Studies on the Physiology of Tomato Fruits. II. Ethylene Production at 20° C as Related to Respiration, Ripening, and Date of Harvest

Abstract

The pattern of ethylene produc-tion by ripening tomato fruits (Lycopersicon esculentum) was established in relation to respiration and the rate of ripening. The general shape of the ethylene evolution pattern was found to be that of a sigmoid curve. Production of ethylene in measurable quantities began with the 1st appearance of color and at about the onset of the climacteric rise in respiration. A definite relationship between the maximum rates of ethylene evolution and of carbon dioxide production was not observed. Many fruits show a peak of ethylene production, but tomatoes appear to produce the most ethylene near the end of the storage life. The total amount of ethylene produced by tomatoes during ripening is very small compared to other fruits, and their ethylene/carbon dioxide ratio is consequently one of the lowest. No consistent seasonal changes in the pattern or magnitude of ethylene production were observed; hence, it appears that the failure of mature-green tomatoes to ripen properly late in the season is not related to their loss of ability to produce ethylene.