• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.283-289
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• 2009

Isolation frequency of resistant isolates of Phytophthora capsici to metalaxyl was reported to be 38.9% through the resistance monitoring for metalaxyl in P. capsici causing pepper Phytophthora blight. Metalaxyl was very effective to mycelium growth, while not to zoosporangium germination and zoospore release. $EC_{50}$ values of metalaxyl in the inhibition of mycelium growth were 0.204, 0.151, 0.379, and $0.215\;{\mu}g\;mL^{-1}$ against each isolate sensitive to the fungicide as P. capsici 06-119, 06-143, P08-7, and P08-31, respectively, whilst those were 5.242, 5.724, 6.621, and $5.377\;{\mu}g\;mL^{-1}$ in P. capsici 06-125, 06-155, P08-50, and P08-60. For the field fitness, several factors, which were mycelium growth, zoosporangium germination, zoospore release, virulence to pepper plants, and the zoosporangium and the oospore production, were investigated with 4 sensitive isolates and 4 resistant isolates. Between 2 groups differentiated by the sensitivity of metalaxyl, there was no significance in mycelium growth, zoosporangium germination, zoospore release, and virulence to pepper plants. However, the zoosporangium and the oospore production in each resistant isolate, which were related to survival of P. capsici in fields, were superior to those of sensitive isolates. Based on results of this study, it was suggested that the increase of the percentage of resistant isolates to metalaxyl resulted from the high capacities of the zoosporangium and the oospore production.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.4
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• pp.303-308
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• 1994

We have obtained following results by executing this experiment to define effects of organic substances applied and temperature on fungistatic effect which is regarded as basic factor of inhibition against hot-pepper blight affection : 1. Fungistatic effect of soil on Phytophthora capsici is enlarged by application of organic material such as rice straw rather than matured composts. Morever, it is confirmed that fungistatic efect is more eminent at the temperature of $15^{\circ}C$ and $5^{\circ}C$ than at $30^{\circ}C$, Degree of fungistatic effect of soil tends to decrease as the goe on from the moment of using organic substance generally, in soil applied as the goes on from the moment of using organic substance generally, in soil applied rice straw it is prove that fungistatic effect is maintained stably in a long term. 2. Effect of applicating organic substances and treating by temperature on production of zoosporangium of Phytophthra capsici is reviewed. In case that sterilized soil solution is added on cultured hypae of Phytophthra capsici, increase in the production of zoosporangium is found which is statistically significant(at degree of 1%), while decrease effect statistically significant is found in case of adding soil solution used for applying bark compost. However, defferences between treatments of temperature is not found. On the other hand, when nonsterilized soil solution is added, significant defference between types of organic substance is not found, while significant difference is found between treatments of temperature, therefore formation of zoosporangium is increased at the condition of $5^{\circ}C$ comparing to that of $30^{\circ}C$. 3. Putting above result of examination concerning to composition of soil microrganisms in each treated soil and to fungistatic effect of them, it seems that fungi and bacteria in soil is mostly related to fungistatic activity of soil.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.140-146
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• 2012

The commercial product "pyto-patch" prepared as nano sized silver particle less than 5 nm, has effective antifungal activity against Collectotrichum gloeosporioides, Botrytis cinerea, Sclerotinia sclerotiorum in vitro. As a fungal growth inhibiton mechanism, it can reduce spore germination rate and mycelial growth. As s promising fungicide, Phyto-patch can control anthracnose effectively. The spore of C. gloeosporioides dipped in 5 ppm phyto-patch dilute suppressed germination rate to 13.2%, and mycelial growth stopped for 15 days at 10 ppm. The spore postinoculated on 10 ppm phyto-path smeared PDA surface could not germinate for 3 days and prohibit pathogen infection effectively. In field test, the anthracnose development of 4 ppm phyto-patch treated plot was less than 7% after 21 days compaired to 40% of it in untreated plot. In heavy rainfall season, pepper anthracnose effectivly contrrolled by regular 10 ppm phytopatch spraying every 7 days. The diseased pepper fruit decreased to 5.8% compaired to 94.6% in untreated plot. During drying period, the diseased pepper fruit havested in phyto-patch treated plot was 24.2%, but pepper fruit havested in untreated plot destroyed to 100% within 3 days. The nano silver particle coated on multching textile prevented late blight of pepper effectively and disease occurance delayed about month.

• The Korean Journal of Mycology
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• v.19 no.3
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• pp.231-237
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• 1991

This study was conducted in order to find out biological control of sesame wilt and blight caused by Fusarium of oxysporum f. sp. vasinfectum and Phytophthora nicotianae var. parasitica by using Streptomyces spp. Two sesame pathogens, Fusarium oxysporum f. sp. vasinfectum and Phytophthora nicotianae var. parasitica were purely isolated from diseased sesame plants of the field. Streptomyces species were isolated from 72 soil samples collected from red pepper and sesame uplands in Chungbuk and selected as antagonists according to the results of dual culture. The selected Streptomyces isolates such as St-11 and St-20 were confirmed their antagonistic effect through mycelial inhibition zone and inhibitory effects on the mycelial growth of the pathogens by culture filterate of the antagonists. Inhibitory effects on the conidial germination of Fusarium oxysporum vasinfectum and Phytophthora nicotianae parasitica by the antagonists were also tested in addition to mycelial Iysis. The antagonists St-11 and St-20 showed inhibitory effect on growth of sesame seedlings after seeds soaked in the suspension. Effect of soil inoculation with antagonist St-11 showed 40 to 78 percent of control effect for two diseases in comparison with control under greenhouse.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.127-133
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• 1991

