• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.276-280
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• 2012

This study was conducted to determine the ideal beginning date of plastic house optimum heating for off-season (December) production of asparagus. To achieve this, the 1.6-year-old 'Green tower' asparagus was cultivated in Jeju area ($33^{\circ}$28.110N, $126^{\circ}$31.076E) and the yield and quality among 7 different beginning dates of heating from Oct. 25 to Jan. 20 with 15-days interval were compared. The heating was controlled to maintain the inside temperature was higher than $20^{\circ}C$, But the plastic house was ventilated when the inside temperature rose to $30^{\circ}C$. Days to sprouting took longer as heating dates were delayed. Days to sprouting took 52 days in heating at December 30, and the days were shortened thereafter. As the beginning of heating was delayed, sprouting of asparagus was retarded. Among treatments, days to sprouting was 52 days and longest when the heating began on December 30. When the heating began on October 25, harvest was earliest and started on 7 November. When the heating began on November 15 and 30, harvest started on November 30 and December 18, respectively. Harvesting started on November 7 for October 25 heating, November 30 for Nov. 15 heating, and December 18 for November 30 heating, respectively. When the heating began was done after December. 15, harvesting was possible after early January. The number of spear, spear weight and yield were highly increased in the treatments of heating after January. 10 when the asparagus dormancy was broken. In the case of heating dates were before the asparagus dormancy breaking, the total yield was highest in November 15 heating with 607 kg/10a. The marketable yield of November 15 heating was 386kg/10a, which was twice higher than the 193 kg/10a of October 25 heating. Accordingly, it is recommended to start heating on November 15 for the production of off-season (December) asparagus in Jeju. Therefore, the optimum heating date to start was November 15 for the improvement of quality and yield of off-season (December) asparagus in Jeju area.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.408-412
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• 2013

This study was carried out to investigate damp injury caused by tomato coir bag culture and prevent that. The tomato variety was used 'Minichal', and tomatoes were grown in greenhouse. The nutrient solution based on Yamazaki Tomato Standard Solution was irrigated from one hour after sunrise to two hour before sunset. The slits for darainage were made in three types; I, L, and bottom slit type. The coir bag of I and L type had six slits of 15cm length, that of bottom slit type had three slits of 15 cm length. The weight of coir bag in 24 hours after saturation was 14.2 kg in I type, 13.8 kg in L type, and 12.8 kg in bottom slit type, but there was not significant difference. The weight of coir bag after one day irrigation was 14.5 kg, 14.2 kg, and 13.3 kg at L, I, and bottm slit type, respectively. This means that the moisture content of coir bag during cultivation was lowest in bottom slit type. The number of adventitious root on stem was 160, 170, and 53 at I, L, and bottom slit type, respectively. The dry weight of root and root length were highest at bottom slit type, compared to other treatment. The marketable yield was highest 26.5 kg/20 plant in bottom slit type. For increasing yield and preventing damp injury, bottom slit type was most effective at U type bed coir bag culture.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.250-256
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• 2006

This experiment was conducted to investigate the hydroponic culture possibility and the optimal solution strength of 'Pechika' ever-bearing strawberry in summer highland. Maximum room temperature and minimum root zone temperature of plastic house were $30.8^{\circ}C\;and\;19^{\circ}C$ in highland respectively and $4^{\circ}C\;and\;3^{\circ}C$ lower than in level and. The growth of 'Pechika' was better in highland. There was effective in producing the good yield and fruit quality in highland and the deformed fruits also were decreased. The soluble solid and titratable acidity content increased in highland. Early growth was the most effective in standard solution $(EC\;0.75dS\;m^{-1})$ and had a tendency to be inhibition with increasing nutrient concentration. Standard solution was also the highest to yield about 2,064kg/10a among treatments, and 2/3S, 4/3S, 5/3S by turns. The browning roots and root activity increased when the solution strength was increased, especially in EC $1.25dS{\cdot}m^{-1}$. The soluble solids and acidity content of fruits were increased with higher solution strength. Therefor, the summer hydroponic culture of 'Pechika' ever-bearing strawberry was suitable in highland and effective in standard solution $(EC\;0.75dS{\cdot}m^{-1})$ in solution control.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.4
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• pp.269-274
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• 1994

