Self-Assembled Sphere Covalent Organic Framework with Enhanced Herbicidal Activity by Loading Cyhalofop-butyl

Mechanochemically synthesized covalent organic frameworks as catalysts for the Suzuki-Miyaura coupling reaction

In this study, we present a mechanochemically assisted rapid synthesis of highly crystalline covalent organic frameworks (COFs), specifically the MC-Tab-Dva COF and the MC-Tz-Dva COF, achieved in an exceptionally short time of 30 to 60 min. Additionally, the synthesized COFs were post-modified to incorporate Pd(II), resulting in Pd(II)-containing COFs that demonstrated excellent catalytic activity in Suzuki-Miyaura coupling reactions.

Environmentally Friendly Sustained-Release Antifungal Cyclodextrin Inclusion Complex Nanofibers for Controlling Fungi

The development of hydrophobic pesticide formulations remains constrained by complicated manufacturing processes, excessive reliance on organic solvents, and indispensable surfactants. The practical application of dimethomorph (DIM) is hindered by its hydrophobic nature, posing risks to nontarget organisms. Inspired by the uptake of nanomaterials by plants, DIM was encapsulated in the cyclodextrin (CD) cavity to optimize its water-solubility and the sustained-release rate. The spatial confinement effect of CD could facilitate the thermostability of DIM. DIM/CD inclusion complex solutions were electrospun to fabricate nanofibers with bead-free and smooth morphology. As predicted, the release of DIM/CD inclusion complex nanofibers reached plateaus with accumulative release values of approximately 75%. The antifungal activity of DIM/CD inclusion complex nanofibers possesses much higher than DIM for controlling Rhizoctonia solani and Haematonectria hematococco, thereby enhancing its antifungal bioactivity and reducing pesticide spraying frequency. The inhibition rates of Rhizoctonia solani by DIM/HPβCD and DIM/HPγCD inclusion complex nanofibers are found to be 55.8% and 53.6% within 144 h, respectively. This work explores the feasibility of inclusion of complex nanofibers as a delivery platform for application in sustained agriculture production.

Size Effects of Nanoenabled Agrochemicals in Sustainable Crop Production: Advances, Challenges, and Perspectives

Nanoenabled agrochemicals mainly including nanopesticides and nanofertilizers based on nanotechnology play a crucial role in plant protection and food security. These agrochemicals exhibit high dose delivery efficiency and biological activity due to their unique nanoscale properties. However, nanoscale properties can also be a double-edged sword, posing potential risks to both humans and the environment. As nanoenabled agrochemicals become more widely used, it is essential to have an objective and comprehensive discussion of the size effects of these agrochemicals. In this paper, we reviewed the research progress on the size effects of nanoenabled agrochemicals in terms of dose delivery, biological activity, and nontarget safety. We investigated the complex factors affecting size effects and sought to draw insights from research in biomedicine, engineering, food, and other relevant fields. Based on the literatures review, it could be concluded that "the smaller the better" is not always the case. We further outlooked the development prospects of studying the size effects of nanoenabled agrochemicals, emphasizing the necessity for thorough and in-depth research while critically identifying key issues that need to be addressed. In conclusion, a proper comprehension of the size effects of nanoenabled agrochemicals bridges the gap between the scientific community and industry, bolstering the role in advancing sustainable agriculture.

Design of highly leaf-adhesive and anti-UV herbicide nanoformulation for enhanced herbicidal activity

INTRODUCTION

Conventional pesticide formulations have been widely used to boost agricultural productivity, but their weak foliar adhesion and instability under UV light during spraying lead to low utilization rates and potential environmental and health hazards. To counter these challenges, the development of nanoformulations represents a pivotal strategy. These advanced formulations are designed to enhance the efficacy of active ingredients (AIs) and reduce ecological impacts, thereby addressing the need for sustainable agricultural development.

OBJECTIVES

The study aims to fabricate a highly leaf-adhesive and anti-UV herbicide nanoformulation, designed to enhance the herbicidal activity and utilization rates of AIs.

METHODS

Herein, the herbicide nanoformulations (Called CB@MSNs-TA-Fe) are synthesized by incorporating cyhalofop-butyl into tannic acid-Fe (III) ions-coated functionalized mesoporous silica. The foliar retention performance of the samples was assessed integrating SEM observation and HPLC analysis.

