金龟子绿僵菌与化学农药减量联用对棉花苗蚜的防控效果

Control of Cotton Seedling Aphids Using Metarhizium anisopliae Combined with Reduced-Dosages Chemical Pesticides

为减少棉花苗蚜防治中化学农药使用量,本文开展了金龟子绿僵菌CQMa421可分散油悬浮剂与化学农药减量联用对田间棉花苗蚜的防控效果研究。结果表明,金龟子绿僵菌CQMa421可分散油悬浮剂推荐剂量(900 mL/hm^(2))单独施用对苗蚜田间防效为5.36%~15.46%,整体防效较低;3种化学农药对苗蚜防效较好,其中,50 g/L双丙环虫酯可分散液剂速效性和持效性均最高,50%氟啶虫胺腈水分散粒剂和10%氟啶虫酰胺水分散粒剂药后3 d防效较为稳定。化学农药推荐用量和金龟子绿僵菌联合施用可提高药剂防蚜效果,减量25%和金龟子绿僵菌联合施用与化学农药推荐用量单独施用防效无显著差异,其中,10%氟啶虫酰胺水分散粒剂和金龟子绿僵菌减量联用效果较好,减量25%和金龟子绿僵菌联合施药后1 d、3 d、7 d和14d防效比氟啶虫酰胺推荐用量单独施用分别增加34.76%、7.02%、3.25%和5.49%。供试药剂及减量联用处理可降低苗蚜为害造成的有蚜株率和卷叶株率,50 g/L双丙环虫酯可分散液剂各处理卷叶株率显著低于其他处理,推荐用量、推荐用量与金龟子绿僵菌联用、减量25%与金龟子绿僵菌联用、减量50%与金龟子绿僵菌联用卷叶株率分别为5.47%、5.51%、4.82%、12.78%。综合来看,金龟子绿僵菌CQMa421可分散油悬浮剂单独施用对苗蚜防效有待提高,与部分化学农药减量25%~50%联合施用具有协同增效作用。

To reduce the use of chemical pesticides for control of seedling aphids,combination of Metarhizium anisopliae CQMa421 OD with reduced-dosages of chemical pesticides were evaluated in field trials.The results showed that the recommended dosage of the M.anisopliae CQMa421 OD(900 mL/hm^(2))alone achieved a control of 5.36%—15.46%and the three chemical pesticides had good control of seedling aphids.Especially,afidopyropen DC 50 g/L achieved the best field efficacy,with quick action and long persistence;the control effects of sulfoxaflor 50%WG and flonicamid 10%WG were relatively stable at 3 days after application.The combined application of 25%dosage of chemicals with M.anisopliae showed control equivalent to chemical pesticides alone.Among them,the control of the combined application of flonicamid 10%WG with M.anisopliae was the highest,being 34.76%,7.02%,3.25%and 5.49%higher at 1,3,7,14 days after combined application than the control with the recommended dosage of flonicamid 10%WG alone,respectively.The rates of plants with aphids and leaf rolling could be reduced by the use of the chemical pesticides and Metarhizium anisopliae,5.47%,5.51%,4.82%,and 12.78%of leaf-rolling plants were observed with the recommended dosage,the combined use of M.anisopliae with the recommended dosage,the 25%dosage,and the 50%dosage of afidopyropen 50g/L DC,respectively.To sum up,the control effect of M.anisopliae CQMa421 OD used alone is low and needs to be improved,the combined application of M.anisopliae with 25%or 50%dosage of some chemical pesticides has significant synergistic effects.