Foliar application of zinc oxide nanoparticles improves rice yield under biotic stress posed by Magnaporthe oryzae

Rice blast disease, caused by the fungus Magnaporthe oryzae, poses a significant threat to rice production worldwide. A pot experiment was conducted to test the hypothesis that foliar-applied zinc oxide nanoparticles (ZnONPs) have an inhibitory effect against blast fungus by strengthening the antioxidant defence system in rice plants. Various treatment concentrations of ZnONPs (10, 20, 30, and 40 mg/L) were applied to pathogen-inoculated plants. Foliarly applied ZnONPs lowered the infection efficiency of the sprayed conidia by 73% on the leaf segments compared to the positive control. The lesion number caused by the pathogen in the leaf tissues was significantly reduced compared to the experiment's positive control, and the sporulation intensity was reduced compared to the positive control. Foliar-applied ZnONPs improved the functions of superoxide dismutase, phenylalanine ammonia-lyase, peroxidase, and catalase enzymes. Furthermore, the growth and yield attributes of rice plants were improved compared to the positive control. Yield and production of rice can be improved with exogenously applied ZnONPs under the rice blast infestation.