50%噻虫嗪悬浮种衣剂的研制及其对棉花蚜虫的防治效果

为研制高含量的噻虫嗪悬浮种衣剂,提高其对棉花蚜虫的防治效果,分别采用流点法及因素轮选法等对润湿剂、分散剂、成膜剂和增稠剂等助剂进行筛选及优化,最终采用湿法砂磨超微粉碎法研制了50%噻虫嗪悬浮种衣剂,对其性能指标进行了测试,并测定了其对棉花种子发芽势和发芽率的影响以及对棉花蚜虫的田间防治效果。结果表明:以质量分数为50%的噻虫嗪为有效成分、3%的FD及1%的BC-10为润湿剂、2.5%的SP-2836及2.5%的SK-24为分散剂、1%的硅酸铝镁及0.05%的黄原胶为增稠剂和2.5%的BF308为成膜剂而研制的50%噻虫嗪悬浮种衣剂性状良好,悬浮率高,热贮稳定性好,对棉花种子的发芽势及发芽率的影响较清水对照差异显著。田间试验结果显示,在有效剂量为187.5 g/hm2时50%噻虫嗪悬浮种衣剂对棉花4、5叶期蚜虫的防效分别达83.94%和53.94%,适合田间应用。

Preparation of 50% thiamethoxam flowable concentrates for seed coating and its control efficacy on cotton aphid

The 50% thiamethoxam flowable concentrates for seed coating were prepared and their effect on the controlling of cotton aphid were increased. To construct the formulation, a series of wetting agent, dispersing agent, film-forming agent, thickening agent and other agents were screened and optimized by wet milling method and recurrent selection method. The wet milling method was ultimately chosen as the optimal method to prepare the 50% thiamethoxam flowable concentrates for seed coating which contains the following fomula: thiamethoxam 50% as active ingredient; FD 3% and BC-10 1% as wetting agent; SP-2836 2.5% and SK-24 2.5% as dispersing agent; veegum 1% and xanthan gum 0.05% as thickening agent and BF 308 2.5% as film-forming agent. Its quality index and effect on the germination potential and the germination rate of seeds were determined. The results showed that the above formulation had excellent morphology, high suspension rate, perfect heat storage stability, and its effect on the germination potential and germination rate of cotton was discrepant with that of the blank control. The further field experiment revealed that, when effective dose was 187.5 g/hm², the 50% thiamethoxam flowable concentrates for seed coating had an excellent control effect on cotton aphids in the 4-and 5-leaf stage of cotton, and the control effect was 83.94% and 53.94%, respectively. These results demonstrated applying the concentrates in the field was feasible.