• Bulletin of the Korean Chemical Society
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• 제28권3호
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• pp.369-372
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• 2007

A fast and simple high-performance liquid chromatography (HPLC) method for the simultaneous determination of four pesticides having fungicide properties has been proposed for Panax ginseng, C. A. Meyer grown for 4, 5, or 6 years. Analytical separation was performed on C18 columns using ultraviolet detector under gradient conditions. Spiked blank samples were used as standards to counteract the matrix effect observed in the chromatographic determination. The HPLC response for all pesticides was linear, with determination coefficients > 0.9986. The average rate of recovery for pesticides spiked with 2 fortification levels was > 72% with relative standard deviations < 9%. The limits of quantification (LOQ) ranged from 0.03 to 0.16 ppm. These LOQs were lower than the respective maximum residue limits (MRL) established by the Korean Food and Drug Administration (KFDA), except for cyazofamid. The proposed method was used to determine pesticide residue levels in samples of ginseng obtained from Jeonnam Province (Republic of Korea). None of the pesticides were found in ginseng samples grown for 4, 5, or 6 years.

• The Plant Pathology Journal
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• 제30권1호
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• pp.82-89
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• 2014

In 2009-2010, unusual symptoms were observed on Pleurotus eryngii grown in mushroom farms in Gyeongnam Province, Republic of Korea. One of the main symptoms was a cobweb-like growth of fungal mycelia over the surface of the mushroom. The colonies on the surface rapidly overwhelmed the mushrooms and developed several spores within 3-4 days. The colonized surface turned pale brown or yellow. The fruit body eventually turned dark brown and became rancid. Koch's postulates were completed by spraying and spotting using isolated strains. The phylogenetic tree obtained from the internal transcribed spacer sequence analysis showed that the isolated fungal pathogen corresponded to Cladobotryum mycophilum (99.5%). In the fungicide sensitivity tests, the $ED_{50}$ values for the isolate with respect to benomyl and carbendazim were from 0.29 to 0.31 ppm. Benzimidazole fungicides were most effective against C. mycophilum, a causal agent of cobweb disease in P. eryngii.

• The Plant Pathology Journal
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• 제23권3호
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• pp.187-192
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• 2007

The anthracnose disease on pepper fruits in Korea was caused by Colletotrichum acutatum as well as C. gloeosporioides. Since C. acutatum showed less sensitivity to benomyl, it was analyzed whether the less sensitivity was given by the same mechanism for the fungicide resistance of C. gloeosporioides. The isolates of C. acutatum were less sensitive to the three benzimidazole fungicides tested, benomyl, carbendazim, and thiophanate-methyl. However, the of C. acutatum isolates were different from the resistant isolates of C. gloeosporioides in their response to diethofencarb, one of N-phenyl-carbamates; the former was still less sensitive to diethofencarb than the latter. The differences in the resistance mechanisms in two species were conspicuous in sequence analysis of the tub2 genes. The genes from C. acutatum did not show any non-synonymous base substitutions at the regions known to be correlated with the benzimidazole-resistance. All of these data may indicate that the less sensitivity of C. acutatum to benomyl is based on different mechanism(s) from that of C. gloeosporioides.

• 환경분석과 독성보건
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• 제21권4호
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• pp.304-315
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• 2018

Located in Gimhae, Hwapo is the biggest riverine wetland in the province of Gyeongsangsam-do, Korea, and is a major habitat for various species. However, it is suspected that various pollutants enter the wetlands from agricultural and industrial areas. This study identifies major organic pollutants in this wetland and their sources using high performance liquid chromatography-high resolution mass spectrometry during one summer season. Forty-five substances were selected for quantitative analysis using target screening, and other non-selected compounds were screened using suspect and non-target screening methods. The results were that 21 and 17 targeted substances were detected in July and August, respectively. Major pollutants in July and August were oxadiazon (July: 17-220 ng/L, August: 66-460 ng/L), carbendazim (July: 10-110 ng/L, August: 64-520 ng/L), caffeine (July: 33-1,100 ng/L, August: 56-580 ng/L), and niflumic acid (July: 23-75 ng/L, August: 42-290 ng/L). Sampling sites S4 in July and S2 in August were the major inflow points. Ten substances (tricyclazole, hexaconazole, diuron, fexofenadine, irbesartan, simetryn, cimetidine, valsartan, tebuconazole, and benzotriazole) and four metabolites (valsartan acid, azoxystrobin acid, TEB_M324c, and 2-aminobenzimidazole) were tentatively identified through suspect and non-target screening, respectively.

