• Journal of the Korean association of regional geographers
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• v.2 no.2
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• pp.49-73
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• 1996

This study produces quantitatively weather entropy and information ratio using information theory about frequency in the appearance of precipitation phenomenon and monthly change, and then applies them to observation of the change of their space scale by time. As a result of these, this study defines Pusan, Chongju and Kwangju's weather representativeness and then establishes the range of weather representativeness. Based on weather entropy (statistical parameter)-the amount of average weather information-and information ratio, we can define each area's weather representativeness, which can show us more constant form included topographical, geographical factors and season change. The data used for this study are the daily precipitotion and cloudiness during the recent five years($1990{\sim}1994$) at the 69 stations in Korea. It is divided into class of no precipitation, that of precipitation. The results of this study can be summarized as follows: (1) The four season's mean value of information ratio is the highest value. as 0.641, on the basis of Chongju. It is the lowest as 0.572, on the basis of Pusan. On a seasonal basis, the highest mean value of information rate is April's (spring) in Chongju, and the lowest is October's(fall) in Pusan. Accordingly weather representativeness has the highest in Chongju and the lowest in Pusan. (2) To synthesize information ratio of decaying tendancy and half-decay distance, Chonju's weather representativeness has the highest in April, July and October. And kwangju has the highest value in January and the lowest in April and July. Pusan's weather representativeness is not high, that of Pusan's October is the lowest in the year. (3) If we establish the weather representative character on the basis of Chongju-Pusan, the domain of Chongju area is larger than that of Pusan area in October, July and April in order. But Pusan's is larger than Chongju's in January. In the case of Chongju and Kwangju, the domain of Chongju area is larger than that of Kwangju in October, July and April in order, but it is less than that of Kwangju area in January. In the case of Kwangju-Pusan, the domain of Kwangju is larger than that of Pusan in October, July in order. But in April it is less than Pusan's.

• Applied Biological Chemistry
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• v.24 no.1
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• pp.50-58
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• 1981

The influence of high temperature storage on the chemical composition and color intensity of the concentrated red ginseng extract(RGE) was investigated. The concentrated RGE was prepared by extraction of red ginseng tails with water and concentrated under reduced pressure. Changes in free sugars, saponin patterns and brown color intensity were measured during 96 hours of heat treatment at various temperature. A decrease in the contents of glucose, fructose and sucrose was resulted as the brown color intensity increased during the storage. The sugar contents and color intensity showed rapid initial change followed by slowing down at higher temperature. A significant relationship was found between sugar content and browning rate. The saponin pattern measured by high performance liquid chromatography, particularly in the region of protopanaxtriol, was also affected significantly. The peak heights of ginsenoside -Re and $-Rg_1$ were decreased while those of ginsenoside $-Rg_2$ and -Rh group were increased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.4
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• pp.334-341
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• 1984

Yield response of 30 rice varieties widely grown during the past 70 years in Korea was examined at the six transplanting dates from May 10 to June 29 at the 10 day intervals in 1982. Early japonica varieties grown before 1960s showed the highest yield at the June 9 and 19 transplantings and yields decreased with earlier or later transplantings except the earliest transplanting of May 10. However, yield of recent japonica varieties grown after 1960s was similar among the transplanting dates from May 10 to June 19, but yield was lower at the June 29 transplanting. In the indica/japonica varieties grown after mid- 1970s, yield was highest at the May 10, 20, and 30 transplantings and it decreased with further delay of transplantings largely due to the decreased panicle number, percent ripened grains, and 1,000 grain weight. This may indicate that recently developed varieties may be more adaptable toearly transplanting than older varieties. The number of panicles per hill was variable among the transplanting dates in all varieties, but it decreased as transplanting dates delayed after June 9. In japonica varieties the number of spikelets per panicle, percent ripened grains, and 1,000 grain weight increased as transplanting was delayed. However, in indica/japonica varieties the number of spikelets per panicle was similar among the transplanting dates and percent ripened grains and 1,000 grain weight decreased as transplanting date was delayed after June 9. The percent ripened grains of japonica varieties decreased with increase in the number of spikelets per hill but increased as heading date delayed. However, in indica/japonica varieties the percent ripened grains was not affected by both the number of spikelets per hill and heading date except that of June 29 transplanting of which percent ripened grains was extremely low because of delayed heading although the number of spikelets per hill was low. Grain/Straw ratio was not affected by heading date in japonica varieties, but it decreased significantly as heading date was delayed in indica/japonica varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.5
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• pp.429-444
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• 1991

