Golden nematode detected for first time in Manitoba

The Canadian Food Inspection Agency (CFIA) has detected golden nematode on a potato farm in Manitoba. This is the first detection of the quarantine pest in the province.

Golden nematode does not affect human or animal health but can reduce production of potatoes and other hosts by up to 80% if unmanaged.

The pest is present in some other Canadian provinces as well as other countries. It was identified in New York in 1941.

There were no seed potato exports from the impacted field over the last 10 years, according to CFIA. 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).

Detection timeline

Following the 2025 potato harvest, soil sampling and analysis was conducted to support the export certification of seed potatoes. A detection was made meeting the definition of a ‘suspect’ case according to the Canada-U.S. PCN Guidelines.

Phytosanitary measures including restrictions on the movement of soil as well as potatoes and articles contaminated with soil were applied to the suspect field, and additional soil sampling began on April 23 to determine if golden nematode was present in the field. The suspect case was confirmed by a CFIA laboratory the week of June 15 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, according to CFIA.

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.

Additional information will be posted to the CFIA’s web site as it becomes available.

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. 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 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.