Thirty top crosses of maize (ten inbred lines x three testers) were tested under full irrigation and water
deficit circumstances. To evaluate the combining ability of several traits in maize, these crosses were set in an
RCBD design with three replications along with two checks (SC 2031 and SC 128) in both environments.
Desirable mean values for 50% silking were detected for the crosses L25xM8 under normal irrigation and
L21xM8 under water deficit. The most desirable mean values for grain yield plant-1 were obtained for the cross
L29xM8 followed by L23xM4 under normal irrigation and L26xM4 under water stresss. For all examined traits,
non-additive was more important than additive in all environments. The tester T1 (M4) was the best for days to
50% silking, chlorophyll content, and grain yield, while the line L2 exhibited the best GCA effects for 100
kernel weight and grain yield. The highest significant and negative SCA effects for days to 50% were detected
for the crosses L25xM8 under normal irrigation and combined data. For grain yield, the cross L28x M4 gave the
best SCA effects under E1 and L29x M8 under E2 and combined analysis. The most desirable heterosis for
grain yield relative to both checks was obtained for the cross L23xM4 in the combined analysis. Also, the cross
L26xM4 expressed desirable heterosis for most traits under both environments. The cross L29xM8 recorded the
best heterosis values for days to 50% silking, 100-kernel weight, and grain yield under normal irrigation.