An experiment was carried out to investigate the effects of irrigation period on the yield and quality of melon (Cucumis melo L.) cultivated in green house 1992~1993. Four different irrigation period was applied ; from transplanting to harvest(Irrigation I), from initial flowering to 35 days after flowering(Irrigation II), from initial flowering to 20 days after flowering(Irrigation III), from initial flowering to 5 days after flowering(Irrigation IV). The water was applied by drip irrigation when the soil water potential of 15cm depth reach at -0.5bar. The results obtained were as follows ; 1. The amount of water applied during the periods were 170.5mm, 145.0mm,126.9mm and 78.8mm for irrigation period I, II, III and IV, respectively. 2. Average evapotranspiration during the cultivation of melon was 3.31mm/day. Evapotranspiration was the highest at the period from 5days after flowering to 15days after flowering. 3. The total yield was increased with the higer amount of water applied, and the yield was in the order of Irrigation I, II, III and IV. However, the yield with economically high quality was the highest in Irrigation III. 4. The sugar content and quality of Net form were decreased with higher irrigation amount.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.63-69
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• 2015

This study was conducted to measure the effect of PE film mulching and irrigation methods on the growth, yield and antioxidant activity of potatoes tubers, in order to examine the possibility of cultivating potatoes in winter season in vinyl greenhouse on the reclaimed tidal land with weak ground inside the sea wall currently completed. The test was conducted on the sandy loam soil (Munpo series), and its salt concentration was 0.42% at the time of planting. The emergence speed per kind of PE film mulching was in the order of black > coloration > transparent > green color, with the black color showing the fastest speed. The temperature change during a day per kind of PE film mulching was in the order of transparent > coloration > green > black color. As for the salt concentration in the soil for each different way of water management, the salt concentration in the treatment of drip irrigation with 1 week interval was lower than that drip irrigation with 2 weeks interval. As for the growth of above-aerial part, plant length was higher, number of tiller and leaves were more and dry weight of above-aerial part was larger in the treatment of drip irrigaton with 1 week interval than drip irrigation with 2 weeks interval. As for the yield of potatoes depending on each way of water management, the yield in the treatment of drip irrigation with 1 week interval was more than drip irrigation with 2 weeks interval. The yield for each different kind of PE film mulching in the weekly drip-irrigation management section was in the order of transparent ${\geq}$ black ${\geq}$ coloration ${\geq}$ green color. In both of total phenol content and DPPH free radical activity experiments, the content and activity were higher with pear color vinyl treatment.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.289-289
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• 2009

