• Korean Journal of Environmental Agriculture
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• v.5 no.2
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• pp.119-129
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• 1986

Disappearence of the trichlorfon (Dipterex) in the forest, following aerial to control Agelastica coerulea B., were studied by sampling deposits on slide glasses, soils, water, and leaves, and analysing with a gas chromatograph equipped with an electron capture detector. By analysing the amount remained on slide glasses, it was shown that the pesticide was adequately sprayed and nearly all deposit was lost in a day. The amount deposited under the tree was about 1/100 of the amount at an exposed site. Concentration of trichlorfon in creek water was 10 to 100 times as high as the acute toxic level to zooplankton for 6 to 24 hours, The rain could recontaminate the stream water up to the toxic level. Loss rate of trichlorfon from soils showed variations by sampling sites and was generally slower than from slide glasses. Amount deposited on leaves were less than the calculated or expected amount. The loss from leaves were similar to that from soil.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.403-413
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• 2008

This study was conducted to select excellent tank mix combinations of pesticides for aerial application by manned helicopter. Among 209 pesticide combinations of 3-way tank-mixing for aerial application, a total of 93 recommendable combinations including tricyclazole SC+validamycin-A SL+imidacloprid SL were finally selected for the simultaneous control of key pests on paddy rice such as blast, sheath blight, brown planthopper and moth. The selected combinations were not phytotoxic to rice plants and nearby non-target crops, and excellent in physicochemical properties of ultra low volume (ULV) spray solutions. The efficacies on sheath blight, brown planthoppers and white-backed planthoppers of pesticides sprayed by aerial application were similar to those of pesticides by conventional spraying. Total cost of aerial application in paddy rice was very economical as one fourth level of that of conventional spraying.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.116-121
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• 2000

Photosensitizing activities of some selected photosensitizers (PS) on the artificial diminution of pesticide residues on red pepper were investigated. Red peppers were sprayed 4 times with the three fungicides, dithianon, triflumizole, and triforine, according to the conventional method, followed by the application of photosensitizers once. Recoveries for the analyses of the pesticide residues were high $(90.7{\sim}98.5%)$ except for dithianon $(76.6{\sim}78.3%)$. In case of dithianon, after 1 day of the application of PS-1 (10 ppm), the residual amount was 76% of that of the control. For triflumizole, the residual amount after 3 days of the application of PS-4 (50 ppm) accounted for 48% of that of the control. In case of triforine, the residual amount after 1 day of the application of PS-3 (100 ppm) was 55% of that of the control. The results indicated that the photosensitizing activities of photosensitizers varied with chemicals and the matrices where pesticide residues are remaining.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.285-290
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• 1984

The effects of retardants B995 and CCC on the growth and yield of soybean cultivar, kwanggyo, were investigated. The 3 application times(4th, 5th and 6th trifoliate leaf stage) combined with 4 concentrations (500, 1000, 2000 and 3000 ppm) were treated, and the retardant solutions were sprayed on the foliage. Only stem length in retardants, rate of podding in application times, and, in concentrations, stem length, number of branch, number of pod per plant and grain yield, were significant. In the inhibition of stem elongation, B995 was more effective than CCC, and rate of podding was the highest in the 4th leaf-spraying. The highest concentration, 3000 ppm, was the most effective in the inhibition of stem elongation and in the increase of number of branch and pod, rate of podding, and in yield. The number of node of mainstem, dry stem weight, chlorophyll and 100 grain weight were not significant with any treat. Yield had positively correlated with number of branch and pod, and rate of podding but negatively with stem length. The retardants was thought to be considerably conducive to the increase of yield.

• Korean journal of applied entomology
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• v.15 no.2 s.27
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• pp.57-60
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• 1976

Experiments were carried out to determine the effectiveness of a new systemic fungicide EL-291 (5-Methyl-1, 2,4-triazolo (3,4-b) benzothiazole) for the control of rice blast disease in greenhouse and paddy field. The efficiency of EL-291 was much greater when applied before inoculation than when applied after inoculation. Kasugamin and Benlate were most effective as eradicants. For control of leaf blast, effectiveness of EL-291 was not significantly different than either Kasugamin or Benlate. However, EL-291 was considered more economical and reliable than either Kasugamin or Benlate. EL-291 required only a single foliar application or a transplant root soak, whereas two applications of the other fungicides were required. EL-191 was also more effective against panicle blast when applied only once, compared with two applications of Kasugamin or Benlate. The highest riceyields were obtained in plots treated with EL-29l.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.3
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• pp.1-12
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• 2000

