A research team of the Central Botanical Garden has studied the physiological characteristics of the tree in a scientific way and founded out a rational open-air grafting method to easily multiply it in any place of the country.

The method has already been applied to various parts of the country and recently even to Kanggye City, Jagang Province and other northern inlands with low temperature and unfavorable conditions of growth.

It ensures a high rate of rooting and a good harvest of fruits.