1. Council for Agricultural Research and Economics, Research Centre for Olive, Fruit and Citrus Crops, 81100 Caserta, Italy
2. Department of Agricultural Sciences, University of Naples ‘Federico II’, 80055 Portici, Italy
3. Institute of Biosciences and Bioresources (IBBR), National Research Council (CNR), 80055 Portici, Italy
4. Research Institute on Terrestrial Ecosystems (IRET), National Research Council (CNR), 80100 Napoli, Italy