Killer farm robot dispatches weeds with electric bolts

In a sunny field in Hampshire, a killer robot is on the prowl. Once its artificial intelligence engine has locked on to its target, a black electrode descends and delivers an 8,000-volt blast. A crackle, a puff of smoke, and the target is dead – a weed, boiled alive from the inside. It is part of a fourth agricultural revolution, its makers say, bringing automation and big data into farming to produce more while harming the environment less. Pressure to cut pesticide use and increasing resistance to the chemicals meant killing weeds was the top priority for the farmers advising the robot company.