Abstract:

For the evaluation of ecological security of emamectin benzoate after use in cabbage and soil, and guiding emamectin benzoate the scientific and rational use, field experiment was conducted to reveal residual degradation dynamics and the final residues of emamectin benzoate in cabbage and soil, the residues of emamectin benzoate in cabbage and soil were determined by HPLC with FLD, and application safety was assessed. The degradation dynamic test results showed that the half-live of emamectin benzoate in soil was 10.2-12.6 d, more than 80% degradation at 28th day after application, and the half-live of emamectin benzoate in cabbage was 1.9-2.3 d, more than 90% degradation at 7th day after application. The final residue tests showed that emamectin benzoate was sprayed for 2 to 3 successive times at application dose 3.3 g a.i./hm2, 4.95 g a.i./hm2, at 7th, 14th, 21th after the last application, the final residues of emamectin benzoate in cabbage were all lower than the minimum detection limit. Therefore, preharvest interval was suggested to be 7 days when emamectin benzoate was applied at recommended dosage for cabbage.