• Korean journal of applied entomology
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• v.47 no.4
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• pp.359-364
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• 2008

The development of Aulacorthum solani (Kaltenbach) was studied at temperatures ranging from 12.5 to $27.5^{\circ}C$ under $65{\pm}5%$ RH, and a photoperiod of 16:8 (L:D). Mortality of $1st{\sim}2nd$ nymph was higher than that of $3rd{\sim}4th$ nymph at the most temperature ranges whereas at high temperature of $27.5^{\circ}C$, more $3{\sim}4th$ nymph stage individuals died. The total developmental time ranged from 16.9 days at $12.5^{\circ}C$ to 6.6days at $22.5^{\circ}C$, suggesting that higher the temperature, faster the development. However, at higher temperature of $25^{\circ}C$ the development took 7.4 days. The lower developmental threshold temperature and effective accumulative temperatures for the total immature stage were $0.08^{\circ}C$ and 162.8 day-degreeslated development. The nonlinear shape of temperature rewas well described by the modified Sharpe and DeMichele model. When the normalized cumulative frequency distributions of developmental times for each life stage were fitted to the three-parameter Weibull function, attendance of shortened developmental times was apparent with in $1{\sim}2nd$ nymph, $3{\sim}4th$ nymph, and total nymph stages in descending order. The coefficient of determination $r^2$ ranged between 0.86 and 0.91.

• Korean journal of food and cookery science
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• v.15 no.1
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• pp.16-22
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• 1999

The relation between food intakes and dental caries was investigated with 211 primary school students (83 boys and 128 girls) in Kumsan area. The results were as follows. The rate of dental caries of the subjects was 65.4%. 83.9% of the subjects had a snack, 69.5% of students having a snack and 44.1% of students having not snack was dental caries (p<0.001). For tooth brushing numbers per day, 38.4% of subjects was one time, and 61.6% was more than two times. For tooth brushing time, 31.8% had before meals and 68.2% after meals. The intake frequency rate of main food was cooked rice 33.30%, ramyun 14.81%, bread 9.57%, rice cake 6.16%, nodule 4.88% in good group, and cooked rice 27.04%, rice cake 12.04%, ramyun 8.50%, bread 8.11%, fried rice 5.49% in dental caries group. The intake frequency rate of a side dish was kimchi 13.88%, egg 6.21%, dried laver 5.51%, fish paste 5.51%, fish 5.03%, kongjaban 0.44% in good group, and potato soup 6.86%, cucumber 6.56%, sprout soup 5.78%, bean curd 5.33%, sesame leaf 5.21%, lettuce 1.23% in dental caries group. The intake frequency rate for snack was ice cream 9.85%, biscuit 7.35%, gum 6.17%, chestnut 6.16%, apple 5.81%, milk 5.56%, yogurt 4.86%, gypo 4.39%, candy 4.15%, chocolete 3.91% in good group, and biscuit 10.00%, ice cream 6.75%, candy 5.88%, fruit canned food 5.70%, milk 5.41%, corn 5.00%, banana 5.00%, peanut 4.42%, fritter 4.39% in dental caries group. The rate of cariogenic food, detergent food, protective food in a side dish were 4.0%, 40.8%, 55.1%o in good group, and 11.5%, 43.9%, 44.6% in dental group respectively (p<0.001). The rate of cariogenic food, detergent food, protective food in a snack 67.8%, 10.4%, 21.7% in good caries group, and 75.3%, 8.8%, 15.9% in dental caries group respectively (p＜0.001).

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.225-233
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• 1991

This study was conducted to evaluate the potential of indigenous vesicular-arbuscular mycorrhizal fungi(VAMF) in the rhizosphere soil of horticultural crops grown under greenhouse and open-field condition, in the southern area of Kores. Soil samples collected from the rhizosphere of some sellected horticultural crops, such as cucumber, hot pepper, lettuca, tomato and eggplant grown under greenhouse or open-field condition. All tested crops are considered as mycorrhizal plants. The infection rate of horticultural crops investigated ranged from 38% to 70%, hot pepper and eggplant grown under greenhouse condition showed the highest infection being 66.0% and 70.0%, respectively. Spore densities were from 4.8 to 20.0g-1 on dried soil basis. Spore densities of VAMF in the rhizosphere soils under greenhouse condition were higher than that of open-field conditions. The highest distribution of spores in diameter ranged from $75{\mu}m$ to $106{\mu}m$ in the rhizosphere soil of lettuce, cucumber and tomato while those in hot pepper and eggplant ranged from $75{\mu}m$ to $250{\mu}m$. Glomus sp.-type spores predominated in the slightly acid soil(pH 6.3), while Acaulospora sp.-type spores greatly predominated in the very strongly acid field(pH 4.9).

