Jianguo Feng

Pyrazole compounds have diverse structures and various biological activities, and thus play a significant role in the development of new pesticides.

Developing zinc oxide-based nano-bactericides as alternatives to conventional chemical bactericides for controlling rice bacterial diseases has become a major research focus. In this study, ZnO nanoparticles were initially surface-modified and subsequently covalently conjugated with chitooligosaccharide (COS) via imine bonds to get a pH-responsive zinc oxide–chitooligosaccharide (ZnO–COS) delivery system. A series of physicochemical characterizations, including FTIR, UV-vis, XRD, and TGA, confirmed the successful synthesis of ZnO–COS NPs. Building on this foundation, the pH-responsive release behavior, foliar deposition performance, antibacterial activity, and biosafety of the nanoparticles were systematically investigated. The prepared ZnO–COS NPs exhibited pronounced acid-triggered Zn²⁺ release, together with enhanced wettability, spreadability, and retention on rice leaf surfaces, owing to COS incorporation. In both in vitro and in vivo assays against Xanthomonas oryzae pv. oryzae (Xoo), ZnO–COS NPs demonstrated effective antibacterial activity associated with bacterial cell damage and the activation of antioxidant defense responses in plants. Consequently, ZnO–COS NPs achieved a preventive efficacy of 56.0% against rice bacterial blight, surpassing those of ZnO (33.3%) and COS (14.3%). Furthermore, safety assessment confirmed the good biocompatibility of ZnO–COS NPs towards rice seed germination and seedling growth. In summary, the synthesised ZnO–COS NPs integrated pH-responsive release, improved foliar deposition, and enhanced antioxidant capacity of rice, offering a promising strategy for mitigating bacterial diseases in rice.

Pest infestations devastate crop production, but chemical pesticides pose environmental and health risks. Eco-friendly biopesticides offer a solution, though limited by bioactive compound discovery. Here, we demonstrate that utilization of Yunnan’s Xishuangbanna—a cucumber diversity hotspot—to identify the local variety XSBN032, which retains desirable agronomic traits under aphid pressure. Metabolomic and GC–MS analyses identify farnesal—a volatile compound significantly enriched in XSBN032—under infested and non-infested conditions. Applying 0.33 g/L farnesal nanoemulsion to cucumber leaves rapidly disrupts aphid metabolism (within 6 h), impairing amino acid pathways and suppressing growth/reproduction, achieving 74.9% mortality within 24 h while preserving plant photosynthesis. Significantly, this treatment demonstrates high environmental safety: 0% earthworm mortality (500 mg/L, 7 days) and negligible effects on natural enemies (0% ladybird mortality; 7.41% green lacewing mortality). Our study establishes an integrated pipeline—from resistant germplasm discovery to biopesticide development—providing a sustainable pest control strategy. Leveraging multi-omics screening and smart delivery systems holds promise for future eco-efficient biopesticides.

BACKGROUND: Global agricultural sustainability faces considerable challenges owing to abiotic and biotic stresses, currently developing functional nanomaterials is an important way to alleviate the above stresses. Herein, ferrosoferric oxide (Fe ₃ O ₄ ) nanoparticles are modified with L‐arginine (Arg) and grafted with cinnamaldehyde (Cin) to prepare smart Fe–Arg–Cin nanoparticles (NPs) for alleviating drought and disease stresses. RESULTS: The structure and properties of Fe–Arg–Cin were characterized. Results revealed that the nanoparticles exhibit a uniform size distribution with 6.8% Cin loading. Fe–Arg–Cin NPs can effectively mitigate the inhibitory effects of drought stress on seed germination and seedling growth for rice and wheat. In addition, the in vitro and in vivo antifungal assays demonstrated that Fe–Arg–Cin NPs has potent antifungal activity against rice sheath blight ( Rhizoctonia solani ) and wheat sharp eyespot ( Rhizoctonia cerealis ). Moreover, biosafety evaluation showed that compared with Cin treatment, Fe–Arg–Cin NPs treatment remarkably reduces toxicity to zebrafish, human liver cells and soil microbial communities. CONCLUSION: The Fe–Arg–Cin NPs could not only improve the resistance of rice and wheat to drought stress and enhance the control effect against agricultural pathogens, but also ensures safety for non‐target organisms. This platform provides a promising strategy for improving crop resistance under drought and disease conditions. © 2026 Society of Chemical Industry.

