• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.328-333
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• 1983

Due to fast industrialization and reduced agricultural population, there has been increased farm mechanization to reduce the labor requirement. In rice production, mechanical transplanting has been increasingly popular due to the heavy labor requirement in hand transplanting and development of convenient transplanters. For mechanical transplanting, rice seedlings is grown in boxes with limited soils under super dense population, thus short period of exposure to unfavorable temperature and poor water management would cause severe damage to rice seedlings such as seedling damping off and the similar physiological disorders. Several chemicals were evaluated for their effectiveness to control the disease and disorders, and other effects as plant growth stimulants. 3-hydroxy-5-methylisoxazole-a soil fungicide, Metalozyl-a fungicide which controls mildew, SF 8002-the composite of above two chemicals, and Isoprothiolane-a fungicide which controls rice blast were found to be effective controling seedling damping off and similar physiological disorders, and improvement of physiological characteristics of the seedlings such as the amount of bleeding sap, rooting ability, negative geotrophism, and regrowth after cutting. The results indicated that the chemicals will be very effective raising healthy seedlings even under unfavorable environments by the improvement of physiological activities of seedlings and preventing seedling damping off and the similar physiological disorders.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.277-282
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• 2006

For searching the natural herbicide-components, the seed germination and seedling growth of receptor plant species (Brassica campestris, Sesamum indicum, Perilla frutescens and Echinochloa crus-galli) were investigated in four solvent-extracts extracted from Coptis chinensis Franch. The seed germination of receptor plant species was largely inhibited in 2,000 ppm of ethyl acetate compared to the control, and it was inhibited in order of P. frutescens, B. campestris, E. crux-galli, and S. indicum. In seedling growth, the shoot and root elongations of receptor plant species were inhibited in order of S. indicum, P. frutescens, B. campostris, and E. crus-galli. Root elongation was remarkably reduced in order of $H_2O$, butyl alcohol, and hexane, ethyl acetate extracts. Of four receptor plant species, seed germination and seedling growth of B. campestris and S. indicum showed the species-specific reaction to the solvent-extracts extracted from C. chinemis. $H_2O$ extract had a natural herbicide potential to the seed germination or root elongation in B. campestris and S. indicum. The result can be provided a basic data f3r the development of natural herbicide.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.2
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• pp.71-81
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• 2002

The study was carried out to develop nursery soil for rice seedling of phyllite. First of all, physico-chemical properties of used phyllite in the study through the analysis for agricultural utilization evaluation are as following. Bulk density(BD) of phyllite was $1.31g/cm^3$ each other and porosity had 65% of entire pore size. Also, the water holding capacity(WHC) was 43% at 1/3bar pressure, which phyllite has high WHC. According to, the results the experiments for nursery soil were conducted by mixing the materials such as phyllite, zeolite and hill soil. The mixing ratios were 30, 50, and 70% for zeolite and hill soil into phyllite. These mixed materials were packed in a box by adding 0, 1 and 2g of N-fertilizer. At seedling test, there were increases in the growth of shoot and root of rice for phyllite to zeolite and phyllite to hill soil, respectively. On the other hand, the length of leaf increased with increasing application rate of phyllite, while length and a number of root increased with increasing application rate of hill soil. The growth in the plots of phyllite to zeolite and phyllite to hill soil was better than in control plot. Finally, phyllite plot had efficient results when it compared with others and the study used with phyllite will have to more research and effort for agricultural useful material.

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.25-31
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• 2009

This study was conducted in order to breed Japonica salt tolerant rice and select salinity tolerant lines by establishing reliable and practical method of screening voluminous materials. Salinized nutrient solution by adding NaCl was effective compared with the salinized nutrient solution by adding 0.3%, 0.6% and 0.7% of diluted sea water. There was no different visual score of salinity injury between salinization using tap water and distilled water. Seedling salinity tolerant lines between region and order by year were showed very stable and reproducible results, 3~4.2 of visual score at Gyehwado-substation and International Rice Research Institute (IRRI, Philippines) in 2002, 2003 and 2004. Heading date of 6 selected seedling salt tolerant lines showed a range of 16. Aug.~21. Aug. and delayed 2~6 days than that of Donjinbyeo. Percentage of ripened grain and yield of milled rice in 6 lines was lower, 52.2~14.7% and 50~5%, respectively than those of Donjinbyeo.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.135-138
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• 2003

Appropriate allocation of personal and financial resources of a research organization is important for the successful accomplishment of its goals. Direct-seeding of rice is a technology compatible with sustainable agriculturer and much research on the technology has been carried out in the research institutes of Rural Development Adminstration (RDA). We analyzed, with a special interest in research on rice direct-seeding technology, patterns of resource allocation in RDA by technology to evaluate congruency levels in research resource allocation. Research on direct-seeding technology had been focused on its fundamental field in the past. However, research to solve the practical difficulties encountered by farmers such as those in seedling establishment weed control, and water management practices, has been increased in recent years. Research resource allocation had largely been made to the projects for variety and seeding-technology development in the early years, however, allocation to the projects for the fertilization, weed control, and water management fields has been increased in recent years. Allocation of resources to the projects in soil management and seedling establishment categories was decreased, indicating that difficulties encountered by farmers in these fields were mostly solved. High congruency between economic outcome of research and allocation of resources by technology categories indicates a rational allocation of resources for research on direct-seeding of vice in RDA.

• Journal of Fisheries and Marine Sciences Education
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• v.13 no.2
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• pp.146-167
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• 2001

Korea and China are two opposite countries located aside Yellow Sea and co-utilize the East China Sea. The two countries are close together from geological point of view, however, the competitive development of resources was more emphasized than the cooperative development of resources between the two countries because the special policy relationship. Additionally, after the communist government of China was founded in 1949, the political conception between the two countries was quite different. Therefore the establishment of appropriate international fisheries co-operation was impossible, and the international management problems of fisheries resources in Yellow Sea and East China Sea were let alone. UN convention on the Law of the Sea came to force in 1994, Korea and China adopted the exclusive economic zone system in 1996. On the other hand, Fisheries Law in Korea was enacted in 1953 in order to management of fisheries resources, and also China was enacted fisheries law in 1986. The two countries control the fisheries effort through fisheries license system, meanwhile through prohibition fishing area, prohibition fishing period, limitation of net size, and limitation of body length to conserve and manage the fisheries resource. The serious management methods of resource management in the two countries are similar such as the creation of promptly decreased species and those species that have commercial value, discharge of fish seedling stock, settlement of artificial reef and clean of fishing ground. Therefore, the two countries should consider not only the improvement of formal law system, but also how to recover the fisheries resources in circumference water zone and how to improve the efficiency of fisheries resource management. Specially the settlement and management of artificial reef should be chosen in the area that have the highest benefit to two countries, and should establish the common management system of discharge of fish seedling stock. And the two countries should adopt the same criteria through technical management and limitation of net size, limitation of body length, and prohibition area of special fisheries to ensure the highest fisheries benefit of fisherman in the two countries and the highest efficiency of fisheries resource management.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.151-151
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• 2017

In Asia, rice production has some difficulties with reduction of farm household population and increase of elderly population. As a result, it has resulted in inefficiency and we needs to reduce labor force and improve labor productivity. Direct-seeding in rice could reduce labor and production costs, the area of direct seeding is increasing in japonica rice production in Asia. In direct seedling cultivation competition against weeds is one of most important concern. So, low temperature germinability and mesocotyl elongation should be considered. In this study, we evaluated the mesocotyl length and low temperature germination conducted association analysis using 137 korea core collections. An average length of mesocotyl among 137 core collections was skewed range from 0mm to 43mm. we searched candidate gene around target SNP. Such related traits, genome-wide association study (GWAS) analysis was carried out using GAPIT. Also, average mesocotyl length of 394 korea landrace cultivars was measured ranging from minimum 0 mm to maximum 34mm. 30 out of 394 Korea landrace cultivar conducted re-sequencing, and haplotype analysis of candidate gene. we searched these related resources, which including germination of low temperature and mesocotyl elongation. This could be used for the development of direct-seeding cultivars. The valiated accession of core collection and landrace cultivars will be used development of direct-seedling cultivar in the future.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.2
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• pp.108-113
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• 2014

This study was conducted to evaluate the performance of Italian ryegrass cultivars for salt tolerance under in vitro condition. Italian ryegrass cultivars such as Greenfarm, Florida80, Kowinearly, and Hwasan101 were tested for their tolerance to various sodium chloride levels (0, 50, 150, 250, and 350 mM). The seed germination, growth, and activities of antioxidant enzymes were investigated under salt treatment. Physiological traits such as seed germination percentage, germination period, shoot and root length, and dry weight were suppressed under entire salt stress conditions. The results indicated that the highest germination percentage and shoot and root length were recorded at normal conditions. Increased sodium chloride levels caused a significant reduction in the seed germination and growth rate. Among the four tested cultivars, Italian ryegrass 'Hwasan101' could be considered as salt tolerant owing to its higher germination percentage, better seedling growth and antioxidant activities under salinity stress, whereas Greenfarm cultivar was more sensitive. The selection of Italian ryegrass cultivars for greater tolerance to saline environment would allow greater productivity from large saline lands.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.358-362
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• 2009

A New Cymbidium variety "Yellow Evening" was developed from a cross between "Oji" and "Valley Flower Cherry Life" followed by seedling and line selections at the National Institute of Horticultural and Herbal Science (NIHHS), Rural Development Administration (RDA) in 2004. After investigation of the characteristics and selection for 9 years (1996-2004), it has been selected specifically pot orchid flower. "Yellow Evening" has medium plant height and semi-erect peduncle. It has medium flowering habit and brownish yellow flowers (RHS, Y11B: petal and sepal) with grayed purple GP183A) spot on lip, when fully opened. Each peduncle has 15.3 flowers with diameter of about 7.4 cm. It has adequate peduncle height, with some curved and spreading petal and sepals. Under optical culture conditions, it started to bloom early-winter (November).

• Journal of Aquaculture
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• v.21 no.4
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• pp.272-277
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• 2008

We investigated the growth and survival in seedling production, and growth performance was compared with the different rearing tanks and protein source of formulated feed for juvenile Pacific bluefin tuna Thunnus orientalis (PBT). The survival rate at the end of nursery culture at 30 days after hatching was $0.69{\pm}0.40%$, and total length and mean body weight were $49.83{\pm}2.52\;mm$ and $1.03{\pm}0.09\;g$, respectively. Growth performance has no significant difference in fish reared by different tanks forms for 10 days. In order to develop an artificial diet, we evaluated the dietary utility of enzyme treated fish meal (Bio-CP, BIO) for juvenile PBT. Only diet BIO sustained similar growth and higher feed efficiency, and final carcass lipid content as compared to those of Sand lance (SL) These results revealed that BIO-CP a suitable dietary protein source, could sustain growth of PBT.