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.350-355
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• 1995

This study was conducted to use oyster shells, which have caused environmental problems in the coastal of Korea, as an agricultural material after processing. Physico-chemical components and neutralizing amount on the Ihyun silt loam of crushed oyster shell and slaked lime were examined. In field experiment, the properties of the soil, growth and yield of lettuce, cabbage, spinach, onion, red pepper and soybean were examined by the treatments of the shell(3.68ton/ha) or the lime (2.76ton/ha) with a randomized block design. Particle size of crushed oyster shell consisted of 73.4% of 1~60mesh and 26.6% larger then 61 mesh and contents of CaO, OM, and $P_2O_5$, etc. were 55.5%, 1.3%, and 0.29%, respectively. The requirement of the shell to neutralize the soil was 130~135% of the lime, but after 24months, it was the same. The application of the shell increased the contents of available $P_2O_5$ and $SiO_2$ exchangeable Ca in used soil. The shell tratment increased the leaf height, leaf width, etc. of the examined plants, and the yields 6~154% according to examined plants, as compared with the nonliminged, indicating that the shell possesses a great potential as an agricultural material with the same effectiveness as the lime.

• Korean Journal of Weed Science
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• v.4 no.1
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• pp.69-78
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• 1984

This study was conducted to select herbicides effective for upland crops and to investigate the cause of crop injury in peanut cultivated with mulching. Crop such as radish (Raphanus acanthiformis Moor.), Chinese cabbage (Brassica raps L.), soybean (Glycine max Merr.), Peanut (Archis hypogaea L.), and marsh mallow (Malva olitoria Nakai) were tolerant to napropamide [2-(${\alpha}$-naphthoxy)-N, N-diethylpropionamide], alachlor [2-chloro-2', 6'-diethyl-N-(methoxymethyl) acetanilide], trifluralin (${\alpha},{\alpha},{\alpha}$-trifluoro-2, 6-dinitro-N, N-dipropylp-toluidine) and nitrofen (2,4-dichlorophenyl-p-nitrophenylether). Napropamide, diphenamide (N, N-dimethyl-2, 2-diphenylacetamide) and alachlor were safe for red pepper (Capsicum annuum L.), eggplant (Solanum melongena L. and tomato (Lycopersicon esculentum Mill.), while trifluralin, nitrofen and chlonitrofen (2,4,6-trichlorophenyl-4-nitrophenyl ether) could be used for water melon (Citrullus battich Forsk.), carrot (Daucus carota L.) and lettuce (Lactuca scariola L.) without crop injury. Out of nine major weed species studied, Capsella bursa-pastoris Medicus was the most resistant species to the herbicides tested. Napropamide and alachlor could not control P. hydropiper, while P. oleracea and C. album were tolerant to diphenamide :and alachlor, respectively. Urea herbicides such as methabenzthiazuron [3-(2-benzothiazolyl)-1,3-dimethylurea], linuron [3-(3, 4-dichlorophenyl~l-methoxy-i-methyl urea], and isoproturon [3-(4-isopropylphenyl) -1, 1-dimethylurea]gave a great injury to the crops studied. The weeding effect was greater for broadleaf weeds than for grasses. Isoproturon and linuron provided good selectivity for marsh mallow and carrot, respectively. In peanut, the crop injury caused by Four herbicides studied was greater when cultivated with mulching than when cultivated without mulching. With dinitroaniline herbicides the crop injury decreased as the gaseous herbicide was removed out of mulching. Alachlor gave little phytotoxicity to peanut grown under mulching condition and nitralin [4-(methylsuphonyl)-2, 6-dinitro-N, N-dipropylaniline] showed less toxicity to the peanut than pendimenthalin (3,4-dimethyl-2, 6-dinitro-N-1-ethyl propylaniline) and trifluralin.

