毒死蜱·高效氯氰菊酯的微胶囊化及其对蛴螬的防治效果

用原位聚合法制备了毒死蜱·高效氯氰菊酯复配微囊悬浮剂(CS),研究了表面活性剂对微胶囊化过程的影响,并考察了产品对蛴螬Anomala corpulenta Motsch的田间防治效果。结果表明,SUR-1(植物皂素和明胶等比例组合物)是较为理想的成囊助剂,当其质量分数为0.2%时两种农药的包覆率可达98%以上,囊形均匀、圆滑,囊径和囊壁厚度适中,但其用量不宜过高,当其质量分数为0.4%时,毒死蜱和高效氯氰菊酯的包覆率分别仅有74.2%和68.1%,同时,释放速率也显著下降。20%毒死蜱·高效氯氰菊酯CS在有效成分含量(下同) 600 g/hm2用量下,对蛴螬60 d的防效可达70%以上,而毒死蜱和高效氯氰菊酯乳油在土壤中的降解较为迅速,当施药剂量分别为1 440和33.75 g/hm2时,60 d的防效分别仅为32.3%和2.5%。

Microcapsulating and Control Efficacy of Chlorpyrifos*Beta-cypermethrin on Grubs(Anomala corpulenta)

The preparation of chlorpyrifs·beta-cypermethrin capsules suspension(CS) by in-situ polymerization was introduced,the influence of the surfactant on microcapsulating process and the control efficacy of this product on the grubs(Anomala corpulenta Motsch)were investigated. The results indicated that SUR-1(the equal ratio mixture of saponin and gelatin) was the best surfactant to prepare chlorpyrifos·beta-cypermethrin capsules suspension. When the mass percent concentration of SUR-1 was 0.2%,the uniform microencapsules with satisfied diameter and wall thickness were obtained,and the encapsulating rates of two pesticides were above 98%,however,when the mass percent concentration of SUR-1 was increased to 0.4%,the encapsulating rates of chlorpyrifos and beta-cypermethrin decreased to 74.2% and 68.1%,respectively,and the release rates of two pesticides also decreased obviously. The field trials showed when the treated dose was 600 g(a.i. )/hm² that the control efficacy of the 20% chlorpyrifos·beta - cypermethrin CS on the grubs was still above 70% 60 days after treatment.Meanwhile,chlorpyrifos EC and beta-cypermethrin EC were degraded rapidly in the soil,when the treated doses of the two products were 1 440 and 33.75 g(a.i. )/hm², respectively.The control efficacy on the grubs were only 32.3% and 2.5% 60 d after treatment.