• Title/Summary/Keyword: agricultural science

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반응표면분석에 의한 쇠고기 야채 쌀죽의 이화학적 및 관능적 특성 변화

  • 이용욱;금준석;은종방
    • Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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    • 2003.10a
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    • pp.167.2-168
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    • 2003
  • 현대 사회는 서구적인 식생활의 변화로 인해 조리가 간편하고 조리 시간이 짧은 즉석식품과 영양 기호식품을 동시에 충족시켜주는 음식에 대한 소비가 늘고 있는 실정이다. 또한 최근 미곡의 공급량에 비해서 소비량이 해마다 감소하여 재고미의 증가를 볼 때, 쌀의 새로운 이용방법 모색이 절실히 요망된다. 따라서 쌀의 소비촉진과 현대사회의 소비형태를 접목시켜서 쇠고기와 야채를 이용한 즉석쌀죽을 개발하고자 하였다. 쇠고기, 야채 및 쌀가루를 이용한 soup mix의 최적 배합비를 설정하기 위하여 제조조건에 따라 다르게 제조한 쇠고기 야채 쌀죽의 이화학적 및 관능적 특성에 미치는 변화를 조사하였다. 이때 야채의 배합비에 따른 이화학적 및 관능적 특성을 모니터링 하고자 반응표면분석법 (response surface methodology, RSM)을 이용하였다. 요인변수(Xn)를 쌀의 양에 대한 버섯의 비율 (X$_1$), 당근의 비율 (X$_2$), 대파의 비율 (X$_3$)로 하여 중심합성계획에 따라 17실험구로 구분하여 조리실험을 실시하였고, 반응변수(Yn)는 soup mix를 이용하여 제조한 쇠고기 야채 쌀죽의 이화학적 특성인 색도의 L*값 (Y$_1$), a*값 (Y$_2$), b*값 (Y$_3$), 점도(Y$_4$), 퍼짐성 (Y$_{5}$), 고형분 함량(Y$_{6}$), PH (Y$_{7}$)으로 하였으며 관능적 특성인 색 (Y$_{8}$), 향 (Y$_{9}$), 점성 (Y$_{10}$), 맛 (Y$_{11}$), 전체적인 기호도 (Y$_{12}$)를 종속변수로 하여 회귀분석에 이용하였다. 회귀분석에 의한 모델식의 예측에는 SAS (statistical analysis system)program을 사용하였으며, 3차원 반응표면 분석법으로 해석하였다. 야채의 배합비에 따라 제조한 쇠고기 야채 쌀죽의 물리적 특성인 색도의 L*, a*, b* 값에 대한 반응표면 회귀식의 $R^2$은 각각 0.6098(p> 0.05), 0.8803 (p <0.05), 0.6781(p> 0.05)로서 b값에 있어서 그 유의성이 5%수준에서 인정되어 b값에 미치는 영향이 크다는 것을 알 수 있었다. L*값은 63-68사이로, a*값은 0.13에서 -0.89사이를 b*값은 2-5값 사이에서 변화하여 제조한 죽의 색이 옅은 황색임을 알 수 있었다. 고형분 함량, 퍼짐성과 pH에 대한 $R^2$은 각각 0.4280, 0.5433과 0.2406임을 볼 때 버섯, 당근, 대파의 비율에 따라 제조한 쇠고기 야채 쌀죽의 고형분 함량, 퍼짐성과 pH는 설정된 범위내에서 그 유의성이 인정되지 않아 큰 영향을 미치지 않음을 알 수 있었다. 관능검사 결과, 색과 향에 대한 반응표면 회귀식의 $R^2$은 각각0.6000과 0.7825이고 P-value는 각각 0.4290과 0.0942로서 5% 수준에서 유의한 상관성이 없음을 확인할 수 있었다. 맛과 점성에 대한 $R^2$은 0.8717과 0.8068이고 P-value는 각각 0.0195 (p <0.05)와 0.0612로서 야채의 배합비에 따라 맛에 있어서 유의확률 5%수준에서 그 유의성이 인정되었으며, 전체적인 기호도에 대한 유의성은 $R^2$이 0.8463이고 P-value는 0.0344 (p <0.05)임을 볼 때, 설정된 범위내에서 야채의 배합비에 따라 제조한 쇠고기 야채 쌀죽의 맛과 기호도에 큰 영향을 미치는 것을 알 수 있었다. 그리고 최대 임계점이 버섯의 첨가량은 0.99%, 당근의 첨가량은 0.97%, 대파의 첨가량은 0.59%에서 최적 반응표면을 나타내었다. 이상의 결과로 볼 때, 야채의 배합비에 따른 맛과 전체적인 기호도에 있어서 그 유의성이 5%수준에서 모두 유의한 상관관계를 보였으며, soup mix 제조시 쌀가루 양에 대한 야채의 최적 배합비는 버섯, 당근, 대파에 있어서 각각 0.99, 0.97과 0.59%임을 알 수 있었다.

