Potencial forrageiro de cultivares de cana-de-açúcar submetidas à adubação orgânica e química, em duas épocas de corte

Abstract

The sugarcane cultivation is of great importance to Brazil. It has, as main products, energy and sugar, being also used for other purposes, such as feed. The south of Minas Gerais state is an important milking basin in Brazil and it needs feeding alternatives for the animals during the dry season. To express its maximum potential as cultivation in the worked area, it is necessary to adjust its production factors and its producing area. The objective of the present work is to evaluate the cultivars of sugarcane submitted to different fertilizers and harvesting times. The experiment was installed in a twelve month cane under condition, in Fumal Farm, Baependi-MG, in a Typic Red Hapludox and in 266 DAP (days after planting) a severe frost happened. The experimental outlining was of randomized blocks in a scheme of sub-subdivided portions with three repetitions. The treatments were constituted by five cultivars (IAC86-2480, IAC93-3046, RB72454, SP79-1011 and SP80-1842), three types of fertilization (mineral, organic and organic plus mineral) and two harvesting times (August and October). The diameter, the length, the number per lineal meter of furrow and the percentages of rude protein, ethereal extract and fibers of the stems were evaluated. The yields of stems per hectare, dry matter per hectare and the percentage of stems were also evaluated. The results demonstrated the occurrence of significant effects among the cultivars, the fertilization processes and the harvesting times for the evaluated parameters. However the largest productivity of stems and dry matter per hectare was provided by the organic and organic associated to mineral fertilization processes, cultivars RB72454 and SP80-1842 and the harvesting times didn´t cause any effects in the yields of these parameters.