Effect of mineral fertilization on the organoleptic quality of "nyu" ignames from Passore in Burkina Faso

Abstract

Nyù (Discorea sp.) Is a special type of yam grown exclusively in the Passoré province. Today, its productivity
is hampered by the low fertility of the soil, leading to an increasing use of chemical fertilizers.
However, these mineral fertilizers would negatively impact the quality of the tubers. The present study
therefore aims to determine the optimal dose of NPK fertilizer which would allow an increase in the tubers
yield while maintaining the organoleptic qualities, in particular the taste. Thus, 41 nyù accessions collected
in the Passoré were evaluated at Mia under three NPK levels (T0 = 0 g, T1 = 50 g and T2 = 100 g) in
a Fisher block device with three replications for each dose of fertilizer using characters relating to the measurements
and the weight of the tuber and to the appreciation of the consistency and taste of the tuber by
a panel of actors. The results showed a gradual increase in yield with fertilization from 9,2 t / ha at T0 (0 g)
to 47,5 t / ha at T2 (100 g). However, this increase in yield is negatively correlated with the consistency
and taste of the tuber. Only the 50 g NPK dose showed an improvement in tubers yield (39,3t/ ha), with
maintenance of the organoleptic quality. Thus, for an improvement of the tubers yield and a maintenance
of the organoleptic quality, the dose of 50 g of NPK could be proposed for the production of nyù.