'Regina' on three dwarf cherry rootstocks and different planting distances in Alpe Adria Region

In spring 2006 sweet cherry cultivar ʻReginaʼ was planted on Gisela 3, Gisela 5 and Weiroot 72 at three tree spacings 1.5, 2.0 and 2.5 m in several locations of Alpe Adria region in Europe. After the sixth leaf results for tree vigour, productivity and fruit weight were evaluated. Tree vigour was affected by location, rootstock and rootstock × location combination. Trees in Maribor and Sondrio were significantly more vigorous than in Zagreb and Bilje. Gisela 5 was more vigorous than Weiroot 72 and Gisela 3 was the most dwarfing rootstock. Tree distances had no significant impact on Gisela 3, but only on Gisela 5 and Weiroot 72. There were significant effects of year and rootstock × location combination on average yield and fruit weight. Average yield tree^-1, beside influence of year, was significantly affected also by rootstock × location and plant distance × location interactions. The highest tree production was obtained in Zagreb at plant distances 2.0 and 2.5 m than in Sondrio, Maribor and Bilje. Yield efficiency of ʻReginaʼ was significantly affected by rootstocks and locations. The highest fruit weight was measured from trees on Gisela 3, Gisela 5 and Weiroot 72 in Sondrio, but it did not significantly differ from fruits on Weiroot 72 in Maribor. Fruit weight was influenced also by year and tree distance: the highest values were obtained at 2.5 m and the lowest at 1.5 m.