Several series of dwarfing rootstocks were bred in research institutes and universities all over the world in the 1960s and 1970s. These series were reviewed by Bujdosó and Hrotkó (2005). Since 1994 international cherry rootstock trials in Europe were co-ordinated by the Danish Institute of Plant and Soil Science at Aarslev, Denmark. The Research and Breeding Institute of Pomology Holovousy Ltd. has jointed these trials as one of their partners and established an experimental orchard with a range of selected cherry rootstocks in the spring of 1999 using nursery stock material that had been propagated in Aarslev. Preliminary results from the orchard study based upon the first five years of observations have been previously published (Blažková, Hlušičková 2004). This paper deals with more comprehensive results that include a stage of the full cropping of the orchard.
Material aND MethoDsFor this study, ten sweet cherry rootstocks (G 154/7, G 195/20, G 497/8, Gisela 3, Gisela 4, Gisela 7, P-HL-A, Tabel Edabriz, Weiroot 158 and Weiroot 53) were used. P-HL-A was considered as a standard (control) for all the others. As a scion cultivar Lapins (of Canadian origin) was used for all these rootstocks. For five of them, the cultivar Regina from Germany was grafted as another tester. Nursery stock of the material was grown from bench-grafted rootstocks at the Danish Institute of Plant and Soil Science at Aarslev, Denmark. It mostly consisted of two-yearold trees without ramification.The experimental orchard was established in the spring of 1999 at Holovousy. Trees were planted in three randomised blocks with three trees per each Lapins cv. -rootstock replication using a spacing of 5 × 1.5 m. In the case of Regina, only one tree per replication was planted on each tested rootstock. Climatic conditions at Holovousy are characterised by the average annual temperature of 8.1°C and the average annual rainfall of 650 mm. The soil was medium loam sandy with a rather deep cultivated layer on gravel substrate. The orchard was located at the altitude of 280 m a.s.l. and it was situated on a very gentle slope facing north. Ten clonal dwarf or semi-dwarf rootstocks were evaluated in a trial that was established in the spring of 1999 at Holovousy. Lapins cv. was used as a scion tester for all these rootstocks; five of them were tested also by Regina cv. Among the new rootstocks G 195/5 was evaluated as the most promising for Lapins cv. The highest rate of mortality and symptoms of poor scion compatibility with Lapins cv. were observed on Weiroot 53 and Weiroot 158. The most vigorous of the tested rootstock was G 497/8 followed by Gisela 7 and Gisela 4. Intermediate vigour was recorded on trees on G 154/7, P-HL-A, Gisela 3 and Tabel Edabriz. The least vigorous were G 195/20, Weiroot 158 and Weiroot 53. The highest accumulated yield per hectare of the Lapins cv. (21.2 tons) was harvested from Gisela 7 rootstock. With Lapins cv. higher yield efficiencies were calculated for P-HL-A, G 195/20 and Tabel Edabriz. In the case of the Regina cv...