Estratégias para o rebaixamento do capim-marandu submetido ao diferimento: efeitos sobre a morfogênese.

Abstract

This work was conducted from January 2017 to June 2018, in Uberlândia, MG, Brazil, in order to understand how the different forms of lowering the canopy for deferment modify the morphogenesis of Brachiaria brizantha cv. Marandu (Marandu grass) during the deferral period. The experimental area consisted of a pasture with marandu grass, constituted of nine pickets. Three pasture depletion strategies at the beginning of the deferment period, which occurred in March / 2018, were evaluated: 1) grass maintenance with 15 cm for five months before deferral (15/15 cm); 2) maintenance of the grass with 25 cm from November / 2017, but at the beginning of the deferment period the pasture was lowered to 15 cm (25/15 cm); and 3) maintenance of the grass with 35 cm from November / 2017, but at the beginning of the deferment period grass was lowered to 15 cm (35/15 cm). During the deferment period, morphogenesis was evaluated in two cycles of 45 days, corresponding to the beginning and end of the deferment period. Leaf appearance rate (TApF) and stem elongation rate (TAlC) of basal and aerial tillers were higher at the beginning of deferral, as opposed to leaf life span (DVF), which was higher at the end of the deferral. Leaf elongation rate (TAlF) and TAlC were higher in pasture managed with 15/15 cm, in relation to the others. The maintenance of marandu grass at 15 cm for five months before the start of the deferment period results in higher tiller growth rates when compared to the intense canopy retention maintained high (25 and 35 cm) before the deferment period.