First Report of Black Leaf Mold of Tomato Caused by Pseudocercospora fuligena in North Carolina

Abstract

Diseased tomato (Solanum lycopersicum) samples were submitted to the Plant Disease and Insect Clinic from a commercial greenhouse in Sampson County, North Carolina in January 2017. Disease incidence was reported as moderately high with 25 to 35% of plants affected. Fungicide applications and routine leaf removal prevented spread to healthy plants. Pale yellow lesions were observed on the upper side of the leaves. Older lesions had brown centers surrounded by zones of pale-green to yellow. Blackish-gray fungal sporulation was observed on the underside of the leaf tissue in association with the lesions. Severely affected leaves appeared twisted, with dense, black sporulation visible. Microscopic examination revealed Cercospora-like conidia (Deighton 1976). Conidia were cylindrical, 35.77 μm to 91.42 μm long by 4.21 to 5.00 μm wide, with 3 to 7 septations per conidium (n=50). Conidiophores were 33.42 μm to 51.05 μm by 4.30 μm to 4.99 μm wide (n=25). Conidia were streaked onto clarified V8 juice agar (CV8A) a...