Efficacy of Lemon Myrtle Essential Oil as a Bio-Fungicide in Inhibiting Citrus Green Mould

• Published in: Plants (Basel) Vol. 12; no. 21; p. 3742
• Main Authors: Rahman, Mohammad M, Wills, Ronald B. H, Bowyer, Michael C, Vuong, Van Q, Golding, John B, Kirkman, Timothy, Pristijono, Penta
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.10.2023
• Subjects: Antibiotics; Chemical properties; Citral; Citrus; citrus fruit; Citrus fruits; Control; Dipping; Diseases and pests; Essences and essential oils; essential oil; Essential oils; Fruit; Fruit industry; Fruits; Fungal diseases of plants; Fungi; Fungicides; Gas chromatography; Green mold; Laboratories; lemon myrtle; Mass spectrometry; Mass spectroscopy; Mold; Myrtle; Oils & fats; Organic chemicals; Penicillium digitatum; Pesticides; Resveratrol; rind injury; Sensory properties; Temperature; Testing; Australia; United Kingdom; United States > US; Germany
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants12213742

The effectiveness of lemon myrtle (LM) (Backhousia citriodora) essential oil (EO) was investigated to combat Penicillium digitatum by in vitro agar diffusion and vapour assay and in artificially infected oranges. The main constituent of LM EO was revealed as citral when analysed in gas chromatography–mass spectrometry. Pure citral was also included in the experiment for comparison. The in vitro fungal growth was significantly inhibited by LM EO at 1, 2, 3, 4 and 5 μL per disc while complete growth inhibition by both the pure citral and LM EO occurred at 4 and 5 μL per disc. Inoculated fruits treated by dipping in 1000 μL L−1 LM EO solutions for 5, 10, 15, 30 and 120 s showed significantly lower fungal wounds compared to control. While longer dipping times led to some rind injuries, fruits with a 5 and 10 s dip were found free from any injury. The evaluation after dipping and storage confirmed that the fruits maintained the sensory attributes and were not compromised by the incorporation of the essential oil. The results of this study indicate that LM EO can be a promising alternative to synthetic fungicides for preserving the quality of citrus fruits during storage.