• The Korean Journal of Pesticide Science
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• v.7 no.3
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• pp.216-222
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• 2003

In order to develop effective control methods for Bakanae disease caused by Gibberella fujikuroi (Saito) Ito during rearing of rice seedlings, we investigated the disease resistance of 15 rice varieties to G. fujikuroi and control effect of six seed disinfectants, and tried to improve the using methods of the seed disinfectants. Disease resistance was tested by investigating the disease incidence on each rice cultivar grown in rice seedling box infested with or not infested with G. fujikuroi at 30 days after sowing seeds and 20 days after heading date. The results showed that Hwayongbyeo, Dongjinbyeo, Hwoanbyeo, Nonghobyeo, Nampyeongbyeo, and Hwojinbyeo were resistant G. fujikuroi, meanwhile Keulubyeo, Sobibyeo, Odaebyeo, Junambyeo, Samchonebyeo, Sangjubyeo, and Hwabongbyeo were susceptible. Three seed disinfectants, prochloraz, fludioxonil, and carproamid + thiram + fludioxonil controlled Bakanae disease of rice very well, while bonomyl + thiram, thiophanate-methyl + thiram and thiophanate-methyl + triflumizole did not suppress the disease enough. Water temperature was turned to be an important factor for controlling the disease by treating seed disinfectants. Prochloraz showed 61% control value on the disease at $10^{\circ}C$, but it showed above 95% control value at the range of $30-35^{\circ}C$. It was confirmed that the control effect of seed disinfectants increased with increasing water temperature. Meanwhile soaking period of rice seeds in the suspension of seed disinfectants and chemical dosage had no high relation to control the disease. This results suggest that rice varieties, water temperature, and optimal selection of suitable seed disinfectants are very important to control Bakanae disease effectively.

• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.270-276
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• 1994

Mycelial growth resistant isolates of Botryosphaeria dothidea to benomyl showed 99~79% spore germination on the PSA media supplemented with 200~2,100 $\mu\textrm{g}$/ml of carbendazim and thiophanate-methyl to manifest the high cross-resistance in spore germination. Mycelial growth, 23~9 mm in colony diameter, also manifested the high cross-resistance of mycelial growth together with similarity of spore forming cross-resistance. Benomyl resistant isolates BR1, BR2 and BR3, grew 23~10 mm in colony diameter at 330~3,000 $\mu\textrm{g}$/ml of captafol, captan and oxine-copper showing the high double resistance of mycelial growth and spore formation with minor difference. However, within concentration range of the 3 fungicides tested, germinations of all the tested isolates were completely suppressed to show no double-resistance in the fungal spore germination.

• The Plant Pathology Journal
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• v.16 no.3
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• pp.162-165
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• 2000

Screening of effective fungicides, determination of effective fungicide application time and investigation of the emergence of resistant isolates to fungicides were conducted to establish effective chemical control strategy of gray blight of tea (Camellia sinensis) in Korea. Systemic fungicides, such as bitertanol, were effective for controlling gray blight when the fungicides were sprayed within 3 days after cutting tea leaves for harvest. Sprayed immediately after cutting, contact fungicides such as chlorothalonil were also effective, but control efficacy rapidly decreased with lengthening of the intervals between cutting and spraying. Korean isolates of P. longiseta and P. theae were still sensitive to bitertanol or fluazinam. However, the isolates highly insensitive to copper hydroxide or thiophanate-methyl have already emerged in Korea. Therefore, careful attention should be paid to use of fungicides and spraying programs for the effective control of gray blight of tea in Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.2
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• pp.124-129
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• 2020

Sorghum (Sorghum bicolor L.) is an annual crop belonging to Poaceae, and is the fifth-largest crop after maize, wheat, rice, and barley. This study was conducted to establish an efficient seed sterilization method to manage fungal or bacterial infections of germinating sorghum seeds. Two varieties of sorghum seeds (BTx623 and SAP317) were treated with benomyl-thiram and thiophanate-methyl triflumizole which are known to be effective disinfectants for sorghum seeds. For SAP317, the highest germination rate was accomplished with 24-hour treatment of both chemicals at a 200× dilution rate. For BTx623, the highest germination rate was observed after 24-hour treatment at a 200×/400× dilution rate for benomyl-thiram and control/200× for thiophanate-methyl triflumizole. Consequently, the optimal treatment for the seed disinfection in sorghum seeds may be at the dilution rate of 200× or 400× for 24 hours.

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.66-73
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• 2003

Actual pesticide usage in fruit vegetable cultivation was surveyed. Usage trend of in of vidual pesticides was evaluated to provide the data for the development of indicators of environmental impact and the production of safe agricultural products. The amount of the pesticides used for fruit vegetables was revealed in order of fungicide> insecticide> herbicide, showing that the portion of fungicide to the total amount used was about 70 to 80%. Main fungicides used on fruit vegetables were mancozeb, thiophanate-methyl propineb, etc while the insecticides were imidacloprid, milbemectin, methomyl, etc. Main formulation types of pesticide were wettable powder and emulsifiable concentrate. By different fruit vegetables and cultivation patterns, pesticide use per unit area was revealed red pepper (field cultivation, 13.2kg/ha), cucumber (field cultivation, 12.4kg/ha), sweet melon (field cultivation, 11.2kg/ha) as high pesticide use crops, meanwhile, water melon (greenhouse cultivation, 1.2kg/ha), sweet melon (greenhouse cultivation, 2.2kg/ha), strawberry (field cultivation, 2.8kg/ha) as low pesticide use crops.

