• Korean journal of applied entomology
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• v.24 no.1 s.62
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• pp.7-10
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• 1985

Transplanting date, planting space and nitrogen level were evaluated for disease development of rice sheath blight using two rice cultivars, Jinheung and Yushin. Sheath blight disease was more severe in early transplanting plot (May 16), narrow planting space($27{\times}12cm$) and high nitrogen level (220kg/ha for Jinheung and 300kg/ha for Yushin) conditions than in May 26 transplanting plot, wide planting space ($27{\times}15cm$) and standard nitrogen level (110kg/ha and l50kg/ha). At the same time, cultural conditions favorable for disease development during growth stage resulted in greater damage at maturing stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.132-135
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• 2005

The water absorption ratio was not affected by the planting dates. Hannamkong showed higher water absorption ratio than any sprout -soybean varieties. Soybean seeds produced from later planting showed higher germination percentage than those planted May 25. Pungsannamulkong, Eunhakong, Doremikong, and Someongkong showed over $90\%$ germination after two days, while Tawonkong and Hannamkong were lower, The germination ratio test of the soybean seeds at $25^{\circ}C$ is usually for 7 days. But, germination ratio test of seeds used for sprout-soybean is suitable for 3 days at $25^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.558-562
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• 1996

The growth and yield of Job's tears (Coix lacryma-jobi L.) under the flooded paddy and upland (dry paddy) field conditions were compared at three sowing dates and two planting densities. Job's tears grown under flooded paddy field was much shorter in plant height, but greater in number of tillers than those grown under upland. Photosynthesis rate of Job's tears grown under flooded paddy field was higher and the weight of dry roots heavier but the damages of pest and leaf blight disease smaller than those grown under upland. For the above mentioned reasons, the grain yield of Job's tears grown under flooded paddy field was higher by up to 85% than that grown under upland. There was no significant difference in grain yield between the planting densities. The earlier sowing brought about the less grain yield in upland field condition, while sowing plot on the 15th of May showed the highest grain yield in the flooded paddy field condition.

• Korean Journal of Medicinal Crop Science
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• v.1 no.2
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• pp.158-161
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• 1993

This experiments were carried out determine planting date for highest Yields and select an covering material for enhancement of environments in Cassia tora L.The highest Yields by regressions estimate produced 352 kg/10a at May 18. of coure, it is possible to plant at June and early-July in spite of slight decreas of Yields, therefore Cassia tora L. is benefit to establish cropping system with barley, wheat or other crops. The covering materials for highest yielding was Black-white nonporous PE(low density) and it out yielded about 53% than conventional cultivations. Cassia tora L. is possible to produce Without agricultural medicines because of little occurence of decrease except occuring of Damping off(Rhizoctonia solanikuhn) at early planting.

• Journal of People, Plants, and Environment
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• v.23 no.3
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• pp.347-362
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• 2020

Background and objective: It is difficult to conclusively determine the exact cause of tree defects since multiple causes are involved such as climate change, plantation, tree quality and planting time, construction, planting base, drainage, sunshine conditions, maintenance, and microclimate. The data related to landscaping construction defects are scattered or fragmented by companies and years, but not managed systematically by the defect information management system. Most of the earlier studies associated with tree defects in apartment complexes suggested defect rates after examining tree defects in the completed construction site and proposed fragmentary and subjective conclusions about the causes of defects observed in trees with high defect rates. It is proposed to continue to conduct studies on the establishment and analysis of systematic databases to identify the exact causes of tree defects and measures to improve, and the need to accumulate systematic data in the construction process where many defects arises. This study was conducted to reduce the defects of trees planted in apartment complexes. Methods: Main factors related to tree defects were subdivided based on the results of literature review and a defect investigation at the completion site, and tree history management items were selected and subdivided during the construction stage. Results: The criteria for the preparation of subdivided items were obtained, and the tree history management checklist was written for the site under actual construction and a systematic database was established. Items that are categorized based to the causes of defects include the location of nurseries, date, tree quality, site conditions, planting techniques, microclimates, and maintenance. Conclusion: This study suggested tree history management items based on the tree defects that can be identified at the construction stage and applied them to the selected study site, which differentiates this study from earlier studies. It will be necessary to conduct a comprehensive and objective time series analysis on tree defects that occur over time by continuously monitoring and collecting data after construction.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.1
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• pp.30-39
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• 1989

