据报导,我国西北、华北等地区,有的果园苹果,梨黄叶病的发生比较严重,产量和产品品质均受到影响。关于这种由于缺铁诱致的生理病害问题,曾引起了许多研究者的重视,但用硫酸亚铁来防治黄叶病的效果并不令人满意。我们过去在果树生长期,采用土壤施用硫酸亚铁溶液浸根;或硫酸亚铁与有机肥混合施用,防治效果良好,但有时出 It is reported that in some areas of Northwest China and North China, some orchards of apple trees and pear-leaf blight occur more seriously, and the yield and product quality are affected. Concerned about this physiological deficiency caused by iron deficiency has attracted the attention of many researchers, but the use of ferrous sulfate to control the effect of yellow leaf disease is not satisfactory. In the past, we used the soil to apply ferrous sulphate solution to soak roots during the growing season of fruit trees; or the ferrous sulphate and organic fertilizer mixed and applied, the control effect is good, but sometimes