• Journal of Ginseng Research
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• v.42 no.2
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• pp.175-182
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• 2018

Background: The impact of fungicide azoxystrobin, applied as foliar spray, on the physiological and biochemical indices and ginsenoside contents of ginseng was studied in ginseng (Panax ginseng Mey. cv. "Ermaya") under natural environmental conditions. Different concentrations of 25% azoxystrobin SC (150 g a.i./ha and 225 g a.i./ha) on ginseng plants were sprayed three times, and the changes in physiological and biochemical indices and ginsenoside contents of ginseng leaves were tested. Methods: Physiological and biochemical indices were measured using a spectrophotometer (Shimadzu UV-2450). Every index was determined three times per replication. Extracts of ginsenosides were analyzed by HPLC (Shimadzu LC20-AB) utilizing a GL-Wondasil $C_{18}$ column. Results: Chlorophyll and soluble protein contents were significantly (p = 0.05) increased compared with the control by the application of azoxystrobin. Additionally, activities of superoxide dismutase, catalase, ascorbate peroxidase, peroxidase, and ginsenoside contents in azoxystrobin-treated plants were improved, and malondialdehyde content and $O_2^-$ contents were reduced effectively. Azoxystrobin treatments to ginseng plants at all growth stages suggested that the azoxystrobin-induced delay of senescence was due to an enhanced antioxidant enzyme activity protecting the plants from harmful active oxygen species. When the dose of azoxystrobin was 225 g a.i./ha, the effect was more significant. Conclusion: This work suggested that azoxystrobin played a role in delaying senescence by changing physiological and biochemical indices and improving ginsenoside contents in ginseng leaves.

• Korean Journal of Environmental Agriculture
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• v.23 no.3
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• pp.178-184
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• 2004

Tolclofosmethyl (TCFM) is heavily and annually applied to the turf soils of most golf courses in Gyeongju to control the fungi known to cause the disease brown patch. The soil samples used for the experiment was collected three weeks after the annual application at the end of May in the year 2002. The preliminary results obtained from this study demonstrated that the repeated field annual applications of TCFM to the turf soils of a golf course located in Gyeongju city in the southern area of Korea showed the enhanced degradation of the parent compound TCFM, especially in the surface ($0{\sim}15\;cm$) soil rather than the shallow subsurface ($15{\sim}30\;cm$) and deep subsurface ($30{\sim}45\;cm$) soils, compared to the corresponding surface ($0{\sim}15\;cm$) and shallow and deep subsurface ($15{\sim}30\;cm$ and $30{\sim}45\;cm$) soils of the untreated plot. It appears that microorganisms in the soil may be involved in the enhanced degradation of TCFM.

• Research in Plant Disease
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• v.12 no.3
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• pp.249-253
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• 2006

Several fungicides such as polyoxine B, fludioxonil, tebuconazole, tebuconazole+dichlofluanid, and fenbuconazole were sprayed once a week on roses in greenhouse. Botrytis infection on stalks was reduced by 71-89% after regular fungicide spray. The reduction of conidial inoculum by these treatments is also observed. The rose petal infections were controlled significantly by these fungicides only 2 days after the application. The development of gray mold on rose flowers harvested just after spray of fludioxonil, tebuconazole and tebuconazole+dichlofluanid were reduced compared to untreated control. This beneficial effect was also shown in flowers artificially inoculated with B. cinerea conidia after harvest. Post-harvest treatments by spraying cut flowers with the fungicides such as iprodine plus thiram, tebuconazole+dichlofluanid and polyoxin D reduced disease incidence by 50-55%.

• Research in Plant Disease
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• v.15 no.3
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• pp.248-253
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• 2009

Chitosan has an antifungal activity and is widely used for control of various plant disease and plants growth in the field in Korea. Disease control efficacy of two preparations (SH-1, SH-2) of mixtures of high and low (chitooligosaccharide) molecular weight chitosan compounds against tomato leaf mold caused by Fulvia fulva was investigated under plastic greenhouse conditions. Both SH-1 and SH-2 formulations displayed potent disease control activity in two experiments. The protective activity of both preparations was comparable to synthetic thiophanate-M. The persistence activity of the formulations was sustained until 21 days after application. Effective concentration of the chtosan compounds for disease control was 1,200 mg a.i./L. In pot tests, chitosan preparations, at a concentration of 600 mg a.i./L, promoted plants growth. These results indicate that the chitosan preparations have a potential as an eco-friendly natural fungicide for the control of tomato leaf mold and plant growth regulator.

• Korean journal of applied entomology
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• v.15 no.2 s.27
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• pp.57-60
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• 1976

Experiments were carried out to determine the effectiveness of a new systemic fungicide EL-291 (5-Methyl-1, 2,4-triazolo (3,4-b) benzothiazole) for the control of rice blast disease in greenhouse and paddy field. The efficiency of EL-291 was much greater when applied before inoculation than when applied after inoculation. Kasugamin and Benlate were most effective as eradicants. For control of leaf blast, effectiveness of EL-291 was not significantly different than either Kasugamin or Benlate. However, EL-291 was considered more economical and reliable than either Kasugamin or Benlate. EL-291 required only a single foliar application or a transplant root soak, whereas two applications of the other fungicides were required. EL-191 was also more effective against panicle blast when applied only once, compared with two applications of Kasugamin or Benlate. The highest riceyields were obtained in plots treated with EL-29l.

