• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.427-432
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• 2010

Rice bakanae disease caused by Fusarium fujikuroi is one of the most serious rice diseases in Korea. From 2006 to 2009, 118 F. fujikuroi isolates were collected from various regions of rice fields in Korea. Resistance assay of 118 F. fujikuroi isolates to prochloraz, tebuconazole, and benomyl, were performed using agar dilution method. To investigate inhibitory effects of the fungicides, minimum inhibitory concentration of mycelial growth (MIC) and effective concentration inhibiting mycelial growth by 50% ($EC_{50}$) for 118 isolates were calculated using Sigmaplot 8.02 (Antro, SPSS UK, Ltd). Based on the means of $EC_{50}$ values, baseline resistance values were determined as $0.5{\mu}g{\cdot}mL^{-1}$ for prochloraz, $5.0{\mu}g{\cdot}mL^{-1}$ for tebuconazole and $2.5{\mu}g{\cdot}mL^{-1}$ for benomyl. Number of resistant isolates to each fungicide was 17, 19 and 43 for prochloraz, tebuconazole and benomyl, respectively. Furthermore, 4 isolates showed the double resistance to both prochloraz and tebuconazole, 6 isolates to prochloraz and benomyl, and 11 isolates to tebuconazole and benomyl. Isolates CF366 and LF335 isolated from Gyeongbuk province were resistant to the three fungicides tested, prochloraz, tebuconazole and benomyl.

• Research in Plant Disease
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• v.26 no.2
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• pp.79-87
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• 2020

Fusarium wilt caused by Fusarium oxysporum f. sp. fragariae (Fof) is the most important diseases of a strawberry field in Korea. We surveyed phylogenetic analysis, pathogenicity test, and fungicide response about Fof isolates isolated from Korea. Twenty-seven isolates of F. oxysporum isolated from strawberry plants were conducted in this study. Specific amplification by Fof specific primer was confirmed in all 26 isolates except Fo080701 isolate. The nuclear ribosomal intergenic spacer region and the translation elongation factor EF-lα gene sequences of isolates revealed three main lineages. Most of all isolates were contained DNA lineage group 1, but 2 and 3 group was shown only one and three isolates, respectively. All isolates were shown in pathogenicity with cv. Seolhyang. The EC₅₀ mean values of prochloraz ranged 0.02-0.1 ㎍/ml except for Fo080701 and effectively inhibited mycelial growth at low concentrations. The EC₅₀ value of metconazole was also 0.04-0.22 ㎍/ml, showing a similar inhibitory effect to that of prochloraz. The EC₅₀ value of pyraclostrobin was 0.23-168.01 ㎍/ml, which was different according to the strain. In the field trial, boscalid+fludioxonil, fluxapyroxad+pyraclostrobin, and prochloraz manganese were selected as the effective fungicides for controlling Fusarium wilt.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.270-277
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• 1989

In order to elucidate the action mechanism of prochloraz and triadimefon, the mycelia of the Valsa ceratosperma were treated with the compounds in vitro. Analysis by GLC of the sterol extract from Valsa ceratosperma mycelia revealed one major peak and two minor peaks. Their relative retention time(RRT) relative to chloresterol were 1.29, 1.48 and 1.82, The compounds with RRT 1.29 and RRT 1.82 were identified as ergosterol and 24-methylenedihydrolanosterol by GC/MS, respectively. Five ppm of prochloraz and triadimefon applied to mycelia caused decrease in ergosterol content, whereas increase in 24-methylenedihydrolanoserol content in mycelia. The longer treatment time and the higher concentrations of the chemicals resulted in the greater decrease in ergosterol and the greater increase in 24-methylenedihydrolanosterol. Based on the analysis, it is considered that the two chemicals inhibit the ergosterol biosynthesis in Valsa ceratosperma by blocking C-14 demethylation as found previously in other fungi arid yeasts.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.427-434
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• 2009

Analytical method for prochloraz in cabbage, apple, pepper, mandarin, and hulled rice was established by conversion it to 2,4,6-trichlorophenol (TCP). Crop samples were extracted with acetonitrile, and partitioned with dichloromethane. The sample extracts were hydrolyzed with pyridine hydrochloride in a vial by heating for 1 hour, and analyzed with GC-ECD after partitioning with dichloromethane. Method quantification limit (MQL) of prochloraz was 0.01 mg/kg. Recoveries at 0.1 mg/kg level was 105-113% while at 0.5 mg/kg level was 82-87%. In both of the cases CV was less than 10%. Through this procedure soxhlet extraction and refluxing apparatus of conventional method were discarded and simple solvent extraction and small vial were successfully employed, resulting in simple, rapid, economic and more precise method.

