Activity of Flavanols Extracted from Prosopis juliflora Mesquite on Growth Inhibition of Wood-Decaying Fungi and Their Synergistic Effect with Tebuconazole

Abstract

The antifungal effect of catechin and extractives from Prosopis juliflora was studied against one white rot fungus, Trametes versicolor (TV), and one brown rot fungus, Poria placenta (PP). The mentioned extractives from Prosopis julilfora were crude mesquitol and pure mesquitol. Tebuconazole was used in this study as a known fungicide against the two named fungi. Wood preservation using the current synthetic fungicides can be harmful to the environment and toxic to animals and plants. To help solve these problems, fungicides can be mixed with natural extractives to act synergistically as wood preservatives. Most of these natural extractives contain polyphenols, which are secondary metabolites, having good antioxidant properties, which may inhibit radical species involved in wood cell polymer defects. In this study, 1000 ppm and 5000 ppm of crude mesquitol, pure mesquitol and catechin had a very good growth inhibition against TV and PP. Thus, the concentrations were used to assess their synergistic response when mixed with lower inhibitory concentration of tebuconazole. The results showed that there was an additive effect in a combination of 0.1 ppm tebuconazole with 1000 ppm pure mesquitol for PP, 0.5 ppm Tebuconazole with 1000 ppm crude mesquitol and pure mesquitol for PP and 0.5 ppm tebuconazole with 1000 ppm pure mesquitol for TV. The other remaining combinations of 1000 ppm/5000 ppm of the samples with 0.1 ppm/0.5 ppm tebuconazole all had synergistic effect. This data suggests that a combination of polyphenols (catechin and extractives) with tebuconazoles can be useful sources for preparation of fungicides and wood preservatives for agricultural use and wood durability, respectively.