印楝素与吡虫啉对牛蒡长管蚜毒力最佳配比的筛选及田间防效研究

［目的]探索印楝素与吡虫啉混配防治牛蒡长管蚜的最佳配比及其防效。［方法］采用叶片浸渍法研究印楝素与吡虫啉混配对牛蒡长管蚜的增效作用及两种药剂混配的最佳配比。［结果］室内毒力测定结果表明，印楝素与吡虫啉混用防治牛蒡长管蚜具有明显的增效作用。在印楝素与吡虫啉按有效成分104∶1比例进行混配，增效作用明显，共毒系数达142.179 3。田间试验结果表明，10％吡虫啉WP 2 000倍防治牛蒡长管蚜显示出高效、快速的特点，药后1 d防治效果就超过了91%，药后7 d超过94%。0.32%印楝素EC 500倍防治效果比较低，药后7 d才达到75.13%，但与吡虫啉按有效成分104∶1比例进行混配后的600、800倍液药后7 d的防治效果超过了93%。［结论］ 该研究为牛蒡长管蚜无公害综合治理技术的制定提供了依据。

Study on the Screening of Optimum Toxicity Ratio of Azadirachtin and Imidacloprid against Uroleucon gobonis(Matsumura) and Their Field Control Effects

[Objective] The aim was to explore the optimum ratio and control effect of azadirachtin and imidacloprid against Uroleucon gobonis.[Method] The synergism of mixed ligand of azadirachtin and imidacloprid against U.gobonis and their optimum ratio were studied by leaf immersion.[Result] The toxicity indoor result showed that the synergism of mixed ligand of azadirachtin and imidacloprid against U.gobonis was obvious.When the ratio of azadirachtin and imidacloprid was 104∶1 according to effective components,the synergism of the mixed ligand was more obvious,and then the co-toxicity coefficient reached 142.179 3.Field test result showed that 10% imidacloprid WP diluted 2 000 times had efficient and fast effect on U.gobonis,and its control effect exceeded 91% in 1 d and that exceeded 94% in 7d.The control effect of 0.32% azadirachtin EC diluted 500 times was lower and its control effect reached 75.13% in 7 d,but when it was mixed with imidacloprid according to 104∶1 of effective component,the control effect of mixed ligand diluted 600 and 800 times exceeded 97% in 7 d.[Conclusion] The research provided basis for establishment of harmless integrated management technology for U.gobonis.