Genotype by environment interaction and grain yield stability of extra early maize (Zea mays L.) hybrids evaluated at three locations in Ghana

English

In Ghana, genotype by environment interaction effect on maize grain yield is usually significant due to considerable variation in soil and weather conditions at growing sites. A proper understanding of the effects of G x E interactions on variety evaluation and cultivar recommendations is vital. It was with this aim that this study was conducted to evaluate fortyfour extra-early maize hybrids obtained from the International Institute of Tropical Agriculture (IITA) and a local check hybrid to identify stable and high-yielding hybrids with superior agronomic performance for commercial production in Ghana during the 2011 growing season. These hybrids were evaluated at Ejura, Fumesua and Kpeve; representing the forest transition, forest and transition zones of Ghana. The effects of genotype (G), location (L) and G × L were found to be highly significant (P < 0·01) for grain yield. The variations among the genotypes (G) were the largest components of variance (79.16 %) for grain yield, whereas the locations effects and G × L accounted for 7.04 % and 7.37 %, respectively. The genotype main effect plus genotype × environment interaction biplot explained 0.97 of total variations in the sum of squares for grain yield. The GGE biplot procedure provided results in terms of stability and performance of the hybrids. This method identified the hybrids TZEEI 5 x TZEEI 4, TZEEI 1 x TZEEI 22, TZEEI 20 x TZEEI 19, TZEEI 31 x TZEE I8 and TZEEI 13 x TZEEI 22 as the high yielding and stable. TZEEI 11 x TZEEI 22, TZEEI 5 x TZEEI 50, TZEEI 8 x TZEEI 51 and TZEEI 8 x TZEEI24 are low yielding but stable. TZEEI 2 x TZEEI 11 and TZEEI 15 x TZEEI 8 was high yielding and the least stable and TZEEI 13 x TZEEI 12 and TZEEI 26 x TZEEI 24 had both low yielding and low stability. It identified Ejura, located in the forest transition zone, as the ideal testing environment for these set of hybrids.

Boakyewaa, G. A.