Spray performance of flexible shield canopy opener and rotor wind integrated boom-sprayer application in soybean: effects on droplet deposition distribution.

Abstract

Canopy density is high during mid-to-late soybean growth as a result of dense planting to improve yield, which seriously affects the control of pests and diseases. The dilemmas of difficult droplet penetration, nonuniform deposition, and droplet drift in field spraying remain challenges to the precise control of droplet distribution. This paper proposed a novel spraying application mode combined flexible shield canopy opener (FSCO) with rotor wind. The design of the key components of the new boom-spraying machine are described. The effects of the comparative spraying modes on spray deposition and droplet drift were studied in a field validation test to explore the feasibility of the novel spraying application. The study found that droplet coverage inside the soybean canopy was significantly affected by spraying mode, rotor wind speed and opener depth. The spraying operation that used the FSCO and rotor wind integrated mode was optimal for droplet uniformity on the adaxial and abaxial surfaces of the canopy leaves, with droplet uniformity indices of 0.966 and 0.934, respectively. At a rotor wind speed of 6 m s-1 and opener depth of 15 cm, the soybean canopy droplet coverage uniformity effect achieved the highest composite score of 0.937. The spraying mode used in this study improved droplet coverage uniformity by 82.30% and droplet anti-drift performance improved by 99.73% compared to the conventional boom-spraying mode. The study shows validity of the spraying mode combined FSCO with rotor wind to open dense canopy and improved droplet deposition uniformity in canopy and anti-drift performance. © 2024 Society of Chemical Industry.