Diferentes materiais genéticos de Urochloa submetidos a adubação nitrogenada

Abstract

The aim of this research was to evaluate the responsiveness of different genetic materials of Urochloa as a function of nitrogen application. The experiment was carried out in a completely randomized design, in an 8x2 factorial scheme, with 8 cultivars of the genus Urochloa (“Mavuno”, “Convert HD 364”, “BRS Ipyporã”, “Cayana”, “780J”, “Sabiá”, “Marandú” and “Ruziziensis”) and 2 doses of nitrogen (0 kg/N/ha and 50 kg/N/ha), with 4 repetitions each. In total, 64 beds were used, with dimensions of 10m² (4m x 2.5m) each. The parameters of dry matter yield, canopy height, leaf:stem ratio, leaf elongation rate, stalk elongation rate, photosynthetically active radiation interception and leaf area index were evaluated. The results were submitted to statistical analysis using the SAS Studio program, with comparison of means using the Tukey test p < 0.05. The parameters evaluated in this study were not significantly affected by nitrogen fertilization, the differences being restricted only between the cultivars, however, there is a higher forage dry mass production (PMSF) in the fertilized Mavuno cultivar, with a value of 981 .90 kg/ha/cut, followed by the fertilized Sabiá cultivar, with 911.90 kg/ha/cut, so it can be assumed that the dosage used in this experiment (50 kg/N/ha) was not able to provide higher productivity, as well as significantly influencing the evaluated parameters.