b'Disease A cross country check-in onDocketwhat to expect for potato diseases this growing season.BY: MARK HALSALLLATE BLIGHT HAS and very likely always will be something Canadian potato producers need to be vigilant against. Changing weather patterns, effective late blight early warning systems and control products have reduced the risk in recent years. But as any grower knows, theres no shortage of otherTuberspotato diseases which can spell trouble during the growing season. Here areinfected withsome to watch out for this year. late blight. PHOTO: KHALILAL-MUGHRABILATE BLIGHTPhytophthora infestans, the late blight pathogen responsible for the ruinous Irish potato famine of the 1840s, has been the scourge of potato growers around the world ever since. In addition to the staggering crop losses its caused, late blight has also been the most expensive potato disease to man-age, with a global cost of at least $6 billion according to some estimates.Its hardly a surprise, then, that late blight persists as the number one dis-ease concern for most commercial potato producers in Canada. In the last few years, however, effective late blight warning systems and changing climate conditions have contributed to a dramatic drop in the disease incidence.Theres been one or two positive late blight findings in the last two or three years, but we havent had widespread outbreaks, explains Dennis Van Dyk, vegetable crop specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs.We have a very good monitoring program here with a spore trapping net-work thats acted as an early warning sign for our growers and allowed them to be proactive in spraying.Late blight is always front of mind, but at this point, whether its because of the weather or because of the spore trapping network, I think we have a fairly good handle on it.Vikram Bisht, a plant pathologist with Manitoba Agriculture and Resource Development, notes commercial potato fields in Manitoba have been late blight-free since 2018, thanks in large part to the success of the late blight spore trapping network which alerts Manitoba growers when P. infestansPotatospores have been detected in the province. plants infected There were no reports in 2020 of late blight, even though we did trapwith late blight. PHOTO: KHALILsome late blight spores, says Bisht. We were able to warn growers and theyAL-MUGHRABIupped the ante on spray scheduling, which was extremely helpful.12 SPUDSMART.COM SPRING 2021'