• Horticultural Science & Technology
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• 제28권3호
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• pp.353-362
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• 2010

The contents of functional and nutritional components of 13 cultivars of Chinese cabbage (CC, $Brassica$ $rapa$ subspecies $campestris$) were analyzed to compare the effects of soil pH of the greenhouse (pH 6.2) and outdoor (pH 7.6). The CC cultivated on pH 6.2 (CC-6.2) soil contained significantly increased amounts (2-9 fold) of pectin, crude protein, vitamin C and vitamin E compared to the counterpart (CC-7.6). The contents of ash and the minerals (Ca, Fe, Na, and Mn) were also significantly increased in CC-6.2. However, CC-6.2 contained 40-50% lower contents of reducing sugars, cellulose and crude fat than CC-7.6. CC-7.6 contained more glucosinolates, gluconasturtiin (18.33 vs. $1.16nmol{\cdot}g^{-1}$ wet weight) and gluconapin (145 vs. $2nmol{\cdot}g^{-1}$ wet wt), than CC-6.2. In conclusion, CC-6.2 had an improved texture (high pectin and low cellulose) and nutritional value (high in protein, Ca, Fe, vitamin C, and E), whereas the CC-7.6 had better taste (high in reducing sugars) and anticancer functionality (high in glucosinolates).

• Asian Journal of Turfgrass Science
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• 제23권2호
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• pp.317-330
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• 2009

Research was initiated to investigate germination vigor, number of leaves, plant height and turfgrass density. A total of 18 treatment combinations were used in the study. Treatments were made of soil organic amendment(SOA), sand, and water-absorbing polymer. Germination vigor, leaf number, plant height and turfgrass density were evaluated in Kentucky bluegrass(KB) grown under greenhouse conditions. Significant differences were observed in germination vigor, leaf number, plant height and turfgrass density among 18 mixtures of SOA and polymer. Highest germination rate was associated with mixture of SOA 20% + sand 80% + polymer 0%, resulting in 56.3% for KB. Number of leaves at 60 DAS(days after seeding) were greater with KB over PR, while plant height higher with PR over KB. Leaf number increased with SOA, being SOA 20% > SOA 100% > SOA 10% and with polymer from 0 to 12%. Plant height was greatest with SOA 20% and lowest with SOA 100%. Greater density was observed with PR rather than KB due to longer plant height. Turf density was best under SOA 10% and poorest under SOA 100% in KB. A further research would be required for investigating the individual effect of K-SAM, Ca, perlite on the turf growth characteristics.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제42권1호
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• pp.68-78
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• 1997

Laboratory and greenhouse studies were conducted to determine differential sensitivities on absorption of $^{14}$ C-oxyfluorfen and the anatomical responses in wheat and barley to protoporphyrinogen oxidase-inhibiting herbicides [oxyfluorfen (2-chloro-1- (3-ethoxy -nitrophen-oxy)-4-(trifluoromethyl) benzene, acifluorfen(5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-nitro-benzoic acid), bifenox(methyl-5-(2, 4-dichlorophenoxy)-2-nitrobenzoate) and oxadiazon(5-tert-butyl-3-(2, 4-dichloro-5-isopropoxyphenyl)-1, 3, 4-oxadiazol-2-one)]. I$_{50}$ value of the tolerant wheat cultivars to oxyfluorfen was about 10$^{-4}$ , whereas that of the susceptible barley cultivars was about 10$^{-6}$ M, showing significant difference between the two groups. When foliage were applied with acifluorfen, bifenox or oxadiazon, the oxyfluorfen-tolerant wheat showed less decreased in shoot fresh weight and chlorophyll content than the susceptible barley. Also, when soil-applied with these herbicides test plants showed similar tendency in foliar application. Electrolyte leakage from the tissue treated with these compounds was the more influenced in the barley than the wheat. Malondialdehyde(MDA) production as index of lipid peroxidation was greater in the barley than the wheat by treatment of these compounds. Therefore, the differential sensitivities of wheat and barley to protoporphyrinogen oxidaseinhibiting herbicides was showed by our greenhouse and in vitro experiment. The absorption rates of $^{14}$ C-oxyfluorfen were higher in the barley than the wheat. And this tendency was showed appararitly difference by increase of treatment durations. After the oxfluorfen and oxadiazon treatment, the tolerant wheat did not show the structural damage in leaf surface, but the susceptible barley was damaged in the leaf waxy layer. However, the acifluorfen and bifenox treatment showed no difference between wheat and barley. The anatomical changes by these compounds treatment were not observed in the tolerant wheat but epidermal cell and mesophyll cell were highly broken in the susceptible barley.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제63권2호
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• pp.140-148
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• 2018

