6 September 2024
Paraquat and diquat agrochemicals have been used in Australia since the mid 1960’s as non-selective contact herbicides and plant tissue desiccants. Current use of these actives in vineyards is for post-emergent weed control, as part of a toolkit including other actives such as glyphosate and glufosinate-ammonium.
The Australian Pesticides and Veterinary Medicines Authority (APVMA) has recently completed a Technical Review of paraquat and diquat, in the areas of: (a) toxicology of both the active constituents and products, (b) worker health and safety, (c) residues and trade assessment, (d) environment safety including spray drift. The APVMA’s proposed regulatory decisions were reported in a Special Gazette dated 30 July 2024 including that future use of these actives in vineyards is not supported. Environmental impacts have been reported as a key contributor to this decision – specifically the off-target impact on wild birds and wild mammals for paraquat, and impact on wild birds for diquat. Future use in many other crops is also at risk.
Some key determinations/proposed recommendations from the review include:
- Paraquat rated as having high toxicity to mammals and birds. Diquat rated as having high toxicity to birds and moderate toxicity to mammals.
- Paraquat use in vineyards (whether alone or in combination with another active) is not supported above a maximum of 45 grams of active ingredient per hectare, applied as a single application per year. This is well below the current maximum of 800 grams of active ingredient per hectare for vineyard application.
- Diquat use in vineyards (whether alone or in combination with another active) is not supported above a maximum of 88 grams of active ingredient per hectare, applied as a single application per year. This is well below the current maximum of 368 grams of active ingredient per hectare for vineyard application.
- For both paraquat and diquat actives – closed mixing and loading equipment required for all use situations; maximum handling rates per day by use and by active; no allowable application via backpack sprayer.
- Additional spray drift restrictions (around wind speed, inversion layers, nozzle size) and downwind buffer zones.
- Labels – additional headings related to the poison schedule for paraquat and combination paraquat labels only; addition of General restraints, Restraints for specific uses, First Aid and Safety directions, and Re-entry statement to all labels; additional export slaughter interval statement (paraquat and combination paraquat labels only), update of grazing statement and risk management statements relating to toxicity to birds and native mammals and aquatic life.
- A decrease in Maximum Residue Level (MRL) for paraquat from 0.05 to 0.01 mg/kg applicable to grapes.
The paraquat and diquat reviews are now in the consultation phase until 29 October 2024,during which time feedback can be provided to the APVMA on the proposed recommendations.
The wine industry is considering the proposed changes and working to assess these with other crop groups.
Following the APVMA’s review of the consultation stage submissions, they will publish their final regulatory decisions. For diquat this is expected to be in the week commencing 28 January 2025, and for paraquat in the week commencing 28 February 2025; at which stage the implementation periods will also begin.
Submissions
The wine industry’s national bodies are collectively staying abreast of discussions surrounding the paraquat and diquat reviews and are considering options around making submissions to the APVMA.
Interested parties wanting to either request further information or make a submission, can do so directly to:
Chemical Review Australian Pesticides and Veterinary Medicines Authority
GPO Box 3262
Sydney NSW2001
Phone: +61 2 6770 2400
Email: chemicalreview@apvma.gov.au
Submissions will be published on the APVMA website, unless you ask for the submission to remain confidential.
For questions about the paraquat and diquat review, or any other technical viticulture or winemaking question, please contact the AWRI helpdesk on 08 8313 6600 or helpdesk@awri.com.au.
Acknowledgements
The AWRI’s eBulletin is supported by Wine Australia, with levies from Australia’s grapegrowers and winemakers and matching funds from the Australian Government. The AWRI is a member of the Wine Innovation Cluster in Adelaide, South Australia.