Pro Ligno (Dec 2016)
Weight Loss and Compressive Strength of Castor Oil-Treated Pinus Caribaea (Morelet) Wood Exposed to Fungi
Abstract
The need for environmental sustainability calls for a radical change from the use of synthetic wood preservatives which persist in the environment even after wood has been taken out of service. There has therefore been a growing interest in the development of efficacious biocides from plants, prompting the exploration of castor seed oil as a potential wood antifungal in this study due to its reported antimicrobial properties. Thus, this study aimed at evaluating the resistance of castor oil treated P. caribaea wood against two strains of wood basidiomycetes. Five trees of Pinus caribaea were harvested at Shasha Forest Reserve, Osun State. Wood samples were obtained from the top, middle and base of the trees. The samples were conditioned and treated with four formulated fungicides prepared from mechanically extracted oil of castor seeds. The treated and control samples were inoculated with Sclerotium rolfsii (Brown rot) and Ganoderma lucidum (White rot) for 24 weeks. Parameters such as oil yield, preservative absorption, weight loss and compressive strength of the treated wood samples were determined. ANOVA was used in analyzing the data generated. Results show that the oil yield of the seed of the plant is 41.75%. The preservative absorption of the wood ranged between 114.85 - 277.12 (Kgm-3 ), weight loss (1.36 - 15.85%) and MCS// (33.05 - 48.35N/mm2 ). Sampling height and preservative concentration significantly influenced weight loss of the wood (p<0.05). The 30% preservative concentration performed best, having the least weight loss (1.71% and 1.61%) and highest MCS// (47.06N/mm2 and 44.65N/mm2 ) after exposure to S. rolfsii and G. lucidum, respectively. The brown rot (4.12%) was more virulent than the white rot (3.66%) on the basis of wood weight loss, however, the MCS// results indicated otherwise. It is concluded that castor seed oil is effective in protecting wood against white and brown rot fungi.
