• Korean journal of applied entomology
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• v.58 no.4
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• pp.271-280
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• 2019

We investigated the control efficacy and phytotoxicity of unmanned aerial vehicle-applied pesticides against the insect Spodoptera exigua, a major emerging pest in Chinese cabbage. Phytotoxicity was investigated in cabbage and 7 crops cultivated in the perconducted on 8 surrounding crops including Chinese cabbage at 1 to 2 times the recommended pesticide dosage. We treated cabbage fields with spinetoram suspension concentrate (16×), methoxyfenozide, sulfoxaflor suspension concentrate (16×). Then, we used water-sensitive paper to measure the distribution pattern of falling pesticide particles and the degree of coverage. Two of the pesticides showed 97% control efficacy, however, control efficacy might differ in resistant populations. Phytotoxicity was not observed in Chinese cabbage and the 7 surrounding crops treated with 1 to 2 times the recommended pesticide dosage. Analysis of the distribution pattern of falling pesticide particles revealed that breeze caused particle diffusion. Thus, wind is an important factor affecting the uniform treatment and diffusion of multicopter-applied pesticides. It follows that setting optimal conditions is necessary for effective control and treatment.

• Korean journal of applied entomology
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• v.59 no.2
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• pp.83-91
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• 2020

We assessed efficacy of spraying pesticides from an unmanned helicopter to control two insect species, Monochamus alternatus and M. saltuarius, which are vectors of pine wood nematodes. Control efficacy of thiacloprid FL (33×), acetamiprid ME (33×), and flupyradifurone SL (33×) was determined by placing caged insects in the canopy of pine trees (Pinus sp). Water-sensitive paper was used to record the spray pattern of pesticide droplets and the degree of coverage; furthermore, we investigated peripheral scattering due to spraying. The three pesticides showed > 96% control efficacy against the targeted vectors, and pesticide droplet spray patterns were similar. Peripheral scattering was observed up to 20 m in front and 10 m to the left, right, and behind the targeted area. The coverage index of all the directions at 5 and 10 m distance was 6-7 and 2, respectively.

• The Korean Journal of Pesticide Science
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• v.17 no.3
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• pp.231-236
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• 2013

A solution on pesticide minor use is being requested world widely on behalf of growers and for the appropriate measure for pesticide regulation. Presently, definition on "minor use" is different by country. And furthermore registration for pesticide use and the regulation approach are dependent on whether the crop is minor or major. For these reasons, management for pesticide minor use are more complicated and aggravated. This paper aimed to provide information on definition of minor use, minor use programs and regulatory incentives for minor use registration, with the purpose of supporting in developing a possible solution on minor use situation in Korea. In conclusion, two suggestions were made based on the worldwide information on pesticide minor use. First, a prudent consideration should be taken in defining minor use legally in Korea, which should include all situations regarded with minor use of pesticide, besides the use of pesticide on the crops cultivated in small area. Secondly, it is proposed to strengthen the present program, the "Ex Officio Registration" (implemented since 1998 in Korea, lead by the Rural Development Administration) by introducing a cooperative program like IR-4 Project of the USA, which is well known as an effective program for minor use solution as mentioned in the OECD guidance.

• Agrochemical news magazine
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• v.22 no.6 s.169
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• pp.22-23
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• 2001

만일 미국인 소비자들에게 식품과 농산물에 생명공학을 적용하는 것을 지지하느냐고 물으면 그들 중 약 $70\%$는 ''그렇다''고 답할 것이다. 하지만 질문의 각도를 좀 달리해서 ''당신은 유전자변형식품(GMO)을 먹어도 된다고 생각하는가''라고 묻는다면 3분의 2가량은 ''아니다''고 대답할 것이다. 하지만 이 두가지 질문은 사실상 같은 것이다. 다만 두번째 질문속의 ''유전자''와 ''변형'' 같은 말들이 수백만명의 소비자들의 경계심리를 자극하는 것이다. GMO 기술은 적절하게만 사용된다면 식품의 영양을 개선하고 농업생산량을 증대시켜 농가소득을 높이고 심지어 환경적 위해 요소를 줄일 수 있다. 하지만 이 기술이 현재 부적절하게 시험되고 잘못 적용되는 등 불완전하게 규제될 경우 영양학적으로나 환경적으로 큰 위해로 작용할 수 있다. 따라서 이에 대한 정확한 이해와 득실을 알아 둘 필요가 있다.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.538-543
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• 2018

Powdery mildew caused by Podosphaera xanthii is a disease in cucurbit crops especially in green house. The objective of this study was to determine the effect of alternative fungicide spraying system for control of powdery mildew disease. We selected four fungicides with different mode of action and made three treatment combinations of each fungicide in 2017. Pyraclostrobin-flutianyl-penthiopyrad treatment showed the highest control value (87%) while, pyraclostrobin-pyraclostrobin-pyraclostrobin treatment showed the lowest control value (32.5%). So it seemed like the treatment was not suitable for control of powdery mildew. In 2018, pyraclostrobin of pyraclostrobin-flutianyl-penthiopyrad was replaced to contact fungicide called iminoctadine-tris-albesilate and compared control effect of two treatments. Two of the treatments showed similar control value (87.0% for pyraclostrobin, 89.0% for iminoctadine-tris-albesilate). These two tests in 2017 and 2018 indicated that alternative treatment of different fungicides is essential for controlling of powdery mildew and inhibiting development of fungicide resistance.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.159-164
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• 2016

