Evaluation of Genetic Variability and Morpho-Agronomic Characters of Sweet Potato (Ipomoea batatas (L.) Lam.) from Umudike Germplasm and Selected Landraces from Southwest, Nigeria

Abstract

This study was carried out to evaluate the genetic variability and agro-morphological variation of thirty sweet potato accessions and selected landraces sourced from the National Root Crops Research Institute (NRCRI), Umudike, and local farmers from the six states of South West, Nigeria. The sweet potatoes were planted in the experimental field of the Department of Botany, the University of Ibadan using a randomized complete block design with four replicates. Planting was done on ridges of 6m long with a distance between ridges of 1m. On each ridge, 9 cuttings of 30 cm were planted at a spacing of 60 cm. Morphological data (Quantitative and Qualitative characters) were measured 90 days (vine and leaf characters) and 120 days (root characters) after planting in line with standard protocol. The means squares from the analysis of variance for the growth and yield characters indicated highly significant variability (p<0.001) among the sweet potato for the various characters studied. The mean performance of the growth and yield characters clearly indicated the agronomic superiority of some of the sweet potatoes over others. Storage root fresh yield showed a strong positive correlation with storage root dry yield (r = 0.71), and a strong positive association with the number of storage roots per plant (r = 0.70). The studied accessions had great genetic variability for all the characters. There is a need for farmers and plant agronomists to harness the great variability identified in this study for the improvement of sweet potatoes in Nigeria to enhance food security.