World Journal of Agricultural Sciences

World Journal of Agricultural Sciences Vol. 5 (1), pp. 066-074, January 2017, ISSN 2329-9312©2017 World Science Research Journals 

Full Length Research

Variability in the yield and character association in Nigerian sweet potato (Ipomoea batatas (L.) Lam) genotypes 

Emmanuel E. Bassey 

E-mail: emmanuelessien@rocketmail.com, emmanuelbassey@uniuyo.edu.ng, Phone: +2348024686153 

Department of Crop Science, Faculty of Agriculture, University of Uyo, Uyo, Akwa Ibom State, Nigeria. 

Abstract 

The aim of the study was to determine the variability among 15 sweet potato genotypes and identify traits which are positively and significantly correlated with fresh tuber yield and also identify genotypes with high yield for the environment. A land area of 19m x 45m was laid out in a randomized complete block design with four replications. Vine length (cm), number of functional leaves per plant, leaf area per plant (cm2), number of branches per plant, tuber length (cm), circumference of tubers (cm), fresh tuber yield (t/ha), number of marketable tubers and non- marketable tubers per plot, weight of top growth, number of cracks and holes per tuber were studied. Significant differences (P≤ 0.05) were observed among the sweet potato genotypes for all the characters. UM/11/015 was superior over all the other sweet potato genotypes in three important characters, namely circumference of tubers, fresh tuber yield (t/ha) and number of marketable tubers per plot, followed by Solo 2 in two, namely tuber length and number of non-marketable tubers per plot.TIS 87/0087 was the next superior genotype for number of marketable tubers per plot and fresh tuber yield. The study showed that tuber length, circumference of tubers, number of marketable tubers and number of non-marketable tubers were significantly and positively correlated with fresh tuber yield (p < 0.01). However, number of branches per plant and vine length were negatively correlated with number of leaves, circumference of tubers, tuber length, and number of marketable and non-marketable tubers. Based on these findings, tuber length, circumference of tubers, number of marketable and non-marketable tubers are important traits that should be considered for selection in sweet potato. The high yielding genotypes showed weak resistance to holes and cracks in tubers. Therefore, UM/11/015, TIS 87//0087 and Solo 2 could be recommended for Uyo agro-ecology while UM/11/015 and Solo 2 could be advanced to the pre-released trials in the area. Four sweet potato genotypes, EA/11/025, CIP 420068, UMUSPO/3 and Butter milk which were generally vegetative and unproductive types could be eliminated from the list of sweet potato of Uyo environment. 

Keywords: sweet potato, variability, yield components, character association