• 식물병연구
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• 제9권4호
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• pp.213-216
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• 2003

2002년 봄, 순천시 비닐 하우스에서 육묘중인 차나무에 세균병이 발견되었다. 초기 병반은 신엽에 작은 수침상 병반이 나타났으며 갈색반점으로 변하였다. 이 병반은 점점 커졌으며, 중륵 또는 엽맥을 따라 신장하였으며 검은색으로 변하였고, 병든 잎은 쉽게 낙엽이 되었다. 병반으로부터 10균주를 분리하여 잎에 접종한 결과 자연 병반과 동일한 병징이 나타났다. 병원세균은 염색반응, 형태적 특성, colony 패턴, 생리적, 생화학적 반응에 따라 Pseudomonas syringae pv. theae로 동정되었다. 국내에서 이 균에 의한 차나무 세균병은 아직 보고되지 않았으므로 병명을 차나무 갈색마름병(brown blight)으로 명명할 것을 제안한다.

• 식물병연구
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• 제10권2호
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• pp.121-125
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• 2004

2000년도와 2001년도에 남부지방(구례, 별교, 영암)의 시설 내 오이재배지에서 갈색무늬병에 피해가 심하였다. 잎에서 전형적인 수침상 병반이 생기고 초기에 황색 halo를 지닌 갈색반점이 생긴 후 점차 불규칙하고 큰 병반으로 진전되어 때때로 낙엽을 유발하였다. 감염잎으로부터 분리한 병원균은 분생자경에 연쇄상 혹은 단일 분생포자를 형성하였고 분생포자는 거의 무색에서 올리브 갈색 내지는 갈색을 띠었으며 모양은 7-11개의 위격벽을 지닌 원통형,역곤봉형, 직립형, 만곡형 등이었다. 또한 분리 병원균의 ITS영역의 염기서열은 Corynespora cassciicola와 일치하였다. 형태적, ITS영역 분석을 기초로 분리된 병원균은 C. cassiicola로 동정하였다. 병원균의 생육은 3$0^{\circ}C$ Czapek Solution Agar 배지에서 가장 좋았으며, 발병환경 조사 결과 3$0^{\circ}C$에서 18시간 이상 습전시간이 유지될 때 발병이 높아, 고온과 식물의 긴 습전기간이 발병량의 증가를 가져오는 요인이었다. 또한 국내 품종들을 대상으로 오이갈색무늬병에 대한 감수성과 저항성 품종들을 선발하였다.

• The Plant Pathology Journal
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• 제34권2호
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• pp.121-125
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• 2018

Maize (Zea mays L.; 2N=20) is major staple food crop grown worldwide adapted to several biotic and abiotic stresses. Maydis leaf blight (MLB) and banded leaf and sheath blight (BLSB) are serious foliar fungal diseases may cause up to 40% and 100% grain yield loss, respectively. The present studies were undertaken to work out the efficacy of chemicals, botanicals and bioagents for the management of MLB and BLSB under field condition for two seasons Kharif 2014 and 2015. Five molecules (propiconazole 25 EC, hexaconazole 25 EC, carbendazim 50 WP, mancozeb 75 WP and carbedazim 12 WP + mancozeb 63 WP), two bioagents i.e. Trichoderma harzianum and T. viridae and three botanicals namely azadirachtin, sarpagandha and bel pathar were tested for their efficacy against MLB. Eight newer fungicides viz., difenconazole 250 SC, hexaconazole 5 EC, carbendazim 50WP, validamycin 3 L, tebuconazole 250 EC, trifloxystrobin 50 WG + tebuconazole 50 WG, azoxystrobin 250 EC and pencycuron 250 SC were evaluated against BLSB. Analysis revealed significant effects of propiconazole at 0.1%, carbendazim 12 WP + mancozeb 63 WP at 0.125% and sarpagandha leaves at 10% against MLB pathogen, whereas validamycin at 0.1% and trifloxystrobin 25 WG + tebuconazole 50 WG at 0.05% were found effective against BLSB. The slow rate of disease control virtually by the bioagents might have not shown instant effect on plant response to the yield enhancing components. The identified sources of management can be used further in strengthening the plant protection in maize against MLB and BLSB.

