Background: Basal rot of onion (
Allium cepa
L.) caused by
Fusarium oxysporum
f. sp.
cepae is a common soil-borne disease that causes significant
yield losses. Generally, synthetic fungicides are used to combat the menace which causes environmental pollution. The present study was carried out
to assess the antifungal activity of
Withania somnifera
(L.), Dunal, a Solanaceous medicinal plant, against the pathogen of this disease.
Materials and Methods: Different concentrations (from 0.5 to 4%) of methanolic extract of root stem and fruit of the test plant species were
prepared and their bioactivity was assessed against the target fungal pathogen. Methanolic extract of root was further fractionated with
n-hexane,
chloroform, ethyl acetate and
n-butanol. A range of concentrations of these extracts viz. 200, 100… 3.125 mg mL
-1 were prepared and assessed for
their antifungal activities.
Results: Methanolic root extract exhibited the best antifungal activity, causing up to 93% decrease in biomass of the fungal pathogen.
n-hexane,
chloroform and ethyl acetate fractions of methanolic root extract exhibited pronounced antifungal activity resulting in 46–79%, 40–73% and 35–76%
reduction in fungal biomass respectively.
Conclusion: The present study concludes that root extract of W. somnifera possesses potent antifungal constituents which can be used for the control
of
F. oxysporum f. sp.
cepae.
