Potential of essential oils as natural herbicides: a comprehensive review of current developments

Weeds compete with crops, reducing their productivity, and continuous use of inorganic herbicides disrupts environmental balance. In light of current environmental concerns, organic products have gained popularity, with essential oils emerging as potential natural herbicides. A systematic review of 100 studies from 2000 to 2024 highlights increasing interest in weed control through essential oils, particularly in Europe. Eighteen studies included in meta-analysis revealed that essential oil treatments significantly reduced weed shoot and root length and weight, achieving 45–92% growth control. Key terpenes such as 1,8-Cineole, ρ-Cymene, and α-Pinene were identified as the primary phytotoxic compounds. Modifying formulations through encapsulation and emulsification enhanced the stability, efficacy, and retention time of essential oils. The meta-analysis indicated moderate to high heterogeneity (I² values of 0.58 and 0.98), attributed to factors like active compounds, weed species, climatic conditions, and assay types. The review concludes that further in-depth studies are necessary to develop sustainable, eco-friendly herbicides from essential oils.