###### Abstract  
Explipiting biodiversity must be considered today an effective strategy to improve the sustainability of olive production systems. The evaluation of local cultivars, based on their vegetative and fruiting traits, along with an analysis of product quality, may contribute significantly to the development and diffusion of new olive-growing systems. The aim of this study was to evaluate growth, productivity, and olive oil quality of three Sicilian cultivars with different vigor/growth habit grown in four different combinations of training form and planting density. 'Abunara', 'Calatina', and 'Nocellara del Belice' olive trees were planted in four different intensive planting systems: \(2\times 5\) m trained to central leader (CLx2), \(3\times 5\) m trained to free palmette (FPx3), \(4\times 5\) m trained to small globe vase (GVx4), and \(5\times 5\) m trained to poly-conic vase (PVx5) and evaluated for seven years. Planting systems with low-density showed faster growth (trunk cross section area and canopy volume) than high-density systems. High-density systems had higher yield per hectare but lower yield per tree than low-density systems. 'Calatina' was the least vigorous but most productive cultivar. 'Abunara' and 'Nocellara' were relatively vigorous and suffered the tight spacings of high-density systems. Yield efficiency was generally high in 'Calatina', and it showed an increase with time in 'Abunara' and 'Nocellara' grown under the GVx4 and PVx5 systems. Fruit yield per hectare was highest in 'Calatina' grown under high-density systems. Oil yield was lower in 'Nocellara' than in 'Abunara' and 'Calatina'. In terms of oil quality, 'Calatina' and 'Abunara' produced oils with higher oleic acid content than 'Nocellara'. Generally, 'Calatina' has production characteristics of considerable interest, which, combined with low canopy volume and vigor, make it suitable for intensive pedestrian olive orchards with high levels of harvest and pruning mechanization and using different strategies and machines. Overall, for their management flexibility, these planting systems can contribute to improve sustainability of the olive industry even in sloping, dry areas of the Mediterranean. campoy volume; growth; fatty acids; intensive growing systems; _Olea europae_; phenolic compounds; pedestrian orchards; volatile compounds +
Footnote †: journal: _Horticulturae_  
and, consequently, the economical profitability of olive systems and to maintain their agro-biodiversity and environmental sustainability, tree size must be reduced. Despite the work of breeding programs to obtain new low-vigor cultivars [3; 4; 5; 6; 7; 8] and some combinations of rootstocks/cultivars adapted to hedgerow plantings [6; 7; 9], the use of dwarfing rootstocks has still not been fully achieved in olive trees [10; 11; 12]. Hence, the best and most immediate strategy for the survival of olive growing in the dry and sloping areas of the Mediterranean is going, for example, along the same lines as pedestrian fruit orchards [13; 14]. The general concept of pedestrian orchards is to use relatively low-vigor trees planted at medium to high densities (400-1000 trees/ha) to be fully managed from the ground. In olive, this setup would represent a viable solution for those areas where site and climate conditions as well as irrigation water availability limit the use of super-high-density (SHD, >1000 trees/ha) olive planting systems. Indeed, SHD olive planting systems are often unsuitable in countries such as Greece, Italy, Turkey, and Tunisia, where most of the olive groves are traditionally grown in small farms with sloping land [2; 13]. In those areas and under those conditions, pedestrian olive orchards could fill the planting density gap (300-1000 trees/ha) between traditional and SHD systems, use local cultivars that adapt well to climate and soil settings, and produce high-quality olive oils, thus representing the best and only opportunity to maintain a viable and sustainable olive industry.