• 농업과학연구
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• 제44권3호
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• pp.339-347
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• 2017

Sclerotium rolfsii causing southern blight on numerous vegetable and fruit crops was isolated from stems of chili peppers showing wilting symptoms. The pathogen was identified by morphological observation and DNA sequencing analysis of ITS region. To select an effective fungicide for control of southern blight, we investigated the inhibition efficacy of thirty fungicides included in nine groups of fungicides with different mechanisms of action. A fungal growth inhibition assay was conducted through an agar dilution method by using mycelial discs and sclerotia of the pathogen as inoculum, respectively. When mycelial discs were used as an inoculum, several fungicides showed good inhibitory activity against the mycelial growth of S. rolfsii 12-6. All DMI fungicides tested had a good inhibition except for prochloraz which had low inhibitory effect. All strobilurin fungicides tested except for kresoxim-methyl and all SDHI fungicides tested except for boscalid and fluopyram, had a good inhibition. Also, fludioxonil, a protective fungicide and fluazinam had a good inhibitory effect. Interestingly, when sclerotia were used as an inoculum, inhibition efficacy was increased for fluopyram, a SDHI fungicide, and for some protective fungicides such as propineb, chlorothalonil, dithianon, and folpet. All the fungicides selected in this study should be tested in the field for their control activities against stem rot for practical use in chili pepper cultivation.

• The Plant Pathology Journal
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• 제28권1호
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• pp.101-106
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• 2012

Trifloxystrobin is a strobilurin fungicide, which possesses broad spectrum control against fungal plant diseases. We demonstrated that pre-treating red pepper plants with trifloxystrobin resulted in increased plant growth and leaf chlorophyll content compared with those in control plants. Relative water content of the leaves and the survival rate of intact plants indicated that plants acquired systemic tolerance to drought stress following trifloxystrobin pre-treatment. The recovery rate by rehydration in the drought treated plant was better in those pre-treated with trifloxystrobin than that in water treated plants. Induced drought tolerance activity by trifloxystrobin was sustained for 25 days after initial application. The trifloxystrobin treated red pepper plants also had induced systemic tolerance to other abiotic stresses, such as frost, cold, and high temperature stresses. These findings suggest that applying the chemical fungicide trifloxystrobin induced systemic tolerance to certain abiotic stresses in red pepper plants.

• 아시안잔디학회지
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• 제12권1호
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• pp.23-30
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• 1998

174 isolates of soil microorganisms were isolated from E-golf club from Apr.1997 through Oct. 1997. And 27 strains of them were selected through the inhihition test of mycelial growth. In the same period, soil-borne diesease pathogens, "Rhizoctonia", causing Large patch, Brown patch, Spring dead spot, and Yellow patch were isolated from the diseased areas in E-golf and S-golf club. The antagonistic activity of the strains against the pathogens was tested to select the excel-lent antagonists. In contact with the fungicides, the survivability of the antagonists was tested to assess the compatibility of the antagonists with the pesticides. The results were as follows: 1.Suppression of Rhizoctonia by Antagonists. Antagonistic activity of 27 strains against the pathogens was: tested in vitro. In the result, 3 isolates(B-7, B-15, B-41) of bacteria and 2 isolates(F-5, F-47) of fungi were superior to the rest. 2.Compatibility of the antagonists: with the fungicides: With 13 kinds of pesticides widely using Golf Club, Compatibility of 5 antagonists: were finally tested to select the strains: that mostly survived in contact with pesticides. In the results:, two of five strains: were selected : one strain was bacteria B-15, the other strain was fungi F-47. 24h after the mixing with pesticides:, these two strains were shown to survive at 90% level and these were identified as Bacillus and Trichoderma, respectively. And the most compatible pesticides: with the antagonists were shown to Polytoxin-D thirarn(s:urvivability 99.4%) and Validamycin-A (survivability 98.6%). Keywords:Antagonist, Large Patch, Trichoderma, Compatibility, Fungicide.Fungicide.

• The Plant Pathology Journal
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• 제24권4호
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• pp.439-446
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• 2008

A fungicidal spray program for effective control of three major apple diseases in Korea (white rot, bitter rot, and Marssonina blotch) was developed. This was based on our previous studies showing that application of ergosterol biosynthesis inhibitors (EBIs) in early or mid-August can eradicate white rot infection in fruit and that some protective fungicides show after-infection activity against white rot. The basic spray program focused on control of white rot, the main target disease, and the fungicides were sprayed at 15-day intervals from petal fall to late August using fungicides that show after-infection and EBI activity. The basic spray program was modified over 4 successive years to improve control efficacy against bitter rot and Marssonina blotch, which sometimes cause as much damage as white rot. Modifications to the regime were made every year by replacing one fungicide in the basic program at a specific spraying time. Substitution of only one fungicide in the spray program, even early in the growing season, greatly influenced the final disease incidence at harvest. Applying this principle, a moderately efficient spray program for cv. Fuji that increased the spray interval from 10 to 15 days and thus reduced the number of sprays required per crop season was developed.

