Leaf spot of bean and blight of carrot. The diseases are characterized by dark brown to black spots often with concentric rings of sporulation. The older more senescent leaves and stems are attacked first often resulting in leaf drop from the bottom up. Target like spots can occur on the stem and may be sunken. These may result in the death of the whole stem and cause blight like syndrome.
Many species produce toxins both host specific and non-specific.
Favored by high humidity and warm temperatures. These diseases are all leaf spots very serious on banana and peas and other vegetables. Infection by conidia and ascospores causes the same disease. Generally leaf spots with some damage to fruit as shown for sigatoka disease of banana. Particularly with perennial plants and in areas with 12 month growing seasons.