INFLUENCE OF ROOTSTOCKS ON GROWTH AND YIELD PARAMETERS OF THE ‘GALA’ AND ‘RED JONAPRINCE’ VARIETIES [VLIV PODNOŽÍ NA RŮSTOVÉ A VÝNOSOVÉ PARAMETRY U ODRŮD ‘GALA’ A ‘RED JONAPRINCE’]

In 2017–2023, a rootstock trial was conducted at VŠÚO Holovousy with apple varieties ‘Gala’ and ‘Red Jonaprince’ grafted onto rootstocks of the Geneva series – G11, G16, G41 and clones of rootstock M9 – T337, Pajam1, Pajam2, RN29, Fl56. Total yield, yield efficiency, average fruit weight, trunk cross-sectional area (TCSA) and tree crown volume were evaluated during the experiment. The highest cumulative yield for ‘Gala’ was recorded on rootstock G41, where there was a significant difference compared to the other rootstocks, while the lowest value in this parameter was measured on rootstock Pajam1. The highest yield efficiency calculated as cumulative yield to TCSA and to tree crown volume for this variety was found on rootstocks G41 and G11. The lowest value for yield efficiency to TCSA was recorded on rootstock G16 and for yield efficiency to crown volume on rootstocks Fl56 and Pajam2. The average fruit weight for the cultivar ‘Gala’ was the highest on rootstock G41 and the lowest on G16. For growth parameters on the same cultivar, the highest values for TCSA were measured on rootstocks RN29 and G41, and for tree crown volume on Pajam2 and RN29. On the other hand, the lowest values for TCSA were measured on rootstocks Pajam1, Fl56 and G11, and again for tree crown volume on Pajam1. For the cultivar ‘Red Jonaprince’, the highest cumulative yield was found on rootstock G11, which was significantly higher than on rootstock Pajam1, which had the lowest values. The cumulative yield for the same cultivar, either to TCSA or to tree crown volume, was found to be the highest on rootstocks G11 and G41, the lowest values for this parameter converted to TCSA were measured on rootstock T337, and to tree crown volume on Pajam1. The average fruit weight of 'Red Jonaprince' was the highest on rootstock RN29, and the lowest on G16. RN29 showed the best growth values for both TCSA and tree crown volume, while the lowest values for both parameters were obtained by the rootstock Pajam1 for ‘Red Jonaprince’ variety.