有机磷农药对韭菜虫害的防治效果及农药的微生物降解

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

采用 3 0 0kg(a.i)·hm-2 辛硫磷和 2 6 3kg(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 2 8%和 98 39% ;2 0d后虫口减退率分别达到 89 94 %和94 0 4 % .用浓度分别为 15 0 0、18 0 0和 2 1 0 0kg(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 4 4 %、95 0 5 %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 4 5 0 0L·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 5 2 %和 98 83% ;2 0d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 0 0L·hm-2 降解菌剂 ,35d后不同辛硫磷施用量的降解率分别为 10 0 %、10 0 %和 99 6 9% .

3.00 kg(a.i)·hm -2 phoxin and 2.63 kg(a.i)·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)·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·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·hm -2 pesticide-degrading bacterium to control Bradysia odoriphaga,the degradation rate of three concentrations of phoxin was 100%,100% and 99.69%,respectively.