BIOACTIVITY OF FENSULFOTHION AND TRICHLORONAT IN SOIL

Abstract

AbstractWhen trichloronat or fensulfothion was applied to the soil surface, the toxicity of both compounds to first stage root maggot larvae increased during the first few days, then decreased at a constant and relatively rapid rate. When trichloronat was mixed with the top 1 in. of soil, its toxicity or that of its metabolites increased for about 3 months, then gradually decreased. When it was applied in a band below the surface, its persistence increased with the depth of application. When fensulfothion was applied in the same manner, its toxicity was not greatly influenced by the method of application; this decreased during the first 4 or 5 days, rose to a peak in 15 to 30 days, then gradually decreased. Fensulfothion was highly systemic in rutabagas. Its toxicants were most bioactive 60 to 80 days after application and decreased gradually thereafter. Trichloronat toxicants were slowly absorbed by the roots but toxic residues did not degrade in storage.