Stable nanoemulsions with fine droplets reduce organic solvent use and improve the dispersion of hydrophobic pesticide. However, current studies on deltamethrin nanoemulsion lack systematic formula optimization, performance evaluation and biosafety assessment. This study developed a stable deltamethrin nanoemulsion (Del@Ne) and tested its physicochemical properties, insecticidal activity and non-target safety. In 2025, the effects of surfactant ratio, dosage, preparation temperature and emulsification method on emulsion stability was systematically investigated. The optimal formula contained an active ingredient (2.5% deltamethrin), a surfactant ratio of 8:1 (#601:#500), a 6% surfactant dosage, a 17.25% oil phase (S-100:DMF = 20:3), and deionised water filled to 100%, prepared by adding deionised water to an oil phase containing deltamethrin and surfactants at 40 °C. Del@Ne exhibited small droplet size and good storage stability (TSI ≈ 1), which had better wettability on peach leaves with contact angle falling from 40.4° to 21.6° in 120 s. Del@Ne also gave higher toxicity against Myzus persicae (LC₅₀ = 66.85 mg L⁻¹) than Del@EC (80.69 mg L⁻¹), while showing lower toxicity to zebrafish, earthworms and Harmonia axyridis, as well as better biocompatibility with human L02 hepatocytes. These results provide references for rapid screening of nanoemulsion formulation parameters and also offer insights for the efficient utilization of hydrophobic pesticides.

BACKGROUND: Pretilachlor (PR), a pre‐emergence herbicide crucial for rice weed management, is prone to rapid degradation and poses significant environmental risks, necessitating frequent applications. This study aims to develop an environmentally friendly carboxymethyl chitosan (CMCS)/Cu ²⁺ hydrogel delivery system that provides controlled release, enhances application efficacy, and mitigates ecological impacts while utilizing biowaste‐derived materials. RESULTS: CMCS hydrogel particles crosslinked via Cu ²⁺ coordination achieved a PR loading capacity (LC) of 13.70 ± 0.32%. The system displayed pH‐responsive behavior with maximum swelling (429%) at pH 8, enabling sustained PR release (51.2% over 80 h) and rapid biodegradation (83.9% mass loss within 7 days). At an agronomically relevant dosage of 500 g a.i. (active ingredient) ha ⁻¹ , the hydrogel formulation provided effective Echinochloa crus‐galli control comparable to commercial standards while eliminating rice phytotoxicity. Ecotoxicity assessments revealed significantly reduced environmental risks, with LC ₅₀ values of 0.60 mg L ⁻¹ for Danio rerio (1.7‐fold safer than emulsifiable concentrate (EC)) and >1600 mg kg ⁻¹ for Eisenia fetida . CONCLUSION: This study demonstrates the feasibility of utilizing CMCS/Cu ²⁺ hydrogel particles as a controlled‐release delivery system for PR in rice cultivation. The developed formulation provides sustained herbicide release aligned with early weed growth stages, reduced non‐target toxicity, and enhanced biodegradability compared to conventional formulations. While further field validation is needed, this approach offers a promising foundation for developing more environmentally compatible pesticide delivery systems that could potentially reduce application frequency and environmental loading in rice production. © 2026 Society of Chemical Industry.

Drought stress causes a significant accumulation of reactive oxygen species (ROS) in crops, inhibiting their growth and development and threatening food security. This study constructs cerium-based metal-organic frameworks (CeMs) encapsulated with polydopamine (PDA), effectively eliminating ROS (O₂^•-, H₂O₂, ·OH, DPPH·, and ABTS^·+). Experiments showed that CeMs@PDA exhibits superior wettability and outstanding translocation capabilities in wheat and rice. Under drought conditions, CeMs@PDA (12.5 mg L^-1, 100 mg L^-1) significantly increased the vigor index (71.84%, 224.83%) of seeds (wheat, rice). The application of 25 and 100 mg L^-1 CeMs@PDA significantly alleviated drought-induced growth inhibition in wheat and rice seedlings, respectively. The inhibition of stem and root growth decreased from 28.07% and 38.15% to 3.72% and 4.43% in wheat seedlings, and the inhibition declined from 25.33% and 30.83% to 2.89% and 5.30% in rice seedlings, respectively. In addition, CeMs@PDA significantly increased the level of antioxidant enzyme activities in wheat and rice and showed better biosafety. This study opens valuable pathways for sustainable agriculture under water-limited conditions.