SLOWLY BUT surely, a spidery machine about the size of a golf cart swings an electrode over a tray of plants. Every few seconds there is a small puff of smoke as a weed keels over, having been zapped with a high voltage. The device doing the zapping is a prototype weeding robot developed by the Small Robot Company, a new firm operating out of an old munitions depot near Salisbury, in south-west Britain.
Such machines, called “agribots”, are appearing in many shapes and sizes from a variety of companies. Muddy tracks from other prototypes lead into the Small Robot Company’s workshop, where a row of 3D printers make bright orange components out of plastic. That makes parts easier to find should they fall off in a field, which is a sure sign that farmers are at work here, with roboticists and scientists.
Weed control is essential for improving crop yields, but it is getting increasingly difficult. Some weeds are becoming resistant to herbicides, which face stricter regulation and in some cases are being banned. On top of that, many consumers want organic produce. And labour shortages mean that repeatedly tilling the soil to disrupt weed growth using a mechanical hoe towed behind a tractor is costly, time consuming and not always practical.
Weeding is a chore that most farmers would happily hand to robots. But for a...