• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.26-31
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• 1978

The objective of the present study was to investigate the effect of nicotine-contaminated mulberry-leaf, which was grown in the vicinity of tobacco drying plant (TDP), on cocoon crop. Mulberry-leaf harvested from the field at Sericultural Experiment Station (SES), Suweon, Korea, was used as control, supposedly nicotine-free leaf. Leaf harvested from the field in the distances of 30-50m, 300-400m and 700-800m from TDP was fed during the whole larval stage of the silkworm at. SES. The effect of leaf in each treatment level on the quantitative characters of the silkworm was summarized as follows; 1. Larval duration from 4th instar on was significantly longer in the TDP-leaf treatments than for the control. 2. Duration of matured silkworm appearance became longer as the distance of the mulberry-field from TDP got shorter, because the larval duration and growth of the silkworm were not uniform in the TDP-leaf treatments. 3. Mortality rates during the late larval, cocoon spinning, and pupal stages were highest for the 30-50m leaf, especially mortality rates during the late larval and pupal stage were serious. 4. Pupation rate was lowest for the 30-50m leaf and those for the 300-400m and the 700-800m leaf were not significantly different from that of the control. 5. Nicotine damage to cocoon weight and cocoon shell weight was significant in each TDP-leaf level. Cocoon shell ratio was reduced at the same extent in each level, compared with the control. 6. The ratio among cocoon-classes was significantly different between treatments, compared with best-cocoon ratio of 87.1% for the control. Cocoons were not uniform for the 30-50m leaf, and those for the 300-400m and the 700-800m leaf were as almost uniform as those for the control. 7. Loss of fresh cocoon yield became greater as the distance of the mulberry-field from the TDP-got shorter. In conclusion, the critical distance of mulberry-field, which influences larval health, cocoon quality and yield, appeared to be 800m from the TDP. Such other factors as wind direction and topographic location may be involved in the critical distance. 8. From the present experiment, we could obtain only the effect of nicotine on the silkworm through digestive system, since the silkworm was raised at SES in Suweon. If the silkworm.. were raised in the vicinity of the TDP, poison effect of nicotine on the silkworm could beo expected through exoskeleton and tracheal system as well as through digestive system.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1559-1572
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• 2021

The response of vegetation under the crop stress condition was evaluated using structural, biochemical, and physiological vegetation indices based on unmanned aerial vehicle (UAV) images and field-spectrometer data. A high concentration of herbicide was sprayed at the different growth stages of garlic to process crop stress, the above ground dry matter of garlic at experimental area (EA) decreased about 46.2~84.5% compared to that at control area. The structural vegetation indices clearly responded to these crop damages. Spectral reflectance at near-infrared wavelength consistently decreased at EA. Most biochemical vegetation indices reflected the crop stress conditions, but the meaning of physiological vegetation indices is not clear due to the effect of vinyl mulching. The difference of the decreasing ratio of vegetation indices after the herbicide spray was 2.3% averagely in the case of structural vegetation indices and 1.3~4.1% in the case of normalization-based vegetation indices. These results meant that appropriate vegetation indices should be utilized depending on the types of crop stress and the cultivation environment and the normalization-based vegetation indices measured from the different spatial scale has the minimized difference.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.601-609
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• 2021

The fructification characteristics, fruit quality, and yield of the 'Hwangsil' jujube tree were analyzed at various stages of growth age (3-8 years old) to obtain basic data for developing high-quality jujube production technology. The average height, crown area, stem diameter near the root, stem clear length, the number of the main branches, and the distance between any two main branches were 230.8 cm (224.4~247.2 cm), 3.0 m² (2.1~3.8m²), 4.8 cm (2.4~6.2 cm), 69.1 cm (46.6~78.0 cm), 12.9 (8.6~19.6), and 8.1 cm (7.4~9.0 cm), respectively. Tree age was positively correlated with the crown area, stem diameter near the root, but stem clear length negatively correlated with the number of main branches. The average number of fruits per mother bearing shoot and tree was 20.0 (14.3~26.3) and 302.8 (257.3~373.5), respectively. There was no correlation between tree age and fructification characteristics, such as the number of fruit-bearing mother shoots per the main branch, the number of fruit-bearing shoots per fruit-bearing mother shoot, and the number of fruits per fruit-bearing shoot. Since the shape of the jujube tree is constantly managed based onthe growing area and type of greenhouse where the tree grown. The average fruit weight, fruit hardness, and soluble solid content were 24.2 g (22.4~26.8 g), 28.4 N (27.3~30.0 N), and 19.0% (17.1~19.8%), respectively, with no correlation between the tree age and fruit quality. The average yield was 7.4 kg per tree (5.7~9.1 kg), with significantly high quantities were produced in six and seven years old trees.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.406-418
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• 2021

