The cost of wild oats (Avena spp.) in Australian wheat production

The cost of uncontrolled Avena spp. (Avena fatua and A. sterilis), through yield losses and dockages for contaminated wheat, and the cost of control methods, is reviewed, using gross margins analysis. In competition and herbicide trials in Australia, grain yield losses due to Avena spp. range from nil to 75%. A yield of 2500 kg/ha gave a yield loss of 35% resulting in a gross margins loss of 50%. The importance of using high cost herbicides correctly is shown; if diclofop-methyl and flampropmethyl are applied incorrectly or too late so that, instead of a maximum yield increase, there is no yield increase, the gross margin is reduced from $115 to $44/ha. Avena spp. control by rotating winter and summer crops in Queensland is achieved at no cost. The significant points demonstrated in this review are applicable in many crop/weed situations