Late blight case crops up in Lewis County

A case of late blight has been confirmed in Lewis County.

However, given that it is relatively late in the season, local agricultural officials say tomato and potato growers shouldn't be overly anxious about it.

"Home gardeners should just be diligent," said Michele E. Ledoux, executive director of Cornell Cooperative Extension of Lewis County.

A home gardener in Lowville with four tomato plants recently reported a potential late blight case to local extension officials, and the diagnostic laboratory at Cornell University, Ithaca, confirmed the disease Thursday, Mrs. Ledoux said. The plants have been removed and destroyed, she said.

Late blight usually starts on upper leaves and rapidly forms large dark dead zones on leaves and stems. A white fuzzy growth often shows on the underside of leaves at the edge of the dead zones.

As long as the tomatoes haven't been affected, they can be picked green and allowed to ripen inside after being wiped down with a solution of one part bleach and nine parts water, said Dolores B. DeSalvo, community nutrition educator at the Lowville Extension office.

"It's still safe to eat the tomatoes, but they're not recommended for canning," Mrs. DeSalvo said.

Green tomatoes should be ripened at room temperature, not in a sunny window, she said.

Plants containing late blight should be completely removed from the ground, sealed in plastic bags and thrown out, Mrs. Ledoux said. They should not be composted, she said.

Growers should check their crops several times a week for signs of the disease and report suspicious plants to their local extension office.

A relatively early-season outbreak of late blight — the disease responsible for the Irish potato famine in the mid-19th century — last year swept through the north country, destroying numerous tomato and potato plants.

However, growers shouldn't be "overly concerned" about it this year, since the disease hasn't cropped up until late in the growing season, Mrs. DeSalvo said.

Most of the earlier confirmed cases of late blight were in the western and southern portions of the state.

Cornell experts suspect the disease may have been carried here from the south by windborne spores, Mrs. Ledoux said.

Local extension officials already have sent information on late blight to commercial growers on their e-mail lists.