• Korean Journal of Poultry Science
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• v.47 no.4
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• pp.211-217
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• 2020

This study evaluated calcium hydroxide (slaked lime) and a combination of plant extracts ('natural product'; clove, cinnamon, and saponin; 1:1:1 ratio) as acaricidal control mechanisms for poultry red mites. Red mite susceptibility was evaluated after treatments with 10% slaked lime, 20% slaked lime, and 1% natural product. The duration of the acaricidal effect was also tested at 0, 10, 30, and 60 min after treatment using 20% slaked lime, 1% natural product, or a mixture of both. In the in vitro experiment, the slaked lime treatments were 73.2% (10% slaked lime) and 85.1% (20% slaked lime) effective on red mites. In acaricidal effect of control materials over times, with 20% slaked lime, the acaricidal effect decreased to 50.7% after 30 min, and 12.7% after 60 min (P<0.05). With 1% natural product, there was no acaricidal effect after 30 min (P<0.05). With 20% slaked lime +1% natural product, all of poultry red mites died until 30 min, and 92.9% after 60 min (P<0.05). On the farm, poultry red mites were observed that the number of poultry red mites increased 7,923 from 36 to 45 weeks, but then decreased to 483 after 20% slaked lime plus 1% natural product treatment. These results indicate that combining slaked lime and plant extracts effectively control poultry red mites.

• Korean Journal of Organic Agriculture
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• v.21 no.3
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• pp.363-372
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• 2013

This experiment was carried out for development of environment-friendly agriculture materials to control Bemisia tabaci (Gennadius) in eggplant. Plant growth investigated the spray at intervals of 7 days after transplanting on 8 environment-friendly agriculture materials, such as egg-yolk and cooking oil, Results were to be good in the control and neem products. B. tabaci population density adult and nymph was low at the dinotefuran WG chemical treatment, and also low neem products of environment-friendly agriculture material. We have investigated the effect of different concentration of neem products on B. tabaci population density. Yield was high in the dinotefuran WG, and hight in the neem products and papper seed oil, but low in the sophora extracts and Ginko net sarcocarp. In the case of neem products treatment indicated 52 percent yield more than control.

• Korean Journal of Organic Agriculture
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• v.19 no.3
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• pp.405-416
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• 2011

Organic materials, such as chitin incubated solution (CIS) combined with neem oil (NO), nano silver silica (NSS), and Bordeaux mixture (BDM), were applied with and without agricultural chemicals (AC) (insecticide and fungicide) to investigate scab and mealybug occurrences and fruit qualities on 'Niitaka' pear trees in orchards in 2006. Fruits and leaves grown under CIS+NO without AC had less than 30%, scab occurrence, but CIS+NSS or CIS+BDM without AC had higher scab occurrence. Organic materials with AC decreased the scab to less than 20%. All treatments decreased mealybug occurrences to less than 10%, except for the fruits grown under CIS+BDM without AC. Fruit qualities varied among the treatments. Hunter value a, representing for the redness degree, was higher for fruits treated with CIS+NSS and CIS+BDM without AC than those with AC. Fruits treated with organic materials without AC had greater total phenolic and flavonoid compounds as well as antioxidant capacity in flesh and greater total phenolc compounds and antioxidant capacity in peel than those treated with the AC.

• Korean journal of applied entomology
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• v.51 no.2
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• pp.141-148
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• 2012

An outbreak of Ricania sp. occurred in the Kurye, Jeonnam area in 2011. This outbreak damaged many kinds of fruit trees such as Cornus, Persimmon and Chestnut. This experiment was conducted to survey the occurrence ecology of Ricania sp. such as host plants, oviposition characters, morphological characters and life cycle, as well as to select environmental friendly control agents. Ricaina sp. host plants included 51 species such as 32 xylophytes, and 19 herbaceous plants. Ricaina sp. preferred Cornus officinalis, Diospyros kaki, Castanea crenata, Eucommia ulmoides, Styrax japonicus for oviposition. Adults laid eggs on new inner twigs with 28.8 eggs per egg-mass. Egg size was 1.24 mm(length), 0.55 mm(width) in an oval shape. Nymphs molted four times. Every nymph stage had an x shape of yellow or white beeswax around the anus. Overwintered eggs of Ricania sp. hatched from the mid May to early June. Nymphal periods were from mid May to mid August and adults appeared from mid July but spawning began in mid August. Ricania sp. damaged new twigs by oviposition and retarded growth by sucking nutrients and producing a sooty mold. Sophora and natural plant extracts were effective environmentally friendly agricultural materials used to control the nymph and adult Ricania sp. Mortality was > 80%.

• Korean Journal of Agricultural Science
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• v.31 no.1
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• pp.45-52
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• 2004

Bakanae Disease is an abnormal plant growth caused by Gibberella fujikuroi. The infected plants several inches taller than normal plants in seedbed and field. To control bakanae disease, we made a seed disinfectant from garlic extract. And we isolated allicin($C_6H_{10}OS_2$) from garlic extract and the content was 0.62%. In order to develop efftive seed disinfectant from Garlic extract, we compared it with three seed disinfectants(benomyl, prochloraz, fludioxonil). Prochloraz, fludioxonil and Garlic wettable powder controlled Bakanae disease of rice very well, while benomyl did not suppress the disease enough. Water temperature was turned to be an important factor for controlling the disease by treating seed disinfectants. It was confirmed that the seed disinfectant from garlic extract can be used as non-toxic agricultural medicines.

