Essential oils and plant extracts for sustainable crop protection

Abstract

In recent years, environmental issues related to the extensive use of synthetic pesticides have attracted great attention to finding sustainable methods of plant protection. Plant-derived materials, particularly essential oils (EOs) and plant extracts, are considered to be potential sources of natural compounds because of their rich chemical composition and wide range of biological activities. This review summarizes scientific evidence published between January 2015 and May 2026 on the chemical composition and biological activities of plant-derived products against phytopathogenic bacteria, fungi, insects, and weeds. Across the studies reviewed, plant-derived products showed antibacterial, antifungal, insecticidal, phytotoxic, and antioxidant effects. Essential oils showed biological activity in many of the included studies, but their activity cannot be directly compared with that of nonvolatile extracts because the available studies differ considerably in the organisms tested, experimental methods, formulations, concentrations, exposure times, and units used to report activity. Biological activities have been associated with several mechanisms, including membrane disruption, oxidative stress generation, metabolic disturbances, and interference with neuronal signalling pathways. Activity against plant pathogens has also been reported in some in vivo, greenhouse, postharvest, and field studies, although evidence from field trials is still scarce. Molecular docking studies have proposed possible interactions between individual EO constituents and molecular targets involved in bacterial virulence or insecticidal activity, but these predictions still require experimental confirmation. Despite these encouraging findings, practical use of plant-derived biopesticides is still limited by chemical variability, lack of standardized methodologies, insufficient field trials, and formulation challenges. Improved formulations, including nanotechnology-based and controlled-release systems, may help overcome some of these limitations and facilitate their use in sustainable agriculture.