一、徒长徒长是蔬菜育苗期常见的一种生理障害。其特征是:茎细弱、节间长、叶片薄、叶色淡绿、组织柔嫩、根系不发达;定植后缓苗慢、成 First, leggy growth is a common vegetable nursery physiological disorder. The utility model is characterized in that: the stems are thin, the internodes are long, the leaves are thin, the leaves are light green, the tissues are tender, and the root system is underdeveloped;