• 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 $1,000{\mu}g/mL$.

• Research in Plant Disease
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• v.28 no.3
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• pp.122-131
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• 2022

Colletotrichum acutatum s. lat. 20JDS8 sensitive and 20CDJ6 resistant to pylaclostrobin were used to investigate the cross-resistance with fungicides belonging to the strobilurins and the characteristics of fungicidal controlling activities with different mechanisms against the isolate resistant to the fungicide. The resistant isolate of 20CDJ6 also showed the resistance to azoxystrobin, trifloxystrobin, and kresoxim-methyl, suggesting that there is a cross-resistance relationship. All fungicides with different action mechanisms inhibited mycelial growth of both susceptible and resistant isolates of C. acutatum s. lat., but their disease control effects in fruits were different according to the fungicides. The disease control effect of isopyrazam against 20JDS8 and 20CDJ6 was very low, and fluazinam showed a control effect of 91.9% and 88.1% against 20JDS8 and 20CDJ6 only when it was treated before inoculation by spraying spore suspensions on pepper fruits without wounds. Tebuconazole and prochloraz effectively inhibited not only the mycelial growth of 20JDS8 and 20CDJ6 on potato dextrose agar medium, but also disease incidence in red pepper fruits. As a result of this study, C. acutatum s. lat. 20CDJ6 resistant to pyraclostrobin showed cross-resistance with other strobilurin fungicides. In addition, we think that fluazinam, tebuconazole, and prochloraz can be recommended as alternative fungicides for the control of red-pepper pyranthracnose pathogens resistant pyraclostrobin. However, fluazinam can be effective only if it is treated protectively before the occurrence of the disease.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.397-403
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• 2008

Nikkomycins are a group of peptidyl nucleoside antibiotics with potent fungicidal, insecticidal, and acaricidal activities. sanN was cloned from the partial genomic library of Streptomyces ansochromogenes 7100. Gene disruption and complementation analysis demonstrated that sanN is essential for nikkomycin biosynthesis in S. ansochromogenes. Primer extension assay indicated that sanN is transcribed from two promoters (sanN-P1 and sanN-P2), and sanN-P2 plays a more important role in nikkomycin biosynthesis. Purified recombinant SanN acts as a dehydrogenase to convert benzoate-CoA to benzaldehyde in a random-order mechanism in vitro, with respective $K_{cat}/K_m$$ values of $3.8mM^{-1}s^{-1}\;and\;12.0mM^{-1}s^{-1}$ toward benzoate-CoA and NADH, suggesting that SanN catalyzes the formation of picolinaldehyde during biosynthesis of nikkomycin X and Z components in the wild-type stain. These data would facilitate us to understand the biosynthetic pathway of nikkomycins and to consider the combinatorial synthesis of novel antibiotic derivatives.

• Mycobiology
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• v.40 no.1
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• pp.53-58
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• 2012

This research is concerned with the fungicidal properties of nano-size silver colloidal solution used as an agent for antifungal treatment of various plant pathogens. We used WA-CV-WA13B, WA-AT-WB13R, and WA-PR-WB13R silver nanoparticles (AgNPs) at concentrations of 10, 25, 50, and 100 ppm. Eighteen different plant pathogenic fungi were treated with these AgNPs on potato dextrose agar (PDA), malt extract agar, and corn meal agar plates. We calculated fungal inhibition in order to evaluate the antifungal efficacy of silver nanoparticles against pathogens. The results indicated that AgNPs possess antifungal properties against these plant pathogens at various levels. Treatment with WA-CV-WB13R AgNPs resulted in maximum inhibition of most fungi. Results also showed that the most significant inhibition of plant pathogenic fungi was observed on PDA and 100 ppm of AgNPs.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.109.2-109
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• 2003

A basic spray program for apple in which fungicides are scheduled to spray at 15-day interval from petal fall to late August was formulated on the properties of several selected fungicides. In order to improve it, experimental plots, completely randomized block with 3 replications, were prepared in an orchard of 15 years old Fuji cultivar, and the spray programs in which only one chemical in the basic spray program was substituted with others were applied to each plot. It was revealed that only single substitution of the fungicide in the basic spray program makes a great differences in the control of white rot and bitter rot, and that the control property of the fungicides against the two diseases was quite variable even by the time of application. A simila! ! r trial was conducted in 2002 with a new basic spray program that was formulated with fungicides that have shown best control in each spraying time in the previous trial, similar results were obtained. Applying this method, the usefulness of certain fungicide in the spray program for apple could be properly assessed. Anthracnose of Robinia pseudo-acacia L. caused by Collectotrichum spp.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.1
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• pp.28-38
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• 1993

