Dual retention degradable polyester nanodelivery for enhanced fungicide utilization and targeted control of fusarium crown rot

Abstract Background In crop protection, two major challenges persist: the insufficient deposition of agrochemicals on target plants (such as foliar runoff and excessive migration in soil) and the environmental risks of conventional non‐degradable carriers. Results Here, a degradable polyester, poly(β‐amino ester) (PAE), was synthesized via Michael addition and employed for the first time in agrochemical nanodelivery. Difenoconazole‐loaded nanoparticles (215 nm, 32.5% loading) exhibited strong foliar adhesion, reduced soil migration, and enhanced photostability, thereby minimizing fungicide losses in both foliar spraying and soil application. The proton‐sensitive amines in PAE enabled acid‐responsive release matched to the acidic microenvironments of fusarium crown rot infection sites, while the intrinsic bioactivity of PAE provided synergistic antifungal effects. Pot experiments confirmed superior and prolonged control, achieving 51.2% disease suppression at 21 days compared with 32.7% for a commercial formulation. Biosafety evaluations demonstrated compatibility with wheat, reduced acute toxicity to earthworms, and environmentally benign degradation products. Conclusion This study establishes a sustainable nanodelivery strategy that integrates degradability, pH‐responsiveness, and dual adhesion into a single polyester platform. By enhancing fungicide utilization while reducing ecological risks, it highlights the potential of degradable polymers to advance cleaner and more effective management of soil‐borne diseases. © 2025 Society of Chemical Industry.