Agarwood-inducing microbial inoculant in powder formula.

The high demand of natural impregnated heartwood resin, agarwood, has led to the scarcity of naturally-grown agarwood-producing trees. Developing effective microbially-induced agarwood formation in cultivated agarwood-producing trees is pivotal in meeting the demand. Previously developed inoculation method to induce agarwood formation uses liquid medium for agarwood-inducing fungi Fusarium solani. While this inoculant has successfully induced agarwood formation, its liquid form became a challenge when transported in a large amount. Solidification of the inoculant while maintaining its effectiveness was developed to ease the distribution process. This study observed and compared the agarwood formation that was induced by the liquid, concentrated liquid, and partly lyophilized F. solani inoculants. All inoculants were stored for one, two, and three month(s) prior to inoculation. The concentrated liquid and lyophilized or powder inoculants were mixed with sterile water to reach their original concentration prior to inoculation. Agarwood formation was observed in 5-year-old Gyrinops sp. inoculated trees with diameter of 15 cm at breast high with five replications. For inoculants that have been stored for one month, the original liquid inoculant induced agarwood formation area with 21.95±6.03 cm², 34.13±12.67 cm², and 37.15±7.60 cm² after the first, second, and third monthly observations, respectively. The partly lyophilized inoculant performed comparably to the original liquid inoculant with 18.86±6.49 cm², 24.26±12.67 cm², and 33.75±16.09 cm² one, two, and three months after inoculation, respectively. The concentrated liquid inoculant generated slightly larger agarwood formation than the original liquid inoculant with 24.73±6.92 cm², 38.01±15.51 cm², and 43.95±11.65 cm² after the first, second, and third monthly observations, respectively. Inoculants that have been stored for two months displayed similar pattern, whereas those that were stored for three months performed noticeably poorer than the former. These results indicated that concentrated and the partly lyophilized inoculants still produce comparable agarwood formation while remarkably reducing their liquid volume during transfer, making them promising and favourable agarwood microbial inoculants. [ABSTRACT FROM AUTHOR]