发展苹果无病毒苗木势在必行目前，苹果病毒病害已成为危及当前苹果生产的严重问题，据河北省农林科学院昌黎果树研究所调查．带毒病株树势衰弱．生长量减少４０％至６０％，产量下降１６％至６０％，品质变劣，抗逆性差。苹果的病毒病害多达３０余种。危害苹果的病毒可以... The development of apple virus-free seedlings is imperative At present, the apple virus disease has become a serious problem that endangers the current apple production, according to Changli Fruit Research Institute of Hebei Academy of Agriculture and Forestry. Poisonous strains of trees weak. Decrease in growth by 40% to 60%, decrease in yield by 16% to 60%, poor quality and poor resistance. Apple virus disease up to more than 30 species. Viruses that harm Apple can ...