Correlations and path analysis of second-crop corn hybrids for maximum grain yield performance

The aim was to estimate the correlation coefficients and their direct and indirect effects through path analysis between agronomic traits that modulate the grain yield of second-crop corn hybrids. The hybrids SYN7G17 TL, 30F53VYHR, B2433PWU and AG 8700 PRO3 were employed. The following agronomic traits were evaluated: leaf nitrogen content, ear height, ear length, ear diameter, number of rows of grains per ear, number of grains per row, mass of a thousand grains, grain yield and grain protein content. Estimates of phenotypic correlation of all combinations of traits were calculated, and then the development of phenotypic correlations in direct and indirect effects was evaluated through path analysis, where grain yield was considered the main variable and the others were considered explanatory variables. Grain yield correlated strongly and positively with thousand-grain mass (0.83) and ear diameter (0.72). In the path analysis to tested conditions, no significant indirect effect was observed. However, the mass of a thousand grains and the ear diameter had a significant direct effect on the grain yield of corn, indicating that the selection of these characteristics can help to improve the grain yield in lines of corn