Evaluation of Maize Top Cross Hybrids for Grain Yield and Associated Traits in Three Agro-Ecological Zones in Ghana

Maize (Zea mays L.) is an important food crop in Ghana, but its productivity in farmers‟ fields throughout the country is generally low. The low grain yields can be attributed partly to the use of traditional low-yielding open-pollinated varieties. In an attempt to increase maize productivity, 39 top cross hybrids were developed using 21 inbred lines and 3 open-pollinated varieties. The trial was set up in a randomized complete block design with two replications in three locations in southern Ghana. The overall objective of the study was to investigate traits which influence yields in top cross hybrids and to ascertain the yield potential of the hybrids in three agro-ecological zones in Ghana. The Genotypes were evaluated to determine agronomic performances and correlations between yield and yield component traits were calculated to assess the degrees of associations. Highly significant variations (p<0.01) were observed among the maize genotypes for grain yield, cob length, cob diameter and kernel row cob-1 and significant variations (P<0.05) for days to 50% tasseling, days to 50% silking and kernel row-1. On the contrary, there were no significant differences among the genotypes for plant height and ear height. The significant (P<0.01) results for grain yield indicated the variable nature of the locations and differences in the performances of the genotypes evaluated. The mean grain yield was significantly (p<0.01) higher for the top cross hybrids than for the local checks.