Antifungal activities of two essential oils used in the treatment of three commercial woods deteriorated by five common mold fungi

• Three commercial woods inoculated with five molds and treated with two essential oils (EOs) were investigated.
• EOs were applied to Pinus sylvestris, Pinus rigida and Fagus sylvatica woods by vapors method.
• α-terpineol, borneol, fenchyl alcohol, and α-pinene were the major components P. rigida wood EO.
• Eucalyptol, α-pinene, γ-terpinene, and terpinen-4-ol in Eucalyptus camaldulensis leaves EO.
• P. rigida wood oil vapor provided significant reduction of mold growth on the wood surfaces than E. camaldulensis leaves EO.

In the past ten years natural extracts have been used as important potential applications to prevent mold growth on in-service wood. The growth of fungal hyphae of five common mold fungi (Alternaria alternata, Fusarium subglutinans, Chaetomium globosum, Aspergillus niger, and Trichoderma viride) on wood surface of Pinus sylvestris, Pinus rigida and Fagus sylvatica treated with the essential oil (EO) of P. rigida (wood) and Eucalyptus camaldulensis (leaves) was visually estimated. EOs were applied by vapor method and the mold growth inhibition was measured. The chemical constituents of the EOs was analyzed by GC/MS, which referred to the presence of α-terpineol (34.49%), borneol (17.57%), and fenchyl alcohol (14.20%) as the major components in P. rigida wood oil, and eucalyptol (60.32%), α-pinene (13.65%), and γ-terpinene (8.77%) in E. camaldulensis leaves. Complete inhibition against the growth of A. alternata, F. subglutinans, C. globosum, and A. niger except of T. viride by applying P. rigida wood EO at 5000 ppm and complete growth with all the studied fungi except of C. globosum at 156.25 ppm was found. Good inhibitions against C. globosum at 5000 ppm and 156.25 ppm and no inhibition against A. niger and T. viride and little inhibition against F. subglutinans at high concentration was found by the application of EO from E. camaldulensis leaves. These findings support the potential use of the EOs for wood protection against mold infestation for surface-treatment or fumigation of wood products.