Antifungal Activity of Essential Oils of Ocimum gratissimum and Cymbopogon citratus Leaves Against Post–harvest Fruit Rot of Citrus sinensis

Kanife, Uche; Ebabhi, Abosede Margaret; Ofodile, Lauretta Nwanneka; Onyeaghasiri, Faustina Uloma; Obayiuwana, Amarachukwu Chigozie; Adekunle, Adedotun Adeyinka; Ayodeji, Adekunle Ayo

doi:10.21608/ejp.2025.370122.1136

Antifungal Activity of Essential Oils of Ocimum gratissimum and Cymbopogon citratus Leaves Against Post–harvest Fruit Rot of Citrus sinensis

Document Type : Original Article

Authors

¹ Department of Biological Sciences, Yaba College of Technology, Yaba, Lagos , Nigeria

² Department of Education, Biology Unit,Distance Learning Institute, University of Lagos, Lagos, Nigeria

³ Department of Biological Sciences, Yaba College of Technology, Yaba, Lagos, Nigeria

⁴ Department of Microbiology, University of Benin, Benin City, Nigeria

⁵ Department of Biological Science,Augustine University, Ilara, Epe, Lagos,Nigeria

⁶ Department of Botany, University of Lagos, Akoka, Lagos, Nigeria

⁷ Department of Statistics,Yaba College of Technology, Yaba, Lagos, Nigeria

10.21608/ejp.2025.370122.1136

Abstract

Citrus sinensis fruit is susceptible to post-harvest fungal rots. Eight fungal isolates were isolated from diseased Citrus sinensis fruits ,they were identified via Sanger sequencing with Lasiodiplodia theobromae and Aspergillus flavus showing high pathogenicity (≥75%), hence most virulent causing post-harvest rot in Citrus sinensis. This study investigated the effectiveness of essential oils from Ocimum gratissimum and Cymbopogon citratus leaves against Lasiodiplodia theobromae and Aspergillus flavus. In vitro assays showed a dose-dependent antifungal effect. Cymbopogon citratus at 1.00 µg/ml exhibited the highest inhibition zones against Lasiodiplodia theobromae (86.10±0.11mm) and Aspergillus flavus (62.11±0.04mm), while Ocimum gratissimum caused inhibition zones of 72.18±1.90mm and 24.35±0.56mm, respectively. Both oils outperformed mancozeb at 2.00 µg/ml (25.33±0.58mm). The antifungal activity was linked to key compounds such as eugenol (7.73%), linalool(12.34%), nerolidiol 2 (5.28%) and beta.-isabolene(5.11%), cyclohexane (4.99%), caryophyllene (3.31%) in Ocimum gratissimum, and geranial(39.05%), neral(28.20%), geraniol(6.33%), limonene(5.08%), geranylacetate(2.46%), isogeranial(1.49%), limonene(0.83%) in Cymbopogon citratus. Gas chromatography-mass spectrometry (GC-MS) analysis characterized the essential oils, revealing bioactive compounds. The findings suggest that these plant-derived essential oils can serve as effective bio-fungicides for controlling post-harvest rots in Citrus sinensis, promoting sustainable fruit production.

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