In response to Canadian allegations that faulty science and politics are behind U.S. restrictions on the transportation and importation of potatoes from Prince Edward Island, the United States will fire off a letter on Monday stressing that the requirements will stand, U.S. Rep. John Baldacci said Friday.

The dispute arose after a potato wart fungus was found in a field in New Annan on Prince Edward Island in late October. A fungal disease that makes potatoes unmarketable, the wart can be transferred in soil.

The U.S. initially imposed a ban on the PEI potatoes that was partly lifted in late December in lieu of strict requirements that included forcing all shipments through Houlton and subjecting them to inspection by U.S. agriculture officials. The ban still applies to potatoes from a nearly 100,000-acre quarantine zone.

The U.S. also demanded documentation of PEI potatoes transported within Canada to prevent potentially infected spuds from being repackaged elsewhere and exported to the United States.

In an effort to reopen shipments to the south, Canada agreed to try to meet the requirements in a letter sent to U.S. officials Thursday.

On Thursday, Terry Norman, director of Western Hemisphere trade policy at Agriculture Canada, said the restrictions are unnecessary.

“We’re doing this under protest,” Norman said. “We don’t think these requirements are scientifically justified but, in the interests of getting some exports from Prince Edward Island moving, we’re doing this.”

Canadian officials also filed a complaint on the restrictions under the North American Free Trade Agreement and said they weren’t sure they had the authority to enforce the restrictions on potatoes outside the quarantined area.

Baldacci said Friday that officials with the United States Department of Agriculture conferred earlier in the day and decided to send a letter to their Canadian counterparts Monday stating that they stand by the requirements and the science used to reach them.

The Congressman also said the USDA would call on Canadian officials to reconsider tracking and regulating the flow of potentially infected potatoes from Prince Edward Island to other provinces. Baldacci, who serves on the House Agriculture Committee, said there are concerns that this transporting of potatoes from one province to another without adequate regulation could spread the potato wart, and make it more difficult for U.S. officials to determine the origin of particular crop shipments.

He said the USDA was being overly cautious because it is so late in the year when it is difficult to identify the latent fungus which could cause permanent damage to potato crops if allowed to enter this country. The fungus also can affect tomatoes and other crops and can contaminate the soil for many years.

“The Canadians have to understand how serious this is,” Baldacci said. “The only other option the United States has is to close the entire border to all Canadian potatoes … which nobody wants.”