Resposta de seis variedades de cana-de-açúcar a doses de potássio no cerrado de Roraima

Abstract

Sugar cane is a crop witch exhibits advantages concerning to rusticity, capability of adaptation to the various edafoclimatic conditions, to management efforts, its good adaptation for ratoon cultivation, high yields. Selections for productive varieties, responsive to fertilization and adapted to local edafoclimatic conditions is essential for establishment of sustainable crop of sugarcane in savanna soils of Roraima. In this way, this research intended to study the performance of six sugar-cane varieties to increasing doses of potassium in the savanna of Roraima. This research was conducted in field conditions in the Centro de Ciências Agrárias, at Universidade Federal de Roraima, under Awi climate in a yellow latossol. The experimental design was completely randomized blocks, under a factorial scheme of split-plot, where each block consisted of five plots with doses of potassium (0, 80, 160, 240 and 320 Kg ha-1) and six subplots with varieties (RB72454, SP81-3250, SP79-1011, SP801816, RB867515 and RB855536) with four replicates. The parameters assessed were number of stalk per meter, average diameter of stalk, average mass of stalk, BRIX and maturation index, leaf potassium content, total productivity of stalk and industrial productivity. As conclusion, addition of potassium provided a better performance among all production parameters. Dose of 80 kg ha-1 of K2O was the most suitable for attainment of higher productivity. Varieties RB72454 and RB 867515 outstanded with the best productivities in savanna of Roraima, within present study.