• Microbiology and Biotechnology Letters
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• v.29 no.3
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• pp.186-193
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• 2001

A powerful antagonistic bacterium against Phytophthora capsici causing phytophthora blight of red pepper was isolated from the cultivated soil in Kyongju Korea, The bilogical control mechanisms of the isolated strain were caused by strong antifungal antibiotic, siderophore and cellulase. The strain was identified as Chryseomonas luteola by the cultural morphological and physiological characteristics. The opti- mal culture medium for the antibiotic production was determined as follows : 0.15%D(+) cellobiose, 0.55% $NH_4$CI, 0.01% KCI 0.7% $K_2$$HPO_4$ 0.2% $KH_2$PO$_4$ and 0.5% sodium citrate at pH 7.0 The optimal incubation time was 84 hours at $30^{\circ}C$ In pot bioassay, the treatment of C luteola 5042 protected red pepper plant against the blight of Phytophthora capsici.

• Current Research on Agriculture and Life Sciences
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• v.8
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• pp.65-70
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• 1990

Effects of nematode-parasitic fungus, Paecilomyces lilacinus, on root-knot nematode, Meloidogyne hapla, and growth and yield of consecutively grown lettuce and pepper were evaluated and compared to three soil fumigants, Telone II, TeloneC-17 and Dowfune MC-II, in greenhouse plots from 1983 to 1984 at Milyang, Korea. The number of nematodes in fungus plots, Telone II plots, Telone C-17 plots, and Dowfume MC-II plots at 25 days after treatment were 22, 2, 24 and 0, respectively, while untreated control plots were 685. At 350 days after treatment, 66%, 98%, 98% and 96% control of root-knot nematodes were observed in fungus plots, Telone II plots, Telone C-17 plots, and Dowfume MC-II plots, respectively. Lettuce yields were increased 49%, 43%, 31% and 109% and pepper yields were increased 33%, 49%, 37%, and 95% in fungus plots, Telone II plots, Telone C-17 plots, and Dowfume MC-II plots, respectively. Fresh weight and plant height of pepper were higher only in fumigant treated plots than untreated control plots.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.122-130
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• 2013

The object of this study is to review the current states of the characteristics and strategies to control annual bluegrass to apply information to the circumstance of South Korea. Annual bluegrass is one of the most widespread turfgrass species which has great ability to produce seedhead and shoot growth. It also has ability to tolerate low mowing height and to form uniformity of turfgrass when it is established. Annual bluegrass is well-known as weak turfgrass for high and low temperature. High rate of nitrogen and phosphorus improves growth of annual bluegrass. To control annual bluegrass, deep and infrequent irrigation is more effective than light and frequent irrigation. Clipping removal is more effective than clipping return to control annual bluegrass. Prodiamine, bensulide, and dithiopyr are applied as pre-emergence herbicide, and ethofumesate and bisbyribac-sodium are used as post-emergence herbicide. Paclobutrazol and flurprimidol are used as plant growth regulator. Trinexapac which is one of the most popular plant growth regulators (PGRs) in South Korea is not proper to control annual bluegrass because it accelerates improve growth of annual bluegrass in summer. Although chemical control is mainly used in South Korea, combination of cultural and chemical control may be the strategy to maximize effectiveness to control annual bluegrass.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.90-96
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• 2017

Gray mold disease, cause by Botrytis cinerea, occurs severe damage on varieties of fruit and vegetable production, and have no a critical control method. In case of chemicals control, it is a trigger emergence of drug resistance strains due to using them continuously. In addition, the pathogen is difficult to control naturally because it is possible to survive regardless of host status. In this study, microorganisms were isolated from tomato flower and hive samples and in order to select suitable microbial control agents for tomato gray mold disease. During six-months study, we isolated 1,004 isolates from flower and 925 isolates from pollinator hive samples. Among them, 6 strains were selected based on result of antifungal activity test. The selected strains showed not only strong antifungal activity against gray mold pathogen, but also cellulase and protease enzyme activities. The selected strains were identified as Paenibacillus polymyxa. In plant assay, P. polymyxa prevented the gray mold disease occurrence near 75%.

