【摘要】 采用室内生物测定与田间试验相结合方法,研究了甲氨基阿维菌素苯甲酸盐药液浓度、雾滴密度和施药液量对小菜蛾防治效果间的关系。结果表明:当甲氨基阿维菌素苯甲酸盐药液质量浓度从80 mg/L提高至640 mg/L时,其LN50值(致死中密度)从148 droplet/cm2下降至3 droplet/cm2;雾滴密度从23 droplet/cm2提高至131 droplet/cm2时,其LC50(致死中浓度)值则从1.66!102mg/L下降至78.93 mg/L。甲氨基阿维菌素苯甲酸盐在与地面呈0°倾角的载玻片正面和90°倾角的载玻片反面上沉积量最多,在45°倾角的反面和90°倾角的正面上沉积量最少;在甘蓝叶片上的沉积量与药液质量浓度和雾滴大小有关。田间药效试验结果表明:甲氨基阿维菌素苯甲酸盐药液质量浓度为3 mg/L时,施药液量为330 L/hm2的防治效果比施药液量分别为525、750和975 L/hm2的低,差异达显著水平(P<0.05),但后3种施药液量之间的防治效果差异不显著(P>0.05);当药液质量浓度为4.2 mg/L时,330、525、750和975 L/hm24种施药液量间的防治效果差异均不显著(P>0.05)。因此,采用较小雾滴体积中径(VMD=128.9μm)和较高药液浓度(4.2 mg/L)喷雾时,甲氨基阿维菌素苯甲酸盐不仅对小菜蛾表现出优良的防治效果,而且施药液量也显著降低。更多还原

【Abstract】 The relationship between concentration,droplet density,spraying volume and the efficacy of emamectin benzoate against diamondback moth w ere studied by the technology of bioassay inlaboratory and field test. The results indicated that the LN50( median lethal number of droplets per unit area) value dropped from 148 droplet/cm2to 3 droplet/cm2w hen the concentration of emamectin benzoate increased from 80 mg/L to 640 mg/L. The LC50value of emamectin benzoate changed from 1. 66 × 102mg/L to 78. 93 mg/L as the droplet density increased from 23 droplet/cm2to 131 droplet/cm2. The maximum deposition of emamectin benzoate w as observed on the front side of glass slides w ith 0° angle and the back side of glass slides w ith 90°,and the minimum w as observed on the back side of glass slides w ith 45° angle and the front side of glass slides w ith 90° angle. The deposition of emamectin benzoate on cabbage leaves w as affected by droplet size and concentration of emamection benzoate. At concentration of 3 mg/L,the efficacy of emamectin benzoate in fields spraying w ith 330 L/hm2w as low er than that of spraying w ith 525,750 and 975 L/hm2. How ever, the efficacies in fields spraying w ith 525,750 and 975 L/hm2have no significant differences. At concentration of 4. 2 mg/L,the efficacies of emamectin benzoate spraying w ith different volume w ere similar. Hence,emamectin benzoate exhibited excellent controlling efficacy to diamondback moth and the spraying volume decreased significantly under condition of spraying w ith smaller droplet size( VMD =128. 9 μm) and higher concentration( 4. 2 mg /L).更多还原