• Journal of Sericultural and Entomological Science
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• v.24 no.2
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• pp.43-54
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• 1983

In a field trial, the influence was studied by measurement of growth and leaf yields and chemical composition (in organic cations and anions and total nitrogen) with two nitrogen dressings (lower nitrogen treatment 25kg and higher nitrogen treatment 75kg urea/10a as the summer fertilizer) after the summer cutting. The results were as follows; 1. With increasingn nitrogen dressing, branch length and weight were enchanced. The fresh weight of leaves was higher to be 273.6kg/10a in the higher nitrogen treatment than in the lower nitrogen treatment on 20 September. 2. The moisture content of leaves lasted above 73% until on 30 August. Afterward it decreased sharply upto 63% on 20 September. In higher nitrogen treatment it was higher about 0.1∼1.8% than in lower nitrogen treatment. The increasing nitrogen dressings combined with leaf condition led to be soft until on 10 October. 3. Dry matter weight of leaves started decreasing around on 10 September, whereas that of branches increased until around 30 September indicating that the dry matter moved to branch and root from leaves. 4. The increase in Ca$\^$2+/ content was particularly evident, whereas the K$\^$+/ and Mg$\^$2+/ decreased with growth. The Ca$\^$2+/ content was much higher in the high nitrogen treatment than in the low nitrogen treatment. 5. With rapid decrease in total nitrogen and water in the leaves around the end of August, the Ca$\^$2+/ and Cl$\^$-/ which were higher in the lower part moved up to the upper part. Whereas the K$\^$+/, H$_2$PO$_4$$\^$-/ and SO$_4$$\^$2-/ which were higher in the upper part moved down to the lower part. 6. Total nitrogen content decreased sharply 3,200me/kg DM to 2,000me/kg DM at the end of August changing the maxmium content of total nitrogen from upper to lower part in the low nitrogen treatment on 12 September and in the high nitrogen treatment on 22 September, and an apex of branches was died and fallen 10 days after respectively. 7. The sum of cation in leaves (∑C) increased from 1400me/kg DM to 1600me/kg DM with growth, wherease that of anions (∑A) was approximatly the same during the whole growing season. As the result, the ionic balance (C-A) increased from 1000me/kg DM to 1200me/kg DM. 8. ∑C, ∑A and (C-A) were higher in the high nitrogen treatment than in the low nitrogen treatment due to be much higher of Ca$\^$2+/ content and higher of NO$\^$-/$_3$, SO$\^$2-/$_4$ and H$_2$PO$_4$$\^$-/ content.

• The Korean Journal of Ecology
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• v.16 no.1
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• pp.63-74
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• 1993

The ecotypic variation of Phragmites communis Trin. was studied from Aug. 1989 to March 1992 in three populations of salt marsh, estuary and fresh water areas of the western coastal regions in Korea. The length growth and aboveground total dry weight of Phragmites communis Trin. From three habitates were measured monthly and the seeds from them collected. Chlorophyll contents, bud number and width of Phragmites communis Trin. populations after their seeds were sown in seedbeds, and the growth of seedlings according to salt contents were also determined. The results lare summarized as follows: The height and basal diameter of shoot, leaf length and width, and total dry weight of Phragmites communis Trin. were very different from each other according to their natural habitats. The bud number of seeds was increased as sample sites moved from estuary to fresh water areas and salt marsh. The but the bud diameter turned out to be in reverse proportion to the bud number. The chlorophyll content of the population from fresh water was $8.6901{\mu}g/ml$, whereas that from estuary and salt marsh was $9.61801{\mu}g/ml$ and $10.3160{\mu}g/ml$, respectively. The average length growth and total dry weight of seedlings grown at different salt contents were compared. Those of fresh water area decreased at salt contents lower than 0.5% in culture solution and those of estuary at higher than 0.5%, but the population of salt marsh was shown to be capable of sustaining itself at 1.0%. All of these results suggested that the populations of Phragmites communis Trin. in the western coastal regions of Korea have undergone ecotypic variations: fresh water type, estuary type and salt marsh type.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.311-317
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• 2004

