• Korean Journal of Soil Science and Fertilizer
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• v.6 no.2
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• pp.107-113
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• 1973

A pot experiment on paddy rice was carried out to investigate the effect of temperature after heading with application of phosphate, potash and silica on the yield and nutrient uptake. The results obtained are as follows: 1. The Grain yield was greatly affected by temperature during ripening. The yield at $20^{\circ}C$ and at $15^{\circ}C$ decreased to 62.3% and to 37.2% of that at $25^{\circ}C$ respectively. However, the application of phosphate, potash and silica at transplanting increased the grain yield even at low temperature of $15^{\circ}C$. 2. Percentage of ripened grain and weight of 1,000 grains decreased with decreasing temperature but they were increased by the application of phosphate, potash and silica at the low temperature of $15^{\circ}C$. 3. The grain filling rate was fast in the early stage of ripening at high temperature while it was fast in the later stage at low temperature. Low temperature damage was severe in the early stage of ripening. 4. Accumulation of carbohydrate in the grain was small at low temperature of $15^{\circ}C$ and the application of phosphate, potash and silica was effective to increase carbohydrate content in the grain at low temperature. 5. The content of T-N and $P_2O_5$ in straw grown at low temperature were high whereaas those of $K_2O$ and $SiO_2$ were low which were increased by the application of potash and silica. 6. There was a positive correlation between the grain yield and rate of ripening, 1,000 grain weight, contents of $K_2O$ and $SiO_2$, $K_2O/N$ and $SiO_2/N$ ratio, but a negative correlation between grain yield and contents of T-N and $P_2O_5$ in the straw at harvesting stage. 7. Ripening rate and weight of 1,000 grains showed a significant positive correlation with $K_2O$, $SiO_2$, $K_2O/N$ and $SiO_2/N$ ratio in the straw. Further, there was a negative correlation between ripening rate and the contents of T-N and $P_2O_5$ but a positive correlation between weight of 1,000 grains and these elements.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.4
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• pp.232-242
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• 2002

To investigate the effects of arbuscular mycorrhizal (AM) fungus (Glomus intraradices) colonization on drought-stress tolerance, leaf water potential, chlorophyll concentration, P content and carbohydrate composition were examined in perennial ryegrass (Lolium perenne L.) plants exposed to drought-stressed or well-watered conditions. Drought stress significantly decreased leaf water potential, P content and leaf growth. These drought-induced damages were moderated by mycorrhizal colonization. Drought stress decreased the concentration of soluble sugars in shoots. AM plants had a higher foliar soluble sugar than non-AM plants under drought stress condition. Drought stress depressed the accumulation of starch and fructan in shoots, but stimulated in roots. Under drought-stressed condition, starch concentration in roots was higher in non-AM plants than in AM plants. Fructan was the largest pool of carbohydrates, showing the highest initial concentration and the highest net increase for 28 days of treatment. Drought stress slightly decreased fructan concentration in shoots, but remarkably increased in roots. Under drought-stressed condition, fructan concentrations in non-AM and AM shoots at day 28 were 18.7% and 13.3% lower than the corresponding values measured at well-watered plants. However, in the roots, fructan accumulation caused by drought was lessen 13.6% by mycorrhizal colonization. The results obtained suggest that mycorrhizal colonization improves drought tolerance of the host plants by maintaining higher leaf water status and P status, and by retaining more foliar soluble sugars.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.44-54
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• 2018

To maintain the best quality of kimchi during long-term storage, we developed a fermentation storage mode for the kimchi refrigerator. The optimal kimchi fermentation temperature was determined to be $6^{\circ}C$ with fermentation time of 4-7 days in winter and 3-5 days in spring and fall. Based on these results, the fermentation storage mode conditions were programmed to consist of a fermentation temperature of $6^{\circ}C$ and fermentation times of 111 h in winter and 58 h in spring/fall. When kimchi was stored under the developed fermentation storage mode conditions, the total acidity of kimchi was almost the same as that of the control kimchi (stored $-2-\;-1^{\circ}C$ for 12 weeks). However, the number of lactic acid bacteria (LAB) and Leuconostoc sp. in kimchi were higher ($10^1-10^2CFU/mL$) than those in the control kimchi during storage. In addition, kimchi fermented and stored under the fermentation storage mode clearly received higher scores for overall preference than the control kimchi.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.73-80
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• 2011

