25%乙基多杀菌素水分散粒剂对玉米草地贪夜蛾田间防治效果

Field Efficacy Evaluation of Spinetoram 25%WG Control Spodoptera frugiperda in Maize

为进一步探明乙基多杀菌素对玉米安全性及对草地贪夜蛾的防效、持效期与用法用量,筛选出防控玉米草地贪夜蛾的高效、低毒、环境友好的药剂。选用25%乙基多杀菌素水分散粒剂开展田间小区药效试验。结果表明,乙基多杀菌素水分散粒剂对玉米安全、对草地贪夜蛾具有较好的防治效果,随着用量的增加,防效和持效期增加,较为突出的是乙基多杀菌素180、240 g/hm^(2)处理,药后1~3 d对草地贪夜蛾防效均为100.00%,药后7~14 d防效均在75.00%以上,且在药后14 d保苗效果仍在65.00%以上,玉米受害等级控制在2级以下,玉米受损程度偏轻,药效持续期达14 d。此外,20%多杀霉素悬浮剂在试验中也表现出较好的防效,药后1~3 d对草地贪夜蛾防效在90.00%以上,药后7~14 d防效均在75.00%以上。在实际生产中推荐选用25%乙基多杀菌素水分散粒剂180 g/hm^(2)用量、20%多杀霉素悬浮剂225 mL/hm^(2)用量防治玉米草地贪夜蛾。

In order to further explore the safety of spinetoram in maize,the control effect,duration,usage and dosage on Spodoptera frugiperda,screened out effective,low toxicity and environmentally friendly agents for controlling Spodoptera frugiperda.Spinetoram^(2)5%WG was used to carry out the field plot efficacy test.The results showed that spinetoram^(2)5%WG was safe for maize and had a good control effect on Spodoptera frugiperda.With the increase of the dosage,the control effect and duration increased.The more obvious one was that spinetoram^(2)5%WG was 180-240 g/hm^(2),and the control effect on Spodoptera frugiperda was 100.00%after 1-3 days of treatment,the control effect was above 75.00%after 7-14 days,and the seedling protection effect was still above 65.00%after 14 days.The damage grade of maize was controlled below grade 2,the damage degree of maize was mild,and the duration of efficacy was 14 days.In addition,spinosyn 20%SC also showed good control effect in the test,the control effect was above 90.00%after 1-3 days of treatment,and the control effect was above 75.00%after 7-14 days of treatment.It is recommended to use spinetoram^(2)5%WG 180 g/hm^(2)or spinosyn 20%SC 225 mL/hm^(2)to control Spodoptera frugiperda of maize.