• Korean journal of applied entomology
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• v.49 no.1
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• pp.43-47
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• 2010

This study was conducted to investigate optimal conditions for formation of synnemata from Beauveria bassiana. The strain of B. bassiana was isolated from a host of Oncotympana fuscata in Halla mountain of Jeju island. The yield of synnemata was the highest at application of brown rice (90%) and silkworm pupae (10%) media. On the other hand, the other media did not result in formation of synnemata. The highest formation of synnemata was achieved at conditions of moderate air inflow and $20^{\circ}C$. The optimal moisture and light intensity for formation of synnemata were 60% and 300 lux, respectively. In addition, inoculation of the liquid spawn resulted in higher yield than that of asexual spore.

• International Journal of Industrial Entomology and Biomaterials
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• v.31 no.2
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• pp.75-78
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• 2015

The white-spotted chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae), is an economically important insect in Korea. Traditionally, it has been regarded as a medicine for preventing liver-related diseases and suppressing liver cancer. Recently, this beetle was enlisted as a temporal food ingredient by Korean Ministry of Food and Drug Safety. Therefore, this beetle is focused as a one of the important insects that are commercially reared and sold in Korea. As the economic importance of this beetle is growing, the suitable rearing conditions are needed for more detailed investigation. In this study, we compared three temperature conditions and two food additives, rice chaff and soybean cake, for its effects on the body weight change of third instar larvae of P. brevitarsis. Temperature is a major environmental factor that has tremendous effects on rearing insects. In additions, rice chaff and soybean cake are byproducts of other agricultural activities. Therefore, it is easy to get, and the price is comparatively low. However, they still have meaningful amount of nutrients. With four different kinds of feed and three temperature conditions on the third instar larvae of beetles, the body weight change was tracked for 14 wk. We concluded that 27.5℃ is the optimal temperature to rear the third instar larvae among three temperatures (25, 27.5, and 30℃). Among four different feeds, conventional fermented oak saw dust with rice chaff and soybean cake was the best feed for larval weight gain during 14 wk. However, feed with soybean cake at 30 ℃ was the best condition for rearing P. brevitarsis larvae when temperatures and feeds were compared at the same time.

• Korean Journal of Medicinal Crop Science
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• v.3 no.3
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• pp.240-245
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• 1995

This study was conducted to find out environment conditions in order to increase of growth and yield of tuberlets in pinellia ternata (Thunb.) Breit. The optimal temperature conditions for the growth of tuberlets were good rather temperature fluctuations than constant one and the optimal photoperiod was a 6hr-photoperiod. The growth of tuberlets to the kinds and concentration of growth regulators was good for 0. lppm 2.4- D, 10ppm kinetin and 50ppm gibberellin treatment. In colchicine soaking treatment, the growth of tuberlets was bad, but bulblets formation was good for 0. 05% colchicine treatment for 48hr. -soaking. In colchicine dropping treatment, dry tuber yield was good for 0. 1% colchicine treatment with once dropping for one day.

• Journal of Agricultural Extension & Community Development
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• v.19 no.3
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• pp.699-727
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• 2012

Conditions of farm crop switching are affected by several important external factors such as agricultural products import opening, policy support, and climate change. Farming environment is always changing; barriers to imports are becoming lower and lower because of FTA and others, and climate change affects a boundary line of cultivation. Those situations give farmers motivation to change crops in order to cope with them. In addition, crop switching has been done in response to the local government measures about purchase of local agricultural products according to the local food and the expansion of organic agricultural products in school meal. Even though the favorable environment toward crop switching has been created, there are not many researches or outcomes regarding crop switching. Only few studies focus on the list of decision-making in crop switching, and locally suitable crop selection is not treated. In order to utilize crop switching as a farm management strategy, the proper frame should be studied and practical researches on application possibility also need. Therefore, study on crop switching is in a timely, proactive manner because farms catch the chance of expansion of school meal by changing crops. This paper applies HERO model used for venture foundation process to crop switching process. Success factors of HERO model are comprised of Habitate, Entrepreneurship, Resource, and Opportunity, and these phased application factors are applied to crop switching process. By doing so, each phase success factor of crop switching can be uncovered. Three farm organizations supplying organic agricultural products to schools are studied in Gyeonggi province. As a result, the stabilization stage cannot be achieved because of the habitate conditions and social conditions with low risk bearing of crop switching and current school meal systems are the main problems to block the diversification of risks. In order to succeed in crop switching, constructing the habitate in local districts or in systems of school meal is more effective than supporting each farm.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.192-192
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• 2017

