• Research in Plant Disease
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• v.13 no.3
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• pp.170-176
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• 2007

Effects of fungicides on the mycelial growth of Botrytis cinerea isolated from ginseng leaves were investigated by an agar dilution method. By using a agar dilution method, it was investigated the effect of fungicides, procymidone, carbendazim and the mixture with both of carbendazim and diethofencarb, on the mycelial growth of Botrytis cinerea isolates, which were isolated from infected leaves of ginseng in 2005 and 2006. With MIC (minimum inhibiton concentration) of procymidone against B. cinerea, pathogens were divided into two groups. While one showed the low MIC between 0.8 and $4.0{\mu}g/ml$, the other showed higher MIC above $20{\mu}g/ml$. In terms of the inhibition ratio of mycelial growth at the indicated concentration of procymidone, isolates of B. cinerea were divided into three groups; the sensitive, the intermediate resistant, and the resistant group. Each group was differentiated by $EC_{50}$; the sensitive group showed below $2.0{\mu}g/ml$, the intermediate resistant group between 2.0 to $5.0{\mu}g/ml$, and resistant group above $5.0{\mu}g/ml$. Compared with the ratio of resistant isolates of B. cinerea in 2005, the ratio in 2006 increased from 19.3% to 27.5%. Furthermore, the average $EC_{50}$ value of them increased from $10.0{\mu}g/ml$ in 2005 to $237.3{\mu}g/ml$ in 2006. The ratio of isolates showing the multiple resistance between procymidone and carbendazim was 40.2%, whereas the ratio was 4.0% showing the multiple resistance in the mixture.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.277-281
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• 2012

Bacillus sp. NAAS-1 isolated from the field of Chili pepper was tested for biocontrol activity against anthracnose pathogen of Chili pepper caused by Colletotrichum acutatum. The antifungal activity of Bacillus sp. NAAS-1 culture broth was compared with synthetic fungicide containing carbendazim (40%) and kasugamycin (3.45%). Bacillus sp. NAAS-1 showed a similar fungicidal activity against the anthracnose pathogen at the concentration of 50 ${\mu}L/mL$ in comparison to the fungicide containing carbendazim (40%) and kasugamycin (3.45%) using a cup method. Bacillus sp. NAAS-1 also exhibited its potent fungicidal activity against the anthracnose in vivo test at the concentration of 50 ${\mu}L/mL$ when compared to the fungicide containing carbendazim (40%) and kasugamycin (3.45%).

• Research in Plant Disease
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• v.12 no.3
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• pp.240-248
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• 2006

Control of white rot which is one of the most serious apple diseases in Korea has mainly relied on periodical spray of protective fungicides. As the main inoculum source of the disease is pycnidiospores produced in the warts formed on affected stems of apple tree, it can be conceivable that inhibition of spore production might be an effective means for controlling the disease. Inhibitory efficacy of eight selected fungicides against sporulation of the fungus was assessed by counting the number of spores produced at detached warts treated with the fungicides of recommended dilution. They showed diverse effect on sporulation. Carbendazim and azoxystrobin suppressed sporulation almost completely, the former irreversively. Thiram and folpet promoted sporulation as producing much more number of spores than untreated control. Others showed almost no effect on sporulation. Effects of suppression and promotion in the sporulation shown by the fungicides on the control of white rot were examined by incidences of disease and infection at the plots adopted the spray programs of which the fungicide at late May was substituted by carbendazim, azoxystrobin, folpet and thiram, respectively. Disease incidence and infection frequency at the plots sprayed former two chemicals which suppressed sporulation were much lower than those of the plots adopted latter two chemicals and untreated plot at which the fungicide spray was skipped at that time. These facts were reconfirmed in the experiments conducted with carbendazim and thiram, in which 100 fruits were bagged just prior to each spray from late May to late July for elucidating the effect of the two fungicides on the action of subsequent ones. Disease incidence and infection frequency on the fruit bagged just prior to each spray were gradually increased as the seasons going on. The increase rate at the carbendazim plot was much lower than that of thiram. Especially, the fruit infected till late July at the carbendazim plot were almost completely cured by the three fungicides, iminoctadine-triacetate, tebuconazole and samzinwang, a combined formular of iminoctadine-triacetate and difenoconazole, sprayed at late July and hence. In thiram plot, infected fruit were also cured by the 3 fungicides but not remarkable. From these results, it can be concluded that control efficiency of white rot can be greatly enhanced by selecting the fungicide capable of suppress the sporulation of white rot fungus at the season when the mass dispersal of spores is not initiated.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.347-353
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• 2005

