TRENDS IN APPLE TRAINING IN FRANCE - AN ARCHITECTURAL AND ECOPHYSIOLOGICAL PERSPECTIVE

Vertical Axis, Solaxe and now Centrifugal Training systems are considered to be the main stages of apple tree training over the last three decades in France. These improvements in training and pruning procedures adapted to high-density planting systems were based on improved knowledge of (1) architectural characteristics of cultivars (e.g. ‘fruiting types’), and (2) reaction of the tree to manipula¬tion (root system, pruning, bending). In this paper, we will focus on the transition from Solaxe to Centrifugal Training. In both cases, the tree is composed of a trunk around which branches are regularly spaced, with shoot bending if necessary instead of renewal pruning to control tree growth. In the latter system, ‘artificial extinction’, i.e., the complete removal of fruiting laterals at a young stage and especially around the trunk and at the bottom of branches, is emphasized. It has been shown that these procedures increase fruit size and the proportion of terminal flowering on the bourse-shoot, resulting in the enhancement of return bloom at the level of each individual spur. These results will be discussed from the viewpoints of tree architecture (e.g. tree reaction to the type of pruning used) and ecophysiology (e.g. influence of training and pruning procedures on the light climate), and in the more general context of sustainable fruit tree growing.