• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.4
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• pp.67-76
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• 2021

Biogasification is a technology that produces environmentally friendly fuel using methane gas generated in the process of stably decomposing and processing organic waste. Biogasification is the most used method for energy conversion of organic waste with high moisture content, and is a useful method for organic waste treatment following the prohibition of direct landfill (2005) and marine dumping (2013). Due to African Swine Fever (ASF), which recently occurred in Korea, recycling of wet feed is prohibited, and consumers such as dry feed and compost are negatively recognized, making it difficult to treat food waste. Accordingly, biogasification is attracting more attention for the treatment and recycling of food waste. Korea's energy consumption amounted to 268.41 106toe, ranking 9th in the world. However, it is an energy-poor country that depends on foreign imports for about 95.8% of its energy supply. Therefore, in Korea, the Renewable Energy Portfolio Standard (RPS) is being introduced. The domestic RPS system sets the weight of the new and renewable energy certificate (REC, Renewable energy certificate) of waste energy lower than that of other renewable energy. Therefore, an additional incentive system is required for the activation of waste-to-energy. In this study, the operation of an anaerobic digester that treats food waste, food waste Leachate and various organic wastes was confirmed. It was intended to be used as basic data for preparing the waste-to-energy incentive system through precise monitoring for a certain period of time. Four sites that produce biogas from organic waste and use them for power generation and heavy gas were selected as target facilities, and field surveys and sampling were conducted. Basic properties analysis was performed on the influent sample of organic waste and the effluent sample according to the treatment process. As a result of the analysis of the properties, the total solids of the digester influent was an average of 12.11%, and the volatile solids of the total solids were confirmed to be 85.86%. BOD and CODcr removal rates were 60.8% and 64.8%. The volatile fatty acids in the influent averaged 55,716 mg/L. It can be confirmed that most of the volatile fatty acids were decomposed and removed with an average reduction rate of 92.3% after anaerobic digestion.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.229-236
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• 2022

This study was conducted to evaluate the efficacy of adding the microbial inoculants to silage for reducing mycotoxins in rice straw silage. When a single agent of L. plantarum and a mixed agent of L. plantarum and S. cerevisiae were added in rice straw silage contaminated mycotoxins, it had an effect on silage fermentation and fiber degradation as well as mycotoxin reduction. Among the mycotoxins, only ochratoxin A and zearalenone were found in the test sample. Ochratoxin A and zearalenone showed a decreasing trend with the addition of silage inoculants compared to the control groups (38.11±2.22 and 633.67±50.30 ㎍/kg), and there was a significant difference at the mixed agents; 27.78±2.28 and 392.72±25.04 ㎍/kg, respectively (p<0.05). The pH was lower in the single agent and the mixed agent compared to the control (p<0.05). The concentration of lactic acid was higher in the single agent (11.73±0.31 mM) than in the control group (8.18±0.93 mM), and the highest concentration was 16.01±0.88 mM in the mixed agent (p<0.05). Acetic acid and propionic acid were found to be significantly lowered with the addition of silage inoculants (p<0.05). Total VFA was also lower at the addition of silage inoculants than the control group (p<0.05). The rumen in situ dry matter degradation of NDF and ADF was maintained at the highest levels of the mixed agent during the culture period, followed by the single agent and the control group at the lowest level. NDF and ADF degradation showed a significant difference at all time points after 12 and 24 hours of culture, respectively (p<0.05). The study results showed that the silage inoculants had the positive effects on quality increasing of rice straw silage; fermentative charateristics, fiber degradation and mycotoxins reduction. Ochratoxin A and zearalenone were greater reduction by adding bacterial inoculants of silage. Therefore it is considered that L. plantarum and S. cerevisiae will improve the quality and stability with remediation of mycotoxin in silage.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.603-614
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• 2022

