conditions after establishment
and inherent morphological factors combine to reduce the commercially
harvested yield below the theoretical potential yield.
These studies were conducted to determine if...
Orchardgrass (Dactylis glomerata L.) is an important seed crop, but unlike other cool-season perennial grass seed crops such as perennial ryegrass (Lolium perenne L.) and tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.], seed yields have not increased over time so there is considerable room for improvement. Research suggests that plant growth...
To increase efficiency of seed production, it is important to
understand the effects of nitrogen (N) fertilizer rate and time of
application. In particular, the effects on floret fertility should
be examined since only a small proportion of florets actually produce harvestable seed. For these reasons, experiments were conducted in...
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...
Open-field burning has been an effective, economical, and widespread method of post-harvest residue management in creeping red fescue seed production in the Willamette Valley since the late 1940s. However, the use of field burning has been legislatively restricted due to air quality and safety issues. The foliar-applied plant growth regulator...
Oregon is the world’s leading producer of crimson clover (Trifolium incarnatum L.) seed. Recent research has reported that seed yield has been increased in cool-season grass and red clover (T. pratense L.) seed crops with the application of trinexapac-ethyl, a gibberellic acid biosynthesis inhibiting plant growth regulator (PGR) and lodging-control...
Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] is an important forage and turf grass seed crop in Oregon. Use of the stem-shortening plant growth regulator (PGR) trinexapac-ethyl (TE) has gained broad acceptance by tall fescue seed producers in Oregon and elsewhere world-wide as an economical agent of seed yield enhancement through...
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...
Chewings fescue [Festuca rubra L. subsp. fallax (Thuill.) Nyman] is a desired turfgrass with dense sod forming capabilities and superior shade tolerance. Thermal residue management (open-field burning) has traditionally been used to remove post-harvest residue and maintain seed yield over the life of the stand. However, alternative non-thermal residue management...
Red clover (Trifolium pratense L.) seed yield can be affected by plant growth regulators (PGR) and irrigation; however, the effects of these factors on physiological maturity (PM), harvest maturity (HM), and seed quality are unknown. The objectives of this study were to: 1) determine how irrigation and trinexapac-ethyl (TE, a...
One important cool-season perennial grass seed crop grown in Oregon is fine fescue (Festuca rubra L.). Open-field burning has been used for many decades to manage pests, cycle nutrients, and stabilize yield, in fine fescue seed fields, especially as stands age. Legislative restrictions currently limit open-field burning to 6,070 hectares...
Introduction of later maturing cultivars of perennial ryegrass (Lolium perenne L.) places more seed production fields in a period of drought common to Oregon during vital stages of reproductive development. During these stages, the final yield of the crop is largely determined by the number of seeds set, and the...
Legislation to reduce open field burning in grass seed fields within the Willamette valley of western Oregon changed established production practices. In the creeping grasses such as Kentucky bluegrass (Poa pratensis L.) and creeping red fescue (Festuca rubra L.) non-thermal management resulted in reduced yield. Studies were conducted to examine...
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...
Field experiments were conducted in 2002 and 2003 in the Willamette Valley of Oregon to investigate the effects of two plant growth regulators on the growth and reproduction of the weed annual bluegrass. Previous research suggested that the plant growth regulator prohexadione-calcium hastened senescence of annual bluegrass. Another plant growth...
Hemp (Cannabis sativa L.) is a versatile crop with a wide range of pharmaceutical, commercial, and industrial uses. There is a lack of research and published studies on the ideal storage conditions and their effects on seed quality for hemp. Understanding ideal hemp seed storage conditions would reduce unnecessary seed...
Parental lines, Fi's and segregating populations (F₂, F₃ and BC's) including reciprocals were evaluated under field conditions to determine if genetic resistance per se exists for Septoria Leaf Blotch in a selected winter wheat cross. The experiment was conducted over a three year period with both natural infection and artificial...
Influence of abiotic and biotic factors were examined in selected
winter wheats previously identified as representing a range of
responses to septoria infection. In the greenhouse two and three
inoculations identified resistance when disease severity was assessed
either for the top four leaves or the flag leaf respectively. Kernel
number...
Seed shattering is a constraint to improvement of seed yield in Lolium perenne L. and as a result, seed retention is an essential trait for this valuable crop. Field studies were conducted near Corvallis, OR in two years (2017-2018 and 2018-2019) to identify genetic variation for seed retention and to...
Wheat is a staple food crop with many applications. The composition and quantity of major and minor flour components greatly influence functional dough properties, processing quality, and end-use suitability. Seven to 15% of the weight of wheat flour is protein and the gluten proteins comprise 80-85% of that. The gluten...
The hop (Humulus lupulus L.) is a dioecious, diploid (2n=2x=20) species. Triploid
hops (2n=3x=30) are easily obtained from tetraploid by diploid crosses and are preferred
because of their natural seedlessness and increased vigor. The female inflorescence is used
for flavoring beer. Because brewers require product consistency, the brewing characteristics
of...
Sod-seeding techniques offer graziers a convenient way to introduce superior grass cultivars into underproductive permanent pastures. Production loss and erosion are minimized. In conjunction with improved grazing management and fertilization, renovation can significantly improve yield and quality of pastures. Existent vegetation must be suppressed prior to introducing new cultivars. This...