First report of Dactuliophora species causing leaf spot of cowpea in India.
Mahadevakumar, S.; Janardhana, G. R.
Mycology and Phytopathology Laboratory, Department of Studies in Botany, University of Mysore, Manasagangotri, Mysore - 570 006, Karnataka, India.
New Disease Reports 2012 Vol. 25 pp. 17
British Society for Plant Pathology, Reading, UK
Language of Text
From 2010 to 2011, cowpea plants were found to be infected by a new leaf spot-causing pathogen in a survey conducted in the Mysore district, Karnataka, India. Leaf spot symptoms increased after rains, resulting in the death of infected plants. Initially, leaf spots appeared as small whitish lesions with concentric rings on the upper surface and were pinkish grey on the abaxial surface. As the disease advanced, the spots coalesced to form larger necrotic areas. These symptoms were persistent throughout the crop season, with sclerotia forming on the lower surface. On the lower leaf surface, sclerotiophores bearing sclerotia were produced from the immersed mycelium. Sclerotia were generally globose to irregular in shape and dark to grey brown in colour measuring 139.5 × 89 µm. Upon germination, germ tubes were produced over the entire surface of the sclerotium measuring 69.9 × 6 µm. The symptoms persisted throughout the crop season and affected the overall yield of cowpea. The fungus was identified as a Dactuliophora sp. based on cultural and morphological characteristics. This is thought to be the first report of leaf spot disease of cowpea caused by a Dactuliophora sp. from India.