The increase in temperature due to climate warming is predicted to affect crop yields in the future. Until now, various types of OTC (open top chamber) that simulate the future climate condition have been developed and used to study the effect of temperature increase due to global warming on maize growth. However, in most OTCs, high equipment and maintenance costs were required to artificially increase the temperature. This study was carried to develop a cost-effective and simple OTC suitable for climate warming experiments for forage maize. Three octagonal OTCs with a height of 3.5 m × a diameter of 4.08 m and a partially covered top were constructed. The lower part of OTC covered film was opened at a height of 26 cm (OTC-26), 12 cm (OTC-12) from the ground surface, or not opened (0 cm, OTC-0). Mean air temperatures during the daytime on a sunny day in OTC-0, OTC-12 and OTC-26 increased to 3.23℃, 1.33℃, and 0.89℃, respectively, compared to the ambient control plot. For a pilot test, forage maize, ‘Gwangpyeongok’ was grown at OTCs and ambient control plots. As a result, in the late maize vegetative growth phase (July 30), the plant height was increased more than 45% higher than the ambient control plot in all OTC plots, and the stem diameter also increased in all OTC plots. These results indicate that it is possible to set the temperature inside the OTC by adjusting the opening height of the lower end of the OTC, and it can be applied to study the response of forage maize to elevated temperature. An OTC, with its advantages of energy free, low maintenance cost, and simple temperature setting, will be helpful in studying maize growth responsiveness to climate warming in the future.

ABSTRACT
Ⅰ. INTRODUCTION
Ⅱ. MATERIALS AND METHODS
    1. Open top chamber and experimental design
    2. Climatic data measurement
    3. Cultivation of forage maize
    4. Statistical analysis
Ⅲ. RESULTS AND DISCUSSION
    1. Changes in temperature and humidity in OTC
    2. Forage maize growth in OTC at different temperatures
Ⅳ. CONCLUSION
Ⅵ. REFERENCES

• Byung-Hyun Lee(Division of Applied Life Science (BK21) and Institute of Agriculture & Life Science (IALS), Gyeongsang National University) Corresponding author
• Jeong Sung Jung(Grassland and Forage Division, National Institute of Animal Science, RDA)
• Il-Kyu Yoon(Division of Applied Life Science (BK21) and Institute of Agriculture & Life Science (IALS), Gyeongsang National University)
• Min-Jun Kim(Division of Applied Life Science (BK21) and Institute of Agriculture & Life Science (IALS), Gyeongsang National University)
• Inam Khan(Division of Applied Life Science (BK21) and Institute of Agriculture & Life Science (IALS), Gyeongsang National University)
• Chang-Woo Min(Division of Applied Life Science (BK21) and Institute of Agriculture & Life Science (IALS), Gyeongsang National University)