A New Age for an Age-Old Problem

Ken Giles gave a keynote speech on engineering developments in robotics and sensors at the International IPM Symposium. Source: K. Judd, Northeastern IPM Center

Imagine: A fleet of robots maneuvers through a field in which a multitude of different plants—among them carrots, corn, and cauliflower—are growing side by side. A miniature droid equipped with sensors tenderly nurtures the crops, taking various measurements, looking for nutrient deficiencies, water stress, or an impending disease. Challenges that have plagued farmers for hundreds of years could be met with precision care, yielding healthy crops that can withstand nature’s elements.

What might seem like a scene from Star Trek is indeed the direction that some growers are heading. The Northeastern IPM Center recently organized a session on this topic at the International IPM Symposium in Salt Lake City, Utah.

Experts see big opportunities in one area: how growers spray pest management materials. New machines could help farmers manage the droplet size of materials, reduce application rates, and mitigate spray drift. They could also minimize worker exposure and materials deposited on the ground. Making payloads smaller will reduce demands on farm vehicles, enable higher operating speeds, and boost productivity.

Prevention and Precision

Three objectives form the trifecta of precision IPM: efficacy of application, protection of non-targets, and productivity.

“Any successful technology has to improve one and at least be neutral on the other two,” said Ken Giles, a professor of engineering at the University of California at Davis (UCD), who was one of the keynote speakers at the session.

In an orchard, a successful example of this technology turns off spray nozzles between trees. Scientists collected data that showed a 15 to 40 percent reduction in materials when they used this technology.

Today, with sensors becoming more sophisticated, machines can get a better sense of the shape of the tree, and use mechanical actuators to better reach the target.

Another example is found in a lettuce growing operation.

“Lettuce grows very quickly, so the target is always changing,” said Giles. “To make matters even more difficult, only six to eight percent of the land is covered with the target crop.”

He and his UCD colleague David Slaughter did sensing and applicator work that allowed them to adjust the width of spray on the target, and deployed it in a 12-row system in lettuce. The result: a 60 to 80 percent reduction in materials used, and a 90 percent reduction in soil deposition in material that should have been on the plant.

“This system is now very common in the Salinas Valley of California,” said Giles.

Giles has seen some of his team’s developments take 10 to 15 years to come to market. But when they do, they have spread very quickly with many vendors providing products and services.

Robots in the Sky

Giles also sees big opportunities for crop protection using unmanned aerial vehicles (UAVs). In one recent study, his UAVs sprayed only water. Then, his team applied for a Part 137 exemption that allowed them to spray an active ingredient. They were required to follow the same aviation rules that apply to crop dusting. Looked at in terms of productivity, the UAVs were fast—in fact, multiple times faster. In an area where terrain, slope, and turns meant ground vehicles could cover one acre per hour or less, UAVs were able to cover three to seven acres per hour.

This idea may not be ready for mainstream use just yet: some product labels have specific instructions that preclude UAV use, and conflicts over airspace could arise, as manned commercial crop dusters operate in the same space.

While engineering developments can take several years to get to market, these new technologies could soon meet all three objectives of precision IPM: efficacy of application, protection of non-targets, and productivity.