Phoma Leaf Spot
causes a leaf spot disease superficially similar to that caused by Alternaria solani, but the affected tissues are not depressed. Lesions are typically blackish rather than brown. Microscopically, light- coloured pycnidia (diameter 125-200 ?m) can be seen embedded in the affected tissue. Only the ostioles emerge through the epidermis. In later stages of infection, numerous small lesions may coalesce, so that leaves turn blackish and appear scorched.
- Reference: http://nt.ars-grin.gov/sbmlweb/onlineresources/NomenFactSheets/index_onLine.cfm?thisname=Phoma%20and
Presence among species