This study investigated the characteristics of fish communities in the Bangtaecheon Stream in Korea from April to October 2020. The survey collected 4,640 fish of 26 species in 9 families from 11 survey stations. The dominant and subdominant species were Rhynchocypris kumgangensis(relative abundance at 31.5%) and Zacco koreanus(27.8%), respectively. The next most abundant species were Ladislavia taczanowskii(15.9%), Pungtungia herzi(4.0%), Brachymystax lenok tsinlingensis(3.7%), Microphysogobio longidorsalis(2.4%), and Zacco platypus(2.3%). Among the collected fish species, 17 (65.4%) were Korean endemic species, 4 (15.4%), including Acheilognathus signifer, Pseudopungtungia tenuicorpa, Gobiobotia brevibarba, and B. l. tsinlingensis,were class II endangered wildlife as designated by the Ministry of Environment, and 1 species, Hemibarbus mylodon, was a natural monument. Moreover, two landlocked species (B. l. tsinlingensisand C. koreanus) were also collected. Additionally, four cold-water species (R. kumgangensis, L. taczanowskii, B. l. tsinlingensis,and Cottus koreanus) were collected, and all of them mainly inhabited the upper and middle streams. Fish community analysis showed a tendency for dominance and uniformity to decrease and abundance and diversity to increase from upstream to downstream and that the community structure was divided into upstream and downstream groups. The river health was rated as excellent (9 stations) and good (2 stations). Compared to the previous studies, three species (Carassius auratus, Leiocassis ussuriensis,and Siniperca scherzeri) appeared in the past but did not appear in this survey, and three species (Opsariichthys uncirostris amurensis, Microphysogobio yaluensis,and Orthrias nudus) that did not appear in the past appeared in this survey. Bangtaecheon Steam is well-preserved, and climate-sensitive species, endangered wildlife, and natural monuments inhabit the stream. Therefore, continuous attention and systematic conservation measures are required.

• Journal of Korea Water Resources Association
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• v.56 no.11
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• pp.775-784
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• 2023

With the increasing trend of extreme rainfall that exceeds the design frequency of man-made structures due to extreme weather, it is necessary to review the safety of agricultural reservoirs designed in the past. However, there are no local government-managed reservoirs (13,685) that can be discharged in an emergency, except for reservoirs over a certain size under the jurisdiction of the Korea Rural Affairs Corporation. In this case, it is important to quickly deploy a mobile siphon to the site for preliminary discharge, and this study evaluated the applicability of a mobile siphon with a diameter of 200 mm, a minimum water level difference of 6 m, 420 (m²/h), and 10,000 (m²/day), which can perform both preliminary and emergency discharge functions, to the Yugum Reservoir in Gyeongju City. The test bed, Yugum Reservoir, is a facility that was completed in 1945 and has been in use for about 78 years. According to the hydrological stability analysis, the lowest height of the current dam crest section is 27.15 (EL.m), which is 0.29m lower than the reviewed flood level of 27.44 (EL.m), indicating that there is a possibility of lunar flow through the embankment, and the headroom is insufficient by 1.72 m, so it was reviewed as not securing hydrological safety. The water level-volume curve was arbitrarily derived because it was difficult to clearly establish the water level-flow relationship curve of the reservoir since the water level-flow measurement was not carried out regularly, and based on the derived curve, the algorithm for operating small and medium-sized old reservoirs was developed to consider the pre-discharge time, the amount of spillway discharge, and to predict the reservoir lunar flow time according to the flood volume by frequency, thereby securing evacuation time in advance and reducing the risk of collapse. Based on one row of 200 mm diameter mobile siphons, the optimal pre-discharge time to secure evacuation time (about 1 hour) while maintaining 80% of the upper limit water level (about 30,000 m²) during a 30-year flood was analyzed to be 12 hours earlier. If the pre-discharge technology utilizing siphons for small and medium-sized old reservoirs and the algorithm for reservoir operation are implemented in advance in case of abnormal weather and the decision-making of managers is supported, it is possible to secure the safety of residents in the risk area of reservoir collapse, resolve the anxiety of residents through the establishment of a support system for evacuating residents, and reduce risk factors by providing risk avoidance measures in the event of a reservoir risk situation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.4
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• pp.158-164
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• 2006

Yongdam Lake is the fifth largest artificial lake in Korea newly formed by the first impounding the Yongdam Multi-purpose Dam on December, 2002. Yongdam Lake, with her total water storage of 820 million M/T, is located at the roof-top region of the streams flowing into the just-constructed new Saemankeum Lake. Seasonal succession of phytoplakton in Yongdam Lake might affect cyanobacterial blooms in Saemankeum Lake by inoculating seasonal dominants. During 2002-2003 when the first impounding after the construction of Yongdam Multi-purpose Dam was still undergoing, summer cyanobacterial blooms by Anabaena, Microcystis, and Aphanizomenon were observed. Among these three, filamentous Anabaena is well known to have its species with $N_2-fixing$ ability and special cells such as heterocysts and akinetes as well as the vegetative cells. We established a clonal culture of Anabaena spiroides v. crasse (KNU-YD0310) from the live water samples collected at the bloom site of Yongdam Lake. The N- and P-nutrient requirement of the KNU-YD0310 was explored by the experimental cultivation of the laboratory strain. Ratio of heterocysts to vegetative cells increased as N-deficiency extended with its maximum at $N_2-fixing$ condition. The strain KNU-YD0310 exhibited considerable growth under N-limiting conditions while its growth was proportional to the initial phosphate-P concentration under P-deficient conditions. Under P-limiting conditions akinete density increased, which could be interpreted as an adaptation strategy to survive severe environment by transforming into resting stage. The above eco-physiological characteristics of Anabaena spiroides v. crassa might be useful as an ecological criterion in controlling cyanobacterial blooms at Shaemankeum Lake in near future.

