• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.440-446
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• 1986

The physiological reaction of two soybean (Glycine max (L.) Merrill) cultivars tolerant and susceptible to rust (Phakopsora pachyrhizi Syd.) was studied at the AVRDC in Taiwan, ROC. The rust epidemic on the susceptible cultivar began earlier and progressed more rapidly than on the tolerant cultivar. The defoliation by rust infection increased rapidly after the latter half of pod filling. The reduction of LA! by rust in the susceptible cultivar occurred earlier than in the tolerant cultivar. The differences in the chlorophyll content between the rust-free and rust-infected plants was 2.04% in the tolerant, and 16.43% in the susceptible cultivar. The shoot dry weight increased at each growth stage in the fungicide protected plots, but decreased in the non-fungicide protected plots after the R6 growth stage onward and the tendency to decrease was more severe in the susceptible than in the tolerant cultivar. The pod and seed dry weight of the suscep-tible cultivar in the fungicide-protected plot increased dramatically from the R6 growth stage, but in the non-fungicide plot, there was almost no increase in pod and seed dry weight from R6 growth stage, due to rust. The number of empty pods and imperfect grains were increased by rust infection, but the protein content was not afftected. There were reductions of oil content, seed length, seed width, seed thickness, pod thickness, number of pods and seeds, 100 seed weight, and yield due to rust infection. The yield losses by rust infection were 22.3%in the tolerant and 68.7% in the susceptible cultivar.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.254-259
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• 1998

This study was focused on finding out the potential problems associated with organic farming system. The effect of composted animal manures subsequent inoculation of microbes on growth and yield of tomatoes (Lycopersicon esculentum Mill. 'Minicarol') were examined to develop a proper organic farming practice. Plant heights were greater in composted manure treatment than in conventional practice, whereas widths of leaves were higher in conventional field. Chlorophyll contents between various amount of composted manure application were gradually decreased and showed no significant differences after 45 days of planting. The yield in the treatment applied 12 ton of composted animal manure per 10a as pre-planting fertilizer and following microbial inoculation were only 50-60% compared to that of conventional farming. However, yield increased up to 80% when additional composts were applied to the treatment received 6 ton of composted animal manure per 10a in the middle of cultivation. Microbial inoculation followed by composted manure application induced rapid decrease of nitrogen content in soil. However, the density of microorganisms was significantly increased. Tomatoes produced through organic farming were clear in color, Further, soluble solid and acid content were increased. The highest level of acid and solids were observed in the treatment applied 12 ton of digested swine manure per 10a. Although nitrogen content including ammonium and nitrate rapidly increased after application of composts, these were significantly reduced approximately 4-5 weeks after planting. The level of phosphorus, potassium, magnesium and calcium showed gradual decrease compared to nitrogen.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.4
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• pp.73-85
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• 1991

Rhododendron mucronulatum for. albiflorum, native species is a shrub that has white flowers on May to June, and rare species endangered by people's rash digging or cutting. But its physiological ecological characteristics and propagation method are not being known at all. Therefore, this study was executed to utilize this species as the planting material for landscaping by analysing its habitat environment and growth form, and also experimenting its seed and vegetative propagation, and it field culture and utilization. The results are as follows; 1. The elevation, gradient and direction of this species were 295-1,350m, 10-36$^{\circ}$, northwest respectively. It was found that the species is shade-liking plant that grows under forest cover of average 51.33%. 2. The soil pH and water content of its habitat were 5.4, 25.41% respectively. The organic matter content was 6.29% that was higher than 3.2%, the average organic matter content of forest soil in Korea. 3. Representative plant community within which this species was living was Quercus mongolica community, and its main neighboring species were Lindea obtusiloba, Fraxinus sieboldiana, Rhus trichocarpa, Rhododendron Schlippenbachii, Rododendron mucronulatum. 4. The leaf length and width of this species were 39.18mm, 12.60mm respectively. This result showed that generally its leaf size was larger than that of R. micranthum, R. yedoense var. poukhanense and R. mucronulatum var. ciliatum and smaller than that of R. mucronulatum and R. schlippenbachii. 5. The whole size of its pollen was, as 59${\times}$61$\mu\textrm{m}$, the largest of plants of Rhododendron family including R. mucronulatum and R. mucronulatum var. ciliatum. 6. The result of seed germination experiment at intervals of 5$^{\circ}C$ from 15$^{\circ}C$ to 30$^{\circ}C$ presented the highest germination rate of 94.7% at 20$^{\circ}C$ numerically, but high percent germination at all temperature levels without significant difference. And the seed of this plant proved to be sun-liking seed at requiring dormancy in germination. 7. Through seed germination experiment by treatment of growth regulators such as GA. Thiourea and Kinetin under dark condition, it was found that the effect of GA treatment on germination increase and acceleration was the highest. 8. In greenwood cutting, rooted rate by treatment of various concentration of IBA and NAA on clay and vermiculite bed was not wholly high, but 100ppm plots of both IBA and NAA of clay bed showed relatively good rooted rate. 9. As result of field culture experiment for finding out optimum growth temperature and light intensity, growth conditions such as height, number of leaves, fresh weight and chlorophyll contents were the best at night/day temperature of 20/25$^{\circ}C$ and under 1/2sun. Also, the photosynthetic rate was the highest at 25$^{\circ}C$. Accordingly, it was found that optimum temperature and light intensity for growth of this plant are 25$^{\circ}C$ (day temperature), 50% of natural light respectively.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.150-159
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• 1996

