Take Me to Your Weeder

Solar-powered robot could pick weeds and reduce herbicide use

Here's an innovative idea for limiting herbicide use: A solar-powered robot with 20/20 vision and depth perception that uses GPS navigation to search out and destroy weeds. As it moves along at three miles per hour, the two-foot-tall, five-foot-long robot, designed by engineers at the University of Illinois, can tell what is and isn't a weed; when it finds one, it reaches out and snatches it with a robotic arm, then applies herbicide to the cut stem. "This type of application is extremely effective," says agricultural engineer Lei Tian, "because it applies herbicide directly to the plant, instead of broadcasting uniform rates across a field." Tian came up with the idea when he was doing a project that required grad students to collect data from the farm field. "The grad students who collected this information stayed in the field most of the day, and one of them was fainting from the heat ... We could replace the grad student worker with this robotic system," Tian says. But can it write dissertations?