• The Korean Journal of Air & Space Law and Policy
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• v.18
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• pp.135-183
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• 2003

Aerospace force is a determining factor in a modem war. The combat field is expanding to space. Thus, the legitimacy of establishing aerospace force is no longer an debating issue, but "how should we establish aerospace force" has become an issue to the military. The standard limiting on the military use of space should be non-aggressive use as asserted by the U.S., rather than non-military use as asserted by the former Soviet Union. The former Soviet Union's argument is not even strongly supported by the current Russia government, and realistically is hard to be applied. Thus, the multi-purpose satellite used for military surveillance or a commercial satellite employed for military communication are allowed under the U.S. principle of peaceful use of space. In this regard, Air Force may be free to develop a military surveillance satellite and a communication satellite with civilian research institute. Although MTCR, entered into with the U.S., restricts the development of space-launching vehicle for the export purpose, the development of space-launching vehicle by the Korea Air Force or Korea Aerospace Research Institute is beyond the scope of application of MTCR, and Air Force may just operate a satellite in the orbit for the military purpose. The primary task for multi-purpose satellite is a remote sensing; SAR sensor with high resolution is mainly employed for military use. Therefore, a system that enables Air Force, the Korea Aerospace Research Institute, and Agency for Defense Development to conduct joint-research and development should be instituted. U.S. Air Force has dismantled its own space-launching vehicle step by step, and, instead, has increased using private space launching vehicle. In addition, Military communication has been operated separately from civil communication services or broadcasting services due to the special circumstances unique to the military setting. However, joint-operation of communication facility by the military and civil users is preferred because this reduces financial burden resulting from separate operation of military satellite. During the Gulf War, U.S. armed forces employed commercial satellites for its military communication. Korea's participation in space technology research is a little bit behind in time, considering its economic scale. In terms of budget, Korea is to spend 5 trillion won for 15 years for the space activities. However, Japan has 2 trillion won annul budget for the same activities. Because the development of space industry during initial fostering period does not apply to profit-making business, government supports are inevitable. All space development programs of other foreign countries are entirely supported by each government, and, only recently, private industry started participating in limited area such as a communication satellite and broadcasting satellite, Particularly, Korea's space industry is in an infant stage, which largely demands government supports. Government support should be in the form of investment or financial contribution, rather than in the form of loan or borrowing. Compared to other advanced countries in space industry, Korea needs more budget and professional research staff. Naturally, for the efficient and systemic space development and for the prevention of overlapping and distraction of power, it is necessary to enact space-related statutes, which would provide dear vision for the Korea space development. Furthermore, the fact that a variety of departments are running their own space development program requires a centralized and single space-industry development system. Prior to discussing how to coordinate or integrate space programs between Agency for Defense Development and the Korea Aerospace Research Institute, it is a prerequisite to establish, namely, "Space Operations Center"in the Air Force, which would determine policy and strategy in operating space forces. For the establishment of "Space Operations Center," policy determinations by the Ministry of National Defense and the Joint Chief of Staff are required. Especially, space surveillance system through using a military surveillance satellite and communication satellite, which would lay foundation for independent defense, shall be established with reference to Japan's space force plan. In order to resolve issues related to MTCR, Air Force would use space-launching vehicle of the Korea Aerospace Research Institute. Moreover, defense budge should be appropriated for using multi-purpose satellite and communication satellite. The Ministry of National Defense needs to appropriate 2.5 trillion won budget for space operations, which amounts to Japan's surveillance satellite operating budges.

