Biotic and abiotic factors limiting the productivity of Prunus cerasifera subsp. macrocarpa (Ehrh.) Erem. et Garcov.

To increase the economic efficiency of the horticultural industry, it is necessary to introduce high-yielding cultivars and considering scientific grounds for their placement in specific soil and climatic conditions. The aim of the presented research was to identify biotic and abiotic environmental factors that significantly affect the productivity of large-fruited cherry plum trees (Prunus cerasifera subsp. macrocarpa (Ehrh.) Erem. et Garcov.) of the Crimea. The studies were carried out according to generally accepted methods. The results of the long-term research of weather and climate factors on the plants’ productivity of the cultivars 'Obilnaya' and 'Rumyanaya Zorka' in the steppe Crimea are presented. It was determined that the main factors limiting productivity in both cultivars are: flowering intensity and minimum air temperature during flowering. The most significant dependence of productivity from these factors were found for cherry plum ‘Obilnaya’. Moreover, this cultivar has a closer dependence (r=0.53*, r=0.64*, respectively) than the ‘Rumyanaya Zorka’ cultivar. The most adapted to the conditions of the Crimean steppe zone was cultivar ‘Rumyanaya Zorka’. A significant factor limiting large-fruited cherry plum cultivation is spring frosts. Thus, we studied the frost resistance of generative buds of 45 promising breeding forms in the field and by freezing in a climatic chamber. Among the promising breeding forms, five are distinguished by high frost resistance of generative buds: ‘91-151’, ‘6/65а’, ‘90-213’, ‘8/27’, ‘90-249’. According to the complex of adaptive traits, two promising breeding forms were selected: ‘15-85’ and ‘17/28’. They are the sources of this character and can be used in further breeding and production testing.