• Korean journal of applied entomology
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• v.22 no.1 s.54
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• pp.7-14
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• 1983

Septoria brown spot closed by Septoria glycines is one of the most serious fungal diseases in soybean. Average yield reduction of 3 varieties for two years was $16.1\%$ by the septoria brown spot inoculation and $9.0\%$ by the natural infection as compared to fungicide-sprayed plots. Number of pods per plant and seed weight were significantly reduced while plant height, number of branches and number of nodes per plant were not affected. Yield reduction was positively correlated to the septoria brown spot severity in all varieties examined. Correlation coefficient $(r=0.38^*)$ between yield reduction and area under the disease progress curve was higher than that (r=0.156) between yield reduction and Van der Plank's apparent infection rate. Potential effect of the septoria brown spot on the soybean yield reduction estimated with the area under the disease progress curve was expressed by the equation of Y=4.38+0.05X $(r=0.0696^*,\;df=25)$.

• Korean Journal Plant Pathology
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• v.3 no.4
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• pp.285-290
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• 1987

Septoria brown spot caused by Septoria glycines Hemmi is one of the serious fungal diseases in soybean. Since little has been known about the disease progress in the field, the present study was conducted to determine the factors affecting the disease progress in the soybean plant. Disease severity and pattern of the progress of the Septoria brown spot were different with varieties. Susceptibility of soybean plants increased with increase of plant age and leaf maturity in order from the primary leaf to the newly expanded leaf. It seemed to be related with conidial germination on the leaves. Germination and germtube elongation were more inhibited by the diffusates obtained from upper leaves than those from lower leaves and they were higher in a susceptible variety than in a moderately resistant one.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.1
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• pp.47-53
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• 1980

Of 1, 428 entries examined to locate gene sources resistant to Septoria brown spot from the Korean native soybean collection, most lines were evaluated as highly susceptible, showing numerous leaf spots with surrounding yellowing tissue, while 136 lines of the entries showed the leaf spots without the yellowing. However, leaf defoliation was so much higher in inoculated soybean plants than those of uninoculated, regardless of leaf yellowing that resistance to Septoria brown spot could not be characterized by the lesion type. Various yield composing characters were negatively correlated to the leaf defoliation, suggesting that early defoliation incited by Septoria brown spot might result in significant yield reduction in soybean.

• Mycobiology
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• v.48 no.6
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• pp.495-500
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• 2020

Leaf spot on lemon balm is frequently observed in Korea, causing considerable damage to crops. In 2014 and 2015, the occurrence of leaf spot was observed in several production greenhouses at Suwon, Gongju, and Namwon in Korea. Symptoms on lower leaves initially developed as small, distinct, discolored lesions, which enlarged progressively turning into dark brown, angular spots surrounded by purplish-brown margins. Based on the morphological characteristics and sequence analysis of actin (ACT), translation elongation factor 1-alpha (EF-1α), internal transcribed spacer (ITS), 28S nrDNA (LSU), and RNA polymerase II second largest subunit (RPB2), the fungus associated with the lemon balm leaf spot was determined as Septoria melissae. To the best of our knowledge, this is the first report of lemon balm leaf spot caused by S. melissae in Asia as well as in Korea.

• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.103-106
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• 1985

The present study was carried out to determine appropriate growth stage for evaluating resistance to septoria brown spot in field and to search resistance sources from soybean germ plasm. Disease severity expressed by log $\frac{x}{1-x}$ was different with soybean genotypes and vertical progress of the disease was related to the diseased leaf area. Correlation between diseased leaf area and the area under septoria brown spot disease progress curve (AUBC) was highest at full blooming stage, indicating a reasonable stage for measuring the disease severity to evaluate resistance in field. There was no lines highly resistant to the disease among 1,428 native soybean lines tested.

• Korean Journal Plant Pathology
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• v.14 no.1
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• pp.52-61
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• 1998

This paper is the fifth report about the fungal diseases of economic resource plants observed newly in Korea. It contains short descriptions on symptoms, occurrence conditions, pathogens, and some phytopathological notes for each of 10 fungal plant diseases. They are identified as leaf spot of Adenophora triphylla var. japonica by Septoria lengyelii, leaf spot of Calystegia soldanella by S. convolvuli, leaf spot of Campanula punctata by S. campanulae, leaf spot of Codonopsis lanceolata by S. codonopsidis, leaf spot of Geum japonicum by s. gei, black spot of Oenanthe javanica by s. oenanthes, leaf spot of Oenothera odorata by S. oenotherae, angular leaf spot of Rehmannia glutinosa by S. digitalis, brown spot of Rubus crataegifolius by s. rubi, and leaf spot of Viola verecunda by S. violae-palustris, respectively.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.676-681
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• 1998

Disease incidence of Codonopsis lanceolata was surveyed at the major cultivating fields in Chonbuk province in 1996 to 1997. The main diseases of Codonopsis lanceolata were ovserved as leaf spot caused by Septoria codonopsis, anthracnose by Glomerella cingulata, brown leaf spot by Cercospora sp., rust by Coleosporium koreanum, powdery mildew by Erysiphe sp., Fusarium wilt caused by Fusarium oxyporum, and white root rot by Sclerotium rolfsii. Anthracnose, leaf spot and brown leaf spot occurred severely on leaves from early July to late August. They were caused early fallen leaves. Fusarium wilt and white root rot occurred severely on stem and below the soil line in late August. They resulted in withering to death or chlorosis and fallen of leaves. Disease incidence of Codonopsis lanceolata was also substantially different in occurrence with a method of cultivation in late growth stage. Fusarium wilt and white root rot were more severe with a method of no support cultivation than those with a method of support cultivation with a stick. Fusarium wilt occurred 48.8% in a method of no support cultivation but 3.1% in a method of support cultivation with a stick. And white root rot occurred 18.9% in a method of no support cultivation but 0.3% in a method of no support cultivation with a stick. Thus, it proved that soil-borne diseases could be controlled support cultivation with a stick.

• Korean journal of applied entomology
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• v.23 no.1 s.58
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• pp.61-67
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• 1984

Conidial germination of Septoria glycines Hemmi, brown spot fungus of soybean, was studied by slide germination test. Poor conidial germination of S. glycines was observed on sterile distilled water, but potato dextrose agar(PDA) and distilled water floated with soybean leaf disc furnished a satisfactory medium for conidial germination. Exogenous supply of carbon source was essential for conidial germination, while phosphorous and potassium were not evident as that for carbon. Soluble starch was the most suitable as a carbon source for conidial germination and followed by D-glucose, D-galactose and lactose in that order. Maximum germination was attained in the $5\times10^{-2}mol$. concentration of glucose. Germination was decreased with increment of conidial concentration and was almost completely suppressed in the density of 10,000 conidia per $mm^2$. It suggested existing a self-inhibitor(s). Non-washed conidia germinated more than washed conidia and this was obvious when the conidia density was over $2\times10^3$ conidia per $mm^2$ on the dry agar block.