Preparation of multifunctional lignocellulosic microcapsules-protectants for high-efficiency green control of fusarium crown rot in wheat

The persistent outbreaks of Fusarium crown rot (FCR) pose significant challenges to food security, while traditional fungicide formulations provide short-term control and are associated with potential environmental safety risks. This study developed a stimulus-responsive, controlled-release fungicide system (MEZ@CM-VEAL) tailored to high-risk environmental conditions of FCR. It achieved an optimized loading capacity of 60.0 ± 1.7% and a loading efficiency of 87.0 ± 2.4%, with an average particle size of 454.8 nm. MEZ@CM-VEAL enhanced metconazole (MEZ) utilization during application through pH/enzyme-triggered controlled release, improved photostability, and enhanced horizontal migration in soil. In vitro antifungal activity tests showed that MEZ@CM-VEAL exhibited inhibitory effects on Fusarium pseudograminearum comparable to commercial formulations. Subsequent pot experiments confirmed the long-lasting effectiveness of MEZ@CM-VEAL in controlling FCR, with inhibition rates against F. pseudograminearum 46.7% and 30.7% higher than those of MEZ technical (MEZ TC) and commercial suspension concentrate (MEZ SC), respectively. Furthermore, MEZ@CM-VEAL exhibited significantly lower toxicity, with reductions of 2.4- and 2.3-fold to zebrafish, and 6.0- and 7.2-fold to earthworms, compared to MEZ TC and MEZ SC, respectively. This approach not only provides long-lasting protection against diseases and reduces pesticide usage, but also minimizes negative impacts on the ecological environment, thereby promoting sustainable agricultural development.