REFILE - ADDING PICTURE TAKEN  The prototype of an autonomous weeding machine by Swiss start-up ecoRobotix is pictured during tests on a sugar beet field near Bavois, Switzerland May 18, 2018. Picture taken May 18, 2018. REUTERS/Denis Balibouse
The prototype of an autonomous weeding machine by Swiss start-up ecoRobotix. AI and automation is set to disrupt the global pesticides market. Denis Balibouse/Reuters

Robot farmers use precision attacks in war on weeds