GROWTH AND MORPHOGENESIS IN THE CANADIAN FOREST SPECIES: VII. PROGRESS AND CONTROL OF LONGITUDINAL GROWTH OF BRANCHES IN PINUS RESINOSA AIT.

The course of longitudinal growth of branches of red pine was followed through weekly measurements, and analyzed in relation to position in the crown, season, site, and spacing. Certain observations were also made on the effects of age of the tree, root or branch pruning, and the application of growth regulators. The growth of branches is essentially like that of the main axis, but quantitatively is highly dependent on position in the crown. The pattern of growth appears to be more closely related to fluctuating environmental conditions than to qualities inherent in the individual tree. The length of the growing season is relatively stable, while the rate of growth is widely variable and dependent on the immediate environment.