Résumé
Arboricultural practices such as pruning, artificial bending or fruit thinning are crucial interventions in orchard management and are used for controlling tree size, penetration of light into the canopy and the equilibrium between vegetative and reproductive growth. The aim of this project is to explore the possibility of integrating such practices in a model of apple tree development. To this end we designed field experiments to study the effects of pruning (thinning or heading cuts) on two apple cultivars with contrasted architecture, 'Fuji' and 'Braeburn'. The results of these first experiments showed that the cultivars had significantly different reactions to pruning: 'Braeburn' trees showed a greater reduction in the total number of internodes compared to 'Fuji' trees, despite the fact that a greater number of internodes developed on 'Braeburn' trees. Thinning cuts of laterals tended to be compensated by an increase in lateral branching. Results also indicated that trees which had been pruned tended to develop trunks with similar number of internodes as control trees (which were not pruned). These experiments constitute a first step for assessing the rules underlying tree responses to pruning, which will be further integrated into a model of growth.