Response of the Yam Variety Krengle (Dioscorea rotundata) to Organo-mineral Fertilisation at Bouaké in Central of Côte d’Ivoire

The decline in yam productivity due to the lack of arable land and impoverished soils forces farmers to use fertiliser. The fertilisers used are mineral, organic or organo-mineral. A study of these fertilisers has been carried out to propose to the farmers a dose or combination that can improve their yield. Thirteen (13) fertilisers obtained from the combination of mineral fertiliser (NPK 15-15-15) and composted cow or poultry manure were tested on the yam variety Krengle in a 3 replicate randomized complete block design. The experiment was conducted over two (2) campaigns at Bouake in Central of Côte d’Ivoire. The results show that high dose mineral fertilisation (NPK 15-15-15, 300 kg/ha) negatively influenced the growth and yield parameters of the yam variety Krengle. High doses of organic fertilisers (Cow manure (CM) 20 t/ha and poultry manure (PM) 20 t/ha) have a positive effect on vegetative growth. While the medium-high doses of organic fertiliser (CM 15 t/ha and PM 15 t/ha) gave better tuber yield (13.5 t/ha) and allowed an increase in tuber yield from 17 to 18%. Organo-mineral fertilisation combining a small dose of organic fertiliser (5 t/ha) with a medium dose of mineral fertiliser (200 kg/ha) gave also fairly good yield (13.3 and 14.42 t/ha) with an increase of 15 to 25%. Thus, 200 kg/ha of NPK 15-15-15 associated with 5 t/ha of poultry or cow manure can be recommended for the cultivation of the yam variety Krengle at Bouake.