Glyphosate resistant barnyard grass in Western Australia’s top end

With the recent discovery of WA’s first glyphosate-resistant awnless barnyard grass from the Ord River region growers are being urged to consider using a range of weed control options.

Agronomist Andrew Cripps from the Ord River District Co-operative Ltd (ORDCO) identified suspect populations and contacted the Australian Herbicide Resistance Initiative (AHRI) for assistance in confirming resistance.

Research associate Dr Todd Gaines from AHRI based at The University of Western Australia (UWA) visited Kununurra and has now shown that several populations of awnless barnyard grass (Echinochloa colona) are glyphosate-resistant.

"We confirmed populations from two paddocks that are 8-fold more resistant than susceptible populations collected in the region. The good news is that these populations are controlled by Group A and B herbicides, as well as paraquat and glufosinate.” Dr Gaines said.

Agronomist Andrew Cripps who has been working in the Ord River region for several years explains “The Ord River region is home to diverse cropping systems in a tropical environment, with horticulture, tree and grain crops being the major crops grown. Glyphosate is relied upon heavily for weed control in this area and growers need to start implementing a range of weed control tactics in order to sustain the life of glyphosate in the Ord.”

AHRI Director Professor Stephen Powles stated “Future AHRI research will involve investigating the resistance mechanism in these populations, as well as providing recommendations to Ord River region farmers about how to manage and minimize the evolution of glyphosate resistance in barnyard grass.”

Professor Powles stated “There are several glyphosate-resistant barnyard grass populations in Queensland and New South Wales. It’s important for all industries who use glyphosate for weed control to understand and recognise that glyphosate resistance can and will evolve. To combat resistance, diversity in weed control tactics is essential to help minimize resistance evolution.”

Source: AHRI