• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.102-107
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• 1998

The objective was to know if seed potato farmers in Kangwon alpine area control weeds effectively and use herbicides properly to control weeds. Seed potato farmers in Pyongcbang, Hoengsong, and Kangnung have noxious weeds, such as marsh pepper, lambsquarters, barnyard grass, mugwort, asiatic dayflower, hairy carbgrass, ladysthumb, common chickweed, field horsetail, and common purslain, in their farmyard. These are controlled by a combination of physical and chemical weed control methods. However, several weeds such as marsh pepper, field horsetail and, mugwort are poorly controlled by 2-fold amount of several herbicides, including paraquat, pendimethalin, and metribuzin (58% of the answered). Herbicides are not selected and used in a proper manner by seed potato farmers: most of farmers selected herbicides by their experience (51% of the answered) and dealers recommendation (34% of the answered), while only a few farmers of the answered took advantage of the Farmers Handbook for Herbicide Application. In addition, the selected herbicides, including non-registered ones such as paraquat and fluazifop-butyl, are applying three to five years in a succession. With these improper selection and usage of herbicides, sixty-seven percent of the answered farmers have experienced crop damage and seventy-five percent have poisoning. We conclude that a systemic educational program for the proper selection and use of herbicides is needed for seed potato farmers in Kangwon alpine area.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.56-62
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• 2000

Effects of sublethal dose of imidacloprid on biological characteristics, such as longevity, fecundity and excretions from brown planthopper (BPH) and its repellency to imidacloprid were examined. Topical application of imidacloprid to BPH at the dose of $LD_{10}$ and $LD_{30}$ (These values were determined at 48 hours after topical application of imidacloprid) was remarkably increased the mortality from 3 days after application and showed over 90% mortality on 4 days after application. Topical application of imidacloprid at dose of $LD_{10}$ (16 days) showed no difference compared to the control (16.9 days) in the longevity, while application of $LD_{30}$ was reduced the longevity of BPH to 13.5 days. Application of sublethal dose of imidacloprid to BPH adults reduced the number of eggs laid per day and for adult stage, and the hatchability of their eggs. By root zone application at the dose of $LC_{30}$, 50% longevity and 40% fecundity was reduced respectively, but showed no effect on number of eggs laid per day. The day on which BPH laid 50 % of eggs in number were 7.6 days at the $LC_{10}$ and 5.9 days the of $LC_{30}$ respectively. Hatchabilities of the groups treated with imidacloprid were lower than that of the control. Topical application to BPH at the dose of $LD_{10}$ did not reduce the amount of excretes, but application at the dose of $LD_{30}$ was reduced 26.5% of excretion compared to the control. Leaf dipping into the solution of concentration of $LC_{10}$ and $LC_{30}$ was reduced 96.4% and 98.0% of excretion, respectively. And root zone treatment at the concentration of $LC_{10}$ and $LC_{30}$ reduced 79.5% and 96.6% of excretion, respectively. Repellency rates of BPH to imidacloprid were 20% regardless of the dose of application.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.256-261
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• 2009

Molinate (S-ethyl hexahydro-1H-azepine-1-carbothioate), a selective, preemergence thiocarbamate herbicide used for grass weed control in rice fields, is being most widely used in Korea. This study was conducted to assess the comparative toxicity of molinate on two aquatic insects, Chironomus riparius and Cloeon dipterum in four larval stages. First-instar larvae of C. riparius appeared to be the most sensitive to acute exposure of molinate with a 48-h $EC_{50}$ of 7.8 mg/L, followed by third instar (48-h $EC_{50}\;=\;22.9\;mg/L$), second instar (48-h $EC_{50}\;=\;25.0\;mg/L$) and fourth instar (48-h $EC_{50}$ > 50 mg/L) larvae. Also, the sensitivity of the larvae of C. dipterum was presented as the same manner of the larvae of C. riparius. The youngest group of larvae of C. riparius appeared to be the most sensitive to molinate, with 96-h $EC_{50}$ values ranged from 14.3 to 24.1 mg/L. The authors assume that the young instar lavae of aquatic insects, Chironomus riparius and Cloeon dipterum are more sensitive to molinate. Also, the authors propose that Mayfly, Cloeon dipterum is well suited as a bioassay organism because it is one of the most vulnerable aquatic insects inhabiting agricultural ecosystem in Korea.

