Effect of gaseous ozone exposure on the development of green and blue molds on cold stored citrus fruit.
Palou, L., Smilanick, J. L., Crisosto, C. H. and Mansour, M.
Plant Disease. Volume 85, Number 6, 2001. Pages 632-638.
2001
บทคัดย่อ
The effects of gaseous ozone exposure on in vitro growth of Penicillium digitatum and P. italicum and development of postharvest green and blue moulds on artificially inoculated citrus fruit were evaluated. Valencia oranges were continuously exposed to 0.3 plus or minus 0.05 ppm (vol/vol) ozone at 5 deg C for 4 weeks. Eureka lemons were exposed to an intermittent day-night ozone cycle (0.3 plus or minus 0.01 ppm ozone only at night) in a commercial cold storage room at 4.5 deg C for 9 weeks. Both oranges and lemons were continuously exposed to 1.0 plus or minus 0.05 ppm ozone at 10 deg C in an export container for 2 weeks. Exposure to ozone did not reduce final incidence of green or blue mould, although incidence of both diseases was delayed about one week and infections developed more slowly under ozone. Sporulation was prevented or reduced by gaseous ozone without noticeable ozone phytotoxicity to the fruit. A synergistic effect between ozone exposure and low temperature was observed for prevention of sporulation. The proliferation of spores of fungicide-resistant strains of these pathogens, which often develop during storage, may be delayed, presumably prolonging the useful life of postharvest fungicides. In vitro radial growth of P. italicum, but not of P. digitatum, during a 5-day incubation period at 20 deg C was significantly reduced by a previous 0.3 plus or minus 0.05 ppm ozone exposure at 5 deg C for 4 days. Inoculum density did not influence the effect of gaseous ozone on decay incidence or severity on oranges exposed to 0.3 plus or minus 0.05 ppm ozone at 20 deg C for one week. Susceptibility of oranges to decay was not affected by a previous continuous exposure to 0.3 plus or minus 0.05 ppm ozone at 20 deg C for one week. A corona discharge ozone generator was effective in abating ethylene in an empty export container.