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SARANAC LAKE - Late blight has made its way into North Country gardens.

More commonly known as the cause of the Irish potato famine in the mid-19th century, the disease has been found on tomatoes in Clinton County, Cornell Cooperative Extension expert Anne Lenox-Barlow said.

The fungus can be identified by lesions on the stem and olive-brown-colored spots on the leaves that look water soaked, as well as by a white fungal growth that appears in the morning when the leaves are still covered with moisture.

The fungal disease affects the solanaceae family of vegetables, which includes potatoes, tomatoes and eggplant.

According to Cornell University's Web site on pest management, late blight was a frequent problem for potato farmers in the U.S. until a fungicide was introduced in the 1970s. In the 1980s, a new strain of late blight found its way into the U.S. This strain was resistant to the fungicide and has since caused serious late blight epidemics in nearly ever major potato growing area of the country in the past several years.

Lenox-Barlow said there has never been such a large outbreak in this area.

"Every state in the Northeast is infected," she said. The infection ranges as far west as Ohio and east to the Atlantic Ocean.

Believed to be brought in from a large vegetable distributor based in Texas that delivered a crop of infected tomatoes, it first infected big-box stores such as Wal-Mart, Lenox-Barlow said. The spores can be carried on the wind, spreading the disease rapidly, she explained. Late blight is notorious for its ability to produce millions of spores quickly.

In this area, most tomatoes are grown in home gardens or at garden centers.

"The big concern is that it is airborne," said Kathy Steinbreuck, co-owner of Scott's Florist & Greenhouse in Saranac Lake and Lake Placid. "There are not a lot of tomato farms in this area, but there are some big potato farms." She pointed out that if a local farmer's or homeowner's tomato plants were to contract late blight, it could easily spread to the potato farms in the surrounding area.

Tucker Farms Inc., a family-owned and -operated potato farm in Gabriels, grows eight different kinds of potatoes as well as fruits, vegetables and grains.

"We spray fungicide once a week to prevent late blight," co-owner Steve Tucker said. The farm also has about 200 tomato plants, all of which look fine, Tucker said.

"I suggest finding a product with chlorothalonil," said Richard Gast, programs assistant for Cornell Cooperative Extension of Franklin County. Brand names would be Orthomax Garden Disease Control or Daconil2787. He also said that if you use chlorothalonil, it needs to be applied to the plants as a prevention, not as a treatment, for late blight.

"If you grow organically or for local restaurants, there are no organic pesticides that will work once the fungus has established itself on the plant," Lenox-Barlow said. Instead, she said, farmers growing organically should take precautionary measures before their crops are infected. Even if the plants are not being grown organically, the majority of pesticides used to treat late blight require a pesticide applicator license.

America's Master Gardener, Jerry Baker, recommends Blight Buster Tonic for the organic grower. This is a combination of one tablespoon light horticulture tonic, one tablespoon baking soda and one gallon of water applied to plants before they contract late blight.

Homeowners or farmers who believe their tomato plants may have late blight are asked to bring a sample of the plant to a Cornell Cooperative Extension office to be tested. The extension's nearest offices are Malone, Plattsburgh and Westport. The infected plant then needs to be completely taken out of the ground and bagged until it can be destroyed.