Apical dominance.

Axillary buds usually do not grow due to apical dominance: release of auxin by apical meristems.

  • Auxin from the apical bud inhibits the growth of axillary buds.
  • If the apical bud is removed, cytokinins, produced in roots, stimulates the growth of axillary buds and lateral branches.
  • Applying auxin to the stump suppresses growth of the lateral branches, indicating both hormones play a role in determining lateral growth.