• Horticultural Science & Technology
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• v.28 no.5
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• pp.743-749
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• 2010

Objective of this research was to investigate the effect of various potassium concentrations in fertilizer solution on growth of and nutrient uptake by 'Chugyang' eggplant ($Solanum$ $melongena$ L.). Tissue analyses were conducted to determine the threshold levels of potassium in plants when disorders develop for potassium. The lower leaves of K deficient plants became spotted, yellowing in color, and finally necrosis occurred. The necrosis spread inward and upward. K toxic plants developed necrotic spot at the margin of old leaves and the surface of old leaves were twisted. The tissue K contents in the most recently fully expanded leaves and dry weight of full above ground plant tissue at 35 days after transplanting showed linear and quadratic response to elevated K concentrations with the equation of y=1.127+0.3147x ($R^2$=0.8916) and y=14.92+2.2743x-$0.1402x_2$ ($R^2$=0.8659). When 10% reduction in dry weight set to threshold levels, optimum tissue K contents are in the range from 2.1 to 5.1%. The yield through 150 days after transplanting and tissue K contents at 150 days after transplanting also showed quadratic and linear responses to elevated potassium concentrations in fertigation solution with the equation of y=153.24+345.5x-$18.46x^2$ ($R^2$=0.8620) and y=0.9921+0.3860x ($R^2$=0.9611), respectively. When the 10% reduction in yield is set to threshold levels, the tissue K contents for maximum yield should be around 3.4% to 5.9% in most recently fully expanded leaves.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.4
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• pp.35-42
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• 1980

To establish a generation acceleration technique, two crops a year at field condition of Suweon, 10 varieties different in their spring growth habit were tested with 6 different seeding time after harvesting. These materials were harvested on June 10, 19, 79 and tested for their seed production ability at varions seeding time from July I I to August 15 with a week interval. An immatured seed germination technique and green vernalization methods were applied in cycling generations and the results obtained were summarized as follows. 1. In summer growing, seedlings establishment after transplanting was better in earlier transplanting. 2. Heading time was remarkably enhanced by earlier transplanting. Considering the results of two years early or mid of July was the suitable time to plant the second summer crop. 3. Those varieties of spring growth habit expressed little variations in plant height among the varieties. In 1978 which is referred as warm year produced plant height as tall as 8-16cm and poor crop but produced good crop with 25-65cm plant height in 1979. 4. No definit tendency in the length of spike was. observed among the cultivars but longer spike was found in winter wheat compared to the spring. 5. Number of spikes per plant was ranged from 1 to 3 regardless the transplanting time in 1979. However, more spikes per plant were produced in early or mid of July transplanting and those varieties of higher growth habit than V did not produces any spikes. 6. Higher number of grains per spike was found at earlier transplanted varieties. Therefore, it is concluded that those materials of I-IV growth habit with mid or early July transplanting would be suitable in practical sense considering their ability of seed production. 7. Two-year results indicated that wheat crop can not tolerate the temperature level higher than average 32$^{\circ}C$ C at Suweon. In this regard, the cultivation schedule was established assuming average temperature condition like the year of 1979 which was possible to grow wheats.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.351-358
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• 2021

The study was investigated to compare growth characteristics, the antioxidant activity, and the triterpenoid content of two Centella asiatica cultivars ('Giant Tiger Care' and 'Good Tiger Care'). At 41 days after transplanting, lengths of leaf and petiole were significantly longer in 'Good Tiger Care' than in 'Giant Tiger Care'. However, the growth characteristics (leaf area, petiole thickness, petiole length, and weight) were greater in 'Giant Tiger Care' than in 'Good Tiger Care' at 104 days after transplanting (harvest time). Antioxidant activity and total phenol content in four extracts (WE, water extract; HWE, hot water extract; 50E, 50% EtOH extract; 70E, 70% EtOH extract) of the two cultivars were high in 70E of 'Giant Tiger Care'. As a result of the triterpenoids analysis, the major triterpenoids of the two cultivars were identified as madecassoside and asiaticoside. The total triterpenoid content was high in 50E and 70E of 'Giant Tiger Care' and 'Good Tiger Care', respectively but the total triterpenoid content was highest in Good Tiger Care'. However, at the 104 days after planting, the yield of 'Giant Tiger Care' was three times higher than that of 'Good Tiger Care'. In addition, the total triterpenoid content that can be produced in the same cultivation area (3.3m²) was 2.459mg in 50E of 'Giant Tiger Care', which was ~2.2times higher than that of 70E of 'Good Tiger Care' (1.103 mg). Thus, it is considered economical to cultivate 'Giant Tiger Care' which has the highest antioxidant activity and high total triterpenoid production per cultivation area.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.103-104
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• 2003