RESULTS

The CB@MSNs-TA-Fe with rough outer surface displays typical core-shell structure featuring an average diameter of about 118 nm. After amino modification, the CB@MSNs-TA-Fe shows enhanced loading rate for CB (14.4 ± 0.2 %) and superior thermal stability. The release rate of CB within CB@MSNs-TA-Fe under acidic conditions is higher compared to that under alkaline and neutral conditions. Upon UV irradiation, the half-life of CB within CB@MSNs-TA-Fe nanoparticles is 12.4 times higher than that of CB technical (CB TC). Enhanced foliar adhesion of CB@MSNs-TA-Fe on hydrophobic leaf surfaces is observed, which can effectively mitigate the risk of wash-off by rainfall. The CB@MSNs-TA-Fe displays enhanced herbicidal efficacies against barnyard grass under UV irradiation or simulated rainwater scouring, compared with CB TC and CB oil dispersion. Furthermore, the TA-Fe-coated MSNs-NH2 nano-carrier (MSNs-TA-Fe) reveals excellent biosafety on rice, zebrafish, and earthworms.

CONCLUSION

The developed TA-Fe-functionalized herbicide nanoformulations, with high foliar adhesion and anti-UV properties, effectively improve the utilization efficiency of AIs, thus offering innovative solutions for the development of efficient pesticide formulations.

Redox-Responsive Nanopesticides Based on Natural Polymers for Environmentally Safe Delivery of Pesticides with Enhanced Foliar Dispersion and Washout Resistance

Based on the modified cross-linking of the degradable natural polymers chitosan oligosaccharides (COS) and gelatin (GEL) via introduction of a functional bridge 3,3'-dithiodipropionic acid, this study constructed an environmentally responsive dinotefuran (DNF) delivery system (DNF@COS-SS-GEL). The introduction of the disulfide bond (-S-S-) endowed DNF@COS-SS-GEL with redox-responsive properties, allowing for the rapid release of pesticides when stimulated by glutathione (GSH) in the simulated insect. Compared with commercial DNF suspension concentrate (DNF-SC), DNF@COS-SS-GEL showed superior wet spreading and retention performance on cabbage leaves with a reduced contact angle (57°) at 180 s and 4-fold increased retention capacity after rainfall washout. Nanoencapsulation effectively improved the UV-photostability with only a 31.4% decomposition rate of DNF@COS-SS-GEL at 96 h. The small scale and large specific surface area resulted in excellent uptake and transportation properties in plants as well as higher bioactivity against Plutella xylostella larvae. This study will help promote sustainable agricultural development by reducing environmental pollution through improved pesticide utilization.

Efficient delivery of the herbicide quinclorac by nanosuspension for enhancing deposition, uptake and herbicidal activity

BACKGROUND

The presence of barnyardgrass poses a threat to global food security by reducing rice yields. Currently, herbicides are primarily applied for weed management. However, the effectiveness of herbicide deposition and uptake on barnyardgrass is limited as a consequence of the high wax content on leaves, low water solubility and extreme lipophilicity of herbicides. Therefore, it is imperative to develop novel formulations for efficient delivery of herbicides to improve herbicidal activity and reduce dosage.

RESULTS

We successfully prepared nanosuspension(s) (NS) of quinclorac through the wet media milling technique. This NS demonstrates excellent physical stability and maintains nanoscale during dose transfer. The deposition concentration and uptake concentration of NS on barnyardgrass were 3.84-4.47- and 2.11-2.58-fold greater than those traditional formulations, respectively. Moreover, the NS exhibited enhanced herbicidal activity against barnyardgrass at half the dosage required by conventional formulations without compromising rice safety.

CONCLUSIONS

These findings suggest that NS can effectively facilitate the delivery of hydrophobic and poorly water-soluble herbicide active ingredients, thereby enhancing their deposition, uptake and bioactivity. This study expands the potential application of NS in pesticide delivery, which can provide valuable support for optimizing pesticide utilization, improving economic efficiency and mitigating environmental risks. © 2024 Society of Chemical Industry.

