Evaluation of hybrid maize for grain yield and associated traits during the winter in Terai region of Nepal

Abstract

In Nepal, hybrid maize is increasingly popular in the Terai region due to rising demand for maize grains, higher yield potential, and superior agronomic performance. The purpose of this study was to assess the agronomic performance, yield stability, and adaptability of maize hybrids. A total of 23 single cross maize hybrids was evaluated at four locations in the Terai region of Nepal: Tarahara, Parwanipur, Rampur, and Khajura. The trial was laid-out in randomized complete block design with three replicates per location during the winter season of 2023-24. Flowering traits, growth, and yield-related traits were recorded following the protocols developed by CIMMYT. Analysis of variance was performed using ADEL-R, correlation analysis with PBTools, and stability analysis with GEA-R software. Results indicated significant genotype, environment, and genotype × environment interactions for all traits, with heritability estimates ranging from 0.78 to 0.96. The grain yield varied across locations, with Rampur recorded the highest average of 8.05 t ha^-1. RML108/RL2118, CML161/RML96, and RML36/RML2244 were the top performing hybrids with grain yield of 8.13, 7.93, and 7.85 t ha^-1 respectively. RML108/RL2118 identified as high yielding and stable (Pi=1.10) hybrid, RL143/RML96 as moderate in yield but excellent stability (bi=-0.10), while Sultan (bi=1.98) and RML62/RML2 (bi=1.69) showed poor stability despite high mean yield. The positive genetic correlations observed between days to anthesis with grain yield (r=0.31), ear position with grain yield (r=0.57), and kernel weight with grain yield (r=0.92). This study highlighted the value of multi-location testing to identify region-specific hybrids that are resilient to local environmental conditions. The results indicate that the identified hybrids possess high yield potential and can be promoted as candidate hybrids for winter season in the Terai region.