• The Korean Journal of Pesticide Science
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• v.11 no.1
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• pp.38-45
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• 2007

Laboratory and greenhouse experiments were conducted to determine the herbicidal effect of two types of ${\delta}$-aminolevulinic acid (ALA), microbiologically-produced ALA (Bio-ALA) and synthetically produced ALA (Synthetic-ALA), on plant growth and chlorophyll content of Chinese cabbage. ALA effect on early plant growth was greatly concentration dependant, showing significant inhibition at higher concentrations. Both pre- and post-emergence application of ALA exhibited significant degree of photodynamic phytotoxicity. Older plants with many leaves were more tolerant to ALA than younger plants, showing less injury. No significant difference in herbicidal activity of two types of ALA, Bio-ALA and Synthetic-ALA, on plant height and chlorophyll content of Chinese cabbage was observed. However, residual biological activity and physico-chemical properties of Synthetic-ALA were more stable than those of Bio-ALA. Our results suggest that ALA had herbicidal potential with both pre- and post-emergence application, and that the chemical may be a valuable mean of eco-friendly weed control based on natural microbial substance.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.37-37
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• 2019

벼 재배포장에서 화학약제의 반복적인 사용으로 인한 병원균의 약제내성과 환경오염은 커다란 문제가 되고 있다. 이러한 약제내성을 극복하기 위한 노력의 하나로 유전자수준의 약제내성기작의 규명과 대체물질의 발굴이 필요하다고 사료된다. 이에 본 연구에서는 식물종이 지니는 광범위한 다양성에 주목하였고, 700여 종의 식물추출물을 벼 도열병균에 처리해 균사성장억제효과를 조사하는 선별실험을 실시하였고, 영릉향과 지모추출물이 높은 균사성장억제효과를 보이는 것을 확인했다. 영릉향과 지모 추출물이 화학약제를 대체하는 대안물질로서 가능성을 조사하기위해 균사성장억제능력 확인실험, 분획, HPLC (High Performance Liquid Chromatography), 포자발아 및 부착기 형성확인검정, ABC transporter의 발현조사, 환경독성실험등을 실시했다. 실험 결과, 영릉향과 지모 추출물을 벼 도열병균에 처리하였을 때 약제저항성유전자 ABC transporter의 기능이 저하되고 화학약제에 대한 내성이 감소를 확인했으며, 분획과 HPLC분석을 통해 영릉향과 지모의 유효성분을 확인했다. 또한, 실제 포장에서 영릉향 추출물과 지모 추출물을 사용하여 벼 도열병 방제가를 확인하는 포장시험을 실시한 결과, 각각 63%와 62%의 목 도열병 방제가를 확인 하였으며, 인축환경에 대한 유해성을 조사하기 위해 어류, 설치류, 중치류, 곤충을 대상으로 영릉향 추출물을 처리해 급성독성시험 실시한 결과, 고농도의 투여량에서도 독성이 없는 것을 확인했다. 위의 실험 결과를 토대로, 영릉향과 지모추출물이 화학농약에 의한 환경오염을 막을 수 있고, 인축과 환경에 피해를 입히지 않는 친환경자재로 친환경적인 생물농약의 신소재로서 가능성을 나타냈다고 사료된다.

• Korean Journal of Organic Agriculture
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• v.13 no.3
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• pp.291-300
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• 2005

Diseases were surveyed in 5 Rice paddy field areas of Organic paddy field and conventional paddy field. The 3 major diseases, rice leaf blast, bacterial leaf blight and sheath blight in rice were surveyed at duck raising, rice bran and conventional rice paddy field. They were serious in duck raising paddy field, rice bran paddy field more than conventional paddy field. The Ilpum variety were infected seriously more than Chucheong. At the effectivity test of the environment-friendly substance for the rice-seed sterilization, 1000-times diluted brown-rice vinegar showed controlling effect against Bakanae disease, and germination rate also was good. There was no Weeds Control efficacy by cultivating of hairy vetch in rice paddy field. However, extract of hairy vetch Leaf and root repressed the germinating of lettuce seed.

• Research in Plant Disease
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• v.23 no.3
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• pp.268-277
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• 2017

Fusarium head bight (FHB) is a devastating disease on major cereal crops worldwide which causes primarily by Fusarium graminearum. Synthetic fungicides are generally used in conventional agriculture to control FHB. Their prolonged usage has led to environmental issues and human health problems. This has prompted interest in developing environmentally friendly biofungicides, including botanical fungicides. In this study, a total 100 plant extracts were tested for antifungal activity against F. graminearum. The crude extract of Pterocarpus santalinus heartwood showed the strongest antifungal activity and contained two antifungal metabolites which were identified as ${\alpha}$-cedrol and widdrol by GC-MS analysis. ${\alpha}$-Cedrol and widdrol isolated from P. santalinus heartwood extract had 31.25 mg/l and 125 mg/l of minimal inhibitory concentration against the spore germination of F. graminearum, and also showed broad spectrum antifungal activities against various plant pathogens. In addition, the wettable powder type formulation of heartwood extract of P. santalinus decreased FHB incidence in dose-dependent manner and suppressed the development of FHB with control values of 87.2% at 250-fold dilution, similar to that of chemical fungicide (92.6% at 2,000-fold dilution). This study suggests that the heartwood extract of P. santalinus could be used as an effective biofungicide for the control of FHB.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.228-231
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• 2009

We have purified Phytophthora capsici alpha and beta tubulin from Escherchia coli BL21(DE3). The recombinant alpha and beta tubulins were assembled into microtubule in vitro with specific conditions. The metagenome library was isolated from soil in the Mt. Yeo-Ki, Suwon, Korea and manufactured with the method mentioned in experiment contents for in vitro screening of microtubule assembly screening. FRET effect was used for microtubule assembly inhibitor screening with metagenome library. We got 2 metagenome clones from in vitro screening, and these 2 hit clones showed P. capsici growth inhibition activity on the growing pepper plants. These results suggest that new development of potent inhibitor for pepper blight disease and new approach to prevention of pepper blight disease.