Cold stress influence plant growth through a wide range of growth characters. Adverse effects of low temperature to plant growth come from results of colligative and complex physiological responses to cold stress. To evaluate more exactly cold tolerance of crop plant, it is needed to observe physiological changes induced by cold stress and to analyze relationships between intraspecific variations in physiological factors related to cold tolerance and the extent of cold tolerance in the field. Therefore, the composition and unsaturation ratio of fatty acids in phospholipid, a constituent of membrane, the transition-temperature in respiratory activity of mitochodria, the chlorophyll fluorescence as a factor related to photosynthesis were investigated in rice plant and data on these factors were compared with the degree of cold tolerance obtained in the field experiment. Also, effects of hardening and Mn++ treatment were evaluated as a method to reduce chilling injuries. The unsaturation ratio of fatty acids, whether rice plants were grown in a natural condition or under the chilling stress, was higher in the cold- tolerant varieties and was significantly correlated with the degree of cold tolerance (1-9) observed in the field experiment. And it was also increased by chilling treatment or hardening treatment, due to a reduction in palmitic acid content and an increase in linolenic acid content. The transition-temperature of respiratory activity of mitochodria isolated from etiolated rice seedlings ($25^{\circ}C$, two week-grown in the dark), was correlated with the degree of cold tolerance in the field, cold -tolerant varieties showing a lower transition-temperature. It was not influenced by growth stages. The intensity of chlorophyll fluorescence was highly correlated with the degree of cold tolerance, cold-tolerant varieties having a higher fluorescence intensity. By foliar application of Mn, the transition-temperature of respiratory activity was lowered as much as 0-2$^{\circ}C$ in all tested varieties. Soil application of Mn induced more significant effect in cold-susceptible varieties with a possibility of reducing chilling injuries. On the whole, there were high correlationships among the degree of cold tolerance, the unsaturation ratio of fatty acids in phospholipid, the transition- temperature of respiratory activity and chlorophyll fluorescence except for a few varieties. The transition- temperature of respiratory activity appeared to be negatively correlated with the unsaturation ratio of fatty acids. and the chlorophyll fluorescence to be positively correlated with the unsaturation ratio. This implies that these physical and physiological factors were very closely related to cold tolerance and can be used as an effective index of the evaluation of cold tolerance of crop plant. But other factors as well as three factors discussed above are needed to be considered colligatively and altogether with a systematic analysis for the more exact evaluation of cold tolerance. in rice cultivars. in rice cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.345-350
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• 1991

Rough rice samples of Chucheongbyeo, Bongkwangbyeo and Hwaseongbyeo were collected by the National Agricultural Products Inspection Office. Drying methods of rough rice were sun drying and forced ventilation drying by an oven dryer and temperature of the oven dryer was set to 43, 60, 70, or 8$0^{\circ}C$. Moisture content of samples was reduced from ca. 20% to 15% at the end of drying, and additionally to 12.5 % for the drying at 8$0^{\circ}C$. Characteristics related to rice grain quality, milling recovery, ratio of broken and cracked rices, percentage of germination, and sensory scores of the cooked rices were evaluated. Yielding percentage of brown rice and polished rice remarkably decreased by drying at 8$0^{\circ}C$. Percentages of cracked rice and broken rice were within the criterion of the second grade government brown rice (20%) only in the sun dried and the rices dried at 43$^{\circ}C$, on the basis of damaged rice, opaque kernel rice and colored rice. Broken rice percentage of the polished rice was within the criterion for the standard of government rice (5%) in the sun dried and the rices dried at 43$^{\circ}C$. Germination percentage of rough rice was higher than 80% in sun drying and drying at 43$^{\circ}C$, but remarkably decreased by drying rice at 6$0^{\circ}C$ and over. Sensory palatability of the cooked rice decreased with increase in drying temperature. The present governmental method of judging rough rice on the basis of moisture content and appearance of the rough rice appears to be improved to include the ratio of broken and cracked rices.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.6
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• pp.369-377
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• 2005

