Drift and Volatilization of Some Pesticides Sprayed on Chinese Cabbages

In order to investigate the drift of pesticides sprayed on Chinese cabbage, 7 pesticides chlorpyrifos, EPN, pirimiphos-methyl, phenthoate, tetradifon, dicofol and bifenthrin were applied in two sets of field tests. The pesticide residues were quantified bar multiple-residue analysis, in which the recovery rate was 7892% and standard deviation was . It was found that most of the tested pesticides were spread by drift to neighbouring area and brought about the contamination of the unsprayed crops. The extent of drift varied depending upon the pesticide, distance and wind direction. The mean residue levels on unsprayed crops were 0.66% at 3 meter distance, 0.10% at 6 m distance and 0.05% at 9 m distance from the applied area and the maximum level was 1.83% of the residue on sprayed crops.