<b>Production and chemical-bromatological composition of two cultivars of brachiaria fertilized with nitrogen and its relationship with the SPAD index</b> - DOI: 10.4025/actascianimsci.v31i2.4305

Abstract

The work was carried out in a green house, at the campus of Southwest Bahia State University-UESB, with the purpose of evaluating the production of dry matter in the external part (EPDM) and root (RDM) of Brachiaria brizantha’s cv. Marandu and Brachiaria decumbens’ cv. Basilisk, as well as their bromatologic composition and chlorophyll content (SPAD value), under different nitrogen doses (N). The experiment was conducted in a 4 x 2 factorial arrangement, using four N doses (0, 75, 150 and 225 mg dm^-3 N) and two brachiaria species: Brachiaria brizantha’s cv. Marandu and Brachiaria decumbens’ cv. Basilisk, in five repetitions using a randomized blocks design. EPDM increased with the enlarging of the N doses, while the opposite happened with the RDM. There was no difference in the content of crude protein (CP) between the two brachiarias; there was a linear increment as the dose of N increased. neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents were reduced as the level of N in the soil increased. The chlorophyll content was also positively influenced by the N supply. The brachiaria generally presented better development when supplied with N. Nitrogen fertilization improves the bromatologic-chemical composition of Brachiaria, because it increases CP and reduces NDF and ADF. The chlorophyll content, (SPAD index) can be used as indicator of the level of protein of the plant, and also as an indicator of the expected production of cv. Marandu and cv. Basilisk.