Agriculture Victoria is urging Wimmera grain growers to test weeds for herbicide resistance in an effort to save money as well as improve weed control.
The agency co-ordinated three workshops earlier this year where herbicide resistance expert Peter Boutsalis from the University of Adelaide spoke to more than 70 growers.
Dr Boutsalis said while herbicides sometimes failed to fully control weeds for a variety of reasons, growers should avoid assuming it was due to resistance.
He said two tests were available to determine if resistance was the issue.