• The Plant Pathology Journal
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• 제32권6호
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• pp.519-527
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• 2016

Purple blotch, caused by Alternaria porri (Ellis) Cifferi, is a serious disease incurring heavy yield losses in the bulb and seed crop of onion and garlic worldwide. There is an immediate need for identification of effective resistance sources for use in host resistance breeding. A total of 43 Allium genotypes were screened for purple blotch resistance under field conditions. Allium cepa accession 'CBT-Ac77' and cultivar 'Arka Kalyan' were observed to be highly resistant. In vitro inoculation of a selected set of genotypes with A. porri, revealed that 7 days after inoculation was suitable to observe the disease severity. In vitro screening of 43 genotypes for resistance to A. porri revealed two resistant lines. An additional 14 genotypes showed consistent moderate resistance in the field as well as in vitro evaluations. Among the related Allium species, A. schoenoprasum and A. roylei showed the least disease index and can be used for interspecific hybridization with cultivated onion. Differential reaction analysis of three A. porri isolates (Apo-Chiplima, Apn-Nasik, Apg-Guntur) in 43 genotypes revealed significant variation among the evaluated Allium species (P = 0.001). All together, the present study suggest that, the newly identified resistance sources can be used as potential donors for ongoing purple blotch resistance breeding program in India.

• 식물병연구
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• 제21권4호
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• pp.261-267
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• 2015

본 연구에서는 경상북도 북부지역의 주요 사과 산지를 대상으로 재배 중에 발생하는 병해의 발병상황을 조사하고 병원균을 조사하였다. 경북 북부지역의 주요 사과 재배지에서 발병하는 주요 병은 탄저병, 겹무늬썩음병, 점무늬낙엽병, 갈색무늬병, 가지마름병이었다. 특히 2013년에 비해 2014년에는 갈색무늬병이 증가하였으며, 이는 10월의 강수량과 정의 상관관계가 인정된다. 점무늬낙엽병과 탄저병, 겹무늬썩음병도 모든 포장에서 발병되었다. 또한 P. syringae pv. syringae에 의한 가지마름병의 발병이 지역에 따라 10-20% 정도 발병하였다. 이러한 결과는 사과 재배에 있어 주요병해에 대한 중점 방제 대상 병해를 선정하여 관리하여야 하며, 또한 근래 문제되지 않았던 P. syringae pv. syringae에 의한 가지마름병에 대한 생태학적 연구 및 방제 연구가 수행하여야 할 것으로 판단된다.

• Mycobiology
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• 제35권1호
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• pp.39-43
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• 2007

The antifungal effect of pine needle extract prepared by a distinguishable extraction method and the dry distillation method, was examined. The effect of this extract itself was insignificant. The chemical components of pine needle extract were then investigated by gas chromatographic analysis, and four, chemical components, acetol, furfural, 5-methyl furfural, and terpine4-ol, were identified. The antifungal effects of those four chemical components against Alternaria mali (A. mali), an agent of Alternaria blotch of apple, were then examined. It was observed that the minimum inhibitory concentrations (MICs) were 6.25, 0.78, 0.78, and 12.5 (mg/ml) of acetol, furfural, 5-methyl furfural, and terpine-4-ol, respectively. MICs of furfural and 5-methyl furfural had the same order of magnitude as that of an antifungal agrochemical, chlorothalonil. Although furfural itself can not be completely substituted for an antifungal agrochemical, a partial mixture of furfural and antifungal agrochemical may be used as a substitute. The use of agrochemicals for the prevention of plant disease caused by pathogenic fungus such as A. mali could be partially reduced by the application of this mixture.

