In intensively managed forest plantations in the northern Oregon Coast Range, herbicides are often applied during site preparation and early stand regeneration to reduce competition for resources for planted conifer seedlings. In addition to reducing competition for crop trees, herbicide applications may affect soil processes including decomposition and nutrient cycling,...
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...
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...
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,...
Detoxification of atrazine in soils results from both chemical
hydrolysis and microbial degradation.
Infrared analysis was used
to study the hydrolysis of atrazine upon interaction with soil
colloids
and to ascertain the existence of enol, keto, and protonated-keto
forms of hydroxyatrazine.
Evolution of ¹⁴CO₂ from ¹⁴C-atrazine
and ¹⁴C-hydroxyatrazine was indicative...
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...
Glyphosate (N-(phosphonomethyl)glycine) is an effective
foliar-applied herbicide with broad-spectrum activity. Greenhouse
and laboratory experiments were conducted to determine the
importance of soil moisture, autoclaved soil, soil type, sphagnum
peat, soil pH, added phosphorus, and plant residues on crop
establishment and growth when glyphosate was applied before
emergence of the crop....
Previous studies have shown loss of ethofumesate activity when
the herbicide was applied to dry soil (2% w/w moisture content) in
both field and greenhouse studies, even when rainfall or irrigation
was received within a few days. Laboratory studies were conducted to
determine the mechanism for this activity loss. Dry...