PERFORMANCE OF MAIZE CULTIVARS REGARDING NITROGEN USE EFFICIENCY

Nitrogen (N) is the nutrient that most interferes with maize productivity. The development of cultivarsefficient in N use is an effective strategy to reduce production costs and minimize the dependence on agriculturalinputs. The aim of this work was to evaluate maize cultivars as to their efficiency in absorbing and using N undercontrasting levels of this nutrient. The experiment was conducted in the experimental area of the Federal Universityof Lavras (UFLA), in Lavras, MG, Brazil, in the agricultural year 2006/07. The experimental design was randomizedblocks, with 20 treatments and three replicates, in a 10 x 2 factorial arrangement consisting of 10 cultivars and twoN doses. The characteristics evaluated were grain yield, dry matter weight and N content in grains and shoot. Thenutritional efficiency indices of the cultivars were also evaluated. The maize cultivars presented different behaviorconcerning most of the adopted nutritional efficiency indices. Contrasting nitrogen levels allowed the occurrence ofdifferences among the studied characteristics, which were necessary for the selection of the most efficient cultivars.The hybrids GNZ 2004 and P 30F53 stood out for presenting the best performances for the efficiency parameters used.