doi:10.1038/nindia.2017.123 Published online 21 September 2017
When copper and chitosan, a polymer found in crab shell, come together in a nanocomposite, they shield maize crops from a fungal disease, thus boosting yield and facilitating sustainable agriculture1.
Widespread use of synthetic agrochemicals contaminates the environment, breeds chemical-resistant microorganisms and disrupts soil ecosystems. In search of an eco-friendly way to fight crop diseases, scientists from the Maharana Pratap University of Agriculture and Technology in Rajasthan, Chaudhary Charan Singh Haryana Agricultural University and Washington University in St. Louis, United States, synthesized the nanocomposite by mixing chitosan with copper.
The fungal disease depletes antioxidants and defence enzymes in maize, increasing the levels of reactive oxygen species that destroy plant cells. Treating disease-afflicted maize plants with the nanocomposite increased the levels of antioxidant and defence enzymes such as superoxide dismutase and peroxidase.
The enzymes broke down the reactive oxygen species, converting them into harmless water and oxygen. This, in turn, protected the plants against disease-induced stress and damage.
Disease and poor soil cause micronutrient deficiencies in crops such as maize. The nanocomposite slowly released essential copper, compensating the micronutrient deficiency in maize. It also notably increased plant height, stem diameter, root length and number and chlorophyll content.
The ability to sustain plant growth makes the nanocomposite suitable for commercial use in agriculture, the researchers say.
1. Choudhary, R. C. et al. Cu-chitosan nanoparticle boosts defense responses and plant growth in maize (Zea mays L.) Sci. Rep. 7:9754 (2017)