This study was conducted to evaluate optimal storage techniques for bare root plants and container seedlings of Quercus variabilis and Zelkova serrata in order to maintain high quality of seedlings until planting. Refrigerated storage treatments were given at two temperatures (-2℃ [freezing] and 2℃ [cooling]) for nine different durations (0, 15, 30, 60, 120, 180, 240, 300, and 360 days after storage). We analyzed total nonstructural carbohydrate (TNC) content and measured shoot moisture content (SMC) during the storage stage and survival rate (SR) and dry weight during the planting stage of seedlings. The TNC content and SMC of the seedlings of the two species decreased with an increase in storage duration. The TNC content of seedlings rapidly decreased after 180~240 days of storage. The TNC reduction rate in the freezing treatment was lower than that in the cooling treatment. Also, with an increase in the storage duration of the two species, the SMC reduction rate in the cooling treatment increased in comparison with that in the freezing treatment. In both the species, the SR after planting decreased rapidly after 60 days of cooling storage and 180 days of freezing storage, respectively. The SR after planting was less than 60% when the TNC content for both the species dropped below 20 mg g^-1. In addition, the SR was lower than 80% when SMC measured before storage decreased by approximately 30% and 20% for Q. variabilis and Z. serrata, respectively. Our results suggest that cooling (1~2℃) storage is recommended for a short-term period (2 months or less), whereas freezing (-2~-4℃) storage is suitable for longer periods (2~6 months). These optimal storage techniques, allied with seedling harvesting and handling systems, will improve the quality of seedling production in nursery stages and increase seedling growth performances in plantations.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.320-327
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• 2021

Freezing damage to fruit trees is frequently occurring due to cold in winter and low temperature in spring to abnormal weather caused by global warming. In particular, the freezing injury of deciduous fruit trees is highly dependent on the developmental stages of the flower buds. And the cold resistance is weakened as the growth progresses, so it is most vulnerable period from flowering to petal fall(post-bloom). Therefore, this study was conducted to analyze the cause of the freezing injury caused by severe low temperature to 'Fuji', which has a late flowering period more than 'Hongro' in April 2020. We investigated freezing injury rate in 'Fuji' and 'Hongro' apple trees damaged by natural low temperature at Boeun-gun, Chungbuk province in Korea. In addition, flower buds in the same developmental stage (tight cluster) were treated artificially low temperature to investigate the injury rate for accurate comparative analysis between varieties, and to analyze the soluble sugar and hormone contents in the flower buds. As a result of survey in natural low temperature, 'Fuji' had a higher injury rate than 'Hongro' in both orchards, and in particular, B orchard 'Fuji' had the highest injury rate of 60.5%. Also there were significantly difference in the freezing injury rate between 'Fuji' and 'Hongro' in artificially low temperature treatments. As a result of analyzing the soluble sugar contents in 'Hongro' was higher than 'Fuji'. Also ABA, IAA and SA contents were more increased in the damaged tissue than in the normal flower buds by low temperature treatments. Consequently, it was assumed that the freezing injury was closely related to soluble sugar contents in the flower buds. In particular, the freezing injury rate was negatively correlated with the sorbitol contents.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.339-349
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• 2021

In recent years, the occurrence of bacterial diseases of soybean has been increasing due to the continuous rise in spring temperature and the humid weather as a result of rain concentrated at the middle and late stages of crop growth. The resulting severe economic damage is also a concern. Unfortunately, there are no precise data on the occurrence and damage to lay the foundation for bacterial disease control in soybean in the Chungbuk Province. Therefore, the present study investigated the occurrence of major bacterial diseases, namely bacterial pustules, bacterial blight, and wildfire, in different soybean varieties in 410 fields in the Chungbuk Province in 2017. The incidence rate of bacterial pustules in the affected fields was 76.6%, and the incidence rate of infected plants was 29.3%. The incidence rate of bacterial blight in the affected fields was 13.9%, and the incidence rate of infected plants was 4.6%. The incidence rate of wildfire in the affected fields was 23.2%, and the incidence rate of infected plants was 10.1%. The overall incidence rate of bacterial diseases in the soybean fields where the diseases originated was 37.9% for bacterial pustules, 21.0% for bacterial blight, and 25.0% for wildfire, indicating that the disease incidence rate in fields where the disease originated was generally high. Among different varieties, the incidence rate of bacterial pustules was the highest in sprout soybean (88.9%), followed by Seoritae (84.0%) and Daewon (81.2%). The incidence rate of bacterial blight was the highest in the Daewon (19.6%), followed by Seoritae (15.2%) and sprout soybean (12.5%). The incidence rate of wildfire was the highest in sprout soybean (25.0%), followed by Daewon (24.7%) and Seoritae (5.4%). Meanwhile, in Uram, the incidence rate of bacterial pustules (7.1%) was the lowest, and this variety was not affected by bacterial blight or wildfire.

