Early blight

Symptom

Caused by the Alternaria sp., this disease typically begins on the lower leaves, where small dark brown to black circular lesions appear. These lesions often have characteristic concentric rings with yellow halos, forming a distinct target-like appearance. Under severe infection, affected leaves turn completely yellow, dry out, and eventually fall off. When the disease spreads to the petioles and stems, elongated dark brown lesions with concentric ring patterns can be observed. The infection can also extend to peduncles and fruits. Entry often occurs at the fruit calyx or stem end, where dark necrotic spots first appear. In severe cases, premature fruit drop may occur, resulting in significant yield loss.