Preparation of green-nano zinc, and study its inhibitory effect on powdery mildew disease under laboratory conditions

Abstract

The present study focuses on the preparation of green-synthesized zinc oxide nanoparticles (ZnO NPs) using Saccharomyces cerevisiae extract and evaluates their inhibitory effect on powdery mildew disease under laboratory conditions. Powdery mildew, caused by Erysiphe necator, is a major fungal pathogen that reduces crop yield, leaf quality, and overall plant vigor. Conventional fungicides are widely used to control this disease; however, their repeated application raises concerns regarding environmental safety, pathogen resistance, and chemical residues in food. Consequently, there is a growing interest in developing eco-friendly alternatives that combine effectiveness with sustainability. Nanotechnology, particularly the use of biologically synthesized nanoparticles, has emerged as a promising approach to plant disease management. In this study, ZnO NPs were synthesized using an eco-friendly biological method and characterized through various techniques, including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-visible spectroscopy. These methods confirmed the morphology and crystalline structure of the nanoparticles. The antifungal activity of three concentrations 50, 100, and 150 ppm was evaluated against powdery mildew leaf spot symptoms to determine their effectiveness in controlling this plant disease. Results demonstrated that ZnO NPs exhibited inhibitory activity at all tested concentrations, with effectiveness increasing proportionally to the dosage. The minimum inhibitory concentration (MIC) was determined to be 50 µg/mL, indicating strong suppression of E. necator. The study provides valuable insights into the potential application of nanotechnology in plant protection and supports the development of sustainable agricultural practices.