• Research in Plant Disease
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• v.17 no.1
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• pp.90-94
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• 2011

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a very serious disease in rice growing regions of the world. There are no effective ways of protecting rice from the disease. In this study, the bacteriophage (phage) mixtures infecting Xoo were investigated as biological control agent on BLB. The effects of pH, heat and ultraviolet on the stability of phages were investigated to check and increase the possibility of practical use in the field. Phages were rather stable between pH 5 and pH 10. The infectivity dropped sharply when the phages were incubated at $50^{\circ}C$ and more than 90% of the phages were inactivated after two minutes of ultraviolet treatment. The phages were stable for 7 days at the rice plant leaves, and the phages survived 10 times more than other treatments when mixed with skim milk. Although the skim milk increased the stability of the phages, the control efficacy was not effective. However, the phage mixtures reduced the occurrence of BLB when they were treated with Tecloftalam WP or Acibenzolar-S-methyl simultaneously. The results indicated that the Xoo phages could be used as an alternative control method to increase the control efficacy and reduce the use of agrochemicals.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.49-49
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• 2019

국립수목원은 열대유용식물의 BT산업 원천소재 확보 제공을 목적으로 열대자원연구센터를 건립하여, 열대 및 아열대 전시원을 관리하고 있다. 온실의 특성상 일반 재배환경과는 다르게 여러 종류의 식물의 혼합 식재되어 있는 특성이 있어서 농업환경과 달리 해충의 급격한 돌발에 의한 온실 전체적인 피해의 위험성이 적은 반면에 안정된 환경으로 인해서 해충의 취약한 몇몇 수목의 경우 해충이 급격히 늘어날 수 있다. 본 실험은 여러 종류의 식물이 혼재되어 있는 수목 온실 내에서 생물적 방제를 이용하여 주요 해충류인 진딧물류 및 가루 깍지벌레, 잎응애류 방제 가능성을 타진하고자 진행되었다. 진딧물이 집중적으로 발견된 열대식물 5종(Acalypha hispida, Justicia gendarussa, Hamelia patens, Ficus petersii, Hibiscus rosa-sinensis)을 중심으로 천적 방사 및 Banker plant 설치를 진행했다. 최초 조사일인 2015년 3월 10일, Tropical 1에 진딧물류의 발생이 많이 확인되어 포식성 천적인 미끌애꽃노린재를 투입했다. Tropical 2는 2015년 3월 17일 기생성 천적인 콜레마니진디벌과 선발된 Banker plant를 적용하여 방제 되었다. 철모깍지벌레가 발견된 열대식물 3종(Sanchezia parvibracteata, Brillantaisia lamium, Pseuderanthemum atropurpureum)을 중심으로 적용 천적으로 어리줄풀잠자리, 애홍점박이 무당벌레와 깍지무당벌레를 선별했다. 천적을 대상으로 철모깍지벌레에 대한 포식능력을 조사했으며 애홍점박이 무당벌레가 어리줄풀잠자리 보다 2.8배, 깍지무당벌레보다 2.9배 포식능력이 뛰어남을 확인했다. 잎응애류가 발견된 열대식물 2종(Acalypha wilkesiana, Erythrina caffra)은 천적으로 사막이리응애와 칠레이리응애를 적용하였다. 괭이밥응애 성충과 알의 포식력을 검증한 결과 사막이리응애가 괭이밥응애를 먹이로 증식이 가능한 것으로 확인되었다. 괭이밥, 괭이밥응애, 사막이리응애를 효과적으로 조합한 응애류 방제를 위한 새로운 Banker plant의 개발 가능성을 확인할 수 있었다. 연구는 열대온실의 열대식물 관리에 대한 생물학적 방제의 지속적인 모니터링을 통해 종합적 방제의 관리 자료로 이용되어 새로이 온실을 조성하는 경우 식재기반조성에 실질적인 도움을 줄 수 있으며, 추후 열대식물의 자원 식물로서의 활용성을 높일 수 있다.

