Ionic liquids as a novel class of herbicides

Overview

This research proposes ionic liquids (ILs) as a novel class of herbicides for agricultural weed management. Ionic liquids are salts that remain molten at room temperature and have previously been developed for biomass deconstruction in biofuel production. The researcher's hypothesis is that these same ionic liquids can disrupt the plant cuticle and cell wall of living plants, functioning either as standalone broad-spectrum herbicides or as adjuvants that enhance the effectiveness of existing chemical herbicides at lower application concentrations.

The ionic liquids under investigation are low-toxicity molecules that can be derived from biological sources, making them attractive candidates for sustainable crop protection. Preliminary laboratory tests on Arabidopsis and sorghum seedlings demonstrated wilting and death following surface application of low millimolar concentrations of ionic liquid, with consistent results across three independent trials.

Technical specifications

Core technology:

• Ionic liquids, specifically cholinium lysinate (CL), applied as spray treatments to plant surfaces
• Mechanism of action: disruption of the plant cuticle and cell wall
• Low millimolar application concentrations effective in preliminary trials
• Derived from biologically sourced, low-toxicity precursor molecules

Potential applications:

• Standalone broad-spectrum herbicide for grass and broadleaf weed control
• Adjuvant to enhance activity of existing commercial herbicides, potentially reducing required application rates
• Target weed species for upcoming field validation include rye grass, canola, wild radish, and milk thistle

Research approach:

• Test plot evaluation under field conditions at the University of Adelaide
• Comparison of ionic liquid efficacy alone versus in combination with existing herbicides
• Assessment of synergistic effects to determine whether lower herbicide concentrations can achieve equivalent or superior weed control

Technology readiness level

This technology is at an early research and validation stage. Proof-of-concept has been established through three replicated laboratory experiments on Arabidopsis and sorghum seedlings, demonstrating consistent wilting and mortality at low millimolar concentrations. The research team has now relocated to the University of Adelaide, where collaborators with expertise in weed management and access to dedicated test plot facilities have been engaged. Planned next steps include rigorous field-condition testing on multiple Australian weed species and evaluation of ionic liquid- herbicide combination strategies. Further development will require scaled-up efficacy data, toxicology profiling, formulation optimization, and regulatory assessment before commercial deployment can be considered.