• Title/Summary/Keyword: Leaf Diseases

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Efficacy of Fungicides for the Control of Leaf Spots on Eriobotrya japonica and Photinia glabra (비파나무 및 홍가시나무 점무늬병의 살균제 방제효과)

  • Seo, Sang-Tae;Shin, Chang-Hoon;Ji, Kwon-Hyeok;Park, So-Young
    • Research in Plant Disease
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    • v.17 no.3
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    • pp.410-412
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    • 2011
  • Since the late 2000s, a serious Entomosporium leaf spot disease, caused by Entomosporium mespili, has been found frequently on leaves of Eriobotrya japonica and Photinia glabra at a nursery station in Goheung and Jeju, respectively. Studies were conducted to select fungicides that would effectively control Entomosporium leaf spot. Among the three fungicides tested, weekly foliar applications of propiconazole and chlorothalonil effectively reduced disease severity on E. japonica and P. glabra showing control value of 64.1% and 87.6%, respectively. Weekly treatments of thiopanate methyl were less effective. Propiconazole controlled the disease, but, it was phytotoxic to P. glabra.

Leaf Spot of safflower (Carthamus thinctorius) caused by Alternaria carthami and A. alternata (Alternaria carthami와 A. alternata에 의한 잇꽃 잎점무늬병)

  • Park, Kyeng-Seuk;Lee, Soon-Gu
    • Research in Plant Disease
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    • v.9 no.3
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    • pp.159-161
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    • 2003
  • Leaf spot diseases were found on safflower (Carthamus thinctorius) leaf in several fields located in Euisong-Gun, Gyengbuk province in Korea. The infected leaf rate of the diseases in surveyed area were different each years from 2001 to 2003 such as about 5%, 10%, and 30%, repectively. The typicla symptoms of diseases appeared first as small, light brown spots on leaves. And then spot turn dark brown and magnified. And yellow decoloration zone appeared surrounding dark brown spots. Mycological characteristics of Alternaria carthami, isolated from safflower mature leaf spot were dark gray colonies, conidiophores simple erect, septated, 40~80 ${\mu}m$ length; conidia solitary, straight, body size fo without beak length 40~100${\mu}m$, 10~15${\mu}m$ thick, Number of transverse septa 4~10 and longitudinal septa 4~7 ; beak with 2~4 septa, 30~65${\mu}m$ length. And A. alternata, isolated from old leaf were gray~dark gray colonies, conidiophores simple or branched, 20~110 ${\mu}m$ length; conidia long chaines, short conical or cylindrical beak, 2~6 transverse septa and several longitudinal septa, body size of without beak length 30~60 ${\mu}m$, 10~20 ${\mu}m$ thick ; beak length 5~35 ${\mu}m$. These are the first report on the leaf spot of safflower caused by Alternaria carthami, A alternata in Korea.

Diseases and Weeds Occurrence and Control in Organic and Conventional Rice Paddy Field (유기 및 관행벼 재배지 병해와 잡초 발생 및 방제에 관한 연구)

  • Lee Sang-Guei;Lee Yong-Hoan;Kim Ji-Soo;Lee Byong-Mo;Kim Mi-Ja;Shin Jae-Hoon;Kim Han-Myeng;Choi Doo-Hoi
    • Korean Journal of Organic Agriculture
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    • v.13 no.3
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    • pp.291-300
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    • 2005
  • Diseases were surveyed in 5 Rice paddy field areas of Organic paddy field and conventional paddy field. The 3 major diseases, rice leaf blast, bacterial leaf blight and sheath blight in rice were surveyed at duck raising, rice bran and conventional rice paddy field. They were serious in duck raising paddy field, rice bran paddy field more than conventional paddy field. The Ilpum variety were infected seriously more than Chucheong. At the effectivity test of the environment-friendly substance for the rice-seed sterilization, 1000-times diluted brown-rice vinegar showed controlling effect against Bakanae disease, and germination rate also was good. There was no Weeds Control efficacy by cultivating of hairy vetch in rice paddy field. However, extract of hairy vetch Leaf and root repressed the germinating of lettuce seed.

