AVALIAÇÃO DE MUDAS PRÉ-BROTADAS(MPB) E GESSAGEM NA PRODUTIVIDADE DE CANA-DE-AÇÚCAR

Abstract

The objective of this study was to analyze the MBP (pre-budded seedlings) efficiency of sugarcane with different depths of planting groove under the effect of several gypsum dosages with interference on yield and juice quality at the end of the first harvest and first ratoon cycle. The experimental design was randomized blocks in a 3 x 3 factorial scheme with subdivided plots. In the plots, three agricultural gypsum concentrations (0; 7; 14 Mg ha-1) and in the subplots three sowing types: MPB transplanted in shallow pit (MPB-shallow); MPB transplanted in deep pit (MPB-deep) and conventional sett planting. Biometric analyzes (number of leaves, stems, tillers, plant height and stem diameter), soil analysis and juice quality characterization and yield analyses were performed. The results obtained from the soil analysis revealed positive effects in depth of 0.0 to 0.4m in most of the analyzed variables (K+, S-SO42-, Ca, SM, T pot., t efet., sat. base, Al3+), except pH (CaCl2), which had better results in the deeper layers (0.4 to 1.0 m) in the first harvest, evidencing that the soil (0.0 to 0.4 m) may have been acidified by the absorption of large amounts of nutrients by the roots, and in the ratoon sugarcane it was noticed in the pH analysis that it remained high in the layers of 0.6 to 1.0 m. The MPB productivity under 14 Mg ha-1 of gypsum and conventional under the same dosage obtained the best levels of POL (%), BRIX (%), but conventional sugarcane obtained higher sugar yield, 23308.92 Mg ha-1, 1.71% higher than the MPB production of 14 Mg ha-1. These treatments (MPB-deep and conventional 14 Mg ha-1), however, did not stand out in the biometric analyses during the whole cycle, an indicator that these plants assigned their phytoassimilates to accumulate sucrose, instead of biomass.