Genetic variability of yield and yield-related traits among 27 drought-tolerant maize genotypes

Maize is a valuable crop with high genetic variability, and understanding this variability is essential for improving crop productivity and resilience to environmental stressors. This study evaluated the genetic variability and heritability of yield and yield-related traits among 27 drought-tolerant maize genotypes in a humid climate region of Southwestern Nigeria. The experiments followed rigorous agronomic, soil, and climatic requirements for maize cultivation. Our findings revealed significant genetic variability among the traits of the maize genotypes, particularly in the number of ears per plant, which had the highest genetic advancement as a percentage of the mean (68.25 % and 67.83 %) under both well-watered and drought conditions, respectively. This suggests that breeding programs targeting this trait could significantly improve maize productivity and resilience to drought stress. Additionally, most of the agronomic traits targeted were highly heritable with heritability values ranging from 0.76 to 0.99 under both environments where the genotypes were evaluated, thus indicating that selective breeding for these traits could lead to consistent improvements in maize yields over time. Overall, this study highlights the importance of evaluating yield-related traits’ genetic variability and heritability in maize breeding programs. Findings suggest that targeting the number of ears per plant in drought-tolerant maize genotypes as revealed in the study could be an effective approach for improving crop productivity and resilience in regions with variable moisture regimes.