INTRODUCTION OF NEW BERBERIS THUNBERGII DC. CULTIVARS IN FOREST-STEPPE ALTAI

In forest-steppe Altai conditions, there were assessed winter-hardness, time of vegetation beginning, first leaf appearance as well as flowering and foliage coloring for six introduced cultivars of Berberis thunbergii DC.: ʻAdmirationʼ, ʻBagatelleʼ, ʻOrange Dreamʼ, ʻRose Glowʼ, ʻRosy Rocketʼ, and ‘Tiny Goldʼ. The paper gives characteristics of the most adapted cultivars. All Berberis thunbergii DC. cultivars had different damage levels, from 2 to 7 points, in all years of observation regardless of winter conditions. ʻBagatelleʼ and ‘Rosy Rocketʼ cultivars are found to be the most winter-resistant, ‘Orange Dreamʼ, ʻRose Glowʼ, and ʻTiny Goldʼ cultivars are moderately resistant, while ʻAdmirationʼ cultivar is the most unstable (the cultivar was deleted from the collection). Despite of winter damages, Berberis thunbergii DC. cultivars have shown a high ornamental effect. All cultivars except ʻAdmirationʼ are preliminary recommended for using in Altai region conditions.