Identification of superior single cross hybrids for grain yield and its component traits of maize (Zea mays L.) for summer.

The study was conducted to assess the combining ability, nature of gene action and extent of heterosis in respect of grain yield and its component traits, involving 90 hybrids (developed through LxT design using thirty inbreds, three testers) and nine commercial checks in maize during summer and kharif, 2013 at MARS, University of Agricultural Sciences, Dharwad. Thirty inbred lines were crossed with each of three testers in a line × tester design to evaluate combining ability and heterosis to identify promising hybrids of maize for various characters viz., days to 50 per cent tasseling, days to 50 per cent silking, days to 75 per cent dry husk, ear length, ear girth, number of kernels row per ear, number of kernel per row, hundred seed weight, shelling percentage and grain yield per hectare. The resulting F1s along with three checks and the parents were evaluated during summer 2013. Analysis of variance revealed highly significant differences among the genotypes. Crosses excelled their perspective parents in performance for most of the traits studied. DMIL767, DMIL318 and DMIL326 among the parental lines and DMIL011 among the testers were identified as the best general combiner for grain yield. Whereas among the hybrids, DMIL765 x DMIL031, DMIL318 x DMIL011 and DMIL639 x DMIL011 were identified as a potential cross combination for grain yield while the cross DMIL765 x DMIL031 recorded highest magnitude of economic heterosis of 13.95 percentages over the best standard check. So the crosses DMIL765 x DMIL031, DMIL318 x DMIL011 and DMIL639 x DMIL011 can be utilized for developing high yielding hybrid varieties as well as for exploiting hybrid vigor.