• Journal of Bio-Environment Control
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• 제28권1호
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• pp.38-45
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• 2019

Recycling of drained nutrient solution in hydroponic cultivation of horticultural crops is important in the conservation of the water resources, reduction of production costs and prevention of environmental contamination. Objective of this research was to obtain the fundamental data for the development of a recirculation system of hydroponic solution in semi-forcing cultivation of 'Bonus' tomato. To achieve the objective, tomato plants were cultivated for 110 days and the contents of inorganic elements in plant, supplied and drained nutrient solution were analyzed when crop growth were in the flowering stage of 2nd to 8th fruiting nodes. The T-N content of the plants based on above-ground tissue were 4.1% at the flowering stage of 2nd fruiting nodes (just after transplanting), and gradually get lowered to 3.9% at the flowering stage of 8th fruiting nodes. The tissue P contents were also high in very early stage of growth and development and were maintained to similar contents in the flowering stage of 3rd to 7th fruiting nodes, but were lowed in 8th node stages. The tissue Ca, Mg and Na contents in early growth stages were lower than late growth stages and the contents showed tendencies to rise as plants grew. The concentration differences of supplied nutrient solution and drained solution in $NO_3-N$, P, K, Ca, and Mg were not significant until 5 weeks after transplanting, but the concentration of those elements in drained solution rose gradually and maintained higher than those in supplied solution. The concentrations of B, Fe, and Na in drained solution were slightly higher in the early stages of growth and development and were significantly higher in the mid to late stages of growth than those in supplied solution. The above results would be used as a fundamental data for the correction in the inorganic element concentrations of drained solution for semi-forcing hydroponic cultivation of tomato.

• Korean Journal of Breeding Science
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• 제50권4호
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• pp.442-452
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• 2018

In this study, we analyzed the growth characteristics and isoflavone content of 43 soybean varieties highly adaptable to highland areas. The flowering period of each cultivation zone was from July 15 to August 12 at Daewallyeong, from July 18 to August 11 at Jinbu, and from July 23 to August 13 at Gangneung. The accumulated temperature from flowering to maturity was $1,297^{\circ}C$ for Daegwallyeong, $1,391^{\circ}C$ for Jinbu, and $1,685^{\circ}C$ for Gangneung. Forty-three varieties were classified into four utilities; soy sauce and tofu, bean sprouts, cooking with rice, and vegetable and early maturity. The content of isoflavone was highest at $2,579{\mu}g/g$ in varieties for soy sauce and tofu usage. Five varieties ("Paldalkong," "Sinpaldal2," "Ilmikong," "Sinpaldalkong," and "Daepung") cultivated in Daegwallyeong had over $4,000{\mu}g/g$ of isoflavone. The isoflavone content of the region Daegwallyeong was different at the significance level of 0.1 (p=0.061) compared to Gangneung. There was no significant difference between Gangneung and Jinbu. It is thought that the low temperature of the maturation stage during the growing period affected isoflavone accumulation. The varieties with more than $3,000{\mu}g/g$ of isoflavone content in Daegwallyeong, Jindu, and Gangneung were "L29," "Williams82," "Ilmikong," and "Daepung." These were genetically and environmentally stable in isoflavone content. It is expected that this study will be used as basic data for the functional breeding and selection of soybean varieties highly adaptable to a specific region, and to help expand soybean cultivation areas in highlands.

• Korean Journal of Environment and Ecology
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• 제17권2호
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• pp.169-176
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• 2003

The genetic relationships between 4 Korean native Taraxacum and 2 naturalized Taraxacum species were analyzed using the random amplified polymorphic DNA (RAPD) method. Because 141 polymorphic bands were generated from 30 random primers selected through the primer screening, it was possible to analyze the genetic relationship among 6 Taraxacum species. In RAED with the primer OPC12, OPD16, OPK16, OPK17, OPK20, OPS1 or OPS8, many specific polymorphic bands have been appeared in each species. Especially RAPD with the primer OPS8, a specific polymorphic band at 564bp was appeared only in the naturalized Taraxacum officinale. Based on RAPD analysis, Korean native Taraxacum and naturalized Taraxacum species are divided into two groups. T. officinale and T. laevigatum are classified into group I which is a naturalized Taraxacum species group, and T. mongolicum, T. hallasanensis, T. ohwianum and T. coreanum are classified into group II which is a Korean native Taraxacum species group. The result from the RAPD method was very similar to the result from the Bootstrap method. From the examination of the physical characteristics of 6 Taraxacum species populated in Korea, flowering period of Taraxacum species in group I are longer than Taraxacum species in group ll, and the direction of involucral bract of Taruxacum species in the group I was also different comparing to the group ll. Because the flowering color, leaf direction, and the specificity of seed germination of T. coreanum were different compared to the other species in the group II, T. coreanum would be genetically divergent and showed the highest dissimilarity index score.

