Abstract:In order to research on influence of spray operating parameters on droplet deposition, four kinds of spray pressure, air-blast velocity, travel speed, and three kinds of sampling height, were set to testing droplet coverage in artificial tree canopy and deposition shelf (sparse canopy), using orchard axial-fan air-assisted sprayer. Results showed that spray pressure had no significant effect on droplet deposition. To reduce-travel speed could increase droplet deposition on leaves frontside and backside. To increase air-blast velocity could increase droplet deposition effectively on leaves backside. According to the regression analysis, all the spraying parameters had significant effect on droplets deposition. But influence degree was different, the parameters order from strong to weak by influence degree were sample height, speed, air-blast velocity and spraying pressure.