This study was designed to investigate the effect of Korean traditional tea materials on lead (Pb) accumulation and histological changes in Pb-administered rats. Male rats were divided into six groups: a normal, Pb, and Pb-water extract of Korean traditional tea materials (green tea: GT, persimmon leaf: PL, safflower seed: SS, Eucommia ulmoides: EU) groups. Pb (25 mg/kg BW) was orally administered once a day for 4 weeks. The extract of GT, PL, SS, and EU were administered based on 1.26 g of raw traditional tea materials/kg Bw/day. Pb contents of serum and liver were significantly higher in the Pb group than in the normal group. However the water extracts of GT, PL, SS, and EU administration lowered Pb contents of serum and liver in the Pb-administered rats, respectively. Serum Zn content was significantly higher in the Pb group than in the normal group, whereas, Cu and Fe contents were lower in the Pb group. Hepatic Ca content was significantly lower in the Pb group compared to the normal group. In the present study, water extract of Korean traditional tea materials administration effectively improved Cu and Fe contents of serum and liver. Infiltration of the local inflammation was found in Pb group, whereas water extracts of Korean traditional tea materials administration attenuated histological changes of tissues.

• Korean Journal of Environmental Agriculture
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• v.13 no.1
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• pp.10-17
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• 1994

To investigate differences with the polluted sources on Cu contents in soils and paddy rices under water pollutions, soils with the distance, the surface(0-15㎝ depth) and subsurface(15-30㎝ depth) in 1982 and 1990, and rice plants at the soil sampling sites in 1990 were separately sample at Mangyeong River area under the influence of municipal and industrial waste water from Jeonju city. Soil samples were extracted with $4M-HNO_3$ and plant samples were digested with mixture of $HNO_3$ and $HClO_4$ for analyzing Cu, Cd, Zn, Pb by atomic absorption spectrophotometry. Cu contents in soils ranged from 5.20 to 71.70 mg $kg^{-1}$. Average Cu level in 1990 was higher than that in 1982. Variation of Cu content with the distances from the source of waste water in 1990 was more regularly decreased than that in 1982. A significant correlation was observed between Cu contents in leaf sheath of rice plant and Cu, Zn and Pb contents in soils. Cu contents in soil was correlated with Zn and Pb in soil at area affected by waste water, regardless of years and soil depths. Cu contents in brown rice ranged from 0.4 to 10 mg $kg^{-1}$, and it was the lowest in parts of rice plant, and Cu content in panicle axis was 2.3 times higher than that in brown rice.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.300-310
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• 2022

The objective of this experiment was to investigate the effect of drip irrigation volume on tomatoes (Solanum lycopersicum L.) grown in a greenhouse using perlite medium. Plants were treated by three different irrigation treatment I₀, I₂₅, and I₅₀ (where irrigation volume of I₂₅ and I₅₀ was 25% and 50% higher than I₀, having limited or no leaching). Growth characteristics of plants, yield and water use efficiency were measured. The result showed that plant height, leaf length and leaf width were lowest in the I₀ treated plants. However, these parameters were not statistically significant differences between the plants that were grown in the I₂₅ and I₅₀ treatment. Soluble solids content, acidity and dry matter of 111th, 132nd, and 143rd days harvested tomato were higher in the plants irrigated with lowest volume (I₀) than the higher volume (I₂₅ or I₅₀). In addition, water content was lower in the 111th and 132nd days of harvested tomatoes from the I₀ treatment. The number of big-size tomatoes (>180 g) was significantly higher in the I₂₅ irrigated plants. There was no significant difference in the total number of harvested fruits among the treatments. The average fruit weight and total yield of harvested tomatoes were lowest in the I₀ treated plants. The water consumption of tomato was not significantly different amongst the treatments but water use efficiency was lowest in the I₀ treatment. Principal component analysis revealed that total soluble solid and acidity of tomato showed a positive correlation between each other. These results suggest that I₂₅ was the optimum irrigation treatment for tomato based on its measured growth characteristics, yield and water use efficiency.

