No abstract

Site-specific pesticide delivery is one of the potential strategies to enhance the use of fungicides and decrease undesirable environmental damages. Herein, a β-glucanase enzyme-responsive nanovehicle used for controlling chlorothalonil (CHT) release in the plant vascular system was synthesized (CHT@MSNs-β-glucans) by attaching β-glucans extracted from the yeast cell wall on MSNs pore rims for the management of rice blast (Magnaporthe grisea). CHT@MSNs-β-glucans characteristics were examined by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transfer infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), N 2 isotherm, and Zetasizer. The obtained results showed that CHT@MSNs-β-glucans have excellent enzymatic release dependency, an outstanding loading efficacy of 24.99%, remarkable protection from acidic and alkaline conditions, and UV shielding ability up to 3 times greater than that of CHT commercial product (CHT-WP). CHT@MSNs-β-glucans showed excellent bioactivity against rice blast compared with CHT-WP. Moreover, CHT@ MSNs-β-glucans showed better distribution in different tissues of rice plants. Additionally, CHT@MSNs-β-glucans showed 2.6 times lower toxicity to Daphnia magna and exhibited lower changes in soil microbial abundance than CHT-WP. This study provides significant sustainable management of plant pathogens for better farming.

No abstract

No abstract

Traditional pesticide formulations show poor utilization and environmental safety due to their low foliage adhesion and large auxiliaries. In this study, a novel and environment-friendly indoxacarb formulation was prepared to improve the pesticide’s utilization rate, target control characteristics and ecological security. Indoxacarb-loaded waterborne polyurethane–sodium alginate (PU/SA) nanoemulsions with film forming properties, alkaline responsive release, high effectiveness against Spodoptera litura, and reduced acute contact toxicity for nontarget organisms were successfully prepared. The colloidal properties, swelling and release behaviors, leaf adhesion, degradation dynamics and bioactivity assay of the indoxacarb-loaded PU/SA nanoemulsions were determined. Results showed that the obtained indoxacarb-loaded microcapsule particulates were approximately 57 nm in diameter, electronegative −45.9 mV, and uniformly dispersed in the nanoemulsions. The dried latex films of PU/SA in the alkaline environment revealed better responsive swelling and release characteristics than those in acidic and neutral conditions. Compared with a commercial emulsifiable concentrate, the indoxacarb-loaded PU/SA nanoemulsions were useful for the targeted control of S. litura, which have alkaline gut and showed reduced acute contact toxicity to Harmonia axyridia. Furthermore, the PU/SA formulation had better foliage adhesion and indicated the property of controlled-release and a persistent effect.