水稻叶片上露水对农药沉积量的影响

Influence of dew on pesticide droplet deposition on rice leaves

水稻叶片表面独特的微纳米结构是造成农药雾滴在叶片上难以持留的主要原因,叶片上凝结的露水会改变叶片表面的微结构,从而对农药雾滴的沉积状态产生影响。针对这一问题分别进行了田间试验和实验室模拟试验,通过高速摄影以及农药沉积量试验研究没有露水、露水量较少和露水量多3种情况下,使用标准扇形喷头与防飘射流喷头进行喷雾时的农药雾滴沉积。试验结果显示,叶片上露水的存在能够增加农药雾滴的沉积并且影响显著,且不同喷头间存在显著性差异。高速摄影试验结果显示,露水的存在减少了雾滴的弹跳情况,农药雾滴在沉积过程中雾滴与叶片的直接作用变为农药雾滴与露水的作用,从而增加了沉积。

The unique micro/nano structure of rice leaf surface is the main reason that pesticide droplets could not deposit on the leaves.Dew frozen on the leaves will change the microstructure of the rice leaf surface,and could influence the deposit of pesticide droplets on rice leaves.In order to solve this problem,the experiment was divided into two parts,indoor experiments and field tests.The depositions of pesticide were tested on three conditions：no dew,a little dew,and much dew.At the same time,by using high-speed photography,an intuitive observation was done for the influence of dew on pesticide deposition.The experiment chosen different types of nozzles to spray.The results show that the existence of dew on rice leaves can increase the pesticide droplets deposition significantly.And the difference between nozzles is also significant.High-speed photography experimental results show that the existence of dew can reduce the bounce of droplets.The direct contact between pesticide droplets and leaf is changed into the contact between pesticide droplets and dew,which improves the deposition.