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The Study of Environmental Risk Assessment for Fluorescent Genetically Modified Silkworms (형광단백질 발현 유전자변형 누에(Bombyx mori )의 환경위해성 평가연구)

  • Kim, Hyunjung;Jung, Chuleui;Goo, Taewon;Yi, Hoonbok
    • Korean journal of applied entomology
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    • v.53 no.3
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    • pp.199-207
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    • 2014
  • It is true that the proper environmental risk assessments for many GM (Genetically Modified) insects almost have not been executed in Korea. Therefore, we tested the environmental risk assessment about GM silkworms if there is any difference between GM silkworms and non-GM silkworms by the following three measurements. First, we measured their mobility in the breeding environment conditions with food and without food. Secondly, we measured their viability at the artificial extreme environmental conditions (low and high temperature and humidity, absent/present of foods,) after escaping from their breeding environments. Thirdly, we observed the number of laying eggs and their hatchability between GM silkworms and non-GM silkworms with four different pair experiments. The mobility of GM silkworms and non-GM silkworms statistically did not differ, and the egg productivity and hatchability were not also different. The hatchability by couple of GM female silkworms and non-GM male silkworms was lower than by non-GM male and female couple between the GM silkworms and non-GM silkworms, and there was statistically different. Relatively, the viability of GM silkworms was lower than non-GM silkworms. We could not exactly test for viability of silkworms in low temperature conditions because of their hibernating. Although there was any difference in viability and hatchability between GM silkworms and non-GM silkworms, all ability of GM silkworms was lower than non-GM silkworms. Conclusively, the environmental risk of GM silkworm was relatively lower than non-GM silkworm in this study.

Characterization of Ostrinia furnacalis (Lepidoptera: Pyralidae) Occurrence Against Maize and Sorghum Varieties in a Paddy-upland Rotation Field (답전윤환 포장 내 옥수수 및 수수 품종들에 대한 조명나방 발생 특성)

  • Kim, Min Joon;Yoon, Sung-Tag;Lee, Hee-Kwon;Jo, Hyeong-Chan;Kim, Soon-Il
    • Korean journal of applied entomology
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    • v.55 no.4
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    • pp.329-336
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    • 2016
  • Occurrence of oriental corn borer, Ostrinia furnacalis, and yield in a paddy-upland rotation field for 8 maize (Eolrukchal 1, Heugjeom 2, Miheukchal, Ilmichal, Heukjinjuchal, Chalok 4, Mibaek 2, Daehakchal) and 7 sorghum (Hwanggeumchal, Anzunbaengisusu, Moktaksusu, Sodamchal, DS-202, Nampungchal, Donganme) varieties has been surveyed. In a monitoring study using a pheromone trap carried out from 15 May to 10 September, the density of O. furnacalis adults increased rapidly from about 2 weeks after maize planting and reached the highest density at mid June. After that, their density was fluctuated a little at earlier September. The number of the damaged maize and invasive pores on the stem of 2 maizes and sorghum varieties was examined. The mean number of the damaged maize per 20 plants was 19 and 18 plants, and the number of invasive pores was 1.8 and 1.4 per maize stem in Daehakchal and Mibaek 2, respectively. In a survey carried out at harvest period using 8 maize varieties, the damaged ratio was 94%, 92%, 71%, 64%, 54%, 52%, and 45% in Daehakchal, Mibaek 2, Ilmichal, Eolrukchal 1, Chalok 4, Miheukchal, and Heugjeom 2, respectively. The number of invasive pore per Ilmichal stem was 1.4 and that of the others was less than 1.0 per stem. In addition, the damaged ratio of maize ears was 50% in Ilmichal, 40% in Heukjinjuchal, 37% in Daehakchal, etc. The damage pattern of 2 sorghum varieties, Nampungchal and Donganme, by O. furnacalis larvae was steeply increased from planting to 2 months and the trend was continued up to earlier August. At this time, the mean number of damaged sorghum was 13 and 9.2 plants for Nampungchal and Donganme, and the number of invasive stem pores was 1.06 and 0.46, respectively. In another survey carried out at harvest period for 7 sorghum varieties, their damaged ratio was 95% in DS-202, 76% in Moktaksusu, 75% in Sodamchal, 67% in Nampungchal, 57% in Anzunbaengisusu, 46% in Donganme, and 34% in Hwanggeumchal. The damage of sorghum varieties was much higher and severer than that of maizes by O. furnacalis larvae. The number of invasive pores on a sorghum stem was 1.7 in DS-202, 1.4 in Moktaksusu, 1.3 in Sodamchal, 1.1 in Nampungchal, 1.0 in Anzunbaengisusu, 0.5 in Donganme, and 0.4 in Hwanggeumchal. Meanwhile, there was no distinct connection between damaging results and yields of maizes and sorghums by O. furnacalis larvae in a paddy-upland rotation field. These results from this study can be applicable for the establishment of a management strategy to control Oriental corn borer in paddy-upland rotation fields for maize and sorghum.

