Drones can’t carry the volume that herbicide applicators cart across fields in massive rigs. But three businesses — Biosorb, Nardo Agribotics and Rantizo — argue they don’t have to. Well-timed applications of as little as 1 ounce per acre can treat the hot spots of a field when delivered by drone, company representatives say.

Agrichemicals for an aphid or waterhemp infestation will disperse more uniformly when an electrostatic charge is also applied from a drone, ensuring the tops and bottoms of leaves are covered, but modestly. To adhere a treatment, a sticker like Biosorb’s TopFilm is added to the mixture to make the pesticide bind and translocate.

“A lot of farmers know where their problems are. What differentiates us is we’re delivering solutions versus the other companies who are just gathering images,” says Rantizo CEO Michael Ott, referring to Normalized Difference Vegetation Index maps that identify areas of stress and infestation, as well as the most common use of drones in agriculture currently: data collection.

His company is in its second round of fundraising to “build integrated solutions” between current technologies such as NDVI imagery, drones and agrichemicals like TopFilm — known for its ability to adhere to algae for long durations without being washed off by wakes.

The combination holds potential for fighting algae blooms when and where they start, says Lucy Marshall, research and development leader for Biosorb. She recently co-led an event with Ott and Drew Smith of Nardo Agribotics, a company that specializes in programing drones, to educate golf course superintendents about using drones for aquatic applications.

“I would not use a drone on 50,000 acres,” Marshall says. “But, whether it’s the red tide or the blue-green algae, from space, you can find these problems early and take one of these little machines, fly it, and get there before it spreads, rather than treat the whole canal or waterway.”

Marshall says drone spraying can help many of her customers, which include farmers and communities from Florida to Missouri, reduce labor costs on their field and waterway maintenance. Biosorb is giving talks at events in Southern states such as Florida and Texas, where hundreds of aquatic applicators come to receive training on DJI sprayer drones.

Other than labor, the greatest cost savings comes from simply applying less spray through the precision and proximity of a drone, Marshall says.

“Drones nowadays have radar sensors, so you can really just program it to spray 2 feet over or 3 feet over,” she says. The caution? “Make sure there aren’t any trees around. [Drones are] only looking for the canopy.”

Who is drone spraying?
In terms of current adoption, Rantizo customers include hemp and other high-value crop growers. To grow its customer base, the company plans to build a matrix of recommended practices and drone-sized chemical spray cartridges for problem weeds and pests.

“If you wanted to do individual spot spraying, you could use a 4-ounce chamber like what we have on our prototype,” Ott says. “But if you want to do large and autonomous, and solve the problems that we have in agriculture, you need an integrative platform.” He says his young company is getting closer to making that platform a reality.

The platform can fly a drone and spray around the periphery of a golf course green without operator intervention, as Rantizo demonstrated in October at a country club outside of St. Louis. The only work involved was programming the flight — the drone flew itself.

PREPROGRAMMED: Rantizo Director of Technology Mike Schmitz holds the controls for a drone demonstration. The drone flies itself on a preprogrammed path.

As the platform incorporates more integrations such as auto-payments and refills for cartridges, Ott hopes to offer a service as effective as conventional spraying, but at a fraction of the cost.

Advantages of drones
Drones present a new option for applicators eager to spray their crops precisely and at will — a strategy at the center of fighting herbicide-resistant weeds. While heavy machinery can’t go into a field immediately after a heavy rain, drones have no impact on the ground.

Later in the season, like when corn tassels, drones can spray again with no crushing impact on stalks.

“Spraying is absolutely necessary, but there are consequences,” Ott says. “There’s soil compaction. We’ve got these heavy, slow pieces of equipment going through the field, pushing down on the roots and impacting your yield.

“There’s also drift,” he says, adding that if a farmer using the herbicide dicamba starts using a drone, there will be less drift, partly because less herbicide is used.