• Korean Journal of Environment and Ecology
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• 제25권6호
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• pp.819-827
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• 2011

Climate change is recognised as the best serious environmental problem in recent time, and high alpine or high latitudinal organisms especially endangered by its change. Leontice microrhyncha is recorded one of the endangered species by the Ministry of Environment Korea. We surveyed ten L. microrhyncha populations distributed at Taebaek Mountains, high mountain area in Kangwon province. L. microrhyncha is distributed 940m~1350m high altitude which equivalent of Warmth Index $53^{\circ}C{\cdot}month$ to $75^{\circ}C{\cdot}month$, the range of conspicuous cool temperate forest zone. The plant species distributed at slope of $5^{\circ}{\sim}23^{\circ}$ on northeast slopes. The vegetation structure at tree layer of L. microrhyncha distribution area is dominated by Quercus mongolica, Betula costata, Cornus controversa, Acer mono in tree layer, and by Staphylea bumalda, Deutzia glabrata, Stephanandra incisa in shrub layer. The species diversity of herb layer of each L. microrhyncha population showed from 0.21 to 0.98, and the importance value of L. microrhyncha in each population was the highest at blooming time of L. microrhyncha. These results will provide the basic information for the development of conservation strategies for this endangered species.

• The Korean Journal of Pesticide Science
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• 제17권4호
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• pp.440-447
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• 2013

F. occidentalis (WFT, western flower thrips) is a major pest in artificial chrysanthemum houses. Nnumber of WFT attracted to yellow sticky trap was highest at trap plant and lowest at 15 and 20m places away from trap plant. Number of WFT attracted to yellow stick trap when trap plant was placed in chrysanthemum house 30 days after planting (resident WFT) was 4.4~7.7 times more than at 5 and 10 m places away from trap plant and when trap plant was placed in chrysanthemum house immediately after planting (resident WFT) was 5.7~9.4 times more at 5 and 10 m places away from trap plant. Number of WFT between the place trap plant located and unlocated was undifferent when cultured chrysanthemum formed flower. In case of the plot that trap plant and natural enemy was used simultaneously, number of WFT was highter then chemicals plot. In case of the plot that trap plant and chamicals (chemicals was sprayed on trap plant only) WFT was controlled in trap plant place only but density of WFT on 5m and 10m places away from trap plant was increased. Therefore, WFT could be controlled effectively by use of trap plant (flowering yellow chrysanthemum) and natural enemy simultaneously.

• Korean journal of applied entomology
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• 제15권3호
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• pp.107-110
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• 1976

A Witches'-broom disease of jujube (Zizyphus jujuba) with which mycoplasma-like bodies are associated is wide spread in South Korea. Jujube trees with witches'-broom symptoms were selected from 15-20 year old planting and treated with solution of oxytetracycline hydrochloride (Terramycin). Treatments were 1) one injection on April; 2) one postharvest injection on October; 3) two injections (April and July); 4) three injections (April, June and August) and 5) an untreated control. Each injection consisted of 500ml of 1,000 p.p.m. solution of oxytetracycline HCl transfused into affected trees from plastic reservoir through plastic tubes connected to 3 small holes drilled in the basal part of the tree trunks. Complete remission of witches'-broom symptoms was accomplished within one growing season by one spring (April) injection. One postharvest (Oct.) injection also prevented the symptoms in the following growing season. Two and three injection treatments prevented the symptoms for at least two growing seasons and restored previously severely diseased trees to normal or near normal conditions. Remission of symptoms was found only above the injection site while current season witches'-brooms developed from areas below the injection site and from untreated main scaffolds. The results of this experiment demonstrates that transfusion treatment with oxytetracyclin HCl is feasible for the practical control of witches'-broom of jujube.

