Integration of seed and plant kill tactics for control of wild oats: An economic evaluation

Abstract

A major grass weed of winter cereals, wild oats ( Avena spp.), is primarily controlled by killing plants, either prior to sowing a crop or within the crop. The economic feasibility of seed kill for controlling wild oats in wheat is evaluated using a dynamic programming model linked to a bioeconomic simulation model. In the context of Australian wheat crops, the tactic of killing wild oat seeds was found to be economically viable under some conditions when combined with existing weed management practices. From this, it is suggested that it would be prudent to divert some research funds into developing this tactic. The two critical parameters which determine the viability of the seed kill option are the effectiveness of the control agent in killing seeds and the cost of the treatment. Assuming 60% seed kill as the upper limit, seed kill is economically feasible only if it costs less than (Australian) $12/ha per year. When seed kill is economically feasible, the profits increase due to initial yield advantages caused by rapid depletion in seed reserves as well as by overall savings in herbicide cost. The analysis indicated that the savings in herbicide usage could be as high as 65%. Indirect benefits from such drastic reduction in herbicide usage, although not evaluated in this study, could also be realised.