ROOTSTOCK AND BUDDING HEIGHT AFFECT SWEET CHERRY ORCHARD GROWTH

To study the effects of rootstock and budding height on tree growth, 4 cherry cultivars (‘Burlat’, ‘Van’, ‘Summit’, and `Saco’)were chip-budded in August 1997 at 10, 20, and 30 cm above ground level on Tabel Edabriz, Gisela 5, and MaxMa 14, and at 10, 30, and 60 cm on CAB 11E and mazzard. After taking initial data on nursery performance, an orchard trial was set up at three distinct climatic sites ~ 50 km apart in north-central Portugal: Bragança, Mirandela and Vila Real. Preliminary data at the end of the second year revealed treatment differences with regard to trunk girth, total stem length and number of shoots per plant, with similar effects at all three sites. Trunk girths on Tabel Edabriz, Gisela 5, MaxMa 14, and CAB 11E were, respectively, 60, 58, 85, and 78% of that on mazzard. Tree vigor varied with budding height; in general, relative trunk diameter growth was inverse to tree budding height both in the nursery and the orchard. Relative tree height tended to increase with budding height of the vigorous rootstocks, but not the dwarfing rootstocks. Of the 4 cultivars, ‘Saco’ was significantly less vigorous than the others on all of the rootstocks, which probably was due to infection with viruses. This trial will continue to evaluate treatment differences as the trees mature and cropping begins.