earticle

영어

The increasing concern by the public regarding the environmental impacts associated with the utilization of synthetic preservatives continues to propel the search for environmental benign alternatives. Therefore, this study investigated the efficacy of Azadirachta indica and Kigelia africana leaves extracts in the protection of Triplochiton scleroxylon wood against fungal decay. The dried leaves of both plants were pulverized and six extracts were prepared: Aqueous Kigelia extract (KW), Ethanolic Kigelia extract (KA), Aqueous Azadirachta extract (AW), Ethanolic Azadirachta extract (AA), 1:1 KW to AW (KAW), 1:1 KA to AA (KAA) using distilled water and 100% ethanol as the diluent. T. scleroxylon blocks of dimension 2 cm×2 cm×6 cm were oven-dried and soaked in each extract for 24 hrs, with water (CW) and ethanol (CA) serving as control. Parameters observed include extract yield, colour changes, extract absorption and retention. The treated woods were inoculated with the fungi Pleurotus ostreatus (white rot) and Aspergillus niger (brown rot) for 12 weeks after which their weight loss was determined. Data analysis was conducted using ANOVA at 5% probability level. The extract yield ranged between 1.20%-8.73%. Wood samples treated with the AW extract had the highest absorption (31.26 kg/m3), while extract retention was highest in both KA and AA (3.7 kg/m3). Colour changes, particularly in the samples treated with the aqueous extracts, was noticeable. Highest weight loss was observed in both CA (43.81% and 46.45%) and CW (50.23% and 51.11%), while KW (9.33% and 12.01%) treated samples had the lowest weight loss after exposure to P. ostreatus and A. niger, respectively. Synergistic effect of both extracts was significant on the absorption, retention and weight loss of the wood samples exposed to fungi. It was concluded that KW extract is the most effective in protecting the wood against fungal decay.