On-farm diversity of sorghum [Sorghum bicolor (L.) Moench] and risks of varietal erosion in four regions of Burkina Faso

Local sorghum varieties managed and cultivated by farmers contribute in a large part in crop production of Burkina Faso. The loss of local sorghum varieties were reported, but very few investigations have been made on it. This study was conducted to assess the status of 739 local sorghum varieties collected in four regions of Burkina Faso and to identify the threats factors of sorghum diversity. A sample of 159 varieties identified as “rare” and described by the cycle length, the uses and disadvantageous characteristics has been submitted to a Multiple Correspondence Analysis (MCA) to determine sorghums groups and characterize them. The results showed a higher varietal richness in the North, East and Centre-East regions compared to the South-West region, with respectively 13.0; 11.7; 10.9 and 6.1 varieties per village. The MCA underlined four main groups of sorghum: custom sorghums, lain period sorghums and tincture sorghums, pharmacopeia sorghums and sweet-stem sorghums; they are characterized by lateness associated to the low grain productivity, earliness associated to the low grain quality, drought sensitivity. For these sorghums groups it appears that the climatic and socio-cultural changes are the main threats factors of sorghum diversity loss. Farmers' associations at regional level and research structures should in common develop suitable initiatives to follow-up and conserve sorghum diversity.