• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.349-353
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• 2007

To investigate the effect of NaCl concentration on plant growth in three halophytes, Suaeda asparagoides, Suaeda maritima, and Salicornia herbacea, and to select afforestation species for reclaimed land along the shore, this experiment was conducted by ebb and flow system added fertilize of 1/2 Hoagland solution and halophytes were cultured for 4 month treated by 0, 50, 200, 400 mM NaCl, respectively. The shoot height was increased with 0 and 50 mM NaCl treatment of Suaeda asparagoides and Suaeda maritima and decreased with 200, 400 mM NaCl treatment, whereas them of Salicornia herbacea was increased by 200 mM NaCl treatment. The higher NaCl concentrations, the lower fresh and dry weight in Suaeda asparagoides. In case Suaeda maritima and Salicornia herbacea, fresh and dry weight was increased by 200 mM NaCl treatment. The higher NaCl concentrations, the lower chlorophyll contents in shoot of all treatment. The proline contents of 400 mM treatment in Suaeda maritima was higher than them of other treatments. The shoot water potential was generally lower in 50mM as compared to the control in Suaeda asparagoides, Suaeda maritima, significantly.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1B
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• pp.101-105
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• 2010

Sunflower (Sunking4505) and Rape (Sunmang) are oil-seeds containing high oleic acid, and these are used for the production materials of bio-diesel and applying for phytoremediation. The effect of cadmium on germination rate and the growth of the plants is evaluated. Object seeds were placed in Cd (0, 1.5, 4, 12, 30, 60, 100, 150, 300, 500 mg/L) solutions for seven days, and germination rate, root length, shoot length, seedling length, and dry weight were observed. $IC_{50}$, seedling vigor index, and tolerance indices were computed, and data were statistically analyzed by Analysis of Variance (ANOVA). Germination rate as well as root, shoot, and seedling length decreased as the cadmium concentration increased except dry weight. The $IC_{50}$ of sunflower and rape are 112 and 10 mg-Cd/L, respectively. Only one of the sunflower seeds is germinated at 500 mg-Cd/L whereas rape seeds are not germinated more than 150 mg-Cd/L solution. Root has higher cadmium sensitivity than shoot, and sunflower has higher germination rate, growth, and seedling vigor index than rape. In case of tolerance indices, sunflower has lower value than rape at relatively low concentration, but has higher value at high concentration.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.4
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• pp.275-283
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• 2010

This experiment was conducted to construct process models to estimate grain weight (GW) and grain nitrogen content (GN) in rice. A model was developed to describe the dynamic pattern of GW and GN during grain-filling period considering their relationships with temperature, solar radiation and growth traits such as LAI, shoot dry-weight, shoot nitrogen content, grain number during grain filling. Firstly, maximum grain weight (GWmax) and maximum grain nitrogen content (GNmax) equation was formulated in relation to Accumulated effective temperature (AET) ${\times}$ Accumulated radiation (AR) using boundary line analysis. Secondly, GW and GN equation were created by relating the difference between GW and GWmax and the difference between GN and GNmax, respectively, with growth traits. Considering the statistics such as coefficient of determination and relative root mean square of error and number of predictor variables, appropriate models for GW and GN were selected. Model for GW includes GWmax determined by AET ${\times}$ AR, shoot dry weight and grain number per unit land area as predictor variables while model for GN includes GNmax determined by AET ${\times}$ AR, shoot N content and grain number per unit land area. These models could explain the variations of GW and GN caused not only by variations of temperature and solar radiation but also by variations of growth traits due to different sowing date, nitrogen fertilization amount and row spacing with relatively high accuracy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.1
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• pp.45-54
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• 2009

This experiment was conducted to clarify the effects of source and sink related characteristics on grain weight increase and grain nitrogen accumulation in rice. Source was modified by leaf removing treatment with no sink modification in 2002 and sink and source were modified at the same time by different sowing dates, N fertilization rates, row spacings, and thinning treatments at heading in 2007. Grain weight (GW) and grain assimilates produced by photosynthesis during grain-filling ($GW_P$) increased with the increase of source, while the grain assimilates retranslocated from leaf and stem ($GW_T$) decreased. Among the source-related characters, shoot dry weight were most closely related with GW. GW was dependant on $GW_P$ rather than on $GW_T$. Grain nitrogen content (GN) and grain nitrogen absorbed from soil during grain-filling ($GN_S$) increased with the increase of source, while the grain nitrogen retranslocated from leaf and stem ($GN_T$) decreased. Shoot nitrogen content among the source-related characters was related most closely with GN. The contribution of $GN_T$ to GN was relatively large although GN depended more largely on $GN_S$ than $GN_T$. In addition, GN was supplied firstly from $GN_S$ or from $GN_S$ and $GN_T$ at the same time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.599-607
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• 2006