A pH-responsive MOF-functionalized hollow mesoporous silica controlled herbicide delivery system exhibits enhanced activity against ACCase-herbicide-resistant weeds

BACKGROUND

Weeds grow aggressively in agricultural fields, leading to reduced crop yields and an inability to meet the growing demand for food. Herbicides are currently the most effective method for weed control. However, the overuse of herbicides has resulted in the evolution of resistance mutants and has caused environmental pollution. Therefore, new technologies are urgently required to address this global challenge.

RESULTS

We report a copper-benzene-1,4-dicarboxylate metal organic framework (Cu-BDC MOF)-functionalized carboxyl hollow mesoporous silica (HMS-COOH) delivery system for the pH-controlled release of the acetyl-CoA carboxylase (ACCase)-inhibiting herbicide quizalofop-p-ethyl (QE). The delivery system (QE@HMS@Cu-BDC) enabled the efficient control of barnyard grasses that are susceptible and resistant to ACCase-inhibiting herbicides, which showed 93.33% and 88.33% FW control efficacy at 67.5 g ha-1 , respectively. With the lowest pH value (3), QE and copper ion were released slowly to total 70.30% and 78.55% levels (respectively) from QE@HMS@Cu-BDC after 89 h. QE@HMS@Cu-BDC showed better absorption, conduction, transportation and ACCase activity inhibition performance than that of QE emulsifiable concentrate (EC) in both susceptible and ACCase-herbicide resistant barnyard grasses. In addition, with the safener effect of carrier HMS@Cu-BDC and the aid of the safener fenchlorazole-ethyl (FE), the application of QE@HMS@Cu-BDC was shown to mitigate the damage caused by QE to rice plants.

CONCLUSION

This work found that the new material HMS-COOH@Cu-BDC can be used to mitigate herbicide-induced oxidative stress and improve rice plant safety. Futhermore, the QE@HMS-COOH@Cu-BDC constructed in this research might be used as an efficient nanopesticide formulation for weed controls in paddy rice fields. © 2023 Society of Chemical Industry.

Particle Size Effect of Cyetpyrafen Formulation in the Pesticide Transmission Process and Its Impact on Biological Activity

Cyetpyrafen is a compound that lacks inherent uptake and systemic translocation activity. If mites do not come into direct contact with the pesticide solution on leaves, the efficacy cannot be achieved. Controlling the particle size can potentially play a crucial role in the manifestation of efficacy. In this study, high-throughput formulation technology was used to systematically screen a large number of adjuvants to obtain cyetpyrafen formulations. The particle size of the active ingredient in the formulation was measured. By examining the dynamic light scattering and contact angle, we simulated the actual process of the efficacy transmission of cyetpyrafen formulations against Tetranychus cinnabarinus. Our results showed that the activity of cyetpyrafen increases as the particle size decreases, suggesting that reducing the particle size can enhance the coverage and deposition on crop leaves, and further improve the dispersion efficiency and enhance spreading capabilities. Furthermore, controlling the particle size at 160 nm resulted in an LC50 value of 0.2026, which is approximately double than that of the commercial product. As a novel pesticide for mites, our study presents the most effective cyetpyrafen formulation in practice. Our findings provide valuable insights into controlling other mite species that pose a threat to agricultural products.

Formulation and Characterization of Matrine Oil Dispersion to Improve Droplet Wetting and Deposition

The unreasonable use of chemical pesticides has caused serious damage to crops and the ecological environment. The botanical pesticide matrine has attracted attention as an environmentally friendly pesticide. Compared with traditional spraying methods, unmanned aerial vehicle (UAV) spraying has the advantages of safety, rapidity, uniform droplets, low dosages, and no terrain or crop restrictions. In this study, matrine OD was prepared according to the application requirements of flight prevention preparations using three different emulsifiers. The stability, wettability, particle size and distribution, and spraying performance of matrine OD were studied. The results indicated that when the amount of emulsifier was 8%, the three types of matrine OD had good stability. The stability, wettability, particle size and distribution, and spray performance of the suspension prepared using emulsifier VO/03 were better than the other two emulsifiers. Therefore, matrine OD prepared using 8% VO/03 could be used for ultra-low-volume sprays and aerial applications. In this study, we provide a theoretical basis and technical guidance to develop pesticide formulations for aerial applications.