Identification of Characters Correlated with Tuber Yield in Guinea White Yam (Dioscorea rotundata Poir)

A study was conducted in 2016 cropping season in two locations (Itu and Uyo) in Akwa Ibom State, Nigeria to assess characters associated with fresh tuber yield in guinea white yam. The positive and highly significant correlations (p < 0.01) were established between fresh tuber yield and seven primary yield components in yam, namely number of ware yam per hectare (r = 0.814), fresh weight of ware yam per plant (r = 0.868), fresh weight of seed yam per hectare (r = 0.736), fresh weight of ware yam per hectare (r = 0.751), fresh weight of yam per plant (r = 0.986), circumference of tubers (r = 0.879) and length of tubers (r = 0.728), while positive and significant correlation (p < 0.05) was established between fresh tuber yield and vine length (r = 0.541). This study provides strong evidence that the yield parameters having important contributory factors to tuber yield should be considered in breeding and selection for higher tuber yield in guinea white yam. However, the negative correlation observed between fresh tuber yield and number of leaves per plant shows that number of leaves though an important morphological character is not a major contributory factor to yield in guinea white yam.