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.64-70
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• 2015

In order to control garlic white rot (Sclerotium cepivorum), which threatens garlic production in farmers fields, soil solarization (solar sterilization), sclerotia germination inducers and effective microorganisms as biological control agents, and chemical fungicides have been used. Among them, fungicide has been largely used to reduce garlic white rot. In this study, the antifungal activities of five fungicides, prochloraz(a.i. 25%, EC), tebuconazole (a.i. 25%, WP), flutolanil (a.i. 15%, EC), iminoctadine tris-albesilate (a.i. 40%, WP) and isoprothiolane (a.i. 40%, EC) with different mode of action, in mycelial growth, sclerotia germination and sclerotia production, were tested. The inhibitory effects of the 5 fungicides on the mycelial growth, and sclerotia germination and production of garlic white rot pathogen (S. cepivorum T11-2) were investigated on potato dextrose agar (PDA) and their control efficacies were evaluated on garlic flakes. There was no mycelial growth of S. cepivorum T11-2 on PDA amended with $0.8{\mu}g\;mL^{-1}$ of prochloraz or $100{\mu}g\;mL^{-1}$ of tebuconazole. Also prochloraz and tebuconazole inhibited perfectively the sclerotia germination of the pathogen at 10 and $1.0{\mu}g\;mL^{-1}$, respectively. In spite of a very low activity of isoprothiolane in mycelial growth and sclerotia germination of S. cepivorum T11-2, it showed a good inhibitory activity against sclerotia production of S. cepivorum T11-2 on PDA amended with $1.67{\mu}g\;mL^{-1}$. Prochloraz, tebuconazole and flutolanil showed above 70% of control value when they were treated at $100{\mu}g\;mL^{-1}$ using the garlic flake cutting-method.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.165-171
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• 2023

Potato dry rot is one of the potato storage diseases caused by Fusarium species and is a representative pathological disorder that induced post-harvest loss during storage. Chlorpropham treatment for sprouting inhibition is mainly used for room temperature storage of potatoes for processing. In this study, the inhibitory effect of chlorpropham on Fusarium-induced dry rot of potato 'Dano'. To investigate the mycelial growth rate of the dry rot fungus (Fusarium solani Appel & Wollenw), mycelial growth was investigated in a chlorpropham (5.0, 50.4, 503.8, and 5,038 ppm) and prochloraz (0.1, 1.0, 10.0, and 100.0 ppm) medium containing F. oxysporum mycelia. Mycelia were more inhibited as the concentration of chlorpropham and prochloraz increased during incubation at 20℃, and the inhibition rate was 98.2% and 100% when treated with 503.8 ppm of chlorpropham and 10ppm of prochloraz in 14 days, respectively. Potato Dano tubers inoculated with F. oxysporum were dipped in chlorpropham (5.0, 50.4, and 503.8 ppm) and prochloraz (100 ppm) to investigate the effect of preventing dry rot during cold storage at 20℃ and 4℃ in vivo. The disease diameter of potatoes stored at room temperature (about 20℃) was reduced to 13.0 mm in the prochloraz 100 ppm teatment, and 10.7 mm in the chlorpropham 50.4 ppm treatment compared to 13.7 mm in the control tuber at 70 days of storage. The disease progression in all treatments including control was similar with no statistically significant difference at 4℃ air temperature. From the results of this study, it is considered that treatment with 50.4 ppm of chlorpropham after harvest will be useful for suppressing dry rot of stored potatoes.

• Korean Journal of Medicinal Crop Science
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• v.23 no.6
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• pp.460-467
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• 2015

Background : The aim of the present study was to identify an effective physicochemical control method to reduce Fusarium species infestation in adlay (Coix lacryma-jobi L.) before and after harvesting. Methods and Results : We observed that prochloraz emusifiable concentrate and hexaconazol prochloraz emusifiable concentrate strongly inhibited the mycelial growth of 10 Fusarium species. Strong growth inhibitions and cell lysis were observed following treatment with 4% NaOCl solution. The total number of fungi detected were lower follwing treatment with thiophanatemethyl triflumizole wettable powder ($1.1{\times}10^4CFU/g$), hexaconazol prochloraz emulsifiable concentrate ($1.2{\times}10^4CFU/g$), carboxin thiram dustable powder ($1.6{\times}10^4CFU/g$) and prochloraz emulsifiable concentrate ($1.7{\times}10^4CFU/g$) than in the non-treated control ($7.7{\times}10^4CFU/g$). The reduction of Fusarium fungi varies with the concentration and soaking time of NaOCl solution. Fungal detection was not observed after soaking in NaOCl solution for 24 h and harmful effects were not observed for plant growth by NaOCl after soacking for 6 - 12 h. Conclusion : Soaking seed for 6 - 12 h in 4% NaOCl could be an effective method of disinfectant treatment for the control of Fusarium fungi in adlay seeds.

