SASKATOON, Saskatchewan — Potato and tomato growers in Saskatchewan are on high alert after the fungal disease responsible for the Irish potato famine was reported in Saskatoon and Outlook last week.
"You can basically consider that the entire province is at risk right now,” said David Waterer, a professor at the University of Saskatchewan's vegetable program. “This is a disease that has the potential to move very, very quickly."
Late blight—a disease that predominantly attacks tomatoes, potatoes, peppers, eggplants and petunias—wreaked havoc on Saskatchewan's commercial and backyard tomato and potato crops in 2010, when it was last seen in the province. The disease thrives in wet, cool conditions and can spread quickly in windy weather.
Waterer identified the disease at a University of Saskatchewan research plot Monday. The following day, the plants were gone.
"It looks for all the world like a giant came down and just squished the plot with its thumb. It just went from absolutely beautiful four-foot-tall tomato plants to dead," he said.
According to Waterer, the disease is most deadly to tomatoes, which are directly exposed to the air-borne spores, but potatoes can also be ravaged if infected leaves aren't immediately removed.
"The commercial potato industry definitely fears this disease," Waterer said. "It has the potential to cause their plants to die out in the field, which will reduce yield, but even more devastating is the fact that the disease can go onto the potatoes. Then, during the subsequent storage period, the potatoes rot. So it's got the potential to get really nasty."
Jeff Curtis, a director with the Saskatchewan Seed Potato Growers Association, said the identification of late blight is "a big deal for a lot of people" and could cause a shortage of potatoes in the province if the disease spreads.
He said many concerned potato growers in Saskatchewan are now spraying their fields with expensive fungicides, which could reduce profit margins and quality of crops.
Late blight is identifiable by the presence of dark brown spots surrounded by light yellow halos on the edge of tomato or potato plant leaves.
Waterer recommends infected plants be removed as soon as possible and that the diseased leaves, stems and vines be buried or burned. Fruit from infected plants should be washed in a 10 percent bleach solution and rinsed with soap and water, but it may rot anyway.
"Once those spores get into the fruit, the fruit is doomed," Waterer said.
Gail Medernach, a vegetable farmer in Cudworth who sells her fares at the Saskatoon Farmers' Market, said she was shocked to hear late blight was identified in the province, and she will be checking her tomato plants more vigilantly in the coming weeks.
Medernach knows firsthand how devastating the disease can be; in 2010, it destroyed her crop, she said. "We didn't have any inclination that there was a problem until after we had harvested the fruit and then it just turned black," she said. "The entire tomato crop was gone."
The last time late blight appeared in the province, it was identified in September. Waterer said the disease's earlier appearance this year means it has "potential to be more damaging" than it was in 2010.
Source: Saskatoon StarPhoenix