• 생물환경조절학회지
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• 제18권4호
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• pp.354-362
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• 2009

본 연구는 장미 순환식 수경재배 시 재배시기별로 적합한 배양액을 개발하고자 일본야채다업시험장 표준액을 1/4S, 1/2S, 2/3S, 1S로 하여 펄라이트와 입상 암면을 4:6 부피비로 섞은 고형배지를 이용하여 실험을 실시하였다. 고온기재배의 경우 1/2S 처리구에서, 저온기의 경우 2/3S 처리구에서 광합성 속도, 절화 품질 및 생육이 우수하였다. 이를 토대로 1/2S(고온기), 2/3S(저온기) 처리구의 양수분 흡수율을 기준으로 새로운 배양액을 조성하였다. 이온의 조성은 고온기의 경우 $NO_{3^-}N$ 6.8, $NH_{4^-}N$ 0.7, $PO_{4^-}P$ 2.0, K 3.8, Ca 3.0, Mg 1.2, $SO_{4^-}S$ $1.2me{\cdot}L^{-1}$, 저온기의 경우 $NO_{3^-}N$ 6.8, $NH_{4^-}N$ 0.7, $PO_{4^-}P$ 2.0, K 3.8, Ca 3.0, Mg 1.2, $SO_{4^-}S$ $1.2me{\cdot}L^{-1}$ 이었다. 개발한 배양액의 적합성 평가실험 결과 UOS 배양액은 Ca, P 등의 이온이 장미의 양분흡수율보다 많이 함유된 기존의 배양액과 비교하여 근권 내 EC 변화가 안정적이었다. 또한 절화수량이 재배기간에 관계없이 기존 배양액보다 높은 결과를 나타내었고 특히 저온기 재배시 아이찌현 배양액 처리구에 비하여 수확량이 140% 증가하였다. 따라서 고형배지를 이용한 장미 순환식 수경재배시 새로 개발된 배양액을 사용할 경우 기존 배양액에 비해 비료절감의 효과와 함께 안정적인 생육 및 수량증대를 기대할 수 있다.

• 생물환경조절학회지
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• 제32권3호
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• pp.249-255
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• 2023

참외는 동북아시아 지역에서 대부분 재배되고 있고, 한국에서 주로 생산되는 과일로서 단위면적당 수확량은 지속적으로 향상되고 있지만 재배방식은 토경재배에 국한되어 있기 때문에 규모화, 생력화를 위한 수경재배 기술 개발이 필요하다. 본 연구에서는 보온부직포를 이용한 수경재배로 참외를 재배할때 영양생장기 배양액 내 질산태질소 비율에 따른 참외 생육의 변화를 확인했다. 배양액에서 질산태질소 비율이 증가할수록 초장은 길어지고, 엽장, 엽폭, 절간장도 함께 증가하였다. 생육 30일차의 SPAD값은 질산태질소 비율이 증가할수록 감소하였다. 질산태질소 비율에 낮을수록 암꽃 개화가 빨리 되었고, 과실 성숙에서는 처리 간 차이가 없었다. 질산태질소 비율에 따른 과실의 형태는 차이가 없었고, 경도는 질산태질소의 비율이 낮을수록 높아 과실이 단단하였다. 3월에서 7월까지 총 수확량은 KM3 5,650kg/10a, KM1 4,439kg/10a로 KM3가 27% 높았고 특히, 참외 가격이 높은 3월에서 5월까지 수량은 KM3가 KM1보다 36% 높았다. 따라서 12월 정식되어 봄철부터 생산되는 참외의 수경재배에 적합한 질산태질소는 6.5-10me·L^-1 수준으로 공급하는 것이 적당할 것으로 판단되었다.

