Didymosphaeria Leaf Spot of Cluster Yam (Dioscorea dumetorum). S. A. Emua, Department of Botany, University of Ibadan, Ibadan, Nigeria. A. O. Fajola, Department of Botany, University of Ibadan, Ibadan, Nigeria. Plant Dis. 65:443-444. Copyright 1981 American Phytopathological Society. DOI: 10.1094/PD-65-443.

A new leaf spot disease of cluster yam (Dioscorea dumetorum Pax) caused by Didymosphaeria donacina is described. The pathogenicity of both the perfect and imperfect stages of the causal organism was established. Symptoms developed 4 days after inoculation, and sporulation occurred 2 days later. Although the perfect stage of the fungus was found commonly on infected leaves, only sterile perithecia were observed in culture.