• Korean journal of applied entomology
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• v.21 no.4 s.53
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• pp.207-210
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• 1982

The studies were carried out to examine susceptibility or resistance of junipers as an inform ediate host of pear rust, to select effective fungicides to pear and juniper rust, and to determine their application time. The telia were formed abundanty on Juniperus chinensis var. kaizuka, moderately on J. chinensis, J. chinensis var. sargentii and J. virginiana, but little on J. chinensis var. globosa and J. utilis. The telia from the junipers were pathogenic to pear. Spraying juniper host with the fungicide Actidione in the 1st and End parts of April greaty inhibited swelling of telia as well as germination of teliospores. The two or three applications of Bayleton at the end of April to May 10 were remarkably effective for the control of pear rust. Fungicide sprays just before rain were more effective than those after rain.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.533-542
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• 2021

Chitosan has been considered an environmental-friendly polymer. However, its use in agriculture has not been extended yet due to its relatively low solubility in water. N-Methylene phosphonic chitosan (NMPC) is a water-soluble derivative prepared by adding a phosphonic group to chitosan. This study demonstrates that NMPC has a fungicidal effect on the phytopathogenic fungus Fusarium solani f. sp. eumartii (F. eumartii) judged by the inhibition of F. eumartti mycelial growth and spore germination. NMPC affected fungal membrane permeability, reactive oxygen species production, and cell death. Also, this chitosan-derivative exerted antifungal effects against two other phytopathogens, Botrytis cinerea, and Phytophthora infestans. NMPC did not affect tomato cell viability at the same doses applied to these phytopathogens to exert fungicide action. In addition to water solubility, the selective biological cytotoxicity of NMPC adds value in its application as an antimicrobial agent in agriculture.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.1-20
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• 2023

In the past, rice bakanae was considered an endemic disease that did not cause significant losses in Korea; however, the disease has recently become a serious threat due to climate change, changes in farming practices, and the emergence of fungicide-resistant strains. Since the bakanae outbreak in 2006, its incidence has gradually decreased due to the application of effective control measures such as hot water immersion methods and seed disinfectants. However, in 2013, a marked increase in bakanae incidence was observed, causing problems for rice farmers. Therefore, in this review, we present the potential risks from climate change based on an epidemiological understanding of the pathogen, host plant, and environment, which are the key elements influencing the incidence of bakanae. In addition, disease management options to reduce the disease pressure of bakanae below the economic threshold level are investigated, with a specific focus on resistant varieties, as well as chemical, biological, cultural, and physical control methods. Lastly, as more effective countermeasures to bakanae, we propose an integrated disease management option that combines different control methods, including advanced imaging technologies such as remote sensing. In this review, we revisit and examine bakanae, a traditional seed-borne fungal disease that has not gained considerable attention in the agricultural history of Korea. Based on the understanding of the present significance and anticipated risks of the disease, the findings of this study are expected to provide useful information for the establishment of an effective response strategy to bakanae in the era of climate change.

• Korean Journal of Environmental Agriculture
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• v.23 no.3
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• pp.142-147
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• 2004

Dissipation pattern of tebuconazole was evaluated by establishing application methods of the fungicide, paper-bagging of grape during growth and washing of grape after harvest. Application times increased from three to five resulted in high levels of residues in grape. Tebuconazole in grapes was present in different residual patterns with periods after final treatment ranging from 7 to 25 days. Significant differences in the residual patterns were also found when tebuconazole was treated during three different application periods, possibly due to meteorological condition and/or grape growth during each period. At the range from 2.5 g to 7.5 g of grape granules, residues were higher in small-sized grape than in big-sized grape and were mostly distributed on the peel of the grapes. Paper-bagging was a critical factor for reducing the fungicide residue on the peel. flesh of bagged and no-bagged grape had very low level of residues, 0.01 mg/kg and 0.05 mg/kg, respectively. Residues on grape was effectively eliminated with the washing methods suggested, a consecutive sinking-washing system Using of detergent solution during washing showed maximum residue reduction from grape. The washing methods showed effective action on the removal of lower content providing complete elimination, or almost, of the residues.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.366-373
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• 2011

This study was conducted to identify the residue patterns of fungicide boscalid in ginseng cultivated for 4 or 6 years treated by various spraying methods. The pesticide was sprayed separately on ginseng according to safe use guideline, and the field was divided into three groups and they were traditional, soil and vinyl mulching applications. The maximum residue amounts of boscalid were 0.76 mg/kg in traditional application group, 0.69 mg/kg in soil application group, 0.62 mg/kg in vinyl mulching application group in the whole part of 4 years old ginseng, respectively. These residue levels in ginseng exceeded the maximum residue limit established by Korea Food & Drug Administration, which is 0.3 mg/kg.