利用假茎注射吡虫啉防控香蕉蓟马

本研究使用专用注射器在香蕉花蕾刚现出时,通过假茎注射吡虫啉防治蓟马。试验1为70%吡虫啉水分散粒剂稀释200、250、300倍液,每株注射40mL;试验2为70%吡虫啉水分散粒剂稀释200倍液,每株注射20、40、60mL。结果表明:试验1和试验2的各处理对香蕉植株均没有药害。试验1中,70%吡虫啉水分散粒剂稀释200倍液对蓟马的防效为82.4%,与常规处理差异不显著,而稀释250、300倍液的防效为75.5%、66.8%,显著低于常规处理。试验2中,70%吡虫啉水分散粒剂200倍液3个注射剂量处理对蓟马的防效分别为77.9%、86.3%、89.6%,注射20mL的防效显著低于注射40mL和60mL的处理。在生产中,利用香蕉假茎注射施用70%吡虫啉水分散粒剂防治蓟马,考虑防效及成本,推荐浓度为稀释200倍液,每株注射40mL。该施药方法节省了农药使用量、施药时间,操作简便,达到了农药减量与确保防效并举的效果,为香蕉生产中减量使用农药提供了技术依据。

Control of thrips by injecting imidacloprid into banana pseudostem

The banana thrips Thrips hawaiiensis (Morgan) is a very serious pest in banana plantations. Spraying insecticide to whole plant was the main practice for controlling thrips. However, the disadvantages were the toxicity to beneficial insects due to insecticide application and its high proportion of non-target effect. Therefore, the control efficacy against thrips was investigated by injecting imidacloprid into banana pseudostem. The results showed that injecting imidacloprid into banana pseudostem was safe to banana plants when 70% imidacloprid WG was diluted by 200, 250, 300 times, because no damage symptom was observed in those plants. The control efficacy of 200 times dilution reached 82.4%, significantly higher than that of 250 or 300 times dilution. The control efficacy of 200 times dilution was comparable to conventional treatment. The control efficacy against thrips was 86.3%, 89.6%, respectively, at the dosage of 40 mL, 60 mL when 200 times dilution of 70% imidacloprid WG was applied, which was much higher than that at the dosage of 20 mL.In conclusion, it was an effective way to control thrips by injecting imidacloprid into banana pseudostem with 200 times dilution at the dosage of 40 mL.This comprehensive management will reduce the usage of insecticide and times for application. It will also provide a practical strategy for sustainable agricultural production in banana plantation