油菜从移栽到开春常出现僵苗现象,据调查,各地均有不同程度的发生,但以洼地、瘦地、水田、重茬田最为普遍和严重。从发僵程度看,轻度僵苗表现出叶速度缓慢;中度僵苗表现生长停滞;重度僵苗表现植株萎缩甚至死亡,即使不死,开春后返青慢,早苔早花,枝少、角小、粒轻,减产3—5%。从僵苗的原因上一般分为以下几个类型: Rape often appears stiff seedling phenomenon from transplanting to opening spring, according to the survey, all over the place have different degrees of occurrence, but in depression, thin land, paddy field, heavy cropland is the most common and serious. From the degree of stiff, mild stiff seedlings showed slow leaf velocity; moderate stiff seedlings showed stagnant growth; Severe stiff seedlings showed plant shrinkage or even death, even if not dead, turn green after the spring, slow, premature early flowers, branches less angle Small, light grain, cut 3-5%. From the reason of stiff Miao generally divided into the following types: