• Horticultural Science & Technology
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• v.18 no.4
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• pp.499-502
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• 2000

Five local cultivars of northern type garlics (Allium sativum L.) and one of southern type were collected, and their growth and developmental characteristics and productivity were investigated to select a well adaptable cultivar in Euiseong region. Local cultivars used in this experiment were 'Euiseong', 'Yeochun', 'Danyang', 'Jungsun', and 'Yongin' as northern type and 'Namdo' as southern one. The growth characteristic of local garlic cultivars were differed with their ecotypes and 'Namdo', a southern type cultivar, showed higher growth rate at the early growing stage than northern types. However, no clear differences were observed among northern types. Incidence of bolting was low in 'Jungsun' and 'Yongin', while high in 'Euiseong' and 'Yeochun'. In the case of incomplete bolting, however, an opposite trend was showed, thus, high in 'Jungsun' and low in 'Euiseong' and 'Yeochun'. Secondary growth was remarkably low in 'Euiseong'. Considering yield factors, 'Yeochun' seemed to be most promising northern type cultivar in Euiseong region, which showed highest bulb weight and largest cloves with high growth rate at the maximum growing stage. 'Danyang', 'Jungsun', and 'Yongin' seemed to have relatively low productivity in Euiseong region.

• Journal of Practical Agriculture & Fisheries Research
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• v.19 no.1
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• pp.25-38
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• 2017

More than 90 percent of domestic consumption of the lettuce occupied leaf lettuce, and the farmer preferred high yield, late bolting and stable expression of anthocyanins. So, this research focused on making resistant to disease, late bolting, and good expression of anthocyanin for lettuce. Based on these characteristic's parents, 11 crosses were created. So we advanced the generation and investigated each generation from F₁ to F₇. In this year, we selected 90 combination 221 lines which was F₂ 42 combination 137 lines, F₃ 4 combination 17 lines, F4 11 combination 27 lines, F₅ 7 combination 30 lines, F₆ 1 combination 2 lines, F₇ 3 combination 8 lines. Among the selected 17 lines, 5007, 5014, 6004, 6005, 6021, 6023, 7001, 7002, 7006, 7007, 7010, 7011, 7015, 7018, 7019, and 7021 which were late bolting and good expression of anthocyanins were investigated their yield. Finally, we selected 5 lines 7001, 7002, 7011, 7018 and 7022 in this year.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.18-18
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• 2021

Gomchwi using stuffed leaves is many cultivated for 'Gondalbi(Ligularia stenocephala)' among Gomchwi species. 'Gondalbi' species like to be cultivation on farm because of low the incense and the bitter taste, and high yield. But 'Gondalbi' caused to curtail yield that susceptibility of powdery mildew disease and shriveling and death of plant on summer season. To solve this problems, we crossed a Gomchwi and 'Handeari-gomchwi' to have resistance of powdery mildew disease and high yield. A new Gomchwi cultivar 'Jinmani' was bred by crossing between Gomchwi (Ligularia fischeri (Ledeb.) Turcz.) and Handaeri-gomchwi (Ligularia fischeri var. spiciformis Nakai). The selection and investigation of growth and yield characteristics were conducted from 2007 to 2020 in field and greenhouse of Highland Agriculture Research Institute, NICS, Rural Development Administration. The color of petiole ear was purple. trichome of petiole and leaf back non-existed, and luster of leaf back existed. Density of leaf vein was 4 degree among 1-5 degree in a newly developed cultivar 'Jinmani'. Plant height, leaf length, leaf width and petiole length were 55.7, 21.8, 22.2, and 33.9 cm, respectively in the 2nd year of growth characteristics. Plant size was similar with that of 'Gommany'. Bolting and flowering time were Aug. 5 and Sept. 5, respectively, and Bolting and flowering time of 'Gommany' showed similar to Aug. 8 and Sept. 1, respectively. 'Jinmani' showed higher number of leaves (202 ea.) per plant compared to 'Gommany' (159 ea.). Furthermore, yield was 67.9% higher in 'Jinmani' (2,569 g/plant) than in 'Gommany' (1,530 g/plant). 'Jinmani' showed lower leaf thickness (0.66mm) than 'Gommany' (0.69 mm), and consequently showed more hardness in leaf characteristics (25.1 kg/²) compared to 'Gommany' (24.3kg/cm²). 'Jinmani' showed similar strong resistance compared to 'Gommany' in the susceptibility of powdery mildew disease.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.7
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• pp.875-881
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• 2013

