버섯 폐배지로부터 분리한 방선균 균주 CA-23과 AA-65균주의 키틴 분해능력과 항균력 검정

심창기(Chang-Ki Shim),김민정(Min-Jeong Kim),김용기(Yong-Ki Kim),지형진(Hyeong-Jin Jee),홍성준(Sung-Jun Hong),박종호(Jong-Ho Park),한은정(Eun-Jung Han),김석철(Seuk-Chul Kim) 한국농약과학회 2015 농약과학회지 Vol.19 No.4

The purpose of this study was to estimate the chitinolytic and antifungal activity of Actinomycetes sp.isolated from waste mushroom media. In five kinds of waste mushroom media, Sinyeong mushroom and Yangsongi were the order of the population density of actinomycetes. Totally 91 chitinolytic isolates of Actinomycetes sp. were obtained from waste mushroom media. The isolates were categorized into 3 groups based on chitinolytic activity and antagonisms against Phytophthora capsici, Rhizoctonia solani, Sclerotinia sclerotiorum, Collectotrichum gloeosporioides, and Cladosporium cucumerinum in vitro. CA-23 was selected as a representative isolate of a group showing strong chitinolytic and antagonistic activities to all of the plant pathogens, while AA-65 was selected as a representative isolate showing no chitinolytic activities but strong antagonistic activities to the pathogens. CA-23 and AA-65 were highly effective on control of Phytophthora blight of hot-pepper, powdery mildew and scab of cucumber in a greenhouse tests. Among the isolates tested, CA-23 showed highest control efficacy, while AA-65 not only effectively controlled the diseases but also consistently increased plant growth and yield. Although the isolates are similarly affected on suppression of plant pathogens, the isolates could be differ from each other in modes of action. Further studies on mechanisms and practical applications are being progressed.

유기농자재인 황토유황합제의 약해 경감 및 흰가루병 방제효과

심창기(Chang-Ki Shim),김민정(Yong-Ki Kim),김용기(Yong-Ki Kim),홍성준(Sung-Jun Hong),김석철(Suk-Chul Kim) 한국농약과학회 2014 농약과학회지 Vol.18 No.4

The soluble loess-sulfur mixture allowed standing to remove insoluble component materials for five weeks after manufacturing. We decreased the pH level of soluble loess-sulfur mixture at pH 1.0 modified with decreasing 25% sodium hydroxide than original content. The pH ranges of soluble loess-sulfur mixture solutions were adjusted to pH 5.0-pH 11.0 (pH 1 unit) with brown rice vinegar (pH 2.8). The pH of original loess-sulfur mixture was about pH 13 and damaged the foliar parts and young leaves of tomato after twice application. These stock solutions can be diluted 500:1 with tap water to make a 0.05% working solution and were sprayed two times with 7 days interval to the leaf and stem of tomato, which were spontaneously infected with E. cichoracearum. Control efficacy of powdery mildew ranged from 85% to 90% at 7 days after first application. After second application, each loess-sulfur mixture solutions adjusted pH level significantly suppressed the powdery mildew disease in tomato. Consequently, loess-sulfur complex adjusted pH level with brown rice vinegar was suggested to be low in acute toxicity at all different pH values and suggested to use an agent for control of tomato powdery mildew in organic farming.

유기농업 생태계로부터 담수 녹조류 분리 및 형태적 동정

김민정,심창기,김용기,홍성준,박종호,한은정,지형진,윤종철,김석철,Kim, Min-Jeong,Shim, Chang-Ki,Kim, Yong-Ki,Hong, Sung-Jun,Park, Jong-Ho,Han, Eun-Jung,Jee, Hyeong-Jin,Yun, Jong-Chul,Kim, Suk-Chul 한국유기농업학회 2014 韓國有機農業學會誌 Vol.22 No.4

