• Korean journal of applied entomology
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• v.61 no.1
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• pp.155-163
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• 2022

The application of fungicides is indispensable to global food security, and their use has increased in recent times. Fungicides, directly or indirectly, have impacted insects, leading to genetic and molecular-level changes. Various detoxification mechanisms allow insects to eliminate reactive oxygen species (ROS) toxicity induced by agrochemicals including fungicides. In the present study, we analyzed the mRNA expression levels of detoxifying enzymes in Tenebrio molitor larvae following exposure to non-lethal doses (0.2, 2, and 20 ㎍/µL) of a fungicide captan. Transcripts of peroxidases (POXs), catalases (CATs), superoxide dismutases (SODs), and glutathione-s-transferases (GSTs) were screened from the T. molitor transcriptome database. RT-qPCR analysis showed that TmPOX5 mRNA increased significantly 24 h post-captan exposure. A similar increase was noticed for TmSOD4 mRNA 3 h post-captan exposure. Moreover, the expression of TmCAT2 mRNA increased significantly 24 h post-treatment with 2 ㎍/µL captan. TmGST1 and TmGST3 mRNA expression also increased noticeably after captan exposure. Taken together, these results suggest that TmPOX5 and TmSOD4 mRNA can be used as biomarkers or xenobiotics sensors for captan exposure in T. molitor, while other detoxifying enzymes showed differential expression.

• Journal of Korean Society of Rural Planning
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• v.1 no.2
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• pp.103-121
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• 1995

This study was carried out to identify the problems and policy alternatives for the improvement of living conditions and environmentally friendly agriculture. The results of surveys on the current situations of living conditions in the rural areas revealed that the main cause of depopulation in Korean rural villages was the lack of social infrastructure and income sources. The current government policies for agriculture geared mainly for improvement of international comparative competitiveness will result in the further disadvantage against the mountainous regions with marginal agricultural lands. Therefore, it is recommended that the agricultural policy should be complemented by the environmental and social policies in the less favoured areas. This can be justified by the fact that the demand for environmental public goods such as recreational opportunities in rural settings uncontaminated by the industrial wastes is growing.

• The Plant Pathology Journal
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• v.33 no.5
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• pp.499-507
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• 2017

In an attempt to develop a biological control agent against mycotoxigenic Fusarium species, we isolated Bacillus amyloliquefaciens strain DA12 from soil and explored its antimicrobial activities. DA12 was active against the growth of mycotoxigenic F. asiaticum, F. graminearum, F. proliferatum, and F. verticillioides both in vitro and in planta (maize). Further screening using dual culture extended the activity range of strain DA12 against other fungal pathogens including Botrytis cinerea, Colletotrichum coccodes, Endothia parasitica, Fusarium oxysporum, Raffaelea quercus-mongolicae, and Rhizoctonia solani. The butanol extract of the culture filtrate of B. amyloliquefaciens DA12 highly inhibited the germination of F. graminearum macroconidia with inhibition rate 83% at a concentration of $31.3{\mu}g/ml$ and 100% at a concentration of $250{\mu}g/ml$. The antifungal metabolite from the butanol extract was identified as iturin A by thin layer chromatography-bioautography. In addition, volatile organic compounds produced by DA12 were able to inhibit mycelial growth of various phytopathogenic fungi. The volatile compounds were identified as 2-heptanone, 5-methyl heptanone and 6-methyl heptanone by gas chromatography-mass spectrometry (GC-MS) analysis. These results indicate that the antagonistic activity of Bacillus amyloliquefaciens DA12 was attributable to iturin A and volatile heptanones, and the strain could be used as a biocontrol agent to reduce the development of Fusarium diseases and mycotoxin contamination of crops.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.08a
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• pp.1-12
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• 2005

• 한국균학회소식:학술대회논문집
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• 2009.05a
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• pp.15-17
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• 2009

• Research in Plant Disease
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• v.23 no.4
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• pp.295-305
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• 2017

This study aimed to investigate the plant growth-promoting and biocontrol potential of a grass culture with Paenibacillus ehimensis KWN8 on tomato. For this experiment, treatments of a chemical fertilizer (F), a bacterial grass culture (G), a 1/3 volume of G plus 2/3 F (GF), and F plus a synthetic fungicide (FSf) were applied to tomato leaves and roots. The result showed that the severity of Alternaria solani and Botrytis cinerea symptoms were significantly reduced after the application of the bacterial grass culture (G and GF) and FSf. In addition, root mortality in G and GF was lower compared to F. Tomato plants treated with G or GF had better vegetative growth and yield compared to F. Application of G affected the fungal and bacterial populations in the soil. In conclusion, treatment with a bacterial grass culture decreased disease severity and increased tomato growth parameters. However, there were no statistically significant correlations between disease occurrence and tomato yields. This experiment presents the possibility to manage diseases of tomato in an environmentally friendly manner and to also increase the yield of tomato by using a grass culture broth containing P. ehimensis KWN38.

