UK Risk Register Details for Phytophthora infestans

Common Names

  • Downy mildew: potato
  • Late blight: potato
  • Late blight: tomato

Scenario and Pathways

Scenario for Risk Register

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  • National crop losses if effective 'fungicides' withdrawn

Pathway Assessed for Entry to UK

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Common Pathways

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This section is currently being developed as part of the next phase of the Risk Register.

Risk Ratings and Current Mitigations

Unmitigated Risks

Likelihood [1 - 5] 4
Spread [1 - 5]
Impact [1 - 5] 5
Value at Risk [1 - 5] 5
Likelihood x Impact [1 - 25] 20
UK Relative Risk Rating [1 - 125] 100

Current Mitigations

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Key mitigation for pest

Awareness of need for products by regulators



Industry Scheme

Contingency Plan



Mitigated Risks

Likelihood [1 - 5] 3
Spread [1 - 5]
Impact [1 - 5] 5
Value at Risk [1 - 5] 5
Likelihood x Impact [1 - 25] 15
UK Relative Risk Rating [1 - 125] 75

Proposed Actions

Proposed Actions



Management By Industry

Targeted Survey


Contingency Plan



Distribution and Pest Details


Country Status Notes
Europe Present (Widespread)
United Kingdom Present (Widespread)
North America Present (Widespread)
South America Present (Widespread)
Oceania Present (Widespread)
Africa Present (Widespread)
Asia Present (Widespread)

Type of Pest

  • Oomycete

Host or Industry at Risk

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Solanum tuberosum

Major Hosts

  • Solanum tuberosum L.

Threats to Protected Cultivation

Forest Tree Pests and Pathogens

Further Information

PRA Availability

PRA not available

EU and EPPO Listing

Not currently listed

Actions Indicated

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Monitor developments on EU regulation of pesticides and encourage the development of resistant varieties.

General Comments

A serious pest of potatoes currently managed by chemical control and crop production practices in the UK. This entry which considered the removal of the current effective fungicide treatments does not cover the likelihood of introduction of new resistant or more virulent races.

Risk Records for this Pest