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...
Nitrate reductase is known to be the enzyme regulating the
reduction of nitrate to nitrite in plants. This reduction is the first
and rate-limiting step in the transformation of inorganic nitrate to
a cellular nitrogen form. Since this reduction process is essential
to phytoplankton growth when nitrate is the only...
A study was conducted to compare the competitive
ability with weeds of the short-strawed Gaines variety
wheat and taller growing varieties under different fertility
levels at three experimental locations. The
experiments were designed so that the effects of
variety, nitrogen fertilization, and weed competition
could be evaluated. The interactions between...
Alnus rubra (Bong. ) seedlings were grown in sand culture and
irrigated with nutrient solution containing CdCl₂
ranging from 5 μg to 100 mg per liter. Treatment of A. rubra seedlings for 4 weeks
with 50 and 100 mg CdCl₂
per liter of nitrogen-free nutrient solution
decreased in situ nitrogenase...
Pastures consisting of mixtures of subclover (Trifolium
subterraneum) and grasses have responded to sulfur fertilization
on many sites in Douglas County, Oregon. The objectives of this
study were to examine specific changes in forage quality which occur
as sulfur is applied in excess of the amount required for maximum
yield...
A nutrient solution technique developed for wheat was used to
determine tolerance of rice cultivars to aluminum (Al) toxicity.
Pre-germinated rice seed was placed on top of a screen and allowed
to grow on the Al-free solution for 72-96 hours or until the primary
root was 2-3 cms long. Seedlings...
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....
The effects of light incident on leafy cuttings is
quite complex because' light influences several factors
which may affect root formation. One effect of light is
to influence the carbohydrate status of the cutting by
influencing photosynthesis. The role of current photosynthate
in the rooting of leafy cuttings is uncertain....
Herbicides are being used as a tool by forest managers to speed
the restocking of sites where tree seedlings face competition from
grasses for limited moisture, light and nutrients. Retarded growth
or, more commonly, death of the seedlings would occur if a selective
herbicide was not used to control competing...
The tolerance of woody plants to picloram (4amino-3,5,6-trichloropicolinic acid) has been shown by field applications to vary from mild to extreme. A laboratory study was done to investigate the basic causes for this range of tolerance known to exist among three woody plant species, Fraxinus pennsylvanics, March, (green ash) resistant,...
Spectroradiometric analyses were made to examine the light filtering capacity of coniferous forests and to establish the lower light energy limits for growth of Pseudotsuga menziesii (Mirb. ) Franco, Abies concolor (Gord. and Glend.) Lindi. and Pinus ponderosa Dougi. Visible energy(400-750 nm) was recorded at 48 points under four mixed...
Published October 1967. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
An investigation was undertaken to determine whether
potassium is indeed necessary for the in vivo synthesis of a
specific protein. The effects of univalent cations on the
inductive formation of nitrate reductase and on the level of
activity of representative non-adaptive enzyme are presented.
Cultures of Neurospora crassa were grown...
Four experiments were carried out with broiler chicks from day-old to three or four weeks of age to assess the effects of nitrates and nitrites from calcium, potassium, and sodium salts in the drinking water of broilers on growth, body weights, feed utilization, blood chemistries, liver tissues, and lipid oxidation...
Three greenhouse experiments were designed to measure the
effects of N, K and Cl on the nutrient uptake by Russet Burbank potatoes
(Solanum tuberosum). A Deschutes sandy loam soil from Powell
Butte area in Central Oregon, low in potassium, was used to study
these effects.
Nitrogen applications produced significant increases...
Field experiments were conducted with cauliflower (Brassica oleracea var.
botrytis cv. Snowball Y ) to determine crop development, yield, quality and
maturity response to various seasonal water levels, and to specific water stress
timing in relation to curd initiation. The effects of nitrogen rate, timing, and
source and the application...
Reports of previous research indicated a stimulatory effect of
triazine herbicides on growth, yield and protein content of plants and
seeds of various species.
Studies were conducted in the greenhouse, laboratory and field
to investigate the effects of atrazine (2-chloro-4-ethylamino-6-a sopropylarnino-
s-triazine) on growth, yield, seed composition, and
seed germination...
