Abstract
This study was conducted to investigate the cooling efficiency and growth of tomatoes by root zone cooling device using a pad-box and cultivated system. The structure of the root zone cooling system using a pad-box was four piece of pads bonded an the side and a fan set at the bottom. Cool wind was generated by the outside air which was punched at intervals of 10 cm along three rows. Cold wind flowed to the root zone in the culture medium. The root zone cooling efficiency of cold wind generation by using a pad-box flowing through a wet-pad was determined. Major characteristic of this cuttural system consist of bed filled with a perlite medium and a ventilation pipe using PVC. The cold wind generation by a pad box (CWP) was compared to that of cold wind generation by a radiator (CWR), cold water circulation using a XL-pipe (CWX) and the control (non-cooling). When the temperature of water supplied was 16.2-18.4$^{\circ}C$, temperatures in the medium were 20.5~23.2$^{\circ}C$ for CWP 22.7~24.2$^{\circ}C$ for CWR, 22.8~24.27$^{\circ}C$ for CWX and 23.1~-29.6$^{\circ}C$ for the control. The results show that the cold wind temperature using the pad-box was lower by 1~2$^{\circ}C$ than that of cold water circulation in the XL-pipe and lower by 5~6$^{\circ}C$ than that of the control. Growth such as leaf length, leaf width, fresh weight and dry weight, was greater in three root zone cooling methods than in the control. Root activity was higher in the rat zone cooling methods than in the control. However, there was no significant difference among root zone cooling methods.
근권냉방 방식에 따른 냉방 효율과 토마토 생육 특성을 검토하고자 XL냉수순환, 라디에이타 냉풍, 패드냉풍 및 대조구를 처리한 결과는 다음과 같다. 근권부 냉방온도는 공급수온이 17.8$^{\circ}C$일 때 XL 냉수순환구는 18.$0^{\circ}C$ 라디에이타 냉풍구는 27.2$^{\circ}C$, 패드 냉풍구는 20.3$^{\circ}C$였다. 배지 깊이와 시간대별 평균온도는 XL냉수순환구 22.8~24.7$^{\circ}C$. 라디에이타 냉풍구 22.7~24.2$^{\circ}C$, 패드 냉풍구 20.5~23.2$^{\circ}C$, 대조구 25.9~29.6$^{\circ}C$를 나타내어 냉방처리구가 대조구에 비해 5~6$^{\circ}C$더 낮았다. 토마토의 생육에 있어 엽장. 엽폭은 대조구에 비해 컸으며, 생체중 및 건물중의 경우에서도 비슷한 경향이었다 근활력에 있어 대조구는 45.0ug/g에 비해 근권냉방 처리구는 58.5-62.8 ug/g으로 높았으나. 근권냉방 처리구간에는 큰 차이가 없었다.