INFLUENCE OF INTERROW SPACING AND PLANT DENSITIES ON THE PERFORMANCE OF CORN CULTIVARS

Among the practices and techniques employed for obtaining greater corn yield, the choice of the ideal sowing density and the best arrangement of plants in the area are among the most important. This work was designed to verify the behavior of corn cultivars submitted to different interrow spacing and sowing density relative to grain yield. The experiments were conducted in the agricultural crops of 2000/2001 and 2001/2002 in an experimental area of the Department of Agriculture (DAG) of the Universidade Federal de Lavras. Each year, three experiments were established, adopting, respectively, the interrow spacing of 45, 70 and 90 cm. To each experiment conducted, three sowing densities were evaluated: 55 thousand, 70 thousand and 90 thousand plants ha-1 and 10 corn cultivars. Each experiment was conducted under the experimental randomized block design in a 10 x 3 factorial scheme with three replicates, ten being cultivars and three sowing densities. The data obtained were submitted to a single variance analysis per experiment initially. Afterwards, joint variance analyses were performed, one involving the three experiments from each year and the other taking into account all the experiments at once. The performance of the cultivars at the different densities and spacing is not coincident along the years, depending on the climatic conditions prevailing in the agricultural years concerned. With the exception of the cultivar UFLA-2, all the cultivars presented similar performance for grain yield regardless of spacing, density or agricultural year. The 70 cm spacing provided a greater yield in 2000/01 regardless of densities or corn cultivars utilized. But in 2001/02, there were no differences in spacing. The influence of densities at grain yield depends on agricultural years