Meadowfoam (Limnanthes alba Hartw. ex Benth) seed meal (MSM), a by-product of meadowfoam oil extraction, has a plant defensive compound known as glucosinolate glucolimnanthin (GLN). Myrosinase enzymes present in soil microbes and meadowfoam seeds can convert GLN to glucosinolate breakdown products (GBPs), which demonstrate herbicidal activity and have the potential...
Glasshouse and growth-chamber experiments were conducted to evaluate
primisulfuron phytotoxicity and the influence of adjuvants on downy brome and Kentucky bluegrass. GR₅₀ (50% growth reduction) values were 0.97 ± 0.57 and 8.07 ± 1.85 g/ha for downy brome and Kentucky bluegrass, respectively. Primisulfuron was applied to downy brome and Kentucky...
Selective suppression of crown and root sprouting of
non-coniferous cover are the keys to effective forest
vegetation management. This study 1) develops insight into
mechanisms of controlling root suckering and top regrowth of
bear clover (Chamaebatia foliolosa), and develops a broad
data base for controlling broad groups of vegetation
chemically....
Temperate climates are particularly conducive to
growth of annual bluegrass which readily invades and
dominates most cool-season turfgrasses. Ethofumesate
(2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl
methanesulfonate) is one herbicide available which will
selectively control annual bluegrass.
The primary objectives of this research were to
determine optimum application rates and timing of
ethofumesate for control of...
The behavior of six herbicides in soil was studied under controlled laboratory conditions. Sorption of bromacil, chiorotoluron and diuron was assessed by the batch equilibration procedure over a broad range of aqueous phase sorbate concentration. Linear equilibrium sorption constants (K[subscript p]) were slightly higher at 4° C than at 25°...
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...
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...
Paraquat (1,11-dimethy1-4,4'-bipyridinium ion) and glyphosate [N (phosphonomethyl)glycine] are herbicides utilized for chemical seedbed preparation in the establishment of grass and legume seed crops. When these herbicides are applied after seeding the crop, seeds which are not protected by a layer of soil could be exposed to the herbicide. Effects of...
Applications of ethofumesate in Oregon have been observed from
previous research and from commercial use to be less effective when
applied to dry soils, even if subsequent precipitation occurred
within a few days. Two field studies were established in the
summer of 1979 using sweet corn (Zea mays L. 'Jubilee')...
With the development of new selective herbicides and the frequent
change in commercial wheat cultivars, information is needed as to the
possible interaction between cultivars and herbicides. The responses
of five genotypically diverse wheat cultivars (Bezostaya, Daws, Maris
Hobbit, Stephens and Yamhill) to diuron [3-(3,4-dichloropheny1)-1,1-
dimethylurea], diclofop methyl 2-[4-(2,4-dichlorophenoxy)phenoxy]
propanoate...
HOE 23408 [methyl 2-[ 4-( 2, 4- dichlorophenoxy )phenoxy]propanoate]
is a herbicide used to selectively-control Italian ryegrass
(Lolium muitiflorum Lam.) and wild oats (Avena fatua L.) in wheat.
The objective of this research was to compare the relative importance
of foliar and root uptake of the herbicide in these two...
In previous research in Europe, asulam (methyl sulfanilylcarbamate)
was found to be a potentially useful herbicide for controlling
broadleaf dock Rumex obtusifolius L. ) in permanent pastures.
Asulam was also reported to have a low margin of safety when used
on common pasture species. Field studies were conducted in western...
HOE 23408 [ 4-(2' , 4'-dichlorophenoxy)-phenoxy-u-propionic
methylester.1 is a promising new compound for control of wild oats
and other grass weeds in small grains. Several factors influencing
its use for this purpose were investigated.
Greenhouse bioassay studies were conducted in 1975 to determine
relative persistence of HOE 23408 in four...
Field studies were conducted in 1973 and 1974 to determine the
soil persistence of the herbicide M-3785 (containing 0.5 lb a.e.
Dowco 290 + 2.0 lb a.e. 214D/gallon). under cropping situations.
Spring barley (Hordeum distichon L. 'Hannchen') was grown at
Corvallis, Oregon and winter wheat (Triticum aestivum L. 'Nugaines.')
was...