To investigate the characteristics of plant growth and flower quality of gerbera 'Sunny Lemon' by amount of nutrient solution, young seedling plants, 'Sunny Lemon' were transplanted to rock-wool and medium of peat moss and perlite mixed with 1 to 2 and they were acclimatized in greenhouse during about 1 month. Nutrient solution supplied to the plants is sonneveld solution of 1/2 concentration and treatments launched June 24, 2010 when average plant height was $20{\pm}1cm$. Nutrient contents as a standard for starting point of irrigation by time domain reflectometry (TDR) were determined with 60-65%, 70-75%, and 80-85%. Results of growth during vegetative growth, plant height, leaf width and leaf number increased by 10% in rockwool, but they were not significantly different. As for plant growth depending on nutrient content, 80-85% treatment showed the highest values. Leaf number increased by 60%, and leaf width and plant height had a about 40% increase than initial growth. Effectiveness for flower quality, yield and days to flowering were superior when nutrient content of media was higher than in the others. Especially, average days to flowering in 80-85% content was advanced by 7-10 days compared to the day in 60-65% treatment. The total amount of nutrient supply per plant was higher in mixed medium than in rockwool, but change patterns of EC and pH were enhanced in rockwool. Based on our results, we recommended that growth, cut flower, and yield of gerbera 'Sunny Lemon' were more effective when nutrient content of mixed medium was maintained at 80-85%.

• FLOWER RESEARCH JOURNAL
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• v.16 no.1
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• pp.36-43
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• 2008

This purpose of this study was to examine the effect of planting density, growing medium and strength of a nutrient solution (National Horticultural Research Institute's nutrient solution: HRI's) on the growth and development of Oriental hybrid lily 'Le Reve' in a box cultivation. The planting density with 14, 18 and 22 bulbs had sprouting one day earlier than other treatments. Planting density of 22 bulbs flowered first, while six bulbs flowered the last, indicating that higher planting densities led earlier flowering. The increasing planting density increased stem length of cut flowers. On the other hand, cut flower quality was improved when the planting density was lower. The incidence of physiological disorders such as blasting was more frequent in planting density of 22, 18, and 14, indicating that higher planting densities caused higher incidences of physiological disorders. All planting densities except 22 bulbs displayed superior results in width, weight, number, and scale weight of the bulbs. Greater planting densities led to inferior bulb enlargement and an increased decomposition rate. pH decreased in all treatments after the bulb enlargement and decreased more as the planting density increased. Contents of P, K, Ca, and Mg increased, while contents of K and Ca decreased, as the planting density increased. The rice hull+coir (1:1, v/v) treatment was better than others, but did not show that much of a difference. Moreover, in bulbs enlargement after cut flower harvest, lily medium and perlite+peat moss treatments showed superior results, and decomposition rate was the greatest in the rice hull+coir (1:1, v/v) treatment. In the HRI's solution strength treatment from the period of flower bud emergence to flower harvest, higher solution strengths gave better cut flower quality in terns of length, weight, and number of flowers. The non-treated control and one third strength of a HRI's solution hastened flowering, indicating that lower strengths led to earlier flowering. According to the results of leaf analysis as affected by solution strength during the flower harvest, absorption rates of N and K were greater when the strength was higher, and Ca and Mg showed the same tendency. On the other hand, the absorption rate of P was the lowest in all treatments.

