• Journal of Ginseng Research
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• 제41권3호
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• pp.370-372
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• 2017

Three greenhouse experiments with American ginseng seedlings growing under light levels from 4.8% to 68% showed a quadratic response for root dry weight, giving an optimal root dry weight of 239 mg (range 160-415 mg) at an optimal light level of 35.6% (range 30.6-43.2%).

• 한국농공학회논문집
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• 제59권6호
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• pp.81-87
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• 2017

The total area of domestic reclaimed lands is 54,379 ha, and among these, 30,394 ha can be agriculturally available. To increase an agricultural availability of reclaimed land, controlled horticultural products that can be highly profitable have come to the fore. However, as being characteristically concerning, when original glasshouse is intactly applied in reclaimed land, it is unsafe on account of ground subsidence and, even if ground were reinforced, it has a problem by high cost. So a new greenhouse model would be necessary taking into account not only cost-efficiency but also safety with relatively light-weight one. Before this, this paper estimated acceptance rate of controlled horticultural complexes in reclaimed land and new greenhouse model for 414 farmers. The annual rental fee is 129,712,500 won/ha, considering the interest rate (2.5 %) of the investment, the depreciation cost of the facilities (straight line depreciation method, 20 years of service life estimated), and government subsidy rate (50 %) which resulted in a sufficient number of intended tenants with the acceptance rate of 0.33. The results of this paper may contribute to the government's policies for reclaimed land.

• Journal of Ginseng Research
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• 제39권4호
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• pp.345-353
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• 2015

Background: Ginseng is a semishade perennial plant cultivated in sloping, sun-shaded areas in Korea. Recently, owing to air-environmental stress and various fungal diseases, greenhouse cultivation has been suggested as an alternative. However, the optimal light transmission rate (LTR) in the greenhouse has not been established. Methods: The effect of LTR on photosynthesis rate, growth, and ginsenoside content of ginseng was examined by growing ginseng at the greenhouse under 6%, 9%, 13%, and 17% of LTR. Results: The light-saturated net photosynthesis rate ($A_{sat}$) and stomatal conductance ($g_{s}$) of ginseng increased until the LTR reached 17% in the early stage of growth, whereas they dropped sharply owing to excessive leaf chlorosis at 17% LTR during the hottest summer period in August. Overall, 6-17% of LTR had no effect on the aerial part of plant length or diameter, whereas 17% and 13% of LRT induced the largest leaf area and the highest root weight, respectively. The total ginsenoside content of the ginseng leaves increased as the LTR increased, and the overall content of protopanaxatriol line ginsenosides was higher than that of protopanaxadiol line ginsenosides. The ginsenoside content of the ginseng roots also increased as the LTR increased, and the total ginsenoside content of ginseng grown at 17% LTR increased by 49.7% and 68.3% more than the ginseng grown at 6% LTR in August and final harvest, respectively. Conclusion: These results indicate that 13-17% of LTR should be recommended for greenhouse cultivation of ginseng.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 동계 학술대회 논문집
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• pp.196-201
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• 2000

• 한국환경농학회지
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• 제42권1호
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• pp.14-20
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• 2023

Light is an important factor that influences the growth and development of flowering plants. The present study investigated the effects of in vitro acclimatization to different light colors (white light (WL; control), blue light (BL; 447 nm), green light (GL; 519 nm), and red light (RL; 667 nm)) on the growth of petunia (Petunia hybrida) and of hardening cultivation of plant transferred form in vitro to a greenhouse under sunlight. Compared to the control, the shoot length and leaf width of Petunia increased by 42% and 11.7%, respectively, after acclimatization to BL and the shoot growth increased by 29.3% after acclimatization to RL. The chlorophyll and carotenoid contents after acclimatization to BL and GL were 16.7% and 11.3% higher, respectively, and 14.4% and 11.9% higher, respectively, than those in the control. During greenhouse cultivation, the shoot length increased by 16.7% and 11.3%, respectively, after acclimatization to BL and RL, respectively, and the leaf length and leaf width increased by 14.4% and 11.9%, respectively, after acclimatization to GL. While dry weight of root of GL and BL was not significant difference in vitro, increased by 59.0% and 22.9% ex vitro than that of WL. Thus, acclimatization to BL increased the shoot growth and leaf chlorophyll contents, and acclimatization to GL and RL enhanced shoot and root growth, in petunia.

• Elastomers and Composites
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• 제55권2호
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• pp.114-119
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• 2020

The effect of a greenhouse-covering material on its indoor environment and on the characteristics of cherry tomatoes grown in it was investigated. The conventional polyethylene (PE) film on the greenhouse roof was replaced by a polycarbonate (PC) sheet, while maintaining the main structural frame intact. Color changes and the formation of water droplets on the PC surface were avoided by applying coextrusion and coating layers. When compared to the PE greenhouse, the PC greenhouse enabled increased light transmittance and thus a higher indoor temperature during both summer and winter. The thermal insulating property of the PC sheet effectively reduced the heating loss by approximately 55% during winter. The cherry tomatoes grown in the PC greenhouse exhibited superior fruit characteristics in terms of size, weight, and sugar content. The total amount of cherry tomatoes produced per unit area (1,000 ㎡) in the PC greenhouse was found to be greater by approximately 19% compared to that in the PE greenhouse.

