Effects of 1-methylcyclopropene alone and in combination with polyethylene bags on the postharvest life of mango fruit

Experiments were conducted to determine how 1-methylcyclopropene (1-MCP) treatments influence ethylene-stimulated ripening of harvested mango cv. Zihua fruit at 20 degreesC. The ripening response of fungicide (prochloraz) treated fruit was characterised following various I-MCP treatments in sealed jars followed by storage in polyethylene bags and/or subsequent ethephon (ethylene) exposure. Exposure of fruit to increasing concentrations of 1-MCP for 12 h resulted in the reduced softening of produce when subsequently held in air for 7 days after ethephon treatment. Application levels of between 1 and 100 mul litre(-1) 1-MCP had increasing impact, while 200 mul litre(-1) 1-MCP apparently began to approach response saturation. Exposure of fruit to 50 or 100 mul litre(-1) concentrations of 1-MCP for periods from 1 to 24 h subsequently resulted in reduced softening of produce when held in air for 7 days after ethephon treatment. Increasing periods of exposure from 1 to 12 h had increasing impact, while exposure times greater that 12 h appeared to reach saturation. In the absence of ethephon-stimulation, the natural ripening of mangoes held in polyethylene bags was delayed by prior exposure to 100 V1 litre-1 1-MCP for 12 h. Extended holding of 1-MCP treated and non-1-MCP treated control fruit in polyethyene bags encouraged physiological and pathological deterioration. Following exposure to 100 il litre-1 1-MCP for 12 h, mango fruit held for 10 days in polyethylene bags showed a delay in the onset of ripening relative to bagged but non-2-MCP treated control fruit. Treatment with 1-MCP allowed storage of mango fruit in plastic bags at 20 degreesC for 30 days. Observations suggest that 1-MCP treatments do not adversely influence the quality of the post-storage ethephon-ripened fruit. Thus, application of 1-MCP in combination with the use of polyethylene bags can extend the postharvest life of mango fruit at ambient temperature. Treatments that extend postharvest life are important in developing countries, such as China, where the cold chain infrastructure is often lacking.