Dual pH-Responsive Multifunctional Double Network Hydrogels for Efficient and Sustainable Control of Tomato Bacterial Wilt
Here, we report the design, preparation, and field use of a dual pH-responsive multifunctional double network (DN) hydrogel for the targeted and sustainable control of bacterial wilt. The gel consists of a primary network of pH-responsive carboxylated agarose chelating Zn2+ ions and a secondary network formed by the self-assembly of L-phenylalanine and Zn2+. Under acidic conditions (pH <= 5), which promote R. solanacearum growth, the primary network loosens to release zhongshengmycin, a broad-spectrum antibacterial biopesticide, and Zn2+, while the secondary network disassembles to release additional bioactive components (Phe and Zn2+). This dual-triggered release achieves a combined antibacterial effect, enhances plant growth, and activates plant disease resistance pathways. A simple root application protects plants for up to 14 days, and field experiments demonstrate disease control for up to 30 days, significantly preserving tomato yield. This study presents a sustainable, effective system for managing bacterial wilt and highlights the potential of smart hydrogels in crop protection and production.