我场土地属滨海盐碱地,锌盐常转化为难溶性状态,不易被苹果树吸收利用,故出现缺锌症状——小叶病。此病在我场及附近几个生产队里常表现局部枝条发病,整株发病的较少。为节省用药,我们于1976年和77年5月初分别用4％和5％的硫酸锌溶液涂 My field is a coastal saline land, zinc often transformed into insoluble state, difficult to be absorbed by the apple tree, it appears zinc deficiency symptoms - lobular disease. The disease in my field and in the vicinity of several production teams often show the occurrence of local branches, less incidence of whole plant. In order to save medication, we used 4% and 5% zinc sulfate solution in 1976 and early May, respectively.