Effect of High-Carbon Dioxide and Low-Oxygen Controlled Atmospheres on Postharvest Decays of Apples. J. W. Sitton, Department of Horticulture and Landscape Architecture, Washington State University, Pullman 99164-6414. M. E. Patterson, Department of Horticulture and Landscape Architecture, Washington State University, Pullman 99164-6414. Plant Dis. 76:992-995. Accepted for publication 4 May 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0992.

Controlled atmosphere storage with carbon dioxide concentrations above 2.8% reduced the development of lesions incited by Botrytis cinerea (causing gray mold), Penicillium expansum (causing blue mold), and Pezicula malicorticis (causing bull’s-eye rot) in McIntosh, Delicious, and Golden Delicious apples (Malus domestica) kept for 61 days at 0 C. Low-oxygen atmospheres were less effective for decay control. Older apples stored in air for 8 mo at 0 C prior to the CO₂ treatment had a higher incidence of brown skin discoloration (scald) when exposed to CO₂ concentrations above 8% than younger fruit stored in air at 0 C for 7 wk before receiving controlled atmosphere treatments. Apple firmness, soluble solids, and titratable acidity were not adversely affected by the high-CO₂ or low-O₂ atmosphere treatments.