Fifteen yellow maize inbred lines derived from different hetrotic group were used in this study. In 2016
growing season the fifteen inbred lines were top-crossed to each of two testers In 2017 season, 30 top-crosses
along with four commercial check hybrids were evaluated in replicated yield trails conducted at Sakha and
Mallawy. Data were recorded for days to 50% silking, plant and ear height and grain yield.
Combined analysis over the two locations showed that mean squares due to crosses, lines, testers and line x
tester were significant for all the studied traits. Mean squares due to lines x testers were significant for all the
studied traits, indicating that differed in their order of performance in crosses with each of the testers. Mean
squares due to crosses x location, lines x location and tester x location interaction were significant for all the
studied traits, except no of days to 50% silking of line x tester. Mean squares due to lines x testers x locations
interaction were significant for all traits, except plant height. The magnitude of σ2 GCA was larger than that
obtained for σ2 SCA for all the studied traits. For grain yield, six single crosses i.e. L-1 x Mall.5035, L-2 x
Mall.5035, L-4 x Mall.5035, L-8 x Mall.5035, L-10 x Mall.5035 and L-11 x Mall.5035 significantly outyielded
the check hybrid SC-168. Only one cross L-3 x SC-162 significantly out-yielded the check hybrid
TWC-360.The best GCA effects were obtained from five inbred lines i.e. L-1, L-2, L-4, L-8 and L-11 for
grain yield exhibited positive and significant GCA effects. The top-crosses (L-1, L-8 and L-10 x Mall.5035
and L-3, L-5 and L-13 X SC-162) had positive and significant SCA effects.