ASSESSMENT OF THE WINTER HARDINESS OF THE CHERRY TREES REPRODUCTIVE BUDS IN FIELD CONDITIONS

Abstract

This article presents the results of two years of research on the degree of resistance of generative buds of sour cherry varieties to adverse winter conditions in the field. The obtained results allow us to say that almost all the examined varieties were characterized by an increased degree of winter hardiness. The overwhelming majority of varieties, selected and elite seedlings were included in the first group of resistance by winter hardiness of generative buds, since their average percentage of damage to the buds by frost did not exceed 10% in two years. A few more varieties were assigned to the second resistance group and had damage at the level of 10-25%. Some varieties were assigned to the third and fourth categories of winter hardiness (25-50% and 50-75%, respectively). In the last, fifth group, in which the varieties with damage to flower buds at the level of 75-100% should be located, not one of the studied varieties was assigned. The studies were carried out at the experimental fields of the RRIFCB laboratory of breeding and cultivar studying of stone fruits. For study, 8 varieties and 4 selective and elite forms of cherry 2011 planting and 11 varieties 2015 planting were taken as objects of study. The degree of damage to the buds and tissues was assessed in the second decade of March 2018 - 2019 after the completion of the growth of 1 ... 2-year-old branches as the stage of passage of dangerous frosts was completed. Freezing of wood and core was assessed visually under a magnifying glass on cross sections of shoots according to the intensity of browning of tissues (from light to dark brown) with scores from 0 to 5.