Sprouts seasonal elongation of two olive cultivars in a high-density orchard

The new high-density cropping systems (> 1,200 trees ha-1) represent a very interesting proposal for olive orchard profitability. It is crucial to know the morphology and the dynamics of sprout elongation of a cultivar in order to fully assess its suitability for a high-density olive orchard. For this reason we planned a research on two cultivars, Coratina and Arbequina, in a high-density or-chard. The apical sprouts elongation of Arbequina early stopped at fruit set without a further step, while Coratina showed a little growth flux after pit hardening. Similar trends showed the lateral proleptic sprouts. Only the sylleptic sprouts of both cultivars had a second period of activity. In all cases, the sprouts elongation finished at the end of summer, when oil accumulation started. Co-ratina showed higher apical shoot growth and internodes mean length than Arbequina. On the contrary, Coratina showed lower lateral proleptic shoot growth and nodes number than Arbe-quina, but the same internodes mean length. No significant differences were observed between cultivars for growth, nodes number and internodes mean length of sylleptic shoots. The differ-ences observed between the two cultivars could be explained considering their different vigour. The introduction of this innovative cropping system allowed to register a considerable reduction of production costs. The result is a considerable increase in the economic performance of the olive grove and a consequent reduction in the unit cost for kg of oil. These data are very useful for varietal choice and field management in high-density orchards and then for new olive breeding programs.