Fluorescent marker technology could be a major weapon in weed battle
In the field, how do the robotic knives of judgment distinguish saint from sinner? One of the roadblocks to commercialization of robotic technology for tasks such as weed control is the ability for a machine to recognize crops growing amongst weeds in a natural environment. The solution might be novel fluorescent marker technology. Essentially, a robot asks questions, and the plant responds with its precise location. It all happens with light.
This concept of a seminal project led by David Slaughter, professor at University of California–Davis, is to allow for direct signaling—makingit easier for a computer to identify which plant parts belong to crops and which to weeds. Slaughter is working with researchers at the University of Arizona, Washington State University, University of California–Davis and Aginnovation—a corporate partner and founding member of the Centor Group, a global seed technology alliance of companies.
A fluorescent systemic marker is applied via seed treatment, seed coating or seed encrusting/pelleting. As it germinates, the marker is drawn through the plant and extends to the foliage. The plant takes on an unique fluorescent appearance. When the plant is stimulated with a special color of light, it emits a fluorescent color. Essentially, it acts like a signal.
“Historically, we’re thinking of a vehicle like a spray thinner in lettuce or mechanical hoe systems pulled by a tractor, similar to pulling a planter,” Slaughter says. “However, there’s nothing preventing these vehicles from becoming autonomous and able to move under their own propulsion.”
Slaughter’s work is funded through USDA’s National Institute of Food and Agriculture program for specialty crops. The research is currently focused on vegetables, but the concept isn’t restricted to a particular crop.
He hopes to have a prototype ready within two years and a commercial product in five to 10 years. The current bottleneck involves identifying crops from weeds with a high degree of accuracy and doing so at a commercially viable speed, Slaughter says.
The fluorescent marker technology is part of Aginnovation’s Track and Trace Systemic Marking product line.
“Fluorescence in the plant tissue can be observed like a glow-in-the-dark object through special optics under Slaughter’s design,” says Peter Marks, general manager, Aginnovation. “The systemic marker in the plant must be excited with a certain wavelength of light detected by a robotic machine. You can’t see the marker with the naked eye. By using optics, we look for that particular marker, and a given plant is noted for keeping, eliminating or maybe counting.”
The technology has many possibilities: mechanical thinning, weeding, plot management, plant populations and more. Aginnovation is evaluating how long the systemic marker effects will last in different species. Currently, fluorescence lasts into the early stages of crop development. Aginnovation has only worked with vegetables, but plans to extend the technology into corn, cotton and soybeans.