본 연구는 유기농업에서 생물자원으로서 담수 클로렐라의 활용 가능성을 연구하고자 유기농 생태계로부터 담수 녹조류를 분리, 동정하고, 생물학적인 특성을 조사하였다. 조사 지역의 수온은 $12.4{\sim}28.2^{\circ}C$, pH는 6.1~8.5이었다. 담수 녹조류를 분리할 때 고체배양법이 액체배양법보다 오염도가 낮고 분리 빈도가 높았다. 전국 9개 지역, 6개 담수 녹조류 서식처로 부터 총 115개의 균주를 분리하였다. 담수 녹조류의 분리 및 배양을 위해 질소원으로는 $NaNO_3$과 $KNO_3$, 탄소원으로 $Na_2CO_3$를 사용하였고, macro media의 구성 성분 중 $MgSO_4{\cdot}7H_2O$과 $CaCl_2{\cdot}2H_2O$를 분리하여 제조한 BGMM(BG11 Modified Medium)배지를 고안하였다. 담수녹조류는 배양 후 4일째부터 급격히 흡광도가 증가하였고 8일째부터 흡광도가 감소하였다. 공시한 7개의 균주 중 CHK008 균주가 배양 7일째에 가장 높은 흡광도를 보였다. 담수 녹조류 배양에 적합한 BGMM 배지의 pH는 6~7이었고 조사되는 빛이 강할수록 생육이 증가하였으며 5종류 당류 중에서 Glucose와 Galactose를 첨가하였을 때 클로랄라의 생육이 좋았다. 순수 분리한 16개 녹조류 균주의 균총색은 녹색, 진녹색, 연녹색을 나타내었고, 11개의 균주가 형광현미경하에서 강한 형광 빛을 나타내었다. 녹조류 16개 균주의 형태적인 특징을 조사한 결과 C. vulgalis, C. sorokiniana, C. pyrenoidosa, C. kessleri, C. emersonii, and Chlamydomonas sp.의 2개 속 6개종으로 동정되었다. 담수 녹조류의 세포 크기는 종마다 다양한 변이를 보였다. 대부분의 담수 녹조류의 세포형태는 구형이었다. Chlamydomonas sp.는 타원형이었고 Chlorella sorokiniana는 구형과 타원형이 섞여 있었다. 6개 녹조류 종류 중 Chlamydomonas sp.를 제외한 모든 균주는 편모가 없었다. Chlamydomonas sp. 1개 균주와 C. sorokiniana 5개 균주는 세포에서 점질물을 분비하였다. This study aimed to isolate and identify freshwater algae from the organic agricultural ecosystems and investigate its biological characteristics to study the possibility of utilizing a biomass freshwater algae in organic farming. In the survey area, average water temperature was $12.4{\sim}28.2^{\circ}C$ and the pH ranges were from 6.1 to 8.5. The solid culture method is more suitable than liquid culture method for isolation of freshwater algae with lower contamination level and higher isolation frequency. A total of 115 strains were isolated from six freshwater algae habitats in nine regions in Korea. BGMM (BG11 Modified Medium) amended with NaNO3 and $KNO_3$ as a nitrogen, and $Na_2CO_3$ as carbon source was designed to isolate and culture freshwater algae. Absorbance of freshwater algae culture has increased dramatically to four days and decreased after eight days after inoculation. CHK008 of the seven isolates showed the highest absorbance in seven days after culturing in BGMM. The optimal pH of BGMM for culturing freshwater algae was pH 6-7. As light intensity increased, growth of freshwater algae increased. Among the five kinds of carbon sources, glucose and galactose promoted good growth of freshwater algae in BGMM. The colony color of purified 16 green algae isolates showed a separation of green, dark and light green, and of them, eleven algae strains showed a strong fluorescent light under fluorescence microscopy. Cell size of the green algae showed a wide range of variation depending on the species. General morphology of the green algae strains was spherical. Chlamydomonas sp. was elliptical, and Chlorella sorokiniana was ellipsoidal and cylindrical. All strains of the green algae except for Chlamydomonas sp. did not have flagella. One isolate of Chlamydomonas sp. and five isolates of C. sorokiniana secreted mucus. Sixteen isolates of 16 green algae were identified as two family and six species, Chlorella vulgalis, C. sorokiniana, C. pyrenoidosa, C. kessleri, C. emersonii, and Chlamydomonas sp. based on their morphological characteristics.

