• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.190-190
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• 2020

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.191-191
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• 2020

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.192-192
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• 2020

• Research in Plant Disease
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• v.17 no.3
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• pp.402-404
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• 2011

The Sclerotium blight was found on Phalaenopsis spp. at Dong-du-cheon city, and Hwa-seong city, Gyenggido, Korea in September 2009. The symptom included yellowing on lower leaves and wilt of a whole plant. Severely infected plants were blighted and died eventually. White mycelial mats appeared on the surface of basal stem and bulbs and the sclerotia were formed on stems, roots, and sphagnum moss. The sclerotia were spherical, 1-3 mm and white to brown. The optimum temperature for the growth and sclerotia formation was $25-30^{\circ}C$ on PDA. On the pathogenicity test, the first symptom appeared 5 days after inoculation and developed to severe stem rot and blight. On the basis of mycological characteristics and pathogenicity, the causal fungus was identified as Sclerotium rolfsii. This is the first report on the sclerotium blight on Phalaenopsis spp. caused by Sclerotium rolfsii in Korea.

• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.298-302
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• 2011

Bacterial wilt, caused by Ralstonia, solanacearum, is a very destructive disease to tomato plants (Solanum lycopersicum) in Korea. This study was undertaken to find out the growth inhibitory effect bactericides on bacterial wilt pathogen of streptomycin, oxytetracyclin streptomycin sulfate WP and significantly suppressed the growth of bacterial wilt pathogen. Copper hydroxide WP showed control value of 62.5%. Therefore, it is concluded that the bactericide used in this study showed strong inhibitory effect to tomato bacterial wilt and they can be recommend to control the disease. And also, Copper hydroxide WP may be effective for control of bacterial wilt of tomato in conventional culture, farming without agricultural and organic farming.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.544-549
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• 2018

Thrips populations were monitored in field-cultivated pepper at Gochang, Jeonbuk province, Cheongyang, Chungnam province, and Goesan, Chungbuk province during the field growing seasons of 2017 to 2018, respectively. We classified and quantified thrips population in each plot and year. Most of the monitored thrips were composed of three species: Frankliniella intonsa, F. occidentalis, and Thrips tabaci, respectively. F. intonsa was the dominant species in all the monitoring season. The density of thrips was increased from late June in each field and year with the highest density being recorded in mid-July. Based on the results, management strategy of thrips in red peppers should be evaluated from early June with monitoring and appropriate controls.

• Research in Plant Disease
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• v.25 no.2
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• pp.94-97
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• 2019

In February 2019, a damping-off disease occurred at the seedling stage of paprika in a commercial nursery located in Cheorwon, Korea. A species of Fusarium was isolated from the diseased plant and it was identified as Fusarium oxysporum based on morphological characteristics and nucleotide sequence data of translation elongation factor $1-{\alpha}$ and the largest subunit of RNA polymerase. The isolate obtained was revealed to be pathogenic to the host plant through pathogenicity tests, and the reisolation of the pathogen confirmed Koch's postulates. This is the first report of damping-off caused by Fusarium oxysporum on paprika in Korea.

• Research in Plant Disease
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• v.27 no.1
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• pp.17-23
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• 2021

Cucumber mosaic virus (CMV), the most prevalent virus in chili pepper (Capsicum annuum L.), negatively affects chili pepper production in South Korea. In this study, foliar spraying with β-glucans obtained from the mycelial walls of the yeast-like fungus Aureobasidium pullulans inhibited CMV infection of chili pepper if applied before virus inoculation. At three concentrations, β-glucans from A. pullulans significantly ameliorated CMV symptoms in treated chili pepper; the effect was greater in plants treated with 0.01% β-glucans than 0.005% or 0.001% β-glucans. Double antibody sandwich enzyme-linked immunosorbent assay showed that these β-glucans treatments resulted in 1.7- to 10-fold reductions in CMV accumulation in the treated chili pepper. The glucans did not act directly on the virus and did not interfere with virus disassembly or replication. Foliar spraying with 0.01% β-glucans from A. pullulans at 24 hr intervals for 3 days significantly increased plant height, the total number of fruit, and the fresh weight of chili pepper fruit. However, the stem diameter of chili pepper treated with β-glucans did not increase significantly. These results indicate that foliar spraying with β-glucans from A. pullulans acts an antiviral agent against CMV infection and stimulates chili pepper growth.

• The Plant Pathology Journal
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• v.39 no.6
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• pp.600-613
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• 2023

Fusarium oxysporum is the main pathogen causing Fusarium basal rot in onion (Allium cepa L.), which incurs significant yield losses before and after harvest. Among management strategies, biological control is an environmentally safe and sustainable alternative to chemical control. In this study, we isolated and screened bacteria for antifungal activity against the basal rot pathogen F. oxysporum. Isolates 23-045, 23-046, 23-052, 23-055, and 23-056 significantly inhibited F. oxysporum mycelial growth and conidial germination. Isolates 23-045, 23-046, 23-052, and 23-056 suppressed the development of Fusarium basal rot in both onion seedlings and bulbs in pot and spray inoculation assays. Isolate 23-055 was effective in onion seedlings but exhibited weak inhibitory effect on onion bulbs. Based on analyses of the 16S rRNA and rpoB gene sequences together with morphological analysis, isolates 23-045, 23-046, 23-052, and 23-055 were identified as Bacillus thuringiensis, and isolate 23-056 as Bacillus toyonensis. All five bacterial isolates exhibited cellulolytic, proteolytic, and phosphate-solubilizing activity, which may contribute to their antagonistic activity against onion basal rot disease. Taken together B. thuringiensis 23-045, 23-046, 23-052, and 23-055 and B. toyonensis 23-056 have potential for the biological control of Fusarium basal rot in onion.

• Korean Journal of Medicinal Crop Science
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• v.17 no.5
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• pp.346-351
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• 2009

To study the optimal cultivation for paddy soil, growth characteristics and ginsenoside content was investigated by both of poor drainage class (PDC) and imperfect drainage class (IDC) in three-year-old ginseng of varieties, Cheonpoong (CP), Yeonpoong (YP), Hwangsookjong (HS), and Jakyeongjong (JK). Root yield of IDC was higher than that of PDC by 3.6 times because stem length, leaf area, and chlorophyll contents were increased, while discolored leaf ratio was decreased. Root yield of HS in PDC was highest among four varieties because chlorophyll contents, leaf area, and survived plant ratio were relatively high. Root yield of CP in IDC was highest among four varieties because of high leaf area and survived plant ratio, and low discolored leaf ratio. Ratio of rusty-colored root showed significant difference by varieties, which was the highest in HS and the lowest in CP among four varieties irrespective of drainage classes. Total ginsenoside contents showed significant difference by drainage classes, which were high in IDC of good growth and low in PDC of poor growth. Total ginsenoside contents were high in JK and CP, while low in HS and YP both of drainage classes.