Ripening stage affects the chilling sensitivity of greenhouse-grown peppers

Greenhouse-grown 'Bison' and 'Doria' peppers (Capsicum annuum L.) were harvested when mature green (MG) ( 95% surface green) or ripe ( 95% of surface red or yellow). Both cultivars responded similarly to temperature and neither exhibited chilling injury (CI), as indicated by surface pitting, after storage at 13C for 1 or 2 weeks. Ripe peppers showed no CI when held at 1 C for 1 or 2 weeks, while MG peppers exhibited CI after these treatments. Exposing MG peppers to 1C for 3 days caused CI and stimulated C2H4 (12.3x) and CO2 production (2.5x). In contrast, a similar exposure of ripe peppers did not cause CI but stimulated C2H4 (6.5x) and CO2 production (1.4x). It seems that CO2 and C2H4 production was stimulated by exposure to 1C, not necessarily by CI development. Our data question the physiological significance of elevated CO2 and C2H2 production in CI development. The observed tolerance of ripe peppers to 1C suggests that ripe greenhouse-grown peppers can he stored at temperatures lower than those currently recommended for bell peppers