The infection rate of soybean black root rot disease caused by Calonectria crotalariae was about . The isolated fungi from the infected soybean roots and stems were Calonectria crotalariae, Fusarium solani, F. roseum, Phomopsis sojae, Pythium aphanidermatum, Rhizoctonia solani and Macrophomina sp. Among them, C. crotalariae was the most virulent pathogen under the laboratory conditions. Mycelial growth and microsclerotial formation were good on PSA containing 1000cc of water, 100g of potato and 20g of sugar. Mycelial growth, sporulation and microsclerotial formation were good on sterilized root. Perithecial formation was better in the dark condition than in the light. Survival of macroconidia was not available between soil water content. Microsclerotia and mycelium in infected plant debris were survived for 4 months at to soil water content. The plant height, when inoculated with inoculum density, reached approximately half of uninoculated plants. Disease severity was much higher at nonsterilized soil than completely sterilized soil. It was determined that the host range of this pathogen includes soybean, peanut, green bean and red bean.

1. 동상해 (수부병)의 원인은 수확기의 강설과 저온(동상과율 수확직후 , 피해과의 폐기) 2. 동상해는 금팡이병류의 유발과 피해의 증대 요인(이병과율, 동상과, 부패감모량 ) 3. 발생 병해는 녹색, 청색, 회색 곰팡이와 균핵병등 (녹색, 청색, 회색 균핵기타 ) 4. 피해는 1톤당 로 135kg/톤의 부패로 손실액 27만원톤(해태 2,000톤중 55.2백만원, 제주도 5,000톤중 135백만원) 5. 방제는 조기선과 및 축하와 예조, 약제처리 등으로 부패 억압(발병과 부패는 10일내에 증대, 예조로 10일간, 약제로 20일간 억제)

감자 저장병으로서 중요한 Fusarium solani, F. roscum, F. oxysporum 및 Erwinia carotovora를 분리 동정하고 수확후에 공시품종 Epicure, Irish Cobbler, 및 Superior의 괴경을 절단하여 각 온도의 습실에 1, 3, 5, 및 7일간 예치한 후 suberin 및 periderm 형성을 검경하였다. 그리고 위와 같이 처리한 괴경에 4종의 병원균을 접종하여 9일간 정치한 후 부패도를 조사하였다. 예치온도가 높을수록 또 그 기간이 길어짐에 따라 보호막으로서의 suberin 및 periderm 형성이 증가하였으며 부패는 감소되었다. 공시균종간의 병원성, 품종에 대한 반응, 보호막 형성에도 차이가 있었으나 예치온도 및 기간의 효과가 부패방지에 더 중요하였다. 에서는 7일이내의 예치기간에 보호막은 거의 형성되지 않았으며 부패는 심하였고 에서는 대체로 이와 반대하였다. 그러므로 절상감자를 바로 에 냉장함은 피해여야 할 것으로 본다. 에서 3일 에서 5일이 지나면 부패되지 않았으며 suberin 및 periderm 형성은 중정도였다. 고온에서는 예치, 기간중에 기경이 부패되는 수도 있으므로 그 적온을 피하여 에 5일 이상 예치한 후에 저장하는 것이 실용적이라 생각된다.

우리나라에서 Phytophthora capsici균에 의한 가지의 병해는 아직 그 발생이 보고되어 있지 않다. 근래 수원을 포함한 중부지방에 P. capsici균에 의한 피해과가 채집되어 기록병해인 P. parasitica균에 의한 솜털역병과 그 병징, 병원성 및 병원균의 형태등을 비교 검토하였다. 본 병은 9월 강우가 있은 후 발생이 심하였으며 처음 과면에 원형갈색의 병반이 나타나 점차 확대되면서 그 위에 짧은 균계와 분생자경이 밀생하고 유주자양이 풍부히 형성되어 솜털모양으로 공중균계가 길게 자라고 유주자양이 거의 형성되지 않는 솜털병역과는 구별되었다. 그리고 병원균의 형태 및 병원성에 있어서도 뚜렷한 차이를 볼 수 있었다. 따라서 본 병원균은 P. capsica임을 확인할 수 있었으며 미기록인 본병해에 대하여 가지갈색썩음병이라는 이름을 붙이기로 하였다.

