Watch out gardeners! Late blight is back
Friday, August 13, 2010 - 5:29 pm

Late blight, the disease of tomato and potato that wiped out much of such crop plantings last year, has now been confirmed in several areas of New York State, according to Steve VanderMark of Cornell Cooperative Extension of St. Lawrence County.

VanderMark said today it has likely spread from other infestations further south.

Late blight now has been found in Genesee, Washington (north of Albany), Chenango, Broome, Livingston, and possibly Erie Counties, and in northern Vermont.

No late blight has been confirmed in St. Lawrence County or other nearby parts of the North Country, although common leaf spot diseases such as early blight are being found as usual.

VanderMark warns gardeners and growers to be extra alert for early signs of actual late blight, since it is now closer to us than it has been so far this year.

This crop-killing disease usually starts on upper leaves and rapidly forms large dark dead zones on leaves and stems. A white fuzzy growth usually shows on the undersides of leaves at the edge of the dead zones.

The other common leaf spot diseases have brown spots that grow together more slowly than late blight spots.

VanderMark advises gardeners and growers to check their crops now several times per week, in case a true late blight infection is weather-carried to our area from the infested areas in other parts of the state.

If found, actual late blight outbreaks should be reported to the Cornell Cooperative Extension office in Canton at 379-9192.

VanderMark suggests that, as a form of insurance, market growers and perhaps some gardeners may want to consider use of a preventative fungicide now on their crops before the disease gets any closer. Fungicides based on chlorothalonil or copper can be very helpful, he says.

Further details are available at Cornell Cooperative Extension of St. Lawrence County.