• Korean Journal of Medicinal Crop Science
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• v.1 no.1
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• pp.3-9
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• 1993

This experiment was conducted to study germination characteristics and the decrease cause of germination percent in Angelica gigas Nakai seed. The emergence percent of winter sowing was higher than that of spring sowing as 66.6% and 41.1%, respectively, and the first emergence date was also earlier in winter sowing. The seed germination speed, percent and coefficent showed the highest value at $20^{\circ}C$ of incubation temperature, but lower value at $10^{\circ}C\;and\;30^{\circ}C$. The water uptake speed was increased along with increasing water temperature. The weight of imbibed seed at germination was 3.4times higher based on the weight of intact dry seed and 2.3times on removal of seed coat. In terms of length of seed was large, the germination percent was higher. The germination percent of brown colored seeds showed higher value than that of green colored seeds. The prolonged storage period decreased germination percent. When A.gigas seeds stored at room temperatue for 2years, the seeds were lost their viability. The biological inhibition effect of methanol, water and ether extract on the germination and growth of A.gigas and lettuce seed showed the highest value in the methanol extract, followed by water extract and the least in ether extract.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.238-246
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• 1994

Rate of conventional allpication of chemical fertilizer and farm manure were surveyed for 23 crops and 13,259 farms on paddy and upland fields in 1992. 1. Farmers have applied fertilizers more than optimum levels on vagetable crops. Based on the optimum levels of N, P and K, the excess ratios of N, P, K fertilization were 40%, 138%, and 53% in vagetable crops and 38%, 7%, and 0% in field crops, respectively. 2. Among provinces, the fertilizer application for paddy rice was higher in Chung-nam and Jeon-buk, which have had higher yield compared to other provinces. And that for red pepper was higher in Kang-won, Jeon-nam, Jeon-buk, Kyeong-nam, Kyeong-buk, and for chinese cabbage in Kang-won and Chung-nam. 3. The fertilizers rates at a chief producing districts of crops(CPD) were higher in vagetable crops than in field crops. 4. Compared with total fertilizer levels of open culture, excess fertilizers in plastic house were 5.9kg/10a(21%) of nitrogen, 8.7kg/10a(52%) of phosphorus and 7.1kg/10a(34%) of potasium. In chemical fertilizer application, fertilizer levels of sweet corn, red papper, tomato and lettuce were higher in plastic house, while those of cucumber, strawberry, radish, chinese cabbage were higher in open culture. 5. Ratio of farmers who applied farm manures was below 60 % on field crops and 69~100% on vagetable crops. 6. The compound fertilizer for paddy rice(21-17-17) was applied on all the crops and its application rate was the highest in all the crops except for paddy rice(single cropping), malting barley, soybean, sesame.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1230-1236
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• 2012

To verify that the electrokinetic remediation is effective for decreasing salinity of fields of the plastic-film house, field tests for physical property, chemical property, and crop productivity of soils have been conducted. The abridged result of those tests is as follows. In the EK treatment, the electrokinetic remediation has been treated at the constant voltage (about 0.8 V $cm^{-1}$) for fields of the farm household. At this time, an alternating current (AC) 220 V of the farm household was transformed a direct current. The HSCI (High Silicon Cast Iron) that the length of the stick for a cation is 20cm, and the Fe Plate for an anion have been spread out on the ground. As the PVC pipe that is 10 cm in diameter was laid in the bottom of soils, cations descend on the cathode were discharged together. For soil physical properties according to the EK treatment, the destruction effect of soil aggregate was large, and the infiltration rate of water was increased. However, variations of bulk density and porosity were not considerable. Meanwhile, in chemical properties of soils, principal ions of such as EC, $NO_3{^-}$-N, $K^+$, and $Na^+$ were better rapidly reduced in the EK treated control plot than in the untreated control plot. And properties such as pH, $P_2O_5$ and $Ca^{2+}$ had a small impact on the EK. For cropping season of crop cultivation according to the EK treatment, decreasing rates of chemical properties of soils were as follows; $NO_3{^-}$-N 78.3% > $K^+$ 72.3% > EC 71.6% $$\geq_-$$ $Na^+$ 71.5% > $Mg^{2+}$ 36.8%. As results of comparing the experimental plot that EK was treated before crop cultivation with it that EK was treated during crop cultivation, the decreasing effect of chemical properties was higher in the case that EK was treated during crop cultivation. After the EK treatment, treatment effects were distinct for $NO_3{^-}$-N and EC that a decrease of nutrients is clear. However, because the lasting effect of decreasing salinity were not distinct for the single EK treatment, fertilization for soil testing was desirable carrying on testing for chemical properties of soils after EK treatments more than two times. In the growth of cabbages according to the EK treatment, the rate of yield increase was 225.5% for the primary treatment, 181.0% for the secondary treatment, and 124.2% for third treatment compared with the untreated control plot. The yield was increased by a factor of 130.0% for the hot pepper at the primary treatment (Apr. 2011), 248.1% for the lettuce at the secondary treatment (Nov.2011), and 125.4% for the young radish at the third treatment (Jul. 2012). In conclusion, the effect of yield increase was accepted officially for all announced crops.

