• 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.

• Applied Biological Chemistry
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• v.7
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• pp.15-19
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• 1966

In order to investigate the stability of the major component of malathion E.C. product, dimethyl S-(1, 2-dicarboxyethoxyethyl) dithiophosphate, toward the quality of glasswares as container, the amount of extractable inorganic components, change of pH and decomposition of the major component of the product were examined during the storage in brown-colored bottles of 100 ml. volume from 3 different companies in comparison with that in a Pyrex flask. 1. Malathion E.C. product was put in three containers A,B and C, and any changes occurring in storage were analyzed at three intervals of 60, 120 and 240 days. 2. It was shown that the amounts of Si, Mg, K, Ca, and Na extracted during these periods of storage differed markedly depending on the qualify of container. Container A revealed ten times higher extraction of Na and Ca than container B and C in a 8-month period. 3. Three commercial containers revealed the shift of pH from 6.5 to alkaline reaction in the storage whereas the Pyrex flask did not show any detectable change. In particular, the pH in container A changed to 9.2 in 60 days and 9.9 in 240 days. 4. The decomposition of malathion was the greatest in container A which showed the decomposition of 7.37% in 240 days. On the other hand, 0.5% was decomposed in the Pyrex flask. 5. The decemposition of malathion had a high correlation with the change of pH of water· in the same container, $r^2$ being 0.899. From the above results, it is concluded that about 10% of malathion E.C. product is decomposed in a year due to the alkaline metallic salts extracted from the container when it is stored in glassware bottles of lower quality.

• Journal of the Korean Society of International Agriculture
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• v.30 no.4
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• pp.305-312
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• 2018

Clubroot, caused by Plasmodiophora brassicae, is one of the most crucial disease in Kimchi cabbage. Screening disease resistant genetic resources is necessary to develop disease resistant cultivars and conduct related research. We have evaluated the development of clubroot to the 120 genetic resources of Kimchi cabbage introduced from World Vegetable Center and five Asian countries using isolate of Plasmodiophora brassicae collected in Haenam fields in Jeollanam-do Province, Rep. of Korea. This isolate was determined race 2 using differential varieties reported by Kim et al., 2016. IT100384 and IT305623 showed strong resistance, lower than disease index (DI) 1.0. IT100385, 100439, and 135407 showed moderate resistance (1.0

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.638-644
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• 2010

A new rice variety 'Haeoreumi' is a japonica rice (Oryza sativa L.) with lodging tolerance, resistance to rice stripe virus (RSV) and bacterial leaf blight (BLB), and high grain quality. It was developed by the rice breeding team of Yeongdeog Substation, National Institute of Crop Science (NICS), RDA in 2008. This variety was derived from a cross between 'Milyang165' with good grain quality and lodging resistance, and 'Haepyeongbyeo' with wind tolerance in winter season of 2000/2001. A promising line, YR22375-B-B-1, selected by pedigree breeding method, was designated as the name of 'Yeongdeog46' in 2005. 'Yeongdeog46' was released as the name of 'Haeoreumi' in 2008 after the local adaptability test that was carried out at nine locations from 2006 to 2008. 'Haeoreumi' has 74 cm short culm length as and medium maturating growth duration. This variety showed resistance to $K_1,\;K_2$, and $K_3$ races of bacterial blight, and stripe virus and moderate resistant to leaf blast disease with durable resistance, and also has tolerance to unfavorable environment such as cold, dry and cold salty wind. 'Haeoreumi' has translucent and clear milled rice kernel without white core and white belly rice, and good eating quality as a result of panel test. The yield potential of 'Haeoreumi' in milled rice is about 5.58MT/ha at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to Middle plain, mid-west costal area, and east-south coastal area.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.435-439
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• 2013

