• Korean Journal of Soil Science and Fertilizer
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• v.39 no.5
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• pp.280-284
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• 2006

The toxic effects of 14 commercially available fungicides on the earthworm, Eisenia fetida (Savigny), were evaluated using surface sprayed soil, immersion and contact filter tests. At recommended dose, the earthworm mortality is 4% on mancozeb, carbendazim, propineb and captan in the surface sprayed soil test, 4% on mancozeb, 6% on propineb and 10% on captan in the immersion test, and no effect on all used chemicals in contact filter test.

• The Korean Journal of Mycology
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• v.34 no.1
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• pp.22-28
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• 2006

Attempts were made to control Diatrype stigma occurred on the bed-log of Shiitake using wood vinegar, Pinus koraiensis extract, Piper nigrum extract, and fungicides. Mycelial growth of D. stigma was inhibited completely at 35,000 ppm and no ascospore germinated at 25,000 ppm wood vinegar. Inhibition rates of Pinus koraiensis extract (200 ppm), and Piper nigrum extract (1,000 ppm) to ascospore germination were 98.9% and 95.9%, respectively. In fungicide selection, minimum inhibitory concentration (MIC) of benomyl, carbendazim, and thiabendazole ranged $0{\sim}0.4\;{\mu}g\;a.i/m{\ell}$. Difenoconazole at $0.08\;{\mu}g\;a.i/m{\ell}$ inhibited 98.9% of ascospore germination. Inhibition efficacy of fungicides was not highly variable among the low-, middle-, and high-temperature type strains of shiitake. Benomyl, carbendazim, thiabendazole and thiophanate-methyl could not suppress the mycelial growth of Shiitake. Tebuconazole at $0.4\;{\mu}g\;a.i/m{\ell}$ suppressed 80% of the mycelial growth and it was the highest inhibition rate among the fungicides. In field trials, wood vinegar, Pinus koraiensis extract, Piper nigrum extract, and fungicides were sprayed on the bed-logs before or after D. stigma produced pycnidia. Wood vinegar at 150,000 ppm concentration, showed control effect of 72.7% in the treatment before pycnidiospore formation. On the other hand, 70,000 ppm wood vinegar and 1,000 ppm of thiophanate-methyl showed control effects of 58.1% and 52.3% in the treatment after pycnidiospore formation.

• Research in Plant Disease
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• v.9 no.3
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• pp.131-136
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• 2003

The effects of temperature, duration of wetness period, and fungicides on the spore germination, appressorium formation, acervulus formation and lesion development by Colletotrichum spp., cause of soybean anthracnose, and their pathogenicity were assessed in controlled environment. C. gloeosporioides was highly pathogenic on inoculated soybean seeds as high as C. truncatum, whereas remarkably low on the soybean leaves. Spore germination, appressorium formation and mycelial growth of C. gloeosporioides were best at $25^{\circ}C$, but C. truncatum was best at $30^{\circ}C$. It has also done at $15^{\circ}C$, even though it was much retarded. C. truncatum showed high sensitivity to the fungicides, fluazinam and benomyl, meanshile C. gloeosporioides showed to fluazinam and triflumizole. At least 8 hrs. of wetness period was requird for the pathogen to develop lesions at $30^{\circ}C$. When the wetness period was 32 hrs. lesion size of was larger at $25^{\circ}C$ than $30^{\circ}C$, however it was traceable at $20^{\circ}C$. Different sensitivity of Colletotrichum spp. to fungicides suggests that proper fungicide is required to effective control of soybean anthracnose ingected multiply with Colletotrichum spp.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.61-67
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• 2001

