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.

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Interactive release formulations are one of the best strategies for enhancing pesticides usage. A 112 nm α-amylase enzyme-responsive nanosystem loaded with abamectin (ABM) was synthesized by attaching carboxymethyl starch (CMS) to the surface of hollow mesoporous silica (HMS) to improve ABM insecticidal activity and photostability. ABM-loaded HMS–CMS characteristics were tested. ABM release behavior under different pH levels and in the presence or absence of α-amylase enzyme was investigated. The ultraviolet (UV) protection ability and the insecticidal activity against one of the model insects, Spodoptera littoralis, were examined. The adhesion properties of ABM-loaded HMS–CMS on corn leaves have been tested. The prepared ABM-loaded HMS–CMS presented a high loading efficacy of up to 24.77% and enzymatic release dependency of up to 88.34% after 17 days of adding α-amylase enzyme. After 60 h of UV radiation, only 17.7% of the loaded ABM into HMS–CMS has deteriorated. ABM-loaded HMS–CMS showed better insecticidal activity against S. littoralis than abamectin commercial formulation (ABM-EC). After 14 days, the LC50 of ABM-loaded HMS–CMS was 51.7% lower than that of ABM-EC. The prepared ABM-loaded HMS–CMS showed excellent adhesion on corn leaves. We recommend using such formulations to achieve better and sustainable farming.

BACKGROUND: As the use of diamide insecticides on corn continues to increase, there is growing concern about their residue levels on corn and dietary risks to populations. In this study, the distribution, dispersion and transfer efficiency of two diamide insecticides (tetrachlorantraniliprole (TCAP) and cyantraniliprole (CNAP)) in different parts of corn and soil were investigated in a 1-year field trial in Guangzhou and Lanzhou using two different application methodsspray and drip irrigation, respectivelyand the dietary risk of the insecticides to different consumer populations was assessed under the two application methods. RESULTS:The results showed that drip irrigation had a longer persistence period than spraying, and there was a hysteresis in the absorption distribution of the agent in different parts of corn, which was gradually transferred to the leaves after absorption from the roots. The average TE 1 (transfer efficiency) and TE 2 were 0.230-0.261 and 1.749-1.851 for TCAP and 0.168-0.187 and 2.363-2.815 for CNAP, respectively. At corn harvest, both TCAP and CNAP were below detectable levels in soil and corn. For different consumer populations, hazard quotients ranged from 0.001 to 0.066 for TCAP and from 0.003 to 0.568 for CNAPboth well below 100%.CONCLUSION: This study indicates that TCAP and CNAP applied by spray or drip irrigation are safe for long-term risk of human intake and also provides guidance for the use of both insecticides in agricultural production to control corn pests, especially in arid and semi-arid areas.

In this work, an enzyme-responsive nanovehicle for improving captan (CAP) contact fungicide bioactivity and translocation in plant tissues was synthesized (CAP-MSNs-β-glucan) by attaching β-glucan to the outer surface of mesoporous silica nanoparticles. CAP-MSNs-β-glucan properties were tested by FTIR, ζ-potential, DLS, XRD, TGA, FE-SEM, and HR-TEM. Cargo protection ability of CAP-MSNs-β-glucan from photolysis and hydrolysis was examined in comparison to CAP commercial formulation (CAP-CF). CAP-MSNs-β-glucan distribution in plant tissues, bioactivity against Fusarium graminearum , and biotoxicity toward zebrafish ( Danio rerio ) were tested and compared with that of CAP-CF. CAP-MSNs-β-glucan results showed good loading efficacy reaching 18.39% and enzymatic-release dependency up to 83.8% of the total cargo after 20 days of β-glucan unsealing. CAP-MSNs-β-glucan showed significant release protection under pH changes. MSNs-β-glucan showed excellent CAP protection from UV. CAP-MSNs-β-glucan showed better distribution in corn tissues and 1.28 more inhibiting potency to Fusarium graminearum than CAP-CF. CAP-MSNs-β-glucan showed 1.88 times lower toxicity than CAP-CF to zebrafish after 96 h of treatment. We recommend using such formulations to overcome shortcomings of contact fungicides and achieve better and sustainable farming.