Gray mold disease caused by Botrytis cinerea is one of the serious factors that reduce storage period and marketing life of tomato. The decrease of post-harvest wastage of tomato by environmentally friendly fungicides would be of great significance to farmers and consumers. Accordingly, using of antifungal activities of various metal nanoparticles can be suitable method for the management of postharvest disease. In this study, the extract of Rosmarinus officinalis was applied to green synthesis of copper nanoparticles by fast preparation method. Characterizations of green copper nanoparticles were tested by UV–Vis absorption spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and dynamic light scattering (DLS). The size of copper nanoparticles were at about 100-300 nm. We examined the in vitro antifungal activity of green copper nanoparticles against B.cinerea with different concentrations and the strong inhibitory rate was observed in 15 mmol/l green copper nanoparticles at five day after inoculation. Also, the fruits quality of tomato at 10 days after artificially inoculated by B.cinerea and maintained at 24 °C were improved with increasing copper nanoparticles concentrations. According to our results, the green copper nanoparticles can be a good alternative to decrease the tomato fruits rots in comparison chemical fungicides.
