RELATIONSHIP BETWEEN SURFACE COLOR AND OTHER MATURITY INDEXES IN WILDLOWBUSH BLUEBERRIES

The surface color, size, and sugar, titratable acid and anthocyanin co ntents were measured on samples of various maturities from 72 individu al lowbush blueberry clones to determine the relationships between sur face color and other ripeness indicators. Among the total 504 berries, the maximum sugar content was approximately 5 times that of the minim um, while the maximum titratable acid and anthocyanin contents were 20 and 11 times those of the minimum contents, respectively. Correlation s among variates were generally strongest for samples within clones, a nd they were weakest among the variate means for the 72 clones. For th e total 504 berries, sugar content correlated more strongly with surfa ce color than with berry size, while acid content correlated similarly with surface color and size. Correlations (positive or negative) amon g berry size and sugar and titratable acid contents did not exceed 0.6 0. Principal component analysis, which was used to identify groupings of correlated variates, indicated coordinated changes in berry charact eristics during ripening, lower sugar and anthocyanin concentrations i n large berries, and substantial interclonal variation in wild blueber ries. Clonal selections obtained from an experimental trial differed s ignificantly in all the variates measured, while wild clones without a surface bloom were not different from those clones with bloom.