Estratégias para o rebaixamento do capim-marandu submetido ao diferimento: efeitos sobre as características estruturais do pasto

Abstract

This study was conducted from September 2018 to June 2019, in Uberlândia, MG, with the purpose of understanding how the different forms of forage canopy lowering for deferral modify the structural characteristics of Urochloa brizantha cv. Marandu (marandu palisadegrass) during the deferment period. Three strategies of grazing defoliation at the beginning of deferment period were evaluated: 1) maintenance of the grass with 15 cm for five months before the deferment period (15/15 cm); 2) maintenance of grass with 25 cm, but at the beginning of the deferment period the pasture was lowered to 15 cm (25/15 cm); and 3) maintenance of grass with 35 cm, but at the beginning of the deferment period the pasture was lowered to 15 cm (35/15 cm). During the deferment period, the structural characteristics were evaluated in two 45-day cycles, corresponding to the beginning and end of deferment period. At the beginning of deferment period both the number of basal and aerial tillers were higher in beginning than in final half of deferment period. The numbers of live leaves of the basal and air tillers were higher at beginning than at end of deferment period. The stem length and leaf blade length of the basal tillers showed higher values at end than at beginning of deferment period. The number of basal tillers was higher, both in initial and final deferment periods, in the pastures managed with 15/15 cm, compared to the others. Maintaining 15 cm pasture for five months before the deferment period increases the population density of the basal tillers, but reduces the number of aerial tillers, when compared to the intense lowering of the canopy maintained high (25 and 35 cm) before the deferment period