EVALUATION OF NEW YELLOW SINGLE AND THREE WAY CROSSES IN MAIZE

In order to estimate the general combining ability effects for both inbred lines and testers . Fourteen new yellow inbred lines of maize were top crossed to two testers, inbred lines Gz 656 and SC 162 at Sakha in 2012 season. The 28 top crosses (14 single crosses and 14 three way crosses) and two checks (SC162 and TWC 353) were evaluated at Sakha and Mallawei Agricultural Research Stations in 2013 seasons. Number of days to 50% silking, plant height, ear height, ear length, ear diameter and grain yield/plant were estimated. Significant differences between the locations were detected for all the studied traits except for number of days to 50% silking. Mean squares due to lines (L) and testers (T) and their interaction L x T were significant for all the studied traits except for T for ear height and L x T interaction for days to 50% silking, ear length and ear diameter. The additive gene effects were the most important component controlling the inheritance of days to 50% silking, ear length and grain yield/plant. Meanwhile, the non-additive gene effects played the major contribution in the inheritance of plant height, ear height and ear diameter. The best inbred line for general combining ability (GCA) effects  were  Sk 6004/40, Sk 5001/37, Sk6021/42, Sk6021/43 and Sk6021/43 for days to 50% silking, short plant and ear height, ear length, ear diameter and grain yield/plant, respectively. The tester inbred line Gz 656  had desirable GCA effects for short plant height, ear length, , ear diameter and grain yield/plant. While, the tester SC 162 showed desirable GCA for earliness. The best cross for specific combining ability (SCA) effects  was Sk6021/46 x Gz 656 for grain yield/plant. The best mean crosses for earliness, plant height and ear height were  Sk 6004/40 x SC 162, Sk 6004/40 x Gz 656  and Sk 5001/35 x Gz 656, respectively. Single cross Sk 6021/46 x Gz 656 did not significantly outyield the check SC 162 .similarly, were  the three way crosses Sk 5001/32 x SC 162, Sk 5001/33 x SC 162, Sk 5001/36 x SC 162, Sk 6006/41 x SC 162, Sk 6021/42 x SC 162  and Sk 6021/46 x SC 162 compared to check TWC 353. It could conduced that the new single crosses and three way crosses could be recommended for further testing in the hybrids development program .