Pathogenicity of Ganoderma boninense tested by inoculation of oil palm seedlings

The pathogenicity of Ganoderma boninense isolated from oil palm was tested using wood blocks from a rubber tree as the substrate for the inoculum. Seedlings with roots placed in close contact with the inoculum blocks gave 100% infection. There was a progressive desiccation of leaves from the oldest to the youngest. Sporophores emerged as a white mass of mycelial tissue which rapidly became button‐like. This was followed by the development of the stipe. Bracket‐shaped sporophores formed within 12–16 weeks after inoculation. Longitudinal sections of affected seedlings revealed bole and stem decay. Hyphae were detected in the cortex, endodermis, pericycle and vascular tissues of infected roots. Gummosis and the production of tyloses in xylem vessels were common.