• Research in Plant Disease
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• v.19 no.1
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• pp.1-6
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• 2013

Optimal spray time, interval and number of preventive fungicides against fruit rots of kiwifruit were investigated at the orchard which both green kiwifruit cultivar 'Hayward' and gold kiwifruit cultivar 'Hort16A' are cultivating side by side during 2009 and 2010 growing seasons in Jeju island, Korea. The highest control efficiency was obtained from benomyl WP and followed by thiophanate-methyl WP and carbendazim+diethofencarb WP. The control efficacies of the fungicides were much higher when applied onto the kiwifruit canopy after the flowering time than before the flowering time but thereafter their control efficiencies were decreased drastically according to delays of spray timing. With increasing spray numbers of the fungicides, the control efficacy increased. However, optimal spray time, interval and number of the preventive fungicides for the effective control of fruit rots of kiwifruit were determined as 4 time-spray schedule with 2-week-interval just after the flowering time on both 'Hayward' and 'Hort16A' cultivars.

• Weed & Turfgrass Science
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• v.6 no.2
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• pp.151-156
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• 2017

Summer patch is the most serious disease at turfgrass field or golf course established with Kentucky bluegrass during high temperature season in Korea. Nevertheless, chemicals for the summer patch control are not yet registered in Korea. We isolated the pathogens from the turfgrass showing typical summer patch symptoms and identified as Magnaporthiopsis poae by using the internal transcribed spacer ITS1 and ITS4 sequences of rDNA. The inhibition rates of the pathogen were investigated for 10 fungicides. As results, the pathogen growth was suppressed when chemicals concentration increased and negatively correlated with incubation period with the chemicals. In triazole group, all chemicals (metconazole, myclobutanil, propiconazole and tebuconazole) treated showed the inhibition rates by 100%. Thiophanate-methyl showed the next highest inhibition effect against a summer patch pathogen. In strobilurin group, pyraclostrobin was the highest suppression effect compared with azoxystrobin and trifloxystrobin. Inhibition effect of fludioxonil and fluxapyroxad on pathogen was similar to the trifloxystrobin. Based on the results, triazole and carboxamide groups are strongly recommended due to the highest inhibition effect on the summer patch pathogen, Magnaporthiopsis poae.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.375-383
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• 2014

Fungi tolerate exposure to various abiotic stresses, including cytotoxic compounds and fungicides, via their ATP-driven efflux pumps belonging to ATP-binding cassette (ABC) transporters. To clarify the molecular basis of interaction between the fungus and various abiotic stresses including fungicides, we constructed a cDNA library from germinated conidia of Colletotrichum acutatum, a major anthracnose pathogen of pepper (Capsicum annum L.). Over 1,000 cDNA clones were sequenced, of which single clone exhibited significant nucleotide sequence homology to ABC transporter genes. We isolated three fosmid clones containing the C. acutatum ABC1 (CaABC1) gene in full-length from genomic DNA library screening. The CaABC1 gene consists of 4,059 bp transcript, predicting a 1,353-aa protein. The gene contains the typical ABC signature and Walker A and B motifs. The 5'-flanking region contains a CAAT motif, a TATA box, and a Kozak region. Phylogenetic and structural analysis suggested that the CaABC1 is a typical ABC transporter gene highly conserved in various fungal species, as well as in Chromista, Metazoans, and Viridiplantae. We also found that CaABC1 was up-regulated during conidiation and a minimal medium condition. Moreover, CaABC1 was induced in iprobenfos, kresoxim-methyl, thiophanate-methyl, and hygromycin B. These results demonstrate that CaABC1 is necessary for conidiation, abiotic stress, and various fungicide resistances. These results will provide the basis for further study on the function of ABC transporter genes in C. acutatum.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.85-89
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• 2003

Current status of pesticide applications in sweet persimmon orchards was investigated through the questionnaire and analysis of the pesticide application records from 62 growers in 2000 and 17 growers in 2001 in Jinju, Sacheon, Changwon, Changyoung, and Gimhae in Korea. Average yearly application was 7.6 times in 2000 and 7.7 times in 2001, concentrated in June and July. The kinds of fungicides and insecticides used were 36 and 34 items in 2000, and 22 and 23 items in 2001, respectively. Application of pesticides was mostly finished by mid-September. Fungicides such as mancozeb, thiophanate-methyl, and benomyl were most frequently used in 2000, and lime sulfur, benomyl and carbendazim in 2001. Insecticides such as deltamethrin, methidathion, and fenitrothion + fenvalerate were frequently used in both years. About one-half of the pesticides being used by the growers was not registered for persimmon in Korea.

• The Plant Pathology Journal
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• v.18 no.4
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• pp.216-220
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• 2002

Seed decay of soybean caused by Diaporthe phaseolorum, Colletotrichum truncatum and Cercospora kikuchii is a serious disease when soybean is harvested under warm and wet weather conditions. Benomyl has been used for controlling the disease, however, benomyl application may be limited due to common occurrence of resistance. The efficacy of 21 fungicides against the pathogens was evaluated in vitro. Among the fungicides tested, benomyl, carbendazim, fluazinam, iprodione+propineb, thiophanate-methyl, and triflumizole were found effective and were evaluated for their ability to control the seed pathogens. Fluazinam completely inhibited mycelial growth at a concentration of 100 $\mu\textrm{g}$/$\textrm{m}{\ell}$ for D. phaseolorum; and at a concentration of 500 $\mu\textrm{g}$/$\textrm{m}{\ell}$ for C. truncatum and C. kikuchii. $EC_90$ values of fluazinam were similar to that of benomyl. Because fluazinam, iprodione+propineb, and triflumizole were found effective against the seed pathogens, these were subjected for field-testing. Suppression of pod and seed infection by fluazinam and iprodione+propineb was as high as that of benomyl without any reduction in agronomic characters of soybean. This study shows that fluazinam and iprodione+propineb may be used in combination with benomyl to control seed pathogens, manage resistance, and ensure production of high quality soybean seeds.