1-MCP efficacy in extending storage life of 'Bartlett' pears is affected by harvest maturity, production elevation, and holding temperature during treatment delay

The efficacy of 1-methylcyclopropene (1-MCP) in extending storage life of the Pacific Northwest 'Bartlett' pear is inconsistent. The effects of harvest maturity [H1: flesh firmness (FF)approximate to 83.6 N; H2: FF approximate to 74.8N], production elevation (El approximate to 150 m; E2 approximate to 610 m), and holding temperature (0 and 5 degrees C) prior to application of 1-MCP have been measured with respect to ethylene production, fruit quality, and storage disorders of 'Bartlett' fruit during 6 months of storage at -1.1 degrees C. 1-MCP at 0.3 mu LL-1 for 24 h at 0 degrees C inhibited ethylene production, FF and green color losses, senescence disorders, and friction discoloration for H1 fruit from both elevations. However, 1-MCP efficacy was reduced moderately in E1H2 fruit and reduced to a greater extend in E2H2 fruit. Internal ethylene concentration (IEC) at harvest was not detected in H1 fruit from either elevation, but it accumulated in E1H2 and E2H2 fruit (E2H2 > E1H2). The holding temperature at 5 degrees C but not 0 degrees C for 12 d between harvest and 1-MCP treatment increased fruit IEC and ethylene production rate and reduced the fruit response to subsequent 1-MCP treatment. The fruit physiological stage at the moment of 1-MCP treatment determined the efficacy of 1-MCP in extending the storage life of 'Bartlett' pears. 1-MCP retarded development of ripening capacity and 10-14 d at 20 degrees C were needed to ripen 1-MCP treated 'Bartlett' pears to optimum eating quality following 5-6 months of cold storage. (C) 2015 Elsevier B.V. All rights reserved.