5％醚菊酯展膜油剂配制及其对稻飞虱的防治效果

Preparation of 5% ethofenprox spreading oil and it′s control efficacy on rice planthopper

采用正交试验设计,通过对溶剂及表面活性剂的筛选和配伍,确定了5%醚菊酯展膜油剂的最优配方(各组份的量用质量分数表示)为:醚菊酯5.0%;溶剂月桂酸甲酯50.0%;OP-4、OP-10、2201和十二碳醇酯以质量比4∶4∶3∶9复配,总质量分数为10.0%;大豆油35.0%。所配制的5.0%醚菊酯展膜油剂外观透明,经热贮(54℃±2℃)14d后无沉淀、结晶和分层现象,热分解率为0.10%;35℃时的表面张力为28.33mN/m,滴施在水面时的油/水界面张力为0.11mN/m;能够在水面快速铺展,滴加量1.28μL时,铺展速度为9.29cm/s,铺展面积达到1 882.74cm2。使用时无需喷雾,只需将药剂瓶置于水田上方,药剂即从滴出孔自行滴下,迅速铺展于水田表面。田间施药7d对稻飞虱的校正防效达到78.5%。

5% ethofenprox spreading oil （SO） was developed by orthogonal experiment through the screening of the solvent and surfactant. The optimum solvent was 50.0% methyl laurate. The proportion of the mixture of surfactant, OP-4, OP-10, 2201 and dodecanol ester, was 4： 4： 3：9 （m/m）, which was 10.0% weight in total of the formulation. The other component was soybean oil, which was 35.0% of the formulation. The formulation had been stored at （54℃±2℃） for 14-days without precipitation, crystallization and layer-separation. The decomposition rate was 0.10%. Surface tension was 28.33 mN/m and interfacial tension was 0.11 mN/m at 35 ℃. Spreading speed and area reached 9.29 cm/s and 1 882.74 cm^2 with 1.28 μL. This formulation could be directly dropped to paddy water without any dilution. The active ingredient dropped on paddy water surface and spreaded to whole water surface of the paddy field in a few minutes. The field application showed that after 7 d the corrected control efficacy of 5% ethofenprox SO against rice planthoppers was 78.52%.