• Journal of Hospice and Palliative Care
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• v.9 no.1
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• pp.17-29
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• 2006

Purpose: This research aimed to investigate the actual condition and satisfaction of volunteer activity in Australian hospital. Methods: Data was collected by self reported questionnaire from 101 volunteers and analyzed by frequency and percentage, t-test, ANOVA and Sheffe and Pearson's correlation coefficients using SPSS 12.0. Results: 1. Years involved in volunteer work were $5{\sim}10$ years (32.7%), above 10 years (30.7%), $2{\sim}3$ years (11.9%) and $3{\sim}5$ years (10.9%). Types of volunteer work were physical care (32.7%), physical and emotional care (14.9%), and others (18.8%). Types of allocation of tasks were by volunteer coordination (55.7%), and by volunteer preference and consent between volunteer and coordinator (both respectively, 20.5%). Main reasons for volunteer work were to help sick people (61.4%) and to make good use of leisure time (22.8%). Routes to start volunteer work were from his (her) own inquiries (43.4%), from hearing from other volunteers (30.7%) and from mass media (13.1%). 80.2% of volunteers had received some kinds of training or preparation for volunteer work. Suitability of volunteer's skill and ability to voluntary work were 'very well' (74.0%) and 'mostly well' (18.0%). Reimbursements or benefits received for volunteer work were token or lunch or group outing (31.7%), and token and lunch or group outing (19.8%). Evaluation frequency for volunteer work was occasionally (372%), frequently (30.9%), always (17.0%) and never (14.9%). Relationship with volunteer work coordinator was very good (85.0%). The relationship with other volunteers was very good (81.2%). The relationship with hospital staffs was very good (69.7%) and mostly good (21.2%). Family and friend's support for volunteer work was very good (83.2%). 2 The mean score of satisfaction for the hospital volunteer activity was $3.09{\pm}0.49\;(range:\;1{\sim}4)$. The highest score domain was 'social contact', $3.48{\pm}0.61$, and the lowest was 'social exchange', $1.65{\pm}0.63$. An item of the highest score was 'I have an opportunity to help other people' ($3.83{\pm}0.40$), and the lowest score item was 'I will receive compensation for volunteer work I have done ($1.10{\pm}0.78$).' 3. The satisfaction from hospital volunteer activity was shown by significant difference according to sex (t=2.038, P=0.044), marital status (F=3.806, P=0.013), years involved in volunteer work (F=3.326), nam reason to do volunteer work (F=2.707, P=0.035), receive any training or preparation for volunteer work (t=-1.982, 0=0.050), frequency of evaluation for volunteer work (F=7.877, P=0.000), suitability of volunteer's skill and ability to voluntary work (t=2.712, P=0.049), relationship with volunteer work coordinators (F=-2.517, P=0.013), relation with hospital staffs (F=5.202, P=0.007), and support of their volunteer work by their family and friends (t=-3.394, P=0.001). Conclusion: The satisfaction of hospice volunteer activity was moderate. The satisfaction for hospice volunteer activity was shown by significant difference according to sex (t=2.038, P=0.044), marital status (F=3.806, P=0.013), years involved in volunteer work (F=3.326), main reason to do volunteer work (F=2.707, P=0.035), receive any training or preparation for volunteer work (t=-1.982, 0=0.050), frequency of evaluation for volunteer work (F=7.877, P=0.000), suitability of volunteer's skill and ability to voluntary work (t=2.712, P=0.049), relationship with volunteer work coordinator (F=-2.517, P=0.013), relation with hospital staffs (F=5.202, P=0.007), and family and friend's support for volunteer work (t=-3.394, P=0.001). Therefore, it is necessary to consider various factors to improve the satisfaction of voluntary work.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.5
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• pp.407-428
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• 1991

