Stinkwort (Dittrichia graveolens) organic extracts as potential biofungicides for Fusarium poae

In the present study, we tested the antifungal activity of ethanol, methanol and acetone extracts of stinkwort against pathogenic fungus grown from ecological wheat grain, molecularly identified as Fusarium poae. Its susceptibility to the stinkworth extracts was tested in vitro with agardilution method. The results of antifungal effect of the organic stinkwort extracts showed that the growth of F. poae was significantly reduced by these extracts compared to the control and that the antifungal activity is dose-dependent. The methanol extract showed stronger inhibition than the ethanol and acetone ones at all three concentrations. All organic extracts showed a similar antifungal activity against F. poae as a broad-spectrum fungicide azoxystrobin. We tested the effects of stinkwoth extracts on the germination of radish seeds. The methanol extract delayed the germination of the radish seeds during the first 24 hours, but thereafter all three organic extracts had a comparable germination rate as the control seeds. Despite the delayed germination of the radish seeds, the methanol extract did not reduce the final germination rate and at the same time reduced the fungal infection by almost 50%. These results indicate that the methanol stinkwort extract has the potential to be used as a biofungicide in organic farming.