Soil samples gathered from across Canada’s seed potato-growing areas have again turned up no sign of potato cyst nematode, the Canadian Food Inspection Agency reports.
The CFIA said Thursday it has analyzed over 44,000 soil samples collected from roughly 78 per cent of the country’s seed potato production area, for its nationwide PCN detection survey for 2011.
Among known PCN species, golden nematode most recently turned up in a single soil sample in each of two Alberta potato fields in late 2007, halting that province’s seed potato exports into the U.S. until early 2009.
Ottawa and Washington later agreed on new cross-border PCN guidelines, which include notifying the U.S. Department of Agriculture (USDA) prior to the deregulation of any field.
The U.S. market has since been open to all Canadian seed potatoes that meet PCN phytosanitary guidelines, not counting potatoes grown in "regulated areas" where the parasite species has turned up in the past.
Golden nematode and pale cyst nematode, the two PCN species found in Canada, are not a human health risk but are considered quarantine pests. If left unmanaged, the PCNs can reduce yields of potatoes and other host crops such as tomatoes and eggplants by up to 80 per cent.
PCNs are considered very difficult to eradicate as they can persist dormant in soil for several decades.
Both PCNs have also been confirmed in the U.S. and 63 other countries worldwide. Within Canada, both pale cyst nematode and golden nematode have been found in Newfoundland, while golden nematode has also been found in Alberta and Quebec and on Vancouver Island.
Another nematode species, potato rot nematode, most recently appeared in a garlic plot in the Ottawa area in mid-2011 and is "effectively controlled" on Prince Edward Island.