Softening and ethylene production of kiwifruit reduced with 1-methylcyclopropene

Kiwifruit soften rapidly in response to exogenous ethylene and susceptibility increases with advancing fruit maturity. Premature softening at 0 degreesC is undesirable and can result in significant economic losses. Strategies are needed to reduce rate of fruit softening during storage. Kiwifruit were exposed to 0, 1, 10 and 100 muL.L-1 1-methylcyclopropene (MCP) for 16 h then maintained at 20 degreesC after harvest or at 0 degreesC for 1 month before transfer to 20 degreesC. MCP reduced ethylene production and softening in fruit maintained at 20 degreesC after harvest, with only minor differences between treatments on fruit from 0 degreesC. The 1 MCP effect tended to be concentration dependent. Fruit were exposed to either 10 muL.L-1 MCP immediately after harvest and treated with 10 muL.L-1 ethylene after different times at 20 degreesC or 0 degreesC, or treated with MCP and ethylene on removal to 20 degreesC after different times at 0 degreesC. When applied at harvest MCP had little effect on C2H4 induced softening after fruit removal from 0 degreesC. However when MCP was applied after fruit removal from 0 degreesC and then challenged with C2H4, softening rate was reduced to a level similar to controls and fruit treated with MCP alone.