Drone sprayer shines in high-value hort crops

Maverick chief executive officer Adam Shaw, left, and pumpkin farmer Bear Bouwman discuss Bouwman’s move to the larger T40 application drone. | Maverick photo

A pumpkin and watermelon grower from southern Minnesota was looking for a way to avoid tire damage to his crops

Bear Bouwman is a commercial pumpkin and watermelon grower in southern Minnesota. His crops need constant protection from pests. Disease, especially, can extract a mighty financial toll.

Until this year, Bouwman relied on a conventional ground sprayer, but he didn’t like the tire damage. Crushed vines while spraying insects and weeds resulted in small fruit or no fruit at all. Fungicide application with a ground sprayer was even worse. Vine damage was compounded by the fact that tires spread a disease hot spot in one area to other areas of the field.

In a phone interview, Bouwman said he had given no thought to drone application until last winter when he started researching unmanned aerial vehicle sprayers. He said it’s pure coincidence that Maverick, the company he finally picked to deal with, had its head office just a 20-minute drive from his farm.

“We’re in a hilly wooded area. Pilots don’t like our terrain. Quite honestly, our hills can be a risk. It would be a challenge for a pilot to follow the field contours safely. With the drone, we set the altitude at 12 feet and it goes up and down following the contour of the field as well as a ground sprayer.”

He says there’s also a scheduling problem. When he sees disease, he needs it sprayed immediately because of the high crop value. Helicopters can’t respond that quickly. This was a major factor in his decision to get a drone.

“Before I contacted Maverick, I had found enough information online to convince me that drones would solve a lot of our application problems,” said Bouwman.

During the 2021-22 winter, he became a licensed commercial aerial applicator. He bought a T30 from Maverick and started doing test sprays with water sensitive cards in April. The drone met his expectations.

Over the summer, neighboring farmers asked Bouwman to do some spraying. He custom sprayed 3,000 acres, about 80 percent in corn. He says when the corn is tall, growers appreciate dexterity and maneuverability of the small drone.

“We have free RTK in Minnesota. If you’re further out and you need precise accuracy, people use an RTK base station on the ground. But I found we didn’t need full RTK. So, what I’ve ended up using for fungicide is just the GPS.

The basics of applying crop protection products with a small 30 litre tank isn’t all that different from a larger operation — a support trailer and handling equipment are still needed. Bouwman says the T30 returns to the trailer every eight minutes for a tank fill and fresh battery. | Maverick photo

“I only had one missed strip in 2022. I was spraying herbicide on some beans and there was an eight-inch skip. I had gone back to fill the tank. When I returned to catch that strip later, we had some satellite drift, and we were eight inches off. All those issues can be eliminated if you use the full RTK signal.”

Bouwman sets the speed at 15 m.p.h., slow enough to ensure he’s getting uniform coverage. He thinks that speed does a better job than the higher speed used by a full-size helicopter. Altitude is generally 10 to 12 feet. Although the sales information claims a 30-foot wide swath, his testing with water sensitive paper says 24 feet is more realistic. In perfect conditions he might bump that to 26 feet.

“Quality of the spray job is a bigger benefit than we expected. When we’re spraying fungicide on corn, for instance, we see droplets all the way down to the root ball.”

The T30 uses T-Jet nozzles, leaving it up to the pilot to adjust speed, altitude and droplet size. The controller on the new T40 is smart enough to make those adjustments. After one season with the T30, Bouwman did not hesitate to order a new T40, which he expects to be delivered this month.

Is there a place for drone sprayers in broad acre crops?

“No, not right now, but at some point, in the future I think the technology will be available. The controller needs to accurately manage the drone even when it’s a mile away. And the payload has to be a lot bigger. Technology in agriculture is moving so fast, it’s really hard to make those predictions.”

Source: Western Producer
Date: Published: October 13, 2022
By: Ron Lyseng
Link: Drone sprayer shines in high-value hort crops | The Western Producer