六种杀虫剂在保护地黄瓜冠层的沉积分布及其对蚜虫防治效果的影响

为明确不同药剂在保护地黄瓜上的沉积分布及其对蚜虫防治效果的影响,利用农药雾滴采集装置收集农药雾滴,以诱惑红为示踪剂测定农药沉积量,通过DepositScan软件测定雾滴覆盖率,分析药剂在黄瓜冠层的沉积分布与其对蚜虫防效的关系。结果表明:阿维菌素、螺虫乙酯、吡虫啉、吡丙醚、噻虫嗪和啶虫脒6种药剂的沉积量与雾滴覆盖率之间均无显著差异,分布趋势均表现为顶部>中部>底部;药后1 d和3 d,不同药剂对同一冠层部位以及同一药剂对不同冠层部位黄瓜蚜虫的校正防效之间均无显著差异,且防效均达65%以上。背负式手动喷雾器按田间推荐剂量喷雾防治黄瓜蚜虫时,喷雾雾滴主要沉积在黄瓜冠层顶部,沉积量占到总沉积量的1/3以上,在冠层中部和底部的沉积量相对较少,但沉积到冠层中部和底部的农药剂量仍能发挥良好的防治效果。该研究结果可为合理使用农药防治黄瓜蚜虫提供科学依据。

Deposition and distribution of six insecticides in greenhouse cucumber canopies and the impact on the control efficacy to Aphis gossypii

In this work, the droplet deposition and distribution of different insecticides in cucumber canopies and the impact on the control efficacy against Aphis gossypii were investigated. The droplet coverage of six insecticides was determined by DepositScan software. The insecticide droplets were collected by the relevant collection devices and spray droplet test cards. Meanwhile, the insecticide deposition was determined by the Allura red tracer. Then the relationship between the droplet deposition distribution in the cucumber canopy and the control efficiency against A. gossypii was illustrated. The results showed that the droplet deposition and coverage of abamectin, spirotetramat, pyriproxyfen, thiamethoxam, imidacloprid and acetamiprid on cucumber plants had no significant difference. The droplet deposition and coverage of the six insecticides was manifested with the distribution trend of top > middle > bottom. On the 1st and 3rd day after spraying, the corrected control efficacy of the six insecticides against A. gossypii on the same canopy position or the same insecticide to A. gossypii on different canopy positions were all above 65% and no significant different was detected among treatments. The droplets from knapsack manual sprayer mainly deposited on the top canopy of the cucumber. The droplet deposition on the top canopy accounted for above 1/3 of the total deposition amount, while the deposition was relatively lower on the middle and bottom canopies. However, the insecticide deposited in the middle and bottom canopies could still provide good control efficacy against A. gossypii when applied with the recommended dosage in the field. The results have provided a scientific basis for the rational control of A. gossypii.