• The Plant Pathology Journal
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• 제37권4호
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• pp.356-364
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• 2021

This study was to investigate defense mechanisms on cassava induced by salicylic acid formulation (SA) against anthracnose disease. Our results indicated that the SA could reduce anthracnose severity in cassava plants up to 33.3% under the greenhouse condition. The 𝛽-1,3-glucanase and chitinase enzyme activities were significantly increased at 24 hours after inoculation (HAI) and decrease at 48 HAI after Colletotrichum gloeosporioides challenge inoculation, respectively, for cassava treated with SA formulation. Synchrotron radiation-based Fourier-transform infrared microspectroscopy spectra revealed changes of the C=H stretching vibration (3,000-2,800 cm^-1), pectin (1,740-1,700 cm^-1), amide I protein (1,700-1,600 cm^-1), amide II protein (1,600-1,500 cm^-1), lignin (1,515 cm^-1) as well as mainly C-O-C of polysaccharides (1,300-1,100 cm^-1) in the leaf epidermal and mesophyll tissues treated with SA formulations, compared to those treated with fungicide carbendazim and distilled water after the challenged inoculation with C. gloeosporioides. The results indicate that biochemical changes in cassava leaf treated with SA played an important role in the enhancement of structural and chemical defense mechanisms leading to reduced anthracnose severity.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권2호
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• pp.183-188
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• 2002

Anti-fungal potential of 5 plant extracts viz., Eucalyptus citriodora, Allium sativum, Cassia sophera, Chromolaena odorata and Datura metel on the growth of mulberry brown leaf spot pathogen Myrothecium roridum were examined. Except fur the aqueous extract of Allium bulb, ethanolic leaf extract of all other plants more efficiently reduced the colony growth of the fungus on potato-dextrose-agar, Of which, Allium and Eucalyptus extracts were more effective. Initiation of radial growth of M. roridum on solid media was deferred maximum 6 days by ethanolic Eucalyptus extract and 4 days by aqueous Allium extract at $0.4 mg.ml^{-1}$. In the liquid media amended with Eucalyptus extract ($0.4 mg.ml^{-1}$) complete inhibition of sporulation was noticed upto 8 days, and initial inhibition of mycelial bio-mass generation was considerably diminished with time and reduction was 1.3 fold 14 days after application. While, complete inhibition of mycelial growth for 6-14 days was recorded with $\geq$0.1 mg.ml$^{-1}$ commercial eucalyptus oil. However, rejuvenation of growth appeared when fungus was re-inoculated in fresh media. Post-inoculate application of different doses Of Eucalyptus and Allium extracts significantly (p < 0.05) reduced the disease severity in pot-ted mulberry. However, persistence of the effect up to 28 days was apparent at $\geq$ 1.0 mg.ml$^{-1}$ and effectively was on par with carbendazim (1 mg.ml$^{-1}$ ). Almost equal control ability of 1.0 mg.ml$^{-1}$ Eucalyptus extracts can be achieved by ca. 10 times lowered dose of commercial eucalyptus oil. It seems, the toxic principle of E. citrodora to M. roridum is fungistatic in nature and may have essential oil based origin.

• 한국환경농학회지
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• 제36권3호
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• pp.217-221
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• 2017

BACKGROUND: For the food safety of cultivated mushroom, information on the safety of agricultural by-products imported as medium substrates for mushroom cultivation is urgently needed. Therefore, this study was performed to detect the presence of heavy metals, residual pesticides, and nutrient component in the imported medium substrates. METHODS AND RESULTS: Six kinds of medium substrates imported from nine countries from 2015 to 2017 were investigated. A mercury analyzer MA-2000 and an inductively coupled plasma spectrometer OPTIMA 7000DV were used to analyze mercury, lead, arsenic, copper, nickel and cadmium. All of these heavy metals were detected at lower level than heavy metal tolerance standard level of by-product fertilizer in Korea. When 246 kinds of residual pesticides were examined by GC and HPLC, imidacloprid, thiamethoxam and carbendazim were detected from Egyptian beet pulp, Indian cottonseed meal and cottonseed hull, respectively. The content of nutrient components (water, crude ash, crude fat, crude protein and crude fiber) varied among imported countries and the medium substrates. CONCLUSION:The presence of heavy metals and residual pesticides in imported medium substrates for mushroom cultivation was confirmed. For the safe production of mushroom, this study shows that imported medium materials for mushroom cultivation need to be managed through continuous monitoring.