1. 포장에서 벼, 잎집썩음병 이병율은 일본형장려품종에는 거의 전무였으나 대체로 인도형품종 및 IR계통 또는 품종은 경-중도였다. 모든 공시품종 또는 계통은 종자에 접종하면 감염되었다. 실내에서 종자접한 결과는 몇 예외를 제외하고 포장에서의 이병율과 대체로 비슷하였다. 2. 벼, 잎집썩음병균의 배양여액은 벼, 보리, 밀, 호밀, 유채의 초엽 및 유근의 생육을 억제하였다. 특히 벼품종 통일은 진흥보다 현저히 초엽 및 유근의 생육이 억제되었다. 3. 병균 배양여액은 도열병균의 포자발아를 억제하였으나 깨씨무늬병균에는 영향이 없었다.

인삼뿌리썩음병균, Cylindrocarpon destructans(Zins.) Scholten을 접종한 인삼절편으로 부터 얻은 섬유소분해효소 및 펙틴질분해광소의 역가는 그 농도, 시간에 비례하였다. Cellulase (Cx), endo-polygalacturonase(endo-PG), endo-poiymethylgalacturonase (endo-PMG), exo-polygalacturonase (exe-PG)와 exo-polymeth-ylgalacturonase(exo-PMG)의 역가는 접종후 4 일째 최대였으며 endo-PG와 endo-PMG는 1일 및 2일째는 전혀 검출되지 않았으나 exo-PG와 exo-PMG는 검출되었다. 접종후 6 일째에는 모든 펙틴질분해효소는 활성을 완전히 잃었으나 섬유소분해효소는 높은 역가을 유지하였다. Cx, endo-PG, endo-PMG, exo-PG 및 exo-PMG의 최적 pH는 각각 6.0, 5.5, 8.0, 7.0-7.5, 8.5이였다. Cx, endo-PG, endo-PMG, 및 exo-PG의 최적온도는 각각 exo-PMG 였다. 섬유소분해효소는 공시한 16개 이온중에서 0.05M 만이 억제하였다. 펙틴질분해효소는 이온에 따라 상이하였으나 과 이 가장 현저히 억제하였다. 공시한 8개 농약중에서 어느 것도 유효성분으로는 모든 효소작용을 억제하지 못했으며 exo-PG만은 모든 농약의 의하여 상당히 억제되었다. 그 중에서 Difolatan은 모든 펙틴질분해효소를 가장 잘 억제시켰다. 과 은 펙틴질분해효소를 거의 억제시켰으나 섬유소분해효소는 같은 농도에서 각각 에 이르렀다. Formalin은 exo-PG와 endo-PMG를 완전 억제시켰으나 다른 효소 특히 Cx는 그렇지 못했다. Difolatan은 모든 효소를 이상 억제하였으나 Cx는 그 이하였다. C. destructans가 분필하는 섬유소분해효소 및 펙틴질분해효소는 인삼뿌리썩음병과 밀접한 관계를 가지고 있으며 이 병을 효과적으로 방제하기 위하여 억제되어야 하겠다.

1. "과피원판저지대법"으로 사과 탄달병 방제약제의 지속성, 전착제 및 살충제혼용의 효과를 검정하였다. 2. 살균제를 뿌린 후 시일이 경과할 수록 살균력은 줄었다. 공시 약제 중에서 Difolatan의 약효가 가장 컸으며 15일 후에도 의 살균력이 있었고 그 다음은 Tuzet, Phaltan, 보르도액 , Delan의 순위였다. 3. 인공강우량이 많을수록 Tozet의 약효는 줄었으나 전착제를 첨가함으로색 약제의 유실을 경감할 수 있었다. 시판 상품인 리노 1,2호 및 Tween 20 보다도 탈지분유 및 콩추출액의 효과가 현저히 좋았다. 4. Phaltan을 단용하는 것보다 EPN, Folithion, Parathion 및 Lebaycid 를 섞어서 실온에 12일간 두어도 어느 것이나 살균핵과에는 현저한 차이가 없었다.

