Whole fruit mineral element composition and quality of harvested ‘Delicious’ apples1

‘Wellspur Delicious’ apple trees received preharvest foliar sprays of CaCl2 at rates of 0, 5.9 or 19.6 kg Ca/ha. season. Fruits of uniform size (7.65 to 8.05 cm diameter) were harvested on a single date and were allowed to ripen at 19°C or were placed in controlled atmosphere storage for five months and then allowed to ripen at 19°C. Fruit quality indices were measured at various times during ripening. The CaCl2 sprays failed to influence fruit mineral element composition, skin color, soluble solids, titratable acidity, firmness, bitter pit or watercore. At all times during ripening, fruit skin color, soluble solids, titratable acidity and firmness were independent of whole fruit Ca, Mg, K, N and P concentrations, and whole fruit Mg/Ca, K/Ca, (K+Mg)/Ca, K/(Ca+Mg), N/Ca and P/Ca concentration ratios. Fruits with and without bitter pit had identical whole fruit Ca concentrations and K/Ca concentration ratios. Whole fruit mineral element composition was an insensitive predictor of quality indices of harvested ‘Delicious’ apples.