간.혼작을 이용한 유기농 배추 주요해충 발생경감 효과

김민정,심창기,김용기,지형진,윤종철,박종호,한은정,홍성준,Kim, Min-Jeong,Shim, Chang-Ki,Kim, Yong-Ki,Jee, Hyeomng-Jin,Yun, Jong-Chul,Park, Jong-Ho,Han, Eung-Jung,Hong, Sung-Jun 한국유기농업학회 2013 韓國有機農業學會誌 Vol.21 No.4

본 연구는 유기농 배추재배를 위한 주요 해충 방제를 위한 push-pull 전략 수립을 하고자 유인 또는 기피식물의 효과를 평가하였다. 2012년 충남 서산의 유기농 배추재배농가에서 발생하는 배추좀나방, 배추잎벌레, 진딧물, 비단노린재 및 갈색노린재에 대한 메리골드, 호밀, 부추, 상추, 치커리, 농우-치커리, 쑥갓, 트레비소 및 겨자채 등, 9가지의 식물에 대한 유인 또는 기피효과를 평가하였다. 10종의 유인 및 기피식물 중에서, 호밀과 치커리는 갈색날개노린재와 비단노린재를 각각 강하게 유인하였다. 진딧물은 다른 식물보다 호밀에 선택적으로 유인되었다. 겨자채는 비단노린재, 갈색날개노린재 순으로 유인하였다. 비단노린재는 상추와 부추 혼작처리에 유인되었다. 유기농 배추포장에서 쑥갓, 트레비소, 청겨자의 단독 또는 혼합처리는 배추잎벌레, 배추좀나방, 비단노린재, 진딧물, 갈색날개노린재의 발생을 강하게 기피하였다. 상기 결과들은 선발한 해충 유인 및 기피식물은 배추의 종합적 해충방제를 위한 인자로 사용할 수 있을 것으로 사료된다. This study was evaluated the effect of attractant or repellent plants for establishing push-pull strategy for insect pest management of organic Chinese cabbage cultivation. The attractant or repellent effect of Ten plants, marigold, rye, Chinese chive, lettuce, chicory, Nongwoo-chicory, crown daisy, Treviso, green leaf mustard, and red leaf mustard were evaluated against diamondback moth, striped flea beetle, aphids, brown-winged stink bug and cabbage stink bug in organic Chinese cabbage field in Seosan in 2012. Of the ten repellent or attractant plants, rye and chicory attracted significantly brown-winged stink bug and cabbage stink bug, respectively. Aphids ate attracted significantly to the rye rather than the other plants. Leaf mustard was attracted cabbage stink bug and brown-winged stink bug in order. Cabbage stink bug was attracted by only a combination of lettuce and Chinese chive. Diamondback moth, striped flea beetle, aphid, brown-winged stink bug and cabbage stink bug were significantly repelled by single or combined cultivation of crown daisies, Treviso, and leaf mustard in organic Chinese cabbage cultivation. The results above-mentioned indicate that selected insect-attractant and -repellent plants can be used as tools for integrated pest managements of Chinese cabbage.

