Potato pest problem: CFIA finds pest in Manitoba field for the first time

A nematode is seen in this file photo uploaded June 19, 2026. (CFIA)

A pest that has the potential to greatly reduce potato production has been found for the first time in Manitoba.

The Canadian Food Inspection Agency (CFIA) said recent testing at a farm in southwestern Manitoba found the pest known as a golden nematode.

“Golden nematode is from a family of nematodes known as potato cyst nematodes, and they are able to multiply in potato fields and impact yields. When they are in heavy infestations, they can impact yields by reductions of up to 80 per cent,” said Patricia McAllister, the director of the Potato Division with CFIA.

She said these pests are microscopic worms, and more than 200 can be found in a cyst the size of a grain of sand.

The nematode is problematic as it attacks the roots of a potato plant, which prevents the plant from taking in nutrients.

“What makes this one tricky is some cysts will stay intact in the soil for up to 40 years, and they can survive without a host for that long, and that’s why this one is more difficult than some other pests to manage.”

She said the best way to fight back against the nematode is to plant resistant strains of potatoes that prevent the nematode from attacking the roots.

McAllister noted nematodes have been found in other provinces and U.S. states in the past, but noted this detection in Manitoba was “unexpected.”

The specific seed potato farm that was tested had not exported potato seeds to the U.S. over the last 10 years, but they started testing the soil as they were looking at the possibility of exporting.

McAllister said the farm had sold seed potatoes to other farms in the province. CFIA has identified the other fields that may have been exposed and additional testing is underway.

“With tools like our guidelines as well as resistant varieties, we believe the pests can be managed and we’re all working together to help contain, control and prevent its spread to other fields.”

CFIA said nematodes do not impact the health of humans or animals.