Plant-Based Bioherbicides: Review of Eco-Friendly Strategies for Weed Control in Organic Bean and Corn Farming

Weeds are among the primary factors limiting corn and bean productivity, accounting for up to 30% of yield losses. Although chemical herbicides remain the predominant weed control strategy, their toxicity poses significant risks to human health and the environment. In response, organic agriculture has gained prominence as a more sustainable production system, with an increasing interest in alternative weed management approaches. Plants that produce allelopathic compounds capable of inhibiting the growth of unwanted species have emerged as promising sources of natural bioherbicides. While recent reviews have primarily focused on bioherbicides derived from microorganisms, a notable gap remains regarding the production and application of bioherbicides based on plant extracts. This review addresses this gap by summarizing current knowledge on the use of plant extracts for weed control in corn and bean cultivation. It discusses extraction methods, key plant species and active compounds, target weed species, herbicidal effects, modes of action, and patented technologies. Promising plants include Cuscuta campestris, Cymbopogon citratus, Mentha spp., Eucalyptus spp., and Pinus spp., which are rich in bioactive compounds such as phenolics (i.e., flavonoids), quinones, aldehydes and ketones, lactones, terpenoids (i.e., 8-cineole), and steroids. Plant extract-based bioherbicides show promising potential as sustainable and effective alternatives for weed management in organic agriculture, contributing to reducing the synthetic chemical herbicides, avoiding more resistances of weeds resistance of control, and promoting more environmentally friendly agricultural practices.