Press release from Cornell Cooperative Extension in Batavia:
Attention vegetable gardeners -- late blight has been confirmed in Genesee County!
This is a disease of tomatoes and potatoes so if you have either crop in your garden, you should be inspecting your plants and spraying with a preventative fungicide.
For home gardeners, chlorothalonil is usually the best preventative fungicide.
For those who grow organically, a copper product would be an option. The product label should list late blight and tomato/potatoes (whichever you are treating).
Remember – if you find late blight it is probably too late to save your plants.
Bag up diseased plants ASAP, preferably when the sun is shining and if possible, when the plants are dry. Let them cook in the sun in garbage bags, then dispose of them. DO NOT compost plants. The spores are airborne so leaving your plants alive will infect your neighbor's plants.
If you need help identifying it, please bring a sample to your local Cornell Cooperative Extension office – preferably in a clear, plastic bag.
Here's a PDF brochure to read about it here.
For more information visit this website.