叶片失绿症是石灰性土壤上作物尤其是双子叶植物的普遍现象,在果树、蔬菜上已有大量报道[1-3];大田作物方面对花生、大豆、小麦、豌豆等研究较多[4-7],但是棉花大面积叶片失绿症状尚未见报道。2005年夏季调查发现,在新疆库尔勒地区大面积的棉田存在幼叶黄化现象,严重者叶缘带有 Leaf chlorosis is a common phenomenon in calcareous soils, especially in dicotyledonous plants. There have been many reports on fruit trees and vegetables [1-3]; more research on peanut, soybean, wheat and pea has been done on field crops [ 4-7], but a large area of ​​leaf chlorosis symptoms have not been reported. In the summer of 2005, it was found that young leaves were yellowing in a large area of ​​cotton fields in Korla region of Xinjiang. In severe cases,