The winter cherry bug (Acanthocoris sordidus Thunberg, Coreidae, Hemiptera) is a insect pest that have a piercing sucking type mouthpart, and it is injured to solanaceous plants including pepper plant. For the control of the winter cherry bug, 20 organic synthetic insecticides and 7 environmental friendly agricultural materials (EFAMs) were selected with single formulation. Fenitrothion, fenthion and phenthoate were significantly higher mortality to adults and 3rd instar nymphs of winter cherry bug as over 95 and 100 % after 72 hours with treatment. Otherwise, in case of EFAMs, there is no significantly higher effective materials to adults and 3rd instar nymphs of winter cherry bug. Eighty percentage of Sophora flavescens was showed only around 50% mortality with the high variation after 72 hours with treatment against adult of the winter cherry bug.

• Research in Plant Disease
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• v.12 no.1
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• pp.32-39
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• 2006

This study has been conducted to investigate the responses of various isolates of four Colletotrichum species such as C. gloeosporioides, C acutatum, C. coccodes, and C. dematium isolated from infected tissues of several crops to fungicides such as carbendazim, carbendazim+diethofencarb, four protective fungicides, and three ergosterol biosynthesis-inhibiting (EBI) fungicides. All the isolates of C. acutatum showed $EC_{50}$ values in a range of 0.001-3.040 ${\mu}g/ml$ against carbandazim, a benzimidazole fungicide. As for the response to carbendazim, the isolates of C. gloeosporioides obtained from pepper, apple, and strawberry were clearly divided into two groups, resistant or sensitive isolates. All the resistant isolates showed $EC_{50}$ values above 1000 ${\mu}g/ml$, whereas the sensitive isolates had lower $EC_{50}$ values than 0.550 ${\mu}g/ml$. The isolates of C. gloeosporioides exhibited a negative cross resistance between carbendazim and diethofencarb (a N-phenylcarbamate fungicide), but isolates of C. acutatum did not. Toward carbendazim, C. coccodes and C. dematium isolates showed a similar response to C. acutatum isolates and the sensitive isolates of C. gioeosporioides, respectively. As for response of Protective fungicides, all the isolates of C. acutatum showed a more resistant reaction than all the isolates of C. gloeosporioides. However, there was no difference among 4 species of Colletotrichum against EBI fungicides.

• Korean Journal of Organic Agriculture
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• v.10 no.2
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• pp.95-109
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• 2002

This study focussed to find out the agronomic effect of high quality compost mixed with brown seaweed and to determine the optimum mixing rate of seaweed to compost for environmentally benign organic farming. The experiment was conducted in lysimeters at Experimental Farm of Dankook University with Chinese Cabbage(Bulam #1), and the crop growth such length and width of leaf, biomass of Chinese Cabbage were checked, the content of chlorophyll, sugar, vitamin C, nitrate in outer leaf and idler leaf was determined. It was observed that nitrate content was dramatically decreased in the plot of mixture with seaweed, while biomass and content of Vitamin C were increased steeply in the plot of mixture with seaweed. The best result was gained the 0.25% mixture of brown seaweed with compost.

• Korean journal of applied entomology
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• v.60 no.3
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• pp.287-304
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• 2021

Since 1995, researches on natural enemies have been conducted extensively in Korea. Research papers on natural enemies published in the Korean Journal of Applied Entomology from 1990 to 2020 were 130, which is 8.4% of all published papers during the same period. In 1990s, most research papers study the searching and biological characteristics of natural enemies, whereas the proportion of research papers related to the field application using the developed natural enemies has been increasing since 2010s. A total of 37 excellent natural enemies have been developed including 24 indigenous and 13 introduced natural enemies. In addition, 28 kinds of booklets and/or manuals were developed for field application of natural enemies. Although successes in research and development have been achieved since that period, more researches on search for and/or introduction of excellent natural enemy suitable for the Korean cultivation environment, mass production technology that can reduce cost, and quality control program in producing and distributing natural enemy remain to be pursued in the future. Furthermore, there is a need to develop the technology that can be used in compatible way with natural enemies and other crop protection agents including synthetic insecticides.

• The Korean Journal of Pesticide Science
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• v.13 no.3
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• pp.185-189
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• 2009

A monoterpenoid compound, benzylideneacetone (BZA), is a metabolite of an entomopathogenic bacterium, Xenorhabdus nematophila. Its primary biological activity is an inhibitor of phospholipase $A_2$, which catalyzes the committed step of biosynthesis of various eicosanoids that are critically important to mediate insect immune responses. When BZA was applied to two-spotted spider mite, Tetranychus urticae, it exhibited a dose-dependent mortality in leaf-disc assay. Subsequently BZA was tested against T. urticae infesting apples in a field orchard, in which it showed a significant control efficacy, which was not statistically different with that of a commercial acaricide. BZA also had significant antibacterial activities against three species of plant pathogenic bacteria when it was added to the bacterial cultures, in which it showed the highest inhibitory activity against a bacterial wilt-causing pathogen, Ralstonia solanacearum. The bacterial pathogen caused significant disease symptom to young potato plants. However, BZA significantly suppressed the disease occurrence. This study suggests that BZA can be used to develop a novel crop protectant to control mite and bacterial pathogen.