마요네즈 살포에 의한 오이흰가루병 방제

김진경,심창기,박상원,박병준,지형진,김원일,권오경,임건재,Kim, Jin-Kyoung,Shim, Chang-Ki,Park, Sang-Won,Park, Byung-Jun,Jee, Hyeong-Jin,Kim, Won-Il,Kwon, Oh-Kyung,Im, Geon-Jae 한국유기농업학회 2009 韓國有機農業學會誌 Vol.17 No.4

시판 마요네즈를 이용하여 오이 흰가루병에 대한 방제효과를 시험하였다. 마요네즈를 0.5~2% 농도로 물에 희석하여 흰가루병이 발병된 오이에 6일 간격 3회 처리했을 때 8.3~99.2% 방제효과를 나타내었다. 90% 이상의 방제효과를 보인 마요네즈 희석액 중 2-3엽의 어린모에서 약해가 없었던 농도는 0.5%이었다. 마요네즈 중 기름함량이 78~80% 수준인 일반 마요네즈와 기름함량을 38~70%로 줄인 저지방 마요네즈의 흰가루병 방제력을 비교했을때 저지방 마요네즈는 방제율은 39.3~59.8% 수준으로 일반마요네즈에 비해 방제율이 떨어졌다. 마요네즈가 처리된 잎의 엽록소 함량은 발병구에 비해 엽록소 함량이 약 3배 정도 높게 조사되어 처리된 마요네즈가 오이 잎의 광합성을 저해하지 않으면서 흰가루병을 효과적으로 방제함을 확인하였다. This study was conducted to develop an organic control of powdery mildews of cucumber by using mayonnaise in green house. The treatment of 0.1~2% mayonnaise resulted in 8.3%~99.2% control efficiencies against powdery mildew of cucumber. 0.5% mayonnaise treatment resulted control values over 97% in disease. It did not adversely affected the photosynthesis of foliages. Although one application of mayonnaise to the foliage was not practically effective enough, two or three application of mayonnaise to the foliage at the 0.5% concentration resulted in excellent control against powdery mildews. This treatment could provide protection for 10~14 days after application. Among the type of mayonnaise, general mayonnaise revealed 97.5% control value, but mayonnaise containing low oil content revealed 39.3%~97.5% control values on powdery mildews at the 0.5% concentration. Therefore, oil content in mayonnaise played a essential material to control powdery mildew. Results indicated that mayonnaise could be used as organic control of powdery mildews of cucumber. This control might be environmentfriendly as well as cost-effective.

국산 발효식품 추출물과 발효식품유래 미생물을 활용한 벼 종자전염성 진균병 방제

김용기(Yong-Ki Kim),홍성준(Sung-Jun Hong),심창기(Chang-Ki Shim),김민정(Min-Jeong Kim),이민호(Min-Ho Lee),박종호(Jong-Ho Park),한은정(Eun-Jung Han),최은정(Eun-Jung Choi),배수일(Soo-Il Bae),지형진(Hyeong-Jin Jee) 한국농약과학회 2014 농약과학회지 Vol.18 No.4

When we investigated seed infestation by fungal pathogens from 51 varieties in 9 crops, the contamination rate of rice and sesame seeds was high. Therefore, to control seed-borne diseases, we obtained extracts from commercial products of Kimchi, Gochujang, Doenjang, Ganjang, Makgeolli and Tohajut and their suppressive effects against seed-borne diseases were studied. In addition, bacterial strains were screened to control rice seed-borne diseases in vitro and in vivo. Among forty food extracts, eleven food-extracts suppressed incidence of seedling rots in vitro and five food extracts increased 8-33% of healthy seedling in the greenhouse. Among 218 isolates from 40 fermented foods, 43 isolates showed high antifungal activity against seven fungal pathogens. When we tested 43 isolates for the reduction of rice seed borne disease, 32 isolates were able to reduce the rice seed borne disease. Among 32 isolates, 17 isolates reduced significantly seedling rot and increased healthy seedlings, the other isolates except for Kc4-2 and Mkl 2-2 increased shoot emergence and the percentage of healthy plants. Thirty isolates with high antifungal activity and suppressive effect against rice seedling rots were identified by 16S rRNA sequencing. Twenty one of thirty isolates were identified as Bacillus spp. Three isolates from Makgeolli were identified as Saccharomyces cerevisiae. B. amyloliquifaciens were isolated from six Korean traditional fermented foods except for Ganjang. B. amyloliquifaciens were majority in the effective bacterial population of Gochujang and Jutgal. Relatively diverse Bacillus species including B. subtilis, B. pumilus, and B. amyloliquificiens were isolated from Kimchi. The selected effective microorganisms from Korean fermented foods founded to be effective for controlling seed-borne diseases of rice in vitro and in the greenhouse. We think that Korean fermented foods and their useful microorganisms can be used as biocontrol agents for suppressing rice seed-borne diseases based on above described results.

