Changes in Ripening Behaviors of 1-MCP-Treated 'd'Anjou' Pears After Storage

1-Methylcyclopropene (1-MCP), an ethylene action inhibitor, was applied to 'd'Anjou' pears (Pyrus communis L.) at 20 degrees C between 2 and 5 days after harvest. Scald of 'd'Anjou' pears was completely controlled by 1-MCP at a concentration between 0.05 and 0.3 mu l l(-1) after a prolonged cold storage plus 7 days of exposure to an environment with or without 500 mu l l(-1) ethylene at a temperature of 20 degrees C or 25 degrees C. 1-MCP inhibited the biosyntheses of a-farnesene and its oxidative products (conjugated trienes) and thus controlled scald. However, fruit treated with the above concentrations of 1-MCP did not ripen normally in an environment with or without ethylene. Ethylene production and fruit softening of 1-MCP-treated 'd'Anjou' pears were inhibited during 7 and 15 days at 20 degrees C. 'd'Anjou' fruit treated with 0.01 and 0.02 mu l l(-1) 1-MCP ripened normally on day 7 at 20 degrees C after 3 months of cold storage at -1 degrees C, and ripened fruit did not develop any incidence of scald. Untreated fruit developed substantial scald. After 4 months of storage or longer, both untreated fruit and fruit treated with 0.01 and 0.02 mu l l(-1) 1-MCP developed an unacceptable incidence of scald upon ripening. Thus, use of other scald control methods may be necessary in addition to treatment with a low dosage of 1-MCP to insure both normal ripening and scald control for d'Anjou pear fruit from the Mid-Columbia district. (C) 2005 by The Haworth Press, Inc. All rights reserved.