OTTAWA -- U.S. officials will return to Canada this month to further assess this year's PEI potato crop, but documents show they have not always practised what they preach.

The Americans crippled the Prince Edward Island industry by shutting down the border to PEI potatoes after a fungus was discovered in a corner of a single field on Oct. 24.

Despite extraordinary measures by Canadian authorities and overwhelming evidence that the fungus had not spread, large sections of PEI farmland were quarantined and the border stayed closed for nearly seven months.

Yet when the same potato-wart fungus was discovered in Maryland in 1987, U.S. authorities did not bother to inform their Canadian counterparts, documents obtained under the Access to Information Act show.

Potato shipments to Canada continued uninterrupted and Canadian laboratories -- the same ones that the Americans second-guessed in the winter -- ultimately helped eradicate the fungus in Maryland, the documents say.

By contrast, Canadian authorities informed the Americans of the PEI problem within 48 hours. Inspectors from the Canadian Food Inspection Agency took nearly 300,000 soil samples from 74 fields.

They conducted 9,777 tests. Fifteen were positive -- all from the same 0.1 hectare where a man had a vegetable garden and fed his pigs.

More than 46,540 hectares of potatoes are grown on Prince Edward Island.

Still, PEI spuds were denied access to the lucrative U.S. Thanksgiving and Christmas markets while farmers in Idaho and Washington cashed in on bumper crops.

PEI farmers lost an estimated $30-million. Even shipments to other provinces were stopped in case the Americans made good on threats to ban their potatoes too.

In May, U.S. officials reopened the border to PEI's 2000 potato crop -- with conditions -- but they are still deciding whether to allow shipments of this year's crop.

"It is well and good for the U.S. to express their arrogance and demand that Canada segregate the most intensive potato geography of our entire industry," Paul Jelley, PEI's deputy minister of agriculture, wrote the president of the Canadian Food Inspection Agency on Dec. 14.

"We do not recognize this imposition since I assume we still have sovereign authority within our own country."

But what galled some Canadian authorities even more was what a New Brunswick official described as U.S. "disrespect" for the science conducted by the food- inspection agency.

"The same Canadian expertise that was turned to by the U.S. during the Maryland outbreak in the form of scientists, technologists and laboratories were once again used in this investigation," agency director Robert Carberry wrote his U.S. counterpart on Jan. 3.

In 84 years of export trade to more than 40 countries, he noted, there had never been a single finding of potato wart from Canada.

Yet thousands of trailerloads of Maryland potatoes have been imported since potato wart was discovered there. Wart has also occurred in Pennsylvania and West Virginia.

Shipments to Canada have also continued from other states where other, equally reviled diseases have occurred.

"It is a ridiculous situation where Canada has honourably allowed shipments of potatoes from areas of the United States where wart has occurred," PEI Agriculture Minister Mitch Murphy wrote federal minister Lyle Vanclief on Dec. 5.

"Further to this, it is also ridiculous that Canada allows potato shipments from areas of the U.S. where regulated and quarantine pests occur . . . yet we are refused reciprocity with our current situation. This is a clear violation of trade agreements."