• Korean Journal Plant Pathology
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• v.12 no.3
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• pp.377-379
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• 1996

1990이래 단감재배 면적이 확대되고 있는 경주 및 그 인근의 포장으로부터 이미 알려진 병징과는 전혀 다른 병징을 나타내는 병을 단감의 주요 품종인 부유의 이병 잎과 신초로부터 병원균을 분리하고 그 병원 곰팡이의 병원학적 특징을 조사하였다. 이 병은 신초선단부 잎에서 발생하여 아래잎으로 진전되며, 잎에는 잎가장자리나, 중앙부 등 일정한 부위가 없이 발병하여 회갈색의 둥근 무늬가 확대되기도 하고, 심하면 잎이 고사탈락하기도 한다. 심한 경우 병반의 크기가 전체 잎의 1/3이상을 차지할 정도로 크게 확대되었다. 신초는 병의 진전이 심해지면 고사함으로서 나무 생육이 급격히 중지되거나, 나무 수세가 떨어져 수확에도 지장을 주고 있다. 발생시기는 6월 중.하순~7월, 9~10월 초순까지 발병하며, 병든 잎과 가지를 채집하여 병원균을 순수 분리하여 Guba(1949년), Sutton(1969)와 Steyaert(1971)의 분류기준에 따라 동정한 결과는 다음과 같았다. 병원균의 분생포자의 크기는 23.1$\times$7.1 $\mu\textrm{m}$, color cell의 크기와 수는 15.65 $\mu\textrm{m}$, 3개이었고, 포자의 윗부분은 다갈색이었으며 아래부분은 올리브색이었다. Setrlae의 크기와 개수는 23.6 $\mu\textrm{m}$, 2~4(3)개이고, pedicle의 길이는 5.17 $\mu\textrm{m}$였다. 이상의 결과에 근거하여 이 병원균을 Pestalotiopsis theae로 동정하고 국내미기록병으로 보고한다.

• Research in Plant Disease
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• v.14 no.1
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• pp.26-31
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• 2008

Anthracnose caused by Colletotrichum spp. has been known as a significant disease which commonly infects to the fruits of Chinese matrimony (Lycium chinese) in the field conditions. To select effective fungicides for the control of Chinese matrimony anthracnose, the antifungal activity of 15 fungicides were evaluated with 13 different strains of Colletotrichum spp. in the laboratory condition. Six fungicides (Dithianon WG, Tebuconazole SC, Tebuconazole WG, Trifloxystrobin + Tebuconazole SC, Azoxystrobin SC and Polyoxin D zinc salt + Carbendazim WP) out of them, showed effective suppression with the mycelium growth of pathogenic fungus, and were selected to test in vivo of the field condition. Five fungicides, Dithianon WG, Tebuconazole WG, Trifloxystrobin + Tebuconazole SC, Tebuconazole SC and Azoxystrobin SC, were significantly effective to protect anthracnose of Chinese matrimony, the variety "Chungyang Jerae".

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.32-37
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• 2003

Bacterial soft rot by Erwinia carotovora subsp. carotovora is one of the diseases causing the biggest problem in Chinese cabbage. Chemical screening was conducted to select effective agents for controlling bacterial soft rot. Control effect of antibiotics, plant activator, and Biokeeper (avirulent Erwinia) to soft rot were tested by in vitro assay, nursery test, and field experiment. The in vitro assay was done by paper disc method and potato slice method. The nursery test was performed by using mineral oil inoculation method with consistent disease induction. The in vitro assay showed that streptomycin, oxolinic acid, bronopol, and copper hydroxide significantly suppressed the growth of pathogenic bacterium and the decomposition of potato slice. However, plant activators including acibenzolar-S-methyl did not show the suppressive effect on the growth of pathogenic bacterium and the decomposition of potato slice. When applied by the nursery test condition using mineral oil inoculation method with Chinese cabbage 'Kangruckyeurum', Biokeeper, oxolinic acid, antibiotics streptomycin, validamycin, and copper compound provided 83.5%, 95.2%, 91.2%, 57.5% and 79.9% in control efficacy, respectively. However, the control effect of acibenzolar-S-methyl showed to be low to cause phytotoxicity. Also acibenzolar-S-methyl showed a significant control effect in the field experiment with Chinese cabbage 'Sanchon' in 2000, but the field experiment with Chinese cabbage 'Kangruckyeurum' in 2001 revealed it had phytotoxicity to Chinese cabbage. Such a difference was considered to be caused by differences in phytotoxic reaction of Chinese cabbage cultivars to the chemical. Streptomycin+copper, copper hydroxide and Biokeeper showed 79.7%, 71.9% and 60.9% in control efficacy, respectively, in the field experiment with Chinese cabbage 'Sanchon' in 2002.

