Pest risk analysis for ‘Candidatus Liberibacter solanacearum’ associated with apiaceous crops

​​​​The Department of Agriculture and Water Resources (the department) has completed a pest risk analysis for ‘Candidatus Liberibacter solanacearum’ associated with apiaceous crops.

There were three principal steps in the process:

  • The department’s experts conducted a review of scientific knowledge relevant to the pest to undertake the risk assessment and develop proposed risk management measures.
  • The department released a draft report for public comment on 11 December 2015 for a period of 45 calendar days via Biosecurity Advice 2015-23. The report outlines the identified risks and proposed risk management measures to address any risks identified and achieve Australia’s appropriate level of protection (ALOP). 
  • The department completed the risk analysis, taking into consideration all stakeholder submissions, and released the Final pest risk analysis report for ‘Candidatus Liberibacter solanacearum’ on 5 September 2017 via Biosecurity Advice 2017-20.

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Final Report Summary

The Department of Agriculture and Water Resources initiated this pest risk analysis (PRA) in response to the introduction of emergency measures against ‘Candidatus Liberibacter solanacearum’ (‘Ca. L. solanacearum’) infecting apiaceous crops, including carrot (Daucus carota) and celery/celeriac (Apium graveolens). This bacterium is not known to occur in Australia and is reported to cause serious damage to the carrot and celery industries in Europe. Australia introduced emergency measures on apiaceous host propagative material in August 2014 to manage the risk of introduction of ‘Ca. L. solanacearum’ into Australia.

The International Plant Protection Convention (IPPC) and the ‘World Trade Organisation Agreement on the Application of Sanitary and Phytosanitary Measures’ (SPS Agreement) requires that any phytosanitary measures applied against the introduction of new pests must be technically justified. The IPPC’s International Standards for Phytosanitary Measures (ISPM) No. 1 states that countries may take appropriate emergency action on a pest posing a potential threat to its territories; however, it requires that the action be evaluated as soon as possible to justify the continuance of the action. This PRA meets Australia’s international obligations to review the emergency phytosanitary measures on ‘Ca. L. solanacearum’ associated with apiaceous crops.

The department considers that the current emergency measures are adequate to mitigate the risk posed by ‘Ca. L. solanacearum’ associated with apiaceous crops. These emergency measures are recommended to become the standard conditions to import apiaceous host propagative material into Australia, with some minor amendments.

Since the publication of the Draft pest risk analysis for ‘Candidatus Liberibacter solanacearum’ associated with apiaceous crops, new findings suggested that this bacterium has expanded its natural host range within the Apiaceae family. It was detected in seed lots of carrot in Italy (2016) and Israel (2017), parsley seed in the UK (2016), parsnip seed (2016) and celery/celeriac seed (2017).

Most recently, ‘Candidatus Liberibacter solanacearum’ has been detected in plants of two other apiaceous crops: chervil and fennel in France (2017) and in imported fennel seed in New Zealand (2017). The detection of CaLsol in fennel seed has raised concerns that this bacterium may also be seed-borne in chervil. Based on the new available information, the department has made the following significant changes to the draft PRA:

  • The inclusion of mandatory off-shore or on-shore Polymerase Chain Reaction (PCR) testing or hot water treatment for celery/celeriac, chervil, fennel, parsley and parsnip seed; AND if the testing or treatment is conducted off-shore, a Phytosanitary Certificate with the additional declaration that the mandatory testing or treatment has been conducted in accordance with Australia’s requirements.
  • The inclusion of mandatory off-shore or on-shore PCR testing for chervil, fennel and parsley tissue cultures; AND if the testing or treatment is conducted off-shore, a Phytosanitary Certificate with the additional declaration that the mandatory treatment or testing has been conducted in accordance with Australia’s requirements.
  • The inclusion of mandatory growth of chervil, fennel and parsley tissue cultures not tested off-shore in a closed government post-entry quarantine (PEQ) facility for disease screening; AND mandatory on-shore PCR testing for freedom from ‘Ca. L. solanacearum’.

In addition, the department has also made several minor changes following consideration of stakeholder comments on the Draft pest risk analysis for ‘Candidatus Liberibacter solanacearum’ associated with apiaceous crops. However, these changes have no impact on the recommended risk management measures.

The recommended import conditions for apiaceous crops are summarised below.

Seeds for sowing (carrot, celery/celeriac, chervil, fennel, parsley and parsnip): mandatory off-shore or on-shore PCR testing or hot water treatment (50 °C for 20 minutes); AND if the testing or treatment is conducted off-shore, a Phytosanitary Certificate with the additional declaration that the mandatory treatment or testing has been conducted in accordance with Australia’s requirements.