PI201232, a pepper line resistant to Phytophthora capsici Leonian, was crossed with PI2713222 and P1163192, resistant to Xanthomonas campestTis pv. vesicatoria (Doidge) Dye and inheritance of the resistance to each disease and genetic relationship between the two disease resistances was studied. Non-hypersensitive resistance to race 3 of X. c. pv. vesicatoria of PI271322 was inherited in a quantitative mode. Resitance to P. capsici of PI201232 was inherited in a mode close to two dominant alleles. Hypersensitive resistance to race 1 of X. c. pv. vesicatoria of PI271322 was inherited in a mode of single dominant allele. PI 163192 was consistently resistant to both race 1 and race 3 of X c. pv. vesicatoria and the resistance was inherited in a quantitative mode with high dominance effect. Resistance to X. c. pv. vesicatoria was inherited independently from resistance to P. capsici.

• Current Research on Agriculture and Life Sciences
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• v.20
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• pp.9-18
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• 2002

A total of 31 C. chinense lines selected from 2000 screening were tested again for resistance to P. capsid but resistance was not found in tile lines. A total of 26 selections from Korean land races tested 2001 spring were tested again for resistance to P. capsici, KC180, KC230, KC195 and KC194 showed moderate resistance to P. capsid. However, it was apparent on the basis of horticultural characteristics that KC180 and KC230 had been naturally crossed with AC2258 and CM334, respectively. CM334 and AC2248 seed lots that were increased in different years were taken out and tested for resistance to improve their genetic purity because the resistant genetic resources have been showing some off-types in tile population. Off-types began to be found in 1992 seed lots and tile proportion and degree of tile offs was increasing with time up to 2001. Plants true to the type in 1992 seed lots were selected and their inbred seeds were mass produced in a net cage in the greenhouse. AC2258 included in the experiment together was uniform. In 1995 seed lots of CM334, plants with resistance to P. capsici and low or no number of lateral branching at cotyledonary axil, although they were off from tile original CM334, were found and selection was applied to breed lines fixed in tile characters.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2018.06a
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• pp.117-118
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• 2018

• Korean Journal of Environmental Agriculture
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• v.20 no.3
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• pp.180-185
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• 2001

Control effects of phosphorous acid were investigated on Phytophthora blight of red pepper plants in greenhouse and field. In vitro test, the mycelial growth of Phytophthora capsici was inhibited by the phosphorous acid more than 97% at 1,000 ${\mu}g$ and 10,000 ${\mu}g$ a.i./mL in the liquid and solid culture, respectively. At concentration of 10 ${\mu}g$ a.i./mL of phosphorous acid, in the liquid culture the mycelial growth of P. capsici was inhibited 46.2%, however inhibited only 4.9% on the soild culture. Zoosporangial formation was also inhibited 89.1% by phosphorous acid at 100 ${\mu}g$ a.i./mL. Phosphorous acid affected more zoosporangial formation of P. capsici than its mycelial growth. At the concentrations of 10,000, 1,000 and 100 ${\mu}g$ a.i./mL of phosphorous acid, germination of zoosporangia was inhibited 100, 84.3 and 44.2%, respectively. Mycelial growth and zoosporangial formation of P. capsici were little affected at the concentration of 10 ${\mu}g$ a.i./mL of phosphorous acid. Cermination of zoosporangia was also little affected at this concentration, however growth of the germ tubes was inhibited and the abnormal mycelial growth was observed. Phosphorous acid suppressed the incidence of Phytophthora blight of red pepper plants up to $77.0{\sim}62.0%$, in greenhouse. Phosphorous acid suppressed the incidence of Phytophthora blight of red pepper plants up to 54.0% at the conventional culture in field. Treatments of phosphorous acid increased up to 113% in height, 135% in number of fruit, and 129% in weight of fruit.

• Korean Journal of Organic Agriculture
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• v.6 no.2
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• pp.117-125
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• 1998

For isolation of antagonistic fungi antagonistic to Phytophthora capsici, a total of 157 isolates of fungi were screened from soil. Among the 157 isolates further screened by the dual culture test on potato dextrose agar and V-8 juice agar, 16 isolates were tested to show their antagonistic activity against P. capsici and Fusarium oxysporum. Fungal cul-ture filtrates of screened 16 isolates were shown to inhibit germination of zoospoorangia of P. capsici entirely and conidia of F. oxysporum considerably. Antagonistic fungi were shown to suppress of P. capsici infection of red-pepper plants maintained in the green house. Four isolates. 27 J5, 37 J10, 36 J13 and 31 K10, with the reduced disease incidence 53.3∼60.0% were identified as Fusarium sp. (27 J5). Trichoderma sp. (37 J10, 36 J13) and Penicillium sp. (31 K10).

• 한국약용작물학회:학술대회논문집
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• 2008.11a
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• pp.350-351
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• 2008