Effectiveness of Artificial Agarwood Resin Formation in Gyrinops Walla Using Traditional Methods

Abstract

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Certain members of Genera Aquilaria, Gyrinops, Gonystylus and Aetoxylon of Thymelaeaceae family produce a highly valuable resin inside the stem called agarwood.lt is used for perfume manufacturing, burning aroma for cultural and religious activities in many countries of the world. Gyrinops walla is the only agarwood producing member present in Sri Lanka belongs to this family. Formation of agarwoodin the tree stem isbelieve to be due to a defense mechanism against the causal agents, either environmental stress or disease. Natural formation of agarwood is rare and low in content. Therefore, the present study was aimed at identifying the best artificial inoculation methods that can induce agarwood formation in G. walla. The selected methods are practiced for Aquilaria species in Northeast Asian region covering all types of inoculations.This study tested, chemical, mechanical and biological methodsjinserting iron nails, galvanized tubes, polyvinyl chloride tubes and polypropylenetubeswere used as mechanical method and sodium chloride and sodium bi-carbonatewereused as chemicals. Forest mushroom myceliawasused as the biological method to induce agarwood formation.Medium size G. walla tress grown in Kalawana and Mathugama in the wet zone of Sri Lanka were selected to test these methods. Five replicates were used for each treatment which were applied in spiral manner on the tree stem. Agarwood formed tissues were extracted 12 months after the inoculation and resins of these tissues were collected by solvent extraction. Colours of both resinous tissues and extracted resins were determined using Munsell colour chat. Aroma produced when burning the resinous tissues was detected by a sensory panel. Significance of resin contents among different inoculation treatments were tested using One-way ANOVA.According to the results, the highest mean resin content (4.38%) was recorded from the trees inoculated with sodium chloride and the lowest mean was recorded from the trees inoculated with forest mushroom mycelia (2.16%).One-way ANOVA showed a significant difference of resin content between different artificial methods. Colours of both resinous tissues and extracted resins varied from brown to very dark brown. All treatments produced an aromatic agarwood scent which is unique to G. wallawben burning wood samples. Finally, out of the selected methods, it was revealed that addition of sodium chlorideisthe best method that can be used to induce agarwood resin formation in G. walla.