Issue link: http://read.dmtmag.com/i/54939
Dealing with carbon dioxide sensitivity Strategies are available to help cold storage operators avoid carbon dioxide injuries. by Melissa Hansen In carbon dioxide- sensitive apple varieties, like these Golden Delicious, fruit harvested early tends to have peel injuries. Internal breakdown occurred in this Golden Delicious apple, as a result of carbon dioxide injury. A ll apples release carbon dioxide as part of the fruit respiration process. But some varieties, like Golden Delicious and Empire, are more sensitive to carbon dioxide and require special postharvest management strategies. However, cold-storage operators have several options available to avoid peel and internal injuries associated with carbon dioxide injury. Dr. Jim Mattheis specializes in postharvest physiology of apples, pears, and cherries with the U.S. Department of Agriculture in Wenatchee, Washington. He has developed strategies to help cold- storage operators better manage carbon dioxide injury that can occur in Golden Delicious, Empire, Jonagold, Fuji, Braeburn, and Honeycrisp. Carbon dioxide injury shows up as browning and cavities in the peel, flesh, and core. Injury tends to differ from other storage disorders, Mattheis said, in that it usually occurs during the first four months of storage. Mattheis believes that with the widespread use of MCP or SmartFresh (methylcyclopropene), the car- bon dioxide sensitivity for some varieties that used to be more sporadic is now more consistent and needs to be managed on a routine basis. "There's no way to know if a lot of fruit will be sensitive or not, so we now have to manage for the risk of sensitivity being there," he said. "But we have tools to make it possible to manage risk." The process of fruit respiration produces energy (which drives the continued life of the fruit), carbon dioxide, water, and heat, Mattheis explained. "The challenge is in managing the negative aspects of carbon dioxide and 26 FEBRUARY 15, 2012 GOOD FRUIT GROWER www.goodfruit.com courtesy jim mattheis