• Journal of the Korean Data and Information Science Society
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• v.14 no.2
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• pp.201-208
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• 2003

Since no information about the optimum plot sizes on field experiments on the major food crops in Korea is available, present status of plot sizes being used by the research institutes was examined for rice, barley & wheet, soybean, potatoes, red pepper, garlic and onion. The optimum plot sizes in field experiments on these crops were estimated on the basis of soil fertility indices (Smith's regression coefficients) that Chang (1983) reported.

• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.30-36
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• 2024

This study was conducted to determine the optimal working conditions when a recently developed blower-type onion stem cutter is utilized for cutting onion leaves at harvest time. The June 20 leaf cutting treatment group had the highest leaf dryness among the treatment groups (leaf dryness: 66.3%; leaf moisture content: 50.5%); the residual leaf length was 6.7 ± 3.5 cm. It is considered to have the best mechanical leaf cutting performance among the treatment groups because it is included in the optimal range of 4-10 cm. The average working speed of mechanical onion leaf cutting using the stem cutter was 0.17 m·s^-1, which is approximately 3.4 times faster than the average working speed of 0.05 m·s^-1 in the human leaf cutting treatment group. This is expected to save approximately 2.6 hours compared to human labor (based on one person) when working on a 10a area using this machine. In addition, the incidence of damaged bulbs in the machine leaf cutting treatment group was 1.3%, compared to 0.0% in the manual leaf cutting treatment group. This suggests that the mechanical leaf cutting treatment group had a higher average onion bulb decay rate during storage than the manual leaf cutting treatment group. When the storage characteristics of each treatment group were examined, the decay rate by bulb part (leaf connected or root connected) after 8 months of storage was higher in the treatment group with a residual leaf length of less than 5.0 cm after mechanical leaf cutting than in the treatment with a residual leaf length of more than 5.0 cm. This is thought to be due to the fact that treatments with a residual leaf length of less than 5.0 cm are more susceptible to infection by pathogens that cause decay during storage than treatments with a residual leaf length of 5.0 cm or more. Based on the results of this experiment, performance target of the experimental machine (residual leaf length after operation: 5 cm), and existing research on the optimal residual leaf length for onion harvesting, it is recommended to cut onion leaves so that the residual leaf length is 5-10 cm when using the stem cutter.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.695-703
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• 2014

We experimented with the effect of oleic acid and its appropriate concentration to prevent powdery mildew eco-friendly in a cucumber greenhouse cultivation. 'Baekbongdadaki' (Nongwoo Bio. co. Korea) was treated in the plastic greenhouse at Sangmyung University. We treated four levels of concentration of oleic acid, which were 0, 2000, 4000, 6000, and 8000 ppm. There were investigated diseased severity, diseased leaf area, control value, and pesticide injury. The degree of control values by oleic acid treatments was investigated at 3 days after treatment. The recurrence of powdery mildew was checked for 55 days. The day and night temperature in the greenhouse were controlled to 23 and $15^{\circ}C$ respectively. The humidity inside the greenhouse was not controlled to prevent outbreak of the disease. From the experimental results, oleic acid was very efficient to control powdery mildew. 2000 ppm of oleic acid was shown to be the most control efficiency without any pesticide injury. The recommended method to treat it was to spray three times every 3 weeks.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.05a
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• pp.153-157
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• 1998

