**4.1.2 Cultivation of rootstock**

The stem node near the surface of soil is often chose for graft site by the way of side-plug when grafting, so it is first assured that stem of rootstock is thick enough to prevent splitting of stem while the scion is inserting the hole of rootstock. In order to increase the stem diameter of rootstock, some necessary methods such as ahead of sowing or cutting off the main stem are generally adopted.
