52 Secondary shoots and epicormics
Secondary shoots and epicormics are used synonymously and are defined as shoots that have developed from dormant buds on the stem or on branches. In some cases, old epicormics can be difficult to separate from branches.
In some species, the development of secondary shoots is the normal part of crown formation. For example, in Picea abies, secondary shoots develop along the main branches to replace older shoots that have lost their needles. In other species, particularly broadleaves, the development of epicormic shoots in the crown and on the stem may reflect increased levels of light penetration through the foliage of the outer crown.
Scoring of the presence of shoots reveals whether the tree is responding to loss of foliage and thus the regenerative capacity of the tree.
For example, a heavily defoliated Picea abies that has no secondary shoots is indicative of a tree under extreme stress.
Separate assessments are made of the frequency of epicormics in the assessable crown and on the stem.
The assessment must include all epicormics, not only the ones of the current year.