Design, Development and Performance Evaluation of Pneumatic Type Agarwood Inoculum Injector (PAII)

Agarwood, a fragrant resin, is produced by certain tree species in the Thymalaeaceae family as a defense mechanism against stress. In commercial plantations, artificial inoculation of the fungal mix is used to induce the said stress, which is crucial for a fruitful harvest. The paste, containing viscous agar to be applied into drilled holes in the tree trunks and branches. Yet, an efficient tool to deliver this paste is lacking. Currently, inadequate industrial caulking guns are being used, proving time-consuming and ergonomically subpar design. To overcome these limitations, a Pneumatic type Agarwood Inoculum Injector was developed. A 6L capacity cast iron chamber was used as the core pneumatic body of the injector. An HCFE 3/8″ non-return valve served as the air inlet. The delivered inoculum passed through a 1mm stainless steel strainer to prevent nozzle blockage. A pressure safety valve, set at 15 bars, released excess pressure. Inoculum compression relied on ambient air, filling up to 5L. A comparison of performance between the new device with the existing caulking gun was done for the inoculum filling rate, time taken to complete a single inoculation point, and the prevented volume of 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 concluded that the developed device is capable of delivering a smooth flow of inoculum paste to the target when the impending pressure thrust range is within 5 to 15 bars. Moreover, within this pressure range, the total volume of 5L was delivered at a fairly consistent rate. The invented new device was found to be highly successful in assisting the critical process of inoculation in the commercial-level agarwood industry.