Targeting Late Blight in Canada

This year’s weather conditions in potato-growing regions of Canada are very conducive to an onslaught of late blight, which is caused by the oomycete Phytophthora infestans, and is considered one of the most devastating diseases of potato- and tomato-growing regions in North America.

“If the weather continues to be warm and humid during the day and cool at night, chances are the disease will spread—it won’t stop. Once you have it in a province it continues spreading, even if farmers use all the management tools that they have,” says Khalil Al-Mughrabi, a pathologist with the Department of Agriculture, Aquaculture and Fisheries in New Brunswick.

“With late blight, a field can look perfectly fine one day and overnight turns into a wilted mess.”

Al-Mughrabi helped form, and is also chair of, the National Potato Late Blight Working Group, an initiative aimed at gaining a greater understanding of the disease and reducing its impact on potato production in Canada. “The purpose of the working group is to determine what strains of late blight exist in the country, and with the cooperation of researchers across Canada we are coordinating this information to ensure all growers will have access to the same information,” says Al-Mughrabi.

Strain identification is currently being carried out by researchers in Alberta, Prince Edward Island, Ontario and Manitoba. Through the program, Canadian scientists are working together to help producers determine effective management strategies for late blight in their fields.