b'C anadianP otatoC ounCilA Flu Shot for Potatoes Potato researchers across the country are trying to develop a strategy to fight late blight. BY: ASHLEY ROBINSONWITH A HOT AND dry growing season across Canada during 2020, late blight wasnt a concern for most potato growers. But that didnt stop the research work from happening.Late blight is a disease that shows up largely when the conditions are conducive for the disease, and thats usually wet weather, and periods of a little bit cooler temperatures, Rick Peters, research scientist at Charlottetown Research and Development Centre, says in a phone interview. In any given year, we might see late blight more or less, in the different production regions and difference provinces, depending on the environment. Peters is the lead researcher on a five-year late blight research cluster project through the Canadian Potato Council with the Canadian Horticultural Council funded by the Canadian Agricultural Partnership (CAP). The project is currently in year two of five, but the research has been going on for much longer than that with Peters having studied it for years.With the current CAP project, Peters and his team of researchers from across the country are collecting late blight samples and focusing on two thingsidentifying the strains and what the characteristics of the strains are. This work is like what we do with the flu strains every year in Canada. We try to track which strains are going to be prevalent in any given year and then we sort of tailor the vaccine to try to matchup control of those strains, Peters says. Were trying to do the same thing with late blight, to see what strains of the pathogen are around the country and then give information on what sort of best management tools can been used to control those strains.Foliar late blight on a tomato plant leaf.PHOTOS: RICK PETERS, AAFC CHARLOTTETOWNIDENTIFYING THE STRAINSThe strains of the late blight pathogen present in Canada have changed and evolved over the years. Older strains have been replaced with newer strains.Were trying to get a handle on what strains of the pathogen are present because those change and, in some years, we see new strains come in that completely replace older strains and then we need to know what some of the characteristics of these new strains are, Peters says.In recent years, Peters team has observed the common A2 strain US8 has been replaced by a new A1 strain called US23. US8 was fairly resistant to Rid-omil and would aggressively attack potatoes. With US23 it is more aggressive on tomato plants and potato tubers than potato foliage.Weve really had to focus a lot on the tomato angle, not only for people that are growing tomatoes commercially but also home gardeners that like to grow tomatoes and have often been the source of disease for commercial potato growers that are nearby, Peters explains.In 2014, the US23 late blight strain popped up on Prince Edward Island on tomato transplants. The potato industry sprang to action informing tomato growers of the problems it could cause for potatoes with tuber rot.It never became a big problem in the potatoes in 2014 because it was identified early in tomatoes. Growers were extra vigilant to make sure it didntLate blight on a potato tuber. 36 SPUDSMART.COM WINTER 2021'