Evaluation of slips of white yam (Dioscorea rotundata poir) genotypes for mini-tuber production in the humid tropics
The study evaluated the slips of four landraces and five hybrid varieties of white yam for growth and minituber yield in 2011 and 2012 cropping seasons at the National Root Crops Research Institute, Umudike, south east Nigeria. The experiment was laid out in a randomised complete block design with three replications. Landrace Hembamkwase had the longest vine (163.3cm), followed by hybrid TDr 89/02665 while Ame produced the shortest vine. Hembamkwase also out-yielded other genotypes except Ame in 2011 and Nwopoko in 2012. Generally, slips of the hybrid varieties, especially TDr 89/02665 and TDr 97/19177 performed poorly in tuber yield compared to the landraces. Mini-tuber weight showed significant and positive correlation with tuber yield while simple linear regression also showed high coefficient of association between tuber weight and yield. The higher yield associated with the landrace Hembamkwase was attributed to greater slip size, indicating that the landrace can be hybridized and the trait selected for in yam improvement.
Keywords: Dioscorea rotundata, yam slips, genotypes, mini-tubers