Alerts

The plant pathogenic bacterium Xylella fastidiosa (Xylella) is Australia’s highest National Priority Plant Pest (NPPP).

The Department of Agriculture, Water and the Environment has identified the first scientific research that provides credible evidence for Xylella to be transmitted to pecan plants grown from infected pecan seed:

• Cervantes, K, Hilton, AE, Stamler, RA, Heerema, RJ, Bock, C, Wang, X, Jo, Y-K, Grauke, LJ & Randall, JJ 2022, ‘Evidence for seed transmission of Xylella fastidiosa in pecan (Carya illinoinensis)’, Frontiers in Plant Science, vol. 13, available at https://doi.org/10.3389/fpls.2022.780335.

Australia’s current emergency measures for Xylella host material are targeted at live plants imported as nursery stock. The department is now evaluating the new information to determine what emergency risk management measures may be required for host seed pathways such as Carya species and related genera. This is to ensure that Australia continues to manage the risk of this pest to meet an appropriate level of protection.

Next steps:
It is anticipated that proposed emergency measures for select nut species imported as seed for sowing will be implemented in May 2022, which may include the introduction of an import permit requirement to potentially affected host seed pathways that currently do not require one.

The department will continue to liaise with key stakeholders, including the Australian nut industry and states and territories, on the proposed measures. Trading partners will be notified of the emergency measures by the department through official channels.

The department is concurrently assessing potential risk management measures for imported seed for consumption pathways and will consult affected stakeholders at the earliest opportunity.

How you can stay updated:

• Further details on the proposed emergency measures, including the seed species affected and specific conditions, will be published through additional BICON Alerts and Industry Advice Notices before they are implemented.
• Keep updated by subscribing to the ‘Nuts and woody tree seed for sowing’ BICON case, using these instructions.

Background:
As Australia’s highest ranked NPPP, Xylella fastidiosa is known to cause significant disease in a range of host plants including grape, oak, almond, plum, forestry and amenity trees, olive, pecans, citrus, and other hardwood trees. For example, if introduced to Australia, it is estimated that Xylella has the potential to cost our grape and wine industry $7.9 billion over 50 years.

The bacterium has spread from the Americas to Europe, with recent detections in France and Italy, and would be very difficult to eradicate if introduced to Australia.

Many plant species show no symptoms when they are infected, and many are traded internationally as propagative material. Some insects in Australia are likely to be able to transmit the bacterium.

Australia currently has biosecurity requirements for many nursery stock plant species that could carry Xylella. Emergency measures for Xylella were introduced in 2015 to manage the risk of this bacterium due to an increasing global distribution and recorded host range. The department has continued to review and respond by evaluating the evolving risks and the new reports of novel pathways, new hosts and affected countries.

Further information:
Enquiries can be directed to 1800 900 090 or via email at imports@awe.gov.au (please title the subject line of the email with ‘Xylella emergency measures – Plant T2’).

Interested in finding out more about Xylella? Read about it here: https://www.awe.gov.au/biosecurity-trade/pests-diseases-weeds/plant/xylella