Vegetative growth, productivity and fruit quality of 'Kordia and 'Regina' sweet cherry on different rootstocks: a six-year field evaluation

Abstract

Rootstock-scion interactions strongly influence vegetative growth, productivity and fruit quality in sweet cherry. This study assessed the effects of seven rootstocks on two sweet cherry cultivars, 'Kordia' and 'Regina', during a six-year field evaluation under the conditions of central North Macedonia. Vegetative growth was evaluated through annual shoot growth and trunk cross-sectional area (TCSA), while reproductive performance was assessed by yield per tree, cumulative yield, yield per unit area and yield efficiency. Fruit quality was determined by fruit weight, diameter, soluble solids content and titratable acidity. Gisela 5 and Gisela 6 induced the lowest vegetative growth in both cultivars, but also resulted in the highest yield efficiency and the highest yield per unit area. However, these dwarfing rootstocks were associated with reduced fruit weight and smaller fruit diameter. Mahaleb promoted the strongest vegetative growth, while the highest cumulative yield per unit area in cv. 'Kordia' was noted with Gisela 5 rootstock. This rootstock (Gisela 5) delivered the highest cumulative yield in cv. 'Regina'. Rootstocks that induced greater vigour generally produced larger fruits, while highly productive dwarfing rootstocks tended to reduce fruit size. These results highlight the importance of balancing productivity and fruit quality when selecting rootstocks for modern sweet cherry orchards. Although Gisela 5 and Gisela 6 achieved high yield efficiency and productivity per unit area, their lower fruit weight and diameter may limit their suitability where larger fruit size is required. Under conditions similar to those of the study, Mahaleb appears suitable for semi-intensive systems, while MaxMa 14 appears to be better suited for more intensified orchard systems.