REDUCING CHILLING INJURY BY SHORT-TERM COLD ACCLIMATION OF CUCUMBER SEEDLINGS UNDER PROTECTED CULTIVATION

Plants were exposed to a stepwise treatment regime starting from 25°C to 12°C for two or three days or transferred directly from 25°C to a 6°C chilling treatment as a control.
Control plants had greater electrolyte leakage than acclimated plants.
Both treatments (12°C for either two or three days) resulted in approximately the same decrease in electrolyte leakage, and reduced chilling injury effects.
The acclimated plants also had higher chlorophyll contents than non-hardened control plants.
Post-stress observations showed that control plants were in general taller than treated plants, hardened plants flowered five days earlier, and yielded more than untreated chilled control plants.
These results indicate that low temperature hardening treatments tend to increase subsequent tolerance to chilling stress.