맥주와 담배 혼합액을 이용한 민달팽이 방제

윤종철,박종호,심창기,류경열,지형진,Yoon, Jong-Chul,Park, Jong-Ho,Shim, Chang-Ki,Ryu, Kyung-Yul,Jee, Hyeong-Jin 한국응용곤충학회 2007 한국응용곤충학회지 Vol.46 No.2

다양한 엽채류에 발생하며 특히 상추에 피해가 큰 민달팽이는 여러 가지 식품자재 중 맥주와 오이즙액에 가장 효과적으로 유인되었다. 하지만, 이들 재료는 민달팽이를 유인할 뿐 살충효과는 전혀 없었다. 민달팽이 유인재료에 살충효과를 나타내는 물질들을 첨가하였을 때 맥주와 담배가루 혼합액의 민달팽이 유인 포살효과가 가장 높았다. 맥주 50ml에 담배 1개비 가루를 혼합하여 작은 플라스틱 용기에 담고 지표면에 매몰한 결과 하룻밤 사이에 평균 25 마리의 민달팽이가 유인 포살되는 것으로 나타났다. 하지만, 민달팽이 유인효과가 높았던 오이즙액에 담배가루를 혼합한 처리구에서는 평균 4.3마리만 유살되었다. 맥주와 담배 혼합액을 민달팽이가 심하게 발생된 상추 재배하우스에 3일간 연속으로 처리한 결과 68.4%의 방제효과를 나타내었으며, 상추 육묘상에서는 58.3%의 방제효과를 보였다. 본 연구에서 개발된 트랩은 매일 작업을 해야 하는 번거로움이 있으나 민달팽이의 피해가 큰 친환경 유기농 채소 생산농가의 육묘장이나 본포장 등 제한된 면적에서는 활용가치가 높을 것으로 기대된다. Among various food base baiting materials, beer and macerated cucumber were the most effective to induce slug that is a troublesome pest on leafy vegetables, especially on lettuce. However, the baits attracted only but did not kill the pest. When the baits were combined with various insecticidal organic materials, a few combinations such as beer and cigarette mixture successfully induced and killed the slug in the field test. The most effective combination of beer 50ml and a cigarette contained in a small plastic box killed 25 slugs per night. While macerated cucumber 50ml and a cigarette mixture killed only 4.3 slugs. The bait of beer and cigarette mixture revealed 68.4% control value against slug damage when treated for 3 consecutive days in a lettuce cultivation greenhouse. The bait also effectively reduced the slug damage in a lettuce nursery showing 58.3% control value. The method seemed highly useful for the control of slug in the organic farming system in which application of pesticides are strictly prohibited.

저장기간 및 저장온도에 따른 미생물농약 및 친환경 유기농자재 유효미생물의 밀도변동

김용기(Yong-Ki Kim),홍성준(Sung-Jun Hong),지형진(Hyung-Jin Jee),심창기(Chang-Kee Shim),박종호(Jong-Ho Park),한은정(Eun-Jung Han),안난희(Nan-Hee An),이승돈(Seong-Don Lee),유재홍(Jae-Hong Yoo) 한국농약과학회 2011 농약과학회지 Vol.15 No.1

