Late blight lesion on tomato leaf. Click for larger view.
Late blight is a “community disease.” It is very destructive. (It led to the Irish Potato Famine.) It is highly contagious among plants. And the pathogen produces many spores easily dispersed by wind.
That’s why Meg McGrath, vegetable pathologist at the Long Island Horticultural Research and Extension Center, created a series of brochures to teach gardeners how to prevent, identify and report the disease:
See also McGrath’s photo galleries: