Ethylene production and fruit quality traits To determine if JA application had an influence on the onset and progression of ripening, ethylene and fruit quality evolution were analysed. In control fruit, ethylene production was first detectable 119 dAFB (17 d after treatment), peaked at 123 dAFB (harvest), and then declined sharply (130 dAFB, second harvest; Fig. 2A). The lower MJ concentration tested (0.22 mM) did not significantly affect ethylene production and fruit quality traits at any application time (data not shown). In contrast, early treatments with 0.44 mM MJ and 0.20 mM PDJ led to fruit with dramatically inhibited (by ;90%) ethylene production at harvest (i.e. 21 d after application; Fig. 2A); 7 d later, ethylene emission in treated fruit increased by
2–4-fold relative to the previous harvest. Similarly, midperiod application of MJ (0.44 mM) and PDJ inhibited whole fruit ethylene production at harvest (14 d after application) relative to controls, though to a lesser extent than after the early application (;60%; Fig. 2D).