PRELIMINARY RESULTS OF A GERMAN SWEET CHERRY ROOTSTOCK TRIAL

The goal of this national trial was to identify rootstocks suitable for dwarf sweet cherry tree cultivation. Some new rootstock selections were grafted with two standard cultivars ('Hedelfinger' and 'Regina') and tested at several sites. The results at the respective locations were compiled for a common evaluation. The trial was planned by the national working group for fruit extension. Data collection and trial leadership was carried out by the State instructional and experimental station Oppenheim. After common propagation, the trees were planted at 9 locations (Bavendorf, Dresden, Müncheberg, Oppenheim, Veitshöchheim, Witzenhausen, and partly at Weinsberg, Jork, and Randwijk/NL). The trial began in 1996 and is expected to conclude in 2004. The trial design consists of 6 trees per treatment in 2 replications with a plant spacing of 4.5 m x 2.5 m. The treatments are divided into 2 groups: rootstocks with and without additional irrigation. Throughout 2001, only 2 of the 6 compared locations exhibited no mortality, which was influenced by location, cultivar and rootstock. Rootstocks with high mortality rates were ‘GiSelA 4’, ‘Gisela 497/8’, ‘Damil’, ‘Gisela 195/20’ and ‘Weiroot 158’. Less than 5% was obtained with ‘Tabel’ and ‘Piku 3’, ‘Piku 1’, ‘GiSelA 5’ and ‘GiSelA 318/17’. With respect to productivity, the highest levels were achieved with ‘Tabel’, ‘GiSelA 5’ and ‘GiSelA 195/20’. Low productivity was observed in ‘Piku 3’, ’Damil’ and ‘Weiroot 158’. Except for ‘GiSelA 4’, ‘Weiroot 158’ and ‘Damil’, the vegetative performance of the rootstocks looks more homogenous than the reproductive performance. The highest level was found with the rootstocks ‘Piku 3’, and the lowest with ‘Tabel’. Most rootstocks were positioned at a middle level around ‘GiSelA 5’.