BACKGROUND: In some pear varieties like ‘Conference’, 1-methylcyclopropene (1-MCP) treatment often impairs the ripening process indefinitely and the pears remain ‘evergreen’. To better understand this behaviour, the influence of the harvest date, orchard location and year on the effectiveness of 1-MCP treatment was investigated.
RESULTS: Pear softening was inhibited by 1-MCP treatment and the effectiveness of the treatment depended on harvest date, orchard location and year. Differences in the rate of softening in 1-MCP-treated pears depended mainly on the fruit physiological maturity at the moment of 1-MCP treatment. Accordingly, the combination of the Streif index and ethylene production at harvest appeared to be able to predict the evergreen behaviour. Treated pears with a low Streif index (<0.8) and high ethylene production at harvest (≥0.23 µL kg−1 h−1) maintain significantly high firmness but did soften during shelf life, reaching acceptable eating quality.
CONCLUSION: Evergreen behaviour was mainly influenced by the initial fruit maturity and especially by the ability of the fruit to produce ethylene at the moment of treatment. More mature fruit were able to overcome the inhibition by 1-MCP, and the solution to prevent evergreen behaviour therefore lies in the adequate determination of harvest maturity. © 2012 Society of Chemical Industry