• The Plant Pathology Journal
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• 제30권1호
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• pp.102-108
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• 2014

The bacterial strain T-9, which shows strong antifungal activity, is isolated from the soils of Samcheok, Gangwondo and identified as Paenibacillus kribbensis according to morphological and taxonomic characteristics and 16S rRNA gene sequence analysis. The P. kribbensis strain T-9 strongly inhibits the growth of various phytopathogenic fungi including Botrytis cinerea, Colletotricum acutatum, Fusarium oxysporum f. sp. radicis-lycopersici, Magnaporthe oryzae, Phytophthora capsici, Rhizoctonia solani, and Sclerotium cepivorum in vitro. Also, the P. kribbensis strain T-9 exhibited similar or better control effects to plant diseases than in fungicide treatment through in vivo assays. In the 2-year greenhouse experiments, P. kribbensis strain T-9 was highly effective against clubroot. In the 2-year field trials, the P. kribbensis strain T-9 was less effective than the fungicide, but reduced clubroot on Chinese cabbage when compared to the control. The above-described results indicate that the strain T-9 may have the potential as an antagonist to control various phytopathogenic fungi.

• The Plant Pathology Journal
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• 제20권1호
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• pp.75-80
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• 2004

In an attempt to develop effective biocontrol system for management of stem rot disease in groundnut, 57 bacterial isolates and 13 isolates of Trichoderma spp. were evaluated for their antagonistic activity against Sclerotium rolfsii. The antagonists were selected based on their ability to inhibit the external growth of S. rolfsii from infected groundnut seeds. Four isolates of Pseudomonas fluorescens, GB 4, GB 8, GB 10 and GB 27, and T. viride pq 1 were identified as potent antagonists of S. rolfsii. T. viride pq 1 produced extracellular chitinase and parasitized the mycelium of S. rolfsii. Under controlled environment conditions, P. fluorescens GB 10, GB 27, T. viride pq 1 and the systemic fungicide Thiram(equation omitted) reduced the mortality of S. rolfsii inoculated to groundnut seedlings by 58.0％, 55.9％, 70.0％ and 25.9％, respectively compared to control. In vitro growth of P. fluorescens GB 10 and GB 27 was compatible with T. viride pq 1 and Thiram(equation omitted). Integrated use of these two bacterial isolates with T. viride pq 1 or Thiram(equation omitted) improved their biocontrol efficacy. Combined application of either GB 10 or GB 27 with T. viride pq 1 was significantly effective than that with Thiram(equation omitted) in protecting groundnut seedlings from stem rot infection.

• 식물병연구
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• 제14권2호
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• pp.95-101
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• 2008

오이 흰가루병 저항성 검정을 위한 시험조건을 설정하고, 경기지역 오이 주산단지에서 분리한 흰가루병 병원균의 약제 저항성 정도와 흰가루병 방제농약의 서로 다른 계통별 저항성을 검정하기 위해 시험 약제를 농도별로 오이 잎에 살포한 잎 디스크 위에 채집한 병원균을 접종 배양하여 $7{\sim}9$일 후에 현미경을 이용, 발병도를 조사하였다. difenoconazole에 대한 약제 감수성 정도를 조사한 결과 평택 분리주들은 대체로 중도저항성이었으나, 2005년 오산에서 분리한 2개 균주들은 $300{\mu}g/ml$ 농도에서도 발병도가 높게 나타나 저항성 균주로 판단되었다. fenarimol에 대한 약제 감수성 정도는 평택, 오산, 용인 3지역이 대체적으로 중도저항성 또는 감수성으로 나타났으나, 오산에서 분리한 1개 분리주에서 $300{\mu}g/ml$에서도 발병하여 저항성 균주로 판단되었다. strobilurin 계통 농약에 대해서는 대부분 저항성으로 나타났으며, $1,000{\mu}g/ml$과 $2,000{\mu}g/ml$에서도 발병도의 변화가 없었으며 kresoximmethyl에 대해서도 교차저항성을 나타내었다. carbendazim에 대한 흰가루병 채집 균주의 감수성은 $1,200{\mu}g/ml$에서도 발병하여 저항성을 나타내었다. 약제 계통별 오이 흰가루병 포장 시험 결과 잎 디스크시험에서 저항성을 보인 strobilurin 계통의 농약에 대한 방제가는 azoxystrobin이 41.2%, kresoxim-methyl이 29.6%의 낮은 방제효과를 나타내어 금후 사용량을 줄여야 할 것으로 판단되었다.

