Seasonal variation regularity of mineral elements content in apple pear fruits

The mineral elements content in apple pear fruits was regular in a certain degree with the seasonal changes. The content of N, P, K, Ca and Mg was the highest point in the young fruit period,it reduced with fruit expansion,and reached the lowest point in the mature period.The changes of Fe and B content were great,the content of Fe and B was high in the young fruit period,it reduced the lowest point at the end of July,then it showed increasing trend with the fruit growth. The changes of Zn and Mn content were smooth,the content of Zn and Mn showed decreasing trend and it had a little increase in the late period of fruit growth. Between fruits and leaves, Ca and Mn showed significant negative correlation, but P and K showed significant positive correlation.