Pesticide risk assessment for pesticide operators as well as for consumers has become one of the pesticide regulatory tools to reduce any unreasonable adverse health effects from pesticide use. The risk for pesticide operators can be quantified by comparing the acceptable operator exposure level(AOEL) with exposure level during pesticide application. This study is to evaluate the risk of benzimidazole fungicides application worker. The exposure level of pesticide applicators were calculated using Japanese operator exposure study tested with EPN 45% EC. The AOELs for pesticides were obtained dividing relevant lowest no observed abuse effect levels(NOAELs) for the exposure scenario into uncertainty factor, 100. For the non-cancer and cancer occupational risk assessment, $Q_1^*$ produced by US/EPA and life time average daily dose(LADD) calculated from average daily dose(ADD), treatment days per year, worked years for life time were used. Operator exposure for benzimidazole fungicides application were benomyl 0.2, carbendazim 0.36 and thiophanate-methyl 0.42 mg/kg/day. Short-term AOELs for benomyl, carbendazim and thiophanate-methyl were 0.3, 0.1, and 0.2 mg/kg/day, and long-term AOEL were 0.025, 0.025, 0.08 mg/kg/day, respectively. LADDs were benomyl 0.0038, carbendazim 0.0067, thiophanate-methyl 0.0081 mg/kg/day. The ratios of exposure to AOEL were $0.28{\sim}1.5$ for short-term and $3.73{\sim}9.88$ for long-term. Cancer risk for operator were $9.12{\times}10^{-6}$ for benomyl, $1.61{\times}10^{-5}$ for carbendazim and $1.13{\times}10^{-4}$ for thiophanate-methyl by the standard application scenario. The result showed 3 fungicides exceed the risk criteria, $1.0{\times}10^{-6}$. The above risk assessments were based upon conservative assumptions and therefore are believed to be protective of the applicator. To refine the risk at the more actual conditions, further risk assessment with more realistic data would be needed.

• Korean Journal Plant Pathology
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• v.14 no.4
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• pp.367-370
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• 1998

Monilina fructicola, the brown rot fungus of stone fruits, was isolated from overwintering mummies and peduncles on peach trees from February to March, 1998. The resistant population of these isolates to benzimidazole (benomyl, carbendazim and thiophanate-methyl) and dicarboximide (iprodione, vinclozolin and procymidone) was examined. Among 417 isolates, the incidence of isolates resistant to benomyl, carbendazim, and thiophanate-methyl were 45 (10.8%), 47 (11.3%), and 46 (11.0%), respectively. Forty two (10.0%) isolates showed cross-resistance to benzimidazole fungicides. On the other hand, the resistant isolates against iprodione, vinclozolin and procymidone were 186 (44.6%), 1 (0.2%) and 150 (36.0%), respectively. Among the isolates, 116 (27.8%) showed cross-resistance to iprodione and procymidone. Moreover, 27 (6.5%) of 417 isolates showed double-resistance to both benzimidazole (benomyl) and dicarboximide (iprodione).

• The Plant Pathology Journal
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• v.15 no.6
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• pp.340-344
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• 1999

Fungicide-resistant isolates of Monilinia fructicola grew readily on media amended with 0.1, 1.0, 10, 100 and $1,000\mu\textrm{g}$ a.i./ml of carendazim, benomyl, or thiophanate-methyl. However, sensitive isolates did not grow on media amended even with $0.1\mu\textrm{g}$ a.i./ml of carbendazim, $1.0\mu\textrm{g}$ a.i./ml of benomyl or thiophanate-methyl. The fitness compositions including mycelial growth on fungicide-free medium, sporulation on fungicide-free medium and pear, and virulence on pear were not different between resistant and sensitive isolates. The resistant isolates persisted carbendazim resistance during multiple subdulturing and long term storage. The competitive ability of resistant isolates obtained from peach orchards in Korea was similar to those of sensitive isolates.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.65-65
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• 2002

• The Plant Pathology Journal
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• v.25 no.1
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• pp.13-20
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• 2009

