Respiration rate was high in young fruit with a rapid decline to 10 DAF followed
by only a slight decrease towards 80 DAF (Fig. 2). Ethylene production was high
in young fruit followed by almost no production up to 70 DAF. Mature fruit
produced much ethylene but showed no increase in respiration and the repeated
experiments conducted in different seasons had the same tendency (data not shown).
Passion fruit has been classified among climacteric fruits which have distinguishing
features of increased respiration and ethylene production rates during ripening
and a response to exogenously applied ethylene (Biale and Young, 1981).