• Journal of Applied Biological Chemistry
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• 제44권3호
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• pp.147-153
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• 2001

Methanol extracts from 51 fruits were tested for their fungicidal activities against six phytopathogenic fungi in a greenhouse. The efficacy varied with both the plant pathogen and fruit species used. At 10 and 5 mg/pot, methanol extracts of Poncirus trifoliata peel and seed gave over 80% control values against Pyricularia grisea, and strong fungicidal activities against Rhizoctonia solani were showed from the extracts of Citrus paradisi peel and Punica granatum leaf. In a test with Botrytis cinerea at 5 mg/pot, the extracts of C. sinensis seed and D. kaki leaf produced potent fungicidal activities, and the extracts of C. crenata peel and leaf, Ch. sinensis seed, P. trifoliata peel, and Z. jujuba leaf had strong fungicidal activities. At 5 mg/pot, strong fungicidal activities were produced in the extracts of P. trifoliata peel and seed against Phytophthora infestans and in the extracts of P. ussriensis var. macrostipes fruit and seed, C. crenata peel, C. crenata leaf, C. paradisi peel, P. trifoliata peel, P. granatum peel, and Z. jujuba leaf against Puccinia recondita. In a test with E. graminis, potent activities at 10 mg/pot were produced from the extracts of Ch. sinensis seed, C. sinensis seed, P. trifoliata leaf, P. ussriensis var. macrostipes fruit and seed, and Vitis vinifera seed. In the control effect of seven extracts against B. cinerea strains resistant to carbendazim, procymidone, and diethofencarb, extracts of C. crenata peel and leaf, Ch. sinensis seed, and P. trifoliata peel were highly effective against all strains of B. cinerea. Furthermore, potent fungicidal activities were produced from the extracts of C. sinensis seed and D. kaki leaf against the SSR, SRR, and RRS, and Z. jujuba leaf against the SSR and RRS strains. As a naturally occurring fungicide, these fruit-derived materials could be useful as new fungicidal products against phytopathogenic fungi.

• The Plant Pathology Journal
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• 제22권1호
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• pp.7-10
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• 2006

Anthracnose severely occurred on begonia (Begonia semperflorens Link.) nurseries in Gyeongju, Gyeongbuk in July, 2004. More than $80\%$ of begonia seedlings were diseased in the greenhouse surveyed and diseased leaves per plant were $12.1\%$ in average. Yellowish spots occurred on the leaves of begonia as initial symptoms, and they coalesced irregularly to form large brown pleomorphic lesions. Severely infected leaves were defoliated, resulting in abnormal growth of the entire plant. Colletotrichum sp. was repeatedly isolated from the diseased plants and was identified as Colletotrichum acutatum on the basis of the mycological characteristics on potato dextrose agar and RAPD analysis. Pathogenicity of the fungus was also confirmed by artificial inoculation on healthy plants. The optimum temperature for mycelial growth of C. acutatum was around $25^{\circ}C$. The fungus was sensitive to azoxystrobin, bitertanol, diethofencarb-carbendazim, difenoconazole and tebuconazole. This is the first report on the anthracnose of begonia caused by C. acutatum in Korea.

• 농약과학회지
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• 제18권4호
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• pp.336-341
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• 2014

국내에서 생산되는 과일 중 농약의 잔류특성과 인체에 미치는 영향을 파악하기 위하여 2010년 사과, 복숭아, 배, 포도, 감귤에 대한 농약잔류 모니터링을 수행한 후 잔류농약의 검출량과 위해성지수를 이용하여 안전성을 평가하였다. 시료는 2-5지역의 주산단지에서 채취하였으며, 시료 중 잔류농약을 LC/MS/MS를 이용하여 분석하였다. 사과의 경우 acetamiprid 등 18종의 농약성분이 검출되었고 총 위해지수가 0.55로 위해우려 수준은 아니었으나 조사한 과일 중 가장 높았다. 감귤의 경우는 carbendazim 등 17종의 농약성분이 검출되었으며, 위해지수는 0.37이었다. 복숭아, 포도 및 배는 각각 12, 10, 8종의 농약이 검출되었으나 위해지수는 0.066, 0.025, 0.008로 낮은 것으로 평가되었다. 따라서 국내에서 생산되는 사과, 복숭아, 배, 포도, 감귤 중의 잔류농약에 의한 위해성은 낮은 것으로 판단되었다.