在樟子松育苗生产中 ,常常出现幼苗早期封顶现象 ,影响苗木的产量和质量 ,降低经济效益。樟子松幼苗早期封顶是当幼苗长 3～6轮真叶时 ,顶端长出圆形芽苞 ,初呈绿色 ,后变褐色而停止生长。引起封顶的原因 ,根据多年观察实验主要有以下几点 :( 1)樟子松种子适宜在低温下催芽处理 Pinus sylvestris seedlings in the production, often appear early seedling cap phenomenon, affecting seedling yield and quality, reduce economic benefits. Pinus sylvestris seedlings early cap is when the seedlings grow 3 to 6 round true leaves, the top grow round buds, the beginning of green, brown and then stop growing. Causing the cause of capping, according to many years of observation experiments are the following: (1) Pinus sylvestris seeds suitable for germination at low temperatures