Articles » Effect of some essential oils on mycelial growth of Penicillium digitatum Sacc.
Foeniculum vulgare (fennel), Thymus vulgaris (thyme),
Eugenia caryophyllata (Clove) and Salvia officinalis (sage)
was tested in vitro against Penicillium digitatum Sacc.
Direct contact and vapour phase were used to test the
antifungal activity of these essential oils against P. digit
atum that is responsible for green mould rot of citrus fruits.
The vapour phase and direct contact of clove and thyme
essential oils exhibited the strongest toxicity and totally
inhibited the mycelial growth of the test fungus. Thyme
and clove essential oils completely inhibited P. digitatum
growth either when added into the medium 600 ll l-1 or
by their volatiles with 24 ll per 8 cm diameter Petri dish.
In in vitro mycelial growth assay showed fungistatic and
fungicidal activity by clove and thyme essential oils. Sage
and fennel oils did not show any inhibitory activity on this
fungus. Scanning electron microscopy (SEM) was done to
study the mode of action of clove oil in P. digitatum and it
was observed that treatment with the oil leads to large
alterations in hyphal morphology.