Understanding the factors affecting within-tree variation in soluble solids concentration in peaches and nectarines
Consistent fruit size and high soluble solids concentration (SSC) in peaches and nectarines are important components of fruit quality and consumer acceptability. At harvest, differences in size between fruit within a tree can be greater than 100 g, and SSC can vary by as much as 5-10% w/w, even in well managed commercial orchards. The causes of variation in fruit quality are complex and yet to be fully determined. In this paper, we discuss the influence of physiological, environmental and anatomical factors on variation in fruit size and SSC within trees. Experimental data from recent orchard trials and histological studies conducted on commercial nectarine cultivars demonstrate the specific effects of these factors on fruit quality. Variation in SSC between fruit within a tree was found to be influenced by differences in fruit sink efficiency as determined by local carbohydrate availability, relative sink size of competing fruit (i.e., cell number), sink activity (i.e., developmental stage and fruit temperature), and differences in cell size distribution within mesocarp tissue. An empirical model based on these factors and their interactions during fruit growth may explain much of the variation in fruit quality normally found in commercial peach and nectarine trees.
Lopresti, J., Goodwin, I., Stefanelli, D., Holford, P., McGlasson, B. and Golding, J. (2016). Understanding the factors affecting within-tree variation in soluble solids concentration in peaches and nectarines. Acta Hortic. 1130, 249-256
Prunus persica (L.) Batsch, source-sink, fruit quality, fruit variability, sink efficiency, mesocarp histology