Abstract:
Karutha Colomban is one of the most delightful
mango varieties popular among Sri Lankan consumers. A
signifi cant postharvest loss of mango takes place every season
due to diseases including stem-end rot (SER), which is caused
by a group of endophytic fungal pathogens. In this research,
in vitro antifungal effi cacy of diff erent concentrations of
essential oils of basil, clove, and cinnamon were evaluated for
their ability to control SER causing fungal pathogens of mango
(cv. Karutha Colomban) as bio-safe alternatives to conventional
fungicides, by conducting liquid and disc volatilisation
bioassays. Major bioactive compounds of the selected essential
oils were identifi ed by gas chromatography-mass spectroscopy
(GC-MS). Basil and cinnamon bark oils (0.20 – 0.30 μL/mL)
in liquid bioassay showed high effi cacy against Lasiodiplodia
theobromae, while basil and cinnamon leaf oils (0.40 –
0.60 μL/mL) successfully inhibited Pestalotiopsis sp. Cinnamon
bark oil (0.60 μL/mL) was identifi ed as the most eff ective oil
against Phomopsis sp. According to disc volatilisation bioassay,
vapour of cinnamon oils (0.20 – 0.40 μL/mL) was the most
eff ective in controlling L. theobromae. Pestalotiopsis sp. was
effi ciently controlled by clove and cinnamon bark oil (0.20 –
0.60 μL/mL) vapour. In vapour phase, clove and cinnamon oils
(0.40 μL/mL) were the most eff ective against Phomopsis sp.
According to GC-MS characterisation, methyl chavicol was the
most abundant antifungal component in basil oil while it was
(E)-cinnamaldehyde in cinnamon bark oil. Moreover, eugenol
displayed the highest abundance in clove and cinnamon leaf
oils. Based on in vitro studies, it could be concluded that
cinnamon bark oil in liquid and vapour phases demonstrated
a higher antifungal effi cacy among the tested essential oils in
controlling fungal pathogens causing SER of mango.
