First Evaluations on Vegetative and Productive Performance of Many Hazelnut Cultivars in Latium Region

In the Latium Region (Italy), hazelnut crop production is almost exclusively obtained from the cultivar 'Tonda Gentile Romana'. This is a paradigmatic case in Italy, where a narrow genetic background is at the base for a nut crop. Therefore, the vulnerability to biotic and abiotic stresses for hazelnut orchards could be extremely high. With the aim to extend the hazelnut genetic basis in Latium, during the year 2000 a collection field was established in a vocated hazelnut-growing area, at Le Cese surrounding the basin of Vico Lake, in Viterbo province. The collection consists of 48 cultivars managed with standard orchard management techniques. Vegetative and productive performances of each cultivar were observed over the period of 2008-2011. The cultivars 'Hynich', 'Pallagrossa' and 'Montebello' showed a very low suckers emission, suggesting their use as rootstocks no-suckers emitter. The higher yield at the first cropping years were found in 'Camponica', 'Nociara', 'San Giovanni', 'Barrettona' and 'Carrello', whereas the higher percent kernel was observed in the cultivars 'Tombul', 'Cosford' and 'Daviana'. High variability among cultivars was also observed for the characters vigour, yield efficiency and blooming. Data reported in this work will be useful to select cultivars suitable for a varietal turnover in the older hazelnut orchards of Latium Region that need to be renewed.