Productivity of sweet cherry cultivars on Gisela 5 rootstock.

The paper presents the elements of productivity of sweet cherry cultivars grown in the region of Sabac in the period of four years (2008-2011). We examined 16 relatively new cultivars: ‘Chelan’, ‘Cristalina’, ‘Early Lory’, ‘Early Star’, ‘Glacier’, ‘Kordia’, ‘Noir de Meched’, ‘Penny’, ‘Regina’, ‘Skeena’, ‘Summer Sun’, ‘Summit’, ‘Sunburst’, ‘Sylvia’, ‘Tehranivee’, and ‘Vandalay’. The control cultivar for comparison was ‘Van’. All cultivars are grafted on the Gisela 5 rootstock. Training system is Slender Spindle, and tree spacing is 4 x 1.5 m. Studies have included: number of flowers in an inflorescence, fruit set, fruit weight, yield per tree, and cumulative yield efficiency. The average number of flowers per inflorescence varied from 2.08 in cultivar ‘Skeena’ to 3.17 in cultivar ‘Cristalina’. Fruit set ranged from 23.1% (‘Summit’) to 62.8% (‘Glacier’). Four cultivars had significantly higher fruit set than the control (‘Van’) and they are: ‘Glacier’, ‘Vandalay’, ‘Summer Sun’, and ‘Regina’. Fruit weight was lowest in cultivar ‘Vandalay’ (5.8 g), and highest in cultivar ‘Penny’ (10.2 g). Significantly higher fruit weight than the control had eight cultivars (‘Penny’, ‘Summit’, ‘Cristalina’, ‘Noir de Meched’, ‘Sunburst’, ‘Kordia’, ‘Skeena’, and ‘Sylvia’), while significantly lower fruit weight was found only in one cultivar (‘Vandalay’). The average yield per tree was lowest in cultivar ‘Skeena’ (2.68 kg), and highest in ‘Regina’ (7.38 kg). Significantly higher yield than control cultivar had only ‘Regina’, while lower yield had five cultivars (‘Skeena’, ‘Noir de Meched’, ‘Tehranivee’, ‘Sylvia’, and ‘Summit’). Cumulative yield efficiency varied from 0.23 to 0.66 kg cm-2 of trunk cross-sectional area. This parameter was at the level of control in three cultivars (‘Sunburst’, ‘Glacier’, and ‘Regina’), while in other cultivars it was significantly lower.