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 1C 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 C 2 H 4 (12.3x) and CO 2 production (2.5x). In contrast, a similar exposure of ripe peppers did not cause CI but stimulated C 2 H 4 (6.5x) and CO 2 production (1.4x). It seems that CO 2 and C 2 H 4 production was stimulated by exposure to 1C, not necessarily by CI development. Our data question the physiological significance of elevated CO 2 and C 2 H 4 production in CI development. The observed tolerance of ripe peppers to 1C suggests that ripe greenhouse-grown peppers can be stored at temperatures lower than those currently recommended for bell peppers.