• 식물병연구
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• 제24권4호
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• pp.249-256
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• 2018

1992년부터 2010년까지 경북 군위를 비롯한 사과 주산지 8개 지역에서 사과의 잎에 발병하는 병의 발생상황을 조사하였다. 사과의 잎에 발병하는 주요 병은 붉은별무늬병, 잿빛곰팡이병, 점무늬낙엽병, 갈색무늬병이였다. 지난 19년간 사과 잎에 발병하는 병의 발생양상은 상당히 많이 변해왔는데, 1990년대 초반, 발생이 많아 문제가 되었던 붉은별무늬병, 검은별무늬병은 1990년대 후반 이후 발생이 감소하거나 발생하지 않았다. 잿빛곰팡이병은 일부 과원에 따라 발병이 관찰되었으며, 점무늬낙엽병과 갈색무늬병의 발병은 지속적으로 발병이 관찰되었다. 병해발생상황은 기상조건, 재배조건 및 방식, 약제 살포 체계 등 다양한 요인에 의해 변화한 것으로 판단된다. 이러한 병해들의 발생상황의 변화에 대한 조사는 장기적이고 지속적인 모니터링이 필요할 것으로 판단된다.

• 한국응용곤충학회지
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• 제24권3호
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• pp.135-139
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• 1985

Influence of temperature, relative humidity, spore washing and spore drying on conidial germination of Alternaria porri(Ell.) Cif. was studied. Maximum conidial germination occurred at 100% relative humidity prevailing for 6 hours or more at $25^{\circ}C$. Conidial germination decreased with increase in number of spore washings. Drying of conidia for more than half an hour caused significant decrease in germination. In all the experiments, conidial germinatio increased with increase in incubation period.

• 한국식물병리학회지
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• 제11권1호
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• pp.17-29
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• 1995

This study was conducted from 1991 to 1993 to develop a fungicidal spray program for the apples exportable to the United States of America, in which quarantine and pesticide residue in agricultural products are strictly regulated. In 1991, 2 spray schedules were applied to an orchard, in one of which the 7 fungicides registered for apple both in Korea and U.S. were used, and in the other of which the Bordeaux mixture for which the tolerance was exempted in U.S. was used 2 times along with those 7 fungicides. The apple white rot and fruit infection by Alternaria mali were not effectively controlled by the 7 fungicides alone; however, the control efficacy was raised by adding the Bordeaux mixture to the spray schedule. In 1992, 4 spray schedules were applied in which the kinds of fungicides and spray intervals were different one another. The results suggested that an effective spray program can be developed by adopting the Bordeaux mixture for 3 times or adopting the imminoctadine-triacetate which has not tolerance level in U.S. for same times in the vulnerable stage of apple white rot and alternaria blotch. In spite of the high efficacies against major apple diseases, the Bordeaux mixture could not be recommended to the apple growers due to the various defects such as restrictions in compatibility with insecticides and acaricides, troublesomeness in preparation and spray, especially the harmful effect on the finish of Fuji apples. In 1993, a spray program adopting 3 times of imminoctadine-triacetate during the growing season of apple was developed, which not only can effectively control the major apple diseases but also avoid the pesticide residue problems if it was sprayed 2 or 3 times after bagging. On the basis of the 3 years results, a basic fungicide spray program was formulated in which 1~3 times of imminoctadine-triacetate and 1~2 times of bitertanol were adopted in addition of the 7 common fungicides registered in both countries. In the results of application of the spray schedule to the actual farming in the 4 areas of Kyungpook Province in 1994, no noticeable defects were detected at the first year trial. However, this spray program will be continuously evaluated and modified to obtain better control efficacies against major apple diseases.

• The Plant Pathology Journal
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• 제22권4호
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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.

• 한국식물병리학회지
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• 제10권4호
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• pp.284-291
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• 1994

In order to establish an appropriate spray schedule to reduce the infection, 11 kinds of chemicals were tested for their properties on the inhibition of spore germination at the surface of apple fruits and the duration of the inhibitory effect after spray of each chemical was examined from late June to early September with basically 10 day intervals. Actual control efficacy of each chemical by the 8 successive spray and the patterns of waterborne spore dispersals during that periods were also examined. Combining those results with the meteorological observation data, actual control efficacy of each chemical in the given periods could be estimated. It was revealed that folpet, Brodeaux mixture, mancozeb, oxine copper and imminoctadine-triacetate could be used at any time during the possible infection periods. Captan and dithianon could also be used except the rainy season due to the short duration of inhibitory efficacy against spore germination under heavy rain. However, the usefulness of propineb, benomyl and chlorothalonil against the apple white rot could not be demonstrated in this experiment. Thiram, even though has not been used for apple white rot, can also be used before or after the rainy season to control not only white rot but also alternaria blotch.