CANOLA (BRASSICA NAPUS) COMPETITION FOR WEED MANAGEMENT

Canola (Brassica napus) is an important break crop in the temperate cropping zone of southern Australia. Although a wide range of herbicide-tolerant cultivars are now available, weeds can still significantly reduce grain yield and quality. Crop competition is a useful tool for reducing weed impacts and suppressing weed growth and spread. A field experiment in 2009 studied the impact of two canola genotypes and four crop densities on the competitive ability of canola with wheat, an important volunteer weed in canola. Significant effects of competition on the suppression of the weed and grain yield were recorded. Manipulation of crop agronomy by choice of genotype and increasing crop density to reduce weed impacts is a cost-effective and simple way for famers to improve weed control, increase herbicide efficacy and prolong the life of useful chemicals by reducing the rate of development of herbicide resistance.