Studies were conducted to determine the extent and nature of
sub-lethal effects of herbicides on plant growth. At least one
herbicide from each major chemical class of herbicides was evaluated
under greenhouse conditions. Oat plants were grown in sand
culture to eliminate soil interferences. Herbicides were applied
pre-emergence in nutrient...
This study was initiated to determine the tolerance to copper
of Aspergillus niger, Stemphylium sarcinaeforme, Monilinia
fructicola and Fusarium oxysporum f. sp. lycopersici. Included
were strains of the latter two fungi that were induced to tolerate
relatively high levels of copper by continual culture on sublethal
levels of the toxicant....
Leaf elongation is a major indicator of plant growth. It is
controlled by complex interactions of many factors including light
intensity, photoperiod, water availability, atmospheric conditions,
and plant water stress. In this study, the response of leaf elongation
to length of photoperiod and to plant water stress as indicated by...
A study, consisting of two sequential greenhouse experiments, was
designed to determine the effects of soil liming upon the fungal
partner in a mycorrhizal association. A Willamette Valley foothill
soil, of the Jory series, was limed in increments to achieve a range
of acidity and alkalinity. The P-deficiency and P-fixing...
This research evaluated the germination and early seedling
development response of two sources of bluebunch wheatgrass (Agropyron
spicatum) to a wide range of environmental conditions. Seeds collected near John Day, Oregon and Secar seed obtained from the Soil
Conservation Service were used in the investigations.
Evaluation of the germination response...
Global atmospheric pollution from chlorofluorocarbons has the
potential of causing significant reductions in the concentrations of
stratospheric ozone. If the production of chlorofluorocarbons were
to continue into the future at the rate prevalent in 1977, the
steady state reduction in total global ozone could be between five
percent to ten...
Vegetatively propagated peppermint (Mentha piperita L., cv. Black Mitcham) was used to determine the effects of night temperatures (8°C vs 25°C) on the plant growth in terms of fresh weight and leaf area, and on metabolite contents. The plants were sampled after 14 days, 21 days and 28 days in...
Debris flows are a major cause of disturbance to riparian vegetation. Both observational and experimental studies were used to examine the initial recovery of riparian vegetation after debris flows on headwater streams in the western Cascades of Oregon. My goal was to determine the roles of seedlings and vegetative sprouts,...
Cyperus esculentus L. var. esculentus is a serious weed
problem in northwest Spain. Long-term control from glyphosate and
other herbicides has been inconsistent. Field, greenhouse, and
laboratory studies were conducted on factors influencing the
activity of glyphosate on C. esculentus.
In field studies, glyphosate controlled foliage growth at most
growth...
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...
The plant hormone auxin regulates many aspects of plant growth and
development. At the cellular level, auxin can stimulate cell division, cell elongation, and
cell differentiation. Little is known about the molecular mechanisms that mediate auxin
action at this level, although changes in gene expression have been implicated in each...
Investigation was made into the influence of changing light
intensity on the organic and elemental composition of two species of
marine diatoms, Ditylum brightwellii and Skeletonema costatum.
Analysis was made of the relative changes in soluble and insoluble
carbohydrate; polar, non-polar, and total lipid; amino acids; proteins;
and total carbon,...
Purple nutsedge [Cyperus rotundas L.) has been recognized as one of the
most troublesome perennial weeds of agricultural lands in tropical and some
temperate regions. This research sought to determine the effects of timing of
herbicides, shading, and soil moisture on plant population growth and tuber
production of purple nutsedge...
The dynamics of N was studied in field grown Comice/Provence
quince BA29 pears in Medford, Oregon. Total tree biomass, N content,
and ¹⁵N evaluations suggest that young pears require little N (48 kg
N ha⁻¹ yr⁻¹). About 45% of total tree N present in dormant trees was
remobilized into new...
In onions, sensitive cultivars diminish the usefulness of the selective
herbicide bromoxynil. Tolerant cultivars can overcome this limitation. A better
understanding of the biochemistry, physiology and genetics of bromoxynil
tolerance could lead to improved weed control programs in onions.
Onion cultivar response to bromoxynil was studied under greenhouse
conditions. Tolerant...
