1-Methylcyclopropene: a review

Since the discovery of 1-methylcyclopropene (1-MCP) as an inhibitor of ethylene action, over 100 studies have examined details of its action, application and effects on ethylene inhibition. This plant growth regulator is a tool that can help scientists make major advances in understanding the role of ethylene in plants. 1-MCP prevents ethylene effects in a broad range of fruits, vegetables and floriculture crops. Effective concentrations are low and range from 2.5 nl l−1 to 1 μl l−1. Concentration interacts with temperature such that low concentrations of 1-MCP applied over longer durations may be as effective as high concentrations. 1-MCP is most commonly applied at 68–77 °F (20–25 °C), but can be used at lower temperatures in some commodities. Generally, treatment durations of 12–24 h were sufficient to achieve a full response. A variety of factors may need to be considered when using 1-MCP including cultivar, developmental stage, time from harvest to treatment, and multiple applications. Depending on the species being treated, 1-MCP may have a variety of effects on respiration, ethylene production, volatile production, chlorophyll degradation and other color changes, protein and membrane changes, softening, disorders and diseases, acidity and sugars. This review compiles what is known about the technological uses for 1-MCP, defines where discrepancies exist between reports, and aims to define areas requiring further study.