• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.157-164
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• 2023

Codonopsis lanceolata (S. et Z.) Trautv. is mainly cultivated in Korea and China as a medicinal crop. C. lanceolata is difficult to produce plug seedlings in the summer, because C. lanceolata has a low germination rate and is vulnerable to high temperatures. Cold treatment is effective in breaking dormancy of seeds and increasing the germination rate. Shading cultivation can control the solar irradiance received by plants and reduce the damage by high temperatures and strong light. This study was conducted to examine the appropriate cold treatment period for the improving germination of C. lanceolata, and shading level during the summer seedling period. Cold treatment experiments were conducted for 0 (control), 1, 2, 3, and 4 weeks at 4℃ before sowing. In the shading experiment, C. lanceolata was grown for 45 days with 0 (non-treatment), 45, 75% shading levels. Cold treatment for one week significantly improved the germination energy. The plant height, leaf area, and fresh and dry weights of C. lanceolata seedlings were significantly increased under the 45% shading level. Total root length, root surface area, and the number of root tips were significantly higher in shading treatment (45 and 75%) than in non-treatment. The C. lanceolata seedling's compactness and Dickson's quality index were the highest at 45% shading level. Therefore, these results recommended sowing C. lanceolata after cold treatment for one week at 4℃, and 45% shading level could stably culture C. lanceolata plug seedlings during the high temperature period.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.393-401
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• 2017

The nitrate ($NO_3{^-}$) accumulation of hydroponically grown leafy vegetables may increase in the condition of a closed-type plant production system with low light intensity due to low activity of enzymes involved in nitrogen assimilation and the use of $NO_3-N$ as major nitrogen source. The objective of this study is to investigate the effects of light intensities, nutrient solution compositions and the time of nutrient solution removal before harvest on nitrate contents of hydroponically-grown lettuces in a closed plant production system. The reduction of nitrate contents in leafy lettuces 'Cheongchima' was higher in the treatments of 'TW' (nutrient solution removal) and '$(NH_4)_2CO_3$' (use of ammonium carbonate as nitrogen source) than those in other treatments, which significantly lowered fresh weight and leaf area of the plants. In the light intensity of $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, the nitrate content was effectively reduced without causing any growth retardation, by substitution of the nutrient solution composition that $NO_3-N$ was removed ('$NO_3-N$ removal' treatment) or the half strength of standard nutrient solution was applied ('1/2 S' treatment), for 7days before harvest. The effects of light intensity and the time of nutrient solution removal before harvest on growth and nitrate contents in leafy lettuces were investigated. The nitrate contents in leaves under the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ before nutrient solution removal were lower than those of 100 or $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. The removal of nutrient solution for 7 days before harvest quickly reduced the amount of nitrates in leaves in all the light intensities with a greater degree under the $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light condition, while the 7 days-removal with both 200 and $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light conditions caused decrease in 16~31% of leaf area and 20~35% of fresh weight, compared to the 3 days-removal treatment. The nitrate contents were greatly reduced from 3,018 to 1,035 in $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and 2,021 to 480 ppm in the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, with the nutrient solution removal for 3 days before harvest, without causing any deterioration in growth and product quality. The vitamin C contents in leaves were higher in the treatment of nutrient solution removal for both 3 and 5 days before harvest with the light condition of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ than those in the light condition of 100 or $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$.

• Journal of Korean Society of Forest Science
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• v.83 no.1
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• pp.32-37
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• 1994

Artificial acid rain(pH 3.0, 4.0 and 5.0) and ground water(pH 6.5) were treated on the potted seedlings of Pinus rigida and Pinus koraiensis to examine its effects on the contact angles on needle surface. Artificial acid rain was prepared by diluting sulfuric acid with ground water and ground water(pH 6.5) was used as control. Artificial acid rain was sprayed to the pots two times per week for growing season, one time per week for winter seasons. About 5mm of artificial acid rain was treated each time from late April, 1992 to early October, 1993. Contact angles on the needle surface were measured and compared among the treatments. The results were summarized as follows. Contact angles between needle surface and water droplet decreased with decrease of pH values of artificial acid rain. Measuring and comparing contact angles might be very effective criteria for early diagnosis of acid rain injury in the field.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.401-406
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• 2002

