Flaxleaf fleabane, which is increasingly an issue for Western Australian grain growers, is difficult to kill, particularly when mature, and its germination is favoured by factors including good spring rainfall.
However, if growers use a range of control tactics and monitor paddocks vigilantly, successful control is possible.
Grains Research and Development Corporation (GRDC) plant health technologies program manager Ken Young said research showed that optimum control came from targeting young, small fleabane (seedlings and young rosettes) as herbicide efficacy decreased as the weed matured.
“A double-knock approach is needed for dense infestations, especially if weeds are more than one month old,” he said.
“To reduce the likelihood of resistance developing, use full label rates of herbicides, rotate herbicide groups and prevent seed set of survivors.”
Information about managing fleabane is available in the GRDC Flaxleaf Fleabane Fact Sheet, and was included in the September/October edition of the GRDC magazine Ground Cover.