Toward Sustainable Pesticide Application: Bridging Efficacy and Food Safety.

Improving the adhesion and spreading of pesticides on plant surfaces is essential for maximizing efficacy, yet current approaches often exacerbate pesticide residues, posing risks to environmental and food safety. Sustainable alternatives are urgently needed to enhance pesticide utilization while minimizing collateral harm. Here, a fully bio-based pesticide delivery system is presented constructed from lignin coacervates-formed via hydrophobic and electrostatic interactions between aminated alkaline lignin and sodium lignosulfonate, both readily available industrial byproducts-and used for efficient encapsulation the hydrophobic pesticide abamectin. The resulting formulation improves pesticide retention on leaves, enhances resistance to ultraviolet degradation, and ensures strong adhesion and wetting, critical factors for reducing spray drift and runoff. Importantly, the delivery system enables pH- and laccase-triggered release, aligning with the biological environment of target pests and supporting controlled, prolonged action. By physically shielding the active ingredient, the coacervates reduce non-target exposure and ecological toxicity by a factor of two to three. Moreover, the formulation demonstrates superior removability under household washing, as it can be completely eliminated with only a few simple rinses, thereby substantially lowering the risk of foodborne residues. Overall, this work establishes a sustainable pesticide-delivery platforms that reconciles agricultural efficacy with environmental and food safety imperatives.