Effect of Nitrogen and Environment Interaction on Maize Yield Productivity

Variation in maize performance under different nitrogen fertilization regimes depends on genotype response, environmental conditions, and their interaction. This study evaluated three commercial maize hybrids contrasting maturity groups (G1–P9537, G2–P9911 and G3–P0412, representing early, medium, and late FAO maturity groups, respectively) across two growing seasons and five nitrogen treatments (0, 50, 100, 150, and 200 kg N ha−1) using the Additive main effects and multiplicative interaction (AMMI) model. Analysis of variance revealed significant genotype and environment effects on grain yield, whereas genotype by environment interaction (GEI) was not significant. However, decomposition of the GEI using the AMMI model indicated that the first interaction principal component (IPCA1) was statistically significant and accounted for 90.6% of the GEI sum of squares, indicating that the interaction component was predominantly described by a single multiplicative axis. Genotype G3 achieved the highest mean grain yield and low IPCA1 score, demonstrating relatively stable performance across the evaluated nitrogen environments in this study. In contrast, G2 exhibited narrower adaptation and was more closely associated with control and low-nitrogen environments, while G1 had the lowest mean yield but exhibited a low interaction IPCA score. These findings provide useful information for hybrid evaluation under various nitrogen environments and may contribute to improved nitrogen management and hybrid selection under conditions similar to those investigated in this study.