Strategies to modulate 1-MCP effects in 'Packham's Triumph' pears: simultaneous application with ethylene or CO 2 and temperature treatments

Two trials were conducted in order to evaluate the effectiveness of several approaches to restore ripening ability of ‘Packham’s Triumph’ pears treated with 1-methylcyclopropene (1-MCP). Results showed that a simultaneous application of 0.3 μL L -1 1-MCP with 0.15 or 0.3 μL L -1 ethylene or with 5% CO 2 allowed the fruit to ripen after 160d of storage. Among these treatments, 0.3 μL L -1 1-MCP with 0.15 μL L -1 ethylene absolutely controlled superficial scald even after 210d of storage. When 0.6 μL L -1 1-MCP were applied, the simultaneous application with 0.6 μL L -1 ethylene or with 5% CO 2 allowed the softening of the fruit only after 230d, and also maintaining a very low incidence of superficial scald. The efficacy of temperature treatments depended on the time that fruit were warmed. A warming of 2 or 3 weeks was needed to restore ripening in fruit treated with 0.6 μL L -1 1-MCP and stored for 230 or 160d, respectively and 2 weeks was also effective in fruits treated with LSD 1-MCP and stored for 210d. However, these temperature treatments developed the highest incidence of superficial scald. In conclusion, the competition for the binding sites by ethylene or CO 2 are the most promissory strategies since they modulate 1-MCP effects maintaining low incidence of superficial scald in ‘Packhams Triumph’ pears.