Estimation of General and Specific Combining Ability of Maize Inbred Lines Using Single Cross Testers for Earliness

Maize (Zea mays L.) is third most consumed crop worldwide after rice and wheat. Maize is the main staple food in sub-Saharan Africa and Kenya, however, production has continuously been low over the past years. A line by tester analysis was carried out for 30 inbred lines and two testers to evaluate the GCA and SCA effects for yield and associated traits at three locations in Kenya during the 2016/2017 growing season. There were significant GCA and SCA mean squares indicating that both additive and non-additive gene effects contributed to the inheritance of the traits studied. Sum of squares of GCA was more than of SCA hence additive main effects contributed more to the inheritance of the traits than non-additive gene effects. Lines 1, 17, 6, 29 and 30 were good general combiners for grain yield. Testcrosses L30×T2 (4.40 t ha-1), L13×T1 (3.85 t ha-1), L20×T1 (3.59 t ha-1) and L9×T1 (3.52 t ha-1) yielded higher than best check mean and had good specific combining ability for grain yield and earliness in anthesis and silking dates. These genotypes can be evaluated further for grain yield and earliness and commercially released for use in areas with short rains.