To work out quality control methods of environmental-friendly organic materials (EFOMs), the reason and basis for EFOM-selection and farmer's favorite formulation type of EFOMs, etc were investigated on farmers who had been practicing environmental-friendly agriculture. EFOMs used were soil amendments, control agents of plant diseases and insect pests, plant growth promotion formulations, in turns. In EFOMs application time, 22.7% of farmers sprayed EFOMs without delay after they were bought, in other hand, 77.3% of farmers used EFOMs which had been bought and stored for some period. Microbial density on seventeen environmental-friendly microbial formulates (EFMFs) including microbial pesticides, a microbial fertilizer, and environmental-friendly organic materials was investigated at different storing temperature and shelf life. When the microbial density of EFMFs was investigated without delay after they were bought, all used microbial pesticides and a microbial fertilizer was confirmed to be optimal for the certified density but two of environmental-friendly organic materials was confirmed not to be optimal. When microbial density of 17 EFMFs were investigated after storing them for six months at 4 ℃, only one of 9 microbial pesticides was confirmed not to be optimal, the other hand four of seven environmental-friendly organic materials not to be optimal, which each of their microbial density was less than the certified density. Population dynamics of microbial agents was much more influenced in fluctuated temperature (room temperature) than in static temperature condition (5℃ and 25℃). Shelf life of microbial agents according to microbial formulation type were high in granule type, liquid wettable type and liquid type in turns.

Paenibacillus polymyxa CW를 이용한 고추 및 토마토 흰가루병 방제

김용기(Yong-Ki Kim),최은정(Eun-Jung Choi),홍성준(Sung-Jun Hong),심창기(Chang-Ki Shim),김민정(Min-Jeong Kim),지형진(Hyeong-Jin Jee),박종호(Jong-Ho Park),한은정(Eun-Jung Han),장보경(Bo-Kyung Jang),윤종철(Jong-Cheul Yun) 한국농약과학회 2013 농약과학회지 Vol.17 No.4

In order to improve practical utility of agro-microorganisms (AMs) which had been cultured and disseminated to promote plant growth and to control crop diseases, 51 isolates of AMs were collected from 18 agricultural extension centers in local government and screened for multi-functions such as antifungal activity, activities of phosphorus solubilization, IAA and siderophore production, nitrogen fixation, and hydrolytic enzyme activity. Finally we selected one isolate showing good antifungal activity and multifunctions related to plant growth and disease control. The selected isolate, Paenibacillus polymyxa CW, showed good inhibitory effect against plant pathogens, Pyricularia gresea, Colletotrichum acutatum, Fusarium oxysporum, Phomopsis sp., Aspergillus niger, Rhizoctonia solani and Phytophthora capsici. Suppressive effect of P. polymyxa CW against the used plant pathogens except for R. solani was much higher than that of P. polymyxa AC-1 storing in National Academy of Agricultural Science. We found P. polymyxa CW isolate showed good activity in siderophore and IAA formation, and nitrogen fixation. With P. polymyxa CW isolate, siderophore formation activity was similar to that of P. polymyxa AC-1, but IAA formation and nitrogen fixation activity was much higher than that of P. polymyxa AC-1. However neither P. polymyxa CW nor P. polymyxa AC-1 showed hydrolytic enzyme (chitinase, pectinase and cellulase) activity. The treatment of P. polymyxa CW with culture suspension of different cell density (10<SUP>8</SUP>, 10<SUP>7</SUP>. 10<SUP>6</SUP> cfu/ml) showed that the highest density reduced incidence of red pepper powdery mildew by 68.3% after 10 days of application. As application density of P. polymyxa CW was decreased, its control efficacy was proportionally decreased. In addition, when P. polymyxa CW was treated to control tomato powdery mildew at the same concentrations and their control effects were investigated after 7 days of inoculation, disease incidence was 0.03, 19.5, 45.7%, respectively, compared to 56.3% that of untreated check. Like red pepper powdery mildew, increase of application density of P. polymyxa CW resulted in increase of its control efficacy proportionally. P. polymyxa CW showed a density-dependent control efficacy against red pepper and tomato powdery mildews. Therefore we think that mode of action of the antagonist for suppressing two powdery mildew diseases might be antibiosis and density of more than 10<SUP>8</SUP>cfu/ml was needed to control effectively the two diseases. On this basis, we think that P. polymyxa CW can be a promising control agent for suppressing powdery mildews of red pepper and tomato.

