Post-harvest treatment of seed tubers with gibberellic acid and field performance of yam (Dioscorea cayenensis-rotundata) in Ivory Coast

Abstract

Tubers of white yam (Dioscorea cayenensis-rotundata) are often cut into segments for planting, so-called setts, whose weight and quality strongly influence yield. The effect of a post-harvest gibberellic acid treatment or manual desprouting of seed tubers on the quality of setts was investigated in a combined storage and field experiment over two years in central Ivory Coast. Although post-harvest losses were slightly reduced after four months of storage by both treatments, this had no effect on tuber yield. However, emergence and yield were significantly influenced by both the sprouting state at planting and the origin of a sett with respect to its position on the mother tuber. Limited resources should therefore be directed to apical setts and sprouted setts which have the highest yield potential. A GA3-derived distortion of the spatial distribution of sprouting loci leads to a more homogenous yield for setts of different origins. © 2005 Cambridge University Press.