Browsing by Author "Palou, L"

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    Effects of continuous 0.3 ppm ozone exposure on decay development and physiological responses of peaches and table grapes in cold storage
    (ELSEVIER SCIENCE BV, 2002) Palou, L; Crisosto, CH; Smilanick, JL; Adaskaveg, JE; Zoffoli, JP
    Continuous ozone exposure at 0.3 ppm (v/v) (US-OSHA Threshold Limit Value for short term exposure) inhibited aerial mycelial growth and sporulation on `Elegant Lady' peaches wound inoculated with Mondinia fructicola, Botrytis cinerea, Mucor piriformis, or Penicillium expansum and stored for 4 weeks at 5 degreesC and 90% relative humidity (RH). Aerial growth and sporulation, however, resumed afterward in ambient atmospheres. Ozone exposure did not significantly reduce the incidence and severity of decay caused by these fungi with the exception of brown rot. Gray mold nesting among `Thompson Seedless' table grapes was completely inhibited under 0.3 ppm ozone when fruit were stored for 7 weeks at 5 degreesC. Gray mold incidence, however, was not significantly reduced in spray inoculated fruit. Continuous ozone exposure at 0.3 ppm increased water loss after 5 weeks of storage at 5 degreesC and 90%, RH in `Zee Lady' peaches but not after 4 weeks of storage in `Flame Seedless" grapes. Respiration and ethylene production rates of `O'Henry' peaches were not affected by previous exposure to 0.3 ppm ozone. In every test, no phytotoxic injuries of fruit tissues were observed in ozonated or ambient atmosphere treatments. (C) 2002 Elsevier Science B.V. All rights reserved.
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    Minimum constant sulfur dioxide emission rates to control gray mold of cold-stored table grapes
    (2002) Palou, L; Crisosto, CH; Garner, D; Basinal, LM; Smilanick, JL; Zoffoli, JP
    Sulfur dioxide generating pads, are used worldwide for the control of gray mold, caused by Botrytis cinerea, during long-term cold storage and/or export shipment of table grapes. We propose using an emission rate (measured in mumol SO2 per kilogram of fruit exposed per hour of exposure) to assess the amount of sulfur dioxide that a generating pad should emit during storage/shipment. Inoculated berries were weighed and placed inside gas-tight containers attached to a flow-through fumigation system and continuously exposed to 0.00, 0.25, 0.50, 1.00, 2.00, or 3.00 muL/L sulfur dioxide (inlet concentrations) at 0degreesC for 6 weeks. These low concentrations simulated continuous emission of sulfur dioxide from a hypothetical slow-release generating pad. Grids with spray-inoculated Redglobe berries and open petri dishes with a central syringe-inoculated berry in contact with surrounding healthy berries were used for evaluating gray mold incidence and gray mold nesting, respectively. None of these sulfur dioxide emission rates completely controlled berry decay, while nesting was effectively prevented by sulfur dioxide emission rates of 3.6 and 5.5 mumol/kg hr (inlet concentrations of 2.0 and 3.0 muL/L). Both gray mold incidence and nesting were higher among control fruit at 95 to 98% relative humidity than at 65 to 75%, but no significant differences were observed when an inlet sulfur dioxide concentration of 3.0 muL/L was applied. Sulfur dioxide was continuously sorbed by the grapes during exposure and did not noticeably injure any fruit in these tests.