Laboratory determination of the natural decay resistance of some lesser-utilized timbers from Tanzania against wood decay fungi
IRG/WP 04-10517
P R Gillah, R C Ishengoma, E Julias, S A Amartey, D H Kitojo
Four lesser known/utilized timber species (sap and heartwoods) from Tanzania, namely Albizia lebbeck, Zanthoxylum gilletii, Faurea saligna and Parinari curatellifolia were exposed to the brown rot fungi (Gloeophyllum trabeum and Coniophora puteana) and the white rot fungus (Coriolus versicolor) to determine their natural decay resistance according to the EN 113 standard procedure. The timbers were also ranked into natural durability classes according to EN 350-1.
Albizia lebbeck, Faurea saligna and Parinari curatellifolia timber species (heartwood) were found to be very resistant while Zanthoxylum gilletii was heavily decayed by all the fungi. The durability ratings of the timbers were; Albizia lebbeck (1), Faurea saligna (1), Parinari curatellifolia (1) and Zanthoxylum gillettii (5).
It is suggested that the durable timbers, Albizia lebbeck, Faurea saligna and Parinari curatellifolia should be promoted as alternatives to the well known durable timber species in Tanzania such as Tectona grandis, Afzelia quanzensis, Blachylaena hutchinsii and Pterocarpus angolensis which are currently being over-exploited.