Synergism between potassium sorbate dips and brief exposure to high CO2 or O-2 at curing temperature for the control of citrus postharvest green and blue molds

Abstract

Synergistic effects and very effective control of citrus postharvest green and blue molds, caused by Penicillium digitatum and Penicillium italicum, respectively, were observed on artificially inoculated 'Valencia' oranges and 'Clemenules' and 'Ortanique' mandarins after a potassium sorbate (PS) treatment was followed by 2 days of storage in atmospheres of elevated CO2 or O-2 at a curing temperature. A combined treatment consisting of 60-s dips in aqueous solutions of 3% PS heated to 62 degrees C was followed by 48-h exposure to air, 15 kPa CO2 or 30 kPa O-2 at 33 degrees C. Control treatment was a 60-s water dip at 20 degrees C followed by 24-h exposure to air at 20 degrees C. Synergism was observed on citrus fruit either incubated at 20 degrees C for up to 22 days, simulating direct commercialization, or stored at 5 degrees C for up to 45 days, simulating commercial cold storage. This research offers potential new tools to the citrus industry for implementation of nonpolluting integrated postharvest disease management programs, especially devoted to high added value organic markets or export markets with zero residue tolerance. (C) 2015 Elsevier Ltd. All rights reserved.