Variability in size and soluble solids concentration in peaches and nectarines

Consistent fruit size and high soluble solids concentration (SSC) in peach and nectarine (Prunus persica (L.) Batsch) are important components of fruit quality. Variation in fruit size and dry matter content, within a tree and within individual branches, has been related to heterogeneity in light interception, fruit proximity to carbohydrate sources, fruit load, and interfruit competition. Causes of variation in SSC within a tree are less well understood, although they are to some extent related to differences in carbohydrate supply and fruit developmental stage. Previous research has investigated source-sink relationships affecting dry matter accumulation, without clearly establishing how dry matter is partitioned between and within individual fruits.