Potato wart is a soil-borne fungus, Synchytrium endobioticum, that can remain dormant in a field for more than 40 years.
Although potato wart poses no threat to human health or food safety, it does have a financial impact on potato growers by reducing their yield and making potatoes unmarketable. While potato wart naturally spreads slowly within a field, it often spreads rapidly within and to other fields by the movement of soil in association with farm equipment, cultivation practices, movement and planting of seed potato tubers from infected fields.
In Canada and many other countries, potato wart is a regulated pest. The Canadian Food Inspection Agency (CFIA) implemented control measures to help contain, control, and prevent the spread of potato wart both domestically and internationally.
Plant pests, such as potato wart, are regulated under the Plant Protection Act (PPA). When a regulated pest is detected a written notice is issued and outlines requirements under the Plant Protection Regulations. For example, it may trigger land-use restrictions, movement controls, requirements for equipment to be free from soil, soil sampling, and testing. The fungus is extremely persistent and the only efficient way to control the disease is to prevent the spread to new locations.
About potato wart in PEI
- Seed potatoes from infected fields are at the highest risk for spreading potato wart.
- When left unmanaged, potato wart can cause field losses between 50% and 100%.
- As of 2021, PEI has approximately 175 potato farms.
- Since 2000, potato wart has been found in 37 fields across all three counties of PEI.
- The CFIA began its most recent investigations after potato wart was detected in two separate fields on two separate farms in October 2021. This was the largest series of investigations since the fungus was first detected in PEI in 2000.
- The CFIA confirmed four detections: February 2022, July 2022, December 2022, and April 2023. Each detection was from a separate farm.
- The fields with detections in February 2022 and April 2023 last produced potatoes for processing in 2021, while the fields with detection from July 2022 and December 2022, last grew potatoes for processing in 2022. No off-island movement risk was identified during the trace-back and trace-forward activities of these detections.
- The field with the July 2022 detection had been planted with a potato wart resistant variety prior to the detection and the crop was harvested and processed with risk mitigation measures in place. The field with the December 2022 detection was harvested, stored, and processed with risk mitigation measures in place.
- In August 2023, the CFIA announced that it concluded its investigation into potato wart. By the end of the investigation, nearly 50,000 soil samples had been collected and analyzed concluding CFIA's recent investigations into potato wart.
- The Ministerial Order and the PEI seed potato domestic movement requirements remain in effect.
- The decision to implement the Ministerial Order was necessary to help further contain, control, and prevent the spread of potato wart in a manner that protects plant life and Canada's important agriculture sector.
- The Ministerial Order restricts the domestic movement of potatoes, soil, and other high-risk things (for example: root crops, nursery stock, sod, or bulbs) out of PEI.
- The end goal for managing infected fields is eradication. To accomplish this, stringent long term phytosanitary controls are applied.
Value of potatoes
- According to Statistics Canada, potatoes are the fifth largest primary agriculture crop in Canada (after wheat, canola, soybean, and corn). Potatoes contributed approximately $1.5 billion in income in 2021 and $2.6 billion in exports of potatoes and potato products in 2021/2022.
- In 2021/2022, Canada exported $37 million in seed potatoes, $421 million in fresh potatoes, and $1.9 billion worth of processed potato products to all countries.
- Potatoes make a significant contribution to the agricultural sector in some provinces; for example, in 2021, potatoes contributed over 44% of the total farm cash receipts in Prince Edward Island and 17% of the total farm cash receipts in New Brunswick.
- Manitoba and Alberta have higher total potato farm cash receipts than both Prince Edward Island and New Brunswick; however, potato farm cash receipts represent only 4% and 2%, respectively, of the total farm cash receipts for Manitoba and Alberta.
About PEI potato exports to the U.S.
- In 2021/2022, the U.S. export market represented 92% ($34 million) of seed potatoes, 97% ($403 million) of fresh potatoes, and 89% ($1.7 billion) of processed potato products.
- Currently, over 95% of PEI potatoes are eligible for movement to the rest of Canada as well as PEI's primary export market, the U.S.
- In November 2021, the United States Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) decided to no longer accept potatoes from PEI into the U.S.
- Countries are responsible for setting their own import requirements.
- The CFIA may only certify export shipments that meet the import requirements of the jurisdiction receiving the product.
- U.S. imports of PEI potatoes for consumption resumed under certain conditions in April 2022, when APHIS introduced new requirements to reduce the risk of bringing in potato wart.
- The current U.S. Federal Order prohibits the import of seed potatoes originating from PEI. Currently, the U.S. does not permit the import of field-grown seed potatoes from PEI and requires all imported fresh PEI potatoes to be washed free from soil, sprout inhibited, and graded to a U.S. No. 1 standard.
- The U.S. would need to change or repeal their federal order to resume importing seed potatoes from PEI.
Next steps for PEI potatoes
While the CFIA investigations into the two 2021 potato wart detections on PEI are now complete and the Ministerial Order remains in effect, there is still more work to do. CFIA continues to engage with stakeholders on the next steps including:
- Putting in place enhanced control measures, such as biosecurity and traceability activities.
- Additional surveillance of unrestricted fields in PEI that will help inform the development of long term activities designed to continue to mitigate risk and support the economic sustainability of the potato sector in PEI and across Canada.
Learn more about potato wart and the investigations in Prince Edward Island.