Direct-seeding cultivation of rice is increasing in Asia instead of transplanting system, because of its lower cost and operational simplicity. Low-temperature germinability (LTG) and anaerobic germinability (AG) are important characters for breeding of varieties for wide-spread adoption of direct-seeding cultivation in rice. This study was performed to characterize LTG and AG of seven rice varieties and identify varieties with strong germinability on both low-temperature and anaerobic conditions. The mean germination rate and germination vigor of seven varieties were 51.7% and 6.0 under low-temperature condition, respectively. Among these varieties, Cheongcheongjinmi and Hwanggeumnodeul had the highest germination rate of 80%, indicating that Cheongcheongjinmi and Hwanggeumnodeul have a good LTG. In anaerobic conditions, the germination rate and coleoptile length for all varieties were 47.6% and 3.2 cm, respectively. Of them, the highest germination rate and coleoptile length were observed in Subo and Hopum, respectively, suggesting that these two varieties are tolerant to anaerobic during germination stage. Molecular characterization by SDS-PAGE revealed that the protein patterns differed at 50 kDa, 40 kDa, and 22 kDa between low-temperature and anaerobic conditions. Varieties identified as good LTG or AG in this study may be used for developing new direct-seeding rice cultivars through pyramiding these traits in the breeding program.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.400-406
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• 2013

This study was conducted to investigate the growth and flowering of African marigold (Tagetes erecta L.) and salvia (Salvia splendens F. Sello ex Ruem & Schult.) seedlings before and after storage under fluorescent lamps and green LED radiation conditions with different light intensities during storage. The both seedlings were kept under a storage room controlled at $8^{\circ}C$ air temperature and $40{\pm}10%$ relative humidity conditions. Light intensities were maintained at 15 and $30{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ during storage. In lighting treatments, dry weight of African marigold at 28 days after storage was not significantly different, and decreased approximately 29% compared to pre-storage under dark treatment. There was no significant difference in the leaf area of salvia seedlings stored under dark condition compared to before storage, but the leaf area under green light radiation with higher light intensity (treatment GH) was two times greater than before storage. The survival rate after transplanting of African marigold stored under dark condition was 10%, and days to flowering increased compared to those stored under fluorescent and green light with higher light intensity (treatment FLH, GH). Comparing to before storage, growth and flowering of the both seedlings after storage were significantly promoted by the light exposure during storage. The present experimental results show that the light intensity should be decided to maintain minimum growth during lighting storage and storage quality of the seedlings such as flowering promotion and extended blooming period after lighting treatment during storage period from the above results.

• Korean Journal of Ecology and Environment
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• v.53 no.1
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• pp.73-79
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• 2020

Metarhizium anisopliae is one of the entomopathogenic fungi infecting Protaetia brevitarsis seulensis. Environmental conditions strongly affect the virulence of entomopathogenic fungus. To test the susceptibility of P. brevitarsis seulensis larvae to M. anisopliae, we determined level mortality rates under different rearing conditions: temperatures (20℃, 25℃, 30℃), relative humidities (RH; RH 40%, 50%, 60%, 70%), and water content in sawdust (40%, 50%, 60%). The mortality rate of larvae treated with 5×10⁶ conidia mL^-1 M. anisopliae was not significantly affected by rearing temperature, but was affected by low RH (40%) and low water content in sawdust (40%), both of which resulted in high mortality rates. Mortality rated among M. anisopliae-treated 1^st, 2^nd, and 3^rd instar larvae were highest in 1^st instar larvae.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.2
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• pp.207-213
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• 2014

The structural proteins of classical swine fever virus (CSFV) consist of nucleocapsid protein C and envelope glycoprotein $E^{rns}$ (E0), E1 and E2. Among them, E2, the most immunogenic of the CSFV glycoproteins, induces a protective immune response in swine. In this study, to determine the optimal expression conditions of glycoprotein E2 using baculovirus system, we investigated the influence of insect cells and media to the expression of recombinant E2. Recombinant virus containing glycoprotein E2 coding gene was constructed with bApGOZA DNA. Expression of the glycoprotein E2 was analyzed by SDS-PAGE and Western blot analysis using anti-CSFV E2 monoclonal antibodies. Expression of glycoprotein E2 in Sf21 cells was first observed after 3 days and reached a maximum on the 5th day after infection. Furthermore, the highest levels of glycoprotein E2 expression were observed at multiplicity of infection (MOI) of 5. When three different insect cell lines (Sf21, High-Five and Se301) were tested, High-Five cells showed the highest production. In addition, four different serum-free and serum-supplemented media, respectively, were tested for the expression of glycoprotein E2 and the budded virus (BV) titers. As a result, serum-supplemented medium provided the best conditions for protein production and the BV yield.

• Magazine of the Korean Society of Agricultural Engineers
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• v.28 no.2
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• pp.42-52
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• 1986

This study involves the estimation of optimal ranges of parameters for a linear watershed model. A well-known TANK model was chosen and a linear combination of four tanks assumed. The model was used to simulate daily streamflow for six watersheds of different sizes and by a trial-and-error approach a set of optimal parameters defined. The parameters were related to watershed sizes and land use conditions. Optimal parameters for ungaged conditions were defined from the relationships; daily streamflow simulated and compared to the observed date. The simulated results were in a general agreement with the data.

• Journal of applied mathematics & informatics
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• v.18 no.1_2
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• pp.405-417
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• 2005

In this paper, the oscillation and asymptotic stability behavior of a third order linear impulsive equation are investigated. A lemma is presented to deal with the sign relation of the nonoscillatory solutions and their derived functions. By the lemma explicit sufficient conditions are obtained for all solutions either oscillating or asymptotically tending to zero. Two illustrative examples are proposed to demonstrate the effectiveness of the conditions.