A potato field near Kensington, Prince Edward Island, Canada, is under quarantine as the result of a suspected case of potato wart.

The suspect field is close to a field already known to be infected. 

David Cameron, acting regional director of the Canadian Food Inspection Agency, told CBC News Tuesday a single potato was pulled from the field with what appears to be potato wart.

The agency became aware of the incident Friday.

The potato is being analyzed in a lab in Charlottetown. 

In October 2000, the discovery of potato wart cost Island farmers millions of dollars when the United States shut its border to P.E.I. imports for six months.

But Cameron says he's confident that a protocol that was developed with the United States after the 2000 find will prevent another border closure.

The protocol, developed in conjunction with the U.S. Department of Agriculture, controls a crop suspected to be infected and the machinery used to harvest it.

Any fields that are confirmed positive are monitored and taken out of production.

The virus that causes potato wart is easily spread on plant material, machinery and soil. It can lie dormant in the soil for years.

Potato wart reduces the marketability of a crop by creating unsightly growths on tubers. The potatoes are still safe to eat.