嫁接是苹果育苗的主要方法之一。苗木根和茎的交界处——根颈,在秋季最迟进入休眠,春季又最早脱离休眠,对外界环境条件的变化比较敏感。若苗木定植过深,则易产生根出条;定植太浅,苗木的固地性能差,而且根茎部位易产生冻害。所 Grafting is one of the main methods of apple seedling. Seedling roots and stem junction - root neck, the latest fall into sleep in the spring, the earliest spring from sleep, the external environmental conditions are more sensitive to changes. If the seedlings planted too deep, it is easy to produce root out; planting too shallow, seedling solid performance is poor, but easy to produce rhizome damage. The