印楝素对亚洲玉米螟的毒力与防效及对寄主作物 高粱的安全性评价.

[Objectives J The study aimed to study the control effect of botanical pesticide azadirachtin against Ostrinia furnacalis in sorghum. [ Methods J The activity of azadirachtin against 0. furnacalis was determined by diet incorporation method in the laboratory, the control efficacy was investigated in the three sorghum fields, and the safety evaluation on three sorghum varieties was determined by pot method. [ Results J Under indoor condition, the LC50 value of 2nd ins tar larvae was 6.44 mg· L- 1 , and the activity was relative high. The efficacy on plant protection and insect control effects in three provinces were ranged from 80.07% to 89.26% and 73.51 % to 87.31 %,and those were significantly better than control pesticides. The growth inhibition rate of 0.3% azadirachtin emulsifiable concentrate at the dosage of 18 g • hm - 2 was significantly higher than 4.5, 9 g • hm - 2 for three sorghum varieties, one plant of all three sorghum varieties showed leaf edge chlorosis,and one plant of 'Chiza No.16' showed leaf edge chlorosis of 0.3% azadirachtin emulsifiable concentrate at the dosage of 9 g • hm - 2 after 14 d of spraying, the growth of three sorghum varieties was normal and safe for sorghum. [ Conclusions] Azadirachtin had good toxicity activity and control effect against O.furnacalis,and it was safe for sorghum. [ABSTRACT FROM AUTHOR]