Lavender oil as eco-friendly alternative to protect wood against termites without negative effect on wood properties

Kristýna Šimůnková,Miloš Pánek,Štěpán Hýsek,Jan Šobotník,Tereza Lišková,Ladislav Reinprecht

doi:10.1038/s41598-022-05959-5

Kristýna Šimůnková, Miloš Pánek + Show 4 more

Open Access

https://doi.org/10.1038/s41598-022-05959-5

Copy DOI

Abstract

Timber suffers from various biological damages. Recent efforts aim on nature-friendly sustainable technologies of wood protection to replace classical synthetic agents having usually negative impact on many non-target organisms including man. This research investigated the biocidal effectiveness of lavender oil (LO) in protecting the Norway spruce (Picea abies) wood against the termites Reticulitermes flavipes and the brown-rot fungus Rhodonia placenta. Following, selected physical characteristics of spruce wood treated with LO were evaluated: colour changes, roughness, surface wetting with water and surface free energy (SFE). Experiments showed that LO increased the resistance of spruce wood to termites nearly to the level of its treatment with commercial biocide based on trivalent boron and quaternary ammonium salt. The additional hydrophobic treatment of wood ensured its full termite-resistance even after artificial weathering in Xenotest and leaching in water according to EN 84, respectively. It shows a high potential of LO to protect wood against termites. Adversely, the effectiveness of 5% LO against rot was not sufficient. The colour of the oil-treated wood was preserved, its roughness increased slightly, and wetting and SFE led to a positive change, improving the adhesion of potentially applied coatings or adhesives for exterior exposures.

Highlights

Results clearly show that lavender essential oils (EOs) is an effective insecticide (Figs. 1 and 2), to other EOs protecting the wood against various pests including termites[74–77]
More other essential oils were effective against termites, limitations for wood protection in practice are that only nutrient medium was used or no information about treatment method was d isclosed[46]
Our results show that while strongly diluted lavender EO is extremely effective against wood-feeding insects “such as termites”, only much higher concentrations might be effective for wood protection against wood-decaying fungi[52,85]

Summary

Introduction

This research investigated the biocidal effectiveness of lavender oil (LO) in protecting the Norway spruce (Picea abies) wood against the termites Reticulitermes flavipes and the brown-rot fungus Rhodonia placenta. The additional hydrophobic treatment of wood ensured its full termite-resistance even after artificial weathering in Xenotest and leaching in water according to EN 84, respectively. It shows a high potential of LO to protect wood against termites. Of the nature and origin of the biocide, additional hydrophobic coating of treated wood is usually used to improve the long-term stability[13–16] Another promising alternative is targeted modification of the wood structure—thermally modified wood, acetylated wood, etc.[17]. The potential of LO in wood protection was not much studied so far (but s ee[50,52,65])

Methods

Results

Conclusion