Losses in the mechanized harvest of sugarcane as a function of working speed and rotation of the primary extractor

Resumo

Sugarcane (Saccharum spp.) stands out as one of the main crops of Brazilian agribusiness. Currently, the crop harvesting process is predominantly mechanized. The objective was to evaluate the losses and impurities in the mechanized harvest of sugarcane as a function of working speed and rotation of the primary extractor. The experiment was conducted in a sugarcane harvested without previous burning, using the variety CTC 15 in its first cutting stage, classified as upright. The row spacing was 1.5 m and the average crop yield was 92.5 Mg ha^-1. A single-row harvester was used, operating at three working speeds, being V1 (3.0 km h^-1), V2 (5.0 km h^-1) and V3 (7.0 km h^-1). Two rotations of the primary extractor were used, R1 (700 rpm) and R2 (1000 rpm). In the experi­ment, the loss of raw material and the vegetable impurities were evaluated shortly after the harvester went through the experimental area. With the highest rotation of the primary extractor, there were average levels of vegetable impurities (4 to 6%), and with the lowest rotation, there were high levels (> 7%). Levels for plant losses were low (< 2.5%) for all evaluated treatments.