The Weed-Suppressive Ability of Summer Cover Crops in the Northern Grains Region of Australia

Pressure is mounting on the agricultural sector to reduce reliance on herbicides for weed control leading to increased interest in the potential of cover crops to control weeds in summer fallows. The weed suppression ability of three summer cover crop species, buckwheat, millet and teff, was evaluated in field trials at two sites near Camden, NSW in 2021. Buckwheat, millet and teff reduced weed biomass by 65%, 77% and 95%, respectively at Bringelly and by 94%, 92% and 90%, respectively at Lansdowne. Following cover crop desiccation, teff residues reduced weed emergence in subsequently planted wheat by 73% and 26% at Bringelly and Lansdowne, respectively. Overall cover crops were found to be effective in suppressing weed emergence, growth, and reproductive capacity. These studies identified teff grass as an important summer crop option for the northern grains region.