Investigating the antifungal effect of green tea extract against eight plant pathogenic fungi

In recent years, due to the indiscriminate use of chemical methods and pathogens becoming resistant to them, the use of medicinal plants to inhibit their activity has flourished. This study was conducted during 1996-94. The aim of this study is to investigate the antifungal effect of green tea extract (Camellia sinensis) using water, ethanol and methanol solvents against eight species of plant pathogenic fungi including Rhizoctonia solani, R. oryzae-sativa, Sclerotium rolfsii, Macrophomina phaseolina, Fusarium solani, Sclerotinia sclerotiorum, F. oxysporum and F. sporotrichioides were implemented. First, green tea extract was prepared. Then, using the extract mixing method, they were added in PDA culture medium at concentrations of 1000 ppm, 100 ppm and 10 ppm. Aqueous tea extract had the greatest effect on M. phaseolina fungi at concentrations of 1000 ppm and 100 ppm with 46.75% and 35.2%, respectively; S. sclerotiorum at 1000 ppm concentration by 36.11%. Methanolic extract also had the greatest effect on the above two fungi at a concentration of 1000 ppm, 45% and 35.12%, respectively. Ethanol extract showed the greatest effect on a wider range of fungi. This extract on 5 fungal isolates F. oxysporum, F. sporotrichioides, M. phaseolina, F. solani and S. sclerotiorum respectively 43.6%, 45.16%, 48.66%, 44.5% and 41.5% inhibited the growth of fungi on the surface of the Petri dish. These results showed that the effect of green tea extract is different based on the solvent, concentration and fungal isolate.