苹果缺铁首先表现在上部叶,特别是顶梢叶先变绿黄,再变黄白,缺铁过甚者会使枝梢枯死。为了进一步验证,可将估计缺铁的枝梢剪下,放在0.2％的硫酸亚铁烧杯中,经50小时后,叶片中脉和近中脉的部分呈现紫色,而放入清水中的则无颜色变化,从而验证苹果缺铁。据笔者试验,苹果缺铁的综合防治措施如下。 First, the performance of iron deficiency in the upper leaves of apple, especially the top leaves change first green yellow, then change the yellow and white, iron deficiency or even make shoots dead. For further validation, the iron-deficient shoot tips may be cut and placed in a 0.2% ferrous sulfate beaker. After 50 hours, the midrib and mid-midrib sections of the leaf appear purple while those that are placed in clear water have no color Changes in order to verify Apple iron deficiency. According to my test, Apple’s comprehensive prevention and treatment of iron deficiency are as follows.