• Food Science and Preservation
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• v.15 no.5
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• pp.760-768
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• 2008

The present study investigated the effect of Leuconostoc kimchii GJ2 (Leu. kimchii GJ2), an exopolysaccharide-producing lactic acid bacterium isolated from kimchi, on serum and liver lipid metabolism in rats fed a high-cholesterol diet. Male Sprague-Dawley rats were divided into four groups: a normal diet group (ND), a high-cholesterol diet group (HCD), a high-cholesterol diet and 200 mg/kg Leu. kimchii GJ2-administered group (HCD-LKL), and a high-cholesterol diet and 400 mg/kg Leu. kimchii GJ2-administered group (HCD-LKH). No between-group differences were found in body weight gain, food intake, or food efficiency ratio. The serum GOT and ALP activities that were elevated by the high-cholesterol diet were significantly decreased after Leu. kimchii GJ2 administration. Serum HDL-cholesterol level was markedly increased in the Leu. kimchii GJ2-administered groups, whereas the serum total cholesterol and LDL-cholesterol levels were lower in the Leu. kimchii GJ2-administered animals. Liver levels of total cholesterol and triglyceride were also markedly lower in the Leu. kimchii GJ2-administered groups. In addition, increased activities of HR-LPL and TE-LPL in adipose tissue, caused by the high-cholesterol diet, fell to normal after administration of Leu. kimchii GJ2, in a dose-dependant manner. These results suggest that Leu. kimchii GJ2 isolated from kimchi exerts an antiatherosclerotic effect by reducing serum and liver cholesterol levels.

• Food Science and Preservation
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• v.17 no.5
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• pp.688-697
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• 2010

We investigated the cholesterol-lowering and body-weight loss effects of Cheonggukjang fermented using Bacillus subtilis DJI in rats fed a high-fat/high-cholesterol diet for 4 weeks. Weight-matched male Sprague-Dawley rats were assigned to one of four groups: a normal diet group (N), a high-fat/high-cholesterol diet group (HFC), a high-fat/high-cholesterol diet with DJI Cheonggukjang group (HFC-SCK), and a high-fat/high-cholesterol with commercial Cheonggukjang group (HFC-CCK). All of body weight and liver and adipose tissue weights increased in animals fed a high-fat/high-cholesterol diet, but decreased significantly in rats fed Cheonggukjang powder, compared with the HFC group. Food intake was lower in the HFC group than in the N group, and that of the HFC-CCK group was the lowest among the four groups. Serum total cholesterol levels were significantly lower in the Cheonggukjang-powder fed groups than the other groups. Serum phospholipid and HDL-cholesterol concentrations were significantly decreased in HFC animals and were markedly increased upon feeding of a Cheonggukjang-containing-diet. Levels of serum LDL-cholesterol, the atherogenic index, and cardiac risk factor assessment indications tended to be decreased in Cheonggukjang powder-fed groups, compared with the HFC group. The total cholesterol level in liver tissue was increased by feeding of a high-fat/high-cholesterol diet, and was significantly reduced when Cheonggukjang powder was present in the diet. The levels of total lipids and triglycerides in adipose tissues were lower in the HFC-SCK group than in the HFC group, whereas no significant differences were evidence when the HFC and the HFC-CCK groups were compared. Fecal weight, moisture level, and total lipid content increased in animals fed Cheonggukjang powder. The activities of HR-LPL and TE-LPL in adipose tissues were increased in the HFC group compared with the Cheonggukjang powder-fed groups. These results indicate that dietary Cheonggukjang may improve lipid metabolism and prevent obesity and hyperlipidemia.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.1
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• pp.16-24
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• 1998

