Effect of myrtle essential oil, chitosan and thiabendazole fungicide on citrus green mold

Green mold (Penicillium digitatum) is one of the most important post-harvest pathogens of citrus fruits. Tens of thousands of citrus fruits are often destroyed by green mold in Iran every year. The use of chemical toxins to control the disease, in addition to negative environmental effects, leads to the selection of fungal-resistant populations and also endangers consumer health, so non-chemical control of the pathogen has become an important goal of researchers in recent years.

The essential oil components of myrtle (Myrtus communis L.) were extracted with a Clevenger apparatus and their compounds were identified with a gas chromatography apparatus with a mass spectrometer. The inhibitory effect of myrtle essential oil and the fungicides chitosan and thiabendazole on spore germination and colony growth was investigated by mixing with PDA and PDB under laboratory conditions and by impregnating the fruit surface during storage.

Thirteen compounds were identified in myrtle essential oil, which was quantitatively the highest compound 1-8 cineole. Myrtle essential oil at a concentration of 1700 ppm and chitosan at a concentration of 500 ppm inhibited 100% of fungal colony growth, as did the fungicide thiabendazole.

It is possible to use myrtle essential oil or chitosan as an alternative to the fungicide thiabendazole to control citrus green mold.