This study was conducted to investigate the inhibition of protox activity and the PPIX accumulation of the oxyfluorfen-tolerant and-susceptible rice cultivars with barnyardgrass, a typical susceptible weed in accordance by oxyfluorfen treatment. The susceptible rice cultivars and barnyardgrass showed more inhibition of protox activity due to the treatment of oxyfluorfen than the tolerant rice cultivars. Especially in the concentration at $10^{-6}$M treatment, protox activity of the susceptible rice cultivars and barnyardgrass were the completely inhibited but the tolerant rice cultivars kept 32~59% of activity compared to the control. As the treatment concentration increased, the content of PPIX accumulation increased and it increased untill four hours of light exposure but it tended to decrease these after. The content of PPIX accumulation by the treatment of oxyfluorfen was more pronounced in the light condition than in the dark. Under the light and dark conditions, the susceptible rice cultivars and barnyardgrass showed more PPIX accumulation than the tolerant rice cultivate. Especialiy the susceptible barnyardgrass had more than the rice. With the treatment of GC and DA, tetrapyrrole biosynthesis inhibitor, the herbicidal activity by oxyfluorfen was inhibited, and the susceptible rice cultivars and barnyardgrass tended to have less effective than the tolerant rice cultivars and the content of chlorophyll or PPS accumulation tended to be similar.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.372-378
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• 2007

This study was carried out to investigate the effect of potassium concentrations in fertigation solution on growth and development of nutrient deficiency symptoms of leaf perilla (Perilla frutesens). The nutrient concentrations in above ground plant tissue, petiole sap and soil solution of root media were also determined. Potassium deficiency symptoms developed in older leaves with marginal necrosis. The brown areas on the lower leaves enlarged rapidly and the margins became scorched. Elevation of K concentrations in the fertigation solution up to 8 mM increased the crop growth in leaf length, stem thickness, and fresh and dry matter production of above ground plant tissue. However, that decreased the chlorophyll contents. The 8.0 mM K treatment which showed the greatest growth had 5.01 g in dry weight and 2.76% in K content of above ground plant tissue, suggesting that maintaining K content higher than 1.7% is necessary for good growth of Perilla frutesens. The K concentrations in petiole sap and soil solution of 8.0 mM treatment were $12,289mg{\cdot}kg^{-1}\;and\;11.65mg{\cdot}L^{-1}$, respectively. These indicated that K fertilization to maintain higher than $8,700mg{\cdot}kg^{-1}$ in petiole sap and $4.5mg{\cdot}L^{-1}$ in soil solution are necessary to ensure good crop growth.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.764-772
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• 2018

It is necessary to explore the possibility of alternative habitats and research the characteristics of basic habitats due to seeding, culturing and harvesting of blood clams (Tegillarca granosa) in tidal flats. Currently, dependence on naturally occurring spat is much higher than in other species, which may lead to a reduction in biological resources. In this study, we selected a total of 5 sites (Changgi, Hopo in Cheonsu Bay and Dangsan, Sachang, Wangsan in Garolim Bay) and examined habitat suitability factors for suitable site selection. Also, we considered the relationship of habitat suitability factors (Environment: water content, organic content; survival: mud content, mean size; growth: chlorophyll a). As a result, Wangsan had the highest score of the main habitat of blood clams (Habitat suitability score, Wangsan: 87; Dangsan: 86; Sachang: 81; Hopo: 78; and Changgi: 73). The sediment in Garolim Bay was fine-grained and the seasonal variation was lower than Cheonsu Bay. Therefore, it is considered that Garolim Bay is more suitable as a potential area and easy to utilize the space. In the future, search and selection of potential suitable sites could be considered to solve problems caused by the reduction of biological resources and the production for blood clams.