• 생물환경조절학회지
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• 제6권2호
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• pp.86-91
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• 1997

분지각을 기준으로 유인방법을 달리한 시설 고추 재배에서 군락내 수광태세와 초고별 기관분포로 살펴본 군락생산 구조 분석과 생육 및 수량을 조사하여 생육 전반적인 군락생산 구조는 흡광계수, 군락 모식도 측면에서 45$^{\circ}$ 처리후 직립구에서 가장 좋았다. 초장은 직립구에서 가장 컸으며 1차분지 이후의 평균 절간장은 45$^{\circ}$ 처리구가 가장 짧았으나 경경, 엽면적, 식물체 무게는 45$^{\circ}$ 처리후 직립구에서 가장 우수하게 나타났다. 수량은 45$^{\circ}$ 처리후 직립구>45$^{\circ}$ 처리구>직립구 순이었으나, 수확 과수는 45$^{\circ}$ 처리후 직립구>직립구>45$^{\circ}$ 처리구 순이었다.

• 생물환경조절학회지
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• 제4권2호
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• pp.232-239
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• 1995

This study was carried out to get required torque data needed to design and develop a roll-up ventilation system in a pipe-constructed plastic film green-house. The results obtained from this study are as follows : 1. The required torques of a roll-up ventilation system in greenhouse are the functions of its length. The torques should multiplied by the conversion coefficients (2.0 in ceiling vent, 1.8 in side vent) in case of application. 2. In constructing pipe-constructed plastic film greenhouse, a shaft pipe is the largest essential element in roll - up shaft weight constitution which have an effect on the required torques. Therefore, the pipe should be light using nonferrous materials like aluminum alloy. 3. A planetary reduction ventilator of differential ring gear type is suitable for a roll-up ventilation system, because it can make high efficient reduction just using the first step shift.

• 생물환경조절학회지
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• 제4권2호
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• pp.167-174
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• 1995

This study was carried out to find a way of improving the windproof capability of greenhouse foundations. Generally, greenhouses are often collapsed due to the strong winds, because they are very light weight structures. In such a critical situations, the foundations are very often subjected to uplift and vibration at the same time. This paper describes both the wind disaster of greenhouses by the typhoon FAEY and the uplift resistance of greenhouse foundations. Followings are the results obtained from this study ; Judging from the view point of year round cultural aspects, it is recommended that some measures be taken for the preventions of greenhouse film ruptures because greenhouse structural damages are found to be directly associated with the local rupture of cover film. In the case of surveyed area, movable pipe-houses or pipe-houses of 1-2W type were found to be completely destroyed when the maximum instantaneous wind velocity was over 30m/sec or so. In the case of movable pipe-houses, the uplift resistance of greenhouse was expected to increase with the increase of pipe diameter and/or the embedment pipe length. But at present situations there is a limitation in raising the uplift resistance of movable pipe-house, because pipe diameters as well as pipe lengths customarily selected by farmers are quite a much limited.

• 생물환경조절학회지
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• 제5권1호
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• pp.23-33
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• 1996

시설하우스에 이용되는 시설자재의 규격화와 품질개선을 유도하기 위하여 피복자재의 종류별, 두께별로 물리적 기계적 특성을 시험 분석하였다. 피복재의 물리적 기계적 특성은 충격강도, 인장 인열강도 및 파장별 투과율을 측정하였으며, 시험한 결과를 요약하면 다음과 같다. 1. 다트식 낙추시험에서 연질필름의 충격 강도는 피복재가 두꺼울수록 파괴하중이 증가하여 50% 파괴수준의 하중이 158-213g 범위에 있었으며, LDPE 필름이 대체로 높게 나타났다. 2. 충격파괴정도를 보면 전혀 파괴되지 않는 최대 충격하중이 62-192g 범위였으며, 0.05mm에 비해 0.1mm 두께의 필름이 충격에 견디는 힘이 1.8-3.2배 더 강한 것으로 나타났다. 3. 인장하중은 0.95-2.22kg 범위로 피복재 길이 방향이 높고, LDPE 필름이 높게 나타났으며, 신장율은 345-1020% 범위로 길이보다 폭방향이 1.4-2.7배 더 신장되는 것으로 나타났다. 4. 인열강도는 80.S-121.7kg/cm의 범위로 LDPE 필름이 높고 EVA가 낮은 것으로 나타났으며, 길이방향보다 폭방향이 더 큰 값으로 나타났다. 5. 연질필름의 종류별 광투과특성은 자외선 영역에서 87-92%로 큰 차이가 나타나지 않았으나 가시광선 영역에서 높은 투광율을 나타내었다.