Bacillus amyloliquefaciens M27 was selected as a control agent for the biological control of cucumber powdery mildew. The new mixture of B.amyloliquefaciens M27 and plant (Eucalytus) extract was developed to improve the control activity of B.amyloliquefaciens M27 against cucumber powdery mildew. The mixed formulation showed the high preventive and curative control effect against cucumber powdery mildew when it was diluted at 500 times and foliar-sprayed. Its control effect was higher in preventive spraying than curative spraying. When 500-fold diluted solution of the formulation was sprayed preventively four times at five-day intervals, three times at seven-day intervals and twice at ten-day intervals, the diseased leaf area was shown to be 4.4%, 8.0%, 27.9%, respectively; Whereas the diseased leaf area in the control plot was 45.4%. When the 500-fold diluted formulation was sprayed curatively four times at five-day intervals, three times at seven-day intervals and twice at ten-day intervals after occurred cucumber powdery mildew, the diseases leaf area was 11.5%, 25.2%, 51.8%, respectively; whereas in the control plot, the diseases leaf area was 64.3%. When the 500-fold diluted formulation was treated four times at five-day intervals in the plastic house, its control effect was higher than that treated three times at seven-day intervals and twice at ten-day intervals. As the results, the mixed formulation of B.amyloliquefaciens M27 and plant extract could be a promising candidate of bio-fungicides for the environment-friendly control of powdery mildew of cucumber.

• The Korean Journal of Pesticide Science
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• v.18 no.2
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• pp.115-121
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• 2014

This study was performed to investigate the effect of conidial density, wetness period and temperature on conidial germination, appressoria formation and disease incidence. While there was not significantly correlated between conidial density and temperature, and conidial germination and appressoria formation, there was a significant correlation between those factors and disease incidence. The longer wetness period was, the higher the ratio of conidial germination, appressoria formation and the disease incidence was. The optimum conidial density, temperature and wetness period was $1{\times}10^6$ conidia $mL^{-1}$, $30^{\circ}C$ and 5 days, respectively. In case the wetness period was more than 5 days, the typical symptom was not found on pepper fruits because of the overgrowth of mycelia. Using this fruit assay method, which the pepper anthracnose pathogens were inoculated by spraying spore suspension on non-wounded or wounded pepper fruits, control effect of three fungicides were evaluated against pepper anthracnose by the protective and/or the curative application. Propineb showed high protective control activity, while it showed curative control activity on unwounded fruits, but did not showed curative control activity on wounded fruits. Tebuconazole, one of curative fungicide, showed higher control activity in non-wound inoculation than wound inoculation. Trifloxystrobin, one of strobilurin group, showed high both protective and control activity against anthracnose. In conclusion, we supposed that the newly developed in vitro pepper fruit assay can be used to evaluate antifungal activity of control agents against pepper anthracnose.

• The Korean Journal of Pesticide Science
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• v.7 no.4
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• pp.302-309
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• 2003

Disease control activities of 230 triazolyl quinoline derivatives were investigated against six plant diseases such as rice blast, rice sheath blight, tomato gray mold, tomato late blight, wheat leaf rust (WLR) and barley powdery mildew (BPM). New triazolyl quinolines, KSI-4315 and KSI-4317 exhibited a great in vivo control activities against WLR and BPM, and then were selected for further tests such as preventive, curative, systemic, and persistence against WLR and BPM. The KSI-4315 and KSI-4317 contained MeS moiety and MsO moiety in carbon 4-position, respectively. They possessed both preventive activity and curative activity against WLR and BPM. KSI-4317 showed the better control activity than KSI-4315 against BPM, while KSI-4315 represented the better antifungal activity against WLR. Good persistence of KSI-4315 and KSI-4317 were also observed against WLR and BPM. Persistence of KSI-4315 was similar to that of KSI-4317 on WLR, but KSI-4317 was superior to KSI-4315 on BPM in its persistence. Systemic disease control of KSI-4315 and KSI-4317 was investigated by examining translaminar activity from leaf-under-surface to leaf-upper-surface, systemic activities by leaf to leaf movement and the effect of drenching treatment. Systemicities of KSI-4315 and KSI-4317 were not observed in wheat, but KSI-4317 showed more predominant systemicity than KSI-4315 in barley. These results suggest that KSI-4317 would potentially control WLR and BPM in the fields.

