Nitrogen-use efficiency of maize genotypes in contrasting environments

Abstract

The purpose of this study was to evaluate the nitrogen-use efficiency of 15 corn hybrids in different environments.The experiment was conducted at the research station Embrapa Milho e Sorgo, in environments with low (12 kg ha-1) and high(120 kg ha-1) nitrogen fertilization, in a randomized block design with three replications. The chlorophyll content, leafnitrogen and nitrate reductase activity in the flag leaf were determined at flowering and the grain yield was evaluated atharvest. The chlorophyll content proved to be sensitive to nitrogen availability, although without discriminating genotypicdifferences efficiently. To use nitrate reductase for this purpose, further studies are needed on the reliability of this biochemicalvariable to diagnose genotypes efficient in N use precociously. The hybrid L2xL3 was considered promising for maize breedingprograms aimed at gene introgression related to N-use efficiency.

Keywords

• Zea mays L.
• nitrogen
• chlorophyll content
• leaf nitrogen
• yield.