Exploring the Antifungal and Phytotoxic Activity of Polyvinyl Alcohol Hydrogels Incorporated With Essential Oils

Agriculture is an important sector of the economy but consumes significant amounts of water, a precious and limited natural resource. However, superabsorbent polymers combined with essential oils (EO) can be used to obtain sustained release of nutrients and improved soil water retention capacity by hydrogel, and they act as a repellence in the crops of the natural farm crop enemies. Were synthesized, poly(vinyl alcohol) (PVOH) hydrogels, with crosslinked organics acids (malic and tartaric) and EO incorporated (clove, orange, and vanilla), is a novel method to develop release control of compounds with specific applications and show their potential agricultural and aphicide applications. The results show the incorporation of EO in the PVOH hydrogels, using a sonication process seen in the FTIR and optical microscopy analysis, obtaining good performance compared to traditional surfactants. In the olfactometer bioassay, the hydrogels show a repellent effect on Myzus persicae, under the synthesis time and EO specifically used, with a promising result for tartaric acid-based hydrogels composed of Citrus chemical compounds except vanilla EO. To reduce germination and ecotoxicity, hydrogels decrease the germination and growth of plants, especially vanilla EO, showing inhibitory effects on onion and lettuce. All EO inhibited the mycelial growth of Aspergillus fumigatus, especially the samples with 2 h of the reaction. The hydrogels incorporated with clove, orange, and vanilla EO could be a promising alternative to natural agents to repel crop enemies' and provide antimicrobial and antifungal activity in agricultural systems.