Tomato 즙배지에서 도열병균의 분생포자형성 및 균사의 생장에 환경요인이 주는 영향을 연구하고자 우선 광선조사조건(광원, 조사광선의 색, 조사시간), 전배양기간, 배지의 산도 등에 관하여 조사함으로써 간편한 방법으로 단시일내에 병원균의 분생포자를 다량 생성시킬 수 있는 방법을 모색코자 본실험을 하였다. (1) 24시간 계속 형광등에 조사시킨 것이 암처리한 것이나, 주기적으로 조사한 것보다 분생포자생장 및 균사생장을 증가시켰다. (2) 무피복, 적색, 황색, 청색의 Cellophane을 투과시킨 형광등조사에서 무피복이 가장 분생포자형성이 많았고 적색 및 황색, 청색 순으로 감소하였으며 균사생장에는 유의차가 없었다. (3) 도열병균도 광선의 주기적인 조사에 의하여 광선의 색에 관계없이 수상생장을 나타냈다. (4) 전배양기간이 길수록 광선조사에 의하여 분생포자의 형성은 증가되었지만 48시간에서 가장 좋았다. (형광등구). (5) 균총의 착색정도와 공중균사의 발달정도는 분생포자형성과 밀접한 관계가 있는 것 같으며 암색일수록 분생포자의 생장은 많으며 공중균사가 많으면 분생포자생성은 감소하는 경향이 있었다. 24시간 계속조사시킨 것이 가장 암색을 나타냈고 주기적인 광선조사는 중간정도였다. (6) pH 5-9에서 분생포자 및 균사생장을 볼 수 있었는데 그 최적은 pH 7이었으며 pH4 이하의 산도에서는 전연 병균의 생장을 볼 수 없었다.

(1) 위조독소(Fusaric acid)를 생성하는 참깨, 시들음병균(Fusarium oxysporun f. vasinfectum)의 배양여액이 참깨, 밀, 목화, 벼 등의 종자의 발아에 미치는 영향을 구명하기 위하여 본시험에 착수하였다. (2) 공시균의 10종의 계통의 배양여액을 첨가한 발아상에 있어서의 참깨, 목화, 밀, 벼 등의 종자의 발아상태를 조사한 결과 공시균의 몇 가지 계통의 배양여액은 이들 작물종자의 발아에 뚜렷한 경향을 주지 않지만 대부분의 계통의 배양여액은 참깨, 목화, 밀, 벼 등의 종자발아를 완전히 조지하거나 혹은 발아지연 또는발아율의 저하를 초래한다는 것을 알았다. a. 공시균의 10종의 계통중 201호균의 배양여액은 참깨, 목화, 밀, 벼 등의 종자발아를 거의 완전히 저지하고 있으며 발아를 유제하는 독성에 있어서 작물간차이는 볼 수 없었으나 이 밖의 281, 321호균 등의 배양여액은 참깨, 목화. 밀, 벼 등 종자의 발아를 억제하는 독성에 있어서 작물간 차이를 볼 수 있었다. b. Fusarium oxysporum f. vasinfectum의 첩양여액이 종자발아를 억제하는 독성에 대하여 참깨가 가장 감수성이 강하고 벼는 감수성이 가장 약하며 밀, 목화 등의 감수성은 참깨와 혀의 그것의 중간에 속한다. (3) Fusarium oxysporum f. vasinfectum 여러 가지 계통균이 혼재하는 토양에서는 밀, 벼 등 비기주작물도 이 균이 토양중에 생성하는 Fusaric acid에 의하여 종자발아나 발아후의 생육이 저해될 가능성이 있다.

Sclerotinia rot, caused by Sclerotinia sclerotiorum, is a devastating disease that poses a serious threat to perilla production in Korea. Identifying effective sources of resistance offers long term prospects for improving management of this disease. Screening disease resistant genetic resources is important for development of disease-resistant, new cultivars and conduct related research. In the present study, perilla germplasm were screened in vitro against S. sclerotiorum using detached leaf method. Among 544 perilla accessions, two were highly resistant (IT226504, IT226533), five were resistant (IT226561, IT226532, IT226526, IT226441, and IT226589), five were moderately resistant (IT226525, IT226640, IT226568, IT220624, and IT178655), 16 were moderately susceptible, 31 were susceptible, and 485 were highly susceptible. The resistant accessions in this study could serve as resistance donor in the breeding of Sclerotinia rot resistance or subjected to selection procedure of varietal development for direct use by breeders, farmers, researchers, and end consumers.

