Drone Spraying: The Progress, Pitfalls, and Path Forward

The below X post includes a video illustrating the risks of poorly operated drone applications — in this instance, fungicide specifically.

On X throughout the 2025 season there have been images and videos conveying the inconsistency of drone swaths, specifically for quadcopters/rotary wing type drones (eg: DJI Agras T50) one of the major constraints of these kinds of drones moving from niche and spot spray focused to viable as a system for larger scale row crop farming.

The X posts are anecdotal, but the main point is that operator margin for error grows drastically when moving from ground sprayer to rotary/quadcopter type spray systems.

A few things to consider.

Note: I am expiclitly looking at rotary/quadcopter systems in the below.

Swath width and coverage consistency

The main problem comes back to swath width and spray coverage: with ground sprayers you know your swath. A 120-foot ground sprayer boom delivers essentially 120 feet under most conditions.

With rotary drones, swath width can be variable and unpredictable.

In one study highlighted in The Western Producer, a drone flying 3m above ground at ~30 km/h (~18.5 mph) and delivering 3 gallons/ac produced varying swaths:

• 21 ft swath

• 23 ft swath (30 minutes later)

• 16 ft swath (another 30 minutes later)

That’s a 25–30% swing in width within hours, producing striping from overlap and misses. Even great operators may struggle navigating settings and controls to account for subtle variations in temperature, humidity or wind that influence droplet deposition.

Multiple factors influence this inconsistency: flight height, speed, wind, rotor downwash, nozzle type, and even terrain undulation.

One study with a DJI T10 confirmed that:

• Higher altitude (4m vs 2–3 m) widens swath but increases drift.

• Lower volumes (1 US gal/ac) narrow swath and sometimes improved uniformity.

• Nozzle type changes distribution: very coarse droplets concentrate deposition in the center, finer droplets spread more, but then become higher risk to drift.

Every combination of conditions can produce a variable outcome.

The coverage can have significant impacts on ultimate performance and in a world of expensive input, low commodity prices and trying to squeak every dollar out of an acre, studies show a lot of room for error.

Consider this soybean trial finding where coverage and canopy penetration were lower than a ground sprayer:

The performance ultimately led to increased white mold severity in the soybean trial and decreased yield:

Some of that is coverage, other aspects might be product formulation related (more on that below).

Atomizers can help

I highlighted work from a Spray Expert Tom Wolf in Is John Deere Losing Ground in Drones or Is the Market Just Not Ready? surrounding atomizer capabilities.

Wolf shares:

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