Damage to several olive cultivars by two over-the-row harvesters in high-density orchards

The damage induced by two over-the-row harvesters was studied in several olive cultivars in two high-density orchards (1250 trees ha(-1)) in central Italy. A self-propelled harvester was used on 14 cultivars ('Arbequina', 'Ascolana Dura', 'Carboncella', 'Coroncina', 'Lea', 'Leccio Corno', 'Maurino', 'Mignola', 'Nostrale Di Rigali', 'Piantone di Mogliano', 'Piantone di Falerone', 'Raggia', 'Rosciola' and 'Rosciola Colli Esini') in a 4-year-old olive orchard, and a tow-behind harvester was used on 10 cultivars ('Arbequina', 'Ascolana tenera', 'Don Carlo (R)', 'FS17 (R)', 'Maurino', 'Piantone di Falerone', 'Piantone di Mogliano', 'Rosciola', 'Sargano di Fermo' and 'Tosca (R)') in a 5-year-old olive orchard. Trees were pruned into a conical shape from planting by removing inter-row branches that were too long and to create a continuous slender hedge. The bark damage and limb breakages were monitored in 20 homogeneous trees per cultivar after harvest. Among the local cultivars, 'Maurino' and 'Piantone di Mogliano' appeared to be highly suitable for mechanical harvest and comparable with 'Arbequina'. For other cultivars, such as 'Piantone di Falerone', the initial suitability declined as the trees aged, indicating the need to evaluate plant flexibility over time. The number of branches per tree and the longitudinal diameter of the canopy were better predictors of bark and limb damage. The most vigorous and dense cultivars were most susceptible to damage. These results provide crucial information on the adaptability of local, national and international olive cultivars to high-density planting and their suitability for over-the-row harvesting.