Forage productivity of cropping systems of rye - silage corn, silage corn - oats, silage corn - rape was studied in the south-eastern part of Korea where rice black-streaked dwarf virus(RBSDV) infection of corn are severe. Rye(cv. Paldanghomil) was planted on Oct. 20 of 1986 and harvested 10 times from April 5 to May 5 at the 5-day intervals in 1987, corn (cv. Suweon 19 and Jinjuok) was planted 5 times from April 5 to May 15 at the 10-day intervals in 1987, and oats(cv. Megwiri) and rape (cv. Velox) were planted 4 times from Sept: 4 to 25 at the 7-day intervals and harvested 4 times from Nov. 10 to Dec. 10 at the 10-day intervals in 1987. Considering yield, nutrition value, and in vitro dry matter digestibility (IVDMD), forage productivity of the cropping systems was compared. As harvesting time of rye delayed, plant height, dry matter(DM) yield, percent DM, crude fiber, and digestible DM yield increased, but crude protein, crude fat, and IVDMD decreased. However, nitrogen free extract was not different among the harvesting dates. As planting date of corn delayed, RBSDV infection rate increased. but DM yield of silage decreased. However, silage yield of Jinjuok was higher, but RBSDV infection rate was lower compared with Suweon 19 at all planting dates. DM yield of oats and rape decreased as planting date delayed. However, at Sept. 4 and 11 plantings yield of oats on Nov. 10 was much lower than that of rape, but the differences in yield between two crops decreased with delayed harvesting, and yield was similar on Dec. 10. A cropping system harvesting rye around April 20 and followed by planting corn in late April was best among the rye-corn systems considering yield and nutrition value of both crops. However, among the corn-oats or corn-rape cropping systems early April planting of corn and followed by early Sept. planting of oats or rape showed best results with similar yield potential of the best rye-corn cropping system.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.2
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• pp.177-186
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• 1997

A field experiment was conducted to evaluate growth characteristics, dry matter yield and crude protein yield according to different planting dates at sorghum $\times$ sudangrass hybrid(SSH) and soybean intercropping. Planting dates were five treatment of may 6(Tl), may 13(T2), may 20(T3), may 27(T4) and june 3(T5), and cutting frequency was two times a year. 1. Plant length of SSH was the highest at T2 as 253cm, but T5 was the shortest as 203cm. In the soybean, T3 and T4 were the highest as 113cm, respectively. Leaf length of SSH was high at T5. In the soybean, T2 was the highest as 17cm. Average leaf width of T2, T3 and T4 was higher than TI and T5. 2. Leaf number of T3(SSH and soybean) was higher than other treatments, Stem diameter of SSH and soybean showed the highest as 12.3mm and 8.6mrn at T5 and T3, respectively. In the SSY mean stem hardness of TI was the highest as 2.5kg/$cm^2$, but soybean was the highest at T1(8.0kg/$cm^2$) 3. Deed stubble according to move seeding date of SSH were 11.4 percentage at TI, and 3.9 percentage at T5 treatment. 4. Total dry matter yield according to move seeding date was the highest at T3 as 20,937kghq but T5 of late seeding was the lowest as 16,04Okgha(P < 0.05). 5. In the first cutting time, protein content of SSH was the highest at T3 as 9.9 percentage, but T1 was the lowest as 8.4 percentage. In the 2nd cutting, T5 was the highest as 8.7% but T1 was the lowest as 6.2%. In the soybean, T5 was the highest as 19.4% but TI of early seeding was the lowest as 16.2 percentage. Crude protein yield was the highest at T3 as 2,233.5kghq but TI of early seeding was the lowest as 1,579.7kgha (P < 0.05). As mentioned above the results, T2(may 13), T3(may 20) and T4(may 27) treatment could be recommended as the best suitable seeding date when drymatter and protein yield were considered.