• The Korean Journal of Pesticide Science
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• v.17 no.2
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• pp.94-106
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• 2013

The proficiency testing for the residue laboratories of pesticide registration was conducted in order to improve the reliability and the ability for pesticide residue analysis. On October 2011 the testing was carried out using the soil collected and kept as the moistened state for five years, which is expected to very low residue levels of pesticides. The soil was fortified with chlorpyrifos, metolachlor and procymidone in a manner similar to prepare soil sample for indoor soil degradation test, and then sub-samples were prepared for the distribution to participants. Some of them were randomly selected for confirm of homogeneity and to ensure the stability of samples at room temperature. Samples were consisted of two soil treated as different levels, one of which was used to the assesment and another used to confirm. In addition, provide three standard solutions, respectively concentration of 10 mg/L, and untreated soil. Forty seven institutions submitted results. The medians of results were used as the assigned values for pesticide residues. Fitness for purpose standard deviation of proficiency test was calculated by applying 20% RSD as the coefficient of variation allowed in the soil residue test. Z-score was applied for evaluation of individual pesticides, and the average of the absolute value of the Z-score for the overall assessment of pesticides. Laboratories evaluated the absolute value of the Z-score less than 2 to fit the case of chlorpyrifos and procymidone were 44, metolachlor 40.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.68-74
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• 2017

An analytical method for detecting metamifop residue in paddy water, soil, and rice with high performance liquid chromatography (HPLC) was developed. Water was extracted with ethyl acetate before analyzing by HPLC. Soil residues were extracted with acetone under acidic condition and after purifying with $Extrelut^{(R)}$ NT, and silica SPE, the residue was analyzed by HPLC. For residue analysis in rice, the procedure involved extraction with acetone, purification with $Extrelut^{(R)}$ NT, partitioning between acetonitrile/hexane, purification with silica SPE cartridge, and analysis by HPLC. The limit of detection (LOD) was 1.0 ng, limit of quantitation (LOQ) was 3.0 ng, and method limit of quantitation (MLOQ) were 0.001 mg/L for paddy water, 0.01 mg/kg for rice and soil, respectively. Standard calibration curve shows linearity from 0.05 mg/kg to 5.0 mg/kg ($R^2=0.9999$). The recoveries in fortified paddy water were $91.3{\pm}3.5%$ (0.01 mg/L level) and $93.2{\pm}6.3%$ (0.05 mg/L level). The recoveries in fortified paddy soils were $92.5{\pm}4.0%$ (0.1 mg/kg level) and $92.7{\pm}4.0%$ (0.5 mg/kg level) in soil A, while, $102.3{\pm}4.4%$ (0.1 mg/kg level) and $98.9{\pm}7.9%$ (0.5 mg/kg level) in soil B, respectively. The recoveries in fortified rice were $93.0{\pm}6.9%$ (0.1 mg/kg level) and $85.0{\pm}3.5%$ (0.5 mg/kg level). This method was proved to be effective and can be used to determine the metamifop residue in paddy water, paddy soil, and rice.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.84-89
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• 2017

This study was carried out to investigate residue dissipation of fluquinconazole and flusilazole in field-sprayed tomatoes during greenhouse cultivation and processing. The test pesticide, fluquinconazole+flusilazole 8.5 (7+1.5)% SC, was sprayed onto the tomatoes growing in a greenhouse according to Korea preharvest intervals and then samples were collected on 0 (3 hours after spraying), 1, 3, 5 and 7 days after last application for decline test. For processing test, tomatoes collected at harvest on 5 day after last application were processed to puree and juice. Limits of quantitation of fluquinconazole and flusilazole were 0.005 mg/kg in both tomatoes and their processed products. Recoveries for validation of the analytical methods for fluquinconazole and flusilazole in tomatoes and their processed products ranged from 74.8 to 97.5%. Biological half-lives of fluquinconazole and flusilazole in tomatoes under greenhouse conditions found to be 5.2 and 6.4 days, respectively. Average persistent residue levels of fluquinconazole and flusilazole were 37.34 and 79.53% after washing, 8.95 and 28.75% in filtrates after boiling, 3.58 and 14.66% in puree, and 3.34 and 13.52% in juice, respectively. These results indicated that the test pesticide residues on tomatoes could be largely removed through washing and boiling.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.9-16
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• 2017

A survey was conducted to research on planting system and pesticide spray methods including spray volume, sprayer types, and spray nozzles used in apple orchards. The survey was deployed to 395 farmers in 17 cities and towns including 7 regions which are major producers of apple via interview. Major apple varieties were Fuji (79.2%) and Hongro (50.9%) and high density planting system was mainly used in apple orchards (distance between rows: 4.0-4.5 m (73.1%); planting distance: 1.5-3.5 m (88.6%); canopy height: 3.0-4.5 m (88.2%)). The percentages of sprayer types were 77.6% and 22.1% for speed sprayer (airblast sprayer) and power sprayer, respectively. Spray volumes per 10a were 250-300 L in April, the month of spraying the lowest volume, and 300-400 L in June-August, the months of spraying the highest volume. Significant difference in spray volumes were not observed between conventional planting and high density planting, but regional spray volume showed significant difference. The main nozzles used by apple farmers using power sprayers were super jet nozzle (45%), super wide nozzle (26%), and 2-3 vertical head nozzle (25%). The results will helpful to establish practical agrochemicals management policy including suggestion of pesticide spray volume and evaluation of pesticide residue data and efficacy data.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.3 no.1
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• pp.15-20
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• 2010

