Relationships Between Fruit Acidity and Soluble Solids Levels of Highbush Blueberry Clones and Fruit Keeping Quality1

Fruit of 104 clones and 75 seedlings of highbush blueberries were assayed for acidity, soluble solids, and keeping quality. From this group, 9 clones were selected to represent 4 extreme soluble solids and acid classes. These 9 clones were harvested over 2 years at 2 North Carolina locations. The previously reported relationships between high fruit acidity (Ac) or low soluble solids-to-acid ratio (SS/Ac) and high keeping quality (low DK) were extended from a few cultivars to a population of representative blueberry genotypes. Approximately 80% of the decay variability can be accounted for by various soluble solids and acid measures indicating that a soluble solids and acid measure would be useful to the breeder for segregating clones into those of poor, intermediate and good keeping quality. Suggested clonal discriminatory Ac, SS/Ac and pH x SS levels were proposed, and the possibility of field screening of blueberry clones for keeping quality potential was examined.