Establecimiento de gramíneas forrajeras tropicales en el bioma del Cerrado

Abstract

This study was carried out to evaluate the time for the establishment of tropical forage grasses in the “Cerrado” biome, based on morphogenetic and structural traits. Three Brachiaria brizantha (Syn. Urochloa brizantha) cultivars (Paiaguás, Ipyporã and Marandu) and two Panicum maximum (Syn. Megathyrsus maximus) cultivars (Quênia and Tamani) were distributed in a randomized-block design with four replicates. Morphogenetic and structural traits of the pasture were assessed from d 35 to d 65 after sowing, at seven-day interval. Canopy height rose linearly with the establishment period, in all cultivars. In the Megathyrsus cultivars, tiller density decreased as the experimental period progressed, whereas the number of tillers in the Urochloa cultivars increased. The cultivars Ipyporã and Marandu had the highest leaf appearance rates. The lowest leaf elongation rates occurred in the cultivars Paiaguás, Ipyporã and Tamani, and the highest elongation rates in cv. Quênia. As a result, cv. Quênia showed the highest values of final leaf length (64.9 cm) and leaf blade mass (3,352.9 kg DM ha-1). The higher senescence rate of cv. Tamani (2.1 cm tiller-1 d-1) resulted in the highest percentage of dead material (1,815.5 kg ha-1) being found in the herbage mass of this cultivar. Cultivars Paiaguás, Marandu and Tamani were established at 44 d, whereas cv. Quênia and Ipyporã were established at 51 and 58 d after sowing, respectively, in the Brazilian Cerrado.