Plums cv. Blackamber were treated with 250, 500, 750, 1000 nl l(-1) of 1-methylcyclopropene (1-MCP) upon harvest at two ripening stages (S1 and S2) followed by 15, 30, 45 days of cold storage at 0 degrees C and 90% RH and their subsequent 3 days of shelf life at 20 degrees C during the years 2008 and 2009. All doses of 1-MCP retarded the softening of fruits at both ripening stages in both years, suppressed the ethylene production and slowed down titratable acidity losses during shelf life. Hence the storability of 1-MCP-treated plums could be extended up to 2 weeks of cold storage plus 3 days of shelf life at 20 degrees C. 1-MCP treatment was effective on fruits even at late harvest stage (S2), an important aspect for fruits harvested at later stages depending on market demands. Results of the present work revealed that applied doses of 1-MCP were effective in maintaining fruit quality attributes even with late harvested fruits in addition to the extension of shelf life during cold storage at 0 degrees C at 90% RH and subsequent shelf life at 20 degrees C.