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...
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...
EPIC (S-ethyl dipropylthiocarbamate) is a selective herbicide
which controls some annual grasses, annual broadleaves, and perennial
grasses when incorporated into the soil before planting. In the last
few years, reports have been received of certain fields in the
Willamette Valley of Oregon in which EPIC was no longer effective.
Preliminary...
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...
Growth of individual goosegrass (Eleusine indica (L) Gaertn.) plants of
three dinitroaniline-herbicide resistant (R) and three susceptible (S) biotypes from
North Carolina, South Carolina, and Mississippi was analyzed in greenhouse
experiments. Leaf area and biomass measurements, including root, shoot,
above-ground, and total dry weights were similar among the biotypes studied....
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...
Studies were conducted to verify the existence of IAA in wheat
seedlings and to determine the effect of (2-chloroethyl)-trimethyl-ammonium
chloride (CCC) on the IAA content of club wheat,
Triticum aestivum compactum, variety Omar. The shoots of CCC-treated
and untreated wheat plants were extracted with ethanol, the
plant extract purified, separated...
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. )...
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...