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....
Field studies were started at Hyslop Farm, Corvallis,
Oregon in 1984 to determine the soil persistence of the
herbicide clopyralid (3,6-dichloropicolinic acid) under
cropping situations. The herbicide was sprayed on bare soil
at the proposed use rate of 0.14 kg/ha in the spring and on
the same plots at a...
The behavior of metribuzin [4-amino-6-(1,1-
dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] and
ethyl-metribuzin (4-amino-6-(1,1-dimethylethyl)-3-
(ethylthio)-1,2,4-triazin-5(4H)-one] in soil was studied to
determine if differences in herbicide behavior in soil could
explain (a) the inconsistent herbicidal activity of these
chemicals and (b) the greater activity of metribuzin, as
compared to ethyl-metribuzin.
Metribuzin had higher activity than ethyl-metribuzin...
Sandy soils are among the least productive soils because of their inability to
store adequate water for plant growth. Their high percolation rate not only allows
water to move quickly beyond the root zone, but also washes nutrients below the reach
of plant roots. High evaporation occurs from the soil...
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...
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...