Ginseng (Pnanx ginseng C. A. Meyer) is famous worldwide, and is very important cash crop and medicinal herb in Korea. It takes four to five years to produce harvestable ginseng roots, and ginseng is attacked by several pathogens during cultivation. We investigated the disease rate caused by ginseng root rot from 6 years old ginseng cultivation fields (Chungnam; 9 fields, Chungbuk; 11 fields, Gangwon 5 fields). The highest disease severity was Dangjin D (2.9) and the lowest one was Gaesan C (0.6). Of the 625 isolations, 340 isolations were classified as Ilyonectria radicicola and Fusarium solani. Finally, genetic diversity of I. radicicola and F. solani was confirmed by sequence analysis. Among the I. radicicola group, I. mors-panacis, which is known as highly virulent pathogen, and I. liriodendri, I. robusta and I. cyclamicicola, which are weakly virulent pathogens, were identified. In the case of F. solani, it is divided into two groups, but it is necessary to conduct diversity research through genetic analysis and pathogenetic studies using various markers. Based on these results, it could be used as a basic data for control of ginseng root rot pathogens.

Background: Some phenolics detected in the soil may inhibit the seed germination and seedling growth of ginseng (Panax ginseng). This study investigated the effect of irrigation and ginseng root residue addition on the soil microbial community and root rot disease in 2-year-old ginseng. Methods and Results: Each 20 ℓ pot was filled with soil infected with ginseng root rot pathogens, and irrigated daily with 2 ℓ of water for one month. After the irrigation treatment, ginseng fine root powder was mixed with the irrigated soil at a rate of 20 g per pot. In descending order, NO3 −, electric conductivity (EC), exchangeable Na (Ex. Na) and K (Ex. K) decreased due to irrigation. In descending order, NO3 −, EC, Ex. K, and available P2O5 increased with the additon of ginseng powder to the soil. The abundance of Trichoderma crassum decreased with irrigation, but increased again with the incorporation of ginseng powder. The abundance of Haematonectria haematococca increased with irrigation, but decreased with the incorporation of ginseng powder. The abundance of Cylindrocarpon spp. and Fusarium spp., which cause ginseng root rot, increased with the incorporation of ginseng powder. The abundance of Arthrobacter oryzae and Streptomyces lavendulae increased with irrigation. The abundance of Streptomyces lavendulae decreased, and that of Arthrobacter spp. increased, with the incorporation of ginseng powder. Aerial growth of ginseng was promoted by irrigation, and ginseng root rot increased with the incorporation of ginseng powder. Conclusions: Ginseng root residues in the soil affected soil nutrients and microorganisms, and promoted ginseng root rot, but did not affect the aerial growth of ginseng.

Background : Plants cultivation is hindered by root rot, a major disease caused by the soil-born fungi. The ginseng-cultivated soil is one of the nutritious habitats for soil-borne microorganisms. Bacteria from ginseng-cultivated soil can increase plant growth by supplying nutrients and hormones as well as protecting against pathogenic fungal infections and induced systematic resistance. Methods and Results : The novel species DCY115T was isolated from ginseng-cultivated soil in Gochang province, Republic of Korea. The isolate was assigned to the genus Paraburkholderia due to its 16S rRNA gene sequence closely proximity to P. xenovorans LB400T (98.8%). Strain DCY115T is gram-negative, facultative aerobic, rod-shaped, non-flagellated, oxidase and catalase positive. The predominant isoprenoid quinone is ubiquinone Q-8. The genomic DNA G + C content is 61.3 mol%. Phenotypic tests and chemotaxonomic analysis place strain DCY115T in the genus Paraburkholderia. DNA-DNA hybridization values between strain DCY115T and closely related reference strains were lower than 51%. The DNA relatedness data in combination with phylogenetic and biochemical tests showed that strain DCY115T could not be assigned to any recognized species. Finally, strain DCY115T showed the plant growth promoting activities of siderophores production, phosphate solubilization, and antagonistic activity against root rot fungal pathogen Fusarium solani (KACC 44891T) and Cylindrocarpon destructans (KACC 44660T). Conclusion : The results support the novel strain DCY115T as a potential biocontrol agent against root rot fungal pathogen within the genus Paraburkholderia for which the name Paraburkholderia panacihumi is proposed. The type strain is DCY115T (= KCTC52952T = JCM32099T).

