Plant-derived essential oil mixture from Salvia rosmarinus, Lavandula dentata, and Cymbopogon citratus a promising biofungicide against postharvest green mold Penicillium digitatum.

Postharvest green mold, caused by Penicillium digitatum, is considered one of the most economically significant diseases affecting citrus fruit. Current management strategies for green mold rely primarily on the pre- and postharvest application of synthetic fungicides. Plant-derived essential oils (EOs) have been presented as sustainable and ecofriendly alternatives to synthetic pesticides. The objective of the present study is to evaluate the antifungal property of Salvia rosmarinus, Lavandula dentata, and Cymbopogon citratus EO and their mixture against P. digitatum. Under in vitro environment, all treatments exhibited a significant inhibitory effect on P. digitatum mycelial growth. The ternary EOs mixture exhibited significant effect compared to their individual application, showing lowest value of IC50 (0.0452 µL/mL). Moreover, the application of this mixture on infected fruits showed significant inhibitory effect compared to the control. The lesion diameter measured for untreated fruits was 64.29 mm, and 36.05 mm for fruits treated with EOs. In addition, disease incidence of P. digitatum was complete 100% in all fruits tested. Nonetheless, a significant decrease in disease severity was observed among fruits treated with EOs (56.67%). The findings of this study indicate that combining these EOs represents a promising natural strategy for controlling P. digitatum infections.