• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.126-136
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• 1998

For the purpose of effective control strategy of the melon aphid, Aphis gossypii and the diamondback moth, Plutella xylostella, thiamethoxam and 3 other insecticides in different classes were used with bioassay test methods in laboratory and greenhouse. They were examined to evaluated and compared with contact toxicity, stomach toxicity, rapid action, systemic action, and residual effect of imidacloprid, thiamethoxam (nicotinoids), acephate (organophosphorates), and carbosulfan (carbamates). As results of contact toxicity responses of A. gassypii against 4 insecticides using a spray application method, $LC_{50}$ values of acephate, carbosulfan, imidacloprid and thiamethoxam were 41.9, 5.2, 1.1, and 0.7 ppm. respectively. In the evaluation of stomach toxicity response of P. xylostella using a leaf-dipping method, with the 2nd instar larva $LC_{50}$ values of imidacloprid, thiamethoxam and acetamiprid were 64.9, 24.6 and 15.2 ppm, with the 3rd instar larva were 125.2, 42.7 and 27.8 ppm. and with the 4th instar larva were 241.1, 44.5 and 23.9 ppm, respectively. In the case of rapid action to A. gossypii using a spray application method after inoculation, $LT_{50}$ values of imidacloprid, thiamethoxam, carbosulfan, and acephate were 26.6, 28.0, 30.3, and 41.7 min. respectively. Otherwise, in the inoculation after applying compounds, $LT_{50}$ values of thiamethoxam, imidacloprid, and carbosulfan were 95.5, 118.0, and 122.9 min. respectively. Evaluating to systemic action from the abaxial surface to the adaxial surface of red pepper leaf with spray method, $LT_{50}$ values of thiamethoxam, imidacloprid, and carbosulfan were 162.2, 168.9, and 564.1 min. respectively. For the systemic action from the lower leaves to the upper leaves on red pepper, $LT_{50}$ values of carbosulfan, thiamethoxam, imidacloprid, and acephate were 2.3, 2.9, 3.0, and 8.8 days, respectively. In red pepper plant, $LT_{50}$ values of carbosulfan, imidacloprid, thiamethoxam, and acephate on the systemic action from the roots to the upper leaf were 0.6, 1.0, 1.0, and 13.8 days, respectively. As these results, it might be that thiamethoxam was excellent on systemic effect in red pepper. For the evaluation of residual effect on red pepper with A. gossypii, thiamethoxam and imidacloprid maintained high control effects as over 80% upto 10 days after treating compounds.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.04a
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• pp.148-149
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• 2000

