• Korean journal of applied entomology
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• v.39 no.3
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• pp.199-205
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• 2000

The field control efficacy of entomopathogenic nematode, Steinernema carpocapsae Weiser, was evaluated on the beet armyworm, Spodoptera exigua (Hiibner). The insect pest has been known to be a defoliator at the aerial part of the crop and difficult to be controlled effectively with most commercial chemical insecticides due to its insecticide resistance. To overcome the susceptibility of the nematodes to desiccation when they were applied by leaf spray in field condition, we screened several commercial antidesiccants (alkyl glucoside, CMC, glycerol, Keltrol-F, Kunipia-G, and Laponite LXG) optimal for survival of the nematodes. Keltrol-F (0.1 %) was selected as a candidate supplement for field application of the nematodes. Leaf spray of the nematodes at 5,000 infective juveniles/ml of distilled water containing 0.1 % Keltrol-F resulted in 87.7% control efficacy on the 3rd instar larvae of Sp. exigua.

• Korean Journal of Organic Agriculture
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• v.17 no.2
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• pp.211-226
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• 2009

This experiment was conducted to investigate the effect of plant extracts, Chrysanthimum cinerariefolium and Melia azedarach to natural enemies and management of two spotted spider mite, Tetranychus urticae in organic strawberry fields in Jeonnam area. Plant extracts were highly toxic against Phytoseiulus persimilis, but low against Orius laevigatus. In the residual effect against Phytoseiulus persimilis, C. cinerariefolium showed lower level than M. azedarach which safe at least 1 day after spray. Emergence rates of parasitoids were about 40% at seven days after spray. Eretmocerus eremicus has very low emergence rate in treatment of M. azedarach, so it should release after spray of M. azedarach. To control of T. urticae C. cinerariefolium (CC) sprayed first and then sprayed C. cinerariefolium or M. azedarach (MA) for two and three times at a week interval. In the treatment of CC+MA and CC+CC+MA, the density of T. urticae was inhibited by 15th day but increased afterward. In CC+MA+CC, that of T. urticae inhibit from 8 days but also increased after I5th day. In case of spray M. azedarach (MA) first, the treatment of MA+CC, MA+MA+CC, MA+CC+MA suppressed T. urticae from the first day so the densy of T. urticae maintained low level to 30 days after spray. It suggested that M. azedarach should spray first and then alternative spray. When C. cinerariefolium sprayed before and behind to release of P. persimilis, the density of P. persimilis maintained unchanged but could not suppress T. urticae after 8 days which T. urticae increase time. When M. azedarach sprayed, the density of T. urticae rapidly decreased. It was accompanied with P. persimilis so T. urticae did not occur at 8 days after treatment.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.160-170
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• 2011

Commercial formulation of fungicides was studied in vitro for sensitivity against Typhula species causal agents of Typhula blight. Efficacies of fungicides application, spray volume, nozzle types and fungicides applied time (early fall and late fall) were evaluated for their influence on the chemical control of Typhula blight of turfgrass during the winter season in Wisconsin. All fungicides effectively reduced the mycelial growth of eight isolates of Typhula spp. in vitro on potato dextrose agar (PDA) media. For inhibitory effects on mycelial growth of eight isolates, propiconazole was the most effective at $1.0{\mu}g$ active ingredient (a.i) / ml of PDA. Typhula incarnata two isolates were significantly more sensitive to all fungicides of PDA than six isolates of three varieties of T. ishikariensis. For 2 years in field experiment, unsprayed control has significantly more disease severity than seven fungicides were applied to field plots at two locations. Propiconazole was the most effective for controlling Typhula blight, at two locations in both years. The level of disease control was not dependent on fungicides spray volume or nozzle types at two locations. The disease damage treated with triadimefon applied time (early fall and late fall) was not significantly different at two location for two years.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.2
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• pp.32-35
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• 2005

밭고랑 옆의 해가림시설 지주목에 파이프라인을 설치하고 방제장치를 탑재한 주행장치가 자동으로 파이프를 추적하면서 농약을 살포 할 수 있는 방제기를 개발하여 인삼재배포장에서 성능시험을 실시하였다. 그 결과를 요약하면다음과 같다. 가. 인삼재배용 방제기의 주행장치는 동력원으로 축전지를 사용하는 DC모터에 의한 4륜 구동형으로 제작하였고, 방제장치는 수직 붐노즐 방식으로 쌍선형 노즐을 좌우에 3개씩 부착하고 살포각도를 조절할 수 있도록 제작하였으며, 인력으로 골간 이동시키는 방식이다 나. 성능시험결과 주행속도는 0.3m/s이고, 장애물이나 요철부의 통과 가능높이는 4cm였고, 작업성능은 38분/10a로 나타났다. 다. 방제성능은 피복면적비를 측정한 결과 인삼 잎 앞면은 100%, 뒷면은 40%이상으로 분무입자의 부착률이 양호한 것으로 나타났다.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2002.10a
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• pp.163-163
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• 2002

