Assessment of bio-preservative potential of <i>Gmelina arborea</i> roxb. Seed-oil on laminated bamboo against termite attack

Abstract

The efficacy of Gmelina arborea seed-oil as preservative on laminated bamboo against termite attack was investigated. Gmelina arborea fruits and ten matured Bambusa vulgaris of over 4 years were sourced from Oyo State, Nigeria. Oil was chemically extracted from the G. arborea seeds using n’ hexane and ethanol solvents and thereafter mixed with kerosene (at 50%) using volume-to-volume method to increase its quantity. The phytochemical screening of the seed of Gmelina arborea revealed the presence of tannins, alkaloids, flavonoids, saponins and phenols at different quantity. Strips from the base, middle and top of the harvested bamboo culms were soaked in the hexane and ethanol extracted G. arborea seedoil while, the untreated samples served as the control and thereafter used to produce boards. The production of laminated bamboo board was carried out in Bamboo and Rattan Workshop of Forest Products Development and Utilization Department, Forestry Research Institute of Nigeria, Ibadan, Nigeria. Durability test was carried out and data were analysed using descriptive statistics and ANOVA at P<0.05. From the results, the weight loss from termite attack of the laminated boards ranged from 7.93 to 27.75% with increase from top to base resulting in decrease in weight loss of the boards produced. Boards preserved with G. arborea seed-oil ethanol extract were more resistant to termite attack (12.29%) compared to those preserved with the G. arborea seed-oil n’ hexane extract (13.59%). Based on the result obtained, G. arborea seed-oil extracts have the potential of being an effective wood preservative.

Keywords: Bamboo, G. arborea seed-oil, chemical extraction, phytochemical, weight loss