Proper selection of rootstock that is adapted to local growing conditions and climate is one of the most important preconditions for obtaining high yield in intensive plum orchards. The aim of the investigation was to evaluate the influence of different rootstocks on the productivity of two plum cultivars: ‘Kubanskaya Kometa’ (Prunus rossica. Erem.) and ‘Victoria’ (P. domestica L.) in different climatic conditions. The following sixteen rootstocks known in Europe were used in the trial: eight vegetatively propagated (‘St. Julien A’, ‘Brompton’, ‘Ackermann’, ‘Pixy’, ‘GF 8/1’, ‘G 5/22’, ‘GF 655/2’, ‘Hamyra’) and eight generatively propagated (‘St. Julien INRA2’, ‘St. Julien d’Orleans’, ‘St. Julien Noir’, ‘Brompton’, ‘Wangenheims Zwetsche’, ‘St. Julien Wädenswil’, ‘Myrobalan’, P. cerasifera var. divaricata). The evaluation was made in experimental orchards in Latvia, Estonia and Belarus. Orchards were established in spring 2001. Trees were planted at spacing 3 × 5 m in four replications, three trees per plot. The data obtained in years 2008-2015 are presented. The yield was influenced by rootstock and differed between years, growing regions and cultivars. The meteorological conditions during wintering period had significant influence on yield for trees on all evaluated rootstocks.

The aim of the investigation is to evaluate the influence of different rootstocks on the flowering intensity of two plum cultivars: a hybrid `Kubanskaya Kometa` and European plum ‘Victoria’ in diverse locations. Sixteen well known European rootstocks were used, of which eight were clonal (St. Julien A, Brompton, Ackermann, Pixy, GF8/1, G5/22, GF655/2, Hamyra) and eight were seedlings (St. Julien INRA2, St. Julien d Orleans, St. Julien Noir, Brompton, Wangenheims Zwetche, St. Julien Wädenswil, Myrobalan, P. cerasifera var. divaricata). The evaluation was conducted in experimental orchards which were established in spring 2001 in Latvia, Estonia and Belarus. Trees were planted at a spacing of 5 × 3 m in four replications, three trees per plot. The obtained data from the years 2008-2012 are presented. The flowering intensity of plum trees depended on the cultivar rootstock combination. The influence of rootstock on flowering intensity differed between the years and growing region, and was closely correlates with meteorological conditions during the wintering period. Cv. ‘Kometa Kubanskaya’ had the highest blooming intensity in Pûre on rootstocks GF 655/2 and Wangenheims Zwetche; in Brest on Brompton seedlings, Julien d’ Orleans G5/22 and Ackermann; and in Polli on GF 8/1 and Brompton seedlings. ‘Victoria’ plum trees had the highest intensity of flowering on rootstocks Pixy and Wangenheims Zwetche in Pūre; on St. Julien INRA 2 and Ackermann in Brest; and on GF 655/2 and Ackermann in Polli.

Methodological recommendations for lighting modes for growing rootstocks and varieties of domestic plum at the stages of micro propagation, in vitro rooting and ex vitro adaptation determine the usage of lamps with different light spectra, allowing to obtain more higher results of micro clonal propagation, including: the height of regenerated plants and the number of leaves, the propagation ratio; development of the root system; growth and physiological state at the stage of ex vitro adaptation.

The research was carried out in 2019–2020 in the laboratory of the fruit-growing department of RUЕ “Brest regional agricultural experimental station of the National Academy of Science of Belarus”. The objects of research were microplants of in vitro zoned rootstocks VPK-1, Saint Julien GF 655/2 and microplants of domestic plum varieties Vengerka Belorusskaya, Venera, Empress. Studies have shown that at the stage of proliferation a high propagation coefficient was achieved at the second passage of Empress variety, when illuminated by the spectrum “red, blue, infrared, ultraviolet” (4.7±1.17) and in “control” (4.3±0.32). On fourth passage of cultivation when illuminated by the spectrum “red, blue, infrared, ultraviolet” Empress’s variety propagation coefficient is 5.4±0.17. When illuminated by the spectrum “red, blue, infrared, ultraviolet” the average shoot length was the longest for the Vengerka Belorusskaya variety (4.5±0.68 сm), by “full spectrum” was the best variant for the Venera variety (3.3±0.34 cm). When evaluating the number of leaves on the shoot, the advantage of the “full spectrum” lamp for the Vengerka Belorusskaya variety (16.4±0.68 pcs) is noted.