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BACKGROUND: The development of stimulus-responsive and photothermally controlled-release microcapsule pesticide delivery systems is a promising solution to enhance the effective utilization and minimize the excessive use of pesticides in agriculture.RESULTS: In this study, an AVM@CS@TA-Fe microcapsule pesticide delivery system was developed using avermectin as the model drug, chitosan and tannic acid as the wall materials, and tannic acid-Fe complex layer as the photothermal agent. The optical microscope, scanning electron microscope, transmission electron microscope, and Fourier-transform infrared spectroscope were used to characterize the prepared microcapsule. The slow-release, UV-shielding, photothermal performance, and nematicidal activity of the microcapsule were systematically investigated. The results showed that the system exhibited excellent pH-responsive and photothermal-sensitive performances. In addition, the UV-shielding performance of the delivery system was improved. The photothermal conversion efficiency (η) of the system under the irradiation of near-infrared (NIR) light was determined to be 14.18%. Moreover, the nematicidal activities of the system against pine wood nematode and Aphelenchoides besseyi were greatly increased under the irradiation of light-emitting diode (LED) simulated sunlight.CONCLUSION: The release of the pesticide-active substances in such a pesticide delivery system could be effectively regulated with the irradiation of NIR light or LED-simulated sunlight. Thus, the developed pesticide delivery system may have broad application prospects in modern agriculture fields.

Preparation of chlorfenapyr microcapsules with a degradable polylactide-based polyurethane wall material is described in this paper, the microcapsules improve the utilization rate of chlorfenapyr and are safe for humans and the environment.

A photothermal controlled-release microcapsule pesticide delivery system was constructed using chitosan and polydopamine as the wall materials to encapsulate avermectin, the utilization rate of avermectin was improved.