Crop and climate researchers are engaged in an ongoing effort to discover which crop diseases Canadian farmers could face in the future and their possible point of origin.
“We’re seeing a general trend for pathogens usually found south of the border to make their way up to Canada,” says Albert Tenuta, a field crop plant pathologist with Ontario Ministry of Agriculture, Food and Rural Affairs. “This can be the result of adaption to environmental conditions. In many cases, we already have the diseases but they haven’t yet built up to the point where they’re a big risk on an annual basis.”
Wind-borne crop diseases represent a major threat because of the long distances they can travel, says Tom Fetch, research scientist with Agriculture and Agri-Food Canada Cereal Research Centre in Winnipeg, MB. “Rusts provide one of the best examples,” he says. “They overwinter in the southern U.S. and by the time our crops are starting to grow out in June, the rust spores arrive.”
The good news is that researchers have identified some of the potential pathways of common fungal diseases. The “puccinia pathway”, named after the rust genus, identifies the movement of rust spores from the southern U.S. to the eastern prairies of Canada. Stripe rust in the Pacific Northwest and Montana can travel up to Alberta and Saskatchewan, says Fetch. “Crops on the eastern prairies, however, are more vulnerable to stripe rust blowing in from Texas.”
Canadian researchers collaborate with key players in other locations — including corn and soybean grower organizations in the U.S. — in trying to anticipate diseases that could be a challenge on Canadian soil in the future, says Tenuta.
“One of the key diseases we’re tracking right now is frogeye leaf spot, a fungal foliar leaf disease commonly found in soybean crops in Kentucky and Illinois. It has developed some resistance to strobilurin fungicides in areas of the U.S.,” he says. Another is the bacterial disease Goss’s wilt in corn, which, over the past few years, has spread from Nebraska eastward into Indiana and Michigan.