Biological Control of Weeds Using Fungal Pathogens

Weed infestations pose a critical threat to agriculture and native ecosystems, driving yield losses, biodiversity decline and increased production costs. Conventional synthetic herbicides have dominated weed management for decades, but their overuse has precipitated widespread resistance, non-target effects and environmental contamination. In response, biological control using fungal pathogens—often termed mycoherbicides—has emerged as a sustainable alternative. Fungal agents can infect or intoxicate specific weed species, exploiting mechanisms such as tissue necrosis, disruption of photosynthesis and inhibition of germination enzymes. Advances in mass-production technologies, including submerged and solid-state fermentation, now enable scalable manufacture of spores, mycelial extracts and purified phytotoxins. Successful field applications have demonstrated selective suppression of problematic weeds with minimal impact on crops and soil biota. Integration of fungal biocontrol agents into integrated weed management can reduce chemical inputs, slow resistance development and contribute to circular-economy strategies by valorising agro-industrial by-products as culture substrates. Despite promising outcomes, challenges remain in formulating stable preparations, ensuring consistent efficacy under variable environmental conditions and navigating regulatory frameworks.

Research from Nature Portfolio

Recent studies have demonstrated the potent bioherbicidal activity of secondary metabolites produced by Diaporthe species. Extracts obtained via sequential solvent partitioning exhibited more than 90 % inhibition of Amaranthus tricolor germination and seedling growth, associated with reduced α-amylase activity and osmotic imbalance during imbibition. Cytogenetic assays further revealed mitotic abnormalities in treated root meristems, underscoring a multifaceted mode of action. Molecular identification of the fungal strain and partial characterisation of the active fractions provide a blueprint for isolating novel phytotoxins and refining formulation strategies for field deployment.

Biological Control of Weeds Using Fungal Pathogens publication trend

The graph below shows the total number of articles in biological control of weeds using fungal pathogens across all publications each year (not limited to Nature Index journals).

Technical terms

Mycoherbicide: A bioherbicide formulation based on living fungal spores, mycelium or crude extracts designed to control weed species.

Phytotoxin: A biologically active compound produced by a microorganism that inhibits plant growth or disrupts specific physiological processes.

Necrotrophic pathogen: A fungus that kills host tissue and feeds on the dead matter, often secreting cell-wall-degrading enzymes and toxins.

Solid-state fermentation: A process in which fungi grow on moist solid substrates without free water, commonly used for production of spores and secondary metabolites.

Submerged fermentation: A method where fungal cultures are grown in liquid media, enabling controlled agitation and aeration for large-scale metabolite production.

References

1. Microbial Bioherbicides Based on Cell-Free Phytotoxic Metabolites: Analysis and Perspectives on Their Application in Weed Control as an Innovative Sustainable Solution. Plants (2024).
2. Physiological mechanism of action and partial separation of herbicide–active compounds from the Diaporthe sp. extract on Amaranthus tricolor L.. Scientific Reports (2023).
3. Modes of Action of Microbially-Produced Phytotoxins. Toxins (2011).
4. Achievements, Developments and Future Challenges in the Field of Bioherbicides for Weed Control: A Global Review. Plants (2022).
5. Potential Use of Biological Herbicides in a Circular Economy Context: A Sustainable Approach. Frontiers in Sustainable Food Systems (2020).