Bayer, UWA collaborate to combat metabolic resistant ryegrass

On the heels of its A$45 million partnership with the Grains Research and Development Corporation (GRDC) to develop weed control solutions for farmers, Bayer CropScience has announced it is joining forces with The University of Western Australia (UWA) to combat herbicide resistant annual ryegrass.

Together with funding from the Australian Research Council, the three-year, A$1.1 million initiative will involve research conducted by the Australian Herbicide Resistance Initiative (AHRI) based at UWA and supported by GRDC, linked with researchers at the Weed Resistance Competency Centre (WRCC) of Bayer CropScience in Frankfurt, Germany.

The project will specifically target metabolism-based herbicide resistance in annual ryegrass, which forms a significant portion of the herbicide resistance profile.

“In some cases it is easy to determine how plants evolve resistance, while in other cases it’s not. One of the most difficult nuts to crack is how ryegrass biochemically breaks down or metabolises herbicides,’’ said AHRI Director and UWA Professor Stephen Powles.

“It’s a major threat because if ryegrass breaks down herbicide modes of action that have not been discovered yet, we have problems. This is a very scary resistance mechanism.’’

The project will identify genes responsible for metabolic resistance and seek to inhibit them.

“This can help design new molecules that the genes cannot break down, as well as other ways to inhibit them,’’ Professor Powles said.

“Working with Bayer CropScience in Germany, we have already identified some genes responsible and are looking at inhibiting them. This process takes time and it requires sophisticated techniques; it is a win-win collaboration.”

In addition to the GRDC partnership, this latest project demonstrates Bayer CropScience’s strong commitment to weed control research and developing solutions for farmers worldwide.

In a presentation at UWA on June 4, Dr Hermann Stuebler, Head of Weed Control Research with Bayer CropScience in Frankfurt, Germany, said the research would look to develop new strategies for combating metabolic resistance in ryegrass and this would be integrated into the company’s wider resistance research program.

“We are extremely excited to announce this second resistance fighting initiative in one week, following the announcement of the Herbicide Innovation Partnership with GRDC,” Dr Stuebler said.

“Weed resistance is a rapidly growing problem across the agricultural world, affecting many crops and many different chemical classes.

“Annual ryegrass is one of the key weeds in broadacre crop production in Australia and worldwide. It is of particular concern that it has evolved simultaneous resistance against various herbicide classes, limiting weed control options for farmers. This has been due to the degradation of the herbicides caused by the metabolic resistance phenomenon.”

He said the project with AHRI aimed to understand this mechanism and its genetic background in order to develop diagnostic tools, create control strategies and assist the discovery of new herbicide classes that overcome multi-resistance.

“Bayer CropScience is eager to utilise these findings to provide Australian and world growers with new, highly effective options to manage weed resistance.”

It is estimated Australian farmers lose more than A$3 billion a year due to resistant and poorly controlled weeds.

Professor Powles said every serious grain grower knows herbicide resistance is a major cost to their business.

“In Western Australia, a 500-paddock survey indicated that 95 per cent of the ryegrass populations randomly collected across the wheatbelt is resistant to common herbicides.’’

“Due to resistance, growers have had to do things differently and use different things – and this has cost them money. It is a pain in the back pocket,” he said.