• The Korean Journal of Pesticide Science
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• v.9 no.1
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• pp.35-40
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• 2005

Damping-off of summer spinach caused by Rhizoctonia solani AG-4 has become a very important disease. For the control of summer spinach damping-off, antifungal activity of thirteen fungicides (pencycuron, trifloxystrobin, pyraclostrobin, azoxystrobin, kresoxim-methyl, validamycin, fluazinam, Benlate-T, flutolanil, cyazofamid, hexaconazole, tebuconazole, prochloraz) were evaluated in vitro and in vivo. Pencycuron, pyraclostrobin, validamycin, fluazinam, Benlate-T, hexaconazole, tebuconazole, and flutolanil significantly suppressed the mycelial growth of the pathogenic fungus. However, trifloxystrobin, azoxystrobia kresoxim-methyl, cyazofamid, and prochloraz did not represent good inhibition on the growth of R. solani. When applied by soil drenching (2,000 mg/L), pencycuron, pyraclostrobin, validamycin, fluazinam, Benlate-T, and flutolanil provided spinach survival ratios of 97.8%, 84.4%, 93.3%, 95.6%, 91.1%, and 86.7%, respectively. Also when treated in seed at 2,000 ing/L, pencycuron and pyraclostrobin displayed survival ratios of more than 85.1%.

• Research in Plant Disease
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• v.17 no.3
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• pp.295-301
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• 2011

The effect of various fungicides on anthracnose of strawberry, caused by Colletotrichum gloeosporioides, was determined in vitro, and in greenhouse and field trials. The $EC_{50}$ values of benomyl were clearly different between two sensitive and resistant groups of isolates. Iminoctadine tris had lower $EC_{50}$ values than mancozeb and propineb as protective fungicides and the response of mancozeb, propineb and azoxystrobin was variable depending on the isolate. In the greenhouse, pre- and post- inoculation fungicide applications significantly reduced disease compared to the non-treated control. Propineb, mancozeb and azoxystrobin were effective in controlling the disease when applied prior to inoculation. Metconazole and prochloraz-Mn treatments as ergosterol biosynthesis-inhibiting fungicides had the lowest incidence of anthracnose. In the nursery field trials in 2009 and 2010, the reduced fungicide spray program provided similar levels of disease control compared to the calendar-based applications with captan. A reduced spray program based on efficacious fungicides such as prochloraz-Mn will be useful for strawberry growers and provide more options for controlling anthracnose in Korea.

• The Korean Journal of Pesticide Science
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• v.5 no.4
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• pp.50-56
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• 2001

In vitro experiments, several fungicides including prochloraz, tebuconazole, fluazinam, fludioxonil, and iminoctadine-triacetate showed more than 85% inhibition of mycelial growth of Pestalotiopsis theae (SP-3). Dichlofluanid and chlorothalonil inhibited mycelial growth at the rate of 10 and 33%, however benomyl did not inhibit mycelial growth of the fungus. Minimum inhibitory concentration(MICs) of iminictadine-triacetate on the mycelial growth of SP-3 isolate was $10{\mu}g/m{\ell}$, but that of P. theae $\underline{MAFF}$ 752002 and P. longiseta $\underline{MAFF}$ 752001 was $1{\mu}g/m{\ell}$. MIC of benomyl, chlorothalonil, dichlorofluanid was $1,000{\mu}g/m{\ell}$, and that of fludioxonil, fluazinam, tebuconazole was $10{\mu}g/m{\ell}$. Conidial germination was inhibited more than 80% in tile medium which contained $1{\mu}g/m{\ell}$ of prochloraz, tebuconazole, fluazinam, fludioxonil, and minoctadine-triacetate. Control values of benomyl, chlorothalonil and dichlofluanid were 40, 60 and 30%, respectively. The controlling effect of iminoctadine-triacetate ($10{\mu}g/m{\ell}$) aganist P. theae (SP-3) in leaf disc test was more than 93%, but benomyl and dichlofluanid could not control leaf blight disease caused by P. theae (SP-3). Tebuconazole, fluazinam, fludioxonil, and iminoctadine-triacetate showed more than 94% of protective and curative effect of leaf blight of sweet persimmon, while, benomyl and dichlofluanid did not show any control effect of the disease.