The failure of a bolted joint owing to stress corrosion cracking (SCC) has been considered one of the most important structural integrity issues in a nuclear power plant. In this study, the failure possibility of bolting, which is used to support the steam generator of a pressurized water reactor, owing to SCC and brittle fracture was evaluated in accordance with guidelines proposed by the Electric Power Research Institute, which are called the Reference Flaw Factor method. For this evaluation, first, detailed finite element stress analyses were conducted to obtain the actual nominal stresses of bolting in which either service loads or bolt preloads were considered. Based on these nominal stresses, the structural integrity of bolting was addressed from the viewpoints of SCC and toughness. In addition, the accuracy of the EPRI Reference Flaw Factor for assessing bolting failure was investigated using finite element fracture mechanics analyses.

• Korean Journal of Medicinal Crop Science
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• v.10 no.5
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• pp.419-422
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• 2002

Korean angelica(Angelica gigas Nakai), a oriental medicinal plants is important and in great demand in Korea. This crop is a biennial which is to die after flower, so as could not harvest the root. A new variety 'Anpung' was developed from the selection of the local collecting population by medicinal crop team at NCES in 2001. This showed stable bolting during its cropping year and have high quality and yield potential. The color is greenish purple in stem and red purple in flower. It was longer in plant height and root length, thicker in root diameter, more leave and latheral roots comparing with the check variety 'Manchu'. The dry root was 72 g/plant showing heavier than check variety of 65 g/plant. It showed such low bolting rate as 0.5%, on the other hand 49.3% in landrace when it cultured by transplanting with heating nursery seedlings, and $0{\sim}15%$ with field nursery seedlings. The dry root yield of the variety was averaged 3,630 kg/ha out yielding the check variety by 11% at the three regional yield test from 1999 to 2001. Finally, 'Anpung' showed higher content of extracts up to 46.3% in 'Anpung' and 45% in check variety, decursin and decursinol contents was 3.48% and 2.79%, showing slightly higher than check variety.

• Korean Journal of Medicinal Crop Science
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• v.6 no.2
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• pp.160-164
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• 1998

Angelica gigas has been a major medicinal crop in Korea for a long time. This study was to determine optimum seeding time and bolting response by shifting seeding time between November 10, 1993, and August 10, 1994 using promising line, Suwon 2. Days to emergence were similar among seeding times from April 10 to August 10 in Suwon. Seedling duration was shortened 92 days when seeded on July 10 compared with the conventional seeding time of April 10. Productivity of seedling ranging from 0.31 to 0.70cm in diameter was highest of 730 plants per $m^2$ in July 10 seeding. When seeded in July 10, bolting rate was 2.4 percent as compared with 2.6 percent in conventional seeding (April 10). The optimum seeding time was July 10. Seedling quality, survival rate after planting in field, and root yield were greatly influenced by seeding time.

• Korean Journal of Medicinal Crop Science
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• v.8 no.3
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• pp.283-289
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• 2000

This study was to determine optimal sizeof root top using Suwon 2 selected from the Jinbu local population though pure line selection and five root head diameters of $0.11{\sim}0.30,\;0.31{\sim}0.50,\;0.51{\sim}0.70,\;0.71{\sim}0.90\;and\;0.91{\sim}1.10cm$. Emergence rate, characteristics of top, and root were increased with increasing diameterof seedling root. In the group of root head diameter from 0.51cm to 0.70cm, bolting rate was the lowest being less than 3.3% and root yield was the highest being more than 300kg/l0a. Bolting rate was positively correlated with plant height while showed negatively correlated with root yield. The study showed that the optimum of root head diameter raised seedlings in the open field appeared to be from 0.31 to 0.70cm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1529-1539
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• 2013