• Research in Plant Disease
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• v.17 no.3
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• pp.295-301
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• 2011

The effect of various fungicides on anthracnose of strawberry, caused by Colletotrichum gloeosporioides, was determined in vitro, and in greenhouse and field trials. The $EC_{50}$ values of benomyl were clearly different between two sensitive and resistant groups of isolates. Iminoctadine tris had lower $EC_{50}$ values than mancozeb and propineb as protective fungicides and the response of mancozeb, propineb and azoxystrobin was variable depending on the isolate. In the greenhouse, pre- and post- inoculation fungicide applications significantly reduced disease compared to the non-treated control. Propineb, mancozeb and azoxystrobin were effective in controlling the disease when applied prior to inoculation. Metconazole and prochloraz-Mn treatments as ergosterol biosynthesis-inhibiting fungicides had the lowest incidence of anthracnose. In the nursery field trials in 2009 and 2010, the reduced fungicide spray program provided similar levels of disease control compared to the calendar-based applications with captan. A reduced spray program based on efficacious fungicides such as prochloraz-Mn will be useful for strawberry growers and provide more options for controlling anthracnose in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.3
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• pp.199-203
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• 2006

In the late growth stage of rice plant, the growth declines even though they grow well in early growth stage. This phenomenon is called autumn declining and it often accompanies the infection of Helminthosporium leaf spot disease. This study was carried out to identify the related environmental factors and to establish the integrated control system of Helminthosporium Leaf Spot Disease in rice. The total area of infected paddy field by Helminthosporium leaf spot was 470 ha in 2000 and 1,004 ha in 2001, which occupied about 1% of the total paddy area in Gyeongbuk province, Korea. The ill-drained sandy paddy occupied 50% of the total area of infected paddy fields and followed by sandy paddy (28%). Comparing the content of soil elements between infected and normal paddy, it was clarified that the organic matter content of normal was higher than that of infected paddy and the contents of inorganic elements such as Mn, Fe, Zn and available $SiO_2$ were also higher in normal paddy. The results of comparing the inorganic elements between infected and normal rice plants also showed the same results. The contents of inorganic elements such as MgO, $SiO_2$, Fe, Mn were higher in normal rice plants. Especially highly significant difference of $SiO_2$ content on both soil and rice plants was noticeable.

• Research in Plant Disease
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• v.13 no.3
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• pp.152-156
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• 2007

Incidences of leaf blight of lily cultivars Raizan and Casa Blanca in the open field cultivation were 50% and 45.4%, respectively, while those in the green house cultivation were significantly reduced to 1.5% and 1.9%, respectively, In the green house, the incidences of the disease in sprinkler watering cultivation were $14.5{\sim}16.5%$, while those in drip watering cultivation were only $1.5{\sim}2%$. Incidence of the disease was severe in the field where the lily was cultivated successively for 2 to 3 years. Isolation frequencies of B. elliptica from overwintered plant debrises such as leaves, stems, capsules, and bulbs were 43.3%, 46.7%, 60% and 0%, respectively, while those of B. cinerea were 10.3%, 0%, 3.3% and 0%, respectively, Incidence of leaf blight in the field where diseased plant debris was cleaned was 7.3%, while that in the field where diseased plant debris was not cleaned was 56.5%. Incidences of the disease in the field where coverages of soil surface with black vinyl, bark or rice straw were used were 6.6%, 8.2% and 11.3%, respectively, while that in the field where the coverage was not used was 21.3%.

• Research in Plant Disease
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• v.21 no.3
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• pp.243-249
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• 2015

Soybean frogeye leaf spot caused by the fungus Cercospora sojina Hara, has known to lead a severe reduction of crop yield. Since frogeye leaf spot on soybean has recently become a serious problem in Korea, the susceptibility of recent recommended cultivars against C. sojina had been tested. To standardize the disease severity of soybean, the optimum sporulation condition of C. sojina and the disease index were established in this study. Sporulation was maximized on the 10% V8 juice agar with 12 h light and 12 h dark at $25^{\circ}C$. Spore suspension ($10^5spores/ml$) was sprayed on the leaves of soybean (V6 stage), and the disease responses to each isolate were evaluated on 28 days after inoculation. As a result, Daepung, Shinpaldal2ho, Yeonpung and Cheonga showed the resistance reaction to 8, 7, 6, 6 isolates of C. sojina, respectively, whereas Cheongja, Hwangkeum, Taekwang, Daewon, Cheonsang and Sinhwa showed the susceptible reaction to 8 isolates of C. sojina. Breeding the resistant soybean cultivars against C. sojina requires a uniform resistance for screening technique. The disease index of frogeye leaf spot on soybean developed in this study can be effectively used for the accurate field assay to select the frogeye leaf spot resistant soybean.

• Korean journal of applied entomology
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• v.26 no.4 s.73
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• pp.269-272
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• 1987

Effects of dithane flowable and dithane M-45 on the control of opium poppy downy mildew were examined under field conditions. Application of these two fungicides significantly reduced the disease and increased latex yield, compared to other non-systemic fungicides.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.11 no.2 s.95
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• pp.86-92
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• 1990

최근 소득작물로 재배면적이 늘고있는 시설하우스의 채소재배는 시설의 대형화와 고정화로 인한 연작장해와 주년재배에 의한 포장환경의 오염, 시설내의 고온다습, 무리한 약제살포 등으로 노지재배에서는 별로 문제가 되지않던 병들이 하우스내의 온도보존을 위한 2중, 3중의 밀폐로인한 높은 습도 때문에 거의 모든 작물에서 잿빛곰팡이병, 균핵병등이 발생되고 있다. 또한 연작으로 인한 토양전염성 병균의 밀도가 높아져서 역병, 풋마름병, 덩굴마름병등이 발생될 뿐아니라 지력증진을 위한 미숙 유기물이나 생육촉진을 위한 제4종 복합비료, 생장조절제등의 남용으로 전에는 없었던 새로운 장해가 증가되고 있어 이에 대한 방제대책의 일환으로 주산단지를 이루고 있는 농가의 병해충 발생및 토양환경등을 중심으로 문제점을 분석하고 대책을 소개하기로 한다.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2001.05a
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• pp.139-139
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• 2001