• Korean Journal of Agricultural Science
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• 제34권2호
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• pp.119-123
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• 2007

Germination ratio on the 300 collected genetic resources showed 80 to 100 percentage, but those of some accessions were very low as below 30 percentage. Early growth phase of most of these lines were very poor while some collected lines were very vigor. Range of stem height showed from 150 to 199cm, but that of some accessions showed below 100cm as five percentage and some of them was over 250cm as eight percentage. Number of tillers per plant appeared less one but some collected lines have two to three tillers per plant. In days to tasseling, some accessions showed more four per plant. Ear length of these accession showed above 60 percentage as 11 to 15cm, while that of some collected lines showed over 10 percentage as 16 to 20cm.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제38권4호
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• pp.336-342
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• 1993

To obtain the basic information necessary for the development of soybean varieties well adaptable to upland-paddy field rotational croppings, the difference of growth characteristics between upland and paddy-field including yield potentials of current recommending soybean varieties were evaluated. The growth characteristics, both above and under-ground, which were measured at flowering stage were generally greater in paddy-field but the number of root nodules was much greater in upland, thus the artificial inoculation was practically recommended for soybean growing in paddy-fields. Mean seed yield was generally higher in paddy-fields than in upland. All soybean varieties showed higher seed yield in the early planting date, April 20, were somewhat susceptible to soybean mosaic virus(SMV), thus they could be escaped from the disasterous endemic necrotic soybean mosaic virus(SMV-N). Soybean varieties showed over 4.0 tons/ha seed yield in the paddy-field were Williams 79, Union, SS77053, and Namhaekong. At the same time, Jangyeobkong and Danyeobkong were the most stable soybean varieties among the tested soybean varieties with less than 10% of coefficient variation values in all planting dates in paddy fields. Compared with Hwangkeumkong which is most widely being cultivated on farmer's fields, soybean varieties showed high yields in paddy-field were higher in plant height, less in the number of branches, and more in the number of nodes on main stem. At the same time, they had medium seed size which would bring the good germination and stands. Disease resistance especially for necrotic soybean mosaic virus was also one of the most decisive factors in seed yields for the early planted soybeans.

• Korean Journal of Medicinal Crop Science
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• 제14권3호
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• pp.158-162
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• 2006

Achyranthes bidentata was recorded to new medicinal crop in a revised 8th edition of the Korean pharmacopoeia. Therefore, A. bidentata began to use for same purpose with Achyranthes japonica which was cultivated since old times in Korea. This study was conducted to investigate the adaptability of A. bidentata in Korea. The germination rate and speed of A. bidentata seeds were higher than those of A. japonica in $15^{\circ}C\;and\;25^{\circ}C$. The growth of A. bidentata was greater than that of A. japonica until the 60 days after transplanting, but growth after that was the opposite. There were remarkable differences between two species in growth characteristics such as flowering date, leaf fall date, plant height, stem color and no. of branches. The flowering and leaf fall date of A. bidentata were earlier than A. japonica by July 7 and September 26. The plant height and number of branches of A.japonica were longer and more than A. bidentata, but the cluster length and no. of flowers per cluster of that were shorter and fewer than this. Number of supporting roots of A. bidentata and A. japonica was 10.7 and 14.6 per plant, respectively. The average yield was not different between two species. The yield of A. bidentata was 166 kg/l0 a in Suwon and 309 kg/10 a in Naju of Korea. The suitable cultivation region of A. bidentata was judged to southern area of Korea.

• Korean Journal of Medicinal Crop Science
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• 제12권6호
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• pp.437-441
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• 2004

These studies were conducted to investigate the proper method of nitrogen application for increasing the growth stability and quality in ballon flower (Platycodon grandiflorum A. DC.). In growth characteristics by split ratio of nitrogen application, stem diameter, number of branching roots and number of leaves were higher at the split ratio of 50:50 (nitrogen were splitted a half with basal application and the other half in autumn) than at 70:30. Root length, root diameter and number of branching root were higher at 50:50 than those of 70:30. The root yield was increased by 30% (230 kg/10a) at 50:50 compared with that of the 70:30. The crude saponin contents of root from 50:50 was 4.68%.