황금배는 1967년에 신고에 이십세기를 교배하여 1977년 1차선발과 1982년 2차선발을 거 쳐 1984년 최종선발, 명명한 품종으로, 당도가 높고 육질이 부드러워서 최근 몇년 사이에 캐 나다, 미국, 호주, 그리고 유럽 지역에서의 수요가 급증하고 있는 수출전망이 매우 밝은 품 종 중의 하나이다(92년 재배면적 lOha 수출량 5. 8M/T, 95년 재배면적 150ha 수출량 2 200.6M/T), 황금배는 비교적 대과이고 과형은 원형에 가까운 편원형으로서 사과 골든처럼 과피가 황금색이고 과육은 연황백색으로 투명하며 보기에 극히 미려한 특징이 있다. 아울러 육질이 유연치밀하고 과즙이 극히 많으며 당도가 높아 13$^{\circ}$ Bx이상, 15도 Bx까지 측정되는 둥 감산이 적화되어 맛이 극히 우수하다. 그러나 이러한 황금배는 동녹, 흑반병 등 병충해로 인한 상품가치의 하락으로 현재 수요를 충족시키지 못하고 있는 실정이다. 1 16세기부터 씌워진 과실봉지는 초기 병해충을 방지할 목적만으로 사용되어 왔지만, 현 재는 방균과 방충의 효과와 함께 자연현상의 최적화를 위한 차광성, 발수성, 투기성을 조절 하며 과실의 외관까지 영향을 미치는 바, 과실봉지의 기능성 부여를 위해서는 고도의 기술 력이 요구되고 있다 하겠다. 상기한 배에 방균방충처리된 과설봉지를 씌워서 재배하면 농 약 살포횟수를 줄이고 배에 농약이 직접 묻지 않아 배의 농약오염을 예방할 수 있으며, 봉 지 안으로의 해충이나 균의 침투를 원천적으로 봉쇄할 수 있다. 그러나 기존의 황금배용 봉 지는 비록 기타 병충해 피해를 방지하는 효과는 있었으나, 동녹을 억제하는 효력이 다소 미 흡하였다. 과피의 비정상적인 코르크화로 인해 발생하는 동녹은 과피의 물리적 할렬과 생리적 장 해에 의해 발생하는 것으로 알려져 있다(永澤 1940). 과실이 비대해짐에 따라 과피의 기공 (과점)이 할렬하면서 코르크화가 진행되는데 그 발생정도나 시기는 배의 품종에 따라 다르 나 일반적으로 코르크화는 기상조건, 특히 습도와 밀접한 관련이 있다고 알려져 있다 황금 배의 재배에 봉지를 적용하면 일반적으로 과피의 코르크화가 억제되는데 그러한 이유는 다 음과 같이 설명할 수 있다. 과실은 하루를 주기로 하여 수축과 팽창을 반복하면서 비대화하 는데 이러한 현상은 과실 내의 수분 조건에 따르는 것으로, 봉지재배의 경우 무대재배보다 단기간에 변화되는 습도의 범위가 좁아 급변을 방지하기에 과점의 할렬이 완화될 수 있다. 즉, 봉지를 씌웅으로서 봉지 내의 대기 환경이 외기보다 안정적으로 유지되고 직사광선이나 농약 및 마찰로부터 과실을 보호해 주기에 동녹이 어느 정도 방지될 수 있는 것이다. 그러나 기존의 황금배봉지는 동녹의 정도를 완화시킬 뿐 완전히 방지할 수 없었으며, 봉지를 적 용한 재배조건에서의 동녹발생 기구를 정확히 이해하지 못했었기에 효과적으로 봉지의 기능 을 개선하는 것이 불가능하였다. 과설의 미려도는 과실의 맛과 함께 그 가치를 결정짓는 중요한 물성으로서 우리나라 황 금배 재배환경과 특성에 알맞은 배봉지의 제작이 선결될 때, 배 품질의 향상, 안정된 공급이 가능하게 될 것이며 아울러 농가의 수업증대와 수출 경쟁력 강화가 이루어질 수 있을 것으로 판단된다. 이러한 측면에서 황금배 재배농가가 당면한 동녹발생의 문제점을 신속한 해결 을 위한 새로운 기능성 국산 황금배 봉지의 개발이 절실히 요구되고 있다. 위와 같은 문제를 해결하기 위하여 본 연구에서는 과실봉지의 종류간에 동녹발생 정도 가 상이한 점에 예의 주시하여 다양한 봉지의 적용실험을 통해 다음과 같은 결과를 얻었다. 황금배의 동녹 발생 정도는 배봉지의 발수성과 투기 및 투습도에 의해 크게 영향받는다. 상기한 바와 같이 과점의 코르크화로 인해 동녹이 발생된다고 할 때, 봉지 내의 습기 및 웅결수의 양은 황금배의 동녹에 중대한 영향을 미친다. 태양광이 내려찍는 낮 시간동안 황 금배는 증산작용을 하며 습기를 배출하는데 봉지 내의 온도가 높은 낮 시간 동안 수분이 습기로 존재하지만 기온이 급격히 떨어지는 일몰 이후에는 상대습도가 높아짐에 따라 결로 현상으로 인해 응결수가 된다. 이때 응결수와 접촉한 과피는 건조한 상태보다 세균의 침입 이 용이할 뿐만 아니라 기공(과점)의 호홉에 지장이 초래됨에 따라 과점의 할렬이 더욱 조 장되어 코르크화를 유발하고 결과적으로 동녹이 발생한다고 판단된다. 따라서 만일에 봉지 의 투기, 투습도가 양호하여 봉지 내의 과다한 수분이 충분히 배출될 수 있었다면, 수분의 응결을 피하고 동녹을 완화시킬 수 있을 것이라 판단되었다.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.420-430
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• 2005