• Journal of Korean Society of Forest Science
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• v.8 no.1
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• pp.3-10
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• 1968

(1) The present work is a study on the tolerance of salt concentration, salt injuries and growth, under varied conditions, of salt concentration of five kind silvicultural species. (2) Pinus thunbergii, which is tolerant of stat, has shown both low fresh leaf's pH and low gravity, while Pinus densiflora, Abies bolophylla and Pinus koraiensis have respectively shown high fresh leaf's pH and high gravity. (3) Pinus thunbergii, which is tolerant otosalt, has shown high water content ind its lead, hbile such speciesras Pinus densiflora an Abies lophylla, which are intolerant of salt have shownlow water content in their leaves. (4) A signifficance has ibeen found, in the nonreatment fresh les's pH and n gravity, among Pinusthunbergiis Pinu rigida, Pinus koraiensis, Pinus densiflora and Abies holophya. (5) The order of thetlolerance of salt among the tested species is as foohws : Pinus thunbergii, P. Korea iensis, Abies holopylla. (6) The signs of salt injuries have been observed at the tops of the trees 2~3 hours after the application of 1.5% salt solution in the case of Abiihs holop hylla which are intolerant of salt, while they have been of served at the same position 4~6 hours after the 1.5% application in the case of Pinus Koraiensis and Pinus thunbergii.

• Korean Journal of Medicinal Crop Science
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• v.21 no.2
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• pp.118-123
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• 2013

This study was carried out to select optimal shade materials among four-layered polyethylene (PE) net (FLPN), aluminium-coated PE sheet (APSS), and blue PE sheet (BPSS) in condition of paddy field cultivated 6-year-old ginseng. The order of light-penetrated ratio and air temperature by shade materials was BPSS > APSS > FLPN. Light-penetrated ratio of BPSS before two fold shade was more 3 times and 2 times than that of FLPN and APSS, respectively. Air temperature of BPSS was also higher $1.6^{\circ}C$ and $1.4^{\circ}C$ than that of FLPN and APSS, respectively. BPSS showed good cultural environment because all of light-penetrated ratio and air temperature were become higher in spring and fall season but lower in summer season by additional shade with two-layered PE net. Survived-leaf ratio was highest in BPSS and lowest in FLPN causing a little water leak on a rainy day. Rusty-root ratio was also highest in FLPN because soil moisture content was increased by water leak. The order of root yield was BPSS > APSS > FLPN, and the cause of highest yield in BPSS was higher light-penetrated ratio during spring and fall season, higher survived-leaf ratio, and lower rusty-root ratio than that of APSS and FLPN. BPSS showed highest total ginsenoside content because of high light-penetrated ratio, blue light effect, and the difference in dry matter partitioning ratio such as low taproot ratio, and high lateral root ratio.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.246-253
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• 2012

Despite frequent freezing injury to tea trees due low temperature, drought, and strong wind during wintertime, no comprehensive measurements have been taken. We selected and examined 9 locations in Hwagae-myeon and 4 places in Agyang-myeon, Hadong-gun, Gyeonsanggnam-do where low temperature damage had occurred between December 2010 and February 2011. Our objective is to examine the effect of frost damage on the morphological symptom and harvest of a tea tree exposed to a constant low temperature environment during wintertime. The results of our analyses on meteorological environment, tea leaf chromaticity, water content and trypan blue are as follows: (1) the number of days with temperature of $-10^{\circ}C$ or less, which were subject to frost damage to a tea tree were 8 and 13.6% during the winterization period in 2011; (2) the accumulated time was 1,308 minutes, and the longest duration at $-10^{\circ}C$ was 588 minutes from 21:08 p.m. 15 January to 7:30 a.m. $16^{th}$ January. The rainfall was only 104 mm which was 306 mm less than the previous year; (3) the lightness L values in 2011 were higher than in 2012 due to dehydration and necrosis by blue discoloration and red discoloration at all areas in chromaticity measurement; (4) the water content in a tea leaf in 2011 was higher than in 2012 due to low rainfall and strong wind, and almost no cell death phenomenon was observed from normal tea leaves subject to no low temperature stress in a trypan blue analysis; and (5) partial coloration due to cell death, however, took place in the leaves damaged by blue discoloration subject to low temperature stress, and most coloration due to cell death took place in the leaves damaged by red discoloration.