• Korean Journal of Plant Resources
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• v.8 no.2
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• pp.209-215
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• 1995

This experiment was carried out to elucidate the effect of row width and hill space on growth and yield in cynanchum wilfordii on experimental fields of chungbuk Provincial Rural Development Administration. Emergence date was May 25 and had no differences between planting density. Vine length was 219cm with row 40cm, 220cm, with 50cm and 225cm with 60cm, and in hill spaces, it was 225cm with hill space 10cm, 219cm with 15cm, and 218cm with 20cm. No. of leaves was same tendencies to vine length and was more increased as the hill space was narrower. Root length was longer about 0.9cm to 1.4cm as the hill space was wider, and no. of root had no difference between planting tensity. Yield was more increased row width was wider and was decreased hill space was wider. And the profitalble planting density was row width 50cm and hill space 10cm in the cultivation cynanchum wilfordii.

• Korean Journal of Medicinal Crop Science
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• v.2 no.2
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• pp.114-120
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• 1994

Experiment was conducted to investigate the effects of planting date and planting methods with seedling size on bolting and yield of Ostericum koreanum (MAX.) KITAGAWA Seeding methods were also reviewed to imvestigate their effects on seedling characteristics. This experiment was carried out in Chuncheon during 1988 growing season. The small seeding rate and broadcasting had higher rates of emergence than the others. There was no big difference in seedling size by seedling rate, and more seedling growth was in drilling methods among seed planting methods. The quantity of seedling were produced with the order of medium, small and lastly large seedling. Dense planting $(8l\;/33m^2)$ was advantageous in producing small seedling. Large seedling had earlier flowering than the others and growth was good in planting small seedling with drilling method. The rates of bolting by seedling sizes were 89.6% in large, 64.6% in medium and 36.9% in small seedling. Bolting was influenced the root Quality by producing lignified root which had a least commercial value. More root growth was shown in unbolting plant compared to bolting plant seedling and broadcasting had much more root growth than seedling from drilling. Fresh root yield of unbolting plant was higher than that of bolting plant and highest yield was obtained in the broadcasting plot with small seedling.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.13-13
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• 2017

By the progress of genome sequencing, infrastructures for marker-assisted breeding (MAB) of rice came to be established. Fine mapping and gene isolation have been conducted using the breeding materials derived from natural variations and artificial mutants. Such genetic analysis by the genome-wide dense markers provided us the knowledge about the many genes controlling important traits. We identified several genes or quantitative trait loci (QTL) for heading date, blast resistance, eating quality, high-temperature stress tolerance, and so on. NILs of each gene controlling heading date contribute to elongate the rice harvest period. Determination of precise gene location of blast resistance gene pi21, allowed us to overcome linkage drag, co-introduction of undesirable eating quality. We could also breed the first practical rice cultivar in Japan with a brown planthopper resistance gene bph11 in the genetic back-ground of an elite cultivar. Discovery of major and minor QTLs for good eating quality allowed us to fine-tune of eating quality according to the rice planting area or usage of rice grain. Many rice cultivars have bred efficiently by MAB for several traits, or by marker-assisted backcross breeding through chromosome segment substitution lines (CSSLs) using genetically diverse accessions. We are also systematically supporting the crop breeding of other sectors by MAB or by providing resources such as CSSLs. It is possible to pyramid many genes for important traits by using MAB, but is still difficult to improve the yielding ability. We are performing a Genomic Selection (GS) for improvement of rice biomass and grain yield. We are also trying to apply the genome editing technology for high yield rice breeding.