Noise Level of an Agricultural Tractor in Natural Rubber Harvesting

The rubber tree is the world’s main source of natural latex. However, the latex extraction and harvesting system requires a high level of human labor with agricultural tractors, which can expose workers to adverse conditions, such as noise. This study focused on evaluating the noise level emitted by an agricultural tractor during rubber harvesting at different operating points and working speeds. The experimental design adopted was completely randomized in a two-factor factorial arrangement with six replications. The treatments consisted of two tractor engine speeds (900 and 1500 rpm) and two workstation positions (worker inside the tractor and inside the transport trailer) during the latex coagulate collection. For the harvesting operations, a Massey Ferguson model 265 tractor coupled with a transport trailer noise exposure were used during the following operations: 1—distribution of boxes between the rows of rubber trees; 2—loading of the boxes with the collected coagulate; 3—transport of the boxes with latex coagulate to the storage location for commercialization; 4—unloading of the boxes at the storage location for commercialization. Noise assessments were performed at the workers’ ear level using a decibel meter according to technical standards. The workers’ positions and the tractor’s engine speed influenced the noise level during latex coagulate harvesting. The highest noise levels were observed when the agricultural tractor operated at a higher engine speed (1500 rpm), compared to 900 rpm engine speed. Regarding the workstation position, it was found that the noise level at the tractor operator’s station was higher than the noise level at the trailer workers’ station in all harvesting operations.