Five hundred sixteen isolates of Botrytis elliptica were isolated from infected leaves of Lilium longiflorum from Kangwon alpine areas in Korea during tile seasons from 1998 to 2000 and resistance of these isolates against some fungicides were examined. The isolation frequency of phenotypes resistant to benomyl, procymidone, and diethofencarb were 90.1, 32.4, and 40.9%, respectively. The isolates were divided into six phenotypic groups; RSS, RRS, SSR, SRR, RSR and RRR, representing sensitive (S) or resistant (R) to benzimidazole, dicarboximide, and N-phenylcarbamate fungicides in order. The percentage of six phenotypes were 40.7, 8.5, 7.2, 2.7, 19.8, and 21.1%, respectively. The RSS phenotype was the most frequently isolated, and tile SRR consisted of the extremely minor populations. In comparison studies on tile overwintering ability of each phenotype in relation to the others, the most frequently isolated RSS and SSR had the higher fitness ability than the less frequently isolated RSR, SRR, and RRR. Recently, population increase of tile RSR and RRR phenotypes may have resulted from the increased applications of the mixture of carbendazim and diethofencarb to control benzimidazole-resistant B. elliptica since 1998. The results of this study indicate that careful application of the fungicides is necessary to achieve effective control of leaf blight on lily in Korea.

• Applied Biological Chemistry
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• v.42 no.4
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• pp.356-360
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• 1999

Growth-inhibitory effects of citrus oils and agricultural fungicides, which were on the market, on several molds isolated from putrefied citrus fruits were investigated. When fungicidal activities of 11 kinds of synthetic agrochemicals against 6 species of molds, Alternaria alternata, Rhizopus sp., Botrytis cinerea, Monilia candida, Penicillium italicum and Penicillium digitatum, were investigated, agrochemicals containing mancozeb or fluazinam as an effective component had the broadest fungicidal spectrum. Agrochemicals containing iprodione, benomyl, azoxystrobin or thiophanate were less effective on the molds and those containing conazole derivative were intermediately effective. Resistance of the molds to the agrochemicals were species- and agrochemical-dependent. Among those molds tested, Penicillium italicum and Alternaria alternata showed relatively higher level of survival in the presence of synthetic fungicides. On the other hand, when the molds were exposed to citrus oils by direct contact, no cell could survive regardless of the species. The fungicidal activity of citrus oils was also confirmed by paper disk method and microscopic observation. These results suggested that citrus oils had broad killing activity against molds. Therefore, it would be necessary to design method for the application of citrus oils in order to improve post-harvest storage of citrus fruits.

• The Korean Journal of Pesticide Science
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• v.5 no.2
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• pp.51-57
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• 2001

Controlling effect of several surfactants on barley powdery mildew (pathogen : Erysiphae graminis) and those influence on fungicidal activity by tank-mixing with commercialized fungicides were investigated in greenhouse test with barley seedlings. While protective activity of PNPP showed 90% at $1,000{\mu}g/mL$, that of LN 13.0 91.2%, tile best among 8 surfactants used in curative test. With $500{\mu}g/mL$, LN 13.0 showed 4% of disease percentage on the first leaf of narley continuously 4 days after the curative application. Excent for PNPP, the other surfactants, including NP 13.0, LN 13.0, and PAS, showed good inhibitory activity against spore germination in water agar medium amended with those surfactants. PAS, which showed very poor effect against barley powdery mildew in greenhouse test, strongly inhibited spore germination. Fungicide of triadimefon and triforine showed no controlling activity against Erysiphae graminis in narley seedlings, but they highly controlled powdery mildew in case of addition with $500{\mu}g/mL$ of LN 13.0 and Tween 20. SP 13.0, NP 13.0, LN 13.0 and DBC showed severe phytotoxicity in first leaf of barley seedlings, but Tween 20, SLIS, PAS, and PNPP not at $1,000{\mu}g/mL$.

• Journal of Life Science
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• v.30 no.2
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• pp.178-185
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• 2020

Rice bakanae is a typical seed-borne and seed-transmitted disease caused by infection by Fusarium fujikuroi. Seed disinfection using chemical fungicides (such as benomyl and prochloraz) is most effective in controlling the disease, but the emergence of fungicide-resistant strains has recently been increasing. Slightly acidic hypochlorous acid water (SAHW) is a safe and environmentally friendly disinfectant that has a potent and broad spectrum of antimicrobial activity against viruses, bacteria, and fungi. In this study, we aimed to investigate the effectiveness of SAHW against F. fujikuroi strains, including chemical fungicide-resistant strains, as an alternative to conventional chemical fungicides in the management of bakanae disease. SAHW showed strong but similar levels of antifungal activity among the F. fujikuroi strains with a minimum inhibitory concentration (MIC₉₀) of 5±2.5 ppm of free available chlorine (FAC). In addition, F. fujikuroi cells lost viability completely within 5 min of SAHW treatment due to the lethal damage to cell integrity. When the rice seeds infected by F. fujikuroi were treated with SAHW containing 20±10 ppm of FAC for 12 hr, the efficiencies of seed disinfection and disease control were 95-98% and 90.1-92.6%, respectively. Altogether, our data suggest that SAHW is an effective compound for controlling rice bakanae disease.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1103-1108
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• 2016