당근은 우리나라에서 재배되고 있는 채소 중에서 대표적인 비타민 A의 급원으로서 매우 중요한 근채류이다. 최근 친환경농산물에 대한 관심과 요구가 급증하면서 소비자들은 고품질 당근을 선호하고 있으나 유기농 당근생산에 대한 연구가 미비한 실정이다. 본 연구는 관행 및 유기농 재배가 당근의 생육과 품질에 미치는 영향을 구명하고자 실시하였다. 본 실험에 사용된 공시품종은 '조춘5촌당근'(세미니스, A), '선홍봄5촌당근'(농우종묘, B), '홍심5촌당근'(대농종묘, C), '춘홍5촌당근'(사카타, D), '하파5촌당근'(신젠타종묘, E), '홍심5촌당근'(경신종묘, F)으로 전체 6개 품종이며, 경기도 평택시 유천동 대농종묘(주) 육종연구소 N2, N3 하우스에 9월 8일 파종하였고 재배방법은 유기농 및 관행재배표준법에 준하여 실시하였다. 관행과 유기농 재배 후 12월 3일에 수확하여 엽중, 근중, 근장, 근경, 코어, 추근성, 근피색과 가용성 당함량을 조사하였다. 근피색은 Colorimeter(Minolta, CR-400)를 이용하여 Hunter값인 L(밝기), a(녹색-적색), 그리고 b(파란색-노란색)로 표시하였다. 가용성 당함량 조사는 HPLC를 이용하여 분석하였다. 엽중은 유기농 재배 F품종에서 26.0g으로 가장 무거웠고 전체적으로 유기농 재배구에 비해 관행 재배구에서 엽중이 무거웠다. 근장은 모든 품종에서 관행구에 비해 유기농 재배구에서 현저히 길게 나타나 재배 방법 간의 유의차를 보였으며 유기농 재배의 경우 근장이 17.9cm ~ 19.0cm 범위로 품종간 유의성은 없었다. 근중은 전체적으로 관행 재배구가 우수하거나 유기농 재배구와 비슷한 경향을 보였고, 특히 관행 재배구 B품종이 58.1g, A품종이 57.1g으로 가장 무겁게 나타나 재배방법 및 품종간 비교에서 우위를 나타냈다. 당근 뿌리의 명도를 나타내는 Hunter L값은 모든 품종에서 관행 재배구가 높게 나타났으며 특히 관행재배구의 최하위 L값(45.80)이 유기농 재배구의 최상위 L값(44.81)이 보다 높게 나타나 관행 재배를했을 경우 뿌리 광택이 더욱 우수함을 알 수 있었다. Hunter b값은 노란색을 나타내는데 B품종에서 유기농 재배구 19.68, 관행 재배구 19.55로 모든 품종 중에서 가장 높은 수치를 보였다. Fructose 함량은 D품종이 관행 재배구와 유기농 재배구에서 각각 $8.5mg{\cdot}g^{-1}FW,\;8.3mg{\cdot}g^{-1}FW$을 함유하여 가장 많게 나타났고, glucose 함량은 관행 재배구에서 D품종이 $41.5mg{\cdot}g^{-1}FW$을 함유하여 가장 많았고 유기농 재배구에서도 역시 D품종이 $35.7mg{\cdot}g^{-1}FW$을 함유하여 가장 많게 나타났다. Sucrose 함량은 모든 품종의 관행 재배구에서 현저하게 높게 나타났다. 가용성 당함량은 F품종만이 유기농 재배구에서 높게 나타났지만, 다른 5개 품종의 관행 재배구와 비교했을 때는 가장 적은 수치를 나타내 적절한 비배관리를 통한 관행 재배 방법이 가용성 당함량을 증가시킨 것으로 생각된다. 결론적으로 생육 및 품질은 관행재배에서 유기농 재배에 비해 우수하였고 근장은 유기농재배에서 길게 나타났고 가용성당람량 역시 관행재배에서 대체적으로 높게 나타났지만 품종에 따라 유기농재배에서도 높게 조사된 것도 있어 앞으로 유기농 재배에 적합한 당근 품종선발이 필요하다.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.715-725
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• 2012

This study was performed to make the method of food waste manufacturing for feeding to earthworm and different ratio of earthworm cast was investigated for applying vegetable plants that cultivated in a family or roof garden. We made conventional treatment of gardening soil and prepared soils with earthworm cast (the only fertilizer) at 30, 50, 70 and 100% for planting vegetable plants and then we studied its growth feature. The treatment was repeated three times with 12 weeks for each time. The cultivation of radish and chinese cabbage were managed at the same cultivation level for RDA standard cultivation method, and each sample of soils and plants was analyzed by appropriate analysis method. The growth investigation was performed 12 week after planting, and as for growth characteristics, height, leaf diameter, leaf number, leaf length, fresh weight and dry weight were investigated. The chemical characteristics, soils and plants, were surveyed. As for the growth characteristics investigated, radish and chinese cabbage showed the biggest growth in 70% and 50% treatment with average growth of all characteristics, height, leaf diameter, leaf number, leaf length, fresh weight and dry weight, respectively. Applying these results, a new equation for vermicast recommendation for radish and Chinese cabbage in summer (June-August) was presented. The earthworm cast 50% level with the gardening soil showed the high production in chinese cabbage. In case of radish, earthworm cast 70% with gardening soil level showed great growth, significantly.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.193-199
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• 2007

