Résumé
Apricot cultivars are characterized by a specific geographic and climatic area and when they grow anywhere else, their production decrease drastically. Such a behavior was described as a consequence of high flower bud drop, numerous flower anomalies, irregularities in floral induction and differentiation. Some authors have also mentioned that tree morphology was affected by location. The present study was based on the assumption of a relationship between the vegetative growth and the flowering potential. Tree architecture was analyzed in different growing areas and growth patterns were compared. Four cultivars were studied (SEO, Orangered, Fantasme and Bergeron) grafted on the same rootstock (Manicot) in the three main apricot production areas in France: North Rhône valley (INRA Gotheron, Valence), South Rhône valley (INRA Melgueil, Montpellier) and Roussillon (SICA Centrex, Torreilles). Architectural descriptions were done yearly and annual shoots were described by the length of their different growth units and top/bottom diameters. In 2001, we focused in the spatial and seasonal distribution of the shoots that kept growing and in the shoot diameter increments. The first results pointed out differences in the organization of the annual shoot according to the geographic area. Primary and secondary growth rhythmicity were affected by the growing area as well as the balance between growing and resting shoots along the limb. The increase in vegetative growth associated with an earlier increase in diameter increments are discussed in terms of their involving in the decrease of the flowering potential in the case of unfruitfulness