Abstract:The useful part of sandal tree (Santalum album) is the fragrant heartwood, which usually starts its formation in about 10-year-old plants and increases slowly in size with the aging of the plant. In natural condition, it will take 30-40 years for the formation o f commercially valuable hastwood in a sandal tree. In this study, 2-yeal-old seedlings of Santalum album were treated by 1% of a plant growth inhibitor (PGI-1) with different dosases (1ml, 3ml) and different frequencies (once, twice and four times per year). Plants treated with the same quantity of water and that not being treated were used as control. After three years of treatment, the plants were dug up, the stems and roots were ground into powder and distillated by steam separately. The obtained oil were measured and analysed by using gas chromatography. The results show that PGI1 has distinct effects on forcing the heartwood formation in Santalum album. The average oil contents in stems and roots, as well as the sandalol content in the oil of the plants treated by PGI-1, with very few exceptions, are much higher than that treated by water. On the other hand, the differences of oil and sandalol contents are inconspicuous between the plants treated by water and that not being treated. It shows that mechanical injury alone during treatment has little influence on the formation of heartwood in sandal tree.
