The species Melia composita has come to prominence only during the last decade and has been found suitable for several applications and end uses. However, being non-durable and difficult to treat some pre-treatment is required to improve preservative uptake. Hence the effect of microwave (MW) pre-treatment was studied on the samples of Melia composita wood in order to ameliorate its retention, depth of penetration and treatability class to ensure its sustainable use for a longer duration. The samples were exposed to MW radiation of different intensities and treated with 6% solutions of CCA, ZiBOC, CCB and Borax boric acid (BBA) preservatives by a dip diffusion method for 24 hours. Results showed a significant improvement in preservative uptake after dipping for 24 hours, in comparison with the controls. The highest retention was found in the samples treated with ZiBOC preservative after their MW exposure to 840 MJ·m–3. Wood anatomical analysis after MW modification was also performed in order to assess the changes taking place within the wood microstructure. The cross-sectional analyses of the controls and the treated specimens were briefed accordingly. Results of the anatomical study exhibited a significant improvement in the effective vessel diameters of the microwave irradiated specimens due to the clearance of the occlusions blocking the vessels with respect to the control samples, which aids in increasing wood permeability and results in higher retention and penetration.

Discoloration due to the attack of sap-stain and mould fungi has been known to reduce the value and aesthetics of timber products and render them unfit for specific uses where the appearance plays a crucial role in determining its importance. The efficacy of seed oil from Azadirachta indica as a fumigant was tested against sap-stain and mould fungi in imported Tectona grandis and southern yellow pine wood at temperature 25 ± 2 °C and relative humidity 75 ± 5 %. It was observed that the neem seed oil was effective in inhibiting the growth of sap-stain and mould fungi cultured in potato-dextrose agar (PDA) medium. The inhibition in the growth of mould and sap-stain fungi on fumigated wood reveals the potential of neem seed oil as an eco friendly preservative in lieu of the existing toxic chemicals.

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