Given that more weeds develop resistance to herbicides, electrocution may be the weed management approach of the future, according to Missouri University (MU) Extension weed scientist Kevin Bradley.

MU graduate student Haylee Schreier has studied weed electrocution in row crops for the past two years under Bradley’s direction, according to a press release published by MU officials.

That is of special interest to Bradley because it might be the answer to Missouri’s growing waterhemp problem. A prolific producer of seeds, waterhemp is Missouri’s main weed problem and one of 14 weeds that are herbicide-resistant.

Two brothers in Illinois with backgrounds in farming and engineering designed The Weed Zapper machine. Other two siblings purchased the technology and manufacture Weed Zappers at a plant in Sedalia, Missouri.

“The Weed Zapper model used in MU research has a copper boom that attaches to the front of a tractor. Driven by a PTO, it hits weeds with 15,000 volts of electricity from a 110,000-watt generator on the back of the tractor. Models cost between USD42,000 and USD72,000”, wrote the MU experts.

“Weed Kill is Best at Lower Speeds”

Metal wheels are grounded, and booms adjust to different heights. Tractor speed is about 2-4 miles per hour, Bradley says. Weed kill is best at lower speeds and is even more effective on some of the more challenging weeds when used at seven-day intervals in late summer.

Schreier’s data shows that by the end of the season there is almost complete control of giant ragweed, common ragweed, marestail and waterhemp. It is slightly less effective on grasses.

In addition to killing weeds, electrocution also affects viability of surviving weed seeds. The most impact is seen in waterhemp, where about 65% of seeds become nonviable.

Electrocution is not new to the weed management world, says Bradley. Sugar beet growers in North and South Dakota have been trying this method since the 1950s and 1960s.