In vitro antifungal evaluation of various plant extracts against walnut anthracnose (Gnomonia leptostyla (Fr.) Ces et de Not.)

Abstract

Antifungal activity of different parts (fruit and leaf) of Cornus mas L. (Cornecea), Morus nigra L. (Moraceae) and Prunus laurocerasus L. (Rosaceae) methanol extracts has been tested against walnut anthracnose. Agar dilution method has been used in antifungal activity studies. A standard fungicide (80% Maneb; Hektas Group) was used in order to compare the herbal extracts. The highest antifungal effect was observed in the leaf extracts of C. mas and M. nigra for which mycelium growth inhibition ratios observed were 67.95% and 60.04%, respectively. Different antifungal effect ratios have been determined for other plant extracts used. Also, the effect of Gnomonia leptostyla disease on walnut yield was examined for three different types of walnut trees. According to these results, it has been concluded that walnut anthracnose disease has an effect on the yield.