Alternaria Leaf Spot (Alternaria)

A fungal disease of tomatoes caused by species of the genus Alternaria, primarily Alternaria linariae (syn. A. tomatophila), and, according to some studies, also A. solani. It manifests as brown, circular spots with characteristic concentric rings on the leaves, stems, and fruits. The disease usually begins on the oldest leaves and then gradually spreads upward along the plant. Its development is favored by high humidity, frequent wetting of the leaves, and temperature fluctuations. Prevention primarily involves crop rotation, ensuring good air circulation around the plants, removing infected leaves, and avoiding wetting the leaves during watering. In cases of severe infection, the use of appropriate fungicides may be necessary.