叶片倾角、雾滴大小与施药液量对毒死蜱在水稻植株沉积的影响

Influence of leaf incline angle,droplet size and spray volume on deposition of chlorpyrifos on rice plants

为提高农药的有效利用率,用丽春红为示踪剂研究了毒死蜱药液在水稻叶片上的沉积特性。随着水稻叶片的倾角变小,毒死蜱的沉积量相应地减少。用体积中径(VMD)为149.5μm 的雾滴处理,在设定叶片倾角为90°、60°、30°时,毒死蜱沉积量分别是直立叶片上沉积量的10.2、5.8、2.9倍。随着叶片倾角变小,雾滴 VMD 对沉积的影响增大,在90°、60°、30°、0°四个叶片倾角,用 VMD149.5μm 雾滴处理的沉积量分别是用 VMD 233.7 μm 雾滴处理沉积量的1.5、2.1、3.3、5.5倍。在施药液量170～1.36×10~3 L/hm^2范围内,毒死蜱沉积量随施药液量的增加而减少。用浓度为800 mg/L 毒死蜱药液在水稻叶片上测定的最大稳定持留量约为4.66μg/cm^2。结果表明,采用小雾滴与低容量喷雾,可显著提高毒死蜱在水稻叶片的沉积量。

In order to improve the efficient application of chlorpyrifos in rice(Oryza sativa)field,deposition characteristics of chlorpyrifos droplets on rice leaves were studied by means ofdetecting a tracer substance,Ponceau S,added in chlorpyrifos solution.Depositions of chlor-pyrifos on rice leaves decreased tremendously with decrease of rice leaf incline angle.Deposi-tions of chlorpyrifos on rice leaves with incline angle of 90°,60° and 30° were 10.2,5.8 and2.9 times more than that of vertical leaves,respectively,when sprayed with ST110-01 nozzle at0.2 MPa.The effect of droplet size on deposition of chlorpyrifos on rice leaves was also dis-tinct.Under leaf incline angles of 90°,60°,30° and 0°,the deposition of chorpyrifos spraysolution with small droplets(VMD 149.5μm)were 1.5,2.1,3.3 and 5.5 times more thanthat with coarse droplets(VMD 233.7μm),respectively.The deposition of chlorpyrifos onrice leaves decreased with the increase of spray volume in a range from 170 L/hm^2 to 1.36×10~3 L/hm^2.The maximum retention of chlorpyrifos on rice leaves was about 4.66μg/cm^2 trea-ted with chlorpyrifos spray solution under the concentration of 800mg/L.The results indicatedthat the deposition of chlorpyrifos on rice leaves would be improved greatly with decreasingdroplet size and spray volume.