Evaluation of Spray Characteristics of Pesticide Injection System in Agricultural Drones

Purpose: This study aims to verify that the characteristics of the typical injection pumps and nozzles used in pesticide injection systems in current agricultural drones in Korea are consistent with those presented in the product specifications, and to provide experimental quantitative data for selecting the correct pump and nozzle. Methods: The performances of three types of pumps and 18 types of nozzles currently in use were evaluated in terms of the pressure-flow rate curve, injection flow rate, spray angle, and droplet size. Results: For pesticide injection pumps, the maximum pressure and pressure-flow rate curve should include the nozzle’s injection pressure and flow rate range. Most of the 18 nozzles used in the test showed nearly the same results as the flow rates suggested from the manufacturer, but the spray angle showed a difference of up to 10%. The droplet size was slightly smaller than the value suggested by the manufacturer, and the relative span factor ranged from 0.2 to 1.2. Conclusion: The pressure-flow rate curves of the injection pumps and spray angles of the commercial nozzles used for agricultural control drones must be evaluated for official approval/assessment of such agricultural drones to ensure the performance of agricultural drone sprayers.