Growing a columnar apple tree on different types of rootstocks

The purpose of research is to study the influence of different types of rootstocks on the processes of growth, development and fruiting of columnar apple trees. The work was carried out in 2019-2022 as part of the municipal assignment for the implementation of the project “Testing technology for growing columnar apple trees in the Ryazan Region” at the training and experimental site of the Ryazan city station for young naturalists on gray forest soil with an average level of fertility. Seedlings of a vigorous rootstock were propagated in 2019 by seed method from apple seeds of the Antonovka variety; to obtain clonal rootstocks, standard forms of rootstocks were used: № 54118 (medium-sized) and M9 (dwarf). In the spring of 2020, the columnar apple variety Moskovskoe Ozherelie was grafted onto these types of rootstocks using the copulation method. In September 2020, grafted seedlings of each species, uniform in height and shoot diameter, were selected and planted from the nursery to the experimental plot. Each option included six plants grafted on one type of rootstock, planted in rows according to a pattern of 80 × 200. Observations of the growth and development of grafted apple tree seedlings were carried out for three years, noting the survival rate of the grafts, the condition of the upper bud of the main stem, the growth of lateral branches on the central shoot, and the appearance of fruits in the seedlings. Biometric measurements were carried out in September on all available plants, measuring the height of the plant, the number of lateral branches, and the number of fruits. It has been established that a columnar apple tree variety grafted on a dwarf rootstock has less growth of the central shoot and begins to bear fruit earlier, in contrast to the same variety grafted on medium-sized and tall rootstocks. A columnar variety grafted on tall and medium-sized rootstocks begins to form lateral shoots from the third year of vegetation, while the same variety grafted on a dwarf rootstock does not form lateral branching unless the apical bud of the shoot is damaged.