Inventory of Major Post-Harvest Deterioration Agents oft National Yam Genetic Resources Collection at the CNRA Food Crops Research Station in Bouaké

Yam is a significant food source for populations in West Africa. During storage, diseases and infestations deteriorate the quality of the tubers, reducing their shelf life. To improve yam conservation during storage in Côte d'Ivoire, a study was conducted to identify the main pathogens and pests associated with yam tuber rot during storage. Sampling was carried out from the national yam genetic resources collection to collect tubers showing signs of rot. Two types of rot were observed, each with different coloration. Dry rot was black, brown, maroon, or green, while wet rot was brown, white, or black. On Dioscorea alata tubers, the cumulative frequency of dry rots (83.33%) was higher than that of soft rots. 60% of dry rots showed a black color. As for the tubers of the Dioscorea rotundata species, the cumulative frequency of soft rots was 48%, lower than that of dry rots with a frequency of 52%. The black color with a rate of 51% was higher than the other colors (maroon (34%); brown (14%); green (1%). Four fungal genera (Botryodiplodia sp., Aspergillus sp., Colletotrichum sp., and Fusarium sp.) and one pest insect (Euzopherodes vapidella) were identified in this study. Botryodiplodia sp. was the most isolated fungus with a frequency of 48 %. Pathogenicity tests were conducted on each isolated pathogen, with Aspergillus sp. proving the most virulent. The hybrid variety TDr10/00006 demonstrated the highest resistance to these microorganisms.