Dahoma (Piptadeniastrum africanum) is a durable but a lesser utilised tropical hardwood species from Ghana that has the potential of being used as an alternative to Iroko (Milicia excelsa) for many end uses. However, the timber gives off a strong odour especially when wet and during processing. The high durability and the strong odour of the timber could be due to the presence of extractives in the wood. This research is to determine the role played by the extractives in conferring natural durability to the timber. The extractives in the timber were sequentially removed using various solvents with low polarity to high polarity: petroleum spirit, diethyl ether, acetone, methanol and water. The total extractives removed from the wood specimens and wood meal were between 7.14% and 9.61% respectively. The extracted and un-extracted wood samples were exposed to white-rot fungi (Trametes versicolor and Phanerochaete chrysosporium), and brown-rot fungi (Coniophora puteana and Gloeophyllum trabeum) over twelve weeks according to BS EN113. The results obtained showed that the amounts of extractives removed by petroleum spirit, diethyl ether and acetone, which are low and intermediate polarity solvents were very small, compared to those removed by methanol and water, which are high polarity solvents. The methanol and water-soluble extractives accounted for 42% and 53% respectively of the total amount of extractives removed. The weight losses of the petroleum spirit, diethyl ether and acetone extracted samples after exposure to both the white- and brown-rot fungi increased slightly with each extraction. However, significantly high weight losses were obtained when the methanol-extracted samples were exposed to the white-rot fungi but not for the brown-rot fungi. This suggests that the extractives removed by methanol play an important role in the decay resistance of the wood to white-rot fungi, but not to the brown-rot fungi.

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