Comparative Study of Agarwood Formation by <i>Fusarium</i> Inoculation and Physical Wounding in <i>Aquilaria malaccensis</i> Across Two Agroecological Zones of Central Nepal

Agarwood, a highly valuable fragrant wood, is obtained from the Aquilaria malaccensis tree. It is formed due to fungal infection, chemical stress, and physical damage in the plant, which takes decades to form naturally. Agarwood formation may be accelerated by using several techniques of stimulation. Therefore, this study aims to investigate the influence of Fusarium inoculation and physical wounding on agarwood formation over a short duration of time, i.e., 9 months. The comparison among fungus‐inoculated, physically wounded, and control treatments on the agarwood formation was done. The study was conducted on 30 selected trees of Aquilaria malaccensis in Gulmi and Tanahun districts of central Nepal following purposive sampling. After 9 months of inoculation and treatments, agarwood was harvested. The percentage yield of agarwood and essential oil content was analyzed and compared among the different geographical areas using ANOVA which revealed the higher agarwood formation in fungal inoculation. The regression analysis revealed that the diameter of the inoculated branch has a significant positive effect on the length of discoloration. The chemical constituents of the essential oil were identified using the GC–MS method. A total of 83 aromatic compounds were found, including agaroguran (alpha), eudesmol (gamma), caryophyllene, aristolene, cembrene, hinesol, 13‐hydroxyvalencene, and cadonol. The findings will contribute to the growth of Nepal’s agarwood production by providing insight into the influence of Fusarium on agarwood formation. Also, the chemical examination of the essential oil will aid in understanding the composition and quality of agarwood, which may be advantageous for commercial use.