Antifungal activity of some botanical extracts on Fusarium oxysporum

Abstract

The present paper describes the antifungal activity of some plant extracts on the development of Fusarium oxysporum f.sp. lycopersici. The best extracts were selected to be tested as a phytofungicide to control crop diseases, with the ultimate goal of developing a green alternative to synthetic fungicides. Using the conidia germination assay, of the 24 plant extracts tested, 15 reduced conidia germination and 6 completely inhibited germination. Extracts of Rivina humulis, Brassica carinata, Brunfelsia calyicina, Salvia guaranitica and Punica granatum showed good antifungal activity. The relationship between total phenolic content (TPC) in each plant extract tested and the percentage of mycelial growth inhibition showed a significant correlation (R2= 0.69), while no correlation was found between total flavonoid content (TFC) and percentage mycelial growth inhibition. Among all extracts tested, Punica granatum and Salvia guaranitica showed the best inhibitory effect against Fusarium oxysporum f.sp. lycopersici. Our results indicate that plant extracts with a good antifungal activity generally had a high level of total polyphenolic content and titratable acidity, and low values of pH.