The experiments were carried out to develop simulation model for estimating the yield of soybean in upland and paddy field condition. Field experiments were done at National Institute of Crop Science in 2005. The evaluated soybean cultivars were Taekwangkong, Daewonkong, and Hwangkeumkong. Soybean seeds were planted by hill seeding with 3-4 seeds and row and hill spacing were $60{\times}10cm$ in upland and $60{\times}15cm$ in paddy field. Seeds were sown on row (without making ridge) and on the top of ridge in upland and paddy field, respectively. Field parameters were measured yield components ($plants/m^{2}$, pod no./plant, and 100-seed weight, seed yield and growth characteristics (stem length, leaf area at each stage, and dry weight of shoot) and after measuring they were compared the relationships with seed yield and yield components and seed yield and growth characteristics. Seed yield of soybean was affected by cultivars and planting density. Seed yield was higher in upland than paddy field due to the higher planting density in upland field. The upland soybeans generally had lower 100-seed weight than that of paddy field. Seed yield of soybean in a paddy field was greatest in Taekwangkong and followed by Daewonkong and Hwangkeumkong. The harvest index of taekwangkong and Hwanggumkong was higher in upland than paddy field, however, it was higher in paddy field than upland in Daewonkong. Seed yield was greatest in Daewonkong in both experimental fields. The greatest stem length was observed in taekwangkong and Hwanggumkong (R6) in late growth stage in paddy field. Dry weight of shoot and pod, pod number, stem length, and stem diameter were higher grown in paddy field than grown in upland. Crop growth rate (CGR) of cultivars was higher in paddy field after 8 WAS(weeks after sowing) and it was greatest at 13 WAS in Daewonkong among the cultivars. In upland field, CGR was greatest in Taekwangkong and then followed by Daewonkong and Hwanggumkong during 12 and 15 WAS. There was no significant relationships between 100-seed weight and seed yield in both experimental fields. A significant positive relationship was observed between seed number and seed yield. The correlation coefficients between leaf area and shoot dry weight were about 0.8 during the whole growth stage except 5 WAS and 4-5 WAS in paddy field and upland, respectively. This experiment was done just one year and drained paddy field condition was not satisfied drained condition successfully at 7th leaf age of soybean by the heavy rain, so we suggest that the excessive soil water reduced seed yield in paddy field and the weather condition should be considered for utilizing of these results.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.236-242
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• 1996

Orostachys japonjcus, called Wasong in herb medicine, has been artificially cultivated as an anti-tumor medicinal. The experiment was done to examine the effect of night-break periods imposed immediately before its bolting time on its morphological, flowering-related characters and fraction dry weights. After a plant was grown in a 15cm plastic pot containing a 2:1 soil:Peat moss mixture for about 3 months, three different night-break periods (0.5, 1 and 2 hours) around midnight were treated from Aug. 24. to compare with the natural daylength. The plants were sampled 6 times by 2-week interval after the treatments. Plant height and inflorescence length of all the treatments inclined with time lapse after the treatment and were shorter in 2 hour night-break due to slow increment than in the other treatments, while stem diameter showed reverse result. All the treatments except 2 hour night -break were nearly same in fraction, shoot and total dry weights per plant; two hour night-break treatment had greater leaf and bract weight from 6 weeks, greater stem, shoot and total weights from 2 weeks and greater root weight from 4 weeks but did less floret weight after the treatment. Although florets on the inflorescence were formed in 2 hour night-break treatment, flowering florets and flowering plants never occurred. In the other treatments showed the similar response, however, more florets appeared from 2 weeks, flowering florets was sharply increased from 6 weeks and flowering plants were reached up to 100% from 6 to 8 weeks after the treatment. Inflorescence length or number of total florets per plant in 2 hour night-break was positive-correlated to all the fraction dry weights except that those of natural daylength was not done, meaning that its artificial cultivation should permit bolting to secure more shoot dry matter.

