Pushing back on herbicide resistance

WeedSmart southern extension agronomist Chris Davey says that many on the eastern Eyre Peninsula observed annual ryegrass that had started to germinate earlier than usual after a very wet January in 2022.

“Early germination led to further exposure of ryegrass to glyphosate from the summer weed herbicide mixes, which added large quantities of glyphosate-resistant annual ryegrass seed to the seedbank,” he says. “This is a significant challenge to the wheat–RR-canola rotation that has long been a mainstay cropping system in the region, particularly on the Lower Eyre Peninsula. This will be one of the key discussion topics at WeedSmart Week in Port Lincoln this July.”

For more than a decade, WeedSmart has promoted science-backed weed management tactics proven to work in the field to drive down weed numbers and reduce the impact of herbicide resistance in dryland and irrigated cropping systems.

Project manager Lisa Mayer says the WeedSmart Week event, planned for Port Lincoln on 29 and 30 July, promises to deliver practical solutions to the weed management challenges facing growers on the Eyre Peninsula.

“The two-day event will delve into ways to mix and rotate herbicides within a diverse cropping rotation to address evolving herbicide resistance,” she says. “Local agronomists and growers will speak about how they are disrupting weed cycles and using mechanical and cultural practices to underpin their herbicide programs to drive down the weed seed bank in crop and in the fallow.”

Chris says the plan is to ‘kick around’ some constructive ideas that growers can implement, such as double breaks and increased herbicide diversity, summer weed control strategies, increasing crop competition through soil amelioration and overcoming the challenges associated with adding lentils to the rotation.

“Hearing directly from growers in the region, both at the forum and on the farm visits, is such a valuable way to gain new ideas and adapt them to your farming system,” he says. “We often hear from people who have attended previous WeedSmart Week events and returned home to immediately implement something they have learned at the event.”

WeedSmart Week begins with the forum day at the Nautilus Arts Centre, Port Lincoln, on Monday, 29 July. This two-day event includes a bus tour to farms in the region and a machinery expo on Tuesday, 30 July.

“Kondinin Group’s research manager, Ben White, will host the machinery expo at Jordan Wilksch’s farm, featuring the latest in spray and camera technology, impact mills and other mechanical weed control tools used on Eyre Peninsula farms,” says Lisa. “The farm visits and machinery expo are always a highlight of the event as forward-thinking growers outline how they implement the WeedSmart Big 6 tactics in their farming system.”

The flagship annual event attracts growers, farm workers, agronomists and students from all mainland states, highlighting the practical nature of the event. The broad cross-section of growers responded to the opportunity to engage with WeedSmart’s industry sponsors, who showcased their weed management tools at the forum and the machinery expo.

Check the full program and register for this important two-day event for the ‘early bird’ single ticket price of $270 (GST incl). This includes the bus tour, machinery expo and forum, all fully catered. Early bird pricing is available until 28 June 2024. Group bookings and student discounts are also available.

Lisa says early implementation of the herbicide and non-herbicide tactics that form the WeedSmart Big 6 effectively minimises the impact of herbicide resistance on farm profitability.

“This will be the eleventh WeedSmart Week event and is made possible through the support of the GRDC as the major sponsor and a wide range of herbicide and machinery companies – all with skin in the weed control game,” she says. “Growers and advisors from other areas are encouraged to take advantage of GRDC’s financial support for study tours to attend events such as WeedSmart Week.”

The Grains Research and Development Corporation (GRDC) is a platinum supporter of WeedSmart. This investment ensures growers can access world-class research outcomes and strategies to mitigate weeds and control herbicide resistance.