Eucalyptol-loaded microcapsules combined with Cynanchum komarovii extracts provide long-term and low-risk management of Chinese wolfberry (Lycium barbarum L.)

Abstract

Realizing eco-friendly, long-term, and low-risk aphid control on Lycium barbarum (medicinal cash crop) using a Cynanchum komarovii extracts and eucalyptus oil-loaded microcapsules (EOMCs) formulation compositions is viable. In this study, the aim is to optimize the composition of Cynanchum komarovii extracts and EOMCs formulation for effective control of aphids, the release of EOMCs was controlled by changing the cross-linking degree of the shell to match the aphid control characteristics of Cynanchum komarovii extracts. Four types of polyamines were used as cross-linking agents for the preparation of EOMCs by interfacial polymerization. The bioactivity, wettability, and field application efficacy of Cynanchum komarovii extracts and different EOMCs formulation compositions were evaluated. These EOMCs exhibited an encapsulation efficiency exceeding 85 %. The control efficiency of the formulation compositions of microcapsules with a moderate release rate and Cynanchum komarovii extracts on aphids remained at 62.86 %, while the control efficiency of the combination of microcapsules with the fastest and slowest rates with Cynanchum komarovii extracts was only 48.62 % and 57.11 %, respectively. The formulation compositions of Cynanchum komarovii extracts with all four types of EOMCs were found to be safe for Chinese wolfberry plants. Overall, by selecting appropriate polyamines during fabrication, the release rate can be effectively controlled to achieve sustainable and low-risk aphid control in Lycium barbarum through compounding with selected microcapsules.

Keywords: Chinese wolfberry; Cynanchum komarovii extracts; Essential oil; Microcapsules; Natural product pesticides.