Early Blight
Alternaria solani
A common fungal disease that primarily affects tomatoes and potatoes. It causes characteristic "bullseye" lesions on leaves, stems, and fruit.
Symptoms
- Dark, concentric rings (bullseye pattern) on lower leaves.
- Lesions enlarge and leaves may turn yellow and drop.
- Dark, sunken lesions on stems and fruit.
- Reduced plant vigor and fruit yield.
Causes
- Warm, humid weather with frequent rainfall or overhead irrigation.
- Fungus overwinters in infected plant debris and soil.
- Stressed plants are more susceptible.
Prevention
- Practice crop rotation (avoid planting tomatoes/potatoes in the same spot for 2-3 years).
- Mulch around the base of plants to reduce soil splash.
- Keep foliage dry by using drip irrigation.
- Maintain plant health with proper fertilization.
Treatments
- Remove and dispose of infected lower leaves.
- Apply fungicides containing chlorothalonil or mancozeb at first sign of disease.
- Ensure good garden sanitation.