Treatment Techniques to Stimulate Incensed Resinous Wood Formation of Agarwood (Aquilaria crassna Pierre ex Lec.) by Intentional Wounding

Abstract

Treatments applied to stimulate resinous wood accumulation that was suitable for incense were studied on 18-year-old agarwood trees, planted at the Wang Nam Khiew forestry student training station, Wang Nam Khiew district, Nakhon Ratchasima province. Four agarwood trees, with girth at breast height in the range 54.5-108.5 cm were selected. The intentional wounding was made using a drill fitted with an 8-mm bit and 17 treatments using various chemical combinations were then applied on the wounds to induce resinous wood accumulation. The aims of these experiments were to investigate the patterns and quality of the accumulated resinous wood for incense and variation due to seasons. Data were collected over intervals of 3, 6, 9 and 12 months. The results showed three patterns of resinous wood accumulation. Pattern 1 had a thin band of resinous wood that appeared as an elliptical ring between the decayed wood and normal wood surrounding the hole. Pattern 2 featured resinous wood that appeared as an elliptical ring directly next to the hole but without any decayed wood, while pattern 3 involved an absence of resinous wood but with decayed wood next to the hole. An analysis of seasonal differences showed a higher volume of resinous wood accumulated in the dry season than in the rainy season and there was less decayed wood in the dry season. Treatment with 0.1M methyl jasmonate, 0.01M methyl jasmonate, 5% Ethrel and 10% Ethrel, produced progressively higher volumes of resinous wood, respectively.

Keywords: Aquilaria crassna, incense wood, treatment techniques