• Journal of Environmental Science International
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• v.25 no.6
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• pp.889-895
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• 2016

In Danseong-myeon (myeon is a subdivision of), Sancheong-gun, and Sugok-myeon, Jinju City, pot seedling culture was used at the rates of 100% and 62%, respectively. Root restriction seedling culture was used relatively more frequently than pot seedling culture in Yangchon-myeon, Nonsan City, Guryong-myeon, Buyeo-gun, and Wolsan-myeon, Damyang-gun. Open-field seedling culture was used at the rates of 80% and 54% in Samnangjin-eup (eup is a subdivision of a gun), Miryang City and Ssangnim-myeon, Goryeong-gun, respectively. In Danseong, Sancheong, and Sugok, Jinju, granite soil was used as the medium for pot seedling culture at the rates of 90% and 80%, respectively. In Yangchon, Nonsan, Wolsan, Damyang, and Ssangnim, Goryeong, commercial bed soil and coir dust were used for seedling culture at the rates of 73%, 64%, and 60%, respectively. At the main production sites, the use of granite soil for seedling culture, highest rate in 2000-2005, continued to decrease; in 2011-2013, granite soil was used at the rate of 37%, while commercial bed soil and coir dust were used at the rates of 32% and 14%, respectively. The bulk density of commercial bed soil, expanded rice hulls, and coir dust was $0.11-0.16g/cm^{-3}$. Coir dust was the lightest material but had the highest and, 36.7% and 21.8%, respectively. In sandy loam soil and granite soil was low. The pH of all growth media was between 5.4 and 7.0, and the values were in the range of $0.15-0.66dS{\cdot}m^{-1}$. However it was necessary, to adjust the pH levels and enhance the of expanded rice hulls, sandy loam soil, and granite soil. Similarly, the fertilizer concentration and air permeability of coir dust need to be adjusted.

• Journal of Biosystems Engineering
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• v.21 no.2
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• pp.123-133
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• 1996

An automatic drum seeder was developed to improve the seeding operation. It consisted of a conveyor to transfer seedling trays, a seed-hopper to supply seeds, a drum to drop seeds on the tray, and an air blower to remove extra seeds. A photo sensor was used to detect the transfer of seedling trays, and its signal was fed into microcomputer which operated a stepping motor driving the drum. The seeds were adhered to the surface of drum by vacuum pressure, and were dropped into tray cells by compressed air. An air connection unit was devised to alternate between vacuum pressure and compressed air. A control program for the system, written in C language, could operate the drum at the given number of revolutions and revolutions per minute. The results showed that the air connection unit could operate well and the seeds were dropped satisfactorily into tray cells. In case of cabbage and perilla seeds, which are regular and spherical shape, the missing rate was low and the single seeding rate was more than 97%. Low missing rate and high multiple seeding rate were observed in lettuce seeds which have narrow ends with tight weight. The missing rate of pepper seed was very high because of heavy weight and irregular shape. To improve the performance of the seeder, adjustment of vacuum pressure based upon shape and weight of the seeds, careful selection of the material of drum, maintenance of consistent air blower pressure, and replacement of stepping motor to DC motor are recommended.

• Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.11.1-11.11
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• 2020

We tried to find the optimal growth conditions of sea cucumber and to analyze the economic effectiveness of the sea cucumber seedling release project in Korea. We first examined the optimal growth conditions of sea cucumber in the relating literatures. Then, we analyzed the economic effectiveness of the sea cucumber seedling release project of the Woncheon fishing village union of Gyeongnam Province in 2016-2018 by using the cost benefit analysis method. The net income of the release project of the Woncheon fishing village union was 69,850 Korean won. The benefit to cost ratio of the sea cucumber seedling release project of the Woncheon fishing village union was estimated to be 1.7, indicating that the project was economically feasible. In order to improve the economic feasibility of the sea cucumber release project, as we see in the case of the Woncheon fishing village union, it is necessary to manage the purchase of the sea cucumber seedling, to improve the recapture rate of sea cucumber, and to manage marketing of sea cucumber.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.190-191
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• 2000

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.360-365
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• 1993

The infant seedling of rice(8-to 10-day-old) has often suffered from submergence just after transplanting due to the too short seedling height, 5 to 8cm, This experiment was conducted to elucidate the effect of gibberellic acid($GA_3 : 25% soluble liquid) with the application methods of foliar spray and seed-soaking on the elongation of seedling height of infant rice seedling in machine transplanting, We used a japonica rice variety, Hwaseongbyeo, and the seeding rate was 200g per seed tray(30$\times60$\times3cm). Generally,$GA_3 and Metalaxyl increased the elongation of seedling height of infant seedling while Tetracycle decreased the seedling height, To increase the seedling height of infant seedling, the foliar spary application of $GA_3 was better than seed-soaking treatment. The optimum concentration of $GA_3 for the foliar spray was about l0ppm and the optimum application time of $GA_3 was 3 to 4 days after sowing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.1
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• pp.28-31
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• 2005

To identify salt-tolerance characteristics of corn seedling was treated in solution of 0, 50 and 100 mM NaCl of hydroponic cultivation. In photosynthesis of corn seedling, there was no large difference between 50mM and 0 mM NaCl solution, however, in 100 mM NaCl solution, the tolerance gradually decreased to $76\%,\;49\%,\;and\;31\%$ after one day, four days, and seven days, respectively, in comparison to 0 mM NaCl solution. Osmotic potential of corn in seedling period was significantly decreased with increasing saline level, however, free proline content in the plant on the ground was significantly increased with increasing saline level and with the lapse of time. In terms of correlation among major characteristics, there was a highly significant positive difference between osmotic pressure potential and photosynthesis, However, highly negative correlation was found between osmotic pressure potential and free proline content. In addition, it was expected that young seedling of corn with saline tolerance may be utilized in the transplantation in salt-accumulated land. Based on above-shown result, in terms of saline tolerance of Chalok-2 variety, growth suppression was serious with 100mM NaCl solution. However, growth was expected that seedling growth would be favorable under 50 mM NaCl solution.

