Dissipation of Aldicarb Residues in Soil and Green Gram and Cowpea Crops*

Persistence of aldicarb in soil as well as in green gram and cowpea crops was studied during kharif 1983, 1984 and summer 1984, when applied at the rate of 1.0 and 1.5 kg a.i./ha at the time of sowing. Initial deposit of aldicarb in soil ranged from 8.5 to 15.3 ppm which persisted for more than 45 days. Dissipation followed a first order reaction and was faster during kharif than in summer. The residues of aldicarb trans-located into plant parts degraded below tolerance level at 45 days at lower dose, while at higher dose, residues were above Maximum Residue Limit. The residues were non-detectable in green pods at first picking and thus could be consumed safely at harvest.