Twenty six new inbred lines of yellow maize were top crossed with three testers i.e. homozygous inbred line Sk 8008 and heterozygous i.e. SC Sk 74 and Comp-Sk 21 during 2005 growing season at Sakha Agricultural Research Station. The resultant 78 top crosses and the two check SC 155 and SC 3084 were evaluated during 2006 growing season at the two locations, Sakha and Sids Agricultural Research Stations.
The mean squares of locations were found to be highly significant for all studied traits except for No. of kernels/row. Significance for mean squares due to lines, testers and line x tester interaction was detected for all studied traits except of L x T for plant height and number of kernels/ row. The interactions between L x Loc. and T x Loc., proven to be were significant for all studied traits except for number of kernels/ row for the two sources and No. of rows/ear for T x Loc. The interaction between L x T x Loc. was insignificant for all studied traits except of ear diameter.
Additive genetic variance was more important component than the non-additive genetic variance in the inheritance of silking date, plant height, ear height, ear length, ear diameter, number of rows/ear and weight of 100 kernels, while, the non-additive genetic variance played the major contribution in the inheritance of grain yield and number of kernels/row.
Positive and significant phenotypic and genotypic correlations among most pairs of studied traits were recorded , except for silking date with No. of rows/ear, ear height with No. of rows/ear, ear length with ear diameter and No. of rows/ear and No. of rows/ear with weight of 100 kernels.
The best three way crosses were Sk 5001/6 x SC Sk 74 (34.5 Ard./Fed.) and SC Sk 5001/50 x Sk 8008 (33.63 Ard./ Fed.) were higher for grain yield that of the commercial hybrids SC 155 (31.32 Ard./Fed.) and SC 3084 (32.29 Ard./Fed.), suggesting that these crosses are fruitful for using in future in maize breeding programs.
Significant and desirable GCA effects were exhibited in Sk 5001/6, Sk 5002/9, Sk 5005/12, Sk 5005/16, Sk 5001/50 and Sk 7070/62 for grain yield and other studied traits.