국내에서 사용중인 농약에 대한 농민의 농약 노출량 및 양상을 조사하고자 내분비계 장애 물질로 추정되는 Mancozeb의 살포 시 작업자의 피부 노출량 및 호흡 노출량 측정을 감귤농장에서 실시하였다. 피부노출 측정은 Patch법(50$\textrm{cm}^2$)을 사용하였고 손 노출은 순면장갑을 사용하였다. 호흡노출은 XAD-2 resin 흡착제와 Personal air monitor(2L/min)를 이용, 측정하였다. Mancozeb 분석은 CS$_2$법을 이용하였고 patch, resin, 장갑, 마스크, 소변에서 Mancozeb의 회수율 및 포장회수율 모두 90%이상이었다. 감귤 재배시 Mancozeb 사용에 따른 피부노출량은 여자가 약 1800mg/hr, 남자는 약 1300mg/hr 이었고 주로 배, 등, 상박 그리고 허벅지에 노출량이 많았다. 호흡노출은 관찰되지 않았고 소변에서도 Mancozeb는 관찰되지 않았다. 위해성 평가를 위해 PDE, AQE 및 MOS를 구하였으며 MOS는 Severn의 공식을 이용하였다. MOS는 여자가 0.37, 남자가 0.58이었다.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.111-120
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• 2009

This paper presents a fundamental findings of the functional and structural performance of the porous asphalt concrete coated with MMA resin. To evaluate the structural performance, cantabro, wheel tracking, moisture sensitivity and indirect tensile fatigue tests are performed. The tests results show that the cantabro loss is reduced three times and fatigue resistance is significantly increased after the specimens are coated with MMA resin. However there are little changes in the rutting and moisture damage resistances before and after the coating. Air voids, permeability and BPT(British Pendulum Test) tests are conducted to study the functional performance. It is observed form the tests that the air voids and permeability are slightly decreased after the coating. However, the changes in the air voids and permeability are negligible. The skid resistance of the coated specimens is lower than reference specimens. However, the skid resistance is maintained beyond the level of the reference specimens when silica sands are chipped on top of the coated surface.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.813-819
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• 2006

Skid Resistance is a index to represent the friction between tire and road surface, which influences driving safety. Skid resistance varies with the conditions of tire, abrasion of road surface, vehicle speed, drying, wet and freezing condition of road surfaces. Especially, freezing occurs when temperature drops below $0^{\circ}C$ followed by snow or rain causes decrease of skid resistance. To recover the decreased skid resistance deicing work is applied. As a results of deicing works, freezing condition is changed into wet condition. However the wet road surfaces containing the remaining deicings agents may not show the skid resistance of normal wet condition. In this study, skid resistances in the condition of freezing, deicing process and deicing agents remained after snow-removal are evaluated. The test results, skid resistance recover quickly when Pre-wetted salt spreading and NaCl was used as deicing method. Skid resistance of Deicing agents remained on the road surface showed that concrete is higher than asphalt. superior effect. Recovery rate of skid resistance by comparison wet condition is 54~80%.

• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.271-279
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• 2016

To evaluate exposure characteristics of the insecticide imidacloprid to apple orchard workers during treatment on orchard fields and evaluate its potential risk using a whole body dosimetry (WBD) method, 1,000-time diluted acephate+imidacloprid 25(20+5)% solutions were sprayed on 10 apple orchard fields in Cheongju with a speed sprayer at a rate of 3,000 L/ha/person, after put on clothes such as inner/outer clothes, personal air pump with a IOM sampler, nitrile glove and mask. Exposure test included mixing, loading and application steps. The test pesticide imidacloprid residues in the collected samples were analyzed with a HPLC-DAD. Recoveries ranged from 81.5 to 108.6% for analytical method validation and from 73.8 to 86.7% for field recovery. Total exposed amounts to mixer/loader and applicator were found to be 0.0014-0.0279% of total applied active ingredient of imidacloprid. Glove exposure of both mixer/loader and applicator was higher than the other parts. Margins of safety of mixer/loader and applicator were calculated to be 97-355 and 46-196, respectively, indicating that exposure risk of imidacloprid to apple orchard workers by spraying with a speed sprayer was very low.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.3
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• pp.172-177
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• 1982

This experiment was conducted to evaluate the broadcast and band applications of phosphate fertilizer and the application amounts of fertilizer during the soybean-barley cropping periods from 1976 to 1979 on the Sam-gag sand loam of a newly reclaimed hilly land. 1. The broadcast application was superior to band in view of yields for both soybean and barley. The yield was the highest in the broadcast application with the amount 38 kg $P_2O_5$ per 10a of fused phosphate which was calculated from soil testing at the first crop period and thereafter additional 6 kg at every crop period. 2. According to the quadratic relationship between yield and the available phosphate in soil, the maximum soybean Yield, 322 kg per 10a obtained at 220 ppm of available phosphate under broadcast and 259 kg per 10a at 200ppm under band. 3. By broadcast application of phosphorus, root weight was higher and horizontal root expansion was much better than by band application.

• Korean journal of applied entomology
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• v.40 no.4
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• pp.315-319
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• 2001

Damage and control of cutworms in the tobacco fields were studied during 1998~2000. It was estimated by surveys on cutworm damage that control measures should be taken for 9.0~10.2% of the surveyed fields. However, most of the interviewed growers broadcasted granule insecticides before or during tobacco plant transplantation. The damaging period and cutworm behavior suggested that the most effective control method would be the application of emulsifiable concentrate or wettable powder around the base of tobacco plants in the fields showing more than ca. 2% of damage ratio.