吐温80对Bt在作物叶面的展着及葱田甜菜夜蛾防效的影响

在苏云金杆菌中,加入表面活性剂吐温80,研究了苏云金杆菌在不同作物上的展着及对葱田甜菜夜蛾防效的影响。试验结果表明,吐温80能显著提高Bt在作物叶面的展着量。药液在不同作物的展着量差异显著,吐温80的2 000倍稀释液,可使CAB109制剂在葱、玉米、羽衣甘蓝、菜豆、草莓、白菜、黄瓜和萝卜的展着量分别提高8.0、7.9、7.7、2.5、2.3、2.0、1.4倍和1.3倍;可使商品TB的展着量分别提高4.4、6.4、4.7、1.8、1.9、1.7、1.4倍和1.2倍。吐温80的1 000倍稀释液,可使CAB109与TB制剂将葱田甜菜夜蛾的虫口减退率分别从63.6%与43.3%,提高到84.5%与62.8%,显著提高防效。

Effects of Tween 80 on spreading of Bacillus thuringiensis on crop leaves and its control efficacy against Spodoptera exigua in scallion fields

In order to increase the control efficacy of Bacillus thuringiensis, spreading of B. thuringiensis on crop leaves and control efficacy against Spodoptera exigua were explored by adding surfactant Tween 80. The results showed that Tween 80 could significantly improve the spreading effect on crop leaves. There was significant difference in spreading effects among different reagents. The spreading effect of B. thuringiensis subsp. aizawai CAB109 was improved by 8.0 times, 7.9 times, 7.7 times, 2.5 times, 2.3 times, 2.0 times, 1.4 times and 1.3 times, respectively, and that of B. thuringiensis subsp. aizawai TB by 4.4 times, 6.4 times, 4.7 times, 1.8 times, 1.9 times, 1.7 times, 1.4 times and 1.2 times, respectively, by treatment of 2 000 × diluent of Tween 80 on scallion, corn, kale, kidney bean, strawberry, Chinese cabbage, cucumber and radish. By treatment of 1 000× diluent of Tween 80, CAB109 and TB could raise the decrease rate of noctuid populations in scallion fields from 63.6% and 43.3% to 84.5% and 62.8%, respectively, and their control efficacy were significant.