About the biological behaviour of cv. Coratina

The horticultural interest of self-compatible fruit tree cultivars depends on their ability to reach the optimal fruit set by self-pollination, thus making superfluous cross-pollination and related problems. In Apulia region (southern Italy) the olive cultivation is spread on about 370,000 hectares. ‘Coratina’ is the most popular olive cultivar in the central part of the region, where actually it is grown in solid blocks on 60,000 hectares and characterized by high and constant productivity. ‘Coratina’ is generally considered to be a self-compatible olive cultivar, but its biological behaviour is a vexed question in the scientific literature. In order to ascertain the real biological behaviour of ‘Coratina’, a 3-year study was carried out on 10 representative monovarietal olive groves scattered on the area of main diffusion. Data concerning fruit set following open-pollination and unassisted self-pollination have been gathered. Among years and sites, an optimal fruit set (3.5%) was obtained from open-pollinated branches and a scarce fruit set (0.02%) from self-pollinated ones. These results assert the self-incompatibility of ‘Coratina’ and show its capacity to provide optimal production levels thanks to the abundant and natural sources of flying compatible pollen from neighbouring districts where different cultivars are spread.