Indigenous Knowledge, Farming Practices and Production Challenges for Cocoassié (Dioscorea praehensilis Benth.): Semicultivated Yam Intercropped with Cocoa

A semi-wild yam, Dioscorea praehensilis locally called ‘cocoassié’ in Côte d'Ivoire significantly alleviates poverty and enhances household nutrition in several West and Central African countries. Despite its economic and social importance and potential to improve food security, it remains scientifically overlooked and underutilized.

Using participatory rural appraisal (PRA) tools and techniques, 31 villages in eastern, midwestern and southwestern Côte d'Ivoire, selected according to the importance of D. praehensilis production, were surveyed. Information on using and managing D. praehensilis diversity and related folk taxonomy, agricultural practices and production constraints was collected and analyzed. The diversity of D. praehensilis was assessed using the Shannon Weiner diversity index (H’), Pielou's evenness index (E) and Margalef species richness index (d).

By synonymy, 18 landraces of D. praehensilis were identified. They were divided into four groups. Stem spine density, tuber root spine density and tuber flesh color are the main morphological characteristics used by farmers to describe the four groups of D. praehensilis. The Shannon diversity index (H’=1.30), equitability (0.72) and Margalef species richness (0.65) showed moderate diversity and distribution in the study areas. Farmers reported a decline in D. praehensilis production due to several factors, mainly limited rainfall (30.73%), high tuber flesh oxidation (18.7%) and short post-harvest self-life (15.46%). The most common storage method is pit storage (92.76%). In all study areas, D. praehensilis has a high food value and is important to food security.