To determine the optimum application of fertilizers for the cultivation of Chinese cabbage in plastic film house, twenty soils which contain different salts contents were taken from 4 different area of plastic film house cultivation, Youngdong. Boeun county, Cheongweon county, and Cheongju city. The dry weight and the amount of N. P, and K uptakes of Chinese cabbage in the plot of no fertilization were considered as the factors representing the fertility of the soil. And a difference of dry weight and the amounts of N, P, and K uptakes of plants between the plot of fertilization and no fertilization were considered as the factors representing the total effect of fertilizer and fertilizer N, P, and K effects. respectively. These factors of soil fertility and fertilizer effects were estimated by correlation and regression with soil tests in order to find the critical levels and recommended method for optimum fertilization of Chinese cabbage. Chinese cabbage transplanted in two soils, having the electrical conductivity of 9.3 and 15.2 dS/m, were not able to root due to the salts toxicity. The content of inorganic N, the electrical conductivity, and CEC were founded to have significant correlation with the factors of both the soil fertility and fertilizer effects for the cultivation of Chinese cabbage. To determine the weighting degree for the productivity and the fertilizer effects, the standardized partial regression coefficient was analyzed by regression among the factors of fertility, the fertilizer effects, and the soil tests. The coefficient for inorganic N($NH_4-N$ and $NO_3-N$) was obtained as the absolute value of 756-1871 and this value was extremely higher than those of other soil tests which was 0.07-4.11. These results suggested that the content of inorganic N is the best tests for the estimation of the productivity and the fertilizer effects for the cultivation of Chinese cabbage in plastic film house. The critical level of inorganic N($NH_4-N+NO_3-N$) estimated by Cate-Nelson split method for maximum productivity and zero point of fertilizer effect was 220 mg/kg for all the factors of estimation. These results suggested that no application of fertilizer N. P, and K is required at the critical level of inorganic N of soil. Consequently the optimum application of fertilizer N, P, and K for the cultivation of Chinese cabbage in plastic film house was possible to determine by the critical level of inorganic N of soil. The critical level of electrical conductivity was estimated as 2.8 dS/m by the same method.

• Korean Journal of Organic Agriculture
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• v.29 no.2
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• pp.223-240
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• 2021

This study was carried out to investigate the economic value of organic wheat production using gelatin·chitin microorganisms in Gwangsan-gu, Gwangju city. The soil condition of experiment field was clay loam Jisan series. The organically cultivated fields were sprayed gelatin and chitin degrading bacteria. The test was performed at conventionally cultivated field and organically cultivated field. Emergence of weed on organically cultivated field was significantly higher than conventionally cultivated field which sprayed herbicide before seeding. Weed emergence have a critical impact on grain yield. Occurrence of diseases and insect pests were higher than conventionally cultivated fields. In 2019, the amount of lodging in conventionally cultivated field were higher than conventionally cultivated field. In 2020, lodging and wet injury were occur in both field. Comparing yield element between organically and conventionally cultivated experimental area, grain yield in organically cultivated field was shown slightly higher amount than conventionally cultivated field. However in the actual yield of 2019, organically cultivated field shows 20% deceased yield because of overgrown weed. In 2020, weed emergence and yellow mosaic virus by wet injury cause 30% decease in the grain yield in organically cultivated field. Content of protein, carbohydrates, ash, water and fat in the grain were not different significance. In 2019, net incomes of conventionally cultivated wheat was 461,031 won/0.1 ha while organically cultivated wheat was 443,437 won/0.1 ha. In the rate of income, conventionally cultivated field was 83.0% as against organically cultivated field (73.3%). In 2020, net incomes of organically cultivated wheat was 437,812 won/0.1 ha while conventionally cultivated wheat was 418,281 won/0.1 ha. In the rate of income, conventionally cultivated field was 81.6% as against organically cultivated field (73.0%).

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.581-586
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• 2011

'Cheongdam' is a japonica rice variety developed from a cross between SR19200-HB826-34, a line of good germination ability and shoot emergence at low temperature and Juanbyeo, good quality and direct-seeding adaptable cultivar by the rice breeding team of National Institute of Crop Science, RDA in 2006. This variety has 153 days of total growth duration from seeding to maturity in direct-seeding, and 160 days of growth duration from seeding to maturity in transplanting. This is erect plant type with culm length of 74 cm, thick culm, and green leaves. It has large panicle shape with 126 and 140 spikelets per panicle in direct-seeding and transplanting, respectively. Milled rice is transluscent and medium in grain size of non-glutinous endosperm. This variety is susceptible to leaf and neck blast, bacterial blight, stripe virus disease and brown planthopper. The yield potential of 'Cheongdam' is 5.84 MT/ha at ordinary transplanting culture and 5.62 MT/ha and 5.89 MT/ha at wet direct-seeding and dry direct-seeding cultures, respectively in the local adaptability test for three years. 'Cheongdam' would be adaptable to middle and southern plain of Korea for direct-seeding culture and transplanting rice culture.