High frequency electricity has been shown to give better weed control and with lower energy use, according to a Warwickshire-based company the makes a leccie weeder.

Independent trials of RootWave’s tractor-mounted Volta machine in maize and sugar beet crops showed full control of weeds, it said. Meanwhile, in-house tests showed that its patented high-frequency weed control used just a fifth of the energy verses herbicides, on a per hectare basis. V

olta compares even better against other alternative weed control methods, meaning it offers a unique combination of high control and low energy use. Such has been the success, that the weed control pioneers plan to release a commercial version of Volta in the UK and Europe for fruit crops and broad acre row crops in the coming years.

Chief executive officer, Andrew Diprose, said: “In independent tests Volta provides better weed control in fewer treatments with no impact on crop or soil. We have a system that can provide low-cost weed control that helps nature restore biodiversity.

“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.”

Trials conducted in commercial maize and sugar beet crops in Warwickshire and Norfolk, this summer, confirmed that the machine delivered up to 100% control, averaged 99% control across one sugar beet trial site, and outperformed herbicides in all cases (see graph 1).

In equivalent herbicides trials, products must deliver 85% control to be able to claim weeds as ‘susceptible’ on the label. In all trials over the summer, Volta bettered the control delivered by herbicides – in one case by over 60 percentage points, said Mr Diprose.

RootWave’s Volta is powered by a traditional diesel tractor, with a 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.

In the company’s own tests, effective weed control was delivered from just 50 megajoules (MJ) of energy per ha (recorded range 50-98MJ/ha) – by comparison, herbicides can use more than 500MJ/ha, when taking into account the production and distribution of the chemicals. Other alternative weed control methods range from 800MJ/ha to more than 8000MJ.

The company has patented the use of high frequency electricity at over 18 kilohertz (kHz) for weed control on the grounds that it is fundamentally safer than DC, or standard 50 hertz (Hz). RootWave launched its award-winning handheld weeder, RootWave Pro, in 2017 and has sold nearly 150 units across Europe – moving up in scale, the Volta will be released for fruit and broad acre row crops in the next few years.