This devastating disease can infect peppers and tomatoes. Prevention is the key, as once the disease has taken hold treatment is not effective.
Bacterial leaf spot causes lesions that look like they are soaked with water. The spots usually appear on the lower leaves first, and as the disease progresses the spots are purple brown with a light brown center. When the spots appear on the peppers, they cause spotting and raised cracks, which open the fruit up to infection by other disease organisms.
There are no resistant varieties and there is no cure, although copper has been useful in prevention. There have been some reports of disease resistance to copper in some parts of the United States.
CROP ROTATION is the most effective means of prevention. Make a plan for crop rotation that spans 4-5 years, as this bacterium has been known to survive that long!
Rotation should include all members of the Solanaceae family-tomatoes, peppers, eggplant, and potatoes.
Remove all crop debris at the end of the season. This is where cleanliness comes in. Do not compost diseased plants. Once plants and debris are removed, till deeply to bury the bacteria.
Bacteria is spread by splashing water, so drip irrigation is always recommended. Stay out of the garden after a rain to avoid spreading the bacteria on your hands and clothes.
I KNOW that you are tired of me preaching CROP ROTATION whenever I talk about insects and disease in gardens, but believe me, IT WORKS!!!!!