As the global warming causing desertification increase, there is growing concern about damage of crops. It was to investigate how the treatment with hydrogen peroxide before leaf development affects the growth and yield of sorghum for minimizing a damage of crops to drought. The germination experiment was conducted at alternating temperature of $25^{\circ}C/20^{\circ}C$(12 hr/12 hr) under water stress condition of 0 ~ -0.20 MPa adjusted with PEG solution containing 0 and 10 mM $H_2O_2$. In order to know the effect of foliar application of hydrogen peroxide on the growth of sorghum, 10 mM hydrogen peroxide was treated to leaves at 3-leaf stage of sorghum growing in greenhouse conditions. Seed germination rate was increased by 20% in hydrogen peroxide treatment as compared to the Control. under water stress conditions (-0.15 ~ -0.20 MPa). The length of seedlings was also on the rise by the hydrogen peroxide treatment. In the greenhouse pot experiment, the morphological characteristics (plant height, stem diameter, leaf length, and leaf number) and physiological characteristics (chlorophyll content, chlorophyll fluorescence (Fv/Fm), stomatal conductance) were higher in the plants treated with hydrogen peroxide under the drought stress condition than those of plants of $H_2O$ treatment. Experiment conducted with the soil moisture gradient system showed that the foliar application of hydrogen peroxide increased photosynthetic ability of sorghum plant with respect to SPAD value and stomatal conductance and rooting capacity (root weight and root length) under drought condition. Generally, hydrogen peroxide treatment in sorghum increased the tolerance to drought stress and maintained better growth due to ameliorating oxidative stress.

• Journal of Bio-Environment Control
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• 제18권1호
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• pp.29-39
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• 2009

The influence of windbreak to minimize the ventilation velocity near the plant canopy of a greenhouse strawberry was thoroughly investigated using computational fluid dynamics (CFD) technology. Windbreaks were constructed surrounding the plant canopy to control ventilation and maintain the concentration of the supplied $CO_2$ from the soil surface close to the strawberry plants. The influence of no windbreak, 0.15 m and 0.30 m height windbreaks with varied air velocity of 0.5, 1.0 and 1.5 m/s were simulated in the study. The concentrations of supplied $CO_2$ within the plant canopy of were measured. To simplify the model, plants were not included in the final model. Considering 1.0m/s wind velocity which is the normal wind velocity of greenhouses, the concentrations of $CO_2$ were approximately 420, 580 and 653 ppm ($1{\times}10^{-9}kg/m^3$) for no windbreak, 0.15 and 0.30 m windbreak height, respectively. Considering that the maximum concentration of $CO_2$ for the strawberry plants was around 600-800 ppm, the 0.30 m windbreak height is highly recommended. This study revealed that the windbreak was very effective in preserving $CO_2$ gas within the plant canopy. More so, the study also proved that the CFD technique can be used to determine the concentration of $CO_2$ within the plant canopy for the plants consumption at any designed condition. For an in-depth application of this study, the plants as well as the different conditions for $CO_2$ utilization, etc. should be considered.

