Preparation of chitosan/sodium tripolyphosphate@nano‐silica sol microcapsule suspensions and their application in soybean cyst nematode control

Abstract

Fosthiazate is a common insecticide for root-knot nematode control, but it has a short shelf life and is prone to decomposition. In order to improve the stability and prolong the release time, this experiment used the ionic gel method to cross-link chitosan with sodium tripolyphosphate and added nano-silica sol to prepare microcapsules suspensions. The optimal preparation parameters for the preparation of chitosan/sodium [email protected] sol microcapsulated suspensions were optimized by single factor experiments and response surface analysis, and the encapsulation efficiency reached 61.3%. The highest control effect in greenhouse pots can reach 84.1%, and the optimal concentration was 2 g/m2 mixed with soil, which increased stem length, root length and fresh weight by 81.1%, 47.7% and 62.5%. The study showed that the microcapsules of chitosan cross-linked with sodium tripolyphosphate and added with nano-silica sol could significantly prolong the release of Fosthiazate, which also provided a positive effect on soybean cyst nematode control.