Lippia graveolens and Carya illinoensis Organic Extracts and there in vitro Effect Against Rhizoctonia Solani Kuhn

Problem statement: Plant extracts with polyphenolic compounds obtained with different solvents have been evaluated against plant pathogens. However, most of these extract have been obtained using solvents no allowed under an organic production context. Approach: In the present research was to evaluate the inhibitory effect of polyphenolic extracts from L. graveolens and C. illinoensis, obtained with alternative organic solvents (lanolin and cocoa butter), water and ethanol against R. solani in order to determine the Inhibitory Concentration (IC₅₀) of each extract. Results: The results showed that extracts of both L. graveolens and C. illinoensis obtained with lanolin and ethanol (200 and 3000 ppm of total tannins, respectively) inhibited at 100% growth of R. solani. The IC50 for each extract was highly variable, low IC50 values were obtained with L. graveolens (4.50×10¹) and C. illinoensis (4.33×10²) extract using lanolin and ethanol respectively. Tannins extraction was strongly dependent on plant species and in the solvent used. Conclusion: The alternative organic solvents lanolin and cocoa butter allowed the recovery of polyphenols compounds with antifungal activity against R. solani.