Optimizing UAV spray parameters to improve precise control of tobacco pests at different growth stages

BACKGROUND: Unmanned aerial vehicles (UAVs) for pesticide application show promising potential in tobacco pest management. However, the impact of flight parameters on spray efficacy requires further investigation. Three field experiments were conducted from the rosette to the maturation stage of tobacco to systematically assess spray efficacy under varying flight heights, speeds, and application volumes. Using a multi-index weight analysis method, optimal operational parameter combinations for different tobacco growth stages were evaluated and compared with backpack electric sprayers. RESULTS: For the rosette stage, the recommended parameter is a flight speed of 5 m s(-1), a flight height of 2 m, and a liquid application volume of 30 L hm(-2); during the vigorous growth stage, the suggested parameter includes a flight speed of 3 m s(-1), a flight height of 2 m, and a liquid application volume of 22.5 L hm(-2). In the maturing stage, optimal parameter consists of a flight speed of 3 m s(-1), a flight height of 3.5 m, and a liquid application volume of 30 L hm(-2). Furthermore, UAV spraying achieves higher droplet deposition on both sides of tobacco leaves compared to traditional electric backpack sprayers. CONCLUSIONS: Adjusting UAV spraying parameters for different tobacco growth stages is crucial. These results can provide the methods for the precise control technology of tobacco pests at different growth stages. (c) 2024 Society of Chemical Industry.