Disclosed is a control system (28) for stopping or reversing movement of an irrigation system that traverses the ground on wheels. The control system (28) comprises an electronic proximity sensor (30) and a control device (32). The electronic proximity sensor (30) is mounted to the irrigation system and operable to detect a target placed on or in the ground. The control device (32) is responsive to the electronic proximity sensor (30) for stopping or reversing movement of the irrigation system when the electronic proximity sensor (30) detects the target.