• Korean Journal of Medicinal Crop Science
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• v.9 no.1
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• pp.33-39
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• 2001

The split application of a nitrogen fertilizer was applied at the levels to 3, 4, 5, 6 and 7 time. The results of yield and quality of Okro tea are summarized as follows: Among five treatments, the growth and yield were somewhat more excellent in the five time split treatments compared with other treatments. The chemical components such as total nitrogen, total amino acid and vitamin C were somewhat higher in the five time split treatment compared with other treatment. However, the content of components such as tannin, caffeine, chlorophyll were not different among plots of $4{\sim}7$ time split application except three time split application manuring. The content of fatty acid was producted $2,888{\sim}2,933mg/100g$. Especially, the content of oleic acid, linoleic acid and linolenic acid was the higheat in the five time split application. Sixteen kinds of free amino acid including theanine as a good taste component of Okro tea were isolated and measured by HPLC. Theanine in the five time split application was higher with value of $72{\sim}513mg/100g$ than in other treatment. In scoring test, tea appearance and interal qualities of 3 time split application become lower than any other treatment as 80.2 point, while five time application had the highest with 84.7 point. Conquently, those results meant that five time split application was optimum split application of fertilizer for high yield and good quality of Okro tea.

• Korean Journal of Medicinal Crop Science
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• v.22 no.6
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• pp.469-474
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• 2014

This study was performed to investigate the effects of sowing density and number of seeds sown on the emergence rate and growth characters of Panax ginseng C. A. Meyer under direct sowing cultivation in a blue plastic greenhouse. Ginseng seedlings, derived from seeds sown directly at different densities (90, 108, 135, and 162 seeds per $162m^2$), were cultivated in sandy loam soil within a blue plastic greenhouse. In contrast to the emergence rate, which decreased with an increase of sowing density, number of survival plant showed an increasing trend. Interestingly, the emergence and number of survival plant were significantly enhanced when 2 or 3 seeds were sown per hole compared with when one seed was sown per hole. Growth of the aerial parts of ginseng were not markedly influenced by sowing density or the number of seeds sown. However, chlorophyll content (SPAD values) increased with an increase in sowing density. Root parameters, such as root length, diameter, and weight, and the number of lateral roots decreased with an increase in sowing density, but were not noticeably influenced by the number of seeds sown. Total saponin content was the highest in the treatment plot containing 135 seeds. Similarly, the content of each ginsenoside was also tended to be higher in this treatment than in other treatment plots. On the basis of the results obtained in this study, it was possible to determine the optimal sowing density and seed number for the direct sowing cultivation of ginseng in blue plastic greenhouse.

• Korean Journal of Environmental Agriculture
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• v.15 no.3
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• pp.335-340
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• 1996

A green house experiment was conducted to investigate the growth of Chinese cabbage, radish and soybean and change in the chemical properties of the soil after the 10mm application of the simulated acid rain(SAR) of pH 2.7 in the form of sprinkle and mist. It was applied 30 times for Chinese cabbage and radish and 62 times for soybean at the two-day intervals. The results obtained are summarized as follows: 1. Visual damages caused by SAR were dark-brown or red brown leaf spots in Chinese cabbage, and dark-brown and wrinkled leaf margins in radish and soybean. 2. The degree of visual damages became severer as the number of SAR applications increased and it was severer with mist than with sprinkle of SAR. 3. Chlorophyll content was reduced by SAR, but it was not affected by the form of SAR application(sprinkle or mist) in all crops, although it was slightly lower with mist than with sprinkle of SAR. 4. Fresh weight of Chinese cabbage heads and radish roots and grain yield of soybean were reduced by SAR, and were not affected by the form of SAR application. 5. Contents of K, Ca, and Mg in leaves were reduced, while S content increased by SAR in all crops. The forms of SAR application did not affect contents of mineral nutrients in all crops. 6. SAR decreased soil pH and the contents Ca, Mg, and K of soil, while increased $SO_4$ content. However, the contents of soil organic matter, N, and P were not affected by SAR. Forms of SAR application did not affect soil chemical properties either.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.628-632
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• 2013

Arthrospira platensis (A. platensis) is an economically important microalgae because it has carbohydrates, lipids, proteins and a number of phytochemicals. It is also a valuable source used in the production of biodiesel and functional foods. In this study, A. platensis was exposed to electron beam irradation (240 kGy) and induced random mutagenesis for strain improvement. Several mutants were obtained, and the resulting mutant was designated as EB29. The growth rate and chlorophyll content of EB29 was similar to those of wild type. However, the lipid content of EB29 was increased seven-fold compared to that of wild type when comparing the nile red fluorescent intensity. Semi-quantitative analysis of EB29 using the calibration plot of standard lipid, triolein, represented $78.6{\mu}g/mL$, which increased 2 times compared to wild type ($41.4{\mu}g/mL$). When analyzing the fatty acid profile of EB29, polyunsaturated fatty acids (PUFAs), such as gamma-linolenic acid (GLA) in EB29 increased about six-fold. Moreover, fatty acids affecting the quality of biodiesel increased compared to that of wild type. Thus, electron beam could be used for the strain improvement of microalgae in order to accumulate PUFAs and alteration of fatty acid profile for biodiesel.