Could Electricity Be A New Weed Killer?

Posted by Chris Bennett on Tue, 03/12/2019 - 13:43

One touch from old sparky and the current brings death by electricity. Could electricides serve farmers as the ultimate weed killer?

Against a backdrop of ongoing herbicide resistance issues and pesticide litigation, old and new technologies capable of sizzling weeds are attracting attention. RootWave combines a phalanx of cutting-edge electricide technology and aims for market entry in 2020. Lasco Lightning Weeder, an electrical discharge implement, is a late-1970s machine catching renewed interest from producers.

The concept and theory of electric control dates back to the 1800s, but successful mechanical transference to farmland was absent. However, the digital age has enabled technology to catch and pass supposition, according to Andrew Diprose, CEO of
UK-based RootWave.

RootWave will partner with Steketee on a pull-behind unit covering eight to 12 rows using camera imagery to spot and zap weeds on the go, rolling close to 3 mph, with power sourced from the PTO. Essentially, visual recognition identifies weeds in real time and RootWave delivers a 5,000-volt jolt without disturbing the soil.

The scalable unit serves all crop types and the voltage is flexible, Diprose explains. Initially, RootWave targets weeds up to 2". But the next step is to scale and adopt the technology to treat mature weeds as well.

Variations in soil types and moisture content sometimes require changes in voltage. There are also nuances with root type. “Fibrous or taproots aren’t an issue, but a rhizome may require multiple passes,” Diprose describes.

What about microbial activity subjected to electricity? RootWave has undergone environmental tests and Diprose says they don’t see it as a problem, though they’re awaiting a definitive and scientific answer.

And cost? “This will start as cost-comparable with herbicides, but in time, the potential is strong for a lower than chemical cost,” he adds. “There are basically no inputs other than capital depreciation.”

After almost 40 years on the market, Kevin Olson is the last Lightning Weeder dealer standing. Each year, he rents four units to soybean and edible bean growers in the Midwest and has several units for sale.

“This technology doesn’t hurt the soil; we’ve tested a lot and never found any negative results,” Olson explains. “There’s no damage to crops and no safety issues for drivers.”

A metal applicator bar is charged with up to 14,500 volts of electricity, powered by a PTO generator. According to canopy height, the bar can be dropped to the ground or raised just shy of 4' high. Any vegetation contacted by the bar receives a full dose of voltage. However, Olson recommends 30% reduced voltage for early season weeds, depending on moisture.

“If you’re running the bar over 5" to 6" weeds or less, you don’t need full energy because the power is so great you will carry a continuous arc that will destroy the crop,” he explains. “Later in the season, mature weeds get the maximum dose.”

Lightning Weeder has two models: 24' and 30'. The units can be front-mounted or used as a pull-behind unit. Olson suggests a tractor speed of 4 mph with low weed pressure and 2.5 mph with heavy weed pressure.

Olson intends to restart the manufacturing of Lightning Weeders. “I own the rights and I’ve been doing this since 1980. With a touch of the bar, the weed dies right down to the bottom of the root. Contact is death,” he says.

For more information about using electricity as a means to manage weeds, visit bit.ly/electricity-zaps-weeds

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