무등산 수박의 유묘 생산에 있어 적정 배양액 농도를 구명하기 위하여 일본원시균형배양액을 기준으로 하여 NO$_3$-N, K 및 Ca의 농도별 첨가량에 따른 유묘생장반응을 조사하였다. 1. 배양액내 질소농도을 증가시킬수록 초장, 엽면적, 엽수, 엽장, 엽폭이 증가하였으며 생체중과 건물중도 증가하였다. 2. 배양액내 칼륨의 농도를 증가시켰을 경우 수박 유묘의 초장은 200ppm까지는 약간 증가하지만 엽면적, 엽수, 엽장, 생체중 및 건물중은 200ppm이상으로 증가시키면 감소하는 경향이었다. 3. 칼슘처리의 경우 농도의 증가가 생장의 증가를 나타내지는 않았으며 원시균형 배양액의 표준이라 할 수 있는 80ppm처리구의 생장이 양호한 것으로 나타났다. 4. 배양액(일본원시균형배양액 1/2농도)에 N의 농도를 200ppm으로 증가시킬 경우 수박유묘의 엽병내 N, K 및 Mg의 함량이 증가하였지만 P 및 Ca의 증가나 감소의 경향은 보이지 않았다. 5. K의 농도를 100ppm으로 증가시킬 경우 수박유묘의 엽병내 N, K 및 Mg의 함량이 증가하였지만 P 및 Ca의 증가나 감소의 경향은 보이지 않았다. 5. K의 농도를 150ppm으로 증가시킬 경우 수박유묘의 엽병내 N, K 및 Mg의 함량이 증가하였지만 P 및 Ca의 증가나 감소의 경향은 보이지 않았다. 그러나 200ppm이상으로 증가시킬 경우 N과 Mg의 감소가 나타났다. 6. 양액내 Ca의 농도를 증가시킬수록 엽병내 N, K Ca 및 Mg의 농도가 증가하는 반면 P의 경우 거의 변화가 없었으며,N의 경우는 200ppm 이상의 농도에서 감소하는 경향을 나타내었다. Mg의 경우는 150ppm까지는 함량의 변화가 없었지만 200ppm 이상의 처리구에서 급격한 함량증가를 나타내었다.~21.2ml가 흘러나와 배지의 공극이 일정하지 않아 시간당 통과하는 양이 일정하지 않았다고 생각되었다. $\bigcirc$ 펄라이트 : 합섬A(비스코스+레이온)급액천의 유입은 소(1$\times$60cm)에서 21.8ml, 중(2$\times$60cm) 33.5ml, 대(3$\times$60cm) 43.4ml가 통과되었고 합섬(폴리에스텔)에서는 19.0~30.7ml로서 급액천의 규격에 따라 통과되는 차이가 있었다. 배지가 규격화되어 있어 급액천의 규격별로 일정하게 유입되었으며 급액천의 재질이 유입에 영향을 미친 것으로 사료되었다. (2) 급액관과 베드상과의 높이에 따른 유출양 : 급액과 베드상과의 낙차가 클수록 유출이 증가함을 알수 있었으나 합섬C(인견)실험구에서는 낙차가 유출에 영향을 미치지 않았다. (4) 급액된 양액의 EC 및 pH조사 : 급액된 양액의 EC 및 pH에 전혀 변화가 없어 재배 적응에 문제가 없을것으로 사료되었다.이가 가장 이상적인 것으로 생각된다.세포수에 대한 내부세포괴세포(ICM/total cells)가 20~40% 범주에 드는 비율은 처리구가 대조구보다 낮은 결과를 나타냈다. 결론적으로 돼지난포란을 이용하여 체외성숙을 유기할 때 효과적인 cysteamine의 농도는 50$\mu$M이 적당하며, 초기배발달을 유기할 때의 효과적인 cysteamine의 농도는 25~50$\mu$M인 것으로 판단된다.N)A(N)/N을 제시하였다(A(N)=N에 대한 A값). 위의 실험식을 사용하여 헝가리산 Zempleni 시료(15%$S_{XRD}$)의 기본입자분포로부터 %$S_{XRD}$를 계산한

• Korean Journal of Organic Agriculture
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• v.13 no.4
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• pp.413-422
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• 2005

This study was carried out to investigate the effect of different mixture ratios of vermicasts on the growth of leaf beet(Beta vulgaris var. cicla), young radish (Raphanus sativus L), spinach(Spinacia oleracea) and lettuce(Lactuca sativa) The mixture of ratios of vermicast(fermented pig manure with sawdust) and peatmoss were 100%+0%, 60%+40%, 40%+60% and 0%+100%(control), respectively. The bulk density, particle density, pH, electrolytic conductivity, ash, total nitrogen, cation exchange capacity, available phosphorous and exchangeable cations increased significantly compared to those grown in the 100% of peatmoss(control). The significantly higher values of plant length, leaf area, shoot dry weight, root weight, root length and biological yield obtained were $40{\sim}100%$ and 40% of vermicast in leaf beet and lettuce, respectively. The young radish and spinach showed that significantly differences of shoot dry weight, root weight and biological yield in the mixture ratios of vermicast were $40{\sim}60%$ and 40% in young radish and spinach, respectively.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.212-217
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• 2005

This experiment was conducted to investigate the effect of water soluble fertilizer(WSF) and slow release fertilizer(SRF) on the growth of carnation(Dianthus caryophyllus 'Invitation') cultured in C-channel mat irrigation system. Plants grown in $0.8{\~}1.0\;g{\cdot}L^{-1}$ of WSF showed the highest quality, especially on fresh and dry weight of aerial part, leaf number, total leaf area, plant height, and branch number. All plants showed increase of growth rate around 60 days after treatment, although there was a different increase rate. Total leaf area decreased its increase rate after 90 days after treatment. Carnations supplied by WSF showed better growth and quality than SRF, and the optimum concentration range of WSF for pot-carnation was $0.8{\~}1.0\;g{\cdot}L^{-1}$ in C-channel mat irrigation system.

