Rose flower ( Rosa hybrida L. ) from Rosaceae family, one of the most popular species of rose family, is usually considered as a cut flower, potted or emphatic plant. Their life span depends on how they are cultivated, harvested, and preserved. Gray mold from pathogenic fungi, ( Botrytis cinerea Pers ) is one of the most widespread diseases of the rose family. Treatment using plasma exposure has the potential to destroy a wide range of microorganisms including spores, bacteria, and viruses. Therefore, plasma on the basis of dielectric barrier discharge (DBD) is effective to disinfection of the surfaces, that is non-thermal and appropriate for materials sensitive to heat. In the first phase of the present experiment, a setup was designed using high voltage source made by Shahid Behesti university. To eradicate gray mold and evaluating the quality of the petals, leakage of ions, relative water content, proline accumulation, dominant pigments of petals and color shift was determined. Gray mold was treated using 10, 11, and 12 kV for 6, 7, and 8 minutes of plusma exposure. Results indicated that gray mold vanished completely using 11 kV for 8 minutes, and 12 kV for 7 to 8 minutes of plasma exposure. Using plasma at 11 kV for 8 minutes proved to minimum difference between the physiological properties of petals and control samples. In the second phase, Enhancedtech-18A unit made by Kavosh Yaran Fan Poya Company was used using 10, 15, and 20 kV, for 4, 6, and 8 minutes, the power of 50 kW, and the frequency of 20 kHZ. It was found that gray mold was completely destroyed using 20 kV for 4, 6, and 8 minutes. Gray mold vanished 70% using 15 kV for 8 minutes of plusma exposure and 90% using 10 kV for 8 minutes. No significant difference was observed between means of chi-squares of the physiological properties of rose petals using 15 kV for 6 minutes, and 20 kV for 4 minutes, compared with control samples. Gray mold was also exposed to corona discharge using 10, 15, and 20 kV at the frequency of 50 HZ. Results indicated that corona discharge was able to remove the fungi gray mold using 20 kV for 20 minutes, however, a serious damage was observed on rose petals. Therefore, it can be say plasma exposure using dielectric barrier discharge was suitable to eliminate gray mold of rose petal without changing in the physiological characteristics. Keywords: Rose flower, gray mold, cold plasma, dielectric barrier discharge, leakage of ions, proline, color shift
