To the issue of correlation between temperature and phenology of Padus avium Mill

Biological low - inherent to a plant indicator of the temperature at which it begins its active development. Based on the biological value of low culture, the calculated amount of active and effective temperatures needed by the plants at different stages of seasonal development. Relative to the minimum temperature required for development of the bird cherry the literature provides different data. Performed in the analysis showed that the variability of the sums of temperatures at the time of the phenophases bird cherry, calculated from 0°C, lower than the sums of temperatures, calculated from 5°C (effective), that can be considered as more accurately reflecting the needs of the bird cherry in the warmth and take biological minimum for bird cherry a temperature of 0°C.