不同浓度天然除虫菊素水乳剂防治蔬菜蚜虫田间药效试验

用1.5％天然除虫菊素水乳剂1000倍液、1500倍液、1800倍液、2 000倍液防治蔬菜蚜虫.试验结果表明,1 000倍液处理区药后1、3、7d平均校正防效分别为94.61％、94.90％、93.85％;1 500倍液处理区药后1、3、7d平均校正防效分别为91.68％、93.81％、93.20％;1 800倍液处理区药后1、3、7d平均校正防效分另为79.40％、83.98％、82.3％;2 000倍液处理区药后1、3、7d平均校正防效分别为73.14％、76.70％、73.12％;其中1 000倍液、1 500倍液的防治效果较好,1 800倍液、2 000液倍的防治效果稍差.

Field Efficacy Trial of Different Concentrations of Pyrethrin EW on Controlling Vegetable Aphids

The trial was carried out to study the control efficiency of 1 000, 1 500, 1 800 and 2 000 times liquid of 1.5% pyrethrin emulation in water （EW） on vegetable aphids. The results showed that, the average revised control efficiency was 94.61%, 94.90% and 93.85% after 1, 3 and 7 days of spraying the 1 000 times liquid. The average revised control efficiency was 91.68%, 93.81% and 93.20% after l, 3 and 7 days of spraying the 1 500 times liquid. The average revised control efficiency was 79.40%, 83.98% and 82.3% after 1, 3 and 7 days of spraying the 1 800 times liquid. The average revised control efficiency was 73.14%, 76.70% and 73.12% after 1, 3 and 7 days of spraying the 2 000 times liquid. The 1 000 and 1 500 times liquid of 1.5% pyrethrin EW possessed better control effects, while the 1 800 and 2 000 times liquid had relatively poorer control effects.