어류의 양식생산 과정중에는 사육중인 어류에게 스트레스로 작용할 수 있는 여러 가지 요인들이 있다. 그 중에서도 생산된 종묘의 양식장 운송, 수확한 어류의 소비지 운반 등은 양식과정중 피할 수 없는 작업이다. 어류의 수송 후에는 혈장 corticosteroid, glucose, 전해질, 삼투질 농도, 적혈구수, hematocrit, hemoglobin 등이 변화하는 것으로 알려지고 있다(Chang et al. 2001; Hur et al., 2002, 2003). 스트레스 요인별 연구로는 염분, 수온, 밀도 및 마취제에 관한 것 등이며, 아울러 이들의 복합적인 요인에 대하여 스트레스 반응을 최소화시키려는 연구가 진행되고 있다. 어류종묘의 수송이나 수확된 어류가 대량으로 수송되고 있으므로, 넙치(Paralichthys olivaceus)와 같은 대량수송 어류의 수송에 따른 스트레스 반응에 대한 연구의 필요성이 제기된다. 그러므로 본 연구에서는 넙치를 사용하여 염분, 수온 및 마취제에 의한 수송이 스트레스 지표로 알려져 있는 혈액학적 요인, cortisol, glucose, lactic acid 및 삼투질 농도 둥에 나타나는 생리학적 반응을 조사하여, 활어수송 과정에서 나타나는 스트레스 반응에 대한 기초자료를 제공하고자 하였다. 실험어는 21.2 cm, 97.4 g인 양식 넙치를 사용하여, 수온은 20℃ (natural water temperature, NWT)와 15℃ (cooling water temperature, CWT), 염분은 해수(35‰)와 15‰해수, 마취제(anesthesia, Anes., MS-222)는 50 ppm의 조건으로 혼합한 실험구를 설정하였다. 실험구는 각각 NWT＋35‰, CWT＋35‰, NWT＋15‰, NWT＋15‰, NWT＋35‰＋Anes., CWT+35‰＋Anes., NWT＋15‰+Anes. 및 CWT+15‰＋Anes.의 8개 실험구를 2반복으로 설정하여 경북울진∼부산까지 약 400 km (6시간)를 차량수송하였다. 수송용기는 스티로폼상자(66×42×20 cnn)로서, 여기에 해수 3 L와 액화산소를 넣은 비닐봉지에 넙치 8마리씩 수용하여 수송하였다. 혈액의 성상 및 분석항목은 수송전ㆍ후에 채혈하여 비교하였다. 수송전 hematocrit는 22.2±3.8%에서 수송후 NWT＋35‰에서 15.3＋3.9%, CWT＋35‰은 16.7±3.0%, NWT+15‰구에서는 19.2±1.8%로 낮아졌으며, CWT+15‰구는 20.9±3.6%로 수송전과 차이가 없었다. 한편 NWT＋15‰＋Anes.구는 17.8±0.9%, CWT＋15‰＋Anes.구는 14.5±1.5%로 낮아졌다. Cortisol은 수송전 2.4±0.1 ng/ml로부터 CWT＋35‰구는 16.7±12.8 ng/ml, NWT＋35‰구는 47.9＋19.8 ng/ml, NWT＋15‰구는 43.5±13.9 ng/ml, CWT＋15‰구는 26.1±8.3 ng/ml, NWT＋15‰+Anes.구는 61.7±3.3 ng/ml, CWT+15‰+Anes.구는 86.1±19.0 ng/ml로 높아졌다. Glucose는 수송전 74.2±32.6 mg/dl로부터 NWT＋35‰구는 197.9±27.5 mg/dl, CWT＋35‰구도 272.1±29.9 mg/dl로 유의하게 높아졌다. Na/sup +/의 수송전 농도는 163.5±0.6 mEq/L로부터 NWT＋35‰구와 CWT＋35‰구는 각각 175.3±1.2 mEq/L, 190.0±5.0 mEq/L로 높아졌으며, 다른 실험구에서는 차이가 없었다. 본 연구 결과, cortisol과 glucose에서 수송전보다는 모든 실험구에서 높게 나타나 수온, 염분 및 마취제를 사용하여도 스트레스를 받고 있는 것으로 나타났다. 특히, cortisol의 경우, 수온과 염분만을 혼합한 실험구보다 마취제를 혼합한 실험구에서 높게 나타났다. 다른 혈액학적 항목에서는 염분과 마취제를 사용하지 않았던 실험구인 NWT＋35‰구와 CWT＋35‰구에서 다른 실험구에 비하여 glucose, Na/sup +/ 및 Cl/sup -/ 등에서는 높게 나타나는 경향을 보였다.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.4
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• pp.274-280
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• 2001

