Independent trials of a tractor-mounted electric weeding machine in maize and sugar beet crops have shown that the system can give full control of weeds.

The Warwickshire-based weed control pioneer Rootwave is developing a chemical-free approach based on electricity, which is hoped to be available for broad-acre row crops in the coming years.

See also: How Yorkshire grower reduced risk with regenerative system

This season saw the experimental system undergo independent testing in commercial maize and sugar beet crops in Warwickshire and Norfolk.

Rootwave chief executive officer Andrew Diprose says the independent tests showed that the system provides better weed control in fewer treatments, with no impact on crop or soil.

“Electricity provides full control of weeds by boiling them from the root upwards. This is an advantage over other alternative methods that cut or burn the weed above the surface, leaving the roots.”

The machine delivered up to 100% control, averaged 99% control across one sugar beet trial site, and outperformed herbicides in all cases (see graph below). 

How it works

The Volta machine is powered by a traditional diesel tractor, with the generator running from the front pto.

The technology is also compatible with green-energy sources and autonomous systems, such as driverless tractors and carbon-free fuels.

Rootwave has patented the use of high-frequency electricity at more than 18kHz for weed control.

Finally, the company’s own tests show that effective weed control was delivered from just 50MJ/ha of energy.

According to Rootwave, this compares with more than 500MJ/ha for herbicides, when taking into account the production and distribution of the chemicals.

Other alternative weed control methods range from 800-8000MJ/ha.