Susceptibility of Japanese pears to low concentrations of ethylene during storage

The ' Nijisseiki' cultivar of Japanese pears (Pyrus pyrifolia) is also known as nashi in Australia. Nashi were exposed to levels of < 0.005, 0.01, 0.1 and 1.0 mu L/L of ethylene in air during 26 weeks storage at 0 degrees C. Levels of ethylene as low as 0.01 mu L/L increased chlorophyll loss and visual green colour. Increasing ethylene levels also increased softening and internal browning, although flesh spot decay was reduced in the presence of ethylene. While it would be worthwhile to remove ethylene during long- term storage of ' Nijisseiki' in air, another alternative, adding 2% carbon dioxide to the atmosphere, is suggested as a possible low cost means to overcome the ripening effect of ethylene.