The research aimed to study the productivity of blackberry foreign varieties (Rubus subgenus Rubus Watson) in the Right-Bank Forest-Steppe part of Ukraine as they are attractive for production due to their fruit taste and
appearance. The task was to establish the beginning and duration of fruiting of blackberry varieties, to determine the yield level and the quality of the berries. A fi eld experiment was conducted on the experimental fi eld of the Scientific and Research Center of BNAU to assess the productivity of blackberry varieties. The studies were started in the spring of 2017 on blackberry seedlings with growing the culture in vitro in the biotechnological laboratory of the university. The tests included 5 varieties with climbing shoots: Smoothstem, Thornfree, Black Satin, Triple Crown, Arapaho. According to the results of observations, it was found that for two years of fruiting among the studied varieties, the earliest production was received in the Arapaho variety, in the first decade of July. Triple Crown, with the fi rst fruits ripened on August 2, was characterized by late fruiting. The Triple Crown variety diff ered by the longest period of berry coming – 35 days. The yield obtained in a year after planting is not an indicator of long-term crop yields. However, the Triple Crown variety diff ered by the highest yield in the fi rst year of fruiting, with an average of 3.7 kg of berries obtained from а bush. High yields were also observed in the Smoothstem variety. Black Satin variety was characterized by the high level of yield growth for over two years of fruiting, which amounted to 80 %. The largest in the fi rst years of fruiting were Triple Crown fruits with an average weight of 11.1 g. The maximum weight of individual berries of this variety reached 17.7 g. The Arapaho variety also stood out with its large fruits of 8.5 g on average. Some fruits reached a maximum weight of 12.1 g.
Key words: blackberry, the beginning of fruiting, productivity, average weight of berries, duration of products supply.