Circular, dark spots on leaves, resembling a "Bull's eye".
Symptoms
Spots merge, leaves turn yellow, and defoliate.
Disease starts on older leaves, spreads to stems, fruits.
Stem lesions cause wilting, death; fruits develop sunken spots.
The fungus overwinters on plant debris and soil, spreads through contaminated seeds, and thrives in wet, humid conditions, with nutrient-deficient tomato plants being more susceptible to early blight.
How is it caused?
Rotate crops with non-Solanaceae plants.
Avoid transplanting symptomatic seedlings.
Preventive Measures
Space tomatoes for air circulation, reduce humidity.