Association between Satisfaction with Assistive Technology Devices and Psychosocial Impact among Some Mentally or Physically Disabled Children (뇌병변 및 지체 장애아의 보조공학기기 사용 만족도와 심리사회적 영향의 관련성)

  • Jang, Kyoung-Lae;Ryu, So Yeon;Park, Jong;Han, Mi Ah
    • Journal of agricultural medicine and community health
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    • v.42 no.3
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    • pp.132-144
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    • 2017
  • Objectives: The purpose of this study was to identify the association between satisfaction with assistive technology devices and psychosocial impact among some mentally or physically disabled children. Methods: The study subjects were 120 disabled children and their primary caregivers who were using rental assistive technology devices in Gwangju and Jeollanam-Do. Data were collected by structured questionnaire composed of general characteristics of subjects, characteristics related with using assistive devices. Quebec User Evaluation of Satisfaction with assistive Technology 2.0 (QUEST 2.0) and Psychosocial Impact of Assistive Device Scale (PIADS). The statistical analysis were performed by descriptive statistics, t-test, ANOVA and Pearson's correlational analysis. Results: The total mean score for QUEST 2.0 was $4.08{\pm}0.66$ (satisfaction with devices, $4.01{\pm}0.70$; satisfaction with the assistive devices service, $4.14{\pm}0.90$) and the mean of PIADS was $1.00{\pm}0.75$ (ability, $0.99{\pm}0.78$; adaptability, $1.04{\pm}0.86$; self-respect, $0.99{\pm}0.74$). The scores of PIADS was statistically significant difference according to usage time of assistive devices. The PIADS was significantly positive correlated with QUEST 2.0 Conclusions: The mentally or physically disabled children reported that the higher level of satisfaction and the more positive impact of psychosocial aspect with assistive technology devices. It would be necessary to perform further studies for addressing the effects of assistive technology devices.

Search for the Meaning of Social Support in Korean Society (Social Support의 한국적 의미)

