Behavior and Disappearance of Benthiocarb Herbicide in Water, Soil and Rice Plant of Paddy Fields Treated with Its Granular Formulations

Abstract

Behavior and disappearence of benthiocarb herbicide in water, soil and rice plant of paddy fields treated with its granular formulations were investigated. The formulations were applied to paddy fields at one or two weeks after transplanting rice plant.
The benthiocarb concentration in irrigation water showed about one ppm during two to four days after the application, and then decreased gradually with the elapse of time. The benthiocarb concentration in soil rapidly decreased within one week after the application. The half-life period of benthiocarb in soil was in about three days. The rate of the decrease in soil became slower after the first one week at the application. After one month benthiocarb was detected only in about 10% level of the initial concentration.
Benthiocarb was absorbed rapidly by rice plant and translocated throughout the plant. The benthiocarb concentration in the plant was higher in the top than in the root. The dissipation of benthiocarb was rapid in the former part, compared with the latter.
Remarkable leaching was not observed in the soil of treated paddy fields.