Diversity of cassava (Manihot esculenta Crantz) cultivars and its management in the department of Bouenza in the Republic of Congo

Cassava (Manihot esculenta Crantz) is one of the most produced and consumed food crops in the Republic of Congo. To assess the diversity and understand the traditional management of its cultivars in the department of Bouenza, twenty-one villages randomly selected from nine ethnic zones were surveyed using participatory rural appraisal. Altogether, 86 land races cultivars were recorded and further grouped into 36 types based on their agronomic and culinary characteristics. The number of cultivars accessed varied from 6 to 21 per village (13 on average) and from 1 to 11 (4 on average) per household. Their distribution and extent analysis revealed some worrying rates of cultivar loss in the range of 7.41–66.67% (32.06% on average) per village. The reasons of cultivars abandonment, the folk nomenclature and the traditional cutting supply system and planting techniques were documented and their importance in terms of genetic resources conservation and utilisation are discussed. Twenty farmers’ cultivar preference criteria were identified and prioritised. Their relative importances were examined across ethnic groups. Among them, the most important were yield, taste, cossette quality and root size which account for 72.39% of the total responses. The study revealed that most of the farmers did not consider the importance of the sexual reproduction in the cultivar diversification and the impact of cassava mosaic disease on the productivity of the infested plants. Awareness efforts and extension of the study to other cassava production zones were recommended for food security needs in Congo. To clarify synonym, morphological classification and molecular analysis were also suggested.