Canola Competition for weed suppression

Abstract

Summary: Competitive crops are an important component of integrated weed management systems to reduce dependence on herbicides and resistance spread. Canola (Brassica napus) is a useful break crop but its potential to suppress weeds such as annual ryegrass (Lolium rigidum) has not been quantified in Australia. A study was conducted in 2009 to examine the range in competiveness available in 15 current canola types with annual ryegrass. Significant differences in grain yield of canola were recorded in weedy and weed-free plots, with percentage yield reductions from weeds of 60'100%. Crop competiveness was also assessed by weed dry matter suppression at flowering, which was negatively correlated with crop dry matter. The hybrids were higher yielding and were more competitive than the triazine'tolerant cultivars