African Journal of Root and Tuber Crops (2011) Vol 9. No. 1: page 1 A Research Article in AJRTC (2011) Vol. 9 No. 1: Pages 1-5 Survey of the current distribution and status of bacterial blight and fungal diseases of cassava in Guinea B.A. Bamkefa 1 , E.S. Bah 2 and A.G.O. Dixon 3 1 International Institute of Tropical Agriculture, PMB 5320, Ibadan, Nigeria. 2 Institut de Recherche Agronomique de Guinée, Guinea. 3 Sierra Leone Agricultural Research Institute, Freetown Corresponding Author: B.A. Bamkefa Email: b.bamkefa@gmail.com Manuscript received: 02/08/2010; accepted:15/11/2010 Abstract A survey was carried out of 86 cassava felds in the lowland savanna; humid forest, mid-altitude savanna, and lowland humid savanna agroecological zones of Guinea. Each feld was assessed for the incidence and severity of cassava bacterial blight (CBB), cassava anthracnose disease (CAD), Cercospora leaf blight (CLB), and brown leaf spot (BLS). Samples of diseased leaves were collected and used to identify associated pathogens. CBB was present in all the four major ecozones. The disease was observed in 88.88% of the felds visited in the humid forest. For other ecozones, results were 70.5% (mid-altitude savanna zone), 73.07% (lowland humid savanna), and 77.7% (low-land savanna). Anthracnose disease was observed in the humid forest and lowland humid savanna zones, but not in either of the others. CAD was observed in 11.11% of the felds visited in the humid forest, and in 19.23% in the lowland humid savanna. The disease was not observed in either of the others. CLB and BLS were observed in all the zones; however, the severity of both diseases was generally low and they did not seem to pose a serious threat to cassava tuberous root yield. Key words: cassava, bacterial blight, anthracnose, cercospora Introduction Cassava production is estimated by the Food and Agriculture Organization (FAO) at an annual global production of 202, 648, 218 t, Africa produces 108,109, 713 t. Out of these, Guinea produces 1, 350, 000 t (FAO Update to FAO, 2009). It is an essential part of the diet of more than half a billion people around the globe (FAO Update to FAO, 2009). The activities of various disease agents are some of the major constraints to achieving the full potential of cassava production in Africa. In cassava, losses in tuber yield from diseases can be as high as 90% (Wydra and Msikita, 1998). The need to protect cassava against diseases is, therefore, a crucial aspect in enhancing the production of the crop. Materials and Methods Farmers’ felds were surveyed across the four agroecological zones of Guinea between 8 and 30 of August 2005. The survey followed the method described by Ogbe et al (2003). The number of cassava farms examined in each ecozone varied, depending on availability. A total of 86 farmers’ felds were surveyed: lowland humid savanna (maritime Guinea) (26); humid forest (27); mid-altitude savanna (mid-Guinea) (17); lowland savanna (high Guinea) (18). In each farm, the assessment of disease severity was made on 30 randomly selected plants. Each plant was rated on a scale of 1–5 for cassava bacterial blight (CBB), cassava anthracnose disease (CAD), and Cercospora leaf blight (CLB); and on a scale of 1–4 for brown leaf spot (BLS) following the scoring system described by Wydra and Msikita (1998). Leaf samples with CBB, BLS, CLB and CAD symptoms were collected for the isolation of pathogens. Isolation and identifcation was made at the Crop Protection laboratory of Foulaya – Kindia. The geographic position of the each farm was recorded using the Global positioning system (GPS). Results Geographical distribution of cassava bacterial and fungal diseases CBB: CBB was present in all the four major ecozones. The disease was observed in 88.88% of the