• The Korean Journal of Pesticide Science
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• 제2권3호
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• pp.52-63
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• 1998

A novel quinolineoxadiazoles, substituted the carboxylic acid group with 1,2,4-oxadiazole radicle, of KSC-16960 and related compounds were evaluated to examine the herbicidal activity, crop injury and residual effect of after-vegetable crops compared with those of quinclorac (3,7-dichloro-8-quinolinecarboxylic acid), of which use is now banned because of its residual activity to some succeeding vegetable crops. KSC-16960 showed 2- and 3-leaf stages of barnyardgrasses effectively controlled by more than 95 and 90%, respectively, at a rate of 6.25 g/ha. The dose of KSC-16960 controlled 4- and 5-leaf stages of barnyardgrasses by more than 90% were found to be 50 g and 100 g/ha, respectively. The selectivity of KSC-16960 between direct-seeded rice and barnyardgrass was approximately 2-fold higher than that of quinclorac when they were treated to the soil. The selectivity indices of KSC-16960 and of quinclorac between 1-leaf stage of direct seeded rice and 5-leaf stage of barnyardgrass were 44 and 23, respectively, and those between 1-leaf stage of direct seeded rice and 4-leaf stage of barnyardgrass were almost 2-fold higher. Application of KSC-16960 with bentazone exhibited an additive controlling effect on several weed species, but that of quinclorac exhibited an antagonistic effect. With pyrazosulfuron-ethyl, on the other hand, both application of KSC-16960 and quinclorac showed additive interactions. Under a greenhouse condition, the residual activity of KSC-16960 to succeeding tomato plants was approximately 4-fold lower compared to that of quinclorac. KSC-16960 could be substituted for quinclorac, if it will be made some more improvement for reducing residual activity.

• Journal of Environmental Science International
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• 제22권2호
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• pp.139-149
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• 2013

Anthropogenic increases in greenhouse gas concentrations, primarily through radiative forcing from carbon dioxide, continue to challenge earth's climate. This study quantified $CO_2$ storage and uptake by dominant forest types and age classes in the middle region of Korea. In addition, the role of forest landscapes in reducing atmospheric $CO_2$ against $CO_2$ emissions based on energy consumption was evaluated. Mean $CO_2$ storage and uptake per unit area by woody plants for three forest types and four age classes were estimated applying regression equations derived to quantify $CO_2$ storage and uptake per tree; and computations per soil unit area were also performed. Total $CO_2$ storage and uptake by forest landscapes were estimated by extrapolating $CO_2$ storage and uptake per unit area. Results indicated mean $CO_2$ storage per unit area by woody plants and soils was higher in older age classes for the same forest types, and higher in broadleaved than coniferous forests for the same age classes, with the exception of age class II (11-20 years). $CO_2$ storage by broadleaved forests of age class V (41-50 years) averaged 662.0 t/ha (US$331.0 hundred/ha), highest for all forest types and age classes evaluated. Overall, an increased mean $CO_2$ uptake per unit area by woody plants was evident for older age classes for the same forest types. However, decreased $CO_2$ uptake by broadleaved forests at age class V was observed, compared to classes III and IV with an average of 27.9 t/ha/yr (US$14.0 hundred/ha/yr). Total $CO_2$ storage by woody plants and soils in the study area was equivalent to 3.4 times the annual $CO_2$ emissions, and woody plants annually offset the $CO_2$ emissions by 17.7%. The important roles of plants and soils were associated with 39.1% of total forest area in South Korea, and $CO_2$ emissions comprised 62.2% of the total population. Therefore, development of forest lands may change $CO_2$ sinks into sources. Forest landscape management strategies were explored to maintain or improve forest roles in reducing atmospheric $CO_2$ levels.