• Korean Journal of Organic Agriculture
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• v.15 no.1
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• pp.109-121
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• 2007

For developing standard method for diease, pest and weed control in environmental friendly 'Ssam' vegetable cultivation, this study was carried out to investigating agriculture material use in organic agriculture and no pesticide cultivation for lettuce, kale, leafy perilla and korean cabbage. The 28.6% of investigated farmer carried out seed sterilization by seed selection with salt solution and soaking in chitosan that not validated. For raising seedling periods, the 55.6% of farmer did not use environmental-friendly agriculture material for, diease control and the 50% of farmer used one time for. pest control. Therefore, the control of disease and pest could be achieved with one or two times use of environmental-friendly agriculture material. Seed sterilization was carried out by soil solar sterilization, one time per year in 71.4% of farmer. Weed was controled by black PE film for weed germination of furrow in many farmer, by man-power weeding for weed of ridge in 85% of farmer and by machine weeding and mulching in some farmer. During cultivation period, the major pest were Aphis gossypii in lettuce, Plutella xylostella in kale, Plutella xylostella and Phyllotreta striolata (Fabricius) in korean cabbage and Pyrausta panopealis (Walke) in feat perilla. The many farmers used environ-mental-friendly agriculture material for control of pest over 10 times for spring season, and more used sold materials in market than home-made materials. In result, it needs to develop standardized method and validate cultivation methods for control of disease and pest, and seed sterilization treatment environmental-friendly 'Ssam' vegetable.

• Research in Plant Disease
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• v.17 no.1
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• pp.19-24
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• 2011

It was identified as a sharp eyespot (Rhizoctonia cerealis) that the isolates from abnormal symptoms in wheat that showed yellowing leaves, necrotic spot on stem base and dead tillers. These isolates have slower growth property and fewer mycelia than Rhizoctonia solani AG-1(1A) (KACC 40106). They showed binuclear cell, same media cultural and DNA characteristics to R. cerealis. They caused same symptoms on leaves and stem base appeared in artificial inoculation test, comparing to diseased wheat fields and also affect to maturing of kernels. They have optimal growth temperature and acidity on the artificial media as $20{\sim}25^{\circ}C$ and pH 5~7, respectively. In the investigation of varietal resistance of Korean winter cereal crops to sharp eyespot, there was no resistant in wheat cultivars that all materials infected over 20% diseased ratio. 12 cultivars including 'Anbaekmil', however, considered to moderate resistance with 20 to 30% infection ratio. The others crops using in feeding, whole crop barley, oat, rye and triticale were resistant below 15% diseased degree except the rye that showed over 50% infection rate. It was the first evaluation to sharp eyespot resistance for the Korean feeding crop cultivars. Most tested Korean barley cultivars for malting and food were moderate and susceptible to the sharp eyespot. Only 3 hulled barley, 'Tapgolbori', 'Albori' and 'Seodunchalbori', showed resistance with less than 10% diseased ratio. All tested naked barley cultivars showed susceptible response to the disease.

• Korean Journal of Organic Agriculture
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• v.18 no.1
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• pp.93-104
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• 2010

This study was conducted screening of the population densities of fungal pathogens and insect and observed the disease symptoms on the organic sweet corn seed producing field from 2008 to 2009. The dissemination spores, Alternaria sp., Cladosporium sp., Helminthosporium sp., Pyricularia sp., Collectotrichum sp., and Bipolaris sp., were detected and the three fungal spores from the front were observed for whole growth stage. Seed and seedling diseases were shown as the rotted seed and damping-off seedling caused by Penicillium sp. and Rhizoctonia sp.. The larva of Black cutworm cut down the root crown of seedlings. The damaged plants were ranged from 14% to 16%. On the Oriental corn borer, the population densities and the percentage of damaged plants were showed a low difference between two sweet corn varieties. The population densities of Oriental corn borer were scored as from 3.5 to 20.5 in 2008 and from 0.5 to 6 in 2009. Also the percentage of damaged plants were significantly increased until harvesting stage and was recorded from 7.5% to 21% in 2008 and from 1% to 46% in 2009. On the Corn leaf blight, the percentage of diseased plant were scored from 7% to 34% in 2008. The first occurrence of date was after June 18, and the percentage of diseased plant was continuously increased after August 21 and the values of diseased plants was ranged from 56% to 69% in 2009. On common smut, the percentage of diseased plant was recorded from 5% to 15% in 2008, and the first occurrence date were delayed as 17 days (July 17) and were showed less than 8% of diseased plants in 2009. Corn Southern Leaf spot was scored as average 11% at early stage and showed high score as 62% at September 19 in 2008. In 2009, the first occurrence date were advanced about 20 days (after June 8), and continuously increased up to 86% in 2009.