• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.86-93
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• 2018

This present study was conducted to develop the domestic cultivation kit using water celery(Oenanthe Stolonifera DC.) seed. As the result of germination rates in 3 type inbred lines, the IT 232354 had the highest initial germination rate and final germination rate, and was selected as the inbred line to be used in the cultivation kit. The development of the domestic cultivation kit was carried out using the IT 232354 seeds. It was possible to cultivate up to 3 times harvest using the same root in this cultivation kit, though the growth decreased rapidly in the $4^{th}$ cultivation. As a result of investigating the effects of the type of nutrient solution on growth of water celery, the overall growth was the lowest in the nutrient solution for Oenanthe Stolonifera DC.(N.S.D.). The shoot growth was similar to that of nutrient solution for leaves and stem vegetables (N.S.L.S.) and amino acid fermentation by-product liquid (A.F.B.L.), however in the root growth, the N.S.L.S. was more effective than A.F.B.L. When it was harvested 4 times consecutively after 1 time of planting, the last survival ratio of A.F.B.L. was 100% while their ratios were 96.4% and 49.8% each for N.S.L.S. and N.S.D. For the growth by cultivation kit type, the hole type cultivation kit increased slightly compared to the 3 hole type cultivation kit in the $1^{st}$ and $2^{nd}$ harvest, but there was no difference in the $3^{rd}$ and $4^{th}$ harvest. Total yield of one cultivation kits showed the 3 hole type cultivation kit is much higher than the 2 hole type cultivation kit. According to the results of this experiment, it is possible to harvest three times by planting one times if it was cultivated using N.S.L.S. and A.F.B.L. in the 3 hole type cultivation kit.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.424-431
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• 2017

This study was conducted to set the optimum nutrient solution concentration by growth stage for new strawberry cultivars 'Berrystar' and 'Jukhyang'(Fragaria ${\times}$ ananassa Duch. cvs. 'Berrystar', 'Jukhyang') grown through hydroponics to improve the quality and yield. Three different EC levels were applied to the nutrient solution. The treatment levels were 0.7, 1.0 and 1.3 times higher than the nutrient concentration standard for 'Seolhyang' based on the 'Manual for strawberry cultivation' of Rural Development Administration. Based on the results, there were no significant differences in growth of 'Berrystar' by EC level. 'Jukhyang' showed the most vigorous growth grown in 1.3 times higher nutrient concentration. While the growth of 'Berrystar' and 'Jukhyang' grown in higher EC level has leaves with more chlorophyll concentration. However the quantum yield of leaves was not affected by the treatments. On the treatment with 1.3 times higher EC level, the weight, length, width and firmness of 'Berrystar' and 'Jukhyang' were significantly high. The sugar contents of the harvest analyzed by HPLC did not differed particularly, but the percentage composition of reducing sugar and non-reducing sugar were presented differently depending on the treatments. Marketable fruit yield increased as nutrient concentration increases. However, there were no large differences by treatments. Meanwhile, 'Jukhyang' showed significant difference by nutrient concentration and had the largest yield for a treatment grown in 1.3 times higher EC level. Based on these results, it is recommended to provide the same nutrient solution concentration level to the nutrient concentration standard of 'Seolhyang' for 'Berrystar', and the 1.3 times higher level for 'Jukhyang'.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.406-411
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• 2011

This study was conducted to find out the effect of cut-off period (0 hour, 3 hours, 6 hours, 12 hours, and 24 hours) to supply nutrient solution for chicon forcing at that was predrying treatment on the storability of chicon. The cut-off treatment increased dry matter rate, respiration rate, and ethylene production rate. The dry matter rate of chicon increased, as the cut-off period increased, but the respiration rate and ethylene production rate of chicon was highest in 12 hours and 6 hours cut-off treatment, respectively, and then their rates decreased, as the cut-off period prolonged. The weight loss at cut-off 6 hours treatment was lower than other treatments during $10^{\circ}C$ storage temperature. The cut-off 6 hours treatment showed higher carbon dioxide and oxygen concentration in 10,000 cc/$m^2$/day/atm oxygen permeability film package during storage period than control and showed a little predrying effect but was not statistically significant. At $4^{th}$ day, the ethylene concentration reached higher than other storage day and after that decreased but was not statistically significant. The quality of chicon for 3 hours, 6 hours, 24 hours cut-off treatments on storability showed higher than other treatments, accordingly. The 6 hours cut-off treatment showed the inhibited effect of the degree of browning of chicon cutting plane. The effect of 6 hours cut-off treatment on storability of chicon showed proper predrying effect, reduced moisture loss and browning inhibition apparently during $10^{\circ}C$ storage.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.332-340
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• 2018

