Biocidal Action of Chromolaena odorata Extract on Ganoderma lucidum and Sclerotium rolfsii

Fungi pose a serious threat to wood in service causing significant economic loss every year. In this study, Chromolaena odorata extract was investigated for its fungicide properties against Ganoderma lucidum and Sclerotium rolfsii. An ethanol-solvent system was used to remove the extract from ground leaves of C. odorata. Samples of Pinus caribaea wood from the base, middle, and top along the tree bole were soaked in five different concentrations (0%, 10%, 20%, 30%, and 40%) of C. odorata for three days, and preservative absorption and retention were determined. The treated woodblocks were exposed to actively growing cultures of wood-attacking fungi under laboratory conditions (27 °C and 65% RH) for 24 weeks. The range of weight loss of the untreated wood samples on exposure to both fungi showed that the wood is moderately resistant to fungal attack. However, the highest weight loss which was obtained in the control wood samples showed that C. odorata extract is effective in imparting some level of fungi resistance to the wood, and the optimal concentration level, based on this research is 30%.