Evaluation of new nectarine cultivars for growing in the Crimea

As a result of years of hybridization of introduced nectarine cultivars, new domestic cultivars were created in the Nikita Botanical Gardens. This paper presents the main biological properties of 5 nectarine cultivars: ‘Rubinovyiy 4’, ‘Rubinovyiy 7’, ‘Suvenir Nikitskiy’, ‘Evpatoriyskiy’, ‘Ishunskiy’. The researches were conducted in 2004-2016 in the Nikita Botanical Gardens, Yalta, Russian Federation. All trees were at the same age and received the same standard cultural practices. We used an open vase peach pruning system. As a control cultivar ‘Stark Sunglo’ was chosen. The study objects were phenological, pomological characteristics, and fruit chemical composition of 5 new cultivars, bred in the Nikita Botanical Gardens. The phenological observations were: start and end of flowering, date of fruit ripening. Pomological observations were performed on 10 fruits randomly harvested at maturity: weight, fruit shape, skin color (ground color, blush, and blush type), flesh color, texture, and stone characteristics. In this research dry matter, monosaccharides, total sugars, ascorbic acid, titratable acids, leuco-anthocyanins, water-soluble pectin, and protopectin were also determined. ‘Ishunskiy’ was marked out by the highest content of dry matter (18.8%), total sugars (14.2%), leuco-anthocyanins (250 mg 100 g^‑1), and amount of pectin substances (1.44%). ‘Evpatoriyskiy’ had the highest content of ascorbic acid (19.7 mg 100 g^‑1). The best taste qualities were observed in ‘Ishunskiy’ and ‘Evpatoriyskiy’. The largest average weight and latest flowering period were observed in ‘Rubinovyiy 4’. As a result of our breeding program, the new nectarine cultivars (‘Rubinovyiy 4’, ‘Rubinovyiy 7’, ‘Suvenir Nikitskiy’, ‘Evpatoriyskiy’, ‘Ishunskiy’) were handed for state registration.