Purpose: The goal of this study is to find out how useful ultrasonography is in measuring amount of effusion within the knee joint in comparison with physical examination and simple radiography. Materials and Methods: We evaluated total 60 cases which were suspicious for joint effusion. Average age was 61.3 years. The group was consisted of 22 males and 38 females, and 24 obese people and 36 non-obese people. Stroke test and patella floating test were done as physical examination. Amount of joint effusion was classified into 3 groups in simple lateral radiographic view and ultrasonography was used for recheck-up. Results: 39 cases were found positive in stroke test, and patella floating was shown in 20 cases. In simple lateral radiographic view, 47 cases of grade I, 7 cases of grade II and 3 cases of grade III were checked. Average $7.67{\pm}2.90mm$ amount of effusion was checked by ultrasonography. Amount of fluid in stroke test, patella floating test and simple lateral radiographic view showed close correlation with ultrasonography. Gender did not seem to affect physical examination, but strong correlation was found in female in simple radiography. Obese group showed closer relationship with all 3 exams compared with non-obese group. Physical examination was relatively effective with nonobese group, but not with obese group. And it was not easy to measure the amount of fluid with simple radiographic view, but we could obtain objective data from ultrasonography by measuring the amount of effusion dynamically. Conclusion: We concluded that more objective data was obtained with ultrasonography in comparison with physical examinations and simple radiography in the aspect of measuring amount of joint fluid.

• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.57-68
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• 1994

This experiment was conducted to isolate the mutants from S118 and to investigate the physiological characteristics of R. japonicum mutants. The results obtained were as follows; Based on nodulation and acetylene reduction, nodulation of rhizobia was divided into 4 groups, i.e. slow-nodulation, earlier-nodulation, infrequent-nodulation and non-nodulation. At 5% significant level, the growth of inoculated plant with SM255 was bad, but that of HP277 was good. Root-hairs curling was induced by strains S118 and HP277 on soybean, but not by strain SM255. S118 and SM255 were found to be slow-gorwers and produced alkali, whereas strain HP277 was fast-grower and produced acid in YEM broth. In litmus milk reaction, all strains indicated alkaline reaction, and serume-zone was induced weakly by HP277. All of the strains tested in this experiment utilized sucrose. HP277 and LP268 utilized xylose, whereas S118 and SM255 did not. SM255 showed bad growth in nitrogen carriers however utilization of $Ca(NO_3)_2{\cdot}4H_2O$ by HP277 was possible at 25mM and 10mM level. To compare with S118, the protein band of SM255's cell protein electrophoresis was not developed at 0.62 Rm position.

• Journal of Distribution Science
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• v.9 no.2
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• pp.83-95
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• 2011

Conventional markets in Korea have played a pivotal role in the vitalization of local communities and economies along with the distribution of products. Although many people believe the markets to be disorderly, they are lively and provide local people with things to enjoy, watch and buy. However, superstores have undergone a mushrooming proliferation since Korea opened its gates to multinational superstores in 1996. This phenomenon has caused a crisis for Korea's conventional markets. They have lost their competitiveness because of this environmental change, inefficient management, and their outmoded facilities. Government efforts to revitalize the markets have centered on redevelopment of the facilities, a perspective that has caused not only the fall of the old business districts but also the decline of the distribution function. Under these conditions, the traditional market has re-entered into competition. The Korean government enacted a special law to revitalize the conventional markets and has been implementing many policies to support them since 2003. In 2009, the government amended the law and adopted the Business Improvement District System. The government also changed the official term from 'old markets' to 'Conventional markets'. Despite this legal amendment, though, we still need to re-establish the concept of the Conventional market. Historically, markets grew up spontaneously to dispose of surplus products. Some manmade markets were established through urban planning or as public facilities. Their businesses transactions have always been based on mutual trust between consumers and trades people, the traditional way of commercial dealing. Conventional markets can be defined, then, as creatures of societal necessity where transactions for services and products are based on mutual trust. Problematically, unlisted markets are left out of government support. Although unlisted markets have performed almost the same functions as listed markets, they exist only as a statistic as far as the special law is concerned. In some areas, there are more unlisted markets than unlisted ones. Therefore, it is necessary to establish systematic management methods for the unlisted markets. Some unlisted markets received support in the form of facility improvement from local governments' budgets in the early stage of the special law's enforcement. The current government also assists with safety issues involving unlisted markets; however, the current special law provides no legal framework for unlisted markets. Moreover, consumers cannot tell the difference between unlisted markets and listed ones. Finding a solution to this problemrequires new standards and a wider scope of support by which the efficiency of the market improvement support system might be enhanced.