三氟苯嘧啶·溴氰虫酰胺对水稻稻飞虱及螟虫的田间防治效果评价

2015-2016年,采用田间小区试验评价了23%三氟苯嘧啶·溴氰虫酰胺SC、10%三氟苯嘧啶SC、10%溴氰虫酰胺SC与50%吡蚜酮WG对稻飞虱、二化螟和稻纵卷叶螟等水稻害虫的防治效果。结果表明,23%三氟苯嘧啶·溴氰虫酰胺SC能有效控制稻飞虱、二化螟和稻纵卷叶螟为害;药后3～30 d对稻飞虱的防治效果为75.12%～100.00%,药后15～30 d对二化螟和稻纵卷叶螟的防治效果分别为82.09%～99.12%和78.34%～95.71%。10%三氟苯嘧啶SC、50%吡蚜酮WG对稻飞虱高效,但对二化螟和稻纵卷叶螟效果很差;药后3～30 d对稻飞虱的防治效果分别为81.94%～97.76%和74.91%～93.56%,药后15～30 d对二化螟的防治效果分别为18.23%～43.14%和35.34%～42.71%、对稻纵卷叶螟的防治效果分别为20.04%～48.06%和13.62%～34.78%。10%溴氰虫酰胺SC对稻飞虱有一定效果却难以控制其危害,但对二化螟和稻纵卷叶螟高效;药后3～30 d对稻飞虱的防治效果为33.28%～62.11%,药后15～30 d对二化螟和稻纵卷叶螟的防治效果分别为90.51%～96.60%和86.51%～95.26%。综上,建议在对稻飞虱、二化螟和稻纵卷叶螟发生做好监测预报的基础上,采用如下措施:若只有稻飞虱发生达到防治指标而二化螟和稻纵卷叶螟轻发生,只需使用10%三氟苯嘧啶悬浮剂25 g/hm^2即可;若稻飞虱发生较轻未达到防治指标,而二化螟和稻纵卷叶螟达到防治指标,则只需使用10%溴氰虫酰胺悬浮剂45 g/hm^2即可;当稻飞虱、二化螟和稻纵卷叶螟均达到防治指标时,建议于稻飞虱低龄若虫盛发期或二化螟及稻纵卷叶螟低龄幼虫盛发期施用1次23%三氟苯嘧啶·溴氰虫酰胺SC 34.5 g/hm^2,对水450～750 L/hm^2茎叶均匀喷雾。

Evaluation of control efficacy of triflumezopyrim plus cyantraniliproleagainst rice planthoppers and stem borers under field conditions

Field plot experiments were conducted to evaluate control efficacy of triflumezopyrim·cyantraniliprole 23% SC, triflumezopyrim 10% SC, cyantraniliprole 10% SC and pymetrozine 50% WG against rice planthoppers, the striped stem borer, Chilo suppressalis and rice leaf roller, Cnaphalocrocis medinalis in 2015-2016. The results showed that triflumezopyrim·cyantraniliprole 23% SC could effectively control the above pests. The control efficacies against rice planthoppers were 75.12%-100.00% 3-30 days after treatment and those against C. suppressalis and C. medinalis were 82.09%-99.12% and 78.34%-95.71%, respectively, 15-30 days after treatment. Rice planthoppers was obviously controlled by triflumezopyrim 10% SC or pymetrozine 50% WG, but C. medinalis and C. suppressalis could not be controlled. The control efficacies of the above two insecticides against rice planthoppers were 81.94%-97.76% and 74.91%-93.56%, respectively, 3-30 days after treatment, and those against C. suppressalis and C. medinalis were 18.23%-43.14% and 35.34%-42.71%, 20.04% -48.06% and 13.62%-34.78%, respectively, 15-30 days after treatment. However, C. medinalis and C. suppressalis were obviously controlled by cyantraniliprole 10% SC, but rice planthoppers was difficult to control. The control efficacies of cyantraniliprole 10% SC against rice planthoppers were 33.28%-62.11% 3-30 days after treatment, and those against C. suppressalis and C. medinalis were 90.51%-96.60% and 86.51%-95.26%, respectively, 15-30 days after treatment. These results suggested that the corresponding strategies should be adopted based on the occurrence monitoring and forecasting of rice planthoppers, C. suppressalis and C. medinalis. Triflumezopyrim 10% SC at dosage of 25 g/hm2 was applied only if control indexes of rice planthoppers were achieved, but C. suppressalis and C. medinalis were slightly infested.Cyantraniliprole 10% SC at dosage of 45 g/hm2 was sprayed only if control indexes of C. suppressalis and C. medinalis were achieved, but rice planthoppers were slightly infested. In addition, if control indexes of rice planthoppers, C. suppressalis and C. medinalis were achieved, one time application of triflumezopyrim·cyantraniliprole 23% SC at dosage of 34.5 g/hm2 by foliar spray with usage volume of water at 450-750 L/hm2 could be recommended during a peak period of young nymph of rice planthoppers or of young larvae of C. suppressalis and C. medinalis.