Chilean Aloysia Essential Oils: A Medicinal Plant Resource for Postharvest Disease Control

Postharvest fungal rot causes significant economic losses in the agroindustry. Current control methods involving the use of synthetic fungicides are becoming increasingly ineffective and pose environmental risks. This necessitates exploring sustainable alternatives, such as essential oils derived from medicinal plants, to achieve safer and effective disease control. This research examined the chemical composition and efficacy of essential oils from Aloysia citriodora, Aloysia polystachya and their compounds against the postharvest rot fungi Monilinia fructicola, Monilinia laxa, and Botrytis cinerea. The main compounds of essential oils were analyzed by GC/MS and revealed differences in their composition. A. citriodora is characterized by the presence of spathulenol and caryophyllene oxide. In contrast, A. polystachya is characterized by the predominance of carvone. The results show that the essential oil of A. citriodora and the compound farnesol are able to inhibit the three pathogens. Notably, against M. fructicola, the EC50 values were 61.89 μg/mL and 72.18 μg/mL, respectively. Against B. cinerea, the EC50 values were 85.34 μg/mL and 47.6 μg/mL. Molecular docking also showed that farnesol has affinity for the enzyme succinate dehydrogenase suggesting a possible mechanism of action. This compound and A. citriodora essential oil show potential in the control of phytopathogens.