The photosynthetic surface area of apple trees

Abstract

The development of stem and leaf surface areas were studied comparatively throughout a year’s cycle, and the proportions of these areas within the total area of trees were calculated. Depending on the variety, the total surface areas of trees: All branches, boughs and tree trunks after winter pruning, ranged from 27 dm2 to 118 dm2. At the beginning of the vegetation season, the proportion of leaves in newly developed stems amounted to 90%–92%, and the proportion of these new stems was 8%–10%. Later in the vegetation season, the leaf area amounted to 83%–89%, and that of new stems 11%–17%, and there were no differences between the varieties. Towards the end of the vegetation season, total leaf area on a tree ranged from 110–120 dm2 to 296 dm2, whereas the area of newly grown stems ranged from 42 dm2 to 168 dm2. In the course of the vegetation season, the proportion of the stem area decreased while that of leaves increased, and from August onwards the leaf area exceeded that of stems in the majority of the studied varieties. In the final part of the vegetation season, the leaf area was higher than area of stems, by over 20%–45%.