• 식물병연구
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• 제15권3호
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• pp.248-253
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• 2009

항균활성을 가진 키토산은 우리나라 포장에서 다양한 식물 방제와 식물 생장을 위해 넓게 사용하고 있다. 고분자와 저분자(키토올리고당)의 키토산 화합물을 혼합한 2가지 제제(SH-1, SH-2)에 대한 병 방제 효과를 Fulvia fulva에 의해 발생하는 토마토 잎곰팡이병에 대하여 비닐하우스에서 조사하였다. 두 제제(SH-1, SH-2)는 두 번의 포장 시험에서 병 방제에 대한 활성을 나타내었다. 두 제제의 예방적인 병 방제에 대한 활성은 합성농약인 thiophanate-M과 비교하여 수행하였다. 병 방제를 위한 제형의 활성유지는 살포 후 21일까지 지속되었다. 병 방제를 위한 키토산의 효과적인 농도는 1,200 mg a.i/L였다. 포트시험에서 키토산 제제는 600 mg a.i/L 농도에서 식물생장이 증진되었다. 결과적으로 키토산 제제는 토마토 잎곰팡이병방제를 위한 친환경제제로서 활력을 가지며 식물생장도 촉진하였다.

• Mycobiology
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• 제49권1호
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• pp.89-94
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• 2021

Forty-three (n = 43) endophytic fungi with different morphologic characteristics were from a medicinal plant Sceletium tortuosum, were utilized to investigate their antifungal effectiveness against pathogenic fungi. All fungal isolates exhibited antifungal activity against one or more pathogens in the dual culture test whereas only 33 fungal culture filtrates (77%) showed decent antifungal effect. Fusaria and Aspergillus were the dominate genus that displayed significant antifungal activity. Isolates GG02, GG09, ND15, and ND17 showed the broadest spectrum of antifungal activity. Furthermore, culture filtrate of Fusarium sp. DR08 exhibited a broad range of antifungal activity against all the pathogens. The results suggest endophytic fungi isolated from medicinal plant might be a source of novel bioactive molecules. To the best our knowledge, this is the first report on endophytic fungi isolated from native kougoed exhibiting antifungal activity against plant fungal pathogens.

• 농약과학회지
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• 제19권3호
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• pp.323-328
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• 2015

식물세균병 방제에 사용되는 3종의 동 살균제, 3종의 항생물질계 살균제, 그리고 1종의 quinolone계 살균제를 선발하여 풋마름병균인 Ralstonia solanacearum에 대한 생장 억제 효과와 고추 유묘에서의 병 방제 효과를 조사하였다. NA배지 상에서 실시한 생장 억제 실험에서 oxytetracycline은 가장 우수한 효과를 보였는데, $1000{\mu}g\;mL^{-1}$ 처리에서 저지원의 크기가 14.95 mm로 가장 크게 나타났으며 $8.0{\mu}g\;mL^{-1}$ 처리구에서도 0.91 mm 크기의 저지원을 확인할 수 있었다. Validamycin은 병원균 생장에 대한 억제효과가 전혀 없었다. 동 살균제들은 copper hydroxide, copper oxychloride+dithianone, copper sulfate의 $1000{\mu}g\;mL^{-1}$ 처리구에서 각각 2.19, 1.30, 1.48 mm의 저지원이 나타났을 뿐 큰 효과를 보이지 않았다. 유묘 검정을 위해서 토양에 살균제를 관주처리하였을 때, 실내 검정에서 가장 효과가 우수하였던 oxytetracycline이 병원균을 접종하고 7일 후까지 모든 처리 농도에서 시들음 증상이 전혀 관찰되지 않아 100%의 아주 우수한 방제효과를 보였으나, 14일 후에는 $5000{\mu}g\;mL^{-1}$의 처리구에서부터 효과가 감소하였다. 3 종의 동 살균제는 7일 후에 $2000{\mu}g\;mL^{-1}$에서 90%의 효과를 보여 다른 살균제보다 낮은 효과를 보였으며, 14일후에는 copper sulfate를 제외한 2종의 살균제에서는 $500{\mu}g\;mL^{-1}$ 처리구에서 효과가 40% 이하로 감소하였다. 결과적으로 R. solanacearum에 의한 풋마름병의 방제를 위해서는 동 살균제보다는 항생물질계 살균제 또는 quinolone계 살균제 중에서 선발하여 사용하는 것이 타당할 것으로 생각된다.