Coordination of distinctive pesticide adjuvants and atomization nozzles on droplet spectrum evolution for spatial drift reduction

Pesticide adjuvants, as crop protection products, have been widely used to reduce drift loss and improve utilization efficiency by regulating droplet spectrum. However, the coordinated regulation mechanisms of adjuvants and nozzles on droplet spectrum remain unclear. Here, we established the relationship between droplet spectrum evolution and liquid atomization by investigating the typical characteristics of droplet diameter distribution near the nozzle. Based on this, the regulation mechanisms of distinctive pesticide adjuvants on droplet spectrum were clarified, and the corresponding drift reduction performances were quantitively evaluated by wind tunnel experiments. It shows that the droplet diameter firstly shifts to the smaller due to the liquid sheet breakup and then prefers to increase caused by droplet interactions. Reducing the surface tension of sprayed liquid facilitates the uniform liquid breakup and increasing the viscosity inhibits the liquid deformation, which prolong the atomization process and effectively improve the droplet spectrum. As a result, the drift losses of flat-fan and hollow cone nozzles are reduced by about 50% after adding organosilicon and vegetable oil adjuvants. By contrast, the air induction nozzle shows a superior anti-drift ability, regardless of distinctive adjuvants. Our findings provide insights into rational adjuvant design and nozzle selection in the field application. (c) 2023 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.