Tiny Weed-Killing Robots Could Make Pesticides Obsolete

Clint Brauer’s farm outside of Cheney, Kansas, could be described as Old MacDonald’s Farm plus robots. Along with 5,500 square feet of vegetable-growing greenhouses, classes teaching local families to grow their food, a herd of 105 sheep, and Warren G—a banana-eating llama named after the rapper—is a fleet of ten, 140-pound, battery-operated robots. Brauer, the co-founder of Greenfield Robotics, grew up a farm kid. He left for the big city tech and digital world, but eventually made his way back to the family farm. Now, it’s the R&D headquarters for the Greenfield Robotics team, plus a working farm...When Brauer started thinking about which weed to target first, pigweed was an obvious first enemy. The pain-in-the-ass weed, also known as Palmer amaranth, claims the annoying weed holy grail — it is invasive, adaptive, and herbicide-resistant. A single plant, undeterred, can grow over six feet tall and produce up to half a million tiny seeds. It distributes easily, and young seedlings continue to germinate even after the cash crop is planted. Farmers have to keep working to get rid of it even after their crop starts growing, otherwise, it quickly takes over. Because it has become glyphosate-resistant, desperate farmers have increasingly turned to more aggressive chemical solutions. On a whim, Brauer threw a mower on his tractor and took it to a field that had been overtaken by the weed. He discovered that if mowed repeatedly, a few inches off the ground, the pigweed would eventually give up the fight and die. But when you mow down a field of pigweed, you’re mowing everything down. Including, technically, the crop you’re trying to grow. A standard-size tractor and mower won’t fit between rows of soy, corn, cotton, or any other broadacre crop, which are typically seeded in rows 30 inches apart. And a heavy tractor and mower can’t go into fields when it’s too wet, or they risk the catastrophe called “planting your tractor” — otherwise known as getting stuck. Plus, staying in front of pigweed’s lightning-fast growth rate would require an almost nonstop mowing regime. So, Brauer turned to robots. Autonomous mowing machines were small enough to fit between rows, light enough to work in muddy fields, and, the best part — they could do it by themselves. Better yet, a whole fleet of them could...MORE