Cultivares, Doses de Fertilizantes e Densidade de Semeadura no Cultivo de Milho safrinha

Abstract

Out-of season corn is that one cultivated in the period of Fall and Winter, generally between the months of February to August, almost always after the harvest of the crop of early soybean. This Research was designed to evaluate the performance of five cultivars of corn submitted to three sowing densities, two doses of fertilizers in two years in Lavras, MG. Four experiments were conducted under the conventional growing system in an experimental area of the Department of Agriculture of the UFLA over the period of February to August of the years of 2004 and 2005. The experimental area were divided into two plots, where, in one of them, was evaluated the highest dose of fertilizers (400 kg ha-1 8-28-16 + 0.5 % Zn + 90 kg of N topdressing). In the other plots, was evaluated the lowest dose of fertilizer (200 kg ha-1 8-28-16 + 0.5 % Zn + 45 kg de N topdressing). In each experiment, the randomized block design in factorial scheme 5x3 was utilized, where the performance of five corn cultivars in three sowing densities (45, 55 and 65 thousand plants ha-1) was evaluated., a analysis of variance was performed for each experiment and afterwards, a joint analysis was undertaken involving the four experiments. The results obtained allow to conclude that: the density of 55,000 plants ha-1 provides yields similar to that of 65,000 plants ha-1, and superior to that of 45,000 plants ha-1; the adoption of the highest dose of fertilizers does not provide significant increases in corn grain yield; cultivars DKB 350 and AG 7000 had the best performance, the grain yield of the cultivars was influenced by the year of cultivation.