Both early blight and Septoria leaf spot are potentially serious diseases that affect the leaves, stems, and fruit of tomatoes. Early blight,
caused by the fungus Alternaria solani, can also infect eggplant. Septoria leaf spot is caused by Septoria lycopersici and can infect ground cherries, jimsonweed, and nightshade as well. Both diseases thrive during periods of moderate temperatures and abundant rainfall. They may occur on plants of any age, but they usually become evident after the plants begin to set fruit.
To find out how to spot, prevent, and treat early blight and Septoria leaf spot on your tomatoes, read this helpful fact sheet.
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