Plant Disease Destroying East End Crops

The same plant disease that caused the Irish potato famine is hitting East End farms again and it's worse than ever this year, according to a Cornell Cooperative Extension scientist.

Late blight, which is highly contagious among plants, most likely started in Sagaponack in late May or early June, according to Cornell. The disease causes dark lesions on tomatoes and potatoes — staple crops for many Long Island farmers — and then kills them, according to Margaret McGrath, a plant pathologist at the in Riverhead.

 “We have the worst outbreak in the U.S.,” McGrath said. “It’s a disease that doesn’t happen very often.”

Different strains of late blight have surfaced on Long Island since 2007, McGrath said. But, the strain attacking crops this year is a different one and has been tracked by Cornell to Wisconsin and western Canada, she said. It’s a sign that the disease may have started at a home garden before descending on the Sagaponack farm; a homeowner may have planted store-bought potatoes that originated in the affected regions, McGrath explained.

One South Fork farmer had to kill his entire first planting of tomatoes – a major financial blow – because of the destruction the disease caused, McGrath said. To combat further damage, the farmer has been regularly spraying fungicide on his other crops, McGrath said. Spraying fungicide is the only method to ward off late blight, other than killing the plants and using propane throwers to burn off diseased leaves, McGrath said.

Ed Harbes IV, whose family owns in Mattituck and Jamesport, said so far he has only spotted a “suspicious leaf” on a tomato plant. Harbes plucked the leaf from the stem and has been vigilantly watching for more signs on his two acres of tomatoes.

“It’s something we’re concerned about,” Harbes said, adding he's been using fungicide.

Fairview Farms in Bridgehampton also had one suspect leaf, said owner Harry Ludlow. Ludlow removed the leaf and has been spraying fungicide.

Ludlow said farmers have caught a break fighting the disease recently, as July’s hot, dry weather slowed late blight’s proliferation. June’s rainy, humid weather caused the disease to grow, he said.

“The spores need to stay moist,” he said.

Areas where water sits are also susceptible to the disease, said Joseph Gergela III, the executive director of the Long Island Farm Bureau. He said he has heard that late blight has hit tomatoes harder than potatoes this year.

Late blight could hurt farmers’ bottom lines at the end of the season, McGrath said. Farmers are spending more to protect their crops from the disease, and, to make up for the expense, might have to charge grocery stores and other distribution points higher prices for the produce, she explained. This could put areas not suffering from late blight at a competitive advantage.