Tissue cultures (carrot, celery/celeriac, chervil, fennel, parsley and parsnip) off-shore option: mandatory off-shore PCR testing; AND a Phytosanitary Certificate with the additional declaration that the testing has been conducted in accordance with Australia’s requirements.

Tissue cultures (carrot, celery/celeriac, chervil, fennel, parsley and parsnip) on-shore option: mandatory growth in a closed government post-entry quarantine (PEQ) facility for disease screening; AND mandatory on-shore PCR testing for freedom from ‘Ca. L. solanacearum’.

The department considers that the recommended risk management measures will be adequate to mitigate the risks posed by ‘Ca. L. solanacearum’ associated with apiaceous crops.

Next steps

The recommendations in the final report reflect the completion of the risk analysis for ‘Ca L. solanacearum’.

Import conditions will be published on the department’s Biosecurity Import Conditions System (BICON). Interested stakeholders can register in the BICON system and receive an alert when the case is updated.

Stakeholder Consultation

The department worked closely with industry stakeholders during the development of the emergency measures to minimise any trade and crop production disruption.

The draft pest risk analysis was released on 11 December 2015 for a 45 day stakeholder consultation period. All comments were considered in finalising this policy.

What is a pest risk analysis?

A pest risk analysis is the process of evaluating evidence to determine: whether an organism is a pest, if the pest should be regulated, and the strength of any phytosanitary measures to be taken against it to manage biosecurity risk.

If the risks posed by the pest exceed Australia’s appropriate level of protection (ALOP), the analysis will specify that the import will not proceed, unless appropriate measures have been identified that will reduce those risks to achieve the ALOP.

This pest risk analysis considers the risk of a pest associated with an import pathway, along with any sanitary and phytosanitary measures that could address this risk.

Considerations during a pest risk analysis

International obligations

All World Trade Organization (WTO) members are signatories to the Agreement on the Application of Sanitary and Phytosanitary Measures (the SPS Agreement), under which they have both rights and obligations.

The basic obligations of the SPS Agreement are that SPS measures must:

  • be based on a risk assessment appropriate to the circumstances or drawn from standards developed by the World Organization for Animal Health and the International Plant Protection Convention
  • only be applied to the extent necessary to protect human, animal or plant life or health
  • be based on science
  • not arbitrarily or unjustifiably discriminate between WTO members, or be a disguised restriction on trade.

Under the SPS Agreement, each WTO Member is entitled to maintain a level of protection it considers appropriate to protect human, animal or plant life or health within its territory – in other words, its appropriate level of protection.

Appropriate level of protection

The appropriate level of protection (ALOP) for Australia is defined in the Biosecurity Act 2015 as: a high level of sanitary and phytosanitary protection aimed at reducing biosecurity risks to very low, but not to zero.

This definition has been reached with the agreement of all state and territory governments and recognises that a zero risk stance is impractical because this would mean Australia would have no tourists, no international travel and no imports.

The ALOP is a broad objective, and risk management measures are established to achieve that objective.

Biosecurity risk​

The term ‘biosecurity risk’ is used to describe the combination of the likelihood and the consequences of a pest or disease of biosecurity concern entering, establishing and spreading in Australia.

Australia's biosecurity system protects our unique environment and agricultural sector and supports our reputation as a safe and reliable trading nation. This has significant economic, environmental and community benefits for all Australians.

Identifying risk

A risk analysis is an examination of the potential biosecurity risks associated with an import of animals, plants or other goods into Australia. It plays an important role in protecting Australia’s biosecurity.

If the assessed level of biosecurity risk exceeds the ALOP for Australia, the department will consider whether there are any risk management measures that would reduce the biosecurity risk to achieve the ALOP. If there are no risk management measures that reduce the risk to that level, trade will not be allowed.

Protecting Australia from exotic pests

A comprehensive risk assessment of pests and diseases has been undertaken and risk management options have been recommended to address any risks of exotic pests and diseases. Any recommended measures will reflect Australia’s overall approach to the management of biosecurity risk.

Zero risk is impossible; it would mean no tourists, no international travel and no imports of any commodities. Australia invests heavily in biosecurity to ensure risks are managed to the lowest possible level.

Australia exports almost two thirds of its agricultural produce. The future of our agriculture and food industries, including their capacity to contribute to growth and jobs, depends on Australia’s capacity to maintain a good plant and animal health status.

Australia accepts imports only when we are confident the risks of pests and diseases can be managed to achieve the appropriate level of protection for Australia.

New scientific information

Scientific information can be provided to the department at any time, including after a risk analysis has been completed. The department will consider the information provided and will review the analysis.

Contact information

For more information, stakeholders can email Plant or phone +61 2 6272 5094.​

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