Effect of wheat seeding rate on wild oat competition

Abstract

A series of field trials was sown on black earth soils on the Darling Downs, Queensland, with five wheat seeding rates x five levels of wild oat infestation. The lowest seeding rate required to produce optimum grain yield at a site was higher in wild oat infested plots than in weed-free plots. Increase in seeding rate reduced the dry weight of wild oats at maturity and increased the dry weight of wheat at maturity until wheat population density exceeded 150 plants m-2. Increase in seeding rate also reduced wild oat seed production, especially at low wild oat population densities.