喷雾助剂对农药雾滴蒸发特性影响研究

Effects of pesticide adjuvants on spray pendant droplet evaporation

雾滴蒸发飘移是农药利用率低下的重要原因之一,喷雾助剂的使用是减少蒸发飘移的主要方法,但目前助剂溶液的蒸发规律及抗蒸发机理尚未明确。为了探究喷雾助剂对雾滴蒸发过程的影响,研究以水和植物油类助剂倍达通、矿物油类助剂迈道、非离子型表面活性剂Silwet408这3类喷雾助剂为对象,通过可控温控湿的单雾滴蒸发实验平台模拟农药施药条件,采用悬滴法考察各助剂溶液的蒸发特性。结果表明,倍达通、迈道和Silwet408这3种助剂的蒸发抑制能力随相对湿度升高而减弱,随环境温度升高先增强后减弱,分别在30、30、28℃达到最佳蒸发抑制效果。此外,还测试了4种典型气象条件下各类助剂的蒸发抑制能力,并从蒸发角度提供了助剂选择参考。

Spray droplet evaporation is one of the main reasons for low pesticide utilization efficiency and can be reduced by adding pesticide functional adjuvants.However,the evaporation rate and mechanism with adjuvants are not clear.In this study,evaporation characteristics of water,vegetable-oil adjuvant(Beidatong),mineral-oil adjuvant(Maidao)and organosilicon adjuvant(Silwet408)under controllable climate conditions were investigated by a pendant-drop method.The results show that all three adjuvants can reduce evaporation rate compared with water.The anti-evaporation ability can be enhanced with low relative humidity,while it increases and then decreases with temperature.The three adjuvants show the best evaporation inhibition effects at 30℃,30℃and 28℃,respectively.The results can provide theoretical guidance for adjuvant selection under four typical meteorological conditions.