The Influence of pH on Biodeterioration of a Tropical Timber Exposed to Mixed Cultures of Biocontrol and Wood-Rot Fungi

A laboratory investigation of the decay control potentials of Trichoderma viride and Penicillium sp. on the deterioration of obeche wood (Triplochiton scleroxylon). buffered at various pH. by wood-rot fungi ( Gloeophyllum sp. and Gloeophyllum sepiarium ), was carried out. Biomass determinations in carboxylmethyl cellulose broth at various pH showed that the biocontrol fungal strains exployed grew better as the pH approached neutral while the reverse was true for the wood-rot fungi. Deterioration of wood (buffered at various pH) simultaneously inoculated with the biocontrol and wood-rot fungi was more markedly reduced towards neutral pH than at lower pH values. Decay begun in wood initially infested with rot fungi before inoculation with biocontrol fungi was virtually halted at neutral pH. which was not the case in lower pH (2 and 3) buffered wood simultanecously inoculated with biocontrol and wood-rot fungi. A killing effect was indicated when the rot fungi failed to appear on potato–dextrose agar from interior sections of the wood blocks. Manipulation of pH may prove important in biological control of wood decay.