Lignin/Surfactin\nCoacervate as an Eco-Friendly Pesticide\nCarrier and Antifungal Agent against Phytopathogen

Excessive usage of biologically toxic fungicides and\ntheir matrix\nmaterials poses a serious threat to public health. Leveraging fungicide\ncarriers with inherent pathogen inhibition properties is highly promising\nfor enhancing fungicide efficacy and reducing required dosage. Herein,\na series of coacervates have been crafted with lignin and surfactin,\nboth of which are naturally derived and demonstrate substantial antifungal\nproperties. This hierarchically assembled carrier not only effectively\nloads fungicides with a maximum encapsulation efficiency of 95% but\nalso stably deposits on hydrophobic leaves for high-speed impacting\ndroplets. Intriguingly, these coacervates exhibit broad spectrum fungicidal\nactivity against eight ubiquitous phytopathogens and even act as a\nstandalone biofungicide to replace fungicides. This performance can\nsignificantly reduce the fungicide usage and be further strengthened\nby an encapsulated fungicide. The inhibition rate reaches 87.0% when\n0.30 mM pyraclostrobin (Pyr) is encapsulated within this coacervate,\ncomparable to the effectiveness of 0.80 mM Pyr alone. Additionally,\nthe preventive effects against tomato gray mold reached 53%, significantly\nsurpassing those of commercial adjuvants. Thus, it demonstrates that\nutilizing biosurfactants and biomass with intrinsic antifungal activity\nto fabricate fully biobased coacervates can synergistically combine\nthe functions of a fungicide carrier and antifungal agent against\nphytopathogens and guarantee environmental friendliness. This pioneering\napproach provides deeper insights into synergistically enhancing the\neffectiveness of agrochemicals from multiple aspects, including fungicide\nencapsulation, cooperative antifungal action, and droplet deposition.