Single hybrid progenies of seven maize (Zeamays. L) genotypes were evaluated in Randomized Complete Block Design (RCBD) at the Centre for Agricultural Research and Extension, School of Agriculture and Agricultural Technology, Federal University of Technology, Owerri in the early and late cropping seasons of 2015. The objective of this study was to estimate the heritability, variance components, mean performance and correlation among the studied traits. Leaf area showed the highest mean heterotic value of 35.60% and 22.01 for MP and BP respectively. This was followed by days to 50% tasseling, percentage emergence, days to 50% emergence, stem girth and days to 50% silking in that order. Heterotic effect estimate for plant stand was negative, while that of plant height was positive in terms of Mid – parent heterosis (1.37%) and negative with Better – parent heterosis (-8.92%) for growth agronomic traits. . Number of grains per cob showed the highest mean heterotic value of 90.51% and 96.51% for MP and BP respectively. Heterotic effect estimate of plant stand was negative (MP = - 53.27%; Bp = - 51.17%) for yield attributes.
Results from the analysis of variance tests showed significant (P = 0.05) differences among the genotypes for most agronomic characters indicating the presence of variability. High genotypic coefficient of variation (GCV) was obtained for grain weight per cob (67.44 %) and the least for ear height (7.93 %) and high phenotypic coefficient of variation (PCV) was recorded for grain weight per cob (80.14%) while the least was recorded for ear height (11.32%). High heritability was obtained for days to 50 % taselling (89.54 %) while plant stand (28.82 %) had the lowest heritability estimate indicating that the presence of additive gene effects for potential crop improvement and so these characters could be improved through selection. This study revealed that there were high significant positive correlation between 1000 seed weight and plant stand (r = 0.55**), leaf area (r = 0.75**), plant height (r = 0.86**), stem girth (r = 0.71**), plant at harvest (r = 0.55**), number of row per cob (r = 0.57**), number of grain per cob (r = 0.58**) and field weight (r = 0.59**).
Keywords: Correlation studies, Heritability, Heterosis, South eastern Nigeria, Variance components