The Canadian Food Inspection Agency (CFIA) has detected golden nematode on a potato farm in Manitoba. It is a quarantine pest that does not affect human or animal health. However, if unmanaged, it can reduce production of potatoes and other hosts by up to 80%.
This is the first detection of the pest in Manitoba. It is present in some other Canadian provinces as well as numerous other countries, including the United States (U.S.).
There were no seed potato exports from the impacted field over the last 10 years. Phytosanitary measures have been applied according to the Canada and United States Guidelines on Surveillance and Phytosanitary Actions for the Potato Cyst Nematodes. Golden nematode and pale cyst nematode are collectively referred to as potato cyst nematodes (PCN).
Timeline
Following the 2025 potato harvest, soil sampling and analysis was conducted to support the export certification of seed potatoes. A detection meeting the definition of a 'suspect' case according to the Canada-U.S. PCN Guidelines was made.
Phytosanitary measures including restrictions on the movement of soil, potatoes and articles contaminated with soil, were applied to the suspect field at that time and additional soil sampling began on April 23, 2026, once weather permitted, to make the determination of the presence of golden nematode in the field. The suspect case was confirmed by a CFIA laboratory earlier this week using morphometric and molecular analysis.
The grower and key industry stakeholders were informed of the suspect detection and have been kept up to date throughout the investigation.
Ongoing work
Other fields that may have been exposed to soil and seed potato movement from the new index field have been identified through tracing activities and will be placed under official control. Soil sampling and analysis of exposed fields will continue through the summer and fall.
Information on this investigation will be posted to the CFIA's web site as it becomes available.
The CFIA delivers Canada's plant protection program to prevent and control harmful pests (insects, diseases, weeds) through strict import rules, domestic monitoring (surveillance), and international cooperation under the Plant Protection Act, protecting agriculture, forestry, and the environment from costly damage.
Quick facts
- PCNs can move with soil and are difficult to eradicate because they can persist, dormant in the soil, for up to 40 years.
- PCNs are different from potato wart as they are not a pest of potato tubers. PCNs attack the roots of the plant reducing yield.
- Washing potato tubers free from soil is a key risk mitigation for potato movement from regulated areas in both Canada and the United States as outlined in the PCN Guidelines.
- PCN has been confirmed in 65 countries worldwide, and in North America, PCN is currently known to be present in Newfoundland and Labrador; St. Amable, Quebec; Central Saanich, BC; and areas of New York State and Idaho in the U.S.
- PCNs are not harmful to human or animal health.
- Approximately 80% of the potatoes produced in Manitoba stay within the province for use as seed potatoes or for production into processed potato products.
