Abstract: The effects of different bag treatments on the absorp tion of calcium in ‘Red Fuji’ apple fruits
were studied with ⁴⁵Ca isotopic trace technique. The results showed that the total contents of calcium in apple
fruit increased during the whole development and the main uptake occurred in the earlier and later growth sta
ges. Moreover, itwas found that the kinds of bags had significant influences on the amount of calcium up take
with the control fruit showing the highest abilities of calcium absorp tion, and the fruit covered with paper bag
had the lowest amount of calcium. On the other hand, the rate of calcium absorp tion was higher at the begin
ning of treatment, but declined graduallywith the extension of experiment time. The results also indicated that
the calcium absorbed in app le fruit entered the stem end first and then to the calyx end. It is concluded that
the calcium absorbed in app le fruitwas removable and might be moved to the shoot, leaves or other parts, sug
gesting that calcium absorbed in apple fruit canpt be re-distributed was discussible.

Key words: Apple, Fruit, Bagging, Calcium, Isotopic trace