  • 오가실;서미혜;이선옥;김정아;오경옥;정추자;김희순
    • Journal of Korean Academy of Nursing
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    • v.24 no.2
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    • pp.264-277
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    • 1994
  • In Korea the concept of social support was first used as a research concept in nursing and has not had much application in the clinical field. Another problem is that research on social support has used a direct translation of the words “social support” into Korean as “sawhejuk jiji”. Three questions were posed to direct the re-search. 1) Is there a concept of social support in Korean society? 2) if so, what words or expressions are used to de-scribe it? 3) further, if so, how is social support structured and how does it function? In order to answer the research questions a three-step research methodology was used : The first step consisted of a literature review on re-search related to social support and on information on the background of, and the way of thinking re-lated to interpersonal relations among Korean people. The second step, which was done to identify whether there is a concept of social support in korean society, involved interviewing a sample of the population. The third step involved a panel discussion that included the members of the research team and three consultants, a sociologist, a philosopher and a scholor in korean literature. A review of the literature on interpersonal relationships in traditional korean society identified a four cirole structure that explains interpersonal relationships. The first circle with “me” at the center is the family but here “me” disappears into the “we” that is essential for a cooperative agricultural society. In the second circle are those close to “me” but outside the family. The third circle includes those with whom “I ” have infrequent but regular contact and with whom correct conduct is important. The last circle is all the people with whom “I” have nothing in common. They are excluded in interpersonal relationships. The literature on interpersonal relationships showed that within the traditional Korean society people lived in villages where most people were very familiar with each other. “Yun”, the social network established the connection and “Jung”, the feeling of affection increased with time as the connection was strengthened. In the traditional village psychological support was provided through “Mallaniki”, “Pumashi” and “Kae” with the latter two also providing material support. In modern Korea there are more informal and formal social networks, like social services and community activities on the formal level and cultural and leisure groups along with “kae’s on the informal level. But even with this modern variety of groups, most social support comes from informal networks that resemble the traditiorlal “Pumashi”, “Kai” md “Mallaniki”. The six member research team interviewed 65 people in order to identify whether there is a concept of social support and then analysed their responses. There were 20 different words describing the reception of the social support and these could be grouped into seven major categories : virtuous, fortunate, helped, supported, blessed, attached(receiving affection) and receiving (grace) benevolence. there were 27 words describing the act of social support which could be categorized into seven major categories : love, looking after, affection(attachment), kindness(goodness), faith, psychological help and material help. for the meaning of social support translated as “sawhe juk jiji” there were a total of 14 different answers which could be categorized into 3 major categories : help, agreement, and faith. In third step, the results of the literature review and the answers to the questions were discussed in a pannel. The results of the discussion led to the following definition of social support in Korea which is shaped like a the four sided pyramid on a base. Social support is the apex of the pyramid and four sides are made up of : “do-oom” (both emotional and material help), “jung” (connectedness, or relationship bound by affection, regard or shared common experience ), “midum” (faith or belief in), “eunhae” (kindness or benevolence). The research team identified “Yun”( the basic network of relationships) as the base of the pyramid and as such the foundation for the components of social support in Korean culture. On “Yun” rest the other four components of social support : “Jung”, “Midum”, “Do-oom”, and “Eunhae”, For social support to take place there must be “Yun”. This is an important factor in social support. In private social network “Jung” is an essential factor in social support. But not in the public social network. “Yun” is a condition for “Jung” and “Jung” is the manifestation of support.

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Investigation of Requirement and Demand toward for Functional Traditional Hangwa(Korean Cookies) of Tradition (기능성 전통 한과류 요구도 및 수요도 조사)

  • Bok, Hye-Ja;Choi, Soo-Keun
    • Journal of the East Asian Society of Dietary Life
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    • v.18 no.5
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    • pp.692-701
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    • 2008
  • This study was conducted with 150 adults of 20 years or older, all of whom lived in Seoul. The awareness of traditional Hangwa (Korean cookies) was shown to be relatively low, with 2.9 points on average, and the intake of traditional Hangwa for a month was 2.1 times. For the reason that traditional Hangwa couldn't become popular, and the opinion that the reason was because the price is expensive was the highest, at 3.8. The next highest reasons given were because it is difficult to buy, and because it is inconvenient to eat, at 3.0. The traditional Hangwa was shown to enjoy positive awareness as opposed to negative awareness, while the manufacturing sanitation was also recognized to be relatively clean, with 2.6 points assigned to the opinion that it doesn't taste good, and 2.7 points assigned to the opinion that the manufacturing sanitation is unclean. With regard to the excellence of traditional Hangwa, the response that 'our tradition can be handed down' was the most often encountered, with a score of 3.9. The traditional Hangwa was appraised as excellent, with 3.6 points assigned to the opinion 'it suits our body because it is made with our agricultural products' and 3.4% for each opinion 'safe ingredients are used' and 'all ingredients are good for health'. With regard to the level of agreement for the development of functional traditional Hangwa, the positive group was higher than 25.3% of the negative group, with 27.3% for 'agree very much' and 22.0% for 'agree'. When converted into a 5-point scale for the development of functional traditional Hangwa, the group that was positive toward its development was high, with 3.4 points on average. All categories of excellence awareness were correlated with the level of agreement for the development of a functional food product (p<0.001). Consumer awareness toward the addition of traditional Hangwa functionality was generally positive, with 3.3 points or higher on average, and awareness of the aging suppression and diabetes control effects of Hangwa was also high, with 3.5 points. Next were Hangwa for diet, Hangwa for blood pressure control, Hangwa for mineral supple-mentation and vitamin additive-type Hangwa, with 3.4 for each, and Hangwa for health preservation, with 3.3 in order. With regard to the degree of interest toward functional traditional Hangwa for the treatment of diseases, obese patients cited aging suppression, at 3.2, and vitamin additive Hangwa, at 3.0, while Hangwa for dieting was assigned 2.8 points. Patients with high blood pressure, blood circulation, and diabetes were all shown as having a high degree of interest in all items, while evidencing particular interest toward Hangwa for diabetes control and Hangwa for blood pressure control. With regard to intention to purchase while developing functional traditional Hangwa, the group asserting intention to purchase was higher than 60% for all items except for Hangwa for diabetes control (58.7%). The Hangwa for aging suppression was highest, at 68.6%, and shown as having intention to purchase during development in the order of vitamin additive Hangwa at 68.0%, Hangwa for mineral supplementation at 64.6%, each of Hangwa for health preservation and Hangwa for blood pressure control at 62.7%, Hangwa for diet at 62.6% and Hangwa for diabetes control at 58.7%. The considerations during the development of functional traditional Hangwa were in the following order: storage at 4.1 points, taste and level of function at 3.9 points, size at 3.5 points, and packing at 3.4 points.

