Telehandler for mechanical pruning of hazelnuts

Italy has the largest surface cultivated with hazelnut (Corylus avellana L.) in European Union and is the second word largest producer of this dry fruit after Turkey. Italian agro-food industry is the world leading consumer in hazelnut. Hazelnuts are largely cultivated in middle (Campania, Lazio) and north (Piemonte) of Italy. During the last decade the surface cultivated with hazelnut has grown 10%, mostly in hilly not irrigate area of northern Italy where has positive economical results in comparison with alternative crops. Plantation is subsidised by the local measure of the agricultural European policy. In new plantations and principal businesses harvesting, the most labour demanding, soil management, pesticides and fertilizers application are carried mechanically. Pruning is hand made. It requires 20-30 hours of labour for hectare, depending on the variety and the number of plants for hectare. It is the second most important operation in term of hour of labour for hectare. Pruning is important to preserve quantity and quality of yield for the duration of cultivation. 10-20% of the aerial mass of the plants is cut off the plants, increasing sunlight penetration into the plant stimulating the production of new branches. Cost of labour and difficulties in finding people for this operation made some of the major business to make recourse to mechanical pruning. It is carried out with an apparatus consisting of a series of rotating blades mounted vertically on a frame to be carried and powered by tractors. Mechanical pruning requires 1/2-1/4 of the time of the hand made operation. First results of this technique, when it is applied on plants grown with specific canopy, do not show negative results from the economic point of view, considering costs and production. This paper reports the technical solutions adopted to equip a telehandler with a cutting apparatus for the hazelnut pruning. Telehandlers are self-propelled machines that find application in agriculture for their highly flexibility and capacity of lifting and handling, generally fitted with hydrostatic transmission and high performance hydraulic system. The pruning apparatus consist of 2 series of rotating blades fixed on 2 frames coupled to the front of the telescopic boom with simple mechanism. The 2 series of blades are powered by the hydraulic power system and can change the vertical inclination for "hedging" and "topping" operations. Hand acted controls in the cab give driver complete power over the pruning apparatus with particular attention for safety of operator and use.