The persistence of DCPA, trifluralin, diphenamid, diuron, and
prometryne was studied in three soils which were located at the Kula,
Poamoho, and Waimanalo Experiment Stations. The order of decreasing
persistency was diuron, prometryne, trifluralin, DCPA, and
diphenamid.
Diuron and prometryne activities were recorded for at least six
months and diuron...
The use of bromoxynil (3,5-dibromo-4-hydroxybenzonitrile)
to control broadleaf weeds in cereal crops has become widespread.
This herbicide has not always performed satisfactorily for reasons
which were not clearly evident.
The effects of temperature, light and humidity on the herbicidal
activity of bromoxynil on coast fiddleneck, Amsinckia intermedia,
were studied. Fiddleneck...
Several studies were conducted to determine if a more consistent
predictor of phytotoxicity to winter oats could be obtained with a
surfactant-herbicide ratio or a per-unit-volume concentration of surfactant,
independent of volume. The herbicides tested were 2,2-dichloropropionic acid (dalapon), 1,1'-dimethyl-4, 4'-bipyridinium
(paraquat), and 3-tert-butyl-5-chloro-6-methyluracil (terbacil) with
the nonionic surfactant X-77...
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 shown that activated carbon is effective
in inactivating certain herbicides applied as a preemergence treatment.
Studies were conducted in the greenhouse to determine the
influence of various factors on the ability of activated carbon to
inactivate herbicides applied after carbon application. Field studies
were conducted to determine...
Lateral diffusion of S-ethyl N-ethylthiocyclohexanecarbamate
(cycloate)¹ is essential for satisfactory weed control with injection
type incorporation in sugar beet (Beta vulgaris Linn.) production.
Previous field experience with injection incorporation has indicated
that sufficient lateral diffusion for satisfactory weed control has not
occurred under all field conditions. Researchers who have been...
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...
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...
Previous research has shown that specific carotenoid pigments
function through oxidation-reduction reactions to protect chlorophyll
from photooxidation in the presence of reduced nicotinamide adenine
dinucleotide phosphate (NADP). The hypothesis that diuron (3-(3, 4-
d chloropheny1)-1, 1-dimethylurea) initiates phytotoxicity by inhibition
of NADPH synthesis was examined. All experiments were conducted
in...