• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.04a
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• pp.27.1-27
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• 1999

• Journal of Ginseng Research
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• v.4 no.2
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• pp.186-193
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• 1980

The causal organism of Phytophthora disease on Panax ginseng Meyer in Korea was isolated and identified as Phytophthora cactorum. It's pathogenicity, etiology, and possible control measures were investigated. Disease symptoms on various parts of ginseng plants were also described The fungus caused seedling and mature plant blight and root rot. Oospores were easily formed on potato dextrose agar and corn meal agar. Oospores, however, were not formed in the diseased root tissues but did in the in footed shoots such as leaves, petioles, and stems and in the inoculated berries.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.4
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• pp.223-231
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• 2002

A phosphate-solubilizing bacterium, Enterobacter intermedium 60-2G, was examined for plant growth-promotion and induction of systemic resistance using a model system of cucumber and scab disease, caused by Cladosporium cucumerinum. Compared with a nonbacterized control, treatment of cucumber with E. intermedium significantly reduced the severity of scab disease after challenge-inoculation with C. cucumerinum. Treatment of cucumber with E. intermedium also enhanced cucumber growth. The 60-2G strain showed a strong antimicrobial activity against several plant pathogenic fungi including Fusarium soysporum and Magnaporthe grisea. These results suggest the E. intermedium 60-2G is a promising candidate as a biological control agent displaying multiple beneficial properties to promote plant health.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.298-303
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• 1995

The biological control effect of Trichoderma harzianum on the Fusarium wilt of strawberry and several factors affecting on its efficacy were examined through pot experiments. T. harzianum grown on wheat barn, rice straw, rice hull, sawdust or barley straw was respectively incorporated into the pathogen-infected soil, and significantly suppressed the strawberry wilt caused by Fusarium oxysporum f. sp. fragariae. The wheat bran or rice straw culture of T. harzianum suppressed the disease incidence more effectively than other substrates for culture, decreasing it to 68% of the untreated control. The conidial suspension of T. harzianum alone or the suspension mixed with crab shell also effectively reduced the disease incidence. The control effectiveness of T. harzianum was high in acid soil (pH 3.5~5.5). In sandy loam soil, the disease incidences and population densities of the pathogen were decreased by the treatment of T. harzianum, while there was no significant effect of T. harzianum on the pathogen in loam soil.

• Research in Plant Disease
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• v.9 no.4
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• pp.224-228
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• 2003

Five commercial chemicals, Dimethomorph, Foseyl-Al, Oxadixyl + Mancozeb, Propamocarb hydrochloride, and Metalaxyl, were tested for control of tobacco black shank (Phytophthora nicotianae) and/or delaying buildup of the resistant population to Metalaxyl which has been used for control of the disease in Korean tobacco farms. Propamocarb hydrochloride seemed to have a cross-resistance to the Metalaxyl resistant isolates showing similar response with Metalaxyl in vitro. Meanwhile, Dimethomorph+Mancozeb and Oxadixyl+Mancozeb were selected to be the promising chemicals which are able to be alternative to Metalaxyl for the black shank control in accordance with in vitro and in field trial.

• Research in Plant Disease
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• v.7 no.1
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• pp.31-36
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• 2001

To establish an effective chemical control strategy against powder mildew of sweet pumpkin (Cucurbita maxima Duchesne) caused by Sphaertheca fuliginea, screening of effective fungicides and determination of their application times were conducted. Powdery mildew caused by S. fuliginea began to occur at about 80 days after transplanting and continuously increased until harvesting in Korea. Systemic fungicides, such as difenoconazole, triforine, bitertanol, and triflumizole, were effective for controlling powdery mildew, showing control efficacies of about 80-90%. When the fungicide triflumizole was applied 3 or 4 times from the beginning day of the disease at 10-day intervals, about 92.0% and 94.6% of disease control and yield increase of 7% and 9% were obtained, respectively. Therefore, the proper application of triflumizole for controlling powdery mildew of sweet pumpkin must be done more than 3 times.

• Mycobiology
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• v.42 no.4
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• pp.376-384
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• 2014

Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle.

• Korean journal of applied entomology
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• v.12 no.1
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• pp.33-39
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• 1973

The yield of rice is increased to amounts of fertilizer applied in paddy field but excessive application of fertilizer stimulates outbreaks of disease and insect pest. If, therefore, diseases and pests stimulated by excessive application of fertilizer would be effectively controlled, increaseed yield of rice would be possible. This experiment was conducted to determine the fertilizer application rate that would produce maximum yields when diseases and pests are controlled. 1. The fertilizer application rates and the incidence of leaf and apanicle blast were positively correlated at the $1\%$ level. 2, Without disease and pest control the maximum yield of hulled rice was 347-378kg/10a, which occurred at nitorgen application levels of 8.0-8.5 kg/10a. with effective control of diseases and pests the maximum yield of hulled was 453-462 kg/10a, which occurred at nitrogen application levels of 18.5-19.0 kg/10a. Yield increase at appropriate nitrogen levels by disease and pest control resulted in more than 100 kg/10a. 3. There was no significant yield difference between the NPK experimental plots with fixed PK levels and with varying PK levels. 4. The maximum effect of disease and pest .control as expressed biy yield index of hulled rice was $65\%$, the minimum effect was $30\%$, the average effects were $42-45\%$.

• Research in Plant Disease
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• v.26 no.1
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• pp.19-28
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• 2020

Jujube witches' broom (JWB) disease is a high-risk plant disease that occurred on and devastated jujube orchards throughout South Korea in the 1950s. Recently, as the jujube cultivation area has been significantly increased nationwide, we investigated the disease in jujube orchards in the Boeun region to obtain basic information for proactively evaluating the risk of JWB outbreaks from 2017 to 2019. A field trial was conducted to evaluate the effect of the trunk injection of Sungbocycline (a. i. oxytetracycline calcium alkyl trimethyl ammonium 17%, OTC). The incidence of JWB disease was very low in Boeun, but it was gradually increased mainly in the area and on the farms where it had occurred previously. The trunk injection with OTC was most effective in the early stages of growth. However, even though the trees were treated with OTC, disease symptoms appeared in other healthy branches in severely affected trees. When the tree was first injected with OTC in June, the control efficacy of second injection was higher one month after the first injection than five months. These results suggest that early diagnosis based on various symptoms and early control based on them can be very effective in preventing JWB disease in advance and increasing control efficacy.

• Plant Disease and Agriculture
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• v.1 no.1
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• pp.45-46
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• 1995

In recent years, there were considerably severe occurrences of TuMV(turnip mosaic virus) disease on radish and Chinese cabbage cultivated at alpine or sub-alpine regions, especially more severe on young Chinese cabbage sowed after late June. Started from 1991, those were very severe in 1992 and 1994, for the number of migrated aphids was increased enormously according to the weather condition of high temperature and low humidity then. This disease started at late June to early July, and continued to late August. It seemed that TuMV was transmitted easily and completely to the young chinese cabbages, but hardly and rarely the old. The regions over 1,000m of altitude had less possibility of disease-occurring, but there was severe occurrence on the second cropping of Chinese cabbage in a year. It is considered that more researches on control method of TuMV disease will be needed very urgently.