Branch Elongation and Formation of New Stem Units as Influenced by Reductions in Leaf Photosynthetic Capacity
2019
Kidombo, Shannon D | Dean, Thomas J.
Leaf area is the primary site for photosynthesis in plants and therefore has a controlling effect on tree growth. Elongation of shoots and formation of stem units on stressed branches were investigated using a series of defoliation and shade treatments. The initial diameter and length of the branch in addition to the modifying effect of treatments on leaf area were used to assess elongation of the terminal bud. Results indicate that elongation of branch terminal shoots was significantly reduced by defoliation or shading of previous years’ foliage. The number of new fascicles in the second year of growth after treatment application was also significantly affected by the loss of previous years’ leaf area. However, shoots of all treated branches elongated and developed a new leaf area, emphasizing the ability of branches to recover from minor effects of defoliation and shade stress. The number of new stem units formed in the terminal bud of the second year was related to the shoot length of the growth cycle.
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