Form defects

1. Main stem sinuosity

This phenomenon due to a very active growth may occur very early during the extension of the young stem.

2. Apical mortality

Either the bud, the distal part of the stem or the entire growth unit can die . Factors involved in this death have to be checked but frost seems not to be concerned ; summer drought, insects or other diseases may be a best hypothesis. Mostoften, apical mortality is followed by the transformation of a lateral shoot which forms a relay axis and becomes the new main stem .

3. Lateral shoot growth

The development of a branch can compete with the trunk until replacing it. In some other cases, lateral bud can expand during apical bud rest. This phenomenon appears more frequently at the end of the growing season (September or October). In very few cases this phenomenon can lead to a competition between the main stem and lateral shoots .

4. Particular branching behaviour

In case of polycyclism, the last edified growth units of an annual shoot can be very short so that the two last tiers of branches are very closed together . In this case, an abrupt decrease of the main stem diameter above the branches insertion takes place. A similar consequence occurs if lateral axes develop (case 3) during apical bud rest : in this case these lateral axes may bear branches very near the trunk.

5. Human activity !

At plantation, foresters put tree shelters around young trees in order to protect them against game. If the meshes are too large, the stems (the trunk as well as the lateral axes) may go through and so became tortuous. Growth and apical dominance are disturbed and the young tree becomes bushy. Later the base of the trunk will present large scars and a bad form.