A Zn-MOF with ultra-high encapsulation efficiency modified with pectin for targeted fungicide delivery against Fusarium graminearum

Soil-borne diseases severely threaten global crop production and urgently require pesticide formulations with targeted effects to improve control efficiency. In this study, a one-pot synthesis method combined with solvent ratio screening was used to successfully prepare Pyr@ZIF-NH₂ loaded with pyraclostrobin (Pyr) achieving a high encapsulation efficiency of 97.42 % and a pesticide loading rate of 20.59 %. The Pyr@ZIF-NH 2 was modified with pectin to obtain Pyr@ZIF@P (119.4 nm), and its successful synthesis was confirmed through characterization. Pyr@ZIF@P enhanced the UV photostability of Pyr and effectively inhibited the growth of Fusarium graminearum , resulting in mycelial malformation. In vitro release studies showed significantly higher Pyr release under acidic, pectinase-rich conditions (mimicking infection sites) with cumulative releases rates of 83.1 % and 74.11 % within 72 h. Foliar application revealed that Pyr@ZIF@P improved foliar retention and promoted downward translocation compared to the commercial suspension, thereby enhancing the control of soil-borne diseases. Moreover, root deaching of Pyr@ZIF@P resulted in more substantial accumulation of active Pyr in the stem, thereby enhancing the control of Fusarium graminearum. Additionally, the zinc-based framework of Pyr@ZIF@P not only facilitates pesticide delivery but also contributes to enhanced root development in wheat seedlings. Taken together, this study presents a novel approach for controlling soil-borne diseases and supporting sustainable agricultural production.