有机磷农药对韭菜虫害的防治效果及农药的微生物降解

采用3．00kg(a．i)·hm^-2辛硫磷和2．63kg(a．i)·hm^-2甲基对硫磷来防治韭菜蓟马。3d后与不施农药的对照相比，虫口减退率分别达到98．28％和98．39％；20d后虫口减退率分别达到89．94％和94．04％．用浓度分别为15．00、18．00和21．00kg(a．i)·hm^-2的辛硫磷来防治韭蛆，3d后与不施农药的对照相比，虫口减退率分别达到了80．77％、93．10％和96．98％；35d后虫口减退率分别达到了92．44％、95．0596和96．81％．施用降解菌剂对防治蓟马和韭蛆没有不良影响，但可显著降低韭菜中的农药含量．蓟马施药防治后3d喷施45．00L·hm^-2的降解菌剂，3d后与不施菌对照相比，辛硫磷和甲基对硫磷的降解率分别为99．52％和98．83％；20d后韭菜(苔)中农药含量均检测不出．韭蛆施药防治后3d灌施75．00L·hm^-2降解菌剂，35d后不同辛硫磷施用量的降解率分别为100％、100％和99．69％．

Effect of organophosphorous insecticides on Chinese chive insect pests and their degradation by pesticide-degrading bacterium

3.00 kg(a. i) x hm(-2) phoxin and 2.63 kg(a. i) x hm(-2) methyl parathion were respectively applied to control the Taeniothrips alliorum on Chinese chive. Compared to no pesticide treatment, the decline rate of the insect density was 98.28% and 98.39% at the 3rd day after spraying pesticides, and 89.94% and 94.04% at the 20th day after spraying pesticides, respectively. At the 3rd day after spraying 15.00, 18.00 and 21.00 kg(a. i) x hm(-2) phoxin, the insect density of Bradysia odoriphaga decreased 80.77%, 93.10% and 96.98%, and at the 35th day after spraying, it decreased 92.44%, 95.05% and 96.81%, respectively. The application of pesticide-degrading bacterium had not any effect on controlling insect pests, but could markedly degrade pesticide. At the 3rd day after spraying 45.00 L x hm(-2) pesticide-degrading bacterium to control Taeniothrips alliorum, the degradion rate of phoxin and methyl parathion was 99.52% and 98.83%, and at the 3rd after spraying 75.00 L x hm(-2) pesticide-degrading bacterium to control Bradysia odoriphaga, the degradation rate of three concentrations of phoxin was 100%, 100% and 99.69%, respectively.