• Journal of Environmental Science International
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• v.25 no.5
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• pp.625-633
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• 2016

This study was conducted to investigate the influence of hydrophilic polymer (HP) mixture ratio (Control, 1.0%, 2.5%, 5.0%, and 10.0%) on growth of eggplant (Solanum melongena) for lower maintenance urban agriculture via green roofs. Although it was not statistically significant (p > 0.05), substrate temperature was decreased as hydrophilic polymer mixture ratio were increased. High substrate water content (95%) was found consistently in growing media under elevated hydrophilic polymer mixture ratio at over 5% during the entire growing period. Substrate electronic conductivity was increased as hydrophilic polymer mixture ratio were increased. Growth index was decreased as hydrophilic polymer mixture ratio was increased. It was reduced about 1/3 and 1/5 compared to that of Control in HP5.0 and HP10.0 treatment plants, respectively. Number of leaves, leaf length, and leaf width were decreased in following order: Control> HP1.0> HP2.5> HP5.0> HP10.0 treatments. There numbers were significantly lower in HP5.0 and HP10.0 treatment plants. Dry weight of shoot and root were decreased as hydrophilic polymer mixture ratio was increased. They were reduced by 1/4 compared to those of Control treatment plants. In addition, visual value was decreased as hydrophilic polymer mixture ratio was increased. Plants grown in HP1.0, HP2.5, and HP5.0 treatments all survived. However, plants grown in the HP10.0 treatment had the lowest survival rate (56%) after 3 months of growing. These results indicate that the advantage of adding hydrophilic polymer to green roof growing media may greater during dry periods. However, the proper mixture proportion of hydrophilic polymer should be determined according to different characteristics of growing media and plant species.

• The Korean Journal of Ecology
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• v.26 no.1
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• pp.5-12
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• 2003

Seed germination rate and seedling growth were measured on 6 different species(Phytolacca americana, Eupatorium rugosum, Rumex acetocella, Echinochloa crusgalli, Cassia mimosoides var. nomame, Setaria viridis) treated with leaf extract of E. rugosum. Total phenolic compound and heavy metal were analyzed on leaf and soil with and without E. rugosum. The growth of P. americana seedlings were stimulated by 10% and 25% of E. rugosum water extract treatment. The content of total phenolic compounds in soil was lower than that of leaf extract, and 25% was confirmed as threshold concentration in natural systems because the total phenolic compounds were not significantly different between the control soils and the soil treated with 10%, and 25% extract. Total phenolic compound concentrations of the leaf extracts were highest (1.66 mg/l) with E. rugosum grown under the Quercus forest canopy and lowest (1.09 mg/l) for the plant grown in the mixed forest edge. Leaf extracts of plants selected in different sampling sites (Forest interior, Forest edge, under Pinus Canopy and Quercus Canopy) were significant, while soil extracts were not. Seed germination of R. acetocella and S. viridis were significantly inhibited at over 50% concentrations of E. rugosum, but C. mimosoides var. nomame was not affected at any concentration. The radicle and shoot growth of the native species group were reduced two times more than those of the exotic species group by the treatment of extracts. Especially, the seed germination percentage and dry weight of E. rugosum were greater than those of the control group by treatments with extracts of 10% and 25%. Analysis of aqueous extracts from E. rugosum by HPLC identified 6 phenolic compounds: caffeic acid (460.9 mg/l), benzoic acid (109.7 mg/l), protocatechuic acid (7.3 mg/l), ρ-hydroquinone (6.0 mg/l), cinnamic acid (2.7 mg/l) and hydroquinone (0.23 mg/l). The seed germination of P. americana was also inhibited dramatically by protocatechuic acid and cinnamic acid even though the content of caffeic acid (460.9 mg/l) was the highest among analyzed phenolic compounds. The heavy metal content of soil without A. altissima was higher than that of soil with E. rugosum. Particularly, Al, Fe and Mn was considerably high and most of the heavy metal were accumulated in leaves where a high level of total phenolic compounds was found.