Objective The utilization rate and droplet distribution of pesticide sprayed by manual and electric sprayers in sweet corn fields were compared.

Method Plot experiments on pesticide utilization rates were carried out in sweet corn fields in Boluo County(Futian Town and Longhua Town) and Huiyang District(Pingtang Town and Liangjing Town) in Guangdong Province, and the pesticides included 5% chlorfenzobenzamide suspension concentrate(SC), 60 g/L spinetoram suspension concentrate(SC) and 2% emamectin benzoate micro-emulsion(ME). The pesticide spraying was performed by the seduction red tracer method, the field sampling was performed by the five-point sampling method, the fog-drop deposition and distribution were measured by filter paper and cardboard reflection, and the seduction concentration was determined by spectrophotometer(501nm) method.

Result The utilization rates of chlorfenzobenzamide, spinetoram and emamectin benzoate sprayed by electric sprayer were 40.22%, 41.57% and 39.99%, respectively, and the utilization rates of manual spray were 31.63%, 31.26% and 30.20%, respectively. The effect of electric sprayer treatment was significantly greater than that of manual sprayer treatment. The droplet deposition distribution results showed that both of deposition effects of manual and electric sprayer treatments gradually decreased from top to bottom, and the deposition effect of electric sprayer on corn plants was better than that of manual sprayer treatment. The results of droplet coverage area showed that the single droplet area in the middle layer of the two sprayer treatments was significantly higher than that in the lower layer, and the single droplet area in the middle layer of the manual sprayer was significantly higher than that under the electric sprayer treatment. The results showed that the number of droplets in the middle layer and the lower layer treated by the electric sprayer was significantly higher than that of the manual sprayer treatment.

Conclusion The utilization rate of three different pesticides sprayed by electric sprayer in trumpet period of sweet corn in Guangdong is higher than 39.99%, which is 8.59%-10.31% higher than that of manual sprayer, and the atomization effect of electric sprayer is better than that of manual sprayer, and it can better prevent and control diseases and insect pests on sweet corns.