雾滴大小与施药液量对草甘膦在空心莲子草叶片沉积的影响

Influence of Droplet Size and Spray Volume on Deposition of Glyphosate on Alligator Weed Leaves

为提高草甘膦防治空心莲子草Alternantheraphiloxeroides时药剂的有效利用率,用丽春红S为示踪剂研究了草甘膦药液在空心莲子草叶片的沉积特性。结果表明,用体积中径(VMD)149.5～233.7μm的雾滴喷雾,草甘膦在空心莲子草叶片上的沉积量在体积中径为157.3μm时最多,随着雾滴体积中径增大,沉积量减少。雾滴体积中径157.3μm与施药液量339L/hm2处理的沉积量是雾滴体积中径233.4μm与施药液量694.5L/hm2处理的1.54倍。施药液量超过382.5L/hm2时,草甘膦药液的流失明显增多。800mg/L草甘膦药液在空心莲子草叶片上的最大稳定持留量约为4.92μg/cm2。结果表明,喷雾施药时采用小雾滴和较低施药液量,可大幅度提高草甘膦在空心莲子草上的沉积量。

In order to improve the efficacy of glyphosate controlling alligator weed(Alternanthera philoxeroides), deposition characteristics of glyphosate droplets on alligator weed leaves were studied by means of detecting a tracer substance, Ponceau S, added in glyphosate solution. In droplet sizes range from 149.5 μm to 233.7 μm, deposition of glyphosate on alligator weed leaves treated in the droplet size(VMD) of 157.3 μm was more than that treated in larger droplets. The deposition of glyphosate treated in spray volume of 339 L/hm^2 (droplet size 157.3 μm) was 1.54 times of that in spray volume of 694.5 L/hm^2 (droplet size 233.7 μm).The deposition of glyphosate was increased slightly when spray volume was higher than 375 L/hm^2,and the (maximum) deposition of glyphosate on alligator weed leaves was about 4.92 μg/cm^2 when treated under the concentration of 800 mg/L in droplet size of 149.5 μm. The results indicated that in relative small droplet and low spray volume the deposition of glyphosate on alligator weed would be increased greatly.