• Microbiology and Biotechnology Letters
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• v.25 no.4
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• pp.396-402
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• 1997

Biocontrol of plant pathogens provides an alternative means of reducing the incidence of plant diseases without the negative aspects of chemical pesticides. Nowdays, as the resistant fungi about the chemical fungicides have revealed and the concern of environment has increased, the biological control of phytopathogenic fungi by the antagonistic microorganisms is very much indispensable. For the selection of strong antagonistic bacterium for biological control agent of rice leafblast and cucumber gray mold rot, the antifungal strain KL-3 strain was selected among 120 strains isolated from the rhizosphere soils. And the strain was identified to be a species of Bacillus subtilis or closely related strain. In several biochemical and in vitro antibiosis tests, antifungal substances of Bacillus sp. KL-3 were presumed heat stable, micromolecular antibiotic substances. In vivo test and vinyl house field test, the antifungal substances of Bacillus sp. KL-3 represented excellent biocontrol ability aganist Alternaria mali, Phyricularia oryzae, and Alternaria kikuchiana as well as broad spectrum of other fungi. In particular, Bacillus sp. KL-3 strain showed more predominant activity than some chemical fungicides against fungi shown to resist chemcal fungicides.

• The Korean Journal of Mycology
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• v.30 no.1
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• pp.50-55
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• 2002

Biological control against mushroom fly, Lycoriella mali, was performed by using Bacillus thuringiensis subsp. israelensis Bti-D and Bti-U, isolated from dead mushroom fly in oyster mushroom houses. Control values of the bacterial strains Bti-D and Bti-U against L. mali in bottle culture of oyster mushroom were 74.4% and 64.2%, respectively, and the value in small tray culture were 75.8% and 56.8%, respectively. In the experiment to develop the mass, cheap media for Bti-D and Bti-U isolates, the Biji broth (bean curd residue, called Biji in Korean language) was selected as a culture medium for an inexpensive and mass cultivation by the measurement of optical density of the two bacteria grown in the different media tested. Insecticidal effect of the formulation contained different ingredients that were prepared by using the Bti-D strain cultured in the Biji broth was tested in tray and bottle culture of oyster mushroom. The WCS formulation that contained corn starch as bio-gel (86.4%) was more effective to control the mushroom fly than living cells (69.1%) in bottle culture of oyster mushroom. Moreover, insecticidal effect of the WCS formulation was improved when water of pH 8 was used for dilution of the formulation. Effect of the WCS formulation using water of pH 8 and chemicals, Zuron (dimillin) W.P. on the control of mushroom fly and the productivity of oyster mushroom was investigated in tray culture of oyster mushroom. The Zuron W.P. was more effective to control the mushroom fly than the WCS formulation. However, compared with no treatment, the productivity of the mushroom treated with the WCS formulation was improved than that of the mushroom with Zuron W.P.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.23-28
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• 2007

Auxin-producing antagonistic bacterium K11, which can inhibit Phytophtora capsici, was isolated from a local red-pepper field soil in Gyeong-buk. In order to check for additional PGPR(plant growth promoting rhizobacterium) functions of the strain K11, we confirmed siderophore and cellulase productions by CAS (chrome azurol S) blue agar and CMC plate with congo red, respectively. The strain K11 was identified as Bacillus licheniformis with 98% similarity on 16s rDNA comparison and Biolog analyses. B. licheniformis K11 promoted mung bean adventitious root induction and enhanced root growth of mung bean (160%), pea (150%), and Chinese cabbage (130%), Also, B. licheniformis K11 was able to effectively suppress (63%) P. capsici causing red-pepper blight in the pot in vivo test. Therefore, we could select a triple-functional PGPR which has auxin, siderophore, and cellulase producing ability for effective crops production in organic farming.

• Korean Journal of Microbiology
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• v.33 no.3
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• pp.193-198
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• 1997

Microorganisms capable of producing biosurfactant were isolated from oil-contaminated soils and seawater. Among them, the selected strain SW1 was identified as Pseudomonas sp. by taxonomical characteristic tests, and so tentatively named Pseudomonas sp. SWI. The optimal temperature and initial pH for biosurfactant production were TEX>30^{\circ}C.$ and 7.0, respectively. The optimal medium composilion for the production of biosurfactant by Pseudomonas sp. SW1 were hexadecane of 2.0%, yeast extract of 0.04%, $K_{2}HPO_4$ of 0.02%, $KH_2PO_4$ of 0.03% and $MgSO_4$ center dot $7H_2O$ of 0.04%, respectively. Under the above conditions, minimum wrface tension was 32 mN/m after incubation of 2 days. The biosurfactant was produced during initial stationary phase in the optimal medium. Pseudotnonas sp. SWl utilized various hydrocarbons such as Bunker oils, n-alkanes and branched alkanes as a sole carbon source.