为了评价“溴氰菊酯”在香料烟中的残留降解行为,进行了连续2年“溴氰菊酯”在香料烟中的残留田间试验.检测结果表明:①2.5％“溴氰菊酯”乳油在香料烟叶中的降解符合一级动力学降解模式,其半衰期为5.80 ～ 6.19 d；②施药后15 d残留量在0.0128 mg· kg-1以下,降解率达95％以上；③按600 mL· hm-2喷施2次和3次2.5％“溴氰菊酯”乳油,15 d后采收,香料烟鲜烟叶中的残留量为＜0.01～ 0.4703 mg· kg -1；④2年的气候条件虽然有差异,但“溴氰菊酯”在香料烟中的残留降解行为基本一致.在香料烟的生长过程中,按照推荐用量,在15 d安全间隔期以上,连续3次施用2.5％“溴氰菊酯”乳油,“溴氰菊酯”的残留量不超过0.05 mg· kg-1.%In order to assess the degradation behavior of deltamethrin residues in oriental tobacco, the field experiments were conducted for two consecutive years with 2.5% deltamethrin EC. The test results indicated that: 1) The degradation of deltamethrin EC in oriental tobacco accorded with first level dynamics degradation model, its half-life period was of 5.80 to 6.19 days. 2) The residues of deltamethrin in oriental tobacco were below 0.0128 mg/kg 15 days after spraying, and the degradation rate was higher than 95%. 3) The residues of deltamethrin in green leaf harvested on 15th day after spraying deltamethrin at a rate of 600 mL/ha (the recommended rate) for 2 or 3 times ranged from < 0.01 to 0.4703 mg/kg. 4) The degradation behavior was basically unchanged, though the climate conditions were different in the two years. Tt was concluded that the residues of deltamethrin in oriental tobacco would be below 0.05 mg/kg if it was repeated applied for 3 times at the recommended rate and at an interval of over 15 days.
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