Supplemental lighting with artificial light sources is a practical method that enables normal growth and enhances the yield and quality of fruit vegetable in greenhouses. The objective of this study was to investigate the effect of sulfur plasma lamp (SP) and high-pressure sodium lamp (HPS) as supplemental lighting sources on the growth and yield of paprika. For investigating the effectiveness of SP and HPS lamps on paprika, the effects of primary lighting on plant growth were compared in growth chambers and those of supplemental lighting were also compared in greenhouses. In the growth chamber, plant height, leaf area, stem diameter, number of leaves, fresh weight, and dry weight were measured weekly at SP and HPS from 2 weeks after transplanting. In the greenhouse, no supplemental lighting (only sunlight) was considered as the control. The supplemental lights were turned on when outside radiation became below $100W{\cdot}m^{-2}$ from 07:00 to 21:00. From 3 weeks after supplemental lighting, the growth was measured weekly, while the number and weight of paprika fruits measured every two weeks. In the growth chamber, the growth of paprika at SP was better than at HPS due to the higher photosynthetic rate. In the greenhouse, the yield was higher under sunlight with either HPS or SP than sunlight only (control). No significant differences were observed in plant height, number of node, leaf length, and fresh and dry weights between SP and HPS. However, at harvest, the number of fruits rather than the weight of fruits were higher at SP due to the enhancement of fruiting numbers and photosynthesis. SP showed a light spectrum similar to sunlight, but higher PAR and photon flux sum of red and far-red wavelengths than HPS, which increased the photosynthesis and yield of paprika.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.166-172
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• 2019

BACKGROUND: Increase in the ratio of small berries in blueberry production decreases the farmers' profits due to weakening market competitiveness and lowering harvest efficiency. One of the reasons for increased small berries is over fruit-load. For improving productivity and competitiveness of blueberry in Korea, hand-thinning can be applied to increase fruit quality before the developing adequate chemical thinning methods. This study was conducted to investigate the proper timing and methods for floral buds thinning in rabbiteye blueberry. METHODS AND RESULTS: Eight years old bushes of rabbiteye bluberries 'Brightwell' as a primary cultivar and 'Powderblue' as a pollinizer were used for this study. Fruit size distribution by leaf-to-fruit ratio was investigated by counting the number of leaves and fruits in canes of 127 'Brightwell' plants whose fruit set varied. Fifty percent of flowers/floral buds were removed in four different floral buds stages such as bud swell, late pink bud, full bloom, and petal fall, and the consumed time for thinning and fruit characteristics were recorded to investigate the effect and proper timing of floral buds thinning. Fruit weight and soluble solids content tended to increase in proportion to leaf-to-fruit ratio and the production of the number of fruits less than 13 mm in diameter decreased when leaf-to-fruit ratio was more than 2.5. Manual floral buds thinning by hands was fastest in full bloom stage and slowest in bud swelling stage. In all cultivars, fruit size was significantly smaller in non-thinning treatment than thinning, and there was, however, no significant difference in total fruit yield. The number of fruits less than 13 mm in diameter increased in both cultivars as floral buds thinning was delayed. Consumed time for picking 90% berries out of total berries per bush was shortest in full bloom stage thinning in 'Brightwell' and bud swelling, full bloom thinning in 'Powderblue'. These were 25 and 20 days faster than no thinning, respectively. CONCLUSION: Although the effect of floral buds thinning varied depending on the cultivars, our results confirmed that floral buds thinning was effective for the early intensive harvesting and the increase of the large fruit ratio and the harvesting productivity. Also, in order to increase thinning efficiency, it is recommended to remove the flower buds before the full bloom stage.

