The environmental fate of different forms of ZJ0702 in open rape field and MRL calculation

In the present work, the environmental fate, including residual level and dissipation rate of two formulations of ZJ0702 (a new pyrimidine salicylic herbicide which showed good inhibitory effect on the weeds in rape fields), EC and SC, were determined by high performance liquid chromatography with DAD. The herbicide was used in Hangzhou and Kunming in rape fields at the same time for 2 years. The results were that half-lives of ZJ0702 in rape ranged from 1.2-6.8 days, while in soil samples were from 15.2-47.1 days. On the sampling days, the final residues of ZJ0702 in rapeseed were below the limit of quantitation (0.02 mg/kg). The differences of dissipation rate suggest that local soil characteristics and climate, and the formulations would affect the decline of ZJ0702. The low final residue levels of ZJ0702 in rapeseed and soil indicated that this new pesticide was environmentally safe. It was recommended that MRL for ZJ0702 in rapeseed be 1 mg/kg in China.