Ninety isolates of Colletotrichum species from new persimmon tree twigs and 50 isolates from pepper plant fruits were isolated via single-spore isolation. Of the 140 isolates, 26 were examined for mycelial growth, carbendazim sensitivity, and ITS sequence. Four of the isolates from the persimmon trees, which were cultivated exclusively in an orchard, showed fast mycelial growth and sensitivity to carbendazim, while five of the pepper isolates showed slower mycelial growth and were resistant to the fungicide. However, 17 isolates from persimmon trees cultivated with pepper plants in the same orchard showed slow mycelial growth like the pepper isolates and they were sensitive to carbendazim like the persimmon isolates. ITS sequence analysis of these 27 isolates led to the identification of the 22 persimmon isolates as C. gloeosporioides and the five pepper isolates as C. acutatum. PCR with species-specific primers confirmed that the 90 isolates from persimmon were C. gloeosporioides whereas the 50 isolates from pepper were C. acutatum. The 90 persimmon isolates of C. gloeosporioides and 50 pepper isolates of C. acutatum were compared by a wound inoculation test to determine their capacity for host cross-infection. All of the C. acutatum isolates from pepper caused typical symptoms of anthracnose on the fruits of pepper plants and twigs of persimmon; they differed from the C. gloeosporioides isolates from persimmon, more than 90% of which were able to infect only persimmon. Amplified fragment length polymorphism analysis revealed the existence of two groups (C. gloeosporioides and C. acutatum isolates group). At 80% genetic similarity, the C. gloeosporioides group was defined within four clusters, while the C. acutatum group was within three clusters. However, these clusterings were unrelated with the virulence of Colletotrichum species against pepper fruits.

• The Plant Pathology Journal
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• v.34 no.2
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• pp.121-125
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• 2018

Maize (Zea mays L.; 2N=20) is major staple food crop grown worldwide adapted to several biotic and abiotic stresses. Maydis leaf blight (MLB) and banded leaf and sheath blight (BLSB) are serious foliar fungal diseases may cause up to 40% and 100% grain yield loss, respectively. The present studies were undertaken to work out the efficacy of chemicals, botanicals and bioagents for the management of MLB and BLSB under field condition for two seasons Kharif 2014 and 2015. Five molecules (propiconazole 25 EC, hexaconazole 25 EC, carbendazim 50 WP, mancozeb 75 WP and carbedazim 12 WP + mancozeb 63 WP), two bioagents i.e. Trichoderma harzianum and T. viridae and three botanicals namely azadirachtin, sarpagandha and bel pathar were tested for their efficacy against MLB. Eight newer fungicides viz., difenconazole 250 SC, hexaconazole 5 EC, carbendazim 50WP, validamycin 3 L, tebuconazole 250 EC, trifloxystrobin 50 WG + tebuconazole 50 WG, azoxystrobin 250 EC and pencycuron 250 SC were evaluated against BLSB. Analysis revealed significant effects of propiconazole at 0.1%, carbendazim 12 WP + mancozeb 63 WP at 0.125% and sarpagandha leaves at 10% against MLB pathogen, whereas validamycin at 0.1% and trifloxystrobin 25 WG + tebuconazole 50 WG at 0.05% were found effective against BLSB. The slow rate of disease control virtually by the bioagents might have not shown instant effect on plant response to the yield enhancing components. The identified sources of management can be used further in strengthening the plant protection in maize against MLB and BLSB.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.429-436
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• 2005

As Sclerotinia sclerotiorum causing cucumber sclerotinia rot was the fastest in the mycelial growth at $25^{\circ}C$, its pathogenicity was strong at the same temperature among several temperatures. All the isolates of Sclerotinia sclerotiorum showed a strong pathogenicity against cucumber fruits, which was confirmed by a disk assay and a wound assay. A wound assay was superior to a disk assay to develop the assay system for assessing the fungicidal activity of several fungicides against Sclerotinia sclerotiorum. In a disk assay, it was very difficult to assess the fungicidal activity, because the pathogenicity of isolates used in the experiment was very strong. At 500 and $3.0{\mu}g/mL$, the activity of dichloflouanid and the mixture of carbendazim and diethofencarb against cucumber sclerotinia rot was 14.3 and 42.3%, respectively, by using a disk assay. However, at same concentration two fungicides showed the high controlling activity as 100 and 92.5%, through a wound assay in a laboratory. Also, the activity of two fungicides was good against cucumber sclerotinia rot in the greenhouse where cucumber plants were cultivated in the field, showing the control value as 91.1 and 82.9% at 100 and $825{\mu}g/mL$, respectively. All the isolates of Sclerotinia sclerotiorum from cucumber fruits sampled in the polyvinyl house were subjected to monitoring for the resistance to 7 fungicides. The $EC_{50}$ value of 7 fungicides was as follows: fenhexamid; $0.13{\mu}g/mL$, procymidon and iprodione; 0.18 and $0.24{\mu}g/mL$, carbendazim and the mixture of carbendazim and diethofencarb; 0.13과 $0.05{\mu}g/mL$, iminoctadine and dichlofluanid; 1.94 and $8.95{\mu}g/mL$. Ultimately it was not found that resistant isolates of Sclerotinia sclerotiorum were appeared in the field.