Environmentally-Friendly Alternative to Copper-Based Biocides

Abstract

University of Central Florida researchers have developed an environmentally-friendly alternative to copper (Cu)-based biocides, which are commonly used to treat plant diseases caused by bacteria, fungi or viruses. The UCF team created a novel composition that uses magnesium hydroxide nanoparticles to effectively inhibit and kill diseases such as Xanthomonas alfalfae, Pseudomonas syringae and Escherichia coli. Besides treating and protecting a wide range of plants (including vegetables, fruits, ornamentals, nuts and seeds), the novel technology also serves to nourish and improve their overall health. Compared to commercial Cu-based products, test data indicates that the technology has low cytotoxicity and phytotoxicity, improved rainfastness and increased bioavailability.

Technical Details

The invention is a unique composition of magnesium hydroxide nanoparticles—Mg(OH)₂ NPs—and methods for using the composition to kill plant pathogens effectively. The composition is low in both phytotoxicity and cytotoxicity and does not hamper germination and seedling growth. Designed to degrade into Mg ions, which are nutrients to plant systems, the invention also nourishes and protects plants.

The composition is customizable to each crop to attain optimal efficacy (rainfastness, plant tissue permeability and bioavailability) by controlling the size of the nanoparticles (from a few nanometers to hundreds of nanometers) and by tuning their surface charge (hydrophilicity/hydrophobicity). This is done by coating the particles with water-soluble capping agents made from food-grade chemicals (ligands) such as trisodium citrate, betaine or both, and by adjusting the relative percentage of oppositely charged ligands, such as the ratio of betaine to citrate.

Benefit

Market Application

Publications

Antimicrobial Magnesium Hydroxide Nanoparticles as an Alternative to Cu Biocide for Crop Protection,  Journal of Agricultural and Food Chemistry, 2018 66 (33), 8679-8686 DOI: 10.1021/acs.jafc.8b01727.