Telepenko Y. Adaptive potential and productivity of blackberries (Rubus subg. Eubatus Focke) in the conditions of the right-bank part of the Western Forest-Steppe of Ukraine

In the dissertation it was represented, summarized and substantiated the results of experimental studies of blackberries` adaptive potential to the conditions of the right-bank part of the western forest-steppe of Ukraine. There were investigated 25 varieties of blackberries (2 of them - Ukrainian origin, the rest - introduced). The study of phenological phases showed that the blackberry plants of all studied varieties had a late blooming period, which reduced the risks of flowers` damaging with the late spring frosts. The most resistible to temperatures of -25 and -30 °C, were such varieties as Sadove Chudo, Orkan and Kiowa; varieties Ouachita and Čačanska Bestrna have been determined as resistant to temperature -25 °C. It was found, that blackberry varieties with climbing canes had less frost-resistant than semi climbing or upright forms. Natchez, Orkan, Loch Tay and Chief Joseph varieties were determined as high drought ones, characterized by high level of water retention capacity, high water content of leaves and lower water deficit. Varieties Tornfree, Asterina, Čačanska Bestrna, Chester and Heaven Can Wait demonstrated the highest yields. Early ripened varieties Loch Tay and Brzezina were characterized as plants with the highest economic evaluation of blackberry growing. There were studied features of bush habit, canes growth, functional status of blackberry leaf apparatus in the annual cycle of growth and development and it was substantiated their influence on winter hardiness which was one of the main limiting factors of blackberry growing. According to the results of the dissertation, there were found varieties with high adaptive capacity, which were recommended for the further variety trials and for involving to breeding programs as sources of valuable traits. Economic evaluation of the efficiency of blackberry growing confirmed the prospect and profitability of this crop.