식물조직 배양공정의 기계화 기술개발을 위한 기초자료를 얻고자 식물조직 배양기술의 개발 또는 식물묘를 대량생산하는 연구지도기관 및 농원 등의 배양실 10개소를 대상으로 배지의 분주, 배양용기의 밀봉 및 세척, 배양체의 접종공정 등에 대한 작업실태를 조사분석한 결과를 요약하면 다음과 같다. 가. 배양기술의 개발 또는 식물묘 대량생산은 대부분이 나리, 호접란, 풍란, 심비디움 등 화훼류였으며, 배지는 모두 한천이 혼합된 고체배지, 배양용기는 형상 및 용량 등이 다른 플라스크, 배양병, pE용기 등이 사용되었다. 나. 배지의 분주작업은 조사대상 10개배양실중 6개소는 작업자가 비이커를 사용하여 분주하였고 4개소는 자동 또는 반자동분주기를 사용하였으며, 인력 및 반자동분주기의 사용시 배양용기간의 분주량은 기준량의 $\pm$25%범위에서 차이가 있었다. 다. 액체배지의 분주시 온도는 36.8~88.$0^{\circ}C$, 점도는 3.7~11.8cP 범위였고 점도는 배지에 혼합하는 한천, 사과 등 유기물의 량에 따라 차이가 있으므로 배지의 분주작업을 기계화하기 위해서는 배지의 온도와 점도, 배양용기와 분주량 등을 종합적으로 고려하여 배지의 점도에 따라 분주량을 조절할 수 있도록 개발할 필요성이 있다고 생각된다. 라. 배양용기의 밀봉소재는 플라스크의 경우 호일 또는 고무마개와 호일, 배양병은 모두 나사산이 있는 캡, PE용기는 뚜껑을 사용하였으며, 밀봉작업은 모든 배양실에서 인력에 의존하였고 작업능률은 호일만으로 밀봉하는 경우 시간당 180~240병, 캡은 시간당470~600개 정도였다. 마. 배양체의 접종작업은 모든 배양실이 인력에 의존하였으며, 배양체를 배지와 분리하여 불필요한 부분을 제거하고 배양작물에 따라 생육정도를 2~3등급으로 구분하여 배양용기의 배지 위에 치상하는 과정으로 수행되었으며, 작업능률은 호접란의 경우 배양병에 25본을 접종하는데 시간당 6병, 심비디움은 원형 플라스크에 25본을 접종하는데 시간당 10병 정도였다. 바. 식물체의 대량증식에 사용되는 플라스크, 배양병, PE용기 등 배양용기의 세척작업은 농원의 1개배양실에서 간이식 세척기, 이 외의 9개배양실은 모두 물에 담겨 두었다가 세제와 브러쉬 등을 사용하여 인력으로 세척하고 있어 생력화 기술개발이 요구되었다.

• Applied Biological Chemistry
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• v.26 no.2
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• pp.132-136
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• 1983

The indole-3-acetic acid(IAA) oxidase activity of shoot and root tips of etiolated pea seedlings (Pisum sativum L. var. Sparkle) during and after chilling was determined. The IAA oxidase level of root tips was 4 to 15 times as high as that of shoot tips. During chilling the seedlings apical and subapical 5 mm shoot sections increased in IAA oxidase activity but apical and subapical 5 mm root sections decreased. When chilled plants were returned to $25^{\circ}C$ to recover, the enzyme activity had a tendency to restore to the activity level of controlled plants.

• Journal of Sericultural and Entomological Science
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• v.35 no.1
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• pp.7-10
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• 1993

Mulberry grafting season in normally a one month period starting at the end of March. Such a short period creates a shortage of qualified grafters and inflates wages. Pine tree sawdust was tested as a medium in which to preserve graftages. Sawdust was moistened to two ratios of water to dry weight of sawdust (1.5 and 2.0). Scions were either grafted the same day they were collected or first incubated for 10days at 15$^{\circ}C$. Grafting period could be extended to the middle of February under 1.5 times moisture content and fresh scions. Preservation of scions increased water content, T-N, P2O5, CaO and inositol, whereas decreased total C, glucose and fructose. With no preservation total C decreased, inositol increased slightly early March followed sharp decrease, and sucrose increased with time.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.232-239
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• 2016

