No abstract

Studies on the dissipation ofphorate in different types of soils of Kerala, India, were carried out. The residues of the insecticide persisted most in the forest soil followed by alluvial, red, laterite and sandy soils in the descending order. The half-life periods of the insecticide estimated by chemical and bioassay methods approximated to one another. Correlations of the persistence of the insecticide with the properties of the soil revealed that organic matter played a dominant role in prolonging the persistence of the insecticide in the soils.