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A genotype is considered to be most adaptive / stable, when it registers high mean yield but show a minimum interaction with the environment. Knowledge of genotype × environment interaction and yield stability are important parameters in breeding new cultivars with improved adaptation to environmental constraints prevailing in the target environments. Therefore, an effort was made to know the genotype - environment interaction and to identify stable single cross hybrids across the environments. Eight newly synthesized single cross maize hybrids and 7 checks were evaluated in a Randomized Block Design with three replications during Rabi-2016 across three locations spread over different agro-climatic zones of Karnataka state, India. Different stability parameters as suggested by Eberhart and Russell [1] were estimated. Joint analysis of variance revealed significant differences among environments, hybrids and environments × hybrids interactions advocating the adequacy of stability analysis. Hybrids, viz., MAI 349×MAI 283, KDMI 16×BGUDI 118 were stable for days to anthesis and silking, respectively. Whereas, hybrids viz., KDMI 16×BGUDI 118, BGUDI 120×VL 109252 and MAI 283× KDMI 16 registered mean values lower than the overall mean with bi value nearer to unity and non significant S2di for anthesis silking interval. Hybrid, MAI 349×MAI 283 for plant height and cob length, KDMI 16×MAI 283 for cob length, number of kernel rows-1 and 100 grain weight, BGUDI 88×MAI 349 for cob diameter, MAI 394×BGUDI 88  for shelling % and KDMI 16×BGUDI 118 for grain yield plant-1 registered stable performance across the environments. Based on the positive and negative environmental indices, production environment at location 1 (K Block UAS, GKVK, Bengaluru), was most favorable for expression of majority of characters studied. Hybrid KDMI 16×MAI 283 was found stable across the environments for most of the characters studied.

The present investigation was conducted to evaluate the various parameters of genetic variability and nature of associations among traits affecting grain yield in 50 inbred lines of maize (Zea mays L.) at Command Area Development Authority Experimental Block, Agricultural Research Station, Bheemarayanagudi (Karnataka) during Rabi 2018. The analysis of variance revealed that highly significant differences exist among the inbred lines for all the characters except for anthesis silking interval. High heritability coupled with high genetic advance (% of mean) was observed in number of grains per row, number of grains per cob, plant height, grain yield per plant, 1000 kernel weight and grain yield (kg/ha), indicating the influence of additive gene action in controlling the traits. The important yield attributing traits viz., shelling percentage, number of grains per row and plant height showed positive association at both phenotypic and genotypic levels. At phenotypic level, the character number of grains per cob recorded highest positive direct effect on grain yield followed by shelling percentage, days to 50% anthesis and plant height. At genotypic level, the characters viz., days to 50% anthesis, number of grains per cob, shelling percentage exhibited high direct positive effect on grain yield.