• Korean Journal of Medicinal Crop Science
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• v.21 no.1
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• pp.20-26
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• 2013

This study was conducted to improve the managing and storing methods of the seeds of Aralia cordata var. continentalis (Kitagawa) Y.C.Chu, to examine the viability and the germination ability of seeds with different storing conditions and methods, and to develop new ways to propagate and have better healthy seedling. Therefore, the germination rate, days required for germinating seeds, and early growth responses of Aralia cordata var. continentalis (Kitagawa) Y.C.Chu were investigated with different storing temperatures, durations and methods. The germination rate was higher in stratified storage than that in dry storage condition. The highest germination rate was with outdoor temperature at 30 days after stratified storage. The days required for germinating seeds were less than 10 days with the treatment of $25^{\circ}C$ and outdoor temperature in stratified storage. In dry condition, they were shorter with $4^{\circ}C$ and $25^{\circ}C$ than those with $-20^{\circ}C$ and outdoor temperature. Leaf number of seedling was higher in stratified storage compared to that in dry condition, while it was not clearly different according to storage temperatures and durations. Leaf length and leaf width of seedling was not difference among the treatment of storage methods, temperatures, and durations. Stem length of seedling was higher in stratified storage than those in dry condition, while root length was not clearly different among the treatments. It would be assumed that temperatures, methods and durations of storage could affect much to the germination rate and the early seedling growth response.

• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.29-35
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• 2022

Elsholtzia byeonsanensis is a Korean native plant of the Lamiaceae family, and was first introduced in the Korean Journal of Plant Taxonomy. This plant has a short plant length of 20-35 cm, with leathery and glossy leaves. The purple flowers bloom in November, so they are highly useful as potted or ground cover ornamental plants. In this study, tray cell size (128, 162, and 200-cell trays), soil composition [horticultural soil (HS): decomposed granite (DG) 1:1, 1:2, and 1:4 (v:v)], seeding rate (1, 2, and 3 seeds per cell) and additional fertilizer concentrations (0, 250, 500, and 1000 mg/L Hyponex) were tested to find out the optimum seedling growth conditions. As a result of the study, E. byeonsanensis growth increased proportionally as the cell size of the tray increased. The growth was inhibited as the percentage of DG increased. As for the growth according to the seeding rate, plant height, plant width, leaf length, and leaf width decreased as the seeding rate increased, but there was no difference in the number of leaves, stem diameter, and root length. There was an increasing trend in seedling growth as the additional fertilizer concentration increased. Therefore, for producing E. byeonsanensis seedling, it is most effective to fill HS or HS:DG 1:1 in 128-cell trays, sow one seed per cell, and spray the seedling at 1000 mg/L for additional fertilizer.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.4
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• pp.288-294
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• 1994

Seedling vigor of introgressive hybrids between birdsfoot refoil 'MO-20"(Lotus corniculatus) used as the maternal parent and tetraploid(2n=4x=24)accession PI302921 narrowleaf trefoil(Lotus corniculatus L.), and parents were compared in terms of dry matter accumulation , net photosynthetic rate, dark respiration rate, and growth analysis. The hybrids showed better seedling vigor than PI302921 as they had lower dark respiration rate and higher relative growth rate (RGR) than PI302921. Hybrids grew faster than MO-20, but there was not significant difference between them. Net photosynthesis per unit area increased during three weeks after emergence without difference among the entries, then decreased sharply with leaf age and shading marking much differences among entries Dark respiration rate was very high just after emergence, after which it decreased rapidly until it reached a stable level at 1 week through 3 weeks of age, and then dropped again. In general, dark respiration, photosynthesis, and seedling growth of the hybrid was similar to those if MO-20. Although there are some reports about interspecific hybrids of Lotus species, it still remains as a new area for genetic improvement of seedling vigor of L. corniculatus.atus.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.112-119
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• 1986

The variations of antibiosis to whitebacked planthopper (Sogatella furcifera Horvath) in resistant varieties, N 22 (Wbph 1) and ARC 10239 (Wbph 2) was investigated at different seedling ages and different tillers within a plant. The antibiosis of the rice plants to the insect was measured as the nymphal survival rate on the rice plants. The survival rate of the WBPH on N 22 was greater than on ARC 10239. It was also different at different seedling ages and the tillers within a plant with different tendency of two resistant rice genotypes, N 22 and ARC 10239. NO significant differences of nymphal survival rate was found between 7 and 30 days old seedlings on N 22, and greatly reduced on the 60 days old seedling. On the other hand it was increased up to on 30 days old seedlings and gradually decreased from on 40 days old seedlings of ARC 10239. The nymphal survival rate was greater in tillers than in the main culm of the rice plants.