Abstract:

Frost has had a prominent influence on the fruit industry in China in recent years. We need to establish a system to simulate frost treatment for fruit trees. Based on observations of frost events in field, we analyzed the characteristics of frost in terms of cooling rate, the low temperature limit, warming rate, and light conditions after frost treatment and established a system to simulate frost treatment in the laboratory. Temperature during the frost treatment in field could be divided into three stages: cooling, extreme temperature maintenance and warming. The temperature during cooling and warming stages changed in an approximately linear manner. Frost is generally followed by high intensity light. The simulated frost process was determined as followed: the temperature drops from room temperature (20°C) to 5°C in 30 min, and is maintained at 5°C for 30 min, then decreases to -2°C at a rate of 0.8°C·h ^-1, is maintained at -2°C for 2 h, then increases to 5°C at a rate of 4.7°C·h ^-1 in the dark. The recovery condition after frost was 16°C and 800 μmol·m ^-2·s ^-1.

Key words: frost, temperature, light, simulation