• Journal of Korea Water Resources Association
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• v.47 no.10
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• pp.973-983
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• 2014

This study focused on the selection of appropriate plant species of VFS (vegetative fiter strips) and the assessment of VFS effects for reducing NPS (non-point source) pollution from uplands. The experimental field was constructed with 1 control and 6 treated plots in the upland area of $1,500m^2$ with 5% slope which is located in Gunwi-gun, Gyeongbuk province. Six vegetation including Chufa, Common crabgrass, Barnyard grass, Turf grass, Tall fescue, Kenturky bluegrass, were applied to install VFS systems during the study period from June 2011 to Dec. 2012. The results of this study showed that 6.1~77.8% in runoff and 15.6~90.3% in TS, 49.9~96.6% in T-P, and 6.7~91.1% in T-N were reduced from the VFS treated plots. Generally high reduction effects were observed from TS, T-P, T-N, and SS, while BOD, TOC, and $NO_3^-$ showed low reductions. The best vegetation type was Turf grass showing higher reduction effects of NPS pollutions and having relatively easier maintenance efforts compared to other vegetations selected in this study. Based on these results, VFS technique found to be an effective management practice for reducing agricultural NPS pollutions in Korean upland conditions. Further study needs to be performed through various field experiments with long term monitoring in order to develop a design manual of VFS system for practical applications.

• Journal of Bio-Environment Control
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• v.16 no.1
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• pp.27-31
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• 2007

The experiment has investigated the effects of blending rate of waste rockwool in nursery media on growth of Marygold 'Yellow boy' plug seedlings. A commercial plug medium containing 10% zeolite, 10% vermiculite, 5% perlite, 10% peatmoss and 65% cocopeat was used as the control, and the other media compounded with 10% of zeolite, vermiculite, perlite and peatmoss and 10, 30, and 50% of waste rock-wool. There was not significant difference in germination rate ot Marygold between treatments. Plant height, number of leaves, stem diameter and leaf area were higher in commercial plug medium and compound nursery media containing 50% of waste rockwool than 30 or 10% of waste rockwool. Fresh weight and dry weight of shoot and root increased in the treatment of commercial plug medium and the medium of 50% waste rockwool than 10 and 30% of waste rockwool. These results suggested the possibility of utilization of waste rockwool for medium components of plug seedlings.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.343-350
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• 2016

The aim of this study was to evaluate effects of immature compost on the amount of nutrient content, heavy metal concentration, and application rate that were used for lettuce cultivation. The characteristics of the two composts (Compost A (CA) was immature compost and Compost B (CB) was mature compost) were evaluated upon mixing with commercial soil at 0%, 25%, 50%, and 75% (w/w). The poor chemical characteristics were appeared by use of immature compost as soil amendment; the 50% and 75% rates were weakly acidic at pH 5.39 and 5.50, respectively. The total carbon content at using of 75% of the immature compost and mature compost increased the most to 14.5 and 6.5% and it significantly increased concentrations of the total nitrogen and phosphorus compared to control. As for 75% mature compost rate increased significantly the concentrations of Cu ($128mg\;kg^{-1}$), Zn ($260mg\;kg^{-1}$), Pb ($0.32mg\;kg^{-1}$) and, Cd ($0.48mg\;kg^{-1}$) compared to control, and the highest As concentration increased significantly at 75% and 50% (6.69 and $6.28mg\;kg^{-1}$) including in 25% immature compost as $6.48mg\;kg^{-1}$. However, all of the high compost rates significantly decreased the shoot biomass of lettuce. The immature compost was potentially amended at an application rate of 25% due to a slight salinity and low risk to heavy metal uptake on lettuce growth. This use may be available if the rate is lower than that used in this trial.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.214-219
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• 2013

This study was conducted to examine the effect of LED light quality and treatment time on the growth and flowering in potted plants of Impatiens (Impatiens hawkerihybrid). Plant height of Impatiens was enhanced under Blue light, regardless of treatment time. Root length and stem diameter of Impatiens were enhanced by Red light or Blue light. The number of internodes was not influenced by LED light quality. The number of branches of Impatiens was increased under Blue light, but treatment time did not result in statistically significant differences. Leaf area was increased by all LED lights in Impatiens. The number of flower buds and open flowers was decreased by LED light, but days to flowering were reduced by Red light in Impatiens. Chlorophyll and anthocyanin content were not significantly affected by LED light, but anthocyanin content tended to increase by Blue light for 4 h after sunset. Fresh and dry weights were enhanced by Blue light in Impatiens.