Perdas de grãos de trigo na colheita mecanizada com colhedora equipada com peneiras autonivelantes

Abstract

The harvesters have the function of removing the grains from the crop, clean, without straw or cultural residues, with the minimum of quantitative and qualitative losses. However, losses arising from the harvesting process, inherent to the machine, can be caused due to higher displacement speed, inclination and adjustment of the internal mechanisms of the harvester. So, the inclination of the harvester accentuates the losses, mainly in the cleaning system. To minimize this type of loss, automatic sieve leveling systems were developed, so that the sieves always work leveled. Thus, in this work, the objectives were to evaluate the losses in different conditions of inclination of the machine with the self-leveling sieves; grain losses when subjecting the harvester to different displacement speeds during the harvesting operation; the total losses in the harvest, with a system of self-leveling sieves. The treatments are constituted by the pre-harvest grain losses and total losses during the harvesting operation of the wheat crop at different intervals of harvester inclination (0-5%, 5-10%, 10-15%) and speeds of operation (4 km h-1, 6 km h-1, 7 km h-1). The harvester used was a New Holland® brand, model TC5070, with a self-leveling screen system and a 20-foot wide platform. The results obtained demonstrate that there is no statistical difference in grain losses, with a harvester equipped with self-leveling sieves, in the interaction between slope factors and displacement speed. The displacement speed of 7 Km h-1 during the wheat harvesting operation caused the highest grain losses. The highest grain loss as a function of machine slope occurred in the 5-10% slope range. The harvester's inclination provides a change in grain losses even when equipped with a self-leveling screen system.