INFLUENCE OF DIFFERENT OLIVE ROOTSTOCKS ON GROWTH AND YIELD OF THE 'ARBEQUINA IRTA-I 18^®' CLONE

An olive rootstock selection program has been established in order to identify genotypes appropriate for reducing tree (scion) vigour using grafting. Additional rootstock characteristics which have been considered are tolerance to specific soil diseases and adaptability to different soil conditions. A critical current problem for the new super high density (SHD) system is the lack of both low vigour cultivars and dwarfing rootstocks. The ‘Arbequina’ cultivar is the most widely used cultivar in the hedgerow system. However, reduction in vigour would contribute to better orchard management. The ‘Arbequina IRTA-i•18^®’ clone was grown on two root systems, own-rooted and grafted onto eleven clonal rootstocks. Preliminary results have shown that some rootstocks have a strong influence on scion vigour and yield. The lowest tree vigour was observed in ‘Arbosana’, ‘Corbella’ and ‘Limoncillo’ rootstocks, while ‘Menya’, ‘Fs-17’ and ‘Joanenca’ were the most vigorous scions. Concerning fruit characteristics, the rootstocks had little influence on the cultivar so far. Thus, at present ‘Arbosana’ and ‘Limoncillo’ seem to be the preferred rootstocks to reduce the vigour of ‘Arbequina-i•18^®’ cultivar because they promote higher productivity (kg/cm²) for this clone. These rootstocks are a potential choice for establishing a super-high density orchard.