This photograph of late blight on tomato plant was taken by Dr. Meg McGrath, Department of Plant Pathology and Plant-Microbe Biology, Cornell University.For more information about late blight, check out the following link from the New York State Cooperative Extension at Cornell University: http://vegetablemdonline.ppath.cornell.edu/factsheets/Potato_LateBlt.htm
For the home gardener, it came in on diseased plants shipped from the South and wiped out most tomato production in gardens in the Northeast. For most hobby gardeners, they would find it difficult to be able to assess this nasty disease. The most effective means of controlling late bight is to pull and destroy infected plants before the disease spreads, and it will quickly. There are also biological controls available, and we recommend that home gardeners go online and search for the topic for more preventative information.
There were a bunch of new gardeners last season that came into the marketplace, and unfortunately, their conclusion for the loss of tomato plants may have been the lack of a green thumb, and this was not the case. It is a sad event when families anticipate their very first, home grown tomatoes, only to realize that their plants have died in only a day or so.
Be vigilant!!! Go online and learn all you can about late blight.