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Survey on the Occurrence of Abiotic Diseases on Kiwifruit in Korea

  • Koh, Young-Jin;Lim, Myoung-Taek;Jeong, In-Ho;Kim, Gyoung-Hee;Han, Tae-Woong;Cha, Ju-Hoon;Shin, Jong-Sup
    • The Plant Pathology Journal
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    • v.23 no.4
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    • pp.308-313
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    • 2007
  • A survey of the occurrence of abiotic diseases on kiwifruit (Actinidia deliciosa) trees was conducted at sixty-two kiwifruit orchards in twenty-one locations of Jeonnam and Jeju Provinces in Korea during the 2007 growing season. Various kinds of abiotic diseases were detected on the kiwifruit trees. Malformed fruits caused by incomplete pollination were commonly observed among the normally growing fruits on almost all of the kiwifruit trees examined. Fruits imbued with wire rust, fruits scratched or girdled by the wire and fruits injured by sunscald occurred in all of the examined orchards. Abnormal growth of girdled branches by the fence wire, dead trees killed by excessive soil moisture due to poor draining and leaf chlorosis by nutrient deficiencies were found in some orchards. Leaf spotting by herbicide and leaf scorch or blight by excessively high temperature were observed. Leaf blight on young shoots by late frost and bark split on trunks by freeze occurred in several open-field orchards. Flooding and strong wind damages by attack of typhoon 'Nari' were also found during the survey period. Cup-shaped leaves frequently occurred on young shoots in early spring and the incidence of the syndrome tends to increase annually in recent years, which are not etiologically defined until now.

Effect of Leaf Mustard (Brassica juncea) on Lipid Metabolism of Rat with Chroethanol Administration (갓(Brassica juncea) 첨가식이가 만성적인 알콜 투여시 흰쥐의 지방대사에 미치는 영향)

  • 차연수;정복미
    • Korean Journal of Human Ecology
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    • v.1 no.1
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    • pp.94-102
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    • 1998
  • This study was undertaken to investigate the effects of mustard leaf diet on the lipid metabolism under chronic alcohol administration. Sprague-Dawley male rats were fed either AIN-76 diet(control), control with ethanol, AIN-76 diet plus 5% mustard leaf(mustard leaf), or mustard leaf with ethanol lot 30 days. On the 21st day, all of the rats were given an oral dose of ethanol and blood-ethanol concentration were monitored for the next 5 hours. Lipid and enzyme determinations in serum and liver were carried out after 30 days. The results obtained were summarized as following: 1) Supplementing 5% of mustard leaf did not recover the body weight loss due to chronic alcohol administration. 2) There were no significant differences in blood ethanol concentrations among the experimental groups. 3) Mustard leaf diet decreased the plasma total cholesterol, triglyceride levels increased due to the chronic alcohol administration, but not HDL-, LDL-cholesterol, and liver lipids. 4) Mustard leaf diet decreased ${\gamma}$ -GTP level increased by chronic alcohol administration. Overall, these data suggest that mustard lear can have a recovery function, which was not via ethanol metabolism on the symptoms of alcohol related diseases.(Korean J Human Ecology 1(1) : 94~102, 1998)

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Incidence of Alternaria Species Associated with Watermelon Leaf Blight in Korea

  • Kwon, Oh-Kyu;Jeong, A-Ram;Jeong, Yong-Jik;Kim, Young-Ah;Shim, Jaekyung;Jang, Yoon Jeong;Lee, Gung Pyo;Park, Chang-Jin
    • The Plant Pathology Journal
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    • v.37 no.4
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    • pp.329-338
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    • 2021
  • Alternaria leaf blight is one of the most common diseases in watermelon worldwide. In Korea, however, the Alternaria species causing the watermelon leaf blight have not been investigated thoroughly. A total of 16 Alternaria isolates was recovered from diseased watermelon leaves with leaf blight symptoms, which were collected from 14 fields in Korea. Analysis of internal transcribed spacer (ITS) region, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and RNA polymerase II second largest subunit (RPB2) were not competent to differentiate the Alternaria isolates. On the contrary, analysis of amplicon size of the histone H3 (HIS3) gene successfully differentiated the isolates into three Alternaria subgroups, and further sequence analysis of them identified three Alternaria spp. Alternaria tenuissima, A. gaisen, and A. alternata. Representative Alternaria isolates from three species induced dark brown leaf spot lesions on detached watermelon leaves, indicating that A. tenuissima, A. gaisen, and A. alternata are all causal agents of Alternaria leaf blight. Our results indicate that the Alternaria species associated watermelon leaf blight in Korea is more complex than reported previously. This is the first report regarding the population structure of Alternaria species causing watermelon leaf blight in Korea.

