To compare the competitive nature of wheat and barley sown at different row spacing and seeding rates on grass weed competition.

Increased use of grass selective herbicides in many farming systems has caused increased selection pressure for herbicide resistance in grass weed populations such as annual ryegrass and brome grass. Work conducted by Bill Roy (Agricultural Consulting & Research Services Pty Ltd, York) with GRDC support demonstrates that managing herbicide resistance requires a diversified approach using a number of different tools. Manipulating canopy through seeding rates and row spacing is one of the options being explored by the BCG.