Herbage yield and morphological components of Mulato grass (Brachiaría hybrid 36061) under different grazing management

摘要

Three grazing frequencies (14, 21 and 28 d) and two grazing intensities (9-11 and 13-15 cm cutting height) were assessed in Mulato grass (Brachiaría hybrid 36061) in a completely randomized block design with a 3*2 factorial arrangement and three replicates. The following attributes were taken into account, herbage yield, growth rate (GR), botanic composition and/leaf:stem ratio. No significant interaction (P>0.05) was found between frequency*intensity for herbage yield. Herbage yield distribution was 55, 28 and 17 % respectively for the rainy, north and dry seasons in 2007-2008, evaluation period. The highest annual herbage yield (12,310 kg DM ha~(-1)) was recorded with 28 d grazing interval at 13-15 cm of grazing intensity. Herbage yield increasedprogressively when grazing frequency lengthened from 14 to 28 d (P<0.05). A similar herbage yield pattern was observed in 2008-2009. The greater growth rate (GR) was obtained in the rainy season, 36, 44 and 47 kg DM ha~(-1) d~(-1) at 14, 21 and 28 d grazing frequency, respectively. The lowest GR was found in the dry season. Relative to morphological components, the greater leaf mass yield was found in the rainy season, followed by the north and dry seasons at 28 d grazing frequency and 13-15 cm grazingheight. As a conclusion, the greater herbage yield, growth rate, leaf mass and leafrstem ratio were found in the rainy season at 13-15 cm grazing height and 28 d grazing frequency.