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Herbicide resistance rampant in Australia

In Australia, herbicide resistance is an industry-wide problem that needs solutions

Western Australia’s farmers are fighting herbicide resistant weeds by doing everything from burning windrows to using chaff carts.

But what works in one state doesn’t necessarily translate to another.

John Midwood, CEO of Southern Farming Systems.

John Midwood, CEO of Southern Farming Systems.
photo: Lisa Guenther

In the state of Victoria, the longer growing season means much of the annual ryegrass has fallen into the base of the crop by harvest, says Jon Midwood, CEO of Southern Farming Systems. “So it doesn’t really matter what you have behind the header (combine). If you can’t capture it up the front, you get no control.”

Southern Farming Systems is a non-profit research group in Australia’s high rainfall zone. Its researchers are looking at how harvest weed seed destruction might work in Victoria. They’ll study variables such as cutting height and crop type — for example, looking at whether weed seed destruction works better in barley because it ripens earlier, Midwood explains.

Southern Farming Systems, it turns out, is one spoke in a national research hub that’s tracking the spread of resistant weeds and finding ways to manage them.

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Seeding near the Goyder Line, Peterborough, South Australia.


Weed surveys

Right now, the University of Western Australia surveys resistant weeds annually. And the University of Adelaide also surveys herbicide resistant weeds.

“You can go online any hour of the day and find out how many paddocks (have) resistance around Australia,” says Lloyd O’Connell, who edits several farm magazines in Australia, including Australian Grain.

Those weed surveys have “enormous value,” says Brad Collis, editor of Ground Cover, a magazine published by Australia’s Grains Research and Development Corporation (GRDC). The surveys show herbicide resistance is an industry-wide problem, rather than singling out any one farmer, he adds. And the surveys allow farmers to draw on each other’s experiences, he says, as they can see when other regions have dealt with resistance to a specific herbicide years ago.

Ultimately, the surveys’ value can be summed up in that old saying: “You’ve got to know the problem before you can solve it,” says O’Connell.

Big picture, local solutions

The GRDC collects a compulsory levy from every tonne of grain sold, Collis explains. That levy, along with government money, make up the bulk of GRDC’s funding. The organization also collaborates with multinationals, Collis adds. The GRDC then invests in ag research projects.

This gives Australia an overarching national research structure, with very strong regional hubs, such as Southern Farming Systems, O’Connell says. It’s within the regional hubs that they’re able to identify emerging issues or research needs, he adds.

A few years ago, farmers were very worried about herbicide resistance, as there were no new chemical options in the pipeline, Collis says.

“But once people realized that there were options, and once the research began to articulate those options and slightly more sophisticated management practices, people picked them up fairly quickly,” he says.

Back at Southern Farming System’s Inverleigh site, Midwood lists some of the options Victoria’s farmers have to manage resistance. Mixed farms can rotate really bad paddocks back into pasture, he says. They’re encouraging farmers to keep seeding rates high and to seed based on seed weight, he adds. Narrow rows encourage crop competition. Burning is a fantastic tool, he says.

Farmers still have some herbicides, said Midwood. “It’s all about stacking everything up at the front end of the season because we’ve got no armory left post-emergent.”

Southern Farming Systems also finds some practices that are counterproductive to herbicide resistance. For example, they’ve also done a lot of work showing improved yield and margins with earlier sowing dates, says Midwood. “But actually that’s creating issues also with the ryegrass.”

Getting the word out

Researchers have also played a key role in communicating information about herbicide resistance.

“I think once that information started coming through, there was acceptance that there was a pretty serious issue and it wasn’t just one particular weed developing it — that it was a range and management practices have certainly contributed to that,” says Ben White, editor of Farming Ahead.

Midwood says they focus on educating advisers and retailers because they’re the conduit to growers. GRDC’s work tends to be project-based, and there aren’t instant answers, Midwood says. But once they “get wings on stuff and stories to tell, that gets put back to growers and advisers,” he adds.

Ground Cover, GRDC’s magazine, is one means of doing that. Science and on-farm practices differ significantly from one side of the country to the other, says Collis. Ground Cover provides a forum for farmers to share those experiences, he adds.

Ian Paterson, editor of Rural Business, says there’s been a lot of effort to educate people about herbicide resistance over the last 10 years. Each year Rural Business runs six to eight stories on herbicide resistance, plus a special feature every September.

“We get more editorial and advertising for that particular feature in September than we do in any of the other special features that we run,” he says.

Troy Missen, who farms in Western Victoria, says he keeps informed through farmer groups and his agronomist. But lately he’s found Twitter useful, especially since he’s short on time.

“I’ll have a quick flick and I read a lot of the GRDC stuff,” says Missen.

No one seems too down-in-the-mouth about herbicide resistance. White says farmers are optimists by nature and will find ways to adapt different technologies or practices wherever required. Even weedy properties can be cleaned up by a good operator in two or three years, he said.

Midwood moved from the United Kingdom to Australia 11 years ago. In that time, he’s seen Australian farmers pick up different cultural controls and use herbicides more effectively. Managing herbicide resistance is “an ongoing battle,” he says.

“We get a few wins and we get a few losses,” he says.

About the author

Field Editor

Lisa Guenther

Lisa Guenther is field editor for Grainews based at Livelong, Sask. You can follow her on Twitter @LtoG.

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