• Microbiology and Biotechnology Letters
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• v.51 no.2
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• pp.203-207
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• 2023

The N₂O-reducing rhizobacterium, Pseudomonas sp. M23, was isolated from maize rhizosphere soil. The maximum N₂O reduction rate of the strain M23 was 15.6 mmol·g-dry cell weight^-1·h^-1. Its N₂O reduction activity was not inhibited by diesel contaminant, and it was enhanced by the addition of the root exudates of maize and tall fescue. The remediation efficiency of diesel-contaminated soil planted with maize or tall fescue was not inhibited by inoculating with the strain M23. Root weights in the soil inoculated with the strain M23 were greater than those in the non-inoculated soil. These results suggest that Pseudomonas sp. M23 is a promising bacterium to mitigate N₂O emissions during the remediation of diesel-contaminated soil.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.189-196
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• 2003

In this study, the vertical opening of the non-float midwater pair trawl net was maintained by controlling the length of upper warp. This was because the head rope was able to be kept linearly and the working depth was not nearly as changed with the variation of flow speed as former experiments in this series of studies have demonstrated. We confirmed that the opening efficiency of the non-float midwater pair trawl net was able to be developed according to the increase in front weight and wing-end weight. In this study, we described the opening efficiency of the non-float midwater pair trawl net according to the variation of front weight and wing-end weight obtained by model experiment in circulation water