• 식물병연구
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• 제28권2호
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• pp.108-111
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• 2022

In December 2020, stem and leaf rot symptoms in small-fruited tomato (Solanum lycopersicum) plants were observed in a farmer's vinyl greenhouse located in Pyeongtaek, Gyeonggi Province, Korea. The incidence of diseased plants in the vinyl greenhouse was 2-6%. Seven single-spore isolates of Phoma sp. were obtained from the diseased stems and leaves. All the isolates were identified as Boeremia linicola based on the cultural, morphological and molecular characteristics. Two isolates of B. linicola were tested for pathogenicity on stems and leaves of small-fruited tomato and large-fruited tomato using artificial inoculation. All the tested isolates caused stem and leaf rot symptoms in the inoculated plants. The symptoms were similar to those observed in plants from the vinyl greenhouse investigated. This is the first report of B. linicola causing stem and leaf rot in tomato.

• 식물병연구
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• 제19권4호
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• pp.300-307
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• 2013

This study was conducted to determine the occurrence of leaf rot and leaf ring spot, caused by Rhizoctonia solani in Chinese cabbage under seedling nursery and cultivation greenhouses. Symptoms of leaf rot and leaf ring spot were found in three Chinese cabbage cultivars, Brassica campestris subsp. pekinensis, 'Ryeokgwang', 'Daetong', and 'CR mat'. In Hwacheon, the disease incidence was 73.8% in the seedling stage of the Chinese cabbage. In Icheon, the symptoms were observed on the upper leaves of the Chinese cabbage cultivar, 'Norangmini' with 20.5% of disease incidence. The symptoms appeared as primary lesions consisting of small, circular necrotic ring spots with gray color, 1.4-3.0 mm in diameter, accompanied by secondary rot lesions with large irregular borders of leaves. The color of mycelial mat of 20 isolates was dark brown and light brown. The average hyphal diameter of all the isolates was within 5.01-11.12 ${\mu}m$. Among the 20 strains isolated from Chinese cabbage, 16 isolates and four isolates anastomosed with the AG-1 (IB) and AG-1 (IC), respectively. Twenty isolates tested were only virulent on foliage parts of Chinese cabbage leaves but were avirulent on stem parts of the plants. Based on the mycological characteristics and pathogenicity test on host plants, the fungus was identified as Rhizoctonia solani.

• 식물병연구
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• 제22권3호
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• pp.133-144
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• 2016

Powdery mildew (Podosphaera xanthii) causes severe damage to pumpkin crops grown in open fields and plastic house. Initially, we used ten accessions of pumpkin species; Cucurbita pepo (3), C. maxima (2), C. moschata (2), and C. argyrosperma (3) to study the disease progress in different stages of seedling development. Commercial pumpkin varieties were used as susceptible host for inoculum management and young seedlings were inoculated by dusting powdery mildew spores on the cotyledons, 1-true-leaf and 2-true-leaf seedling stages. Based on initial study, we further evaluated 218 pumpkinaccessions for their resistance to powdery mildew in different seedling stages under plastic house. Area under disease progress curve (AUDPC) and relative AUDPC (rAUDPC) was higher in cotyledonary and 1-true-leaf than 2-true-leaf stage. Seedlings at cotyledons and 1-true-leaf seedling stage displayed more susceptibility to powdery mildew. Based on evaluation of 2-true-leaf stage, IT 110859 and IT 278459 from C. pepo and C. argyrosperma identified as resistant (<0.2). Of the 228 pumpkin accessions, 21 (9.2%) pumpkin accessions consisting of C. pepo (2), C. maxima (5), C. moschata (13), and C. argyrosperma (1) exhibited intermediate resistance (<0.4) to powdery mildew and these accessions are useful to growers for its rational management.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권2호
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• pp.163-169
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• 2003

Studies were conducted on the effect of pruning time, host age, conidial dispersal and weather parameters on the incidence and severity of mulberry leaf spot (Myrothecium roridum). The disease severity (%) increased with increase in shoot age irrespective of pruning date. Maximum disease severity was observed in plants pruned during first week of April and minimum disease severity in plants pruned during first week of March. Significant (P ＜ 0.01) influence of date of pruning, shoot age and their interaction was observed on severity of the disease. Apparent infection rate (r) was significantly higher during the plant growth period from day 48 to day 55. Average apparent yale was higher in plants pruned during first week of April and least in plants pruned during first week of July. The disease infection was negatively correlated to distance from the inoculum source. Leaf spot severity (%) was influenced by weather parameters. Multiple regression analysis revealed contribution of various combinations of weather parameters on the disease severity. Linear prediction model $(Y ＝ －81.803＋1.176x_2＋0.765x_3) with significant $R^2$ was developed for prediction of the disease under natural epiphytotic condition.

