It is a device designed to distinguish plants from agricultural soil (soil background); of the type that a photographic camera uses to proceed with the capture of images and process them in order to perform the detection of weeds, and from it, with the information obtained, to drive an actuator that controls the operation of corresponding media valves that command the work of the sprinklers arranged in the carrier boom of the sprayer, through which it is possible to apply herbicidal products, or exercise a control over them that may be mechanical or chemical.