THE STUDY OF THE ANATOMICAL STRUCTURE OF APPLE-TREE TISSUES AND APPLE FRUITS (MALLUS MILL.) - Ecological Consequences of Increasing Crop Productivity - page 133

FIGURE 14.4 Longitudinal radial cut of the grafting place of 'Johnagold' young tress on
rootstock M.9 depending on the grafting method: А—a 1-year-old grafting using the improved
copulation method; B—a 1-year-old grafting; C—a 2-year-old grafting.
Using a grafting method (Figure 14.4(B)), the joining of grafting components oc-
curs in a lower part of the bud (see Figure 14.1), and a leading system is formed only
on one side when we look at a longitudinal radial cut of the grafting place. A protec-
tive tissue covers a greater part of the grafting place, which is situated between its
components and in the upper part of the rootstock; it does not facilitate their reliable
growth. Water supply goes through a narrow (up to 0.5 cm) canal of leading elements
of secondary xylem and phloem. When time progresses, the area of active movement
increases (Figure 14.4(C)), and a protective tissue zone shifts to the upper part of the
young tree, being less productive as to the strength and exchange of plastic substances.
Attention should be paid to the core damage of a grafted cultivar in a 2-year-old young
tree (Figure 14.4(C)), which is not typical to a 1-year-old young tree. Probably, it is
due to a weak supply of the rootstock with plastic substances and the effect of unfavor-
able environmental conditions.
Anatomical studies of the grafting place of young apple trees of various age show
essential tissue disorganizations, especially in the xylem area, proved by several trials
[19]. Similar changes affect the growth and development of a fruit tree. Some scien-
tists [20] believe that the tissue in the grafting place has an effect on vegetative growth
of a shoot, limiting water fl ow from the root to the shoot, or by moving the substance,
particularly useful mineral substances and growth-regulating hormones (most likely
cytokinine) from transporting fl ow.