Perdas das frações de cana-de-açúcar submetida a diversos métodos de colheita

Abstract

The effects of harvesting methods were evaluated on losses and damage in sugarcane after harvesting. The IAC86-2480 cultivar was evaluated, in its third cut, in November, 2006. Three herbage harvesting methods were evaluated: manual cutting, mechanical cutting using a harvester and mechanical followed by manual cutting. After harvesting, the material was weighed and separated into fractions of stalks, green leaves and straw. The damage under sugarcane ratoons was evaluated by counting of the number of damaged stalks, uprooted stalks and whole plants left on the central lines of the plot. Treatments were assigned to experimental units (136.5 m2) according to a complete randomized block design, with six replications. The harvested yield and total biomass available were 80.7 t/ha and 90.3 t, respectively (average data). The total losses were higher for the mechanical followed by manual cutting as herbage harvesting method, representing 18.5% of the total harvested biomass. However, when compared on a DM basis, there were no differences among herbage harvesting methods. The quantitative and relative losses of green leaves and straw were similar among herbage harvesting methods. There was difference among herbage harvesting methods for stalk fraction, showing relative loss values of 1.5% for manual cutting, 7.6% for mechanical cutting, and 12.7% for mechanical followed by manual cutting, in relation to the harvested yield. The number of damaged and uprooted stalks was higher for mechanical followed by manual cutting as herbage harvesting method. The mechanical method significantly increased the number of plants left in the field. Due to the lower losses generated by the mechanical cutting using a harvester followed by manual cutting (up to 8% on DM basis) than the manual method, the performance of the mechanical harvesting method (with or without manual cutting after arvesting) is considered satisfactory. © 2009 Sociedade Brasileira de Zootecnia.