Vibrations transmitted to the whole body during citrus cultivation

This paper reports the results of some experimental tests aimed at evaluating the exposure vibration level of the tractor driver during two very common agricultural activities in citrus orchards: spraying and grass trituration. Measurements were carried out during ordinary working conditions by using a triaxial accelerometer placed on the seat of a 4-wheel drive isodiametric tractor. The sprayer was a trailed conventional one with hydraulic pulverisation and axial fan, while the grass triturator was equipped with cutting tools on 1.9 m working width. Accelerations were measured globally and during each working phase (transfer, spraying, trituration), so to evaluate its influence on the whole operator exposure.The main results showed that with both operating machines the vibration level (A(8) equal to 0.39 and 0.44 m/s2 with the grass triturator and the sprayer respectively) was lower than the daily exposure action value fixed by the 2002/44/EC directive, but this happened, especially with the sprayer, as the exposition time was shorter than the reference duration of 8 hours established by the regulation. In fact the weighted root mean square (RMS) values during the transfer from and to the farm centre with the sprayer and those during the working phase with the grass triturator exceeded 0.5 m/s2.Finally, the FFT analysis showed the influence of the ground during the forward movement of the tractor, being present harmonics at low frequency (2–3 Hz). Furthermore, the analysis evidenced the engine speed during both cultivation activities, as well the influence of the operating machines during the different working phases.