CHARLOTTETOWN, Prince Edward Island – U.S. potatoes with the mop-top virus have been shipped by a Canadian agency to a Prince Edward Island lab for tests to check how infectious they are.

The potatoes containing the virus, a quarantinable pest that has been found in nine American states, arrived Wednesday.

The Canadian Food Inspection Agency in Ottawa already had reported that 115 potatoes tested positive for the virus over an 18-month period.

The discovery resulted in a ban on shipments of U.S. seed potatoes across the Canadian border.

The center for animal and plant health, where the analysis is being conducted, has extensive security systems in place to prevent the virus from accidentally escaping and infecting island crops, said Don Love, an agency official in PEI.

Solke Deboer, head of the center for expertise in potato diseases, said researchers will be busy testing the virus, which causes potatoes to rot and become disfigured, against various varieties of potatoes, to determine its virulence.

It has never been found in North America outside of a few backyard garden plots in the early 1990s in Canada, so its impact on North American spuds isn’t known, said Deboer.

In Maine, where the virus was first discovered in an experimental field run by the University of Maine, the Canadian agency’s testing procedures have fanned controversy.

Don Flannery, the Maine Potato Board’s executive director, said in earlier interviews that the agency hasn’t kept American producers abreast of its findings despite the discovery of the 100 positive tests in soil and potatoes headed for Canadian destinations over a year and a half.

Flannery said Canadian inspectors also should check fields in potato-producing jurisdictions north of the border, since it’s possible the virus may have reached the United States from seed and tablestock potatoes sent to American markets.