苏云金杆菌WP防治菜青虫田间药效试验

Controlling effects of Bacillus thuringiensis WP against Pieris rapae in field trial

进行苏云金杆菌WP防治菜青虫的田间药效试验,结果表明:药后3～7 d每667 m2使用苏云金杆菌WP不同剂量处理对菜青虫的校正防效均高于4.5%高效氯氰菊酯EC 30.0 mL。药后1d苏云金杆菌WP 33.3 g处理的平均校正防效仅为26.41%,速效性较差;但药后3 d和7 d其校正防效分别为83.18%和74.80%,防效较持久与稳定。生产上建议每667 m2苏云金杆菌WP的使用剂量以33.3 g为佳,施药期应比使用化学农药提前2～3 d。

Controlling effects of Bacillus thuringiensis WP against Pieris rapae were carried out in field condition. The results showed that corrected control effects of different doses （per 667 m^2 ） of B. thuringiensis WP were all better than 30 mL of 4.5% cypermethrin EC within 3 -7 days after treatment. The quick efficacy of B. thuringiensis WP was poor, the corrected control effect in the treatment of 33.3 g B. thuringiensis WP was only 26.41% at one day after treatment, but was 74.80% -83.18% within 3 -7 days after treatment and its controlling effects lasted and maintained stable for a long time. It was suggestion that the best doses of B. thuringiensis WP was 33.3 g per 667 m^2 and the application time needs to be moved up 2 - 3 d. ahead of chemical pesticide.