Phenology, Yield and Nut Traits Evaluation of Twelve European Hazelnut Cultivars Grown in Central Italy

Abstract

European hazelnut (Corylus avellana L.) cultivation has grown worldwide in recent years, even though the world’s production is still fulfilled by a few dozen cultivars well adapted to the local environments of their selection. After Turkey, Italy is the second largest producer of hazelnuts, and the province of Viterbo, in central Italy, is recognized as one of the most suitable districts for hazelnut cultivation. The production in this area relies almost entirely on local cultivar ‘Tonda Gentile Romana’, whereas cultivar ‘Nocchione’ is used as the main pollinizer. More recently, cultivar ‘Tonda di Giffoni’ has been introduced in new local plantations. Cultivation of many cultivars in different areas is of fundamental importance to test their adaptability to different environmental conditions, a need currently accentuated by ongoing climate change. With this aim, a European hazelnut collection field was established in 2000 in Caprarola municipality (Viterbo province), where plants of twelve hazelnut cultivars were observed over four growing seasons for their phenological, agronomic and nut traits. The cultivars studied, namely ‘Barcelona’, ‘Camponica’, ‘Ennis’, ‘Merveille de Bollwiller’, ‘Negret’, ‘Nocchione’, ‘Riccia di Talanico’, ‘San Giovanni’, ‘Tombul’, ‘Tonda di Giffoni’, ‘Tonda Gentile’ and ‘Tonda Gentile Romana’, showed a high diversity in their phenological behaviour, yield efficiency and nut and kernel traits. Cultivars ‘Negret’, ‘Tombul’ and ‘Tonda Gentile’, with poor yields over the years of research, do not seem suitable to be cultivated as main cultivars in the studied environment, contrary to ‘Camponica’ and ‘San Giovanni’, which produced abundantly, reaching a total of almost 30 and 25 kg plant—1 of in–shell hazelnuts, respectively. Cultivars ‘Tonda Gentile Romana’ and ‘Nocchione’ confirmed their yield consistency, whereas ‘Ennis’, ‘Barcelona’ and ‘Tombul’ seem suitable to be introduced as pollinizers thanks to their male blooming overlapping with the female blooming of the main cultivar ‘Tonda Gentile Romana’. Cultivar ‘Tonda di Giffoni’ did not perform well in the studied environment, despite being recognized as one of the highest-yield cultivars.