The eastern coastal area having variability of climate is located within Taebaek mountain range and the east coast of Korea. It is therefore ease to cause the wind damages in paddy field during rice growing season. The wind damages to rice plant in this area were mainly caused by the Fohn wind (dry and hot wind) blowing over the Taebaek mountain range and the cold humid wind from the coast. The dry wind cause such as the white head, broken leaves, cut-leaves, dried leaves, shattering of grain, glume discolouration and lodging, On the other hand the cold humid wind derived from Ootsuku air mass in summer cause such symptom as the poor rice growth, degeneration of rachis brenches and poor ripening. To minimize the wind damages and utilize as a preparatory data for wind injury of rice in future, several experiments such as the selection of wind resistant variety to wind damage, determination of optimum transplanting date, improvement of fertilizer application methods, improvement of soils and effect of wind break net were carried out for 8 years from 1982 to 1989 in the eastern coastal area. The results obtained are summarized as follows. 1. According to available statisical data from Korean meteorological services (1954-1989) it is apperent that cold humid winds frequently cause damage to rice fields from August 10th to September 10th, it is therefore advisable to plan rice cultivation in such a way that the heading date should not be later than August 10th. 2. During the rice production season, two winds cause severe damage to the rice fields in eastern coastal area of Korea. One is the Fohn winds blowing over the Taebaek mountain range and the other is the cold humid wind form the coast. The frequency of occurrence of each wind was 25%. 3. To avoid damage caused by typhoon winds three different varieties of rice were planted at various areas. 4. In the eastern coastal area of Korea, the optimum ripening temperature for rice was about 22.2$^{\circ}C$ and the optimum heading date wad August 10th. The optimum transplanting time for the earily maturity variety was June 10th., medium maturity variety was May 20th and that of late maturity was May 10th by means of growing days degree (GDD) from transplanting date to heading date. 5.38% of this coastal area is sandy loamy soil while 28% is high humus soil. These soil types are very poor for rice cultivation. In this coastal area, the water table is high, the drainage is poor and the water temperature is low. The low water temperature makes it difficult for urea to dissolve, as a result rice growth was delayed, and the rice plant became sterile. But over application of urea resulted in blast disease in rice plants. It is therefore advise that Ammonium sulphate is used in this area instead of urea. 6. The low temperature of the soil inhibits activities of microorganism for phosphorus utilization so the rice plant could not easily absorb the phosphorus in the soil. Therefore phosphorus should be applied in splits from transplanting to panicle initiation rather than based application. 7. Wind damage was severe in the sandy loamy soil as compared to clay soils. With the application of silicate. compost and soil from mointain area. the sand loamy soil was improved for rice grain colour and ripening. 8. The use of wind break nets created a mocro-climate such as increased air. soil and water temperature as well as the reduction of wind velocity by 30%. This hastened rice growth, reduced white head and glume discolouration. improved rice quality and increased yield. 9. Two meter high wind break net was used around the rice experimental fields and the top of it. The material was polyethylene sheets. The optimum spacing was 0.5Cm x 0.5Cm. and that of setting up the wind break net was before panicle initiation. With this set up, the field was avoided off th cold humid wind and the Fohn. The yield in the treatment was 20% higher than the control. 10. After typhoon, paddy field was irrigated deeply and water was sprayed to reduce white head, glume discolouration, so rice yield was increased because of increasing ripening ratio and 1, 000 grain weight.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.371-384
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• 1982

Highly cold tolerant varieties are requested not only at high latitute cool area but also tropical high elevated areas, and the required tolerance is different from location to location. IRRI identified 6 different types of cold tolerance required in the world for breeding purpose; a) Hokkaido type, b) Suweon type, c) Taipei 1st season type, d) Taipei 2nd season type, e) Tropical alpine type and, f) Bangladesh type. The cold tolerance requested in Korea is more eargent in Tongil group cultivars and their required tolerance is the one such as the physiological activities at low temperature are as active as in Japonica group cultivars at least during young seedling stage and reproduction stage. With conventional Japonica cultivars, such cold tolerant characters are requested as short growth duration but stable basic vegetative growth, less sensitive to high temperature and less prolonged growth duration at low temperature. The methods screening for cold tolerance were developed rapidly after the Tongil cultivar was reliesed. The facilities of screening for cold tolerance, such as, low temperature incubator, cold water tank, growth cabinet, phytotron, cold water nursery in Chuncheon, breeding nursery located in Jinbu, Unbong and Youngduk, are well established. Foreign facilities such as, cold water tank with the rapid generation advancement facilities, cold nurseries located in Banaue, Kathmandu and Kashimir may be available for the screening of some limitted breeding materials. For the reference, screening methods applied at different growth stages in Japan are introduced. The component characters of cold tolerance are not well identified, but the varietal differences in a) germinability, b) young seedling growth, c) rooting, d) tillering, e) discolation, f) nutrition uptake, g) photosynthesis rate, h) delay in heading, i) pollen sterility, and j) grain fertility at low temperature are reported to be distinguishable. Relationships among those traits are not consistent. Reported studies on the inheritance of cold tolerance are summarized. Four or more genes are controlling low temperature germinability, one or several genes are controlling seedling tolerance, and four or more genes are responsible for the pollen fertility of the rice treated with cold air or grown in the cold water nursery. But most of those data indicate that the results may come out in different way if those were tested at different temperature. Many cold tolerant parents among Japonicas, Indicas and Javanicas were identified as the results of the improvement of cold tolerance screening techniques and IRTP efforts and they are ready to be utilized. Considering a) diversification of germ plasm, b) integration of resistances to diseases and insects, c) identification of adaptability of recommending cultivars and, d) systematic control of recommending cultivars, breeding strategies for short term and long term are suggested. For short term, efforts will be concentrated mainly to the conventional cultivar group. Domestic cultivars will be used as foundation stock and ecologically different foreign introductions such as from Hokkaido, China or from Taiwan, will be used as cross parents for the adjustment of growth durations and synthsize the prototype of tolerances. While at the other side, extreme early waxy Japonicas will be crossed with the Indica parents which are identified for their resistances to the diseases and insects. Through the back corsses to waxy Japonicas, those Indica resistances will be transfered to the Japonicas and these will be utilized to the crosses for the improvement of resistances of prototype. For the long term, efforts will be payed to synthsize all the available tolerances identified any from Japonicas, Indicas and Javanicas to diversify the germ plasm. The tolerant cultivars newly synthsized, should be stable and affected minimum. to the low temperature at all the growing stages. The resistances to the diseases and insects should be integrated also. The rapid generation advancement, pollen culture and international cooperations were emphasized to maximize the breeding efficiency.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.18
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• pp.124-155
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• 1975