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A Study on the Estimation of Ecological Footprint in Gyeongsangbuk-do for Comparison of Environmental Capacity of Each Local Government (자치단체별 환경용량 비교를 위한 경상북도지역 생태발자국 추정연구)

  • Kang, Kee-Rae;Kim, Hee-Chae;Kim, Dong-Pil;Oh, Hyun-Kyung;Cho, Kwang-Jin;Shin, Young-Ho
    • Korean Journal of Environment and Ecology
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    • v.28 no.6
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    • pp.769-778
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    • 2014
  • The rapid urbanization and increase in population due to industrialization have led to the extension of cities and the reduction in naturality as a necessity. Now, it is the biggest threat to virtuous circle of ecosystem. With the expansion of common recognition that this ecological crisis would be accompanied by the crisis of mankind, many countries all around the world are conducting researches to indicate the optimum consumption level of individual as an index in addition to cross-national environmental indicators such as ESI, EPI and SDI, by measuring environmental consumption of state, local government or individual, and comparing each region. Based on this background, this research was carried out to estimate the environmental capacity of 23 local government in Gyeongsangbuk-do. The result of EF estimation showed that EF value necessary for life per head in Gyeongsangbuk-do was 0.9534, and it showed an ecological deficit of 25.3 percent when analyzing it in consideration of the ecological capacity. Also, among the local governments in Gyeongsangbuk-do, Youngduk-gun displayed the highest EF, and Ulleung-gun displayed the lowest EF. But when analyzing the ecological deficit in consideration of the ecological capacity of each region, Gumi-city showed the greatest ecological deficit, and Youngyang-gun showed the biggest ecological capacity. The environmental capacity estimated in this study is to digitize the ecological capacity and ecological deficit of each local government in Gyeongsangbuk-do. The estimated optimum environmental capacity of each local government suggests the scale of environmental preservation and proper development and furthermore, could be used as fundamental data for persuading members of each local government when selecting a location of development facility or preservation area.

Sequential Sampling Plan for Aphis gossypii (Hemiptera: Aphididae) based on Its Intra-plant Distribution Patterns in Greenhouse Cucumber at Different Growth Stages (온실재배 오이의 생육단계별 목화진딧물의 주내 분포 특성에 기초한 축차표본조사법)

  • Chung, Bu-Keun;Song, Jeong-Heub;Lee, Heung-Su;Choi, Byeong-Ryul
    • Korean journal of applied entomology
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    • v.54 no.4
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    • pp.401-407
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    • 2015
  • This study describes the development of a method for monitoring Aphis gossypii in greenhouse cucumber fields that was used during 2013 and 2014. The dispersion pattern of A. gossypii was determined by commonly used methods: Taylor's power law (TPL) and Iwao's patchiness regression (IPR). The sample unit was determined by linear regression analysis between mean density of sample unit versus whole plant. The optimum sample unit for different plant growth stages was two leaves (median and the lowest + 1 leaf) when the total number of leaves was less than nine, and three leaves (4th, 7th from canopy, and the lowest +1 leaf) when the total number of leaves was greater than nine. A. gossypii showed an aggregated distribution pattern, as the slopes of both TPL and IPR lines were greater than 1. TPL provided a better description of the mean-variance relationship than did IPR. The slopes and intercepts of TPL and IPR from leaf samples did not differ between the surveyed years. Fixed precision levels (D) for a sequential sampling plan were developed using Green's and Kuno's equations based on the number of aphid in a leaf sample. Green's method was more efficient than Kuno's to stop sampling. The number of samples needed to estimate the density of A. gossypii increased at higher D levels and lower mean densities. The cumulative number of aphids needed to stop sampling increased at higher D levels and with fewer plants sampled. Thus to estimate 10 aphids per leaf, 13 plants needed to be sampled, and the cumulative number of aphids to stop sampling was 131.

