Field and laboratory investigations of clonal rootstocks in South Cisbaikal

The study of the possibility of using low-growing clonal rootstocks in the conditions of the South Сisbaikal, the territory most suitable for horticulture in the Irkutsk region, was the goal of this work. The studies were carried out in 2017-2022 on experimental plots, which are located in the Irkutsk district of the Irkutsk region and on the territory of SIPPB SB RAS (Irkutsk). Assembled collection was included: six varieties of clonal rootstocks bred by MichGAU (62-396, 54-118, 70-20-20, 70-6-8, 64-143, 62-223), stock bred by A.P. Apoyan (Armenian RIVWFG) (Arm18), rootstock of Estonian selection (E56), eight rootstocks of Orenburg ESHV selection (Ural, Ural2, Ural5, 18-7, B-3-4, 4-12, 8-2, OB), rootstock Crimean OSH (K-2). The conducted field observations allow us to state that clonal rootstocks can be used in horticulture in the South Сisbaikal. We found out that of all the studied clonal rootstocks, the rootstocks of the Ural selection Ural and Ural 2 and the rootstock of the Estonian selection E-56 showed high winter hardiness. We attributed clonal rootstocks 70-6-8, Arm18, K-2 to low winter-hardiness. The rest of the rootstocks over the years of research showed an average winter hardiness. The results of laboratory studies confirmed the high winter hardiness of E-56. The study of cultivar-rootstock combinations showed good compatibility of clonal rootstocks with semi-cultivated apple trees: strong fusion of the rootstock with the scion, active growth, well-developed leaf apparatus, the absence of any signs of starvation and discoloration. It has been statistically proven that the variety and type of rootstock affect the degree of temperature damage to the fruit tree. Highly winter-hardy clonal rootstocks and medium-hardy clonal rootstocks with high regenerative capacity were selected as promising for breeding.

apple tree, clonal rootstock, field winter hardiness, laboratory tests