Optimisation of yam seed-tuber production by vine cuttings propagation
In Côte d’Ivoire, yam (Dioscorea alata L.) is the most important food crop, with 5.8 to 6 million tonnes of tubers produced over an area of 876,540 to 1 million ha from 2014 to 2018. Despite this performance, cropping practices have remained traditional. Part of the previous year’s harvest is diverted to be used as planting material for the current year. In response to this constraint, aerial stem cuttings appear to be an alternative method to obtain mini-seed tubers. This study aimed at optimising and standardising the technique for producing yam seed-tubers of the alata species, using cuttings from the aerial stems of two Ivorian varieties; namely Bètè-bètè and Florido. The study was carried out at the farm of the National Polytechnic Institute Félix Houphouet Boigny of Yamoussoukro (central region of Côte d’Ivoire). A Fractional Factorial Plan trial was therefore set up to assess 5 factors: the substrate, the sampling level and stage of the stem cuttings, coconut water and urea. The survival rate of stem cuttings and the weight of the minitubers obtained were measured. Results on the survival rate of var. Bètè-bètè reveal that this rate depends firstly on the sampling stage, then on the sampling level and finally on the interaction substrate x sampling stage. In var. Florido, the sampling stage had the greatest influence on survival rate, followed by the substrate and interaction substrate x sampling level. The interaction substrate x sampling stage has the greatest influence on the weight of the minitubers, followed by urea and then coconut water invar. Bètè-bètè. In var. Florido, the sampling stage is the most influential, followed by the interaction substrate x urea and finally coconut water and urea.
Key words: Côte d’Ivoire, cuttings propagation, Dioscorea alata