Cell-Free Fungal Mycoherbicides for Sustainable Weed Management

Abstract

Weed infestations remain one of the major constraints to global agricultural productivity, causing significant yield losses and increasing dependence on synthetic herbicides. The rapid evolution of herbicide-resistant weed populations, environmental concerns associated with chemical herbicides, and increasing demand for sustainable crop production systems have intensified the search for alternative weed management strategies. Mycoherbicides, traditionally based on living fungal propagules, have emerged as promising biological weed control agents. However, limitations associated with living fungal formulations, including environmental sensitivity, short shelf life, inconsistent field performance, and regulatory challenges, have restricted their widespread commercialization.
Cell-free fungal broth-based mycoherbicides represent a new generation of bioherbicides that exploit fungal-derived bioactive compounds without requiring viable fungal propagules. These preparations offer several advantages, including improved formulation stability, enhanced biosafety, simplified regulatory requirements, easier standardization, and compatibility with modern formulation technologies.
This review critically examines the current status of cell-free fungal broth-based mycoherbicides, covering fungal strain selection, fermentation processes, metabolite production, characterization methodologies, formulation technologies, mechanisms of herbicidal action, field application strategies, commercialization prospects, and regulatory considerations. Future opportunities involving synthetic biology, metabolic engineering, artificial intelligence-assisted metabolite discovery, nanoformulations, and precision application systems are also discussed.
The integration of cell-free fungal bioherbicides into integrated weed management programs may provide environmentally sustainable solutions for reducing reliance on synthetic herbicides while supporting long-term agricultural productivity.

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