Fertilisation minérale des ferralsols pour la production d’igname en zone de savane guinéenne de l’Afrique de l’Ouest: cas des variétés d’igname traditionnelle sur

Abstract

Objective: To determine the optimal rate of NPK for improving yam production in the Guinea savanna ecological zone of Côte d'Ivoire. Methodology and results: A study was carried out on the mineral fertilization of four yam landraces, three belonging to the Dioscorea cayenensis-rotundata complex (Krengle, Kangba, Djate) and one to the Dioscorea alata (Bete-bete) species in 2000 and 2001 on ferralsols in the savannah zone of Côte d'Ivoire The trial design was randomized complete blocks with 4 replications per treatment. The soil was mostly sandy on the surface. Three treatments of mineral fertilizers were tested: T0 (check, without fertilizer), T1 (120 N, 38 P, 103 K), T2 (150 N, 49 P, 130 K). In general case, it a positive response of cultivars to fertilizer was noted. The highest yield was recorded with T1 (13. 2 t ha-1) against 11.6 and 8.3 t ha-1, respectively for T2 and T0, in each cultivar every ear. The T1 treatment seemed more efficient than T0 and T2. The variety Djate (22.3 t ha-1 ) in T1 was more productive in 2000 than in 2001. The comparison of the efficiency of the treatments for the same cultivar showed that T1 gave the best performance against T2 and T0. Conclusion and application of findings: Despite the response of cultivars to fertilization, yields still remain low compared to the potential of yam estimated at about 60-70 t ha-1. The treatment T1 could be recommended in intensive cropping systems. Based on this study we recommend further study combining mineral fertilizers and improved varieties with high-yield for sustainable production of yams on these soils which are very dominant in West Africa.