Stability parameters for grain yield of maize hybrids (Zea mays L.)

Stability parameters for grain yield were evaluated in 11 maize hybrids of FAO 300-700 maturity groups (ZPSC 330M, ZPTC 404, ZPSC 42A, ZPSC 480, ZPSC 539, ZPSC 599, ZPSC 580, ZPSC 677, ZPSC 633, ZPSC 704, and ZPSC 753) at three different locations in Central Serbia over a two-year period. The hybrids were tested in two separate trials including 50,000 and 65,000 plants/ha, respectively. The stability parameters were estimated using the Eberthart and Russell regression model (1966). There were no significant differences (except in the ZPTC 404 hybrid) between the values of the regression coefficient (bi) for grain yield and the mean value. The ZPSC 599 hybrid of the group of hybrids with medium growing season gave high yields and less favourable values of stability parameters at most locations and over most years as compared to the long-season hybrids. The late maturity hybrids (FAO 600 and 700) as compared to the early maturity ones generally exhibited unfavourable values of stability parameters, i.e. a specific response and better adaptation to more favourable environmental conditions, and produced higher average yields. The yield of these hybrids could not have been jeopardized by the yield of the early maturity hybrids.