Thiamethoxam loaded glycine/iron( III ) controlled‐release granules: enhanced pesticide utilization rate and improved crop physiological status

BACKGROUND: Neonicotinoid pesticides have attracted much attention in pest control due to their excellent systemic properties and high insecticidal activity. Functional carriers based on controlled-release technology can precisely regulate the release of pesticides, improve utilization rate and reduce environmental risks, and have become an important research direction for optimizing root application strategies. RESULTS: In this study, thiamethoxam (TMX) was employed as a model pesticide. A dual binding strategy was adopted to prepare TMX core-shell controlled-release granules (TMX-GR). By adjusting parameters such as iron(III) concentration, glycine (Gly) concentration, material ratio, and particle size, products with distinct release properties were successfully fabricated. The results showed that the TMX-GR prepared successfully had a pesticide-loading efficiency of 50.30% and exhibited obvious controlled-release behavior. Glasshouse potted plants showed that the TMX-GR were more persistent and significantly improved pesticide utilization rate compared to 30% TMX suspension concentrate (30% SC) and 3% TMX granules (3% SP). In addition, the addition of Gly can improve the growth state of Brassica oleracea var. capitata L. seedlings and significantly increase the dry weight and soluble sugar content. CONCLUSION: In summary, this delivery system has a simple preparation process, demonstrating both excellent insecticidal activity and plant growth-regulation functions, thereby providing an innovative design concept for developing functional controlled-release formulations. © 2025 Society of Chemical Industry.