Two new broad-spectrum herbicide options are moving through regulatory pipelines, with Bayer and Nufarm each advancing separate active ingredients for grain growers.

If approved by the Australian Pesticides and Veterinary Medicines Authority, the new knockdown options could be available to farmers by 2028.

Bayer Australia has lodged an application for icafolin-methyl, the first herbicide from a new isoxazoline carboxamide chemical class. Bayer’s head of crop protection for Australia and New Zealand, Tony May, said herbicide resistance was a growing challenge for Australian growers.

Earlier this year, Nufarm confirmed a partnership with Chinese agri-biotech company KingAgroot to develop flufenoximacil (FFO), a broad-spectrum, non-selective knockdown herbicide. Grain Producers Australia research, development and extension spokesman and Rupanyup farmer Andrew Weidemann said grower demand for new chemistry was strong and more options were needed.

“Products that have a similar characteristic to glyphosate or paraquat are used on virtually every Australian farm,” he said. “We need something to rotate chemistries with to avoid resistance and to put another tool in the toolbox and these products are coming in the nick of time.”

Mr Weidemann said pricing and availability would ultimately determine uptake and there was still a little way to go before they were commercially available. In June, the APVMA’s finalised its review of the controversial weedkiller paraquat, permitting its ongoing use in Australia under stricter regulations.

But earlier this month, manufacturer Syngenta announced it was withdrawing from the Australian market and ending all global production of the chemical.

Mr Weidemann said this highlighted the need for more herbicide options for farmers.

Wilkur and Berriwillock farmer Craig Henderson welcomed the new chemistry options but called for the approvals process to keep pace with on-farm need.

According to APVMA records, newer herbicide actives have entered the Australian market in recent years, including tiafenacil in 2020.