Destruction of Rhizopus stolonifer and Botrytis cinerea by ozone/ions treatments

The fungicidal activity of the combined treatment ozone/ions was investigated on the development of Rhizopus stolonifer and Botrytis cinerea. R. stolonifer and B. cinerea, two common postharvest pathogens of strawberries, were inoculated on gelose and exposed to 10(6) ions/cm(3) of air with ozone concentrations of 0.05, 0.1, 0.5 or 1 ppm. Strawberries were wounded and inoculated with R. stolonifer or B. cinerea and exposed to the same ozone/ions concentrations for 12, 24, 48 and 72 hours. The results showed a significant fungicidal and/or fungistatic effect of the combined ozonefions treatments on the fungus. In vitro treatments showed that, after 36 hours of exposure to ozone concentrations of 0.05 and 0.1 ppm, the cell count decrease for R. stoloniferwas 57 and 76% respectively, while it was 68 and 78% for B. cinerea. Exposure to ozone concentrations of 0.5 and 1 ppm over the same period of time resulted in 99 and 98% decrease for R. stolonifer and B. cinerea, respectively. Ozonefions treatment in wounded strawberries allowed 91.1 and 98.8% reduction of the counts after 72 hours of exposure to 1 ppm of ozone respectively for R. stolonifer and B. cinerea.