Study of Yield and Stability in Early Maturing Hybrids of Maize (Zea mays L.)

Nine new early maturing maize hybrids along with KSC301 as the check, were evaluated in six locations Karaj, Isfahan, Ardebil, Kermanshah, Sari and Khoramabad for two years 2001 and 2002. The experiments were conducted in a randomized complete block design with four replications. Each experimental unit was four rows spaced 75cm apart and 36cm within the row. Combined analysis of variance was carried out and stability statistics were also determined based on ten environments. Effects of environment, genotype and genotype environment interaction on grain yield was significant at 1% probability level. The stability parameters of ecovalance (W2i), stability variance (σ2i), regression coefficient (bi) and deviation from regression (S2di) were calculated. Comparison of mean yield using Duncan’s test showed that maximum grain yield belonged to hybrids (K1264/5-1 K 615/1) and (K 1263/17x S 61) with 10.25 and 9.98 tha-1, respectively. Hybrids (K 1728/8 K 615/1) and (K 2331
K 1263/2-1) both with grain yield of 9.73 tha-2 did not show significant difference with other hybrids. Overall stability analysis showed that hybrid (K 2331 K 1263/2-1) had acceptable mean yield and stability compared to the check hybrid and the other hybrids across the ten environments.