The chemical forms of calcium compounds in perilla leaves and their changes after harvest were investigated. The four types of calcium compounds extracted were as follows: water soluble calcium(F-I: mainly water soluble organic acid salts and calcium ion), IN-sodium chloride soluble calcium(F-II: calcium-pectate and calcium-carbonate), 2%-acetic acid soluble calcium(F-III: calcium-phosphate), and 5%-hydrochloric acid soluble calcium(F-IV: calcium-oxalate). The calcium content of perilla leaves was not found to vary with their age. Relatively high levels of F-l (28.4~39.5) and F-II (34.4~47.4) were found in young and mature leaves while the F-IV constituted 15.6~21.6% of the total calcium. The F-IV calcium contents of perilla. spinach and jaso were 16.8, 42.4 and 22.3%, respectively. In contrast to calcium. magnesium existed as water soluble magnesium at the highest content of 90.6% in spinach while 62.9% and 16.8% of the total magnesium existed as water soluble magnesium in perilla and jaso, repectively. The change in vitamin C and F-IV calcium content were examined for 7 days after harvest. Vitamin C content decreased slowly at the beginning but rapidly from the 4th day after harvest. On the other hand, the F-IV calcium content increased slowly at the beginning and rapidly from the 4th day of observation. This result suggests that the increase in F-IV calcium is related to the decrease in vitamin C content. This phenomena was more distinctly observed at 2$0^{\circ}C$ than 5$^{\circ}C$.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1037-1042
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• 2012

An auxin-producing bacteria (2SJ8-02) was isolated from waste mushroom bed of Agaricus bisporus in Buyeo-Gun, Chungnam. The strain 2SJ8-02 was classified as a novel strain of Pantoea rwandensis based on a chemotaxanomic and phylogeneticanalyses. The isolate was confirmed to produce indole-3-acetic acid (IAA), one of auxin hormones, by TLC and HPLC analyses. The maximum concentration of IAA, $122mg\;L^{-1}$ was detected from the culture in R2A broth containing 0.1% tryptophan for 24 h at $35^{\circ}C$. The molecular weight of the main peak obtained by LC-mass analysis was 175 corresponding to that of IAA. To investigate the growth-promoting effects to the crops, the culture broth of Pantoea rwandensis 2SJ8-02 was infected to water cultures and seed pots of mung bean. In consequence, the adventitious root induction and root growth of mung bean were two times higher than those of the control.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1007-1016
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• 2003

Garlic was stored at 4, 8, and $12^{\circ}C$ to investigate the development of green discoloration. Green discoloration developed after 7 day of storage ar $4^{\circ}C$, while it developed after 15 day of storage at 8 and $12^{\circ}C$. The effect of maleic hydrazide fertilization on green discoloration of garlic was not observed. Green discoloration of garlic was accelerated by gamma-radiation treatment. The addition of cysteine did not prevent green discoloration, which decreased the commercial value of the garlic due to the presence of white specks on the surface. When 3% ascorbic acid was added to the garlic, green discoloration developed in 6 and 24 hr at room temperature and $4^{\circ}C$, respectively. The tendency of garlic to discolor was also investigated at various storage temperatures. Discolored garlic stored for 30 day at low temperatures was conditioned at $20{\sim}45^{\circ}C$ for 20 day. The green discoloration of garlic conditioned at 20 and $25^{\circ}C$ did not disappear in 20 day, but disappeared in 20 day when conditioned at $30^{\circ}C$. The L, a, and b values of garlic conditioned at 35, 40, and $45^{\circ}C$ for 4 day were similar to those of normal garlic. Conclusively, our results indicated that the best method for suppressing green discoloration was conditioning discolored garlic at $35^{\circ}C$ for 4 day.