To obtain the fundamental informations on the varietal improvement of peanut and to study the ecological variations of the important agronomic traits and to the relationship between the traits studied, an investigation was made on varietal classification of 489 introduced on the basis of their morphological and ecological differences at Crop Experiment Station, Suweon in 1968, and the other study conducted at some location as above in 1969 was to investigate the ecological variations of the materials in accordance with changes of seeding date using classified varietal group under 5 different seeding times from April 16 to July 7 with twenty days interval. The results obtained were summarized as follows: 1. Peanut varieties tested were classified into Spanish, Virginia Erect, Virginia Runner, Southeast Runner. Valencia and Semirunner, on the basis of plant type, flowering time, number of grains per pod and grain size. 2. Characteristics of varietal group classified are as followings. (1) Spanish; erect, small grained and early maturing type. (2) Virginia Erect; erect, large grained and late flowering type. (3) Virginia Runner; runner, large grained and late maturing type. (4) Southeast Runner; runner, small grained and early maturing type. (5) Valencia; erect, small grained and early flowering type with 3-4 grains per pod. (6) Semi runner; semirunner, large grained and late flowering type. 3. Flowering period in respective varietal group was consistently shorted by delayed seeding date and the degree of shortening was more serious in late flowering varietal group. 4. Number of branches per plant was generally decreased in late seeding date in respective group. However, Spanish and Virginia Runner exhibited lower number of branches in the first seeding rather than the second seeding and the lowest number of branches was found in Spanish while the highest were Virginia Erect in all seeding date. 5. Shelling ratio was high in Spanish and Southeast Runner in any seeding date and decreased remarkedly by seeding after May. 6. Number of pod per plant in all varietal groups was remarkedly decreased by delayed seeding date and the degree of decreasing was more serious in large grain varietal group. 7. The higher pod weight per plant was found in second seeding date rather than first seeding and pod weight per plant was decreased obviously in all late seeding after the second. Therefore, among the cultivars tested, Southeast Runner noted the highest pod weight per plant while Virginia Runner showed the lowest. 8. Grain number per plant expressed the similar tendency as the pod weight per plant but was low in large grain group and high in small grain group in all seeding date employed. 9. 100 grain weight was heaviest in second seeding and was decreased remarkedly after the second and even the first seeding date. 10. Yield per 10a noted considerable variations in accordance with seeding date in all groups classified. However, the yield was increased in second seeding date (May 7) and decreased in the others. 11. Length of main stem and branches were exceptionally decreased in the first seeding date compare to the second in Spanish while other varieties were tend to be same between the indicated seeding date, but. these two traits were strikingly decreased in all seeding after the second. This tendency, however, strongly suggested the importance of environmental effects on peanut growth in terms of their changes due to the different seeding date. 12. Highly significant positive correlations were showed between yield and yield componets such as pod weight per plant, 100 grain weight and the number of grains per plant in all varietal groups except, Virginia Runner. However, the other characters were almost not correlated with yield and differences in correlation coefficients among the seeding dates were found. 13. Path coefficients estimated for yield components to yield was higher in number of grains per plant pod weight per plant and 100 grain weight in terms of direct effect and the other components were negligible in all varietal groups. 14. Heritabilities estimated were generally high in pod number per plant, shelling ratio, 100 grain weights and number of grains per pod and the other traits were relatively low.