怎样防治小棚韭菜缺素症缺素症是一般老茬韭菜普遍发生的一种生理性病害。常见的有：缺铁症、缺硼症、缺铜症三种。一、缺铁症缺铁症在低洼潮湿和盐碱含量较高的板结地块发病较重（新老茬韭菜没有差异）。出苗后１０天左右开始出现症状。发病时叶片失绿，呈鲜黄色或淡白色... How to prevent the shed shed leftover deficiency disease is generally a common old crop chickens a physiological disease. Common are: iron deficiency, boron deficiency, lack of copper three. First, the iron deficiency iron deficiency disease in the low-lying damp and salty alkali content of plate land mass heavier (no distinction between new and old leeks). About 10 days after emergence began to appear symptoms. When the incidence of chlorosis leaves, was bright yellow or pale white ...