Controlling weeds in arable crops using electricity is a step closer with the first commercial tractor-mounted units destined for specialist crop growers in the UK.

Better known for its precision-guided mechanical weeders, visitors to Groundswell (2-3 July) in Hertfordshire saw Garford’s 3m Toolbar incorporating technology developed by Rootwave.

See also: Grower phases out herbicides in favour of mechanical weeding

Making its debut at the event, the system uses electricity to boil weeds and their roots.

Garford managing director Jonathan Henry explained that it works by passing current through the plant, which heats the fluid in the plant cells, vaporises them and that damages the plant cells.

“After that happens, the plant dries out, desiccates and dies,” he said.

A power take-off driven generator creates high-frequency AC power that is fed down to a pair of electrodes, one following the other.

Electricity passes from one to the other through the soil.

“If you use the soil as the return conductor, you can destroy the root as well and thereby achieve a systemic treatment,” Jonathan said.

Two 3m units have been built so far and are destined for high-value crops such as organic carrots.

Speaking to Farmers Weekly, Andy Baggott, UK sales manager at Garford, explained that the carrot beds are formed and plastic film placed on top to warm the soil and encourage weeds.

Then the plastic is removed and weeds are burned off using gas burners prior to planting.

© MAG/Richard Allison

The farmers see the electric system replacing the burners, which will pay for themselves within two years.

Looking ahead, Garford sees the technology being used in arable, broad-acre crops.

It plans to use two generators to enable a 6m model, which would be more practical for arable crops.

Jonathan said the technology is proven, and because it is non-chemical and does not disturb the soil, it is compatible with both organic and regenerative farming systems.

However, he acknowledged that the challenge is the economics and how it fits in with existing farming systems.

“Arable farms are run pretty lean and the key challenge is integrating it within existing systems and labour.”