Investigations were made in the field, greenhouse, growth
chamber, and laboratory to: (a) observe the general activity of N-
(phosphonomethyl)glycine (glyphosate); (b) determine the extent of its
interaction with certain s-triazine herbicides; and (c) find an explanation
for such an interaction.
Greenhouse and growth chamber studies substantiated other
observations that...
Several studies were conducted to determine the effect of weed
density on herbicide efficacy. Diuron [3-(3, 4- dichlorophenyl) -1, 1-
dimethylurea] was tested on various densities of Italian ryegrass
(Lolium multiflorum Lam. ) under greenhouse and field conditions.
Cycloate (S-ethyl N-ethylthiocyclohexanecarbamate) was tested on
green foxtail (Setaria viridis (L. )...
Studies were conducted in 1969 and 1970 to evaluate the
effectiveness of an experimental herbicide, SD 30053 (alanine,
N-benzoyl-N-(3, 4-dichlorophenyl)-, ethyl ester), for wild oat
(Avena fatua L.) control in winter cereals.
The 1969 field studies showed that postemergence applications
of SD 30053 were effective in controlling wild oats. Wild...
Studies were initiated to determine the response of two common
groundsel biotypes (Senecio vulgaris L. ) to several s-triazine herbicides.
Herbicides tested were: 2-chloro-4,6-bis(ethylamino)-striazine
(simazine), 2-chloro-4-(ethylamino)-6-(isopropylamino)-
s-triazine (atrazine) 2-(sec-butylamino)-4-(ethylamino)-6-methoxys-
triazine (GS-14254), 2, 4-bis(isopropylamino)-6-methoxy-striazine
(prometone), 2-(tert-butylamino)-4-(ethylamino)-6-methylthio-
s-triazine (terbutryn), and 2, 4-bis(isopropylamino)-6-
methylthio-s-triazine (prometryne). One biotype was much more
susceptible than the...
Questionnaires were used in a survey of Oregon farmers to determine
how they select and use herbicides on wheat.
Farmer's decisions were evaluated on the basis of their ability to:
select the proper herbicide treatment for their weed problem and to
make application at the proper time.
Questionnaire scores indicated...
Addition of the methylcarbamate compounds p-chlorophenyl
N-methylcarbamate (PPG-124) and 1-naphthyl N-methylcarbamate
(carbaryl) to various herbicides has resulted in reduced rates of
degradation. Carbaryl affects the degradation of certain herbicides
in both plants and soils while PPG-124 has only been demonstrated
to affect degradation in soils. Both these materials are effective...
Experiments were conducted under field and greenhouse conditions
to investigate the effects of chlorpropham (isopropyl mchlorocarbanilate)
on vegetative and reproductive development in
Chewings fescue (Festuca rubra L. subsp. commutata Gaud.) and to
determine the time of induction and initiation under natural conditions.
Chewings fescue was found to be very susceptible...
Oregon is the largest producer of
green beans for processing
in the United States.
Because the repeated use of a single herbicide
may lead to
changes in the weed population, build
up of residues, and other
undesirable factors, a continuous search for
new herbicides is
taking place.
C-6989¹[superscript /] has...
The amounts of residual dichlobenil (2,6-dichlorobenzonitrile)
in water and hydrosoil were compared periodically following application
of the wettable powder and granular formulations of the
herbicide to separate ponds at ten pounds of active ingredient per
surface acre {0.6 ppmw (parts per million by weight) }. Dichlobenil
was measured by electroncapture...
The physical and chemical properties of soils greatly affect the
toxicity of bromacil and picloram. Consequently, a knowledge of the
parameters which influence the soil inactivation of these herbicides
is necessary to determine proper application rates for good weed control.
Enhancement in phytotoxicity with the addition of surfactants or
surface...
Penetration has long been recognized as an important factor
in the action of chemicals on plants. The effectiveness of herbicides
on such plants as blackberries is often thought to be limited by the
failure to obtain adequate penetration through the cuticular barrier.
A number of factors, among them relative humidity,...
Several studies were conducted to determine the feasibility of
using terbacil (3-tert-butyl-5-chloro-6-methyluracil) postemergence
to weeds and peppermint (Mentha piperita L.). Three nonionic surfactants,
four nonphytotoxic oils, and a liquid fertilizer were each
combined with 0.5 lb ai/A terbacil in 35 gallons of water per acre.
Weed species tested include: redroot...
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...
