Late blight detected on crops in Western New York area

Aug 22, 2019

Firm, greasy-looking smears. Dark spots with fuzzy white spores. 


Farmers should be on the lookout for these warning signs after late blight — the plant disease best known for causing the Irish Potato Famine — was detected on crops in Cattaraugus, Allegany and Genesee counties over the last week. 



Late blight as seen on the leaf, stem and body of a tomato.
Credit Cornell Cooperative Extension

The fungus attacks tomatoes and potatoes, leaving dark spots and smears on the stems and leaves before eventually killing the crop after about two weeks. 


“We’re seeing complete losses on small acreage in some areas of Cattaraugus and Allegany counties so those farms are getting no crop off their tomatoes and potatoes,” said Elizabeth Buck, a vegetable specialist for the Cornell Cooperative Extension, which announced the detection Tuesday. “In that case, the growers then destroy the crop completely to prevent it from going other places.”


Buck asked farmers, as well as homeowners who grow tomatoes and potatoes, to contact Cornell Cooperative Extension if they suspect the disease. The farm-focused nonprofit based out of Cornell University is building a computer-based modeling to track the disease, and hopefully contain it.


Buck said late blight was spotted in Erie, Pa., and other parts of the northeast earlier this year, and was likely carried into Western New York by recent storm fronts. BlightUSA, a project tracking late blight throughout the U.S., currently reports cases in Pennsylvania, North Carolina and Florida, in addition to the local outbreak.


“If poorly contained, if we continue to have stormy weather, we could see this become something growers have to spend a lot of time and effort managing,” Buck said. “Of course, there’s economic loss associated with that too. Quite a bit of economic loss if say you lose an acre of tomatoes or a 20-acre field of potatoes.”


It’s estimated late blight causes $6.7 billion a year in yield losses worldwide, according to USABlight.


Guy Smith, president of Triple G Farms in Elba in Genesee County, said his onion and potato farm hasn’t been impacted by the current spread, but did have some late blight about 10 years ago.

“It was devastating to the crop,” he said. “We lost I think near 100 acres that year.”


Smith said his crops are usually scouted once a week, but will likely now be scouted at least twice a week until October’s harvest.