From Laboratory to Field: The Effect of Controlling Oscillations in Temperature on the Growth of Crops

Abstract

Crops are grown in natural conditions. Environmental factors such as temperature, humidity, and light irradiance have a regular pattern. A grower chamber is usually used to test the effect of environmental factors on the crops. If crops were cultivated under fixed environmental conditions, the results would be different from that for plants that are grown in a natural environment. Limits in the capability of an apparatus mean that most studies use a fixed temperature, a fixed relative humidity, or a fixed light intensity. In an accumulated temperature study, Pak choi and strawberry were used to compare the difference between fixed and oscillating temperature conditions in a growth chamber. There were three temperature patterns: the high-temperature (HVT) oscillation pattern (day: 22–32 °C; night: 19–25 °C), low-temperature (LVT) oscillation pattern (day: 21–29 °C; night: 19–23 °C), and the fixed temperature (CT) regime (day: 25 °C; night: 22 °C). The light intensity was 80 μmol∙m−2s−1. The environments used for the Pak choi experiments were the HVT oscillation pattern, the CT pattern, and the inside air temperature for a net house. The strawberries had three treatments: the HVT and LVT oscillation patterns, and the CT pattern. The fresh weight of total plants, the leaf area, the leaf number, and the chlorophyll content were measured for the two crops. For strawberries, the fresh weight of the leaves and the Brix value were measured. The experimental results show that there is a significant difference in the growth characteristics for these three regimes. The results of the growth characteristics of Pak choi and strawberry for an oscillating temperature are better than those for a fixed temperature environment with a statistically significant difference. For the biological and agricultural experiments, an oscillating temperature in the growth chamber realistically simulates a natural environment.