The application of drone technology started with question marks, but two viable use cases have emerged: using consumer-grade RGB camera drones for stand counts and scouting, and using spray drones when weather or timing restrict a ground rig.
Artificial intelligence (AI) and automation advances in flight planning software have made getting stand count and directed scouting data extremely user-friendly. However, there are likely things you could be doing to get more out of your spray drone.
“This is the one thing farmers need to know: Just knowing how to fly a drone doesn’t get you very far,” says Steve Li, associate professor and Extension specialist, crop, soil and environmental sciences, Auburn University. “There’s a lot more you need to learn about pesticides and pesticide application.”
Li is widely recognized as one of the foremost researchers and experts in using spray drones for agriculture. He began working with drones during the COVID-19 pandemic, and it turned out to be the perfect complement to his 20-plus years in pesticide application and efficacy research.
Top Spray Drone Tips
As you gear up for spray season, consider what the experts have to say:
1. Do your homework before buying.
“Do your research and understand the opportunities and challenges with the technology because nothing is perfect. Spray drones are shiny and everyone’s excited when a new one comes out, but you have to realize the challenges associated with drones,” Li says. “You’re going to be working outside, refilling tanks and changing out batteries, you’re not in an air-conditioned tractor. It’s physically challenging. I know a farmer in Illinois who sprayed all summer and ended up losing 20 lb.”
2. Bring Your Own Trailer (BYOT). There are custom-made drone trailers you can purchase.
These will typically include an integrated generator for charging batteries, a nurse tank for refilling the spray tank, as well as anything else you’ll need to keep that drone spraying. Erickson says many farmers can save money by adapting an old trailer already on the farm and building out their own drone trailer.
3. Scout before flying. Do a thorough pre-flight planning scout of any field you want to spray.
Make sure you consider any oddly shaped fields or sections, look at weather reports and be aware of any nearby sensitive crops. It’s also important to find a clear, safe spot nearby to take off from and land the drone. If you’re doing in-season fungicide applications, you don’t want to be traipsing through chest-high corn or thick soybean canopies to refill the drone or do a battery swap.
4. Always follow the product label.
This is no different than if you were applying product using a ground sprayer. Products that are approved for drone application will have a specialized label for aerial applications. Make sure you follow that label closely because the label is the law.
5. Droplet size matters.
One of the most common and avoidable mistakes Li sees is using the wrong droplet size. He says it’s best to use small droplet sizes when spraying fungicide on corn or soybeans.
“The recommended droplet size is around 200 to 250 micrometers, which you can set on your controller,” he says. You don’t want to exceed 300 micrometers, or your droplet size will be too big, and you’ll get inconsistent coverage or streaking, he adds.
6. Mind wind speed.
Don’t try to make applications in strong winds. Ideally only apply when the wind speed is between 5 mph to 10 mph.
7. Don’t fly too fast or too high above the crops.
Drones are a nice tool to have, but the technology has limitations. Hylio founder and CEO Arthur Erickson says flying too fast or too high doesn’t get adequate penetration into the canopy. He advises you stay within 10' to 15' above the canopy and don’t fly faster than 22 mph while spraying.
“You need the downwash from the props to push that spray into the canopy and coat the leaves, even the undersides,” he explains.
What America’s First Spray Drone Company Told Us
Iowa-based Rantizo has been in the spray drone business since the very beginning. The company was the first to bring DJI spray drone airframes into the U.S. and the first to obtain an FAA exemption to swarm up to three drones at one time. Rantizo recently announced the availability of the XAG P150 drone, which the company says is currently the largest and fastest spray drone on the market in the U.S.
The company has built out a hub and spoke service model where experienced, knowledgeable crews and drone pilots are stationed around the country for hire at a per-acre structure.
But what Zach Hanner, agronomy operations lead for Rantizo, is most excited about is the continuing expansion of how spray drones can be used to cover more acreage.
“We’re seeing FAA approve exemptions for no visual observers, and we’re seeing swarming approved for night ops,” Hanner says. “We’re excited because that will expand the application window. When it’s 90° with 80% humidity, we shut down. Now, we’ll be able to get back out there at night, when the plants are starting to come out of their heat stress. Being able to accommodate those specific timings is going to be huge for us.”
While Rantizo flight-ops team members like Hanner focus on optimizing the drones in-field, CEO Mariah Scott can take a bit of a higher-level view. She’s excited to see the application of artificial intelligence come into spray drone flight planning software because it will be able to make the technology even more efficient.
“It’s a combination of the same AI that’s being used in crop scouting tools to identify areas of pressure, now we’re using AI to scan the crops and say ‘let’s only spray here, here, here and here,’” Scott explains. “We can get maps made and send the drone out to those specific areas, and now we’re not spraying all 500 acres. We’re just spraying these places where we have used the AI to identify issues.”
Drone service provider talks emerging use cases
Farmers are deploying spray drones mainly in two production scenarios: using the drones to spot apply contact herbicides in post emergence in fields with high weed pressure, and using them to apply foliar fungicides in corn.
Sam Thier, drone sales representative, Agri Spray Drones, told Farm Journal at Commodity Classic this year that farmer interest in drones is trending up and there are a handful of “niche” or emerging applications that farmers are beginning to recognize:
- Liquid Application of Regenerative Ag (Biological) Products: Many farmers are just starting to utilize spray drones to apply various liquid regenerative, or biological based, products. One example is former national corn yield contest winner Russell Hedrick. In 2024 the North Carolina farmer used a drone to liquid apply biological products 13 times in a single season. That same season, Hedrick shattered the all-time record for dryland corn yields at 460 bushels per acre, according to Thier.
- Rapid Response After Rain: Spray drones allow farmers to quickly return to the fields for work immediately after rain, which is a significant advantage over traditional ground rigs that will often require more time and drier ground to return to work.
- Swarming to Cover More Ground: The ability to use multiple drones in a coordinated swarm can really enhance the technologies efficiency and how many acres you can cover in a day, Thier told us.
“We are seeing a lot of farms getting into these drones right now because one new spray drone is $42,500, and a brand new ground rig is going to set the farmer back anywhere from $500,000 to over a million dollars for a brand new, high clearance Hagie,” Thier says. “And you have higher expenses operating ground machines. The drone costs them next to nothing to operate. It’s 15 gallons of gas per day to run through your generator to run the drone all day.”
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