The Crown rot of banana fruits is one of the major causes of produce losses during postharvest storage and market distribution and it is considered one of the most serious and frequent postharvest diseases.The main fungal agents of Crown rot of banana fruit are Fusarium semitectum e Colletotrichum musae.
The scientists at Department of Plant Pathology, National Research Centre (Giza, Egypt), have tested first in vitro and then in vivo the efficacy of different essential oils in inhibiting the growth of fungi responsible for crown rot of banana.
For the study, the essential oil of cinnamon, thyme, bitter almonds, sweet almonds were assayed. The essential oils have been applied as coating at different concentrations from 0.125% to 1% in the in vitro conditions and from 1% to 4% in the in vivo storage conditions.
In vitro tests showed that the essential oils of cinnamon and bitter almonds, applied at the lower concentration of 0.125%, significantly reduced the fungal development by 63% and 44%, respectively. The percentage of reduction of the fungal development gradually increased with increasing the concentration of the two essential oils up to reach the 100% reduction using 1% concentration. At 1% concentration, the essential oils of thyme and sweet almonds have reduced the fungal development by 71% and 63%, respectively.
In vivo tests on artificially inoculated fruits showed that the essential oils used for post-harvest treatment significantly affected the incidence and severity of crown rot.
The fungal development was reduced by 100% in bananas treated with thyme and cinnamon essential oil at 4% concentration, while it was reduced by 87% and 79% in bananas treated with sweet and bitter almond oils, respectively.
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The scientists have also evaluated the impact of postharvest treatment with essential oils on bananas organoleptic properties and they have concluded that there were not significant differences among bananas treated with cinnamon, bitter and sweet almond oils and untreated fruits (control) with respect to flavour, aroma, taste and overall acceptability.
Source: Abd-Alla MA, El-Gamal NG, El-Mougy NS, Abdel-Kader MM, Post-harvest treatments for controlling crown rot disease of Williams banana fruits (Musa acuminata L.) in Egypt, 2014, Plant Pathology & Quarantine, Vol. 4, pagg. 1-12.