Response to ethylene and its interactive effects with N6-benzyladenine (BA) in harvested green olives during ripening

Abstract

Abstract The ability of ethylene to affect postharvest ripening in developing green ‘Konservolia’ olives was investigated after exposure of harvested fruit to ethylene concentrations up to 1000 μl l −1 at 12 and 25 °C. The interaction of ethylene at 1000 μl l −1 with N 6 -benzyladenine (BA) at 75 mg l −1 on ripening was also investigated in late developing green (mature) olives. The high temperature accelerated the ripening processes. Skin green colour loss and fruit firmness decreases were advanced by exposure time at each temperature. Ethylene production rates were low after the ethylene treatments and not affected by them. In early harvested fruit, at both temperatures, ethylene had no effect on changes in respiration rates after the ethylene treatment and on firmness decreases, but promoted the skin green colour loss slightly with concentrations equal to or higher than 10 μl l −1 after 10 days treatment. In late developing fruit, ethylene and/or BA at 12 °C had no effect on respiration, skin colour changes and firmness decreases. In these olives, controls and ethylene-treated fruit at 25 °C, and all olives at 12 °C, retained much of their green colour. However, ethylene at 25 °C in mature-green fruit inhibited the promotive effect of BA on red–purple skin coloration, and in the presence or absence of BA resulted in higher respiration rates after the treatment and in lower firmness decreases than in non-treated fruit.