Phenotypic correlations among yield components in tropical maize lines under contrasting nitrogen conditions

Nitrogen (N) is an essential nutrient for maize crops, and identifying inbred lines tolerant to its deficiency is fundamental for genetic breeding. The objective of our study was to evaluate the phenotypic performance and estimate the correlations between yield components of 184 tropical maize lines under contrasting nitrogen conditions, over three growing seasons. Nine agronomic traits were evaluated and analyzed via mixed models and Spearman correlation. Significant genetic variability was found in both environments. N deficiency reduced the means of all traits, with grain yield (PG) standing out, showing a 51.68% reduction. Number of kernels per row (NGrF) and number of kernels per ear (NGrEsp) showed the highest positive correlations with PG under both HN and LN. The correlation between environments demonstrated high consistency for most variables, suggesting stability in selection. It is concluded that indirect selection through yield components is effective for obtaining superior inbred lines tolerant to N deficiency.