Transferable Durability: Enhancing decay resistance of non-durable species with extractives from durable wood species
G T Kirker, A B Blodgett, S Lebow, C A Clausen
Extractive content and composition is a vital component of naturally durable woods; however, variability in extractives can limit their usefulness in the field. Two extractive-free, non-durable wood species were pressure treated with ethanol-toluene extractives from 8 durable wood species. Extracted Southern pine, Paulownia and unextracted Southern pine blocks were treated and challenged in soil bottle experiments with four common wood decay fungi. Weight loss from fungal degradation of the extractive-treated blocks was compared to untreated controls. Results indicated that in some cases, treatment with extracts from durable wood species decreased the percent weight loss from exposure to decay fungi. Chemical analysis of extractives from these durable and non-durable woods was performed using GC-MS and chemical components were compared. Several unique compounds were found in the more durable species compared to less durable species.
Keywords: natural durable wood, extractives, wood decay fungi, extractive transfer