Crescimento de milho em níveis contrastantes de nitrogênio e sua correlação com produtividade de grãos

Abstract

The objective of this study was to evaluate the initial growth characteristics of genotypes of corn in pot experiment, with contrasting nitrogen levels, and afterwards to estimate the correlation among these characteristics with the grain yield and nitrogen efficiency obtained in the field experiments with the same nitrogen levels and genotypes. Two experiments were conducted in green house, one without nitrogen at seeding, and other with nitrogen equivalent to 150 kg N ha1. The experimental design was in randomized blocks with two replications, with the plot composed of two pots of 5 dm3 irrigated daily manually throughout the experimental period (until 49 days after seeding-DAS). The genotypes showed significant increase of approximately 34% in dry mass of aerial parts, and 25 and 24%, respectively, in stem diameter and plant height, with the application of nitrogen at seeding. Through the plant height at 10 days after seeding and the coefficient of linear regression of plant height under low nitrogen availability in pot, it is possible to identify partially, corn genotypes of good grain yield in the field conditions under the same nutritional status.