The threshold value for physiological action of ethylene on apple fruits

Abstract
Summary: In fruit picked at various stages of development and stored at 12°C, the threshold concentration of applied ethylene required to cause an increase in respiration decreased as the fruit matured. In young fruits 10 days elapsed between the application of 10 ppm ethylene (for the first 3 days) and an increase in respiration. By contrast, in mature fruit, close to the respiration climacteric, as little as 0°1 to 1 ppm ethylene induced an increase in respiration within a few days. Relatively massive production of ethylene and the development, in discs of peel taken from the fruit, of a malate effect (excess CO2 produced on addition of malate) occur some time after increase in respiration. The implications of these results in the control of the respiration climacteric are discussed.