A post-harvest spray will be an important control measure for paddocks with high populations of fleabane and sow thistle this summer. Ahead of what is expected to be a bumper harvest, growers and agronomists were urged to plan their summer weed in mid-October. The event was also attended by seven weed management researchers from Charles Sturt University who were visiting BCG.
“They (fleabane and sowthistle) can hurt you after harvest” said BCG’s Senior Research Agronomist, Angus Butterfield, who is leading the GRDC National Grower Network funded research.
“These weeds are difficult to control, particularly fleabane once it starts elongating. If you notice weeds in the paddock now, think about a knockdown soon after harvest with a brew featuring a group 4 herbicide. Following up with a double knock is essential for good control” adding growers should aim to get this done before Christmas as weed size and spray conditions may make control challenging in the new year.
Attendees inspected the wheat and lentil trials where various herbicides, application timings and sowing rates for crop competition are being utilised to assess fleabane and sow thistle control. They discussed the growth habit of fleabane learning that it has germinated all year, due to warmer average temperatures in 2026, however with thick crop canopies, they have been harder to detect and therefore summer weed control in problem paddocks was considered essential.
Growers were particularly interested in the lentil trials for sow thistle control. In paddock-scale situations, it is a challenge to balance crop safety (herbicide damage) with effective weed control. The relatively new lentil variety, GIA Metro , is part of the trial and is considered an effective option because of its imi-tolerance. “This option offers the best weed control by far” Mr Butterfield said. “However the variety is lower yielding than NVT averages by 30 per cent which isn’t a profitable proposition at present”.
Attendees reported the day increased their understanding of the management options available leading into summer. “Fleabane control is very topical in the region” said local farmer, Bill Lee, “it was great to hear the discussion and have this important research in my own backyard…. I’m looking forward to hearing more”.
Angus will be presenting results from this research at the members-only BCG’s Trials Review Day, Friday 19 February, 2027. Results will also be published in the 2026 BCG Season Research Results compendium that will be released on the same day.
“Summer weeds fleabane and sow thistle management demonstrations for the Victorian Mallee” is funded by GRDC via the National Grower Network (NGN) scheme. (BWD2504-002SAX).