• FLOWER RESEARCH JOURNAL
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• v.19 no.1
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• pp.37-41
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• 2011

This experiment was carried out to find an optimum shading level for the growth of root and shoot, and to find the effect of shading level after August on the induction and growth of inflorescence of Phalaenopsis hybrid. The shading levels were 50%, 60%, 70%, 80% and 90% of natural light($1200{\mu}molm^{-2}s^{-1})$. The $CO_2$ uptake, transpiration rate, carbohydrate content, fresh weight and dry weight of Phalaenopsis hybrid were higher at 50-60% level than the others. But, it was diminished when the shading level was increased from 70% to 90%. Inflorescence length, the number of inflorescence and flower per plant all increased under 50-60% shading level and the day needed for the flowering after treatment decreased. Especially, the induction of inflorescence was depressed and flowering is not occurred under 90% during experiment period. These results suggest that the optimal shading level for the growth of Phalaenopsis including inflorescence was founded to be 50-60% in the season of light intensity and amount of sunshine decrease after august.

• Journal of Korean Society of Forest Science
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• v.99 no.5
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• pp.693-697
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• 2010

Biomass expansion factors that convert the timber volume (or dry weight) to biomass are used to estimate the forest biomass and account for the carbon budget on a national and regional scale. This study estimated the biomass conversion and expansion factors (BCEF), root to shoot ratio (R), biomass expansion factors (BEF) and ecosystem biomass expansion factor (EBEF) of Korean pine (Pinus koraiensis) forests based on direct field surveys and publications in Korea. The mean BCEF, BEF, and R was 0.6438 Mg $m^{-3}$ (n = 7, SD = 0.1286), 1.6380 (n = 27, SD = 0.1830), and 0.2653 (n = 14, SD = 0.0698), respectively. The mean EBEF, which is a simple method for estimating the understory biomass in Korean pine forest ecosystems, was 1.0218 (n = 6, SD = 0.0090). The values of the biomass expansion factors in this study estimated the Korean pine forest biomass with more precision than the default values given by the IPCC (2003, 2006).

• Journal of Ecology and Environment
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• v.35 no.2
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• pp.73-78
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• 2012

$Calotropis$ $procera$ L. is a perennial shrub distributed in saline areas of deserts of South Asia. Salt stress is a very challenging subject in arid and semi-arid areas. Germination stage is very sensitive and many plants do not germinate in saline soil. The objective of this study was identifying the salinity effect on seed germination of $Calotropis$ $procera$ L. The experimental design was a complete randomized block design with NaCl and $CaCl_2$ at five levels of isobar concentrations: 0.0, -0.01, -0.05, -0.1, and -0.15 MPa. Osmotic potential had significant effects ($P$ < 0.01) on germination percentage, germination rate, shoot length, root length, and seedling dry weight. All seedling characteristics decreased with decrease in osmotic potential. Shoot length and root length decreased more than the seedling characteristics. Germination was completely inhibited in -0.1 Mpa. Priming with NaCl and $CaCl_2$ (-0.1 MPa) for four days had significant effects ($P$ < 0.01) on the germination percentages. Priming improved the seedling characteristics in all samples, especially in -0.05 Mpa, but a decrease with decrease in osmotic potential.

• Korean Journal of Medicinal Crop Science
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• v.16 no.3
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• pp.144-149
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• 2008

Shoot weight of Orostachys japonicus should determine its profitability. The study was done to determine the effect of phosphorus and potassium fertilization (0, 5, 10, 20 kg $P_2O_5$ or $K_2O$ /1000 $m^2$) on its growth, morphological characters, and flowering. Night-break treatment of 2 hours at midnight were done since Aug. 25 when afterward samples were taken every 4 weeks to Nov. 16. Growth, morphological and flowering related characters were measured from each sample. Plant height, inflorescence length, number of leaves including bracts and stem diameter were increased with increased P and K levels. Leaf and bract, floret, shoot and total dry weights showed similar response to the above morphological characters although P fertilization more increased them than K fertilization. Florets were more formed with increased P and K levels but were not flowered due to the night-break treatment, meaning that P and K fertilization had little effect on anthesis of the florets formed.