Nitrogen use efficiency in forage yield of tropical maize populations

Resumo

The development of adapted cultivars to nitrogen stress conditions is shown as an ecologically sustainable option to ensure higher yields in low input agricultural systems. This study aimed to evaluate the NUE in tropical maize (Zea mays L.) populations to forage production in the south of the State of Tocantins. Two experiments were done corresponding to low and high N availability sown on November 21, 2009. Twenty four maize populations and a commercial cultivar BR 106 were used in the experiments. The experimental design was a randomized block with two replicates. Plant height, ear height, ear participation in plant total green mass, ear green mass; plant green mass without ear, total green mass and NUE in forage production were evaluated. Through Moll methodology differences among populations for nitrogen use efficiency were found, however these differences weren’t found on Fischer methodology. Populations 12-4, 1-3, 12-6, 12-5, 26-1, 15-2, 25-2 and 1-5 are considered efficient in nitrogen use. The populations 12-6, 12-5, 12-4, 1-3, 1-4, 1-5 and 15-2 are the best populations to use in high and low N environment, combining great production of green mass and being efficient in N use.