Precise application of topdressing nitrogen (N) fertilizer is indispensible for securing high yield and good quality of rice and minimizing N losses to the environment as well. For precise N management, growth and nitrogen nutrition status (NNS) should be diagnosed rapidly and accurately. The objective of the study was to evaluate the applicability of vegetation index (VI) calculated from hyperspectral canopy reflectance measurement and SPAD reading to nondestructive in situ diagnosis of growth and NNS of rice. Canopy reflectance, SPAD read­ing, growth parameters, and NNS characteristics were measured from various N treatments to evaluate the relationships among them for two cropping seasons from 2001 to 2002. The correlation coefficient of VIs with variables of growth and NNS increased positively as rice canopy became more closed. Regardless of growth stages, VIs had significantly high correlations with LAI, shoot dry weight (DW), shoot N content and nitrogen nutrition index (NNI). Those correlation coefficients increased steadily before heading stage as rice grew up. However, tiller number and leaf N concentration showed significantly high correlations with VIs only at and after panicle initiation stage (PIS). Among the VIs, RVIgreen had significantly higher correlation with the measured parameters than the other VIs: it showed correlation coefficients greater than 0.8 with leaf and shoot N concentration and DW, and much higher coefficients greater than 0.9 with LAI, shoot N content, and NNI. At LAI of below 2.5, VIs had non-significant or low correlations with the growth and NNS indicators due to the background effects. SPAD reading had significantly high correlation with leaf N concentration and NNI at each growth stage. In addition, it had significant correlations with variables of growth and NNS at PIS and booting stage, particularly, at booting stage. Though SPAD reading had a significantly high correlation value at a given growth stage in each year, it showed very weak relationship with variables of growth and NNS when pooled across growth stages and years. In conclusion, RVIgreen was found to be the most reliable VI to estimate the growth and NNS of rice around at PIS, but SPAD reading had much limitations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.484-490
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• 2015

Thirty-eight Pea (Pisum sativum L.) genotypes were screened to identify varieties to be suitable for sprout. Based on seed yield and sprout qualities such as whole length and sprout yield, five genotypes (PI269803, PI343278, PI343283, PI343300 and PI 343307) were primarily selected as candidates for pea sprouts. In order to determine optimal cultivation condition for pea sprouting, growth characteristics were investigated according to the change of germination temperature and days for sprouting. Whole length and hypocotyl length were observed to increase as a time dependent manner at each tested temperature (20, 23, and $25^{\circ}C$). However, whole length, hypocotyl length, and sprout yield were highly increased at $23^{\circ}C$ compared to 20 and $25^{\circ}C$. Especially, PI269803 and PI343300 showed higher sprout yield than the others. In addition, the effect of the change of germination temperature on antioxidant properties was estimated by measuring total phenolic content (TPC) and free radical scavenging activity (DPPH and ABST activity). TPC and DPPH/ABST activities of PI269803 and PI343300 were higher at $23^{\circ}C$ than at 20 and $25^{\circ}C$, while antioxidant properties of PI343278 and PI343283 were decreased in a temperature-dependent manner. The results show a high degree of correlation between TPC and antioxidant activities and suggest that the temperature change for pea sprouting could be responsible for antioxidant properties. Taken together, these results provide optimal cultivation conditions for pea sprouting and suggest that PI269803 and PI343300 with high sprout yield and antioxidant properties could be used for pea sprouts.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.9-16
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• 2016

