根据山东省果树研究所姜秀英同志撰文介绍,苹果树缺锌会发生小叶病,致使果品产量减少,品质下降。用硫酸锌可防治此病,但施药时期对防治效果影响甚大,有的在苹果树发芽前喷药,有的(国外)在休眠期,防治效果皆不理想。近年,中国农科院果树研 According to an article by Comrade Jiang Xiuying of the Fruit Tree Research Institute of Shandong Province, leaf blight occurs in zinc deficient apple trees, resulting in a decrease in fruit yield and a decrease in quality. With zinc sulfate can prevent and cure the disease, but the spraying period has a great effect on the prevention and treatment effect, and some spraying before the apple tree germination, and some (foreign) in the dormant period, the control effect is not ideal. In recent years, Chinese Academy of Agricultural Sciences fruit research