본 실험은 고온기 근권냉방이 파프리카의 배지온도 하강과 파프리카의 생리적 반응에 미치는 영향을 알아보고자 7월 16일부터 10월 15일까지 코이어 배지에서 재배 하였다. 냉방방식은 공기순환 덕트(지름 12cm, 미세구멍 (0.1mm)으로 찬 공기(7월~8월; 20 ± 2oC, 9월; 23 ± 2oC) 를 야간시간(오후 5시~오전 3시) 공급하였다. 고온기(7월 23일부터 8월 31일) 중 파프리카 배지의 일평균 온도가 냉방처리구는 24.7oC, 대조구는 28.2oC로, 냉방처리구에서 대조구보다 3.0~5.6oC 배지온도가 낮아 졌다. 하루 중 맑은 날(650~700W · m−2) 주간(오전 5시~ 오후 8시)/야간(오후8시~오전5시) 냉방처리구 배지 온도는 대조구보다 1.7oC/3.3oC 낮아졌다. 오후 6시에서 8시까지 초저녁 배지온도 하강속도가 냉방처리구에서는 평균 0.5oC/h, 대조구는 0oC/h였다. 배지 상부와 하부 간의 대조구 대비 냉방처리구의 온도차도 각각 1.3oC, 0.6oC 였다. 냉방처리는 고온(28~32oC) 배지 온도 노출율을 대조구 대비 32.5% 감소시켰다. 냉방처리구의 파프리카 광합성, 증산율 및 수분포텐셜은 대조구보다 높았다. 첫 개화시기도 대조구보다 4일 앞당겨지고, 착과수도 증가하였다. 냉방처리구의 엽장은 짧아졌으나, 초장, 경경, 분지수, 엽폭 등은 차이가 없었다. 야간 근권냉방으로 배지 온도가 3.0~5.6oC를 낮추었으나, 고온기 온실 온도가 고온에서는 파프리카 착과가 지연되므로, 지상부 온도 하강 방법을 병행하면 파프리카 생육과 착과에 효과적이라 판단된다.

This study examined a technique for cooling root zone aimed at lowering substrate temperature for sweet pepper (Capsicum annum L. ‘Orange glory’) cultivation in coir substrate hydroponics during hot season, from the 16th of July to 15th of October in 2012. The root zone cooling technique was applied by using an air duct (∅12 cm, hole size 0.1 mm) to blow cool air between two slabs during night (5p.m. to 3a.m.). Between the 23rd of July and 31st of August (hot temperature period), average daily substrate temperature was 24.7oC under the root zone cooling, whereas it was 28.2oC under condition of no cooling (control). In sunny day (600~700 W m−2 · s−1), average substrate temperatures during the day (6a.m. to 8p.m.) and night (8p.m. to 6a.m.) were lower about 1.7oC and 3.3oC, respectively, under the cooling treatment, compared to that of control. The degree of temperature reduction in the substrate was averagely 0.5oC per hour under the cooling treatment during 6p.m. to 8p.m.; however, there was no decrease in the temperature under the control. The temperature difference between the cooling and control treatments was 1.3oC and 0.6oC in the upper and lower part of the slab, respectively. During the hot temperature period, about 32.5% reduction in the substrate temperature was observed under the cooling treatment, compared to the control. Photosynthesis, transpiration rate, and leaf water potential of plants grown under the cooling treatment were significantly higher than those under the control. The first flowering date in the cooling was faster about 4 days than in the control. Also, the number of fruits was significantly higher than that in the control. No differences in plant height, stem thickness, number of internode, and leaf width were found between the plants grown under the cooling and control, except for the leaf length with a shorter length under the cooling treatment. However, root zone cooling influenced negligibly on eliminating delay in fruiting caused by excessively higher air temperature (> 28oC), although the substrate temperature was reduced by 3oC to 5.6oC. These results suggest that the technique of lowering substrate temperature by using air-duct blow needs to be incorporated into the lowering growing temperature system for growth and fruit set of health paprika.

Abstract.
 서 론
 재료 및 방법
 결과 및 고찰
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 Literature Cited

• 최기영(서울시립대학교 환경원예학과, Department of Environmental Horticulture, The University of Seoul) | Ki Young Choi
• 고지연(서울시립대학교 환경원예학과, Department of Environmental Horticulture, The University of Seoul) | Ji Yeon Ko
• 최은영(건국대학교 녹색기술융합학과, Department of Green Technology Convergence, KonKuk University) | Eun Young Choi
• 이한철(국립원예특작과학원 시설원예시험장, Protected Horticulture Experiment Station, NHRI, RDA) | Han Cheol Rhee
• 이성은(제주한라대학교 마축자원학과, Department of Equine Resource, Cheju Halla University, Jeju, Jeju Special Self-Governing Province) | Sung Eun Lee
• 이용범(서울시립대학교 환경원예학과, Department of Environmental Horticulture, The University of Seoul) | Yong-Beom Lee Corresponding author