Background : In previous study, we reported Sclerotium rot caused by Sclerotium rolfsii in Ixeridium dentatum for the first time. This experiment was conducted to select highly effective pesticides against Sclerotium rot caused by S. rolfsii in I. dentatum. Methods and Results : The chemical efficacy and the injury test were carried out. A total of five pesticides were used for the experiment test. For the efficacy test, we investigated spore germination and mycelial growth inhibiting ability by each pesticides in vitro and disease inhibiting ability in the field. For the chemical injury, we investigated appearance of abnormalities on condition of reference amount and fold amount in the field. In vitro, three kinds of chemicals such as Fludioxonil suspension concentrate (SC), Tebuconazole suspension concentrate (SC), and Flutolanil emulsifiable concentrate (EC) showed complete spore germination inhibitory effect, However in two chemicals such as Pyraclostrobin water-dispersible granule (WG) and Pyribencarb suspension concentrate (SC), the mycelial growth inhibitory effect was partially recognized but the spore germination was not inhibited. In the field, we performed an artificial inoculation experiment using sclerotia. As a result four kinds of chemicals such as Fludioxonil SC, Tebuconazole SC, Flutolanil EC, and Pyraclostrobin WG showed control value of above 80% against Sclerotium rot caused by Sclerotium rolfsii except Pyribencarb SC. Also there was no chemical injury in reference amount and in fold amount respectively, compared to non treated control. Conclusion : From the above results, we selected four items of pesticides including Fludioxonil SC, Tebuconazole SC, Flutolanil EC, and Pyraclostrobin WG as effective chemicals against Sclerotium rot caused by Sclerotium rolfsii in Ixeridium dentatum.

Background : The causative organism of Astragalus membranaceus (Hwanggi) root rot disease was known as Pythophthora drechsleri. In this study, a new species of root rot causative organism has been identified and reported. Methods and Results : Hwanggi, which has root rot disease, was collected in Jungsun-gun, Gangwon-do. The diseased root was cut into 1 ㎝ size and disinfected with 1% sodium hypochlorite solution for 1 minute and washed with sterile distilled water. The dried samples were dipped in the PDA medium and cultured in at 25℃ incubator. The 21 isolates were cultured under the same conditions and genomic DNA was extracted. The genomic DNA of isolated strains was extracted using a kit of Biofact. The isolated strains were identified using internal transcribed spacer (ITS) region sequencing. The ITS region was amplied using the primer pair ITS1 (5’-TCCGTAGGTGAACCTGCGG-3’) and ITS4 (5’-TCCTCCGCTTATTGATATGC-3’). The PCR was performed in a final volume of 50 ㎕ containing 10 mM Tris-HCl (pH 8.3), 50 mM KCl, 1.5 mM MgCl2, each dNTP at a concentration of 0.2 mM, 1.25 IU of Taq polymerase, each primer at a concentration of 10 pmol, and 2ul of the DNA template. Sequencing was performed by asking Macrogen. The analyzed sequences were compared using the Blast program provided by NCBI. As a result of identification of 21 strains, 13 Fusarium spp., 1 Peronospora sp. (causative organism of downy mildew), 3 Acremonium spp., 3 Uncultured fungus, 1 Phyrtophthora sp.. The main pathogen of wilt disease was known as Fusarium sp., a soil-borne pathogen. After analyzing the systematic taxonomic relationships, the systematic diagram was created using the neighbor-joining method. Conclusion : We have finally identified Phytophthora cryptogea as a causative organism of Hwanggi root rot disease and will check whether the disease has occurred on the inoculation through pot test.

Background : Development of new real-time PCR diagnosis method for simultaneous diagnosis of Cylindrocarpon destructans and Fusarium solani, causative fungi of ginseng root rot disease. C. destructans and F. solani are known to be the major pathogens of ginseng root rot disease. Root rot caused by these pathogens is a disease that is difficult to control because the disease progresses slowly and it is difficult to diagnose early and even when symptoms of plant seeding are present, the disease is already spread in the roots. Diagnostic methods to detect the presence or absence of ginseng roots rot fungi in soil before ginseng cultivation are currently being used as a method for controlling. However, commercialized soil extraction kits and PCR diagnostics have cost, diagnostic time, and single diagnostic problems, and need to develop new diagnostic methods. Methods and Results : Primers and probes in the beta-tubulin 2 gene were designed for species-specific detection. In silico analysis, the detection rate of C. destructans was 100% and the detection rate of F. solani was 95%. The multiplex real time PCR optimization conditions including the internal control were established. The analytical sensitivity using positive samples was 10 copies/㎕ for C. destructans and 10 copies/㎕ for F. solani. As a result of performance comparison test with conventional PCR diagnosis methods, it was confirmed that the developed multiplex real time PCR method has the same or better performance in terms of sensitivity. In the developed soil extraction kit, the extraction time was reduced and the extracted DNA quality was improved, compared to the used soil extraction kit. Conclusion : From the above results, we expect that the developed C. destructans / F. solani multiplex real time PCR diagnosis method and soil extraction kit will be useful for real-time monitoring of ginseng root rot pathogenic fungi in the soil of ginseng cultivation area and diagnosis of suitability of ginseng cultivation area.

