Artificial inoculation of fungal isolates: The most frequently isolated fungi from infected agarwood (e.g. Chaetomium globosum and Fusarium oxysporum) were inoculated to the healthy plants by artifi cial boring on to the plants. Inoculation was made with two different fungi alone and in their combination. Observations were made at an interval of 30 days after inoculation.

This investigation showed a marked difference in the oil compositions among the treatments with regards to their quality. Valerianol (3.0%) and tetradec-anioc acid (7.1%) contents were recorded higher in the oils of naturally infected plants than in that of healthy ones (0.1% and 6.9%, respectively). Pentadecenoic acid was totally absent in the oils of healthy, whereas it was found in a greater amount (6.8%) in the oil of naturally infected plants. In contrast, dodecanoic acid (3.1%), pentadecanoic acid (6.2%), hexadecanoic acid (31.5%) and octadecanoic acid (4.1%) were found in a higher amount in the oils of healthy plants, while the oils obtained from naturally infected plants contained lower amounts of these components (2.5%, 4.8%, 20.0% and 1.0%, respectively). The oils obtained from the inoculated plants showed almost similar distribution of the components with healthy plants.