Bioactive Characterization of Bacillus thuriniensis subsp. kurstaki CAB133 Isolated from Domestic Soil (국내 토양으로 분리된 Bacillus thuriniensis subsp. kurstaki CAB133균주의 생물학적 특성)

  • Choi, Su-Yeon;Cho, Min-Su;Kim, Tae-Hwan;Kim, Jin-Su;Pack, Seung-Kyung;Youn, Young-Nam;Hong, Soon-Sung;Yu, Yong-Man
    • Korean journal of applied entomology
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    • v.47 no.2
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    • pp.175-184
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    • 2008
  • To screen highly active Bacillus thuringiensis isolates against Spodoptera litura (Lepidoptera, Noctuidae), 46 B. thuringiensis was isolated from 115 samples obtained from several crop soils. Especially, B. thuringiensis subsp. kurstaki CAB133 and CAB162 isolates showed 100% mortality against S. litura. $LD_{50}$ values of CAB 133, CAB162 and HD-1 strains of B. thuringiensis subsp. kurstaki were 0.089, 3.144 and $0.513{\mu}g/ml$ against 2nd larva of S. litura, respectively. The weight of 3rd larva of S. litura which were fed crystal inclusion protein $(1.267{\mu}g/ml)$ with B. thuringiensis subsp. kurstaki CAB133 was about 30 times lass than control group. CAB133 and CAB 162 strains of B. thuringiensis subsp. kurstaki which were taken a highly toxity against S. litura were analyzed by SDS-PAGE, and estimated the molecular weight of the Cry proteins. Their serological identification by H serotypes were showed B. thuringiensis subsp. kurstaki (3abc) type.

Studies on the Epidemiology and Control of Bacterial Leaf Blight of Rice in Korea (한국에 있어서의 벼흰빛잎마름병의 발생생태와 방제에 관한 연구)

  • Lee Kyung-hee
    • Korean journal of applied entomology
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    • v.14 no.3 s.24
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    • pp.111-131
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    • 1975
  • The study has been carried out to investigate the occurrence, damage, characteristics of the pathogen, environmental conditions affecting the disease outbreak, varietal resistance, forecasting, and chemical control of bacterial leaf blight of rice in Korea since 1964. Bacterial leaf blight of rice became a major disease in Korea since 1960. A correlation was found between the annual increase of epidemics and increase of cultivation area of susceptible varieties, Jinheung, Keumnampung etc. Areal damage within the country showed that the more was at southern province, Jeonnam, Gyeongnam and western coast, and at flooded rice paddy. Yield reduction directly related with the amount of infection on upper leaves at heading stage. Fifty per cent of reduction resulted when the lesion area was more than 60 per cent. Less than 20 per cent of lesion area, however, was not affected so much on yield loss One hundred and six isolates collected from all over the country were classified as 8 strains by using 4 different bacteriophages in 1973. It was, however, only two in 1965. There were some specificities on varietal distributions among the strains such as that the Jinheung attacked mainly by strain A, B, C and I, those attack Kimmaze were A, B, H and I. Most strains were found from Tongil except D and E, whereas Akibare was only variety that attacked by strain E. Low temperature, high humidity, heavy rainfall and insutficient daylight favored the disease epidemics. Especially, typhoon and flooding at heading stage were critical factors. The earlier transplanting the more disease was resulted, and more nitrogen fertilizer application accerelated the diseased development in general. The resistance to the disease varied by growing stage of the sane plants. All of recommended varieties in Korea were susceptible to the disease except Norm No. 6 and Sirogane which moderately resistant. The pathogen, Xanthomonas oryzae, was detectable from extract of healthy seedlings that were grown in the field with an heavy infection previous year. The more bacteriophage in irigation water resulted the more disease outbreak, and the existence of more than 50 bacteriophages in 1ml. of irrigation water were necessary to initiate the disease out break. The curves representing occurrence of bacteriophages and disease outbreak were similar with 15 days interval. The survey of bacteriophage occurrence can be utilized in forecasting of the disease two weeks ahead of disease outbreak. Three applications of chemicals, Phenazin and Sangkel, in weekly intervals at the early satage of out-break depressed the symptom development, and increased yield by 20per cent. Proper period for the chemical application was just before the number of bacteriophage reaches 50 in 1ml. of irrigation water.

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