The Ameliorative Effects of Korean Bean-Leaves on Inflammation and Liver Injury in Obese Rat Model

  • Jin, Byung-Moon;Choi, Seok-Cheol;Lee, Hye-Sook;Jung, Sang-Bong;Hyun, Kyung-Yae
    • Biomedical Science Letters
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    • v.19 no.3
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    • pp.195-205
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    • 2013
  • Obesity may cause metabolic syndrome and adult diseases. This study was undertaken to investigate the ameliorative or useful effects of beanleaves on inflammation and liver damage in obese rat models. Rats were divided into three groups: a control group (normal diet, n=6), a fat diet group (45%-fat diet, n=7), and a bean leaf group (45%-fat+Korean bean leaves diet, n=7). Body weights in the bean leaf group were lower than those of the fat group (P<0.05). Serum tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and prostaglandin $E_2$ ($PGE_2$) concentrations were lower in both the control and bean leaf groups than in the fat group (P<0.001). TNF-${\alpha}$ concentrations in the bean leaf group were slightly higher than in the control group but statistically significant (P<0.05). The bean leaf group histologically exhibited lower fatty degeneration, spotty necrosis, and leukocyte infiltrations in hepatic tissues than those of the fat group. In the homogenized liver tissues, the cyclooxygenase-2 (COX-2) gene was only expressed in the fat group. The gene expression levels of hepatic TNF-${\alpha}$, inducible nitric-oxide synthase, peroxiome proliferator-activated receptor-${\alpha}$ (PPAR-${\alpha}$), poly (ADP-ribose) polymerase (PARP), and transforming growth factor-${\beta}1$ (TGF-${\beta}1$) were weaker in the bean leaf group than in the fat group. These results suggest that adding bean-leaves to the diet may ameliorate obesity-induced systemic inflammation and liver damage and that bean leaves may be a useful food for preventing obesity and thereby metabolic syndrome and adult diseases.

Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides

  • Lai, Yi-Ru;Lin, Pei-Yu;Chen, Chao-Ying;Huang, Chien-Jui
    • The Plant Pathology Journal
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    • v.32 no.5
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    • pp.481-488
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    • 2016
  • Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates.

Survey on the Occurrence of Apple Diseases in Korea from 1992 to 2000

  • Lee, Dong-Hyuk;Lee, Soon-Won;Choi, Kyung-Hee;Kim, Dong-A;Uhm, Jae-Youl
    • The Plant Pathology Journal
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    • v.22 no.4
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    • pp.375-380
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    • 2006
  • In the survey from 1992 to 2000, twenty-eight parasitic diseases were observed in major apple producing areas in Korea. The predominant apple diseases were white rot(Botryosphaeria dothidea), Marssonina blotch(Marssonina mali), Valsa canker(Valsa ceratosperma), Alternaria leaf spot(Alternaria mali), and bitter rot(Collectotrichum gloeosporioides and C. acutatum). Apple scab that reappeared in 1990 after disappearance for 15 years was disappeared again since 1997. A viroid disease(caused by apple scar skin viroid) was newly found in this survey. The five diseases, fire blight(Erwinia amylovora), black rot(Botryosphaeria obtusa), scab(Cladosporium carpophilum), Monochaetia twig blight(Monochaetia sp.), and brown leaf spot(Hendersonia mali), which had once described in 1928 but no further reports on their occurrence, were not found in this survey. However, blossom blight(Monilinia mali), brown rot(Monilinia fructigena), and pink rot(Trichothecium roseum), which did not occur on apple after mid 1970s, were found in this survey.