Spray Performance of Drones for Fungicide Applications in Corn and Peanut

Abstract

Spray drone technology is gaining popularity in the United States as an alternative option to traditional manned aircraft and ground sprayer for pesticide applications. However, limited research exists on their performance for fungicide applications in corn and peanut, two major crops affected annually by fungal diseases. This research aims to evaluate the spray deposition, swath uniformity, canopy penetration, and efficacy of drone-based fungicide applications in these crops. Two-year studies were conducted using DJI T30 and T40 drones in corn. DJI T30 was tested at two spray volumes (18.7 and 46.8 L ha-1) and different application heights (2.2, 3.0, and 3.8 m) across the swath, while DJI T40 was tested at two volumes at 3.0 m height. Spray deposition was assessed using water-sensitive papers placed at different canopy positions (upper, middle, and lower). Actual fungicides were applied at both volumes to evaluate disease control and yield. Results indicated that spray volume significantly affected spray coverage and droplet density; however, flight height was non-significant for spray coverage. Higher volume at 3.0 m produced the highest droplet density. Disease control varied by year, with higher volume improving control in one year and no difference in the other, while yield remained unimpacted. A similar study was conducted in peanut where drone applications were compared with traditional ground sprayer throughout the season on various days after planting. Results suggest that the ground sprayer achieved higher coverage and droplet density compared to the drone. However, disease control was similar between the two methods despite the drone’s lower coverage. Both ground sprayer and spray drone followed a similar pattern where spray coverage was highest at the upper canopies, followed by the middle and lower canopies. Overall, these findings demonstrate that spray drones can provide effective fungicide applications in corn and peanut, offering a viable alternative to traditional methods. This research provides practical guidance for growers considering spray drone fungicide applications without compromising disease management.