This study was conducted to explain degree of injury caused by P. panopealis larva which is the key component to develop economic injury level or control threshold in green perilla and was carried out in polyvinyl houses at Yuseong Daejeon, Geumsan and Yesan Chungnam from 2004 to 2006. Of 5 major pests in green perilla polyvinyl house, P. panopealis larva injured green perilla leaf by 48.5% on average under no insecticides application. The peak occurrence of P. panopealis adult was early August and late September in 2004 and 2005 studies. The feeding amount of P. panopealis larva among 1st to 3rd instar was not different, but from the 4th instar the feeding amount greatly increased and this result was consistent with daily feeding experiment in which the amount greatly increased from seventh day. The degree of injury which was investigated with different larval infestation levels showed that the degree of injury increased a little but was not dim ε rent significantly as the density increased. The density of P. panopealis larva in damaged green perilla plant was less than three individuals/plant. This result indicates that P. panopealis adult lays egg on green perilla leaf dispersedly and larva hatched from egg injures only the leaf which egg is layed. These preliminary data seems to be very useful to design economic injury level and control threshold studies for P. panopealis in green perilla polyvinyl house.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.367-370
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• 2007

To make the soil moisture proper is the important factor in the seedbed cultivation of Yangjik for producing a good quality of ginseng seedling. This study was carries out to investigate the effect of soil moisture on photosynthesis and yield of ginseng seedling under the different condition of the soil moisture, such as $100{\sim}400$ mbar. Photosynthesis rate was decreased gradually by the reduction of soil moisture, and in particular it was decreased distinctly under the lower condition of soil moisture, such as $300{\sim}400$ mbar. Photosynthesis rate in air temperature of $30^{\circ}C$ was decreased more distinct than that of $25^{\circ}C$, Light saturation point of leaves was at the quantum of $600{\mu}mol/m^3/s$ at $25^{\circ}C$ while it was decreased by $300{\mu}mol/m^3/s$ at $30^{\circ}C$ according to the increase of air temperature. Respiration rate was increased by the increase of quantum, and decreased by the reduction of soil moisture. Respiration rate under the condition of high quantum was increased regardless of air temperature, but it was decreased distinctly under the condition of low soil moisture and high air temperature, such as 400 mbar at $30^{\circ}C$. There were a gradual decrease by the reduction of soil moisture in leaf length, leaf width, chlorophyll content, and water content of leaves, but heat injury ratio was increased distinctly by the reduction of it. Total root weight, root weight per plant, the yield of usable seedling were decreased by the reduction of soil moisture, and optimal content of soil moisture to produce a good quality of seedling was 63% of field capacity or 18.9% in absolute soil moisture content.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.58-67
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• 2014

The outdoor mass cultivation is not possible for microalgae in Korea all year round, due to cold winter season. It is not easy to maintain proper level of productivity of microalgae even in winter. To prevent a drastic decrease of temperature in a greenhouse, two layers were covered additionally, inside the original plastic layer of the greenhouse. The middle layer was made up of plastic and the inner layer, of non-woven fabric. Acrylic transparent bioreactors were constructed to get more sunlight, not only from the upper side but also from the lateral and bottom directions. In winter at freezing temperatures, six different culture conditions were compared in the triply covered, insulated greenhouse. Wastewater after anaerobic digestion was used for the cultivation of microalgae to minimize the production cost. Water temperature in the bioreactors remained above $10^{\circ}C$ on average, even without any external heating system, proving that the triple-layered greenhouse is effective in keeping heat. Algal biomass reached to 0.37g $L^{-1}$ with the highest temperature, in the experimental group of light-reflection board at the bottom, with nitrogen and phosphorus removal rate of 92% and 99%, respectively. When fatty acid composition was analyzed using gas-chromatography, linoleate (C18 : 3n3) occupied the highest proportion up to 61%, in the all experiment groups. Chemical oxygen demand (COD), however, did not decrease during the cultivation, but rather increased. Although the algal biomass productivity was not comparable to warm seasons, it was possible to maintain water temperature for algae cultivation even in the coldest season, at the minimum cost.