Phosphate-modified cellulose/chitosan with high drug loading for effective prevention of rice leaffolder ( ) outbreaks in fields

The continuous infestation of pests has seriously affected rice growth, yield and quality. How to reduce the use of pesticides and effectively control insect pests is a bottleneck problem. Herein, based on hydrogen bonding and electrostatic interactions, we posed a novel strategy to construct emamectin benzoate (EB) pesticide loading system using self-assembled phosphate-modified cellulose microspheres (CMP) and chitosan (CS). CMP provides more binding sites for EB loading and CS coating further enhances the carrier loading capacity up to 50.75 %, which jointly imparted pesticide photostability and pH-responsiveness. The retention capacity of EB-CMP@CS in rice growth soil reached 101.56-fold that of commercial EB, which effectively improved the absorption of pesticides during rice development. During the pest outbreak, EB-CMP@CS achieved effective pest control by increasing the pesticide content in rice stems and leaves, the control efficiency of the rice leaffolder (Cnaphalocrocis medinalis) reached 14-fold that of commercial EB, and could maintain the effective pest control effect during the booting stage of rice. Finally, EB-CMP@CS-treated paddy fields had improved yields and were free of pesticide residues in the rice grain. Therefore, EB-CMP@CS achieves effective control of rice leaffolder in paddy fields and has potential application value in green agricultural production.