Antimicrobial magnesium hydroxide nanoparticles safely and effectively protect tomatoes and other crops against disease and soil contamination
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. Plant diseases make up 10-16 percent of global harvest loss, thus affecting food crop productivity and quality. Though Cu-based biocides have proven to be effective, the United States Environmental Protection Agency has recognized that prolonged use of such chemicals increases the risk of developing Cu-resistant microbes and accumulating toxic Cu levels in soil.
As an alternative to using CU-based biocides to fight plant diseases, the UCF team created a novel composition that uses magnesium hydroxide nanoparticles. The new composition effectively inhibits and kills 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.
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. An alternative to Cu-based bactericides and fungicides, 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). Customization is achieved 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.
- Cost-effective, environmentally-friendly alternative to prolonged use of Copper (Cu) biocides
- Acts as a nutrient while protecting plants from bacteria and fungi
- Low phytotoxicity and cytotoxicity
- Customizable and suitable for organic crops
- Copper-alternative bactericide/fungicide
- Plant health booster