Tree vigour, cropping, and phenology of sweet cherries in two systems of tree training on dwarf rootstocks

Five cultivars and four rootstocks (Gisela 5, P-HL-A, P-HL-B, and Tabel Edabriz) were evaluated on trees in fruiting stage trained like spindle and on trellis. Tree vigour was significantly related to cultivar, rootstock and to tree training. Spindles were generally more vigorous than trees on trellis with exception of cv. Kordia. In several cases special combinations of cultivar, rootstock, and method of tree training differed significantly from mean effects of the three factors. Time of flowering was significantly dependent on the cultivar and varied annually within 15 days. Time of fruit harvest was also influenced by the rootstock and in two cases mutually contradictory to the tree training method. Yields per tree were generally dependent on the cultivar. With Burlat and cv. Kordia rootstock and tree training were also important. Higher specific yields were recorded on trellis-trained trees. Remarkable in this respect were Vanda and trees of Summit on P-HL-B and Starking Hardy Giant on Tabel Edabriz. Higher specific yields on spindle had Kordia on P-HL-A and Tabel Edabriz and Burlat on P-HL-A. Mean values of annual yields per hectare in spindle ranged between 10.0 to 17.5 t whereas in trellis between 6.7 to 12.3 t. The absolute highest annual yield (35.7 t) was recorded on spindle trees of Kordia on P-HL-A. In trellis the highest yield of 27.1 t had Kordia on Gisela 5. The advantage of spindle over trellis was greater in Burlat and Kordia but much lower in cv. Vanda. Fruit size mainly depended on the year. Only two rootstocks influenced fruit size differently in some years. Training system had no effect on fruit size.