Bean shoot parts that respond to glyphosate (N-
(phosphonomethyl)glycine) in ways useful for bioassay were determined
by applying glyphosate doses of 3.8 to 60.3 ug ae per plant to the
simple leaves when the first trifoliolate leaflets were about 1 cm
long. Dry weights of parts that were almost fully...
Several studies of herbaceous perennials have addressed the effects of environmental factors during and after production, inherent cold hardiness, and post-harvest handling procedures to enhance flowering and growth during establishment. The regrowth of both woody and herbaceous forage plants following establishment is reported to be directly related to reserve-nitrogen content....
Published July 1941. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published September 1932. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Spectral patterns of three brush species under the influence of herbicide treatment were investigated to evaluate the effectiveness of monitoring forest vegetation management using ground-based and remote sensing techniques. Foliage of Pacific rhododendron (Rhododendron macrophyllum D. Don), golden chinkapin (Castanopsis chrysophylla Dougl.), and hairy manzanita (Arctostaphylos columbiana Piper) sprayed with...
This study was designed to learn the effect a specific herbicide practice on plant communities. Data were obtained from brushfields that had been aerially sprayed with 2,4-D (2,4 dichiorophenoxyacetic acid) and/or 2,4,5-T (2,4,5 trichlorophenoxyacetic acid). Qualitative data on species composition, cover percent, height, response to herbicide and site description were...
An apparatus was designed to permit freezing tests of
needles and other tissue parts from coniferous trees under
controlled rates of temperature change with time. The design
is based on the principle of a balanced system of refrigeration
demand and heat input to achieve a steady temperature state.
The apparatus...
Published April 1982. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Five nutritional aspects of 'Valencia' orange production in Agadir, Morocco
during 1989-1991 were evaluated: 1) the effect of N and K on yield and fruit
quality, 2) leaf sampling time and diagnostic approaches to optimize mineral
nutrition, 3) mass and mineral partitioning within individual trees, 4) K-Rb
relationships, and 5)...
Watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai var.
Crimson Sweet) was seeded in a commercial peat mix in multicell
containers (72 cells-tray⁻¹, 40 cm³-cell⁻¹) in July 1989 and April 1990.
In 1989, the medium was amended with CaC0₃ at 10% w:v. In 1990, no
CaC0₃ amendment was made. Watermelon seedling...
Transition matrix models are one of the most widely used tools for assessing population viability. The technique allows inclusion of environmental variability, thereby permitting estimation of probabilistic events, such as extinction. However, few studies use the technique to compare the effects of management treatments on population viability, and fewer still...
The effect of solution nitrogen (N) and phosphorus
(P) concentrations on biomass production and N₂ fixation
of red alder (Alnus rubra Bong.) seedlings grown in
perlite-filled pots in a climate controlled growth room
were studied. Nodulated seedlings were subjected to 12
different nutrient solution combinations of nitrogen and
phosphorus and...
The current rate of global biodiversity loss and extinctions is unparalleled and a major concern. Freshwater organisms are facing particularly rapid rates of biodiversity loss. Amphibians, which require an aquatic environment for part of their life cycle, are one of the most vulnerable vertebrate groups. Amphibians are experiencing population declines,...
The hypothesis that inoculation of transplants with vesicular-arbuscular mycorrhizal (VAM) fungi before planting into saline soils would alleviate salt effects on growth and productivity was tested on lettuce (Lactuca sativa L.) and onion (Allium cepa L.). A secondary hypothesis was that the fungi isolated from a saline soil would be...
Published December 1980. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Global increases in ultraviolet-B radiation (UVBR:290-
320 nm) resulting from decreases in stratospheric ozone
concentration have the potential to alter marine primary
production and affect global climate and marine trophic
dynamics. Effects of UVBR on phytoplankton carbon fixation
were determined from open ocean exposure studies conducted
off the coast of...
Since 1960 sheep have been used to reduce fuel accumulation on Fort Ord National Monument (FONM) grasslands. From 1997-2019 BLM’s monitoring projects were employed to determine livestock grazing impacts on Coyote Brush, bunchgrasses, and other native and non-native herbaceous vegetation. In 2014, the Bureau of Land Management (BLM) determined that...
