Termiticidal potency of Erythrophleum suaveolens (Guill. and Perr.) Brenan bark, Thevetia peruviana (pers.) K. Schum and Moringa oleifera Lam. root extracts as alternative to conventional synthetic preservative-chemicals

Abstract

Search for effective, ecosystem-friendly wood preservative-chemicals, as safe-alternatives to the conventional inorganic types (e.g. CCA), has currently been extensive. Bio-potency of inestimable tropical plants has assumed folkloric dimensions. Thus, the influence of cold water-soluble extracts from potrodom (Erythrophluem suaveolens) bark, moringa (Moringa oleifera) and milk bush (Thevetia peruviana) roots on the durability of pressure-treated ceiba (Ceiba pentandra) stakes (500 × 50 × 10 mm) was examined under graveyard conditions (EN 252). Their field performance was compared with their CCA-impregnated counterparts. Control stakes were untreated. T. peruviana root extract and CCA were retained most (2.08 and 2.06 × 10−4 g/mm3 respectively) then E. suaveolens and M. oleifera root extracts (1.84 and 1.74 × 10−4 g/mm3 respectively). Thevetia peruviana extract-treated stakes recorded 19.4 % hardness loss, 41.5 % mass loss and visual durability rating of 3. Similarly, E. suaveolens impregnated stakes recorded 34.6, 28.8 % and 2; M. oleifera root extract 41.2, 98.9 % and 4; CCA-treated stakes 12.7, 19.4 % and 1, and the control 100, 100 % and 4 respectively. Biocides from the plant parts (especially E. suaveolens bark) were as effective as CCA. To broaden the preservative-chemical base for the wood treatment industry, chemicals from organic sources including vegetable-based types, which act as a pool for unlimited source of innocuous biocides, need be increasingly discovered and utilized as alternatives to the efficacious but noxious inorganic types, which pose regulatory, health and environmental fretfulness. Synergy of botanic extracts with the synthetic preservative-chemicals could likewise be explored industrially.