Winter hardiness of apple clonal rootstocks in Southern Cisbaikalia

Abstract

The paper presents the results of a study of apple clonal rootstocks carried out in 2017-2022 in the trial plots located in the Irkutsk region. The objects of the study were clonal rootstocks from various scientific institutions. The conducted fieldwork allows us to state that the ecological conditions of the Southern Cisbaikalia are generally favorable for the use of clonal rootstocks in the regional horticulture. It was found that the most adaptive forms of all the studied clonal rootstocks are the rootstocks of the Ural selection (Ural and Ural 2) and the rootstock of the Estonian selection (E-56). The clonal rootstocks 70-6-8, Arm18, and K-2 withstood winter worst of all. According to the fieldwork results, the rest of the rootstocks showed medium winter hardiness. As a result of laboratory freezing experiments, E-56 high winter hardiness was confirmed. The study of cultivar-rootstock combinations showed good compatibility of clonal rootstocks with semi-cultivated apple trees. The variety and type of the rootstock were statistically proven to affect the degree of temperature damage to fruit trees. The clonal rootstocks with high winter hardiness and those with medium winter hardiness and high recovery ability were selected for further breeding work.