• International Journal of Highway Engineering
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• v.7 no.2 s.24
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• pp.45-55
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• 2005

It is known that the Q/C(Quality Control) in the early age of portland cement concrete(PCC) pavement gives a huge effect on long term pavement performance. Thus, many studies regarding the construction of PCC pavement have focused on how to assure construction quality at the early age stage. Curing is one of the most important factor in Q/C of PCC pavement. Membrane curing that protects the evaporation of moisture by placing an impermeable layer on the slab surface is the most common practice for curing the PCC pavement. In order to improve the membrane curing practice, the rate of curing compound should be optimized. However, the optimum rate of curing compound considering Korean weather and environmental conditions has not been specified in the pavement construction specifications. In this study, a proper application rate was recommended in terms of minimizing evaporation with several full-scale tests where various rates of curing compound have been applied. Four test sites on the expressway were enlisted during the summer of 2002 and 2003. Application rates tested were in the range of $0. The rate of evaporation, the temperature pattern of the slab and the pulse velocity of concrete surface have been monitored at each test construction. The result from this study showed that the rate of current construction was approximately $160ml/m^2$ and that approximately $400ml/m^2$ of curing application was recommended as the proper rate for minimizing the moisture evaporation.

• Agrochemical news magazine
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• v.24 no.5 s.188
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• pp.18-22
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• 2003

• Korean journal of applied entomology
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• v.29 no.4
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• pp.252-256
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• 1990

Viral insecticides were formulated with Spodoptera litura nuclear polyhedrosis virus and different U.V. protectants based on white carbon, molasses, and white carbon and molasses mixture to use as microbial control agents. Effect of rainfall on the attachment of formulated viruses to leaves was no different between the treated and the non-treated experiment. Persistence of the formulations was lated 5 days on the surface-sprayed leaves and 12 days on the under-sprayed leaves which was showing 60% mortality. Total mortality of the viral insecticides was more than 97% with no differences among them. Field evaluation of three viral insecticides in soybean field was very successful then carried out in Chinju, a southern part of Korea. Mortality by the formulation in the field during 14 days was more than 93%, but the formulations contained molasses showed phytotoxicity on soybean leaves. Spray effect of the viral insecticides was begun to appear from 7 days later than that of chemical insecticide.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.150.1-150
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• 2003

열무의 안전한 생산을 위한 생산단계에서의 각 농약 잔류량 변화 추이와 최종 소비단계에서의 농산물 안전성 평가자료로 활용하기 위하여 실제 시험포장에 열무를 파종한 후 수확 10일 전에 4 종(diazinon, endosulfan, cypermethrin, cyhalothrin)의 살충제를 각 성분별로 안전사용 기준에 따라 기준량 및 배량의 처리구에 직접 살포하여 열무의 포장상태에서의 잔류량 감소(생물학적 반감기) 변화를 조사하였다. 각 농약별로 2 수준 농도의 표준물질을 첨가하여 실험한 결과 평균회수율은 diazinon 98.7∼99.9%, endosulfan 97.6∼98.5%, cypermethrin 98.3∼99.6%, cyhalothrin 98.4∼99.1%이였고, 검출한계는 diazinon 및 cypermethrin은 0.04 mg/kg, endosulfan은 0.012 mg/kg, cyhalothrin은 0.01 mg/kg 이었다. 약제 살포 후 분해속도가 빠른 성분은 diazinon ＞ endosulfan ＞ cypermethrin ＞cyhalothrin 순이었다. 작물체(열무)내에서 시간의 경과에 따른 잔류량의 변화를 1차 반응으로 표현하여 농약 4종의 살포농도별 생물학적 반감기를 산출한 결과, 기준량 살포의 경우 diazinon 0.9일, endosulfan 2.0일, cypermethrin 2.2일, cyhalothrin 2.5일 그리고 배량 살포의 경우에는 diazinon 1.1일, endosulfan 2.0일, cypermethrin 2.1일, cyhalothrin 2.2일로 나타났다. 안전한 농산물 생산을 위한 열무 중 약제 살포 후 수확일은 잔류허용기준(MRL)을 적용시킬 경우 기준량으로 볼 때 diazinon은 6일 후, endosulfan은 10일 후에 수확하는 것이 바람직한 것으로 나타났으며 합성 피레스로이드계인 cypermethrin과 cyhalothrin은 농약살포 후 2 시간 후에 농약 잔류량이 잔류허용기준 미만으로 나타났다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.83-89
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• 2003

붐방제기는 분무관에 일정한 간격으로 노즐이 설치되어 있으며 목표물 바로 위에서 농약을 직접 살포할 수 있다. 따라서 비산의 위험성이 적고 작업폭이 넓기 때문에 포장능률도 높은 장점이 있다. 또한 방제작업에 영향을 미치는 방제속도, 살포폭, 노즐 배출량, 노즐 압력 등을 최적으로 유지할 수 있는 자동제어 시스템을 채택할 수 있어 최적량의 농약을 균일하고 유효하게 살포할 수 있다. (중략)

• Korean Journal of Organic Agriculture
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• v.22 no.2
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• pp.347-357
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• 2014