• Journal of Microbiology and Biotechnology
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• 제21권1호
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• pp.55-61
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• 2011

Forty yeast strains isolated from soils taken from different locations in Egypt were tested for their P-solubilizing activities on the basis of analyzing the clear zone around colonies growing on a tricalcium phosphate medium after incubation for 5 days at $25^{\circ}C$, denoted as the solubilization index (SI). Nine isolates that exhibited P-solubilization potential with an SI ranging from 1.19 to 2.76 were genetically characterized as five yeasts belonging to the genus Saccharomyces cerevisiae and four non-Saccharomyces, based on a PCR analysis of the ITS1-26S region amplied by SC1/SC2 species-specific primers. The highest P-solubilization efficiency was demonstrated by isolate PSY- 4, which was identified as Saccharomyces cerevisiae by a sequence analysis of the variable D1/D2 domain of the 26S rDNA. The effects of single and mixed inoculations with yeast PSY-4 and Bacillus polymyxa on the P-uptake and growth of corn were tested in a greenhouse experiment using different levels of a phosphorus chemical fertilizer (50, 100, and 200 kg/ha super phosphate 15.5% $P_2O_5$). The results showed that inoculating the corn with yeast PSY-4 or B. polymyxa caused significant increases in the shoot and root dry weights and P-uptake in the shoots and roots. The P-fertilization level also had a significant influence on the shoot and root dry weights and P-uptake in the shoots and roots when increasing the P-level from 50 up to 200 kg/ha. Dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 200 kg/ha gave higher values for the shoot and root dry weights and P-uptake in the shoots and roots, yet these increases were nonsignificant when compared with dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 100 kg/ha. The best increases were obtained from dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 100 kg/ha, which induced the following percentage increases in the shoot and root dry weights, and P-uptake in the shoots and roots; 16.22%, 46.92%, 10.09%, and 31.07%, respectively, when compared with the uninoculated control (fertilized with 100 kg/ha).

• Journal of Korean Society of Forest Science
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• 제85권3호
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• pp.524-531
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• 1996

The objective of this study was to determine the important factors affecting the early natural regeneration of Pinus densiflora S. et Z. Seed germination, survival and height growth of the pine seedlings were examined at four experimental plots of P. densiflora forests including forest roadside. Plots I and III were thinned in 1992, plot II was treated with hexazinone in 1993 after seed tree method was applied in 1982 and 1989. Seedlings emerged after thinning and the rate of their emergence depended on forest floor conditions. Seedling survival was related with light conditions, herbaceous vegetation, and degrees of rainfall. More seedlings emerged in forest hauling roads than within the forest because soil scarification due to logging provided better conditions for seed germination and seedling growth. Seed supply was enough, but germination rate was very low in the forest compared with that in the greenhouse because micro-environments such as organic layer and herbaceous plant acted as limiting factors. Weed control was needed for 4 to 5 years until seedlings grew upto about 50cm in height which was similar to that of herbaceous plants. But 10-40% coverage of herbaceous vegetation was needed to protect small seedlings from heavy rain. Forest works such as thinning and logging, over 40% of light were important factors to help the pine regeneration. However, over 70% coverage of herbaceous vegetation, and heavy rain inhibited rather survival and growth of pine seedlings.

• Korean Journal of Environmental Biology
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• 제35권1호
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• pp.13-20
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• 2017

Greenhouse gas emission from agricultural land is recognized as an important factor influencing climatic change. In this study, the national $CO_2$ emission was estimated for paddy soils, using soil GHG emission model (DNDC) with $1km^2$ scale. To evaluate the applicability of the model in Korea, verification was carried out based on field measurement data using a closed chamber. The total national $CO_2$ emission in 2015 was estimated at $5,314kt\;CO_2-eq$, with the emission per unit area ranging from $2.2{\sim}10.0t\;CO_2-eq\;ha^{-1}$. Geographically, the emission of Jeju province was particularly high, and the emission from the southern region was generally high. The result of the model verification analysis with the field data collected in this study (n=16) indicates that the relation between the field measurement and the model prediction was statistically similar (RMSE=22.2, ME=0.28, and $r^2=0.53$). More field measurements under various climate conditions, and subsequent model verification with extended data sets, are further required.