Características agronômicas e produtividade de milho em função de épocas de semeadura

Abstract

Corn is the main cereal produced worldwide. In Brazil, it ranks among the largest cultivated crops. The grain is mainly destined for human and animal consumption. Its adaptability to the environment allows for an wide sowing period. This study aimed to evaluate the phenotypic and productivity components of 20 corn hybrids across four sowing periods to identify productivity components that can provide stability and yield across different sowing seasons (August, September, October, and November). Each sowing seasons corresponds to an experiment comprising 20 hybrids (A1; A2; A3; B1; B2; B3; B4; D1; D2; D3; F1; K1; M1; M2; P1; P2; P3; P4; P5; P6). The experiments were conducted in the municipality of Toledo-PR. The design used was a randomized block design (RBD), consisting of 3 replications. The evaluated variables were: male and female flowering in degree days, number of grain rows per ear, number of grains per row, ear diameter, ear length, ear insertion height, plant height, 1000-grain weight, final population, and yield in kg ha-1. Each experiment was subjected to analysis of variance, applying the F-test at 5%. Subsequently, the four experiments were analyzed together, and differences among the hybrids were identified and grouped using the SCOTT KNOTT test at 5% probability. Regression analysis was performed for comparison between sowing periods. It was concluded that the phenotypic characteristics of the hybrids and the productivity components are influenced by the sowing periods; the evaluated productivity components are significantly influenced by the sowing periods, except for the number of grain rows per ear; September exhibited the highest yield potential; the hybrids with the largest ear diameter across the periods achieved the highest average yields across the periods.