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UK Risk Register Details for 'Candidatus Phytoplasma asteris' in potato

This record was last updated on 29/05/2020

Common Names

  • Aster yellows
  • AY
  • yellow disease phytoplasmas

Scenario and Pathways

Scenario for Risk Register

  • show / hide
  • Pest is introduced

Pathway Assessed for Entry to UK

  • show / hide
  • Plants for planting (except seeds bulbs and tubers)

Common Pathways

  • show / hide
  • Plants for planting (except seeds bulbs and tubers)
  • Bulbs or tubers

Risk Ratings and Current Mitigations

Unmitigated Risks

Likelihood [1 - 5] 4
Spread [1 - 5] 3
Impact [1 - 5] 3
Value at Risk [1 - 5] 5
Likelihood x Impact [1 - 25] 12
UK Relative Risk Rating [1 - 125] 60

Current Mitigations

  • show / hide

Key mitigation for pest

Regulated non quarantine pest and prohibition of key pathway



Industry Scheme

Contingency Plan



Mitigated Risks

Likelihood [1 - 5] 2
Spread [1 - 5] 3
Impact [1 - 5] 3
Value at Risk [1 - 5] 5
Likelihood x Impact [1 - 25] 6
UK Relative Risk Rating [1 - 125] 30

Proposed Actions

Proposed Actions



Management By Industry

Targeted Survey


Contingency Plan



Distribution and Pest Details


Country / Territory Status Notes
United Kingdom Present (Limited) Not known to be present in potato, only other hosts
North America
Mexico Present
United States Present
China Present

Type of Pest

  • Phytoplasma

Host or Industry at Risk

  • show / hide

Solanum tuberosum

Major Hosts

  • Allium L.
  • Amaranthus L.
  • Anemone coronaria L.
  • Anethum graveolens L.
  • Apium graveolens L.
  • Callistephus chinensis (L.) Nees
  • Capsicum annuum L.
  • Catharanthus roseus (L.) G.Don
  • Chrysanthemum L.
  • Daucus carota L.
  • Delphinium L.
  • Fragaria L.
  • Gladiolus hybrids
  • Gramineae Adans., Nom. Cons.
  • Lactuca sativa L.
  • Morus alba L.
  • Oenothera L.
  • Paulownia Sieb. & Zucc.
  • Populus L.
  • Primula L.
  • Prunus avium ssp./var. avium L.
  • Prunus cerasus L.
  • Rosa L.
  • Senecio jacobaea L.
  • Solanum melongena L.
  • Solanum tuberosum L.
  • Tagetes L.
  • Tilia L.
  • Trifolium L.
  • Vaccinium L.
  • Veronica scutellata L.
  • Vicia faba L.
  • Zea mays L.
  • Asteraceae (family)
  • Hydrangea macrophylla

Threats to Protected Cultivation

Forest Tree Pests and Pathogens

Further Information

PRA Availability

PRA not available

Regulation and EPPO listing

  • show / hide

Regulated non quarantine pest

Actions Indicated

  • show / hide


Statutory action against findings. A survey to assess the distribution of Ca. Phytoplasma asteris in the UK and which sub-groups are present. Research into whether UK isolates infect potatoes.

General Comments

Phytoplasma pest with a wide host range, present in the UK, elsewhere in Europe and beyond. Not known to infect potato crops in Europe and import prohibitions effectively mitigate the risk of further introductions by this means.Uncertainty about the risk to potatoes are not infected and the role of vectors.