Yam anthracnose caused by Colletotrichum gloeosporioides (C.g) is the most devastating disease of yam (Dioscorea sp.). In the present study, we evaluated the culture filtrate extract (CFE) of azalomycin-producing Streptomyces malaysiensis strain MJM1968 for the control of yam anthracnose. MJM1968 showed strong antagonistic activity against C.g in vitro. Furthermore, the MJM1968 CFE was tested for inhibition of spore germination in C.g, where it completely inhibited spore germination at a concentration of 50 μg/ml. To assess the in planta efficacy of the CFE and spores of MJM1968 against C.g, a detached leaf bioassay was conducted, which showed both the treatments suppressed anthracnose development on detached yam leaves. Furthermore, a greenhouse study was conducted to evaluate the CFE from MJM1968 as a fungicide for the control of yam anthracnose. The CFE non-treated plants showed a disease severity of >92% after 90 days of artificial inoculation with C.g, whereas the disease severity of CFE-treated and benomyl-treated yam plants was reduced to 26% and 15%, respectively, after 90 days. Analysis of the yam tubers from the CFE-treated and non-treated groups showed that tubers from the CFE-treated plants were larger than that of non-treated plants, which produced abnormal smaller tubers typical of anthracnose. This study demonstrated the utility of the CFE from S. malaysiensis strain MJM1968 as a biofungicide for the control of yam anthracnose.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.148-155
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• 2000

The typhoon and flooding injury in rice were investigated both the region of downpour at the middle of August and the region of typhoon 'Yanni' at the late of September, 1998 in Kyongbuk provincial of Korea. More than 10% of rice stem were buried by soil inundation, the heading was delayed and the high node tiller was brought out. Yield components were deteriorated and yield was reduced. As the clay in the muddy water was attached on grains of rice, the yield was greatly reduced by reason of low grain filling ratio and polished rice ratio. The injury of muddy water was less at yellow ripening stage than at early ripening stage. On the other hand, the muddy water injury was reduced by the fungicide 'Benomyl' and 'Daconil' treatments. The degree of lodging according to varieties and ripening stages was not made a great difference, while the lodging was mainly occurred in the early transplanting time. In a week after lodging, viviparous spikes were occurred in almost all varieties, the degree of viviparity was shown highly in order of early maturing, middle maturing and late maturing varieties in the field as well as in laboratory test. The viviperous spikes were greatly occurred in the lodging toward hill space within row than row space because the more grains were touched on the ground.

• Mycobiology
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• v.47 no.3
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• pp.308-318
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• 2019

Bio-sulfur can be produced in the process of desulfurization from a landfill and collected by some microorganism such as Thiobacillus sp. as a sulfur element. In order to investigate practical use of bio-sulfur as an agent for controlling plant disease, in vitro antifungal activity of bio-sulfur was tested against Colletotrichum orbiculare known to cause cucumber anthracnose. Efficacy of bio-sulfur for suppressing anthracnose disease was also evaluated in vivo using cucumber leaves. Mycelial growth of C. orbiculare on medium containing bio-sulfur was inhibited. Disease severity of cucumber leaves pre-treated with bio-sulfur was significantly decreased compared to that of untreated ones. To illustrate how bio-sulfur could suppress anthracnose disease, structures of cucumber leaves infected with C. orbiculare were observed under a fluorescent microscope and a scanning electron microscope (SEM). Cucumber leaves pre-treated with bio-sulfur showed a low rate of appressorium formation whereas untreated ones showed abundant appressoria. Shrunk fungal hyphae were mostly observed on bio-sulfur-pretreated leaves by SEM. Similar results were observed on leaves pre-treated with a commercial fungicide Benomyl(R). These results suggest that inhibition of appressorium formation of C. orbiculare by bio-sulfur may contribute to its suppression of cucumber anthracnose.