Antifungal Activity of Various Medicinal Plants against Late Blight of Potato from Ethiopia

Aims: Emerging losses caused by late blight of potatoes need new approaches to control Phytophthora infestans. Searching for novel molecules with antifungal activity, twelve medicinal plants from Ethiopia were investigated against this pathogen.

Methodology: To accomplish this task, growth inhibitory effect of aqueous, ethanolous, and methanolous extracts of various medicinal plants were tested in vitro by applying agar well diffusion technique.

Results: All plant extracts except Eucalyptus globules and Hagenia abyssinica showed promising antifungal activity against the P. infestans mycelial growth. Datura stramonium, Rhamnus prinoides and Moringa stenopetala exhibited highest activity against P. infestans. Direct germination of zoosporangia was also significantly inhibited by all extracts of medicinal plants except E. globules and H. abyssinica. Methanolous extract of Nicotinia tabacum did not inhibited either mycelium growth or sporulation of the fungus.

Conclusions: Various products of proposed medicinal plants deserved to be reliable sources as antifungal agents and might play significant role for future practical applications in a socially and ecologically healthy management of late blight of potatoes. Further work in this direction can give insight into novel antifungal targets and molecules for prevention of P. infestans infection, especially against late blight of potato and tomato.