Efficient delivery of the herbicide quinclorac by nanosuspension for enhancing deposition, uptake and herbicidal activity.

ABSTRACT

BACKGROUND: The presence of barnyardgrass poses a threat to global food security by reducing rice yields. Currently, herbicides are primarily applied for weed management. However, the effectiveness of herbicide deposition and uptake on barnyardgrass is limited as a consequence of the high wax content on leaves, low water solubility and extreme lipophilicity of herbicides. Therefore, it is imperative to develop novel formulations for efficient delivery of herbicides to improve herbicidal activity and reduce dosage. RESULTS: We successfully prepared nanosuspension(s) (NS) of quinclorac through the wet media milling technique. This NS demonstrates excellent physical stability and maintains nanoscale during dose transfer. The deposition concentration and uptake concentration of NS on barnyardgrass were 3.84-4.47- and 2.11-2.58-fold greater than those traditional formulations, respectively. Moreover, the NS exhibited enhanced herbicidal activity against barnyardgrass at half the dosage required by conventional formulations without compromising rice safety. CONCLUSIONS: These findings suggest that NS can effectively facilitate the delivery of hydrophobic and poorly water-soluble herbicide active ingredients, thereby enhancing their deposition, uptake and bioactivity. This study expands the potential application of NS in pesticide delivery, which can provide valuable support for optimizing pesticide utilization, improving economic efficiency and mitigating environmental risks. © 2024 Society of Chemical Industry.