There is a critical lack of economic information in the area of chemical weed control. This paper is intended to stimulate study in this area. The objective is to develop a method of economic analysis of alternative herbicide practices. The data used were taken from a Druchamp winter wheat trial...
This study was conducted to compare the effectiveness of four
methods of incorporating the herbicide trifluralin into the soil, and
to determine the interaction between depth of incorporation of trifluralin
and depth of weed seed germination.
Field experiments on green and dry peas were established in
Oregon and Idaho. Trifluralin,...
The acute toxicity of Diquat (1:1-ethylene-2:2' dipyridylium
dibromide) and Dichlobenil (2, 6-dichlorobenzonitrile) to six selected
pond invertebrates was determined using the median tolerance limit
estimation method. Diquat was more toxic to the amphipod, Hyalella
azeteca than to the aquatic insects Callibaetis, Limnephilus,
Enallagma, Libellula, and Tendipedidae. The addition of mud...
Previous research has indicated several soil-applied herbicides
are more effective by exposure to emerging shoots than from
root uptake. Studies were conducted in the greenhouse and growth
chamber to investigate effects of herbicide placement in soil on
toxicity to emerging seedlings.
In these studies, an inch of treated soil was...
The purpose of this study was to evaluate the activity of Sindone (isomers of 1, 1-dimethyl-diisopropyl-indanyl ethyl ketone) under field conditions and to gain information regarding the rate of detoxification of Sindone in soil. A series of trials were established in sugar beet fields in California, Oregon, and Washington. Sindone...
The effect of Endothal (3, 6-endoxyhexahydrophthalic acid),
sodium pentachlorophenate (Na-PCP) and TD-47 (di-N, N-dimethylcocoamine
salt of Endothal) on the microbial populations, ammonification,
nitrification and respiration in six different soils was investigated.
It was found that Endothal at 20 and 200 ppm had no adverse
effect on the microbial population, ammonification,...
Norbak, Dacagin, and Vistik, when mixed with a spray solution,
each have the unique property of increasing the viscosity of
that solution. This property has been used commercially for the
reduction of spray drift.
Studies were made of the drift control adjuvants to determine
the following: (1) the effect of...
Atrazine is an asymmetrical s-triazine herbicide used pre-
and post emergence for weed control in many crops. Triazine herbicides
have been used in the Pacific-Northwest for weed control in
orchard crops. Under certain conditions where trees were grown
in nutrient deficient areas, it was noted that toxic symptoms due to...
Studies were conducted to determine the site of 2-chloro
2', 6'-diethyl-N-(methoxymethyl) acetanilide (CP 50144) toxicity on
barnyardgrass (Echinocloa crusgalli (L.) (Beauv.). This was done
by means of a technique which used separate layers of treated soil
to expose differentially the roots and/or the shoots of barnyardgrass
seedlings. Coleoptiles that emerged...
The use of CIPC (isopropyl N-(3-chlorophenyl) carbamate) to
control dodder (Cuscuta spp.) in alfalfa is an established practice. A
rate of six pounds per acre applied to moist soil has given good dodder
control lasting from four to six weeks.
The purpose of this study was to determine the effect...
Atrazine is an asymmetrical s-triazine herbicide used pre- and
post-emergence for the control of weeds in many crops. Under conditions
considered unfavorable for microbial activity, atrazine may
persist in soils for extended periods of time. However, the significance
of chemical versus microbial degradation is not known.
This study was conducted...
Studies were conducted to determine the site of DCPA toxicity
on annual ryegrass. This was done by means of a technique which
used pyrex tubing and a vapor barrier to separate exposure of coleoptile
and roots of emerging grass seedlings to various concentrations of DCPA. Coleoptiles that emerged through treated...
Atrazine, atratone and ametryne are asymmetric s-triazine
herbicides used pre- and post-emergence on many crops. Under
conditions unfavorable for microbial activity, these compounds
may persist in the soil for long periods of time.
This study was conducted to determine the influence of the
soil microflora upon atrazine, atratone and ametryne...
The absorption, translocation and metabolism of a new
herbicide, n-propyl-C¹⁴ N, N-di-n-propyl-thiolcarbamate (PDPC), were
studied in both peanut and soybean plants. These studies were
carried out on plants of different ages and treated at two rates of
application. The residue content of the plants was also determined
from germination to...