My first experience with a drone, also known as a UAV or UAS, was during a field visit where a farmer was using one to scout the extent of corn lodging within his fields. His drone suddenly went down, and I had to help to find it. The next flight ended in destruction when it collided with their barn. Now, all drones have a GNSS receiver and multiple sensors for collision avoidance.

My agronomic view is that a fungicide application by drone may not necessarily be a total replacement for a ground application of fungicide, but a drone is most certainly another viable option—especially in a year when the field might be too wet or the corn is lodged from wind. I think more research needs to be done to know if a drone application is better than a ground application; however, there are most certainly pros and cons to both methods of fungicide application which is what I’ll share in this blog.

Until 2023, the main use of spray drones in the United States was for fungicide applications on wheat, corn and soybean acres. Though small, drones can include all the components of large ground sprayers and conventional aerial sprayers -and each component plays a critical role in achieving maximum spray performance.

Most commercial spray drones are multi-rotor types. Their propellers create turbulence in the canopy, which can significantly improve droplet penetration into lower parts of the canopy when compared to traditional ground sprayers that are not air-assisted. Multi-rotor drones are similar but vary in the number of rotors, rotor positions, nozzle locations and configuration, type and number of nozzles, distance between nozzles, and vertical distance between the rotors and nozzles under them. Some of the newer, more expensive drone models have larger 10-gallon spray tanks with multiple nozzles per outlet, larger batteries capable of handling heavier payloads, and wireless connectivity.

So far, drone configurations are not standardized. Credible, replicated studies are still underway to determine the most optimum drone design parameters for minimizing drift and maximizing deposition and spray coverage on the target. Due to the wide variation in drone designs, some published performance data may not be useful. Future developments in drone sprayer designs, capabilities and regulations are changing rapidly.

Below are some pros and cons of drone fungicide applications:

Resources:

Drones for Spraying Pesticides—Opportunities and Challenges | Ohioline

Can Fungicide Applications via Drones Effectively Control Soybean Foliar Diseases? – Research Highlight – Soybean Research & Information Network – SRIN