The objective of this study was to examine the effect of photoperiod and light intensity of RBW LED (red:blue:white = 2:1:1) on the growth of Taraxacum coreanum Nakai in a fully artificial light type plant factory. 3 photoperiods and 4 light intensity were used respectively in a fully artificial light type plant production system. Plants were cultured with three photoperiods and four light intensity regimes (conditions) for 270 and 120 days, respectively, using nutrient film technique (NFT) or aeroponics culture methods. For each photoperiod, the total leaves per plant harvested 8 times in all cultivation period was 224 in the 16/8(day/light) photoperiod that had no significant difference from 220 in the 12/12 photoperiod and the lowest number of leaves was 151 occurred in the 8/16 photoperiod, which means that the longer photoperiod, the more leaves harvest. Total fresh weight of above ground was the high in order of in 16/8 photoperiod as 125g, 12/12 photoperiod as 91g, 8/16 photoperiod as 56g. For each light intensity, the total leaves per plant harvested 4 times in all cultivation period was the great in order of $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 123, $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 107, $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 95, $50{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 56 which was the smallest number of total leaves harvest. Total fresh weight of above ground per plant was the high in order of $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 43.6g, $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 34.6g, $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 32.2g, $50{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as 18.2g. From these results, it was concluded that photoperiod of 16/8 and light intensity at $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ can be used as the light condition of RBW LED (red:blue:white = 2:1:1) for optimal growth of Taraxacum coreanum Nakai in a fully artificial light type plant factory.

• Korean Journal of Organic Agriculture
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• v.22 no.1
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• pp.197-208
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• 2014

The present study was conducted to provide basic data for efficient vermicomposting of swine manure by investigating the effect of sawdust mix on growth and reproduction of earthworms, amount of earthworm cast produced, and its chemical composition when mixing swine manure in different levels (0(SSD0), 10(SSD10), 20(SSD20), 30(SSD30), and 40%(SSD40)) with sawdust commonly used as moist control in manure composting. The C/N ratio of the feed and the survival rate of earthworms for the SSD0 treatment (10.19, 35.2%), The C/N ratio of the feed was 11.09-16.44 and increased with higher level of sawdust mixed, and the survival rate of earthworms during the experiment period was 35.2-100%. The number of earthworms was 16.6 in the SSD40 treatment, and young worms were not found in the SSD0 treatment or the treatment with less than 30% sawdust in the mix. The number and the weight of cocoons in SSD30 and SSD40 treatments were found to be in the ranges of 23.8-59.8 and 256-660 mg respectively. The production of earthworm cast and digested amount were higher with the higher level of mixed sawdust (p<0.05), and the C/N ratio of cast increased with the mixed sawdust ratio, being significantly higher ratio in SSD30 and SSD40 than other treatments (p<0.05). Heavy metals content tended to decrease with the mixed sawdust level. To summarize, the higher level of mixed sawdust was associated with improvement in growth and reproduction of earthworms, and 30-40% sawdust mix in particular could result in efficient vermicomposting.

• Journal of Agricultural Extension & Community Development
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• v.7 no.1
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• pp.181-191
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• 2000

This experiment was conducted to find out the effects of mushroom cultivation on ozone susceptibility. The mushroom media in cultivation became softening well without bad Knell when it was soaked for 120 hours. The mushroom media softening on cultivating of oyster mushroom was good and fast when the concentration of gas condition ozone is high. The concentration of gas condition ozone must control at less than 0.02 ppm at the innoculation room, 0.03 ppm at the incubating room, must not use at the sprouting mom, less than 0.02 ppm at the growing room respectively. Also at the growing room, it removes the smell of mushroom, so has a protective effects of coming into mushroom fees and disease. When the concentration of 0.02 ppm liquid condition ozone was sprinkled, it was very useful in disease protection If it was input, the storage period of mushroom fruiting body was prolonged.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.409-414
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• 2010

The first drainage time in a day was controlled for precise irrigation management with low consumption of nutrient solution in tomato perlite bag culture system by measuring water level of drained water in drainage catchment part. This method automatically adjusted the irrigation time under any condition of light, temperature and humidity, resulting in stable water content in substrates. However, it was difficult to keep the time consistent as they were set. It drained with the deviation of 20 min in the treatment in which the first drainage time was set at 10:00 and 50 min in the treatment set at 10:30. The first drainage time was not constant, but the drain occurred stably before noon in the treatment of which irrigation frequency was longer than 30 min. The drainage ratio was better balanced in all the treatments using drainage level sensors than the treatment using time clock for irrigation control. High water and fertilizer efficiencies were obtained. Although the growth, total yield and sugar content were not significantly different between the treatments, fruit weight was higher in the treatments using drainage level sensors than that using timer.