Residual dynamics and residual limits of triflumizole in ginseng and soil

【Objective】 The research aims to achieve the reasonable application of triflumizole in Panax ginseng. 【Method】 Field trial and gas chromatography mass spectrometry were carried out to study residual decline and final residues of triflumizole 30% WP after being sprayed in 0,7,14,21,28,74 days.【Result and conclusion】 The results showed that the original deposition of triflumizole was 0.54 and 0.25 mg·kg^-1 respectively in ginseng and soil；the half-life of triflumizole was 19.9 and 25.4 d respectively in ginseng and soil. The final residue was 0.04 mg·kg^-1 and 0.14 mg·kg^-1 respectively in fresh root and dry root, while the sprayed dosage was 1 000 g·hm^-2. Based on many factors, the maximum residual limit （MRL） of triflumizole is suggested to be 0.05 mg·kg^-1 and 0.2 mg·kg^-1 in the fresh root and dry root respectively. Application of triflumizole should be just once in every growing season, and the practical dosage should not be over 1 000 g·hm^-2. The preharvest interval can not be determined.