海滨盐碱地，黄河故道沙荒地栽培梨树易缺铁，发生黄叶病（又名失绿病）。表现为叶片黄白色，叶脉仍保持绿色，旺盛生长期症状显著；开始部分枝条发病，逐渐全株发病，严重时新梢顶端叶片枯焦，影响树势，降低产量；壮树不发病或少发病。施硫酸亚铁可暂时纠正，但不能根治。发 Coastal saline land, the old course of the Yellow River sand pear cultivation easy iron deficiency, the occurrence of yellow leaf disease (aka chlorosis). The performance of the leaves yellow-white, veins remain green, strong symptoms of vigorous growth period; beginning part of the branches of the disease, the gradual whole plant disease, severe top shoots of young shoots, affecting the tree vigor and reduce production; Ferrous sulfate can be temporarily corrected, but can not cure. hair