- Wart and Mop Top Discoveries Change Potato Industry Outlook
- By Greg Brown
Associate Editor
- The discovery of potato mop top virus (PMTV) in a research plot in Presque Isle, Maine and the subsequent re-occurrence of potato wart on Prince Edward Island (PEI) could challenge traditional notions of plant pest quarantine.
At the very least, the virus woes of the North American potato industry could hasten efforts toward cooperation.
“A lot of people are talking about whether mop top is a retaliation for the previous potato wart quarantine,” said John Keeling, executive vice president and CEO of the National Potato Council. “What we do know is that the current situation is a humbling experience on both sides of the border - especially for everyone involved with trade.”
That current situation has the Canadians dealing with the return of the potato wart virus that cost the PEI industry millions of dollars, and both sides of the border investigating exactly what to do about PMTV.
Keeling called the discovery of PMTV a North American issue, saying it was essential that testing be conducted in both the United States and Canada so an effective management plan can be developed.
In late August, the Canadian Food Inspection Agency (CFIA) announced restrictions on the importation of U.S. seed potatoes due to an outbreak of PMTV. Less than 10 days later, on Sept. 4, the agency reported the discovery of potato wart on a farm on PEI.
USDA’s Animal Plant Health Investigation Service has confirmed the occurrence of PMTV in Maine and is evaluating the presence of the virus in the eight other states identified by Canada (California, Florida, Ida- ho, Maryland, North Carolina, Oregon, Virginia and Washington).
In the field PMTV can make potato plant leaves look feathery, but severely damages the potato causing vein-like rot on the inside of infected spuds. The virus poses no threat to humans but can ruin 50% of a potato crop and live in soil up to 18 years, according to researchers.
But how will both of the issues affect the industry and trade? “The latest thing we know is that it looks like we are going to be handling these issues one at a time,” said Keeling.
Keeling said APHIS continues to test protocols to evaluate the extent that the PMTV is found in Canada and the United States, he said. They are also investigating occurrence of potato wart on PEI, to determine any necessary changes to the disease management protocol.
From Canadian test results, APHIS is trying to trace back to the seed sources the origin of the PMTV virus, said Keeling. Tracing the alleged origins of the Canadian positives is very important to Pat Boss, executive director of the Washington State Potato Commission.
When the CFIA announced their management plan for PMTV, they reported that their lab analyses had recently confirmed the presence of PMTV in samples of chipping potatoes imported from 11 states. Boss questioned the inclusion of Washington on the list, and the dating of the import test – “In the case of our state, the two loads were dated July, 2001,” said Boss. “They didn’t bother to tell us of the results until last week, and they still have to tell us where the loads originated.”
The findings are bizarre, Boss said, in light of the fact that this farm has presumably been shipping potatoes since then and hasn’t had another positive since.
“It doesn’t make a lot of sense. We need more information we can use to go out and track down the origination.” So, the WSPC has requested more information from the Canadian government.
“If we do have mop top in Washington, Idaho and Oregon, we don’t have enough information to set up quarantines to prevent its spread,” said Boss.
Symptoms of the virus were first discovered in late May at the University of Maine Aroostook Research Farm in Presque Island, Maine, according to Terry Bourgoin, with the Maine Department of Agriculture. After the initial discovery of symptoms researchers took a period of time to verify that the symptoms indicated the PMTV was present.
Following verification Bourgoin contacted USDA and notified them that Maine had the virus and requested USDA confirm the test results.
Since then, the virus has been found in a commercial storage as the potatoes were being moved out of the storage.
How the situation will be handled, and how that protocol will affect next spring’s planting remains a big question. “There has been some discussion between the USDA and CFIA about developing some alternative approaches to PMTV other than quarantining individual operations.”
“If there were 117 positive tests from 11 states, mop top is probably pretty widely distributed,” said Bourgoin. “They have not, as far as I know been testing their own potatoes in the Northeast. But in the Atlantic provinces and states the soils are similar and there is a lot of movement of seed between New Brunswick and Maine.”
U.S. officials do know that CFIA has determined that PMTV was present in a number of gardens in the province of Quebec. Some industry officials have said that PMTV is probably present in other provinces - it is may be a matter of time before it is found in tests.
According to Bourgoin, the government agencies are discussing dealing with PMTV in a different way by developing some kind of management plan. “How that impacts Maine and Maine farmers is the key question,” he said. “We are on the front end of the discussion and are involved to some extent.”
But for now, the negotiations will wait while APHIS decides on a path through consultation with its Canadian counterpart.
Boss said that virus situation in both countries should lead to cooler heads prevailing in the creation of a management system.
According to Bourgoin, the process could move toward deregulating the PMTV virus. But, he says, if the industry has to wait for several months before something happens there could be a disruption of seed sales. “Operations all along the Eastern seaboard will need to have some kind of resolution soon.”
“The wart discovery has been unfortunate,” said Bourgoin. But, “they are two separate issues and they should be treated that way.”
Keeling said as the amount of cross border commerce increases and as the industry becomes able to test more effectively, the industry may find more incidences of such problems. “That is why we need to have effective plans to deal with these circumstances,” said Keeling.
“This is not going to be the last of these occurrences that we are going to have,” said Keeling. “That is why we need to continue to work cooperatively with them.”