• Korean Journal of Environmental Agriculture
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• v.5 no.2
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• pp.141-148
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• 1986

The blue-light effect on the grown as well as on the physiological activity of some major horticultural plants in Korea has been investigated. The light quality used for the work was obtained from sunlight filtered by an orangecolored polyethylene film which removed about 70% of visible light in the spectral region of $350㎚{\sim}500㎚$. The film was developed in this laboratory especially for the work and named BCR film meaning blue color-removing film. The light environment in the plastic house which was built with BCR film provided plants with the blue color-deficient sunlight. Thus, the photobiological effect of blue light could be examined conversely by comparing with the effect of white sunlight in a conventional plastic house built with colorless polyethylene film. In a sense of applicability to horticulture, two remarkable effects of the blue color-deficient sunlight on plant physiology were observed: First, it enhanced to a great extent the growth activity of plants-pepper, cucumber, zucchini, tomato, and leaf lettuce at the vegetative stage as well as at the reproductive stage, as demonstrated by their yield which were in average $40{\sim}50%$ increased compared with the control (under white sunlight). Second, it improved significantly the cold tolerance of plants, as exhibited with their resistance to chilling during treatment in a cold chamber maintained at a temperature which caused chilling injury to the plants of control. The visualized effects were reflected on the physiological activity of cells on organelle level. Chloroplast isolated from the plant leaves grown under BCR film showed considerably stronger photosynthetic activity, as judged by the increased electron transport rate of illuminated chloroplast, than that from leaves grown under white PE film. Mitochondria from leaves grown under BCR film maintained normal respiration activity until temperature decreased to a few degree($^{\circ}C$) lower than the temperature which caused respiratory inhibition to mitochondria obtained from leaves of the control.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.289-295
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• 1993

The present paper was investigated in the inhibitory action of vegetable and seaweed water-soluble extracts on the formation of carcinogenic N-nitrosodimethylamine(NDMA). The vegetable and seaweed extracts obtained from garlic(Allium sativum), onion(Allium cepa), green onion(Allium fistuiosum), chinese pepper(Fagara mandshurica), green pepper(Capsicum annuum), red pepper(Capsicum annuum), ginger(Zingiber officinale), carrot(Daucus carota), laver(Porphyra tenera), sea lettuce(Entero compresa), sea mustard(Undaria pinnatifida) and sea staghorn(Codium fragile) were incubated with sodium nitrite-dimethylamine mixtures at $37^{\circ}C$ under different pH conditions The formation of NDMA was reduced to $10{\sim}40\%\;and\;25{\sim}50\%$ by the addition of vegetable and seaweed extracts 30mg at pH 1.2, respectively. The inhibition degree by the extracts at pH 1.2 was similiar to that at pH 4.2 and to that by ascorbic acid at pH 1.2. The inhibitory action of the extracts against NDMA formation was not decreased by heat treatment at $80^{\circ}C$ for 10min, but decreased by the treatment of sodium borohydride. It is assumed that reducing powers of the extracts participated in their inhibitory actions.