Produtividade de milho em função do tratamento de sementes, velocidade de semeadura, híbrido, espaçamento entre linhas e da densidade de plantas em semeadura tardia

Abstract

Corn is a crop of high economic and social importance in Brazil and around the world. This crop has widely versatile characteristics in its forms of consumption, and can be used mainly for human consumption, animal feed and as raw material for industry. A large part of the world's corn grain consumption comes from Brazil, which is the largest exporter of this commodity in the world. However, considering the low average productivity in the country, ways are being sought to increase them. Some factors, including the use of rhizobacteria that promote plant growth, adjustments in sowing speed, arrangement and plant density can contribute to obtaining greater productivity. Therefore, four experiments were conducted in a completely randomized design, with four replications, on second harvest corn in Santa Helena (PR), to evaluate the effect of these factors on corn productivity. In the first experiment, two seed treatments were evaluated (with or without RPCP Bacillus amyloliquefaciens PTA 4838). In the second experiment, treatments consisted of two sowing speeds (4 or 8 km h-1). In experiment 3, treatments consisted of three corn hybrids (P3282 VYH, P3310 VYHR and P3322 PWU). Experiment 4 was conducted in a 2 × 2 × 3 factorial arrangement. Two hybrids (P3310 VYHR and P3322 PWU) were evaluated, two spacings (single, with 0.50 m between lines, or twin lines 0.50 × 1 m, and three plant densities, 50 thousand, 60 thousand or 70 thousand plants per hectare). Seed treatment with B. amyloliquefaciens increased corn yield. Reducing the sowing speed from 8 to 4 km h-1 resulted in an increase in productivity. The P3322 VYHR hybrid showed higher productivity compared to the P3310 VYH and P3282 VYH hybrids. For both hybrids, the highest yields were observed in single spacing, at a density of 50 thousand plants per hectare. Therefore, the seed treatment with B. amyloliquefaciens, the sowing speed of 4 km h-1, as well as the choice of hybrid, the standard spacing of 0.50 m and the density of 50 thousand plants ha-1, are fundamental factors importance for increasing the productivity of corn hybrids in the Western region of Paraná.