P. cinnamomi was recently isolated from necrotic root tissues of 2-year old die-back cloves; this being the first record of the fungus on clove plants. Laboratory studies indicated that chlamydospores were freely produced in artificial culture media although sporangia were only sparingly produced in LBA and OMA at 25°C. Sporangial production could be easily induced, however, when culture discs from young colonies were placed in either soil extract, petri solution or distilled water. The ability of the fungus to form oospores with an A₁ isolate of P. palmivora from black-pepper indicated that the present isolate belonged to the A₂ compatibility type. Results obtained from a series of inoculation studies showed high susceptibility of unripe cocoa and rubber pods as well as avocado seedlings and fruits to the fungus. The importance of these findings in relation to cocoa, rubber and avocado cultivation in Malaysia is briefly discussed.

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