As the pine wilt disease spread rapidly over Korea in recent, aerial pesticide spraying to the infected pine stands increased abruptly. The increasing aerial pesticide application for control of the disease would result in disturbance of soil ecosystem in pine stands. This study was conducted to assess the disturbance, using field experiment in pine stands of Hongleong experimental forests in Seoul with BACI experimental design with three sprayed plots and three unsprayed plots of $25m^2$. We sprayed fenitrothion of 0.0335 kg a.i./ha over each of the sprayed plots, being the same as the pesticide residues of litters after aerial spraying. The pesticide had been applied on 4 June, 11 June, and 29 June in 2002, comparable with the dates of the aerial spraying in the previous year in Busan. We monitored population of soil organisms including arthropods, fungi, bacteria, and actinomycetes at two sampling days before pesticide application, at two sampling days during the application season, and at three sampling days after last application for two months since late May in 2002. The pesticide applications did not make any significant effect on the population of arthropods, fungi, bacteria, and actinomycetes in soils and on the structure of soil organism community, showing low probability of significant effects of the aerial pesticide application on soil organisms in pine stands.

• Food Science and Industry
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• v.55 no.2
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• pp.154-165
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• 2022

Humans have been breeding the mulberry silkworm for the long period of time to obtain silk fabric and nutrient-rich pupae. Currently, silkworm larvae, pupae, and silk-Fibroin hydrolysates are registered as food raw materials, while silkworm feces and Bombyx batryticatus are registered as Korean traditional medicines. Among sericulture products, individually recognized health functional food ingredients include silk-protein acid-hydrolysates for immunity enhancement, Fibroin-hydrolysates for memory improvement, and freeze-dried 5^th instar and 3^rd-day-silkworm powder for lowering-blood sugar. Recently, HongJam produced by steaming and freeze-drying mature silkworms were reported to have various health-promoting effects such as preventing the onset of Alzheimer's disease and Parkinson's disease, enhancing gastro-intestinal functions, improving skin-whitening and hair growth, and extending healthspan. By consuming silkworm products with various health-promoting effects, it is possible to increase the healthspan of human beings, thereby reducing personal and national medical expenses, resulting in increasing the individual's happiness.

• The Korean Journal of Pesticide Science
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• v.18 no.2
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• pp.79-87
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• 2014

Pyriofenone is an aryl phenyl ketone fungicide that is newly registered in Korea in 2013 to control powdery mildew on food. The objective of this study was to develop reliable and sensitive analytical method for determination of pyriofenone residue in agricultural products for ensuring the food safety. The pyriofenone residues in all samples(Korean melon, pepper, potato, mandarin, soybean, and hulled rice) were extracted with acetonitrile, partitioned with dichloromethane, and then purified with a silica cartridge. The purified samples were analyzed by HPLC-UVD and confirmed with LC-MS. The linear range of pyriofenone was 0.05~5 mg/kg with the correlation coefficient ($r^2$) > 0.999. Average recoveries of pyriofenone ranged from 72.8% to 99.5% at the spiked level of 0.05 and 0.5 mg/kg, while the relative standard deviation was 2.3%~6.4%. In addition, the limit of detection and limit of quantification were 0.01 and 0.05 mg/kg, respectively. The results revealed that the developed and validated analytical method was suitable for pyriofenone determination in agricultural products.

• Korean Journal of Ecology and Environment
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• v.39 no.3 s.117
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• pp.285-295
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• 2006

Korean water quality standards for the protection of agricultural water uses were originally derived based on management of public water resource. They were not prepared to protect crop plants from contaminants, and therefore required water parameters in agricultural uses were excluded in current water quality standards. Korean water standards in river and lake have five levels, and level IV is correspondent to agricultural water uses. Currently, there is no Korean guidelines to protect crop plants from contaminants contained in agricultural water. In Canada, agricultural water guidelines are provided to protect crops from contaminants. In this study, agricultural water quality standards in Korea were compared with them in developed countries to evaluate the adequacy of Korean water quality standards for the protection of agricultural water uses. Additional water quality parameters in agricultural uses were also proposed. Suggested parameters include electric conductivity, sodium, chloride, boron, copper, iron, zinc, and microbiological quality, They are the required parameters to protect crop plants as well as human health. Current water quality standards in agricultural uses was not considered to be appropriate in terms of crop protection. Additional water parameters should be included in agricultural water quality standards.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.435-445
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• 2008