• The Plant Pathology Journal
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• 제16권5호
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• pp.257-263
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• 2000

Infection with rice blast fungus (Magnaporthe grisea) significantly reduced foliar net photosynthesis (A) of rice cultivars: Ilpoom, Hwasung, and Choochung in greenhouse experiments. By measuring the amount of diseased leaf area with a computer image analysis system, the relation between disease severity (DS) and net photosynthetic rate was curvilinearly correlated (r=0.679). Diseased leaves with 35% blast symptom can be predicted to have a 50% reduction of photosynthesis. The disease severity was linearly correlated (r=0.478) with total chlorophyll (chlorophyll a and chlorophyll b) per unit leaf area(TC). Light use efficiency was reduced by the fungal infection according to the light response curves. However, dark respiration (Rd) did not change after the fungal infection (p=0.526). Since the percent of reduction in photosynthesis greatly exceeded the percent of leaf area covered by blast lesions, loss of photosynthetic tissue on an area basis could not by itself account for the reduced photosynthesis. Quantitative photosynthetic reduction can be partially explained by decreasing TC, but cannot be explained by decreasing Rd. By photosynthesis (A)-internal CO$_2$ concentration (C$_i$ curve analysis, it was suggested that the fungal infection reduced ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, ribulose-1,5-bisphosphate (RuBP) regeneration, and inorganic phosphate regeneration. Thus, the reduction of photosynthesis by blast infection was associated with decreased TC and biochemical capacity, which comprises all carbon metabolism after CO$_2$ enters through the stomata.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권2호
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• pp.93-106
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• 2003

Soilborne diseases pose a serious problem for mulberry cultivation during nursery plantation and established gardens, which cause severe loss in revenue generation of mulberry growers as compared to foliar diseases. Various soilborne diseases affect mulberry. Among them, root knot and root rot affect the established plantation resulting in severe loss in leaf yield apart from deterioration in leaf quality, which is a pre-requisite in successful sericulture to get the good quality of cocoons. Besides, stem-canker, cutting rot, collar rot and die-back, affect the initial establishment and survivability of mulberry plantation in nursery. The problem is difficult to handle, due to the complex nature of the diseases and also involvement of various biotic and abiotic factors. This is compounded by the occurrence of disease complex (especially nematode ＋ soilborne pathogenic microbes) in established mulberry gardens, which facilitates quick spread of the disease and enhance the plant mortality, resulting substantial loss in leaf yield. Therefore, prevention and timely control measures need to be taken up to protect the mulberry plants from different soilborne plant pathogens. In this review article, symptomatology, epidemiology, disease cycle and control measures of soilborne diseases of mulberry are discussed.

• 식물병연구
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• 제18권3호
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• pp.255-258
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• 2012

2011년 9월, 충남 보령시와 부여군의 시설재배단지에서 재배중인 토마토의 잎에 Pseudocercospora fuligena에 의한 검은잎곰팡이병이 발생하였다. 이 병의 병징은 초기에는 잎에 연한 노란색의 불규칙한 점무늬가 발생하며, 점차 연한 갈색으로 변하고 잎 뒷면의 병반부위에 병원균의 분생포자를 다량으로 형성하면서 검은색의 그을음 병징을 나타내었다. 병든 토마토 식물체로부터 원인균을 분리하였고 현미경 검경을 통하여 형태적 특징을 분석한 결과 P. fuligena로 동정되었다. 온실조건에서 인공접종을 통하여 이 균의 병원성을 증명하였다. P. fuligena에 의한 토마토 검은잎곰팡이병의 발생은 우리나라에서 최초의 보고이다.