Improving the performance of a traditional variety of yam produced under ferralsol poor in organic matter in the forest areas of Cote d'Ivoire

Abstract A study on the potential of three previous cropping of ferralsol was conducted in the forest zone of Cote d'Ivoire from 1999 to 2000. These parcels were a fallow of Chromolaena odorata, a previous yam and a previous cassava. The aim of this study was to know the soil fertility and to assess the effect on the productivity of the local variety called “bete bete”, a water yam very widespread. Thus, two micro doses of NPK compared to a control without fertilizer was made for an objective of 30 t/ha. This work was carried out according to the pattern blocks of Fisher with six replications. It was obtained in 1999 under fallow the highest yield (22.4 t/ha) for T1 (24N 48P 36 K) against 18.4 t/ha and 14.4 t/ha respectively, yam and cassava subplot. In 2000, it was obtained under fallow 23.1 t/ha for T1 against 22 t/ha for T2 (70N 48P 36K). The lowest yield (12 t/ha) was obtained by T0 under cassava. The difference was significant between T0 and T1 and between T2 and T0 in 1999 and 2000 under previous fallow and previous yam. But, between T1 and T2, there was no significant difference. As cons, under previous cassava, there was no significant difference between treatments. The results showed that the fertilizer had an effect on bete bete yield. The conditions of cropping yam were more suitable under fallow than land previously cultivated but need manure to increase highly the yield.