................................................................................................................................................ 8
Types of Grazing on Fort Ord National Monument
A special apparatus was developed in which the soil moisture
levels of several soil cells could be maintained independently by
various osmotic solutions at a selected temperature. The effect of
four soil moisture suctions and four soil temperatures on the rates
of transpiration, photosynthesis and respiration of monterey pine
seedlings...
The effect of moisture stress and nutrients on the rate of growth
of wheat (Triticum aestivum L. Var. Gaines) seedlings was studied.
A special apparatus in which the moisture stress of several perlite
cells could be maintained constant by osmotic solutions was used.
Predetermined amounts of nitrogen were added to...
The relationships between avian community structure and herbicide
modification of vegetation were analyzed on early-growth clearcuts in
western Oregon that had received phenoxy herbicide treatment 1 or
4 years previously. Only minor effects of herbicide treatment were
evident 1-year after spraying, except for red adler (Alnus rubra),
which still exhibited...
Sunflower (Helianthus annuus L., cv. NK894) seedlings, grown hydroponically, were exposed to ozone concentrations of 0.0, 0.1, 0.2, and 0.3 ppm at 60% RH, or 0.0
and 0.3 ppm at 30% and 90% RH, for 6 h/d, for four consecutive days, at ages 15 to 18 days from seeding. Plant...
Previous research had identified four serogroups of Rhizobium trifolii
indigenous to Abiqua soil (fine, mixed, mesic, Cumulic Ultic Haploxerolls).
Nodulation of subterranean clover (Trifolium, subterraneum L.) by two of the
serogroups, 6 and 36, was influenced by the application of CaC0₃ to the soil.
The studies described in this thesis...
Take-all root rot (caused by Gaeumannomyces graminis var.
tritici, Ggt) is one of the major diseases limiting winter wheat
yields in western Oregon. Losses caused by take-all (TA) can be
significantly reduced through crop management and fertilization
practices.
Results from field experiments in western Oregon show that the
use of...
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...
The usefulness of preplant nitrogen (N) in establishing
alfalfa in colder production areas has not been
well characterized. This study was conducted to determine
the effect of preplant N and soil temperature on
yield, percent N derived from biological nitrogen fixation
(PBNF), and shoot N concentration in alfalfa (Medicago
sativa...
This study sought to explore the relationship between spatial scale and canopy
chemistry through the use of remotely sensed videography data and total nitrogen content
of potato petioles. A range of broad band spectral indices were employed along with
standard red and green wavelengths to define an optimum scale or...
In poplar (Populus spp.) a 32-kilodalton bark storage protein (BSP) accumulates during the fall and winter, and is thought to be a major storage form of overwintering nitrogen. BSP is induced by short-day (SD) photoperiod, and under natural conditions BSP accumulation coincides with the induction of dormancy. Because BSP accumulates...
Dormancy of 'Pinot Noir' grapevines was characterized. Primary buds
required ca 300 cumulative chilling hours (CCH) to initiate the transition from
endodormancy to ecodormancy, which occurred in mid November. Additional
chilling, up to 1000 CCH, improved budbreak. Changes in bud water content
were estimated by gravimetric and spectroscopic methods. Total,...
In the Pacific Northwest some prune cultivars often exhibit inconsistent fruit set. Several factors have been associated with this characteristic. Temperature, genotype and boron content are among the most frequently mentioned. Studies were conducted to determine the effect of fall ethephon application on flower bud growth and ovule longevity in...
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...
Bacterial contamination is one of the most important problems
both in plant tissue culture research and commercial laboratories. Early
detection of contaminants saves time, effort, and money. Strawberry
runner explants were screened for contaminants during June to August,
1994 and 1995. Most contaminants found were bacterial rather than
fungal. Bacterial...
The effects of five tillage treatments on soil bulk density and
mechanical impedance were examined on Newburg sandy loam soil in the
Willamette Valley, Oregon, in 1987. Subsequent effects on seedling
emergence and yield of carrots (Daucus carota L., cvs. Orlando Gold
and Royal Chantenay) were also measured. Mechanical impedance...