DAVIS, Calif. — Weed control without herbicides, tillage or hoeing may seem like magic but new research into electrified metal mesh is showing promise for vineyards, orchards, blueberries and other high-value crops.
Funded by the Western Integrated Pest Management Center through a competitive grant, research in New Mexico and Oregon is developing and evaluating “electric mulch” weed-control systems that use a low-power current in steel screens set within rows to kill weeds as they sprout. Small solar panels power the system.
“We’re using two different types of screens and testing them against pre-emergent herbicides and plastic weed barriers for weed control,” explained Erik Lehnhoff, an associate professor of weed ecology and management at New Mexico State University. “We installed them in April and we’re seeing very good weed control compared to the control plots, and even to the herbicide plots which now have an abundance of weeds in them.”
The experiment is being conducted in a cabernet vineyard in the university’s research farm in Las Cruces, with a second trial in a blueberry field in Oregon. The two types of screen have different-sized mesh – one a tighter weave and one more open.
“The general concept of how these screens work is that it takes a weed to complete the electrical circuit,” Lehnhoff said. “The solar panel generates the electricity which flows through a wire to the screens, but it needs a connection to go from the screen to the ground. The weed is that connection. There is no actual electricity flowing until a weed comes up and touches the screen and that completes the circuit.”
In the vineyard, it’s easy to see the concept in action. The narrow-mesh screens are almost entirely weed-free while a few thin, spindly weeds poke through the larger holes in the more open-mesh versions. Those skinny weeds have been lucky enough not to make contact with the screen, but eventually get large enough to touch the metal and die.
Lehnhoff’s ongoing research will determine how much mesh coverage a single solar panel can power, discover what irrigation practices are compatible with the system and develop a commercial cost analysis.
“It’s going to be most economically feasible in high-value crops, and one of the best applications would be in organic systems where herbicides are not used,” he said. “This could eliminate the need for a lot of hand-weeding within rows, which has a huge labor cost.”
Read the full story about the research at http://westernipm.org/index.cfm/ipm-in-the-west/agriculture/testing-electric-mulch-for-weed-control/
Watch a short video about the project at https://youtu.be/-Khu7LbpnxY
The Western Integrated Pest Management Center is supported by the U.S. Department of Agriculture’s National Institute of Food and Agriculture to develop and promote safe and sustainable pest management in 17 Western states and territories. The Center’s annual grant program is currently accepting applications, with $320,000 available for new projects in 2024.
Visit www.westernipm.org to learn more.
–Western Integrated Pest Management Center