• 농업기술회보
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• v.48 no.2
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• pp.30-31
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• 2011

최근 이상기온에 따른 환경의 변화로 그동안 문제되지 않았던 병해충이 많이 발생되어, 벼농사에 큰 피해를 주고 있는 실정이다. 특히 키다리병 줄무늬잎마름병, 흰잎마름병이 많이 발생되어 수확을 하지 못할 만큼 큰 피해를 주고 있다. 벼에 발생되는 주요 병해를 중심으로 발생원인을 알아보고, 방제요령을 실천하여 2011년 고품질 벼 생산으로 농가소득에 도움이 되고자 한다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.07a
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• pp.274-281
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• 1999

청과물은 품종, 재배기술, 환경의 요인 등에 영향을 받아 품질, 형상, 색택, 병충해의 상해정도가 다르게 나타남에 따라 농산물의 다양한 상품성이 결정된다. 또한 수확, 저장, 포장. 수송, 상하차 등 유통과정에서의 취급여하에 따라 기계적으로 손상을 받음은 물론 유통기간이 길어짐에 따라 호흡 및 증산작용 등 생리적 작용으로 부패 및 변질이 진행되어 유통과정 중 농산물의 품질저하가 상당한 수준에 이르고 있으나, 이에 대한 관심은 매우 빈약한 실정이다. (중략)

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.156-161
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• 2003

농약과 방제기가 개발되면서 적은 노력과 비용으로 넓은 면적의 작물을 병과 해충으로부터 보호할 수 있게 되어 수확량이 대폭 늘어나고 농사도 안정적으로 지을 수 있게 되었다. 이렇게 방제작업이 손쉽게 되었으나 농약을 필요량보다 적게 뿌릴 경우 병해충을 충분히 방제할 수 없고, 많이 뿌릴 경우 비용과 환경오염을 증가시키는 또 다른 문제점에 부닥치게 되었다. 현재 사용되고 있는 방제기로 농약을 살포할 경우 노출된 작물의 잎에서는 농약이 흘러내리는 반면 수관내부에 감추어진 잎이나 병해충이 주로 발생되는 잎 뒷면은 농약 부착이 미흡하다. (중략)

• The Science & Technology
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• v.6 no.8 s.51
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• pp.25-28
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• 1973

좁은 면적에서나마 좀더 많은 수확을 얻으려는 노력은 부단히 계속되고 있다. 그러나 인구는 나날이 불어가고 경작면적은 제한되어 있기 때문에 그 문제점은 더욱 커지고 있는 것이다. 소위 재배에 적합하다는 고래로부터의 농경지에서만이 식량생산이 가능한 것일까? 하지만 이는 옛말이 되고 말았다. 모래밭에서 노다지를 캐낼 수 있기 때문이다. 고대 농대의 김용길 교수는 녹색식물의 영양, 생장, 광합성에 관한 능력발휘의 어느한계 이상에서는 토양이 오히려 제한적 인자로 등장한다고 지적하면서 이와같은 단점을 배제한 관권농법과 모래땅의 식물재배법을 연구 발표하였다. 토양의 제한성을 제거하고 근권매지에 새로운 영양환경을 조성하여 작물생산능력을 극대화하자는 것이 김교수의 주장이다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.249-254
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• 2002

온실에서 환기는 외기와의 공기교환을 통한 온도 및 습도의 조절뿐만 아니라 이산화탄소 등의 가스농도를 조절함으로써 온실내 공기의 쾌적성 확보와 실내기류의 형성으로 인한 작물의 생육촉진에도 중요한 역할을 담당한다. 그러므로, 작물생육환경의 최적화를 통한 품질향상 및 수확량 증대를 목적으로 하는 온실재배에 있어서 환기특성 분석 및 공기유동 예측은 가장 기본적인 설계요소라 할 수 있다. (중략)