식물생장조절제(Plant Growth Regulators, PGRs)를 이용한 예초관리 방법이 들잔디 엽색 및 품 질에 미치는 영향을 규명함으로 잔디 적응력 관점에서 적합한 PGR 종류 및 살포수준을 파 악하고자 본 연구를 시작하였다. 실험은 들잔디 생육이 왕성한 시기인 6월(실험 I)과 7월(실험 II) 2회에 걸쳐 각각 다른 장소에서 실시하였다. 공시약제 처리구는 Type I PGR인 amidochlor 3 수준 및 mefluidide 3 수준 과 Type II PGR인 trinexapacethyl 4 수준, 그리고 무처리구를 포함하여 전체 11 처리구였 고, 실험구 배 치는 난괴법 4 반복으로 하였다. 공시한 3종류 PGR 모두 잔디엽색 및 품질에 통계적으로 유의한 차이 가 있었지만, PGR 종류.살포수준 및 생육 상태에 따라 처리효과는 다르게 나타났다. 잔디 엽색 및 품질 은 PGR 살포후 경과기간에 따라 점진적으로 억제되는 경향이었다. 처리 1주후 잔디품질은 대조구에 비 해 큰 차이가 없었지만, 2주에서 4주까지는 PGR 종류 및 살포수준에 따라 유의하게 감소하 여 0.08 ml/ $m^2$ 이상의 trinexapac-ethyl 처리구 및 1.20 ml/$m^2$ 이상의 mefluidide 처리구에서는 가장 크 게 나타났다. 처리 4주부터 대부분 처리구에서 잔디품질이 적정수준 이상으로 회복되기 시작하였다. 본 실험을 통해 잔디관리 수준에서 저관리 잔디지역은 0.08 ml/$m^2$ 수준의 trinexapac-ethyl 처리구가 장기간 생장억제 관점에서 실용성과 경제성 측면에서 들잔디 관리에 효율적인 것으로 판단되었고, 고관리 잔 디지역은 0.04~0.08ml/$m^2$ 수준의 trinexapac-ethyl 처리구 및 0.60~1.20 ml/$m^2$ 수준의 amidochlor 처 리구가 적합 한 것으로 판단되었지만, 계절에 따라 PGR 효과정도가 다르게 나타났다. 따라서, 잔디 관리 시 잔디의 생육상태, 예초 절감 기간, 잔디품질의 기대수준 및 적용할 수 있는 관리수준에 따라 적합한 PGR 종류 선정과 함께 살포시기 및 살포량을 효율적으로 결정하는 것이 필요한 것으로 사료되었다.

• Smart Media Journal
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• v.8 no.4
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• pp.38-45
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• 2019

When there is a spray flow such as from a pesticide nozzle, winds affect the droplet flow of a rotary-wing drone accompanied by a strong wake, with a severe oscillation. Especially, during forwarding flights or when winds come from the side, compare to a simple hovering flight as the droplet is in the effect of aerodynamic drag force, the effect of spraying region becomes even larger. For this reason, the spraying of pesticides using drones may cause a greater risk of scattering or a difference in droplet dispersion between locations, resulting in a decrease in efficiency. Therefore, through proper numerical modeling and its applied simulation, an indication tool is required applicable for the various flight and atmospheric conditions. In this research, we completed both experiment and numerical analysis for the strong downwash from the rotor and flight velocity of the drone by comparing the probability density function of droplet distribution to build a spraying system that can improve the efficiency when spraying droplets in the pesticide spray drone.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.10
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• pp.8-19
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• 2019

In this study, the spray pattern of a centrifugal fertilizer distributor with two shutter holes was analyzed and an effective driving width that satisfies proper spray uniformity was derived. The centrifugal fertilizer distributor was mounted on a tractor with a rated power of 23.7 kW and static and dynamic spray pattern tests were performed according to the standard procedure proposed by the American Society of Agricultural and Biological Engineers Standard ASAE S341.5. The height of the fertilizer distributor was 80 cm from the ground and the PTO (power take-off) shaft speed of the tractor was fixed at 540 rpm. The fertilizer scattered in space was collected using 275 evenly spaced collectors at shutter opening ratios of 25%, 50%, 75%, and 100%. The spray pattern was analyzed via the amount of sprayed fertilizer at each collector location and the coefficient of variation was used as an indicator of spray uniformity. Using the analyzed spray pattern, the effective driving width that satisfied less than 15% of the coefficient of variation was derived for different tractor driving patterns (race track mode, back and forth mode). From the results, spray uniformity increased as the shutter opening ratio decreased. The largest effective driving width was 8 m at a shutter opening ratio of 25% for both driving patterns.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.441-449
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• 1996

This study was conducted to find the changes of growth, seed yield and several characteristics of sesame by leaf spray of boron as a solution which is likely to be lack in the soil. It is carried out at low land developed 5 years ago. The amount of 200l /l0a boron as boric acid is sprayed in each treatment at the 11 node stage of sesame in main stem. The spraying concentrations of boric acid are 0.0, 0.2 and 0.4% in each treatment of the level low plot and the ridge height 15cm plot. The result shows that leaf area is increased in proportion to the concentration of boric acid in each treatment of the level low and the ridge height 15cm, and the degree of increase of each node order is remarkable in lower leaves and is more remarkable in the treatment of level low plot. The effects of leaf spray of boric acid are not only the increase of leaf area but also dry weight, no. of capsule per plant, 1,000 grains weight of capsule setting under middle position. As a result, the amount of seed is increased in 53% in the treatment of level low. The change of major characteristics according to leaf spray of boric acid is generally great in the treatment of level low. Especially the increase of leaf area in the part of upper leaves and low leaves is effective to improve other characteristics.