Características produtivas e tecnológicas de variedades de cana-de-açúcar em sucessão a diferentes cultivos em pastagem degradada

Abstract

Characteristics of sugar cane varieties (density, height and plant flowering, diameter, straw removal, drying degree and stem weight, °Brix, Pol%, juice purity%, fiber%, ATR and AR) were evaluated in succession to green manure crops and soybean on degraded pasture under irrigated and rainfed systems. The experimental design was a randomized block with split plots, being tested six sugar cane varieties (RB86-7515, RB83-5486, SP81-3250, SP80-1816, RB92579 and RB85-5536) in the plot and five crops (soybean, millet, C. juncea, velvet bean and pigeon pea) plus a control (degraded pasture) in the subplot, in two environments (irrigated and rainfed) and two replications per environment. The irrigation increased the plant height and the rainfed conditions, greater stem density and better qualitative parameters. There were variations in density and plant height and little changes in the flowering and stem drying degree among varieties. The stem diameter and straw removal of the varieties were maintained. The varieties RB83-5486, SP81-3250 and RB85-5536 showed higher °Brix, Pol% cane and ATR whereas RB86-7515 and RB92579, greater yield potential. The previous cropping with C. juncea, velvet bean, pigeon pea and millet was more beneficial to quality of sugar cane varieties.