Vangueria infausta (Burch) subsp. rotundata (Robyns) and Berchemia discolor (Klotzsch) Hemsl are drought tolerant multipurpose fruit trees indigenous to the lower Eastern Kenya. These fruit tree species are candidates for dryland agroforestry and could provide food, medicine and other commodities required by the local communities. Surveys conducted during this study showed that they suffer from dieback and canker. This main aim of this study was to assess the health status of Vangueria rotundata and Berchemia discolor and identify the pathogens that are causing the symptoms in the field. Samples were collected from two locations Tiva and Ikanga in Kitui county and one location Mkange in Makueni county. Isolations were carried out by growing the samples on malt extract agar supplemented with streptomycin sulphate. Morphological identification grouped the fungal isolates into 7 groups with the Botryosphaeriaceae family being dominant. DNA was extracted from the fungal. The fungal sequences isolated, were found to cluster within Botryosphaeriaceae, Sporocadaceae, Nectriaceae, Trichosphaeriaceae, Pleosporaceae, Diaporthaceae and Glomerellaceae
Using Koch postulates this study confirmed species of Botryosphaeriaceae: Lasiodiplodia sp.,Lasiodiplodia pseudotheobromae, Alanphillipsia aloeigena and Dothiorella longicollis as the possible causal agents of canker and dieback in the field through a pathogenicity test. Studies on the management of these pathogens are required to generate appropriate management strategies of the diseases.
Keywords: Vangueria rotundata, Berchemia discolor, canker and dieback, Botryosphaeriaceae