GROWTH AND BRANCHING HABIT OF ROOTED CUTTINGS COLLECTED FROM EPICORMIC SHOOTS OF BETULA-PENDULA ROTH

Patterns of shoot growth and branching were studied over two growing s easons in rooted cuttings collected from both epicormic shoots and see dlings of Betula pendula Roth. Epicormic shoots were induced to sprout on stumps and small logs of 5-, 1 0- and 30-year-old trees. The use o f epicormic shoots enhanced the rooting capacity of stem cuttings coll ected from these shoots but did not appear to reverse the process of m aturation. In this study, maturation was based on characteristics typi cal of mature trees but not necessarily those of the mother plant, bec ause it was not possible to root cuttings, for comparison, from 5-, 10 - and 30-year-old ortets, other than from epicormic shoots. There was evidence of the persistence of mature characteristics through an incre ase in shoot plagiotropism with increasing ortet age. Rooted cuttings from both seedlings and epicormic shoots, however, assumed an increasi ngly orthotropic habit with a smaller shoot angle at the end of the fi rst growing season than at the beginning and this continued into the s econd growing season. Other indications of maturation, such as delayed bud flushing and the incidence of flowering with increasing ortet age , were also evident in rooted cuttings from epicormic shoots. There wa s a clear difference in branching habit depending on cutting source. R ooted cuttings derived from epicormic shoots produced nearly twice as many lateral branches compared with rooted cuttings collected from see dlings, but this was not an effect of maturation. There was some evide nce that rooted cuttings derived from seedlings grew taller than roote d cuttings from epicormic shoots.