Due to internal feeding behavior, the oriental tobacco budworm, Helicoverpa assulta ($Guen\acute{e}e$), infesting hot pepper has been regarded to be effectively controlled by targeting egg and neonate larval stages just before entering the fruits. This study aimed to develop an efficient biological control method focusing on these susceptible stages of H. assulta. An egg parasitoid wasp, Trichogramma evanescens Westwood, was confirmed to parasitize the eggs of H. assulta. A mixture of Gram-positive soil bacterium, Bacillus thuringiensis subsp. kurstaki, and Gram-negative entomopathogenic bacterium, Xenorhabdus nematophila ANU101, could effectively kill neonate larvae of H. assulta. A sex pheromone trap monitored the occurrence of field H. assulta adults. The microbial insecticide mixture was proved to give no detrimental effects on immature development and adult survival of the wasp by both feeding and contact toxicity tests. A combined treatment of egg parasitoid and microbial pesticide was applied to hot pepper fields infested by H. assulta. The mixture treatment of both biological control agents significantly decreased the fruit damage, which was comparable to the chemical insecticide treatment, though either single biological control agent did not show any significant control efficacy. This study also provides morphological and genetic characters of T. evanescens.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.204-208
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• 2012

Water repellency which affects infiltration, evaporation, erosion and other water transfer mechanisms through soil has been observed under several natural conditions. Water repellency is thought to be caused by hydrophobic organic compounds, which are present as coatings on soil particles or as an interstitial matter between soil particles. This study was conducted to evaluate the characteristics of the water repellent soil and transport characteristics of trace elements within this soil. Capillary height of the water repellent soil was measured. Batch and column studies were accompanied to identify sorption and transport mechanism of trace elements such as $Cu^{2+}$, $Mn^{2+}$, $Fe^{2+}$, $Zn^{2+}$ and $Mo^{5+}$. Difference of sorption capacity between common and repellent soils was observed depended on the degree of repellency. In the column study, the desorption of trace elements and the spatial concentration distribution as a function of time were evaluated. The capillary height was in the repellency order of 0% > 15% > 40% > 70% > 100%. No water was absorbed in soil indicating >70% repellency. Using trace elements, $Fe^{2+}$ and $Mo^{5+}$ showed higher sorption capacity in the repellent soil than in non-repellent soil. The sorption performance of $Fe^{2+}$ was found to be in the repellency order of 40% > 15% > 0%. Our results found that transfer of $Mo^{5+}$ had similar sorption tendency in soils having 0%, 15% and 40% repellency at the beginning, however, the higher desorption capacity was observed as time passes in the repellent soil compared to in non-repellent soils.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.227-234
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• 2019

An analytical method was developed for the determination of oxytetracycline in agricultural products using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method by liquid chromatography-tandem mass spectrometry (LC-MS/MS). After the samples were extracted with methanol, the extracts were adjusted to pH 4 by formic acid and sodium chloride was added to remove water. Dispersive solid phase extraction (d-SPE) cleanup was carried out using $MgSO_4$ (anhydrous magnesium sulfate), PSA (primary secondary amine), $C_{18}$ (octadecyl) and GCB (graphitized carbon black). The analytes were quantified and confirmed with LC-MS/MS using ESI (electrospray ionization) in positive ion MRM (multiple reaction monitoring) mode. The matrix-matched calibration curves were constructed using six levels ($0.001{\sim}0.25{\mu}g/mL$) and coefficient of determination ($r^2$) was above 0.99. Recovery results at three concentrations (LOQ, $10{\times}LOQ$, and $50{\times}LOQ$, n=5) were from 80.0 to 108.2% with relative standard deviations (RSDs) less than of 11.4%. For inter-laboratory validation, the average recovery was in the range of 83.5~103.2% and the coefficient of variation (CV) was below 14.1%. All results satisfied the criteria ranges requested in the Codex guidelines (CAC/GL 40-1993, 2003) and the Food Safety Evaluation Department guidelines (2016). The proposed analytical method was accurate, effective and sensitive for oxytetracycline determination in agricultural commodities. This study could be useful for safety management of oxytetracycline residues in agricultural products.