Abstract:
The “Agarwood” is a resinous bio-chemical fragrant produced by certain tree species of family
Thymalaeaceae as a defense response to environmental stress. In commercial scale plantations, the
causal stress is induced by artificial fungal inoculation. The effectiveness of the inoculation process
is critically important to increase the productive harvest. The inoculum paste is made up with a high
viscous agar medium to stick to the plant tissues inside drilled holes in the tree trunk and the
branches. However, so far, no effective tool has been developed to deliver such a thick semisolid
paste into the drill holes in Agarwood trees. At present, common silicon adhesive applicators
(caulking guns) are used, which are inefficient, time-consuming, and ergonomically poor tools. To
overcome these limitations, a Pneumatic type Semi-automated Agarwood Inoculum Injector (PSAII)
was developed. A cast iron chamber of 6 L capacity was used as the pressure vessel. Standard HCFE
3/8″ non-return valve was fixed into the tank as an air inlet. The inoculum delivery out was sent
through 1mm stainless steel strainer to avoid nozzle blocking. A pressure relief valve was
incorporated to the pressure vessel and adjusted to 15 bars. The ambient air was used to compress
the inoculum inside the tank once it is filled up to 5 L loading capacity. Comparison of performance
between the new device with the existing caulking gun was done for the inoculum filling rate, labour
efficiency and the inoculum wastage. With the new device, the average filling volume of inoculum
inside the drill holes was increased up to 85.35% and reduced the inoculum wastage from 1.325mL
to 0.47mL per drill hole and both improvements were significantly different at the 5% probability
level (p<0.05). The results showed that the developed PSAII device is capable of delivering a smooth
flow of inoculum paste to the target when the impending pressure thrust range within 5 to 15 bars.
Moreover, within this pressure range, the total volume of 5L was delivered at a consistent rate. The
new device PSAII was found to be highly successful in assisting the critical process of inoculation in
the commercial level agarwood industry.
