果树缺铁症其主要表现是失绿,是我国果树生产中的大问题,在西北、华北和黄河故道果区的许多果园中、苹果树、梨树、桃树缺铁失绿现象均十分严重。据调查,失绿果树与同龄健树比较,产量下降19～47%,且树势弱,抗逆性差,死亡早。1986年中国农科院果树所与西南交大机械系合作研制强力树干注射机,并进行强力树干注射铁肥 The main manifestation of iron deficiency in fruit trees is chlorosis, which is a big problem in the production of fruit trees in our country. In many orchards of fruit trees in Northwest, North China and the old course of the Yellow River, the iron deficiency and chlorosis of apple trees, pear trees and peaches are very serious . According to the survey, the loss of green fruit trees compared with the same age-matched trees, the output decreased by 19 ~ 47%, and the tree weak, poor resistance, early death. In 1986, Chinese Academy of Agricultural Sciences, fruit trees and Southwest Jiaotong University Department of Mechanical cooperation in the development of powerful trunk injection machine, and a strong trunk injection of iron fertilizer