• Journal of Animal Science and Technology
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• v.44 no.2
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• pp.251-260
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• 2002

The corn (Zea mays L) planting date in a double-cropping system is delayed until mid-May due to delayed rye harvest on May. This experiment was conducted to determine the optimum harvesting time for high yield and the best quality of silage corn at late planting date after harvesting winter rye. Corns were planted on 21 May and harvested at eight different maturity stage at Seoul National University Experimental Livestock Farm, Suwon in 1997. Maturities were B (blister; 16 days after silking), M (milk; 20 days), LM (late milk; 24 days), SD (soft dough; 28 days), ED (early dent; 33 days), FD (full dent; 38 days), LD (late dent; 44 days) and PM (physiological maturity; 53 days) stages. The percentage of whole plant dry matter (DM) showed optimum range for silage making (29.0 to 38.5%) when corn plant was harvested at between ED and LD stages. Maximum whole plant DM (14,831 kg/ha) and total digestible nutrients (TDN) yields (10,675 kg/ha) reached at full dent stage. The percentage of whole plant acid detergent fiber (ADF) was decreased from 35.4 to 22.1%, and that of neutral detergent fiber (NDF) was also decreased from 63.8 to 46.0% as harvest stage progressed. These changes in chemical compositions were associated with changes in plant part composition. A progressive increase in total ear, and the decrease in stover portion in the plant were observed with advance in harvest stage. Calculated on net energy for lactation (NEL) and TDN values based on ADF percentage of stover plant decreased by ED stage and then increased by PM stage. But NEL and TDN values of ear and whole plant increased as harvest stage progressed. While in vitro dry matter digestibility of stover was decreased from 61.1 to 49.7%, whole plant was increased from 58.3 to 65.7% as maturity advanced (P$<$0.05). The results of this study indicate that corn can be harvested for silage at full (1/2 milkline) and late dent (2/3 milkline) stages for maximum yield and optimum quality at late planting. And days after silking at late planting was 38 and 44 days.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.459-464
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• 2002

This experiment was conducted to know the changes of bioactive component content in four-year-old peony (Paeonia lactiflora Pall.) root with various drying methods such as room temperature drying, $50^{\circ}C$ heat-air drying, room temperature drying after $80^{\circ}C$ boiling water treatment and freeze drying, and to establish the optimum drying method for high quality production of Paeoniae Radix. For this purpose, the contents of paeoniflorin, albiflorin and five phenolic compounds (gallic acid, benzoic acid, (+)-catechin, (-)-epicatechin and (+)-taxifolin 3-O-$\beta$-D-glucopyranoside) in peony root with different drying methods were analyzed by RP-HPLC. The contents of paeoniflorin, albiflorin and (+)-taxifolin 3-O-$\beta$-D-glucopyranoside at room temperature drying were higher than in the other drying methods and that of gallic acid at 8$0^{\circ}C$ boiling water treatment was the highest among that of all drying methods. In the case of freeze drying, the contents of (+)-catechin, benzoic acid and (-)-epicatechin were the highest among those of all drying methods. As increase of drying and treatment temperature, the contents of paeoniflorin, albiflorin, (+)-taxifolin 3-O-$\beta$-D-glucopyrano-side, (+)-catechin and benzoic acid were decreased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.323-329
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• 1987

Five soybean varieties of two early maturing Karikei73 and SS 79168, and three late maturing Tohoku76, Baegunkong and Jangbaegkong were used and evaluated in the study. Of the varieties examined, Karikei73 was characterized by the delayed leaf senescence. The varieties were planted in the pots of 1/3500 a filled with volcanic ash soil at the experimental fields of the National Institute of Agrobiological Resources in Japan. Major agronomic characteristics including the activity of nitrogen fixation for root nodules during the grain filling period were measured. Measurements during the stages were followed by the stage of development descriptions for soybeans made by Fehr and Carviness (1977). The acetylene reducing activity (ARA) per dry weight of root nodule measured using acetylene reduction assays was the highest at R4-R4.5 with decreasing trends thereafter for the early matruing varieties, while it continuously increased up to R6 but decreased rapidly thereafter for the late maturing varieties. The dry weights of root nodules and all parts of the host plant at each stage checked were greater in the late maturing varieties being the same in ARA per pot.