Take home messages

• Herbicide Mode of Action (MoA) classifications will be updated to align with the new globally aligned system.
• The science hasn’t changed – just the classification codes on product labels and literature will change from a letter to a number.
• Continue to follow current integrated weed management strategies and rotation plans.
• More information will be provided to growers and advisers throughout 2021.
• Growers can expect to start seeing herbicide labels with the new mode of action classification system from early 2022.

Background

Farming is becoming increasingly global. Farmers, agronomists and academics around the world are now, more than ever, sharing and accessing information to assist them to grow crops, while managing sustainability issues such as herbicide resistant weeds.

It’s important then that the herbicide MoA classification system used in Australia be aligned with the global classification system to ensure Australian farmers and advisers can access the most up-to-date information relating to managing herbicide resistance.

Discussion

Herbicide Mode of Action (MoA) classifications have been updated internationally to capture new active constituents and ensure the MoA classification system is globally relevant.

The global MoA classification system is based on numerical codes which provides infinite capacity to accommodate new herbicide MoA coming to market, unlike the alphabetical codes currently used in Australia.

CropLife is working with key herbicide resistance management experts, advisers, GRDC and the Australian Pesticides and Veterinary Medicines Authority (APVMA) to ensure farmers and agronomists are aware of the planned changes.

Farmers can expect to start seeing herbicide labels with the new mode of action classification system from early 2022. There will be a transition period during which herbicide labels will exist in the supply chain, some bearing the legacy alphabetical MoA classifications, and others transitioned to the global numerical system.

The numerical classification system should be fully implemented by the end of 2024.

A mobile app compatible with Android and Apple systems is available via the HRAC website at no cost to users. It will cross reference the herbicide active ingredient with its former MoA letter and new MoA number. Printed materials will also be made available to enable cross referencing of the changes.

Conclusion

CropLife is working with industry experts to identify the consequences of these changes regarding how products fit into an integrated weed management (IWM) program and will provide more specific guidance on the changes in mid-2021.

The way growers use herbicides in the field will not change. The science hasn’t changed and the mix and rotate messages remain correct. It is just the classification codes used on product labels and literature that will change from a letter to a number. Growers are advised to continue to follow their current IWM strategy and rotation plans.

Acknowledgements

This project is made possible by the significant contributions of CropLife members and the herbicide mode of action alignment advisory group.

Useful resources

CropLife Australia resistance management

Global classification lookup app available for download

Glyphosate fact sheet

Contact details

Dr Katie Asplin
Director – Science and Stewardship Policy (Chemistry)
CropLife Australia
02 6273 2733; 0420 874 865
katie.asplin@croplife.org.au