Economic evaluation of a weed-activated sprayer for herbicide application to patchy weed populations

Spatial distribution of weeds in a crop is patchy. Traditional boom sprayer s waste herbicide by applying it to areas where weed density is already low . A new technology, Weed Activated Spray Process (WASP), uses sensors to de tect the presence of weeds and control spray nozzles accordingly. The econo mic benefits of this technology to extensive crop farmers in Western Austra lia are investigated using a model based on the economics of information. E xisting technology is likely to reduce profits because the weed density at which it switches off spraying is too high. Even if sensitivity to low dens ities could be improved, likely benefits of pre-crop usage would still be v ery low or negative.