Evaluation of Genotype by Environment Interaction and Yield Stability of Early Maturing Maize Single Cross Hybrids at Three Locations in Southern Ghana

Multi-environment yield trial is essential in estimating genotype by environment interaction and identification of superior hybrids. Genotype by environment interaction effect on maize grain yield is usually significant due to large variation in soil and weather conditions at growing sites. The objective of the study was to evaluate 90 early maturing single cross maize hybrids and to identify stable and high-yielding hybrids with superior agronomic performance, to use GGE biplot to determine grain yield stability and the pattern of response of genotypes across three environments and to identify high yielding inbred lines that could be used as parental lines in hybrid development programmes in Ghana. The study materials comprised of 90 early maturing single cross hybrids tested across three environments, Fumesua, Ejura and Kpeve; representing the Forest, Forest-Savannahh Transition and Coastal- Savannahh Transition zones of Ghana, respectively. The experiment was laid out in a Randomized Complete Block Design with two replications at each of the sites. The Analysis of variance for grain yield demonstrated that genotypic and environmental mean squares effects were highly significant (P<0.01) while their interaction was only significant (P<0.05). The genotypes contributed 2.5 % of total variance while environment contributed 96 % of the total variance and their interaction contributed 0.95%. The genotype main effect plus genotype × environment interaction biplot explained 94.9% of total variation of G+ GE. The GGE biplot procedure provided results in terms of stability and performance of the hybrids and the discriminating environments. TZEI-36 X TZEI-39, TZEI-2 X TZEI-22, TZEI-11 X TZEI-15, TZEI-41 X TZEI-30, vi and TZEI-48 X TZEI-20 were identified as high yielding and stable genotypes while TZEI-45 X TZEI-47, TZEI-46 X TZEI-47, and TZEI-32 X TZEI-5, were very stable but low yielding. On the other hand, TZEI-22 X TZEI-45, TZEI-34 X TZEI-7, TZEI-10 X TZEI-11, TZEI-33 X TZEI-19, TZEI-48 X TZEI-20 TZEI-12 X TZEI-15, TZEI-45 X TZEI-34, TZEI-35 X TZEI-19, TZEI-25 X TZEI-23, TZEI-2 X TZEI-22, TZEI-22 X TZEI-48 and TZEI-34 X TZEI-46 were high yielding but not stable. The GGE biplot analysis identified Fumesua and Kpeve, located in the Forest and Coastal- Savannahh Transition zones as the most ideal environment for selecting high yielding genotypes. The correlation analysis revealed that grain yield was significantly and positively correlated with plant height (r = 0.633), cob length (r =.610) ear height (r = 0.410), and cob diameter (r = 0.443) and negatively correlated with anthesis-silking interval. However, grain yield did not correlate with days to silking. It was therefore recommended that the trial be repeated in several environments and years in order to effectively assess their yield potentials, the high and non stable yielding genotypes be tested extensively on farm and recommended for specific locations and that the high and stable yielding hybrids identified be further tested extensively on-farm and officially released for commercial production in Ghana.

Source: KNUST