For the purpose of evaluating the cleansing efficiency against Candida albicans detected frequently in patients with denture stomatitis, two denture cleansers with or without enzymes were studied under the same conditions. The results were as fellows: 1. Enzyme-contain denture cleanser was showed more Candida albicans lytic ability than non-enzyme-contained denture cleanser. 2. It was observed that Candida albicans lytic activity in further diluted manufacturerers' recommended concentration was decreased. 3. In fungicidal test, the enzyme-contained denture cleanser sterilized Candida albicans, and the non-enzyme-contained denture cleanser did not sterilize Candida albicans. 4. Sterilizing time of Candid albicans was needed for at least 60 minutes in enzyme-contained denture cleanser solution which was diluted with manufacturerers' recommended concentrations., and was needed for more times with further diluted manufacturerers' recommended concentrations. 5. In vitro growth test of Candida albicans on acrylic resin surface, the only enzyme-contained denture cleanser inhibited growth of Candida albicans, and it was observed that inhibiton ability of growth of Candida albicans on arrylic resin surface was decreased in further diluted manufacturerers' recommended concentrations.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.439-446
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• 2008

A fungicidal spray program for effective control of three major apple diseases in Korea (white rot, bitter rot, and Marssonina blotch) was developed. This was based on our previous studies showing that application of ergosterol biosynthesis inhibitors (EBIs) in early or mid-August can eradicate white rot infection in fruit and that some protective fungicides show after-infection activity against white rot. The basic spray program focused on control of white rot, the main target disease, and the fungicides were sprayed at 15-day intervals from petal fall to late August using fungicides that show after-infection and EBI activity. The basic spray program was modified over 4 successive years to improve control efficacy against bitter rot and Marssonina blotch, which sometimes cause as much damage as white rot. Modifications to the regime were made every year by replacing one fungicide in the basic program at a specific spraying time. Substitution of only one fungicide in the spray program, even early in the growing season, greatly influenced the final disease incidence at harvest. Applying this principle, a moderately efficient spray program for cv. Fuji that increased the spray interval from 10 to 15 days and thus reduced the number of sprays required per crop season was developed.

• Journal of Microbiology and Biotechnology
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• v.30 no.6
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• pp.878-884
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• 2020

Penicillium digitatum and P. italicum are the two important postharvest pathogens in citrus, causing about 90% of the total loss of citrus fruit during storage and transportation. Natural fungicides such as essential oils have been widely used instead of chemical fungicides for preventing and controlling postharvest diseases. In this research, p-anisaldehyde exhibited a strong inhibitory effect on P. digitatum and P. italicum, with the minimum inhibitory concentration and minimum fungicidal concentration values of both being 2.00 μl/ml. Additionally, p-anisaldehyde visibly inhibited both the green mold and blue mold development of citrus fruits inoculated with P. digitatum and P. italicum. The mycelia morphologies of these pathogens were greatly altered, and the membrane permeability and cell wall integrity of mycelia were severely disrupted under p-anisaldehyde treatment. These results suggest that the antifungal activity of p-anisaldehyde against P. digitatum and P. italicum can be attributed to the disruption of the cell wall integrity.

• Mycobiology
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• v.30 no.4
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• pp.233-239
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• 2002

The main aim of this study is to evaluate the efficiency of two biologically active compounds(Strom and F-760) in control of wheat root rot disease and its causal organisms. Fusarium graminearum, F. oxysporum, F. solani and Bipolaris sorokiniana were used as target organisms. In vitro, the two compounds showed fungicidal effect on all investigated pathogens resulted in suppression of radial growth and mycelial dry weight of them. Under greenhouse conditions, treatment of wheat grains with either Strom or F-760 before cultivation significantly reduced the percent of disease distribution as well as the mean disease rating of plants in both seedling and flowering stages. Fresh and dry weights of plants as well as water maintenance capacity were increased as the result of applying these compounds as seed dressing. Also data showed that the membrane stability of plants was injured as a result of infection with all investigated organisms, while this injury was alleviated when F-760 and Strom were applied. The $K^+$ efflux and the leakage of UV absorbing metabolites was stimulated with fungal infection. However, F-760 and Storm treatment partially retarded the stimulatory effect on leakage of $K^+$ and UV-absorbing metabolites of fungal infected plants. On the other side, the fungal infection had inhibitory effects on pigment fractions(chlorophyll a, b, and carotenoids) biosynthesis in wheat leaves. This retarding effect was partially or completely alleviated as the grains were treated with the applied compounds.

• Journal of the Korea Furniture Society
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• v.19 no.5
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• pp.358-364
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• 2008

Wood-inorganic material composite (WIC) was prepared by impregnating wood with copper sulfate ($CuSO_4\;5H_2O$) solution and by immersed wood in sodium carbonate($Na_2CO_3$) solution in order to introduce insoluble copper compounds {copper carbonate hydroxide, $CuCO_3\;Cu(OH)_2$} into the wood to give fungicidal effects in treated-wood. The weight percent gains (WPGs) of treated wood reached maximum value by impregnation of 20% copper sulfate solution and immersion in about 15% sodium carbonate solution for 24 hrs. Inorganic substances were present mainly in the lumina and cross-field pitting of tracheides. These substances were proved to be the insoluble copper carbonate hydroxide against water by the energy dispersive X-ray analyzer in conjunction with a scanning electron microscope (SEM-EDXA). The treated specimens showed high preservative effectiveness because the weight losses were hardly occurred by the fungi degradation test.