Effect of excessive copper on growth and metabolism of apple trees

Excessive copper in the soil will hinder the extension of young apple branches, decrease the content of active iron and Chlorophyll significantly in the leaves, and decline the activity of catalase in young apple leaves. While the content of copper in the soil is less than a certain degree, the copper content in the leaves increases together with that in the soil, but while more than the degree the content of copper in the leaves hardly rise any longer. Adding Ca and Fe to the soil can decrease copper content in apple leaves, then excessive copper will do less damage to apple trees.