• Korean Journal of Environmental Agriculture
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• v.37 no.2
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• pp.125-134
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• 2018

BACKGROUND: Green peach aphid (Myzus persicae) is an insect pest that significantly affects crop production. A number of pesticides have been used for aphid control, but their concerns on insect resistance and food safety have required alternative methods for pest management. In an effort to find for an alternative approach to aphid control, we screened plants extracts and examined their potentiality as insecticidal bio-resources. METHODS AND RESULTS: Two hundred and ninety eight plant extracts were examined for insecticidal activity against the aphid, and the best candidate among them was chosen for further study. The extracts from Cinnamomum camphora was determined to be the best candidate exhibiting insecticidal activity more than 60% at a level of $1,000{\mu}g/mL$. GC/MS analyses detected camphor, borneol, 4-terpineol, ${\alpha}$-terpineol and caryophyllene oxide as major compositions from the extracts obtained by hydrodistillation. Caryophyllene oxide exhibited the highest insecticidal activity with a $LC_{50}$ value of $237{\mu}g/mL$. Camphor lowered significantly the $LC_{50}$ value of caryophyllene oxide and increased largely its concentration in aphid, suggesting that camphor played a role in enhancing the insecticidal activity of caryophyllene oxide. CONCLUSION: This study suggested that camphor and caryophyllene oxide may be used as an insecticidal bio-resource for insect control against green peach aphid.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.415-422
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• 2006

This study aims for suggesting an idea to plan the expansion of consuming environmentally friendly chestnuts by statistically analyzing the types and intentions for consumer's purchase of environmentally friendly point of production and export side. For this, the survey was performed on 650 housewives living in Seoul, new metropolitan cities such as Ilsan, Bundang, where is the central place of main consumption. As a result, it is more effective to plan the expansion of consumption as the activity of consumption promotion for environmentally friendly chestnut focused on specific target such as 3~4 members of family and 30~40's age of young housewives having with the academic background of above university graduate, large income of average monthly payment with over 4.5 million won and consumers who have experience to purchase environmentally friendly forest products. In order to achieve this goal, it is require to secure the stabilized dealer for the environmentally friendly forest products as well as to establish the appropriate price reflected by the value and quality of environmentally friendly chestnut which the consumers recognize. It is estimated that this price can be decided on the basis of willingness to pay for the environmentally friendly chestnut from the index which comes from the integrated and concentrated consumers' expectation as this study surveyed.

• Korean Journal of Organic Agriculture
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• v.14 no.3
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• pp.267-285
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• 2006

This study diagnosed the managerial ability of farmers in the Gokseong area and the Gwangyang area, and analysis was conducted especially placing focus on the difference in managerial ability on whether environmental friendly agriculture has been implemented or not. According to the analysis results, the average score of all the farmers was 63.9 out of the full score of 100 which can be seen to be a medium to high standard. Also, in the diagnosis results according to whether environmental friendly agriculture has been implemented or not, the ability scores of farmers practicing environmental friendly agriculture were higher than those who were not, but large differences between the item scores for information ability and cooperative ability were shown. This is connoting a very important meaning in terms of the point that correspondence is being made to the conditions required to possess market response capabilities to the high information systemization society to unfold in the future. As a result, the important issue can be seen to be personnel cultivation in order to possess self response capabilities through the development of education programs that can improve this kind of managerial ability and revision of support systems.

• Research in Plant Disease
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• v.23 no.1
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• pp.19-34
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• 2017

Recent worldwide demand for organic and sustainable agriculture products is driving the development of formulations of biopesticides effective in the field. Biopesticides have the benefit of environmentally-friendly qualities. However, biocontrol approaches largely have been ineffective in controlling plant pests in field conditions. Previously, we developed a cost-effective biocontrol formulation containing chitin and chitinase-producing biocontrol bacteria with field efficacy. This formulated product has successfully suppressed various plant diseases in the field conditions. In this review, we focus on ecological aspects and the potential mechanisms underpinning the success of chitinase-producing bacteria. In addition, we discuss the possibility on-site cultivation of the formulated products to further strengthen the approach as being farmer friendly and successful.