• Journal of Christian Education in Korea
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• v.71
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• pp.121-154
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• 2022

This study is to summarize the relationship between youth in terms of developmental psychology, university education, faith, and spirituality in order to form and improve relationships, which are major developmental tasks of youth, and to suggest Christian youth education by the elements of education. Relationships are formed when you are connected to another person and community, feel interested in each other, feel a sense of bond and belonging, and maintain a stable and satisfactory relationship. This is not skill or technology, but is related to life attitude and value, and continuous learning and training are required. Various developmental tasks in youth have something in common with relationships. Relationships positively affect the lives of young people, such as satisfaction with college life in the early stages of youth, adaptation to college life, personality, and career decision. Relationships are also very important in faith because human existence and faith are defined and formed through relationships. The relationship between the community and others plays an important role in spiritual development for the meaning of life and inner growth. In the aspects of learners and educational environment, it was suggested to understand learners with desire for relationships, the generation they live in, and the educational environment in which the relationship between young people occurs. In terms of teachers, teachers have to try to change their roles such as facilitators, guides, managers, and mentors. For the educational purpose and content, it was suggested that relationships should be the ultimate purpose and the educational content for this was presented in three different types of relationships and each main contents to be dealt with. In terms of educational method, it was proposed to select a learner-centered group learning method that induces communication and active participation of learners to cause interaction by considering other elements of education according to the content of the relationship in the cognitive, emotional, and behavioral dimensions. In the aspects of educational results and evaluation, it was proposed to confirm that what was considered during the educational planning stage was effectively carried out in actual education, to evaluate various evaluation methods, various aspects, and to summarize the evaluation results for the specific application.

• Journal of Korea Entertainment Industry Association
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• v.14 no.5
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• pp.87-102
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• 2020

The purpose of this study was to develop regional dance contents in order to receive attention from the region and re-illuminate the peacock fan, the intangible cultural property of Seocheon, Chungnam, which has been preserved in history and has been preserved in the face of rapid urbanization and modernization. The representative four series are composed of one-person dance, two-person dance, military dance, and creative dance. The titles of each piece are basic dance , male and female love dance , military dance , and finally Korean creative dance . The commonality of the four series is the traditional dance using peacock fan, and each dance showed unique emotion and atmosphere through different themes and music, costumes, and stages. It was found that the development of regional dance contents re-created reflecting the characteristics of regional cultural heritage should create an environment that can be steadily revitalized through modernization. Through this study, it was found that the intangible cultural properties, which are our traditional cultural resources, have unlimited potential to contribute to enhancing regional and national competitiveness along with the growth potential of regional differentiation. Through such research, if existing cultural resources are preserved for globalization and produced as contents that can be easily accessed by the public, various contents besides regional dance using regional unique culture can be developed and utilized.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.319-325
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• 2022

Triticale forage has the highest yield of all winter forage crops, including rye, and a cold tolerance within an average low temperature of -10℃ in January. Therefore, this study analyzed the effects of sowing and harvesting times on the feed value and functional components of triticale to optimize the use and supply of triticale as livestock fee Room temperature' can vary widely with climate, season, and time of day. In order to clearly state the conditions of the study in a manner that facilitates replication by other researchers, please consider using an approximate temperature range instead. Seeds of the triticale 'Joseong' were sown during the fall of 2021 (October 20th) and spring of 2022 (March 7th). The triticale was harvested at the following growth stages: seedling stage, booting stage, heading stage, 10 days after heading, and 20 days after heading. The moisture content of each harvested triticale was adjusted to approximately 60%, and the triticale was fermented for silage for 40 days at ambient temperature under anaerobic conditions. We measured the pH and organic acid content of each silage to determine the feed value and functional component. The lactic acid content of the triticale silage harvested at the seedling stage sown in both fall and spring (1.61%, 1.63%) was the highest among all the silages. The octacosanol content in the silages of both fall-sown and spring-sown triticale harvested at the seedling stage (0.38, 0.27 mg/ml) was the highest. Overall, the results revealed that harvesting time had a greater impact on the feed value and functional components of triticale silage than sowing time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.1
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• pp.27-33
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• 2023

Several domestically consumed sweetpotato derivatives, such as sweetpotato starch for processing raw materials, frozen and refrigerated paste, and powder are dependent on imports. This study was conducted to examine the suitability of sweetpotato cultivars of twelve varieties (powdery-type and viscous type) cultivated in paddy fields, for use in starch, chips, dried products, and beverages. The two-year average yield results of the four cultivars suitable for starch (in order of highest to lowest yield) was as follows: Gogeonmi (4,018 kg/10a); Daeyumi (3,615 kg/10a); Jinhongmi (3,426 kg/10a); Singeonmi (2,837 kg/10a). The starch content was 20.2%, 18.2%, 21.2%, and 20.6% in Daeyumi, Gogeonmi, Singeonmi, and Jinghongmi, respectively. The total amount of starch was higher in Daeyumi (730 kg/10a) and Gogeonmi (731 kg/10a) than that in Singeonmi and Jinghongmi. The yield of Pungwonmi and Shinjami were 4,443 and 3,602 kg/10a, respectively. Powdery-type sweetpotatoes (Daeyumi and Gogeonmi) showed the low decay rates of all cultivars (0.8 and 0%, respectively). The yield of the storage root formation and storage root swelling stages by water-logging treatment decreased by 16.5% and 15.4% for Pungwonmi, and by 17.2% and 10.0% for Shinjami. Drainage management of paddy fields is necessary to reduce the damage caused by water-logging. Our results suggest that cultivation of sweetpotato varieties suitable for processing raw materials in paddy fields will enable stable yields of sweetpotato with a high starch content.