Stability parameters of commercial maize (Zea mays L.) hybrids

Many authors showed the possibility of developing highly yielding and stable hybrids. The assumption was that commercial maize hybrids were characterized not only by the level of average yield bat also by their stability. Fifteen commercial maize hybrids of medium late and late FAO maturity groups (400-700) were used in the present study. The two-year four-replicate trials were set up in six locations according to the randomized complete-block design. Stability parameters were determined after the method of EBERHART and RUSSEL (1966), in which the genotype was considered stable if it had a high average yield, a coefficient of regression of approximately 1.0 and deviation from regression as small as possible. The obtained results show that early maturity hybrids responded better to more modest growing condition and had a greater deviation from regression, while late maturity hybrids had a coefficient of regression closer to unity and they generally better responded to improved growing conditions.