Diversity disrupts evolution: The future of global weed management

With a declining amount of chemical innovation in the weed management industry, it is expected a mix of technology, farming practices, and herbicides will be the keys to the future of weed management.

Diversification was the message at the 20th Australasian Weeds Conference in Perth this week, with growers facing increasing weed resistance to herbicides, and an industry that has not been able to keep up.

There has been a decrease in patent filings and product launches, and no new modes of action for over 20 years in the herbicide industry — but this does not discourage head of weed control research for Bayer Crop Science, Dr Marco Busch.

"I'm really excited about the opportunities," Dr Busch said.

"If you identify the issue, you can do something about it."

And for Bayer Crop Science, that means the development of new products — a process which can take up to 10 years.

So what can be done to tackle herbicide resistance in the meantime, and for the future?

Diversification

"Herbicides are not the only tool the farmers have at their hand, there are all those agronomical tools," Dr Busch said.

With technology advancing, new tactics are required to provide longevity to the current and future herbicides on the market.

General manager of crop protection for the Grains Research and Development Corporation, Dr Ken Young, believes the Australian grains industry is "at the beginning of a new dawn" where growers are becoming more receptive to incorporating new tactics into their farm plan.

"That can be crop cultivation, through to cultural management through row spacing, row orientation, through to the new technologies that are coming through where they can use microwaves or targeted tillage to control their weeds," Dr Young said.

Dr Young believed the increasing cost of weed management in the Australian grains industry was the catalyst for this "new dawn".

"In the past, herbicides have worked extremely well, and been very cost effective, very cheap relatively," he said.

"And it's only until that system's not working we have to look for other answers, and that's what the case is."

Earlier this year the GRDC commissioned a report into the cost of weeds, and found there had been a "huge increase of the costs of managing resistant weeds", to $3.3 billion annually in expenditure and yield loss, costing Australian grain growers an average of $146 per hectare.
"Growers look at that additional cost and say 'what else can I use to manage that? And if I've got to pay an extra $60 a hectare to manage my weeds, what can I use that $60 for? Is it best of using a herbicide? Or is it best of using harvest weed seed management to do it, and getting longevity of my herbicides as well?'," Dr Young said.

Australian innovations competing internationally

Compared to overseas counterparts, Australia is thought to shape up relatively well when it comes to innovation in weed management.

Director of the Australian Herbicide Resistance Initiative (AHRI), Professor Stephen Powles, believes this comes down to necessity: where there are issues, there is innovation.

"We've had to be [leaders], because of the massive herbicide resistance problems we've had," Professor Powles said.

"And as a result, we've developed some technologies in Australia that have not been developed elsewhere.

"Especially what we call 'harvest weed seed control' (HWSC)."

Professor Powles said most Western Australian farmers were using a form of HWSC, which targeted weed seeds during harvest to minimise the seed bank.

"We all should be proud of that work that's been home grown Australian research," he said.

"Our agronomists are very good, our farmers are very, very good, our farmers are excellent farmers, so we've got a lot to be proud of in the area."

However despite home-grown developments such as HWSC, Professor Powles believes Australia will remain reliant on technology developed overseas.

"The herbicides that are used here are not developed here, they're developed by the small number of corporations because of the huge research effort that's required," he said.

"It's a combination of international technology and how to make it work in Australia."