The rice crop demands high nutrient input. In most areas where rice is cultivated, nitrogen is the main limiting factor to yield and nitrogen fertilization represents the largest fraction of the total production cost. This study aimed to assess the effect of low and high nitrogen rates on flooded rice cultivars sown in a lowland soil without a controlled flooding system. Nine flooded rice cultivars were used in the experiment: BRS-Jaçanã, Metica-1, Best-2000, BRSGO-Guará, BRS-Alvorada, BRA-01381, AN-Cambará, BRS7-Taim and EPAGRI-109. Nitrogen at the rates of 20 and 120 kg ha-1 were used to simulate environments of low and high N levels, respectively. The following characteristics were evaluated: plants height, grain yield and 100-grain mass. Genotype EPAGRI-109 was the best statistic group for both low and high nitrogen levels and the environment with high nitrogen level produced the highest plant heights.
Oryza sativa L.; cultivar evaluation; mineral stress
