PRELIMINARY OBSERVATIONS ON THE EFFECTS OF RENEWAL PRUNING IN HAZELNUT ORCHARDS

50% of hazelnut production in the Langhe area of Piedmont is based on the cultivation of old bushes, the majority being grown as bushes or even as bushed vase. In this area hazelnut pruning is not carried out on a regular basis and orchards are therefore often overgrown. Bushes only provide significant yields in the most favourably exposed parts of their canopies. In two hazelnut orchards in the Langue, rejuvenation pruning was carried out on lots of 24-48 bushes, 18 and 20 years-old, bushed vase trained with 4-5 branches. Pruning was carried out in February and involved cutting away all branches at 1.3-1.6 m above ground level. The following parameters were evaluated over the two years following pruning: canopy volume, yield, and the commercial and technological characteristics of the nuts. Surveys revealed some recovery in production from the second year onwards, while fruit quality always improved with pruning. Results also showed that the species benefited from increasing canopy exposure to light, and that new fruit-bearing branches produced nuts with improved qualitative characteristics, with respect to the requirements of the hazelnut processing industry.