Anthocyanin variation in individual 'Shiraz' berries as affected by exposure and position on the rachis

This study was done on 'Shiraz'/Richter 99 grapes with the intention to define the variation of skin anthocyanin content in a single berry. The effects of berry position (on the rachis), berry exposure, berry weight category, part of the skin of a single berry, and their interactions, were analysed. The anthocyanin concentration of externally facing berries decreased and that of the internally facing berries increased from the apical part to the basal part of the bunch. Highest values were recorded in internally facing berries and lowest values in the externally facing (exposed) berries, of the basal rachis area. Anthocyanin values of small berries seemed to decrease from the apical part of…