Dinâmica do acúmulo de forragem e composição química do capim faixa-branca submetido a frequências de desfolhação

Abstract

This work was carried out with the objective of evaluating the dynamics of forage accumulation and structural characteristics of the Digitaria eriantha submitted to different defoliation frequencies from January 2015 to February 2016. Four frequencies of defoliation were evaluated: very (25 cm), high (35 cm), medium (45 cm) and low (55 cm), in two seasons of the year: higher sunshine (September to March) and lower sunshine (April to August). A randomized complete block design with four replicates was used. In general, the reduction in frequency of defoliation increased the interval between cuts, leaf area index, rates of total forage accumulation, stem and dead forage, and percentages of stalks and dead forage, accumulations of total deforest, Stems and dead fodder. In turn, this reduction in leaf defoliation frequency decreased leaf blade accumulation rate, leaf blade percentage and leaf blade accumulation and blade / stem ratio. The reduction in the frequency of defoliation increased dry matter, total carbohydrate and lignin content, as well as decreased crude protein content and estimated digestibility of Digitaria eriantha. In general, Digitaria eriantha presented higher rates of total forage accumulation, leaf blade and stalks, percentage of stalks and dead forage, shoot volume density and population density of tillers in the period of greatest sunshine. On the other hand, the Digitaria eriantha showed lower rate of accumulation of dead fodder and percentage of dead fodder in the period of lower insolation. Less frequent defoliation increases and increases the forage accumulation rates of Digitaria eriantha, but with less desirable morphological composition, contributing to a lower quality.