Recent case studies in Japan have shown that rockbolts are commonly installed at an oblique angle to the excavation direction of the tunnel, instead of at a right angle, due to restriction of the working space. In particular, in the case of expansion in an existing tunnel, the working space can be very small, due to the large protective structures necessary to operate within an existing tunnel. In this case, where both the current use of the existing tunnel, and the reinforcement of the ground around the tunnel are required, the effects of installation angles and patterns of rockbolts are important factors in the design process. Therefore, in this study, a total number of 24 model tests are performed, to investigate the reinforcing effects of system bolting installed obliquely from the excavation direction of the tunnel, by changing the installation angle of bolts, longitudinal distance, and bonded length of bolts. The model test results indicate that the relaxed load ratio decreases, with the increase of both the bonded lengths and the number of the installed bolts, resulting in the decrease of the supported area by one bolt. Two-dimensional numerical analysis, which considered the reinforcement effect of inclined system bolting as the change of engineering properties near the tunnel, demonstrated that the deflection patterns at the tunnel crown in the numerical simulations, show a similar tendency to those measured in the model tests.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.2
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• pp.151-158
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• 1993

Since the inhibition of floral induction was considered to be an important subject to get high yield of Angelica gigas, the effects of low temperature, daylengh and shading were investigated in this study. The yield of A. gigas root grown by inhibition of floral induction was compared with the yield obtained by traditional cultivation method. When the seedings were exposed to the natural low air temperature condition until late of November, the plants which had 6 to 8 leaves showed vernalizing effect, and when the low temperature treatment was prolonged until mid of January, 4 to 5 leaf plants showed vernalizing effect. But 2 to 3 leaf plants did not show vernalizing effect regardless of the length of chilling treatment. The effectiveness of exposure to low temperature was markedly dependent upon the age of plants. In the artificial low temperature treatment the range of temperature varied with plant age. Vernalizing effect at 1,5 and 9$^{\circ}C$ of temperature did not show 3,5,6 leaf plants, respectively. The bolting percent in 8 leaf plant at 1,5 and 9$^{\circ}C$ for 8 weeks decreased by 80,45 and 5%, respectively. As daylength became longer, the bolting percent of A. gigas was increased. plants which were grown in the full sunlight showed the highest value in bolting percent, and the bolting percent was not decreased significantly with changing from full sunlight to 50% shading. When A. gigas were grown by the inhibition of floral induction, dry root weight per l0a showed the greatest value in 3 year old plant which 3.6 and 2.4 times higher than that of 1 and 2 year old plant, respectively. The yield of root was increased by 73.7% in 2 year old plant and 159.6% in 3 year old plant compared with the yield obtained by traditional cultivation method.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.579-582
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• 2009

A new red leaf lettuce (Lactuca sativa L.) cultivar, "Mihong" which has late bolting and deep red leaf color was developed from a cross of "Danhongongchukmyeon" (deep red but early bolting and low yield) and "Hajicheongchukmyeon" (late bolting and high yield). The selection and breeding of advanced lines were done by pedigree method during 2000-2006. The advanced lines were evaluated for yield and adaptability in Korea (Gangwon, Kyunggi, Chungbuk, Kyungnam, Jeonnam, Jeonbuk, and Jeju) from 2007 to 2008. The "Mihong" has gray seed color, traverse elliptic leaves and deep red color. Compared to "Dukseomjeokchukmyeon", marketable yield of "Mihong" was higher by 2% (at 291 g per plant) as a 17.3 ton/ha, but with particularly improved good expression of deep red leaf color in high temperature cultivation in the field. The shelf-life of "Mihong" was three weeks longer than "Dukseomjeokchukmyeon" at $4^{\circ}C$. The amount of anthocyanin content of "Mihong" were higher than with "Dukseomjeokchukmyeon" at 28.9 mg/100 g. Especially the degree of leaf hardness in "Mihong" showed $26.9kg/cm^2$ compared to "Dukseomjeokchukmyeon". therefore, its taste is better, more crispy, and sweeter than "Dukseomjeokchukmyeon" This new cultivar "Mihong" can be cultivated in all year around even if summer time cultivation.