F. Santos, A.P. Silva, A. Santos
Manual harvesting is the most limiting operational handicap for the expansion of hazelnut cropping in Portugal, but importing equipment is not a realistic alternative because it is very expensive and is not adapted to Portuguese hazelnut orchards. In an attempt to overcome this shortcoming, a small-sized and low-cost equipment is being developed for mechanical harvesting and two others were prepared for calibration and shelling, all within the scope of an AGRO 162 project called “Yield increase of hazelnut crops in Portugal”. The hazelnut harvesting equipment is composed of a hopper, a four-stroke engine, a ventilator, two flexible tubes for conveying the draw-in material and a wheelbarrow required to drive the assemblage. The calibrator is built with three iron sieves mounted in a sloping position to allow the hazelnuts to roll. The shelling equipment is essentially made of a metallic roll driven by an electrical engine, with two rulers, positioned in accordance with the generating roll, that compress the hazelnuts against a wood ruler. The distance between the roll and the wood ruler can be adjusted. The trials on hazelnut harvesting allowed us to obtain a work rate of between 23 to 40 h/ha, depending on the conditions of the test. The calibrator was designed to obtain four different lot sizes. The shelling equipment performances depended greatly on the size of the lot, the best results being obtained with the biggest hazelnuts. To summarise it can be stated that this harvesting equipment is a reasonable solution for low acreage orchards, where a low work rate is allowed, due to its low price. The shelling equipment provides a good percentage of shelled hazelnuts in the upper lots, but in the lower ones it is necessary to do more than one shelling operation; this limitation can be reduced with the incorporation of more sieves to get more lots of small hazelnuts.
Santos, F., Silva, A.P. and Santos, A. (2005). HAZELNUT COLLECTION, CALIBRATION AND SHELLING. Acta Hortic. 686, 359-364
DOI: 10.17660/ActaHortic.2005.686.50
hazelnut, orchard, harvester, calibration, shelling

Acta Horticulturae