Persistence of Acetamiprid in Selected Soils of Karnataka

Persistence and degradation of acetamipirid was determined in soils of three different locations of Karnataka viz., Kodagu, Bangalore and Chamarajanagar. The soils were incubated at 25 mg kg^-1 of acetamiprid using soluble powder formulation grade acetamiprid (Star-20) under different moisture regimes air dry, field capacity, submergence and alternate wetting-drying. The persistence of acetamiprid differed in all the three soils. Higher persistence was noticed in Chamarajanagar soil followed by Kodagu and Bangalore soils. Half-life (t_1/2) of acetamiprid was found to be was highest in air dry moisture regime in Chamarajanagar soil (97.6 days) compared to Kodagu soil (96.8 days) and Bangalore soil (95.2 days). The half-life values in field capacity, submergence and alternate wetting-drying are 56.7, 64.5 and 61.8 days (Kodagu), 59.4, 66.7 and 57.7 (Bangalore) and 59.1, 66.7 and 70.8 days (Chamarajanagar) soils, respectively. The degradable pattern of acetamiprid residue followed a close correspondence to first order exponential degradation in all the three soils.