Background : Root rot is a major factors of replanting failure in ginseng cultivation. Some of the phenolics detected in the soil could inhibit the seed germination and seedling growth of ginseng. Methods and Results : Water of 2 ℓ was irrigated per pot (20 ℓ) into the soil infected with ginseng root rot pathogens for one month every day. After the irrigation treatment, the powder of ginseng fine root of 20 g per pot was mixed with the irrigated soil. NO3 -, electric conductivity (EC), exchangeable Na (Ex. Na) and K (Ex. K) were decreased in descending order by irrigation. NO3 -, EC, Ex. K, and available P2O5 were increased in descending order by incorporation of ginseng powder into soil. Trichoderma crassum was decreased by irrigation, but it was increased again by incorporation of powder. Haematonectria haematococca was increased by irrigation, but it was decreased by incorporation of powder. Cylindrocarpon spp. and Fusarium spp. causing ginseng root rot were increased by incorporation of powder. Arthrobacter oryzae and Streptomyces lavendulae were increased by irrigation. Streptomyces lavendulae was decreased, and Arthrobacter spp. was increased by incorporation of powder. Aerial growth of ginseng was promoted by irrigation, and ginseng root rot was increased by incorporation of powder. Conclusion : The residues of ginseng root in the soil affected soil nutrients and microorganisms, and promoted ginseng root rot, but did not affect the aerial growth of ginseng.

Background : When the Platycodon grandiflorum is applied before the rainy season, the increase of the incidence of the Platycodon grandiflorum root rot disease increases greatly. This experiment was carried out to reduce the incidence of rot root rot disease through the lodging protecting method. Methods and Results : Three-years-old Platycodon grandiflorum was subjected to four treatments with no treatment, net installation, cutting stem, and removing bud. No treatment was used as a control, and as a further control, netting was used in the Platycodon grandiflorum to set up a treatment with almost no lodging. In the case of cutting stem, the stem was cut off in the middle of June, leaving more than 60 ㎝ before flowering. In the case of removing bud, blooming just before, the bud was removed. As a result, the coverage rate was the highest at 36.9% in the non - treatment area in the middle of July after the rainy season and 0.4% in the net installation. Compared with the case of cutting a lot of stems, 12.7% of the stem was covered with stones, whereas the stalk was 31.8%, which was close to the untreated stomach. As a result of the change of morbidity rate per treatment, it showed a morbidity rate of 49.7% in case of net installation, compared with 60% or more morbidity rate in case of untreated. Conclusion : As a result, an anti-lodging technic has helped prevent the onset of root rot disease. Further research on how to prevent the lodging of Platycodon grandiflorum using cutting stem will be needed.

Background : Ginseng is an important agriculture plant in Korea. However, plant yield is reduced by pathogens. Cylindrocarpon destructans and Fusarium solani are responsible for root-rot and replant failure of ginseng in Korea. Because of root rot pathogen, the productivity decreased and repeated cultivation is difficult. Methods and Results : The number of Cylindrocarpon destructans and Fusarium solani in soils can be measured by real-time PCR. This methode makes it possible to select of land for caltivation of ginseng. The specific primers of C. destructans and F. solani were synthesized from β-tubulin region. The equation of the standard curve between the colony forming unit(cfu) and the Ct value in the C. destructans was y (Ct value) = -1.608X (cfu) + 39.325. The equation of the standard curve between the colony forming unit (cfu) and the Ct value in the Fusarium solani was y (Ct value) = -1.608X (cfu) + 39.077. This method makes possible to rapidly exactly measure the number of pathogens in soil. C. destructans, a ginseng root rot fungus, was detected in soil samples of 32 (16%) in soil samples. 35.5% of paddy field, 34.3% of paddy field, 64.1% of field, and 65.6% of paddy field were found in perennial plant. Conclusion : As a result, the major causative agent of ginseng root rot was Cylindrocarpon and the onset density was 102 cfu/g in soil. There was no significant difference in density between fusarium and disease.