Study on the Application of RPA in Aerial Seeding

The seeds of Pinus tabulaeformis and Platycladus orientalis were dressed with special repellents(RPA), and the germination and growth test were conducted indoor. The results are as follows: (1) The germination rates of Pinus tabulaeformis and Platycladus orientalis seeds treated by RPA with 3 concentrations raised by 13.9% 29.8% and 24.6% 27.0%. (2) The height increment of the two tree species increased by 9.9% 19.4% and 29.4% 58.5%. (3) The stocking percentage raised by 18.5% 36.0% and 24.0% 27.5%. At the same time, the root growth was also promoted by RPA. After treatment, the root growth of the two species increased by 34.6% 50.5% and 13.9% 36.1%, respectively. Applying in aerial seeding, RPA can increase the preservation rate of seedling. The seedling amount and height are 0.5 stem/m2 and 3 5 cm while that of the CK is 0.07 stem/m2 and 2 3 cm respectively. The results of test show that RPA can increase the preservation rate, promote the root growth and lignification of seedlings and make the nursery stock over winter.