This study was conducted to evaluate the control effect of sodium dichloroisocyanurate (NaDCC) for Venturia nashicola on Niitaka pear during flowering period. As a nontoxic disinfectant, sodium dichloroisocyanurate is widely used in the field of hygiene and disease prevention, medical treatment, aquiculture as well as plant protection. NaDCC was sprayed on the pear tree inoculated with conidia ($4.5{\times}10^5spores/mL$) of Venturia nashicola and as a result the incidence of pear scab was 23.8% in 750mg/L and 26.2% in 1,000mg/L compare to the 51.6% incidence in untreated tree. No damage in the pollen of pear flower was detected with NaDCC treatments in the full bloom period for six pear cultivar including Wonwhang. A NaDCC single treatment in the early bloom of Niitaka pear showed more than 98% of fertilization rate. Furthermore, there was no incidence of Venturia nashicola on Nitaka pear trees treated with NaDCC 4 times during their growth period.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.370-375
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• 2002

동일한 포장내에서도 위치별로 토성과 비옥도에 따른 수확량에 서로 차이가 있으나 현재는 비료와 농약 등을 전체 포장에 대하여 동일한 기준으로 다량 살포하고 있어 농자재의 과다투입에 의한 환경오염이 초래되고 있다. 이러한 불합리한 영농을 배제하고 친환경적인 정밀농업을 구현하기 위해서는 작물재배 환경에 따른 포장 각 지점의 수확량을 정확히 계측하여, 수확량과 토성이나 토양의 비옥도, 생육상태, 균평도 등과 같은 포장정보들 사이의 상관관계를 분석하여 비료 농약의 적절한 투입량을 결정하는 것이 필요하다. (중략)

• Journal of Applied Biological Chemistry
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• v.57 no.1
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• pp.73-81
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• 2014

The present study was carried out to assess exposure and risk to thiophanate-methyl wettable powder for agricultural worker during mixing/loading and application with power sprayer in green pepper, cucumber and apple fields. Dermal exposure was measured with patches, gloves, socks and masks, while inhalation exposure was evaluated with personal air pump and solid sorbent. Those methods were full validated before experiment. During mixing/loading, dermal exposure amount in green pepper, cucumber and apple fields was $24.0{\pm}6.7$, $4.5{\pm}1.5$ and $18.5{\pm}0.6mg$, corresponding to mean 0.007, 0.001 and 0.005% of prepared active ingredient, respectively. The major exposed part for mixer/loader was hands (78-92%). Dermal exposure amount for applicator in green pepper, cucumber and apple fields was $84.9{\pm}14.0$, $34.0{\pm}20.8$ and $30.7{\pm}9.1mg$, corresponding to mean 0.024, 0.016 and 0.013% of applied active ingredient, respectively. The main body parts of exposure in apple field were hands, while thighs and shins in other fields. Inhalation exposure amount in green pepper, cucumber and apple fields was $1.5{\pm}2.2$, $52.7{\pm}48.9$ and $4.0{\pm}4.9{\mu}g$ during mixing/loading and $0.2{\pm}0.1$, $23.2{\pm}12.4$ and $0.4{\pm}0.6{\mu}g$ for applicator, respectively. These results were suggested that main factors affecting dermal exposure were contact frequency to the plants, foliage density, hygienic behavior, work type, and working environment, while inhalation exposure was affected mainly by working environment, especially wind. In risk assessment, margin of safety for thiophanate-methyl in all cases was over 1. However, during application in green pepper field, margin of safety was close to 1.

• Research in Plant Disease
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• v.26 no.4
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• pp.229-238
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• 2020

Field validation of PBcast, an infection risk model for Phytophthora blight of pepper, was conducted through a designed field experiment in 2012 and 2013. Conduciveness of weather conditions at 26 locations in Korea in 2014-2017 was also evaluated using PBcast. The PBcast estimated daily infection risk (IR) of Phytophthora capsici based on weather and soil texture data. In the designed filed experiment, four treatments including routine sprays at 7-day intervals (RTN7), forecast-based sprays when IR reached 200 (IR200) and 224 (IR224), and no spray (CTRL) were compared in terms of disease incidence and number of sprays recommended for disease control. In 2012, IR had reached over 200 twice, but never reached 224. In 2013, IR had reached over 200 three times and once higher than 224. The RTN7 plots were sprayed 17 and 18 times in 2012 and 2013, respectively. Weather conditions throughout the country were generally conducive for Phytophthora blight and 3-4 times of fungicide sprays would have been reduced if the PBcast forecast information was adopted in the decision-making for fungicide sprays. In conclusion, the PBcast forecast would be useful to reduce fungicide applications without losing the disease control efficacy to protect pepper crop from Phytophthora blight.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.373-381
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• 1997

In order to investigate the drift of pesticides sprayed on Chinese cabbage, 7 pesticides chlorpyrifos, EPN, pirimiphos-methyl, phenthoate, tetradifon, dicofol and bifenthrin were applied in two sets of field tests. The pesticide residues were quantified bar multiple-residue analysis, in which the recovery rate was 78${\sim}$92% and standard deviation was ${\pm}0.683{\sim}52%$. It was found that most of the tested pesticides were spread by drift to neighbouring area and brought about the contamination of the unsprayed crops. The extent of drift varied depending upon the pesticide, distance and wind direction. The mean residue levels on unsprayed crops were 0.66% at 3 meter distance, 0.10% at 6 m distance and 0.05% at 9 m distance from the applied area and the maximum level was 1.83% of the residue on sprayed crops.