By labelling leaves of fruiting shoots with 13CO2 when fruit reached 30% and 80% of the final size (703 and 708 BBCH, respectively), leaves and fruits enriched in 13C 4 and 7 days after labelling (Fig. 3A and B) indicating both appreciable fixation of 13CO2 and its transport to the fruit. Nevertheless, enrichment of 13C was not observed in the bark tissues of scaffold branches supporting labelled fruiting shoots or in the roots. Fruit sampled four days after labelling showed a slightly smaller 13C enrichment compared to fruit sampled 3 days later, regardless of its developmental stage at labelling. On the contrary, in leaves, greater 13C enrichment was found for the former compared to the latter, particularly for leaves labelled at 708 BBCH stage (Fig. 3A and B). When leaves were labelled at the fruit change colour or at full ripeness (801 and 809 BBCH, respectively) 13C was already detected in the bark tissues of branches supporting labelled fruiting shoots regardless of labelling time and sample date indicating that C movement occurred across the tree (Fig. 3C and D); furthermore, 15 days after labelling small 13C enrichment was detected in the growing branched lateral roots (∂13C = 5–6) regardless of labelling time. In these two cases, i.e. during colour development, fruit was not as strongly enriched in 13C as it was during the active fruit growth period (703 and 708 BBCH), particularly when leaves of fruiting shoots were labelled at growth stage 809 BBCH-scale ( Fig. 3D). In all cases, the increasing fruit ∂13C from 4 to 7 days after feeding paralleled the decreasing leaf ∂13C. Same results were obtained for adult (15-year-old) trees, but only results for young trees are presented.