콩 품종, 파종시기 및 작부체계가 콩 불마름병 발생에 미치는 영향

홍성준,김용기,심창기,김민정,박종호,한은정,지형진,Hong, Sung-Jun,Kim, Yong-Ki,Shim, Chang-Ki,Kim, Min-Jeong,Park, Jong-Ho,Han, Eun-Jung,Jee, Hyeong-Jin 한국유기농업학회 2014 韓國有機農業學會誌 Vol.22 No.4

Xanthomonas axonopodis pv. glycines에 의해 발생하는 콩 불마름병은 콩을 재배하는 많은 지역에서 가장 많이 발생하는 세균성 병해 중 하나이다. 본 연구는 콩 불마름병 발생 억제를 위한 저항성품종, 파종시기, 작부체계에 대한 효과를 포장에서 평가하기 위하여 수행되었다. 100여 품종을 자연 감염된 포장에서 저항성을 평가한 결과 푸른콩 등 14품종이 저항성을 나타내었고 30여 품종이 병반면적률 3% 이하의 중간 저항성을 나타내었다. 또한 불마름병 감수성 품종인 태광콩을 5월 25일, 6월 5일, 6월 15일, 6월 25일 등 10일 간격으로 파종시기를 조절하여 병반면적률을 조사한 결과 23.3%-25.7%, 14.7%-18.0%, 10.7%-12.8%, 1.0%-2.7%의 발생을 각각 확인하였다. 불마름병 발생이 가장 낮은 처리구는 6월 25일 파종구였으며, 발생이 가장 심한 처리구는 5월 25일 처리구였다. 파종시기가 늦어질수록 불마름병 발생은 감소되는 것을 알 수 있었다. 2006년 12월부터 2007년 6월까지 5개의 콩-동계작물 작부체계의 토양을 채집하여 불마름병 병원균의 생존밀도를 조사하였다. 조사결과 모든 작부체계에서 병원균이 검출되었으며 콩-보리 작부체계와 콩-마늘 작부체계의 병원균 밀도가 다른 작부체계보다 생존밀도가 낮았다. 더욱이 두 개의 작부체계는 콩 불마름병 발생도 감소하는 것으로 확인되었다. Bacterial pustule of soybean caused by Xanthomonas axonopodis pv. glycines is one of the most prevalent bacterial diseases in many areas where soybeans are grown. This study was carried out to evaluate the effect of cultivars, sowing date and cropping system on the suppression of soybean bacterial pustule in the field. One hundred soybean cultivars were screened for disease resistance against bacterial pustule in naturally infested field. Among them, fourteen cultivars including 'Pureun' were found to be high resistant. And thirty cultivars showed to be moderate resistant(less than 3% of diseased leaf area). When Soybean cultivar 'Taekwang' were sown in four different dates, May 25, June 5, June 15, and June 25, at 10 day-interval in Milyang, the diseased leaf area of bacterial pustule was 23.3%-25.7%, 14.7%-18.0%, 10.7%-12.8%, and 1.0%-2.7%, respectively. The lowest percentage of diseased leaf area was recorded in the plots sown on June 25, whereas the highest percentage of diseased leaf area was recorded in the plot sown on May 25. As sowing time was delayed, incidence of soybean bacterial pustule found to be comparatively reduced. From December in 2006 to June in 2007, we surveyed the pathogen population of soybean bacterial pustule in five cropping upland soils where soybean was cultivated. The survey result showed the bacterial pustule pathogens were detected from the all cropping soils. The pathogen populations of soybean bacterial pustule in soybean-barley and soybean-garlic cropping soil were significantly lower than that of the other cropping soils. In addition, the incidence of soybean bacterial pustule was decreased under the two cropping systems.