Identification of new taxon of Colletotrichum as a causal pathogen for brown blotch disease of cowpea in the Sahelian zone of Burkina Faso

Brown blotch disease of cowpea was, until recently, described as a disease of savannah and forested zones of Africa. However, in its latest progression, the disease also appeared in the Sahelian zone of Burkina. In the present study on the etiology of brown blotch disease in Burkina Faso, analysis of isolates of Colletotrichum spp. lead to the identification of a new Colletotrichum taxon causing the disease in the Sahelian area of Burkina Faso. Based on its growth and microscopic characteristics, the new taxon differs from Colletotrichum capsici and Colletotrichum truncatum already reported as the 2 pathogens involved in the occurrence of the disease. Observed differences between studied isolates IMI 379432, IMI 379433, IMI 379434, and IMI 379435 of the new taxon, specific to Pobe area in Burkina Faso, and those of C. capsici and C. truncatum was confirmed by CABI-BIOSCIENCE (England). Additional work, using molecular techniques, is projected in near future for a better characterization of the new taxon of Colletotrichum reported in this study.