Phenological stages of Macadamia integrifolia x tetraphylla cv Beaumont according to the BBCH scale in a Mediterranean climate

The macadamia nut (Macadamia integrifolia Maiden and Betche, Macadamia tetraphylla L. and their hybrids) are increasingly cultivated outside its native range in subtropical eastern Australia, where it thrives in specific climatic conditions. Given its expansion into diverse climates, particularly Mediterranean regions, understanding macadamia’s phenological response to non-native conditions has become essential. This study examines the adaptability of M. integrifolia x tetraphylla cv. ‘Beaumont’ within the Mediterranean environment of northwest Sicily, Italy. Focusing on phenological phases, we applied the BBCH scale to categorize growth stages from vegetative bud initiation to fruit ripening. Field observations and measurements over 16 months revealed that macadamia phenology in Sicily exhibits distinct responses to Mediterranean temperature and precipitation patterns, affecting growth stages such as leaf development, flowering, and fruit maturation. The phenological data, standardized via the BBCH scale, provide valuable insights for agronomic management, aiming to optimizing yields and adapting cultivation practices. These findings offer essential guidance for macadamia cultivation in similar environments and underscore the importance of phenological monitoring in managing climaterelated risks to productivity and yield stability.