The effect of the rootstock on growth, yielding and fruit quality of three cultivars of sour cherry cultivated in the Warmia region.

The experiment was conducted in 2006-2008 in the Didactic and Experimental Garden of the University of Warmia and Mazury in Olsztyn, Poland. The research materials were sour cherry trees of the 'Kelleris 16', 'Ujfehertoi Furtos' and 'English Morello' cultivars, grafted on rootstock of Mahaleb seedling, Mazzard seedling and F12/1. The 'English Morello' cultivar grafted on the rootstock of Mahaleb seedling demonstrated the highest productivity. The same cultivar grafted on the rootstock of Mazzard seedling and F12/1, along with the 'Ujfehertoi Furtos' cultivar on Mahaleb seedling and Mazzard seedling, had the lowest productivity. The largest sour cherry fruits were recorded for the 'Ujfehertoi Furtos' cultivar. From all the cultivars examined, Mazzard seedling rootstock resulted in the largest fruit weight. A fruit quality evaluation based on their chemical composition revealed the highest content of ascorbic acid in fruits of the 'English Morello' grafted on F12/1, and the lowest value was recorded for the 'Ujfehertoi Furtos' on Mahaleb seedling. The highest sugar content was found in fruits of the 'Ujfehertoi Furtos'. Mahaleb seedling in all cultivars under examination had a favourable effect on sugar accumulation in fruits. Fruits of the 'Ujfehertoi Furtos' cultivar grafted on the Mahaleb seedling contained the highest amount of organic acids, while 'Kelleris 16' on the same rootstock and 'English Morello' on F12/1 had the lowest.