Abstract
Spring and summer pruning are based on the possibility to manipulate the physiological control of axillary sylleptic growth and carbon allocation in the shoot through alteration of the apical dominance and light distribution in the canopy. The practical result in modern orchards is a higher flower bud differentiation for apricot and an easier training system maintenance for peach with more efficient use of labor. Cultivated apricot varieties show diverse tree architectures, habit and fruiting branches. The effect of pruning intensity at different times during spring and summer seasons is specific for the singular growth habits. Differences among the peach varieties are less evident than in the apricot. The ease with which peach water sprouts produce axillary sylleptic shoots makes the use of mechanical topping possible in the first two years of intense growth in order to train the tree as a bush and then to open it as a vase with manual pruning (Catalonian open vase). In all modern peach orchards, pruning in late summer results very useful to obtain a better light distribution in the canopy and a more efficient carbon allocation to fruiting shoots, preventing and reducing the need for winter pruning.
