Application of extracts from the poisonous plant, Nerium Oleander L., as a wood preservative

The antifungal properties of poisonous plant extracts from oleanders ( Nerium oleander L.) were determined when used as a wood preservative. The extract was prepared from oleanders leaves and flowers in 96% ethyl alcohol. The wood blocks of Turkish oriental beech (Fagus orientalis L.) and Scots pine ( Pinus sylvestris L.) were impregnated with the extracts. The abilities of the extract to suppress attack by Postia placenta (Fr.)(brown rot) and Trametes versicolor (L: Fr.) Quel. (a white-rot) was investigated. Treated blocks were exposed to P. placenta and T. versicolor attacks for 12 weeks by following the soil-block method. While untreated wood specimens have weight loss ranging between 27.37 and 30.66% for P. placenta and 8.64 and 24.06% for T. versicolor, the wood treated with the extracts is of weight loss between 5.54 and 10.98% for P. placenta, and between 5.02 and 28.25% for T. versicolor. The lowest weight loss was found to be for beech wood (5.02%) impregnated with the extract of oleander at a concentration level of 0.25% against T. versicolor. While the highest weight loss was also on the beech wood (28.25%) treated with the same extract at the level of 0.50% concentration against T. versicolor. In conclusion, the extracts could be used as effective wood preservative.