• 생물환경조절학회지
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• 제2권2호
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• pp.126-135
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• 1993

Recently, the characteristic of plant production systems in Korea has been changed with the strong trends of integration and large scale, using environmental control techniques. To satisfy this change successfully, first of all, the environmental prediction inside the system must be preceded. While many environmental prediction models for plant production system were developed by many persons, each model cannot be applied to the every situation without the perfect understanding of source codes and the technical modification. The purpose of this study is building the environmental prediction model to predict and evaluate the environment inside the system numerically, and also developing the multipurpose program available for practical design. The model consisted of the basic system model, the cultivation related model and the environmental control related model. The contents of each model are as follows : the basic system model is dealing with thermal and light environments, soil environment and ventilation : the cultivation related model with soil and hydroponic cultures ; and the environmental control related model with thermal curtain and heat exchanging system. The environmental prediction model was developed using a common simulation program, PCSMP, so that it could be easily understood and modified by anyone. Finally, the model was executed and verified through comparison between simulated and measured results for soil culture, and both results showed good agreements.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1997년도 동계 학술대회 논문집
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• pp.255-262
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• 1997

A low-cost and precise metering device, which is suitable to automatic mixing of nutrient-solution for hydroponic culture, was developed for small-scale growers. The metering device was composed of three parts those were supply pumps, metering cylinders and venturi tube. Those parts were controlled by personal computer with time-based odoff control method. To verify the performance of the developed metering device, the relationship between operating time and discharge was examined and the accuracy of the developed metering device was compared with commercial metering pumps. The results of this study are as follows. 1. The correlation coefficient between the flow rate and operating time was 0.9999, and the linear regression equation computed was y=21.759x, where y is the discharge(g) and x is the operating time(s). 2. The developed device has greater accuracy than commercial metering pumps in terms of the full-scale error. Calculated errors for the developed metering device and two commercial pump were $\pm$0.3 %, $\pm$2.45 % and $\pm$1.38 % respectively. 3. Above results show developed metering device is a useful tool for nutrient-solution control system.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2005년도 추계 학술발표회
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• pp.15-20
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• 2005

Locations of silicon accumulation in rice leaves and its possible association with resistance to rice blast were investigated by analytical electron microscopy and atomic force microscopy. A blast-susceptible cultivar, Jinmi, and partially resistant cultivars, Hwaseong and Suwon345, were grown under a hydroponic culture system with modified Yoshida's nutrient solution. Electron-dense silicon layers were frequently found beneath the cuticle in epidermal cell walls of silicon-treated plants. Increasing levels of silicon were detected in the outer regions of epidermal cell walls. Silicon was present mainly in epidermal cell walls, middle lamella, and Intercellular spaces within subepidermal tissues. Furthermore, silicon was prevalent throughout the leaf surface with relatively small deposition on stomatal guard cells in silicon-treated plants. Force-distance curve measurements revealed relative hardness and smaller adhesion force in silicon-treated plants (18.65 uN) than control plants (28.39 uN). Moreover, force modulation microscopy showed higher mean height values of elastic Images In silicon-treated plants(1.26 V) than in control plants (0.44 V), implying the increased leaf hardness by silicon treatment. These results strongly suggest that silicon-induced cell wall fortification of rice leaves may be closely associated with enhanced host resistance to blast.

• The Plant Pathology Journal
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• 제18권3호
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• pp.142-146
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• 2002

The effect of potassium phosphonate ($KH_2PO_3 or $K_2 HPO_3$) on the control of Phytophthora root rot of lettuce was evaluated in a liquid hydroponic culture. Phosphonate 100 ppm strongly inhibited mycelial growth of Phytophthora species in vitro but did not affect normal growth of lettuce in a greenhouse test. Application of the chemical before infection showed over 94% control value, while it was less than 35% when applied after infection. In a field trial, phosphonate 100 ppm, which was directly supplemented into the nutrient solution, satisfactorily controlled the disease as it did not develop until 28 days after transplanting and remained at less than 2% infection rate at the end of cultivation. Meanwhile, in the control plot, the disease initiated at 7 days after transplanting and developed rapidly reaching over 70% infection rate at 28 days. Population density of the causal pathogen, R drechsleri, in a heavily infested farm was 22.0-25.0 cfu/100 ml of nutrient solution. However, it decreased to 1.3-2.0 cfu/100 ml at 7 days after treatment with phosphonate 200 ppm.

• Journal of Plant Biotechnology
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• 제7권3호
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• pp.195-202
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• 2005

The effects of constituent amino acids of glutathione (GSH), glutamate (Glu), cysteine (Cys) and glycine (Gly), on GSH synthesis in lettuce seedlings were examined in this study. The GSH concentration of the seedlings was increased to 5.1-fold and 1.6-fold the concentration of the control in the first leaves and roots, respectively, by simultaneous application of these constituent amino acids (Glu+Cys+Gly) at 100 mg/l to the culture solution for two days. In the first leaves and roots of these seedlings, the concentration of GSH was 180.4 and 14.6 nmole/gFW, and non-essential amino acids including Glu, Cys and Gly occupied 93.2% and 84.0% of the total free amino acids, respectively. Application of Cys greatly increased the concentration of GSH in the roots, and application of 50 mg/l Cys increased it to 26.1-fold the concentration in the control. The activity of GSH synthetase was higher in the leaves than in the roots, whereas the activity of ${\gamma}$-glutamylcysteine synthetase was higher in the roots than in the leaves.

• 생물환경조절학회지
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• 제3권1호
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• pp.52-57
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• 1994

방울토마토의 수경재배시 과실의 외형형질을 비파괴적으로 추정하고, 이를 검정하였다. ‘Chelseamini’와 ‘뽀뽀’에 비해 ‘Minicarol’의 외형상의 크기(과장, 과폭, 과중, 과실부피)가 특히 작았다. 토마토 과실의 외형형질 간에는 고도의 상관이 인정되어 과실의 생장은 길이생장과 부피생장과 균형있게 이루어지는 것으로 나타났다. 과실의 체적 및 무게는 다음 식으로 추정 가능하였다. 과실의 체적=0.071$\times$(과장+과폭)$^3$＋0.451, 과실의 무게 =0.072$\times$(과장+과폭)$^3$＋0.542. 1993-1994년에 수확한 과실도 이 식으로 설명되었다.

• 한국작물학회지
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• 제45권5호
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• pp.288-293
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• 2000

Two rice cultivars (Oryza sativa L.), Hwa-seongbyeo of Japonica type and Taebackbyeo of Indica/Japonica type, were cultivated with hydroponic culture to examine nitrogen effects on the growth responses, contents and utilizations of carbohydrates, and the ripening velocity of grains with three different N levels. Plant height and tiller number were clearly increased to 80 ppm N level compared to 40 ppm N level and then they were slightly decreased in N level of 120 ppm. Higher dry weights were appeared with 80 ppm N level than did with other N levels, showing statistically differences in both cultivars and N levels, while dry weight of roots was heavier with decreasing the N levels. Therefore, T/R ratios were not significantly different among N levels, although there was statistically differences between rice cultivars. After the flowering stage, higher water-soluble carbohydrate (WSC) and water-insoluble carbohydrate (WISC) were contained in stem compared with other parts, showing that WISC of sheath and stem, unlike WSC, was significantly different among N levels. Starch of grain, WISC, was remarkedly increased from 3.0% at just after the flowering to 52.0% and 75.0% at 15 and 30 day after the flowering, respectively, showing that lower N application had faster accumulation of starch in rice grains. N would affect the contents of carbohydrates of each tissue, and starch accumulation in rice grains.

• Journal of Biosystems Engineering
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• 제35권6호
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• pp.450-457
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• 2010

Although cherry tomato is one of major vegetables consumed in fresh vegetable market, the quality grading method is mostly dependant on size measurement using drum shape sorting machines. Using Visible/Near-infrared spectroscopy, apparatus to be able to acquire transmittance spectrum data was made and used to estimate firmness, sugar content, and acidity of cherry tomatoes grown at hydroponic and soil culture. Partial least square (PLS) models were performed to predict firmness, sugar content, and acidity for the acquired transmittance spectra. To enhance accuracy of the PLS models, several preprocessing methods were carried out, such as normalization, multiplicative scatter correction (MSC), standard normal variate (SNV), and derivatives, etc. The coefficient of determination ($R^2_p$) and standard error of prediction (SEP) for the prediction of firmness, sugar, and acidity of cherry tomatoes from green to red ripening stages were 0.859 and 1.899 kgf, with a preprocessing of normalization, 0.790 and $0.434^{\circ}Brix$ with a preprocessing of the 1st derivative of Savitzky Golay, and 0.518 and 0.229% with a preprocessing normalization, respectively.