溴氰菊酯在油麦菜和土壤中的残留动态及安全使用评价

Residual Dynamics and Safety Evaluation of Deltamethrin in Leaf Lettuce and Soil

通过田间试验和室内检测,研究了溴氰菊酯在油麦菜及土壤中的残留动态及最终残留。结果表明：溴氰菊酯在油麦菜中的半衰期为2.6~2.9 d,药后14 d消解96%以上。溴氰菊酯在土壤中的半衰期为7.5~8.2 d,药后14 d消解73%以上。25 g/L溴氰菊酯乳油18.75、28.125 g a.i./hm2,施药3~4次,末次施药后5 d收获的油麦菜中溴氰菊酯残留量均低于0.5 mg/kg。推荐该药在油麦菜上的安全间隔期为5 d。

In order to explore the residual properties and safety of deltamethrin in leaf lettuce,the field experiment and laboratory test were conducted to reveal the residual degradation dynamics and final residues of deltamethrin in leaf lettuce and soil. The results showed that the half-life of deltamethrin in leaf lettuce and soil was 2. 6 ~ 2. 9 d and 7. 5 ~ 8. 2 d respectively,and the residue degradation rate in leaf lettuce and soil after application for 14 days was above 96% and 73% respectively. When the leaf lettuce was sprayed 3 ~ 4times with 25 g / L deltamethrin EC of 18. 75 g a. i. / hm2 and 28. 125 g a. i. / hm2,the residual quantity in harvested leaf lettuce was lower than 0. 5 mg / kg after the last application for 5 days. It was demonstrated that the preharvest interval of deltamethrin on leaf lettuce was 5 days.