To investigate the effect of soluble silicate zeolite dressing of the rice against bakanae disease, field trial in reclaimed land and in vitro were carried out. The coated rice seeds (SCS) which were dressed with the mixture of 25% silicic acids (binder), and the zeolite (coating powder). In wet direct seeding, uniform scattering of rice seeds on the soil surface and the better seedling establishment were shown in SCS treatment plots. The incidence of bakanae disease began from the mid tillering stage toward the heading stage. Around heading stage, the ratio of infected tillers reached its highest point by 9.9% in non-SCS treatment plots. While, in SCS treatment plots, the ratio of infected tillers was no more than 0.01%. The vitality of the pathogenic fungi of bakanae disease in the SCS and non-SCS samples were assessed. Samples were incubated for one week keeping proper humidity at $30^{\circ}C$ after inoculated with panicles of infected rice plants from experimental field plots. In non-SCS treatment, pinkish colonies were formed on the grain surface of panicle of infected plants, and mycelium, macro-conidia and micro-conidia were developed actively inside part of infected grain inoculated. While in SCS treatment, micro-conidia and mycelium were not survived and the growth of macro-conidia, mycelia were greatly inhibited and withered. Based on the results, it is concluded that the environmental friendly control of bakanae disease by use of SCS is possible and soluble silicate can be applied as agents for replacement of seed disinfection.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.1
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• pp.1-7
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• 2011

In this study, we investigated the antioxidant activities, inhibition activity against ACE (angiotensin converting enzyme) and antitumor activity of extract from Acanthopanax senticosus HARMS fruits for development novel functional resources. In order to understand the factors responsible for the potent antioxidant and antihypertensive ability of fruits in A. senticosus, it has been evaluated for anti-oxidative activity using Fenton's reagent/ethyl linoleate system and for free radical scavenging activity using the l,l-diphenyl-2-picryl hydrazyl free radical generating system. The fruits extract of A. senticosus showed higher antioxidant activities than positive control, ${\alpha}$-tocopherol at all concentrations, while fruits extract of A. senticosus showed same degree of radical scavenging activity with positive control, ${\alpha}$-tocopherol. The ability of fruit extracts from A. senticosus to influence the inhibitory activity of angiotensin converting enzyme (ACE) and xanthine oxidase (XOase) has also been discussed. The activity of growth-inhibitory of fruit extracts of A. senticosus was screened by SRB (sulphorhodamine B) method on diverse cancer cells representing different types of cancers. The fruit extracts of A. senticosus showed moderate inhibition on proliferation of LNCaP and MOLT-4F cells and did not inhibit the proliferation of other cancer cells. The fruit extracts of A. senticosus inhibited the proliferation of cancer cells with $GI_{50}$ values ranging from 5 to $10{\mu}g/mL$. This result revealed that the fruit extracts of A. senticosus was expected to be good candidate for development into source of free radical scavengers, antihypertentive, and anti-tumor agent.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.146-150
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• 2011

A large amount of nitrogenous compounds are found in burley tobacco and are responsible for peculiar aroma during smoking. Excess in nitrogen or its compounds such as total nitrogen and proteins in burley tobacco gives a strong pungency and make its taste bad. The present study has focused on improving quality of Burley tobacco by regulating topping and harvesting time of leaf to reduce nitrogen compounds in Burley tobacco. In addition, the early-stage of flower topping had lower level of nitrogenous compound, such as total nitrogen and protein nitrogen, and total tobacco-specific nitrosamine (TSNA) contents compared to the button-stage and full flower-stage topping. Also, the contents of nicotine got significantly decreased while the ether extract was increased as the period of topping got delayed. Regarding the brightness among the colors of cured leaves, the color at the full flower-stage topping was the brightest, and there was no particular difference in red and yellow colors. The harvesting amount was decreased as the period of topping got delayed and there was no significant difference between the topping treatments in terms of the exterior quality. As the harvesting time delayed, the total nitrogen, protein nitrogen, nitrate nitrogen, and ammonium nitrogen were decreased while the nicotine contents got increased. Also, the total TSNA contents were decreased as the harvesting time delayed. However, ether extract was increased. Among the colors of cured leaves, the brightness and degree of yellow color were significantly increased as the harvesting time delayed, and there was no particular difference in the degree of red color. The harvesting amount was decreased along with the delayed harvesting time; however, the harvest of the matured and mellow leaves was higher in terms of price, compared to that of the immature leaves. For the reduction of nitrogenous compound and TSNA contents in Burley tobacco, the topping was examined to be more effective in terms of improvement in chemical contents and quality regardless of the decreased harvesting amount.