Grafting Propagation Techniques of Red Sandalwood (Pterocarpus santalinus), a Precious Hongmu Tree Species

[Objectives] This article aimed to study the grafting propagation techniques of red sandalwood (Pterocarpus santalinus), so as to provide technical support for the effective propagation of seedlings of this precious Hongmu species. [Methods] Based on the analysis and comparison of the growth performance of the Hongmu tree species introduced to China, taking 1 to 2-year-old Pterocarpus indicus seedlings as rootstocks and single-bud stems of P. santalinus as scions, grafting was carried out from January to April using three grafting propagation methods, cut grafting propagation, skin grafting propagation and oblique grafting propagation. [Results] The results of several years of experiments show that in early spring, P. santalinus could be propagated well using the grafting propagation methods of skin grafting propagation and oblique grafting propagation, with survival rate over 80%. For rootstocks with young age or thin stems, the joint unions of the oblique grafting propagation healed well, without apparent protrusions, unlike those of skin grafting propagation. The survival rate of oblique grafting propagation that is fast and reliable was higher than that of cut grafting propagation. [Conclusions] It is feasible to use the grafting propagation methods to propagate P. santalinus seedlings. This is a traditional and innovative technology path in the in the propagation of high-quality seedlings of precious Hongmu trees, and can be promoted and applied in industrial practice.