Fig. 4. Longitudinal changes in the functionality of xylem in (A–C) ‘Braeburn’ and (D–F) ‘Granny Smith’, assessed at 160 and 163 DAFB, respectively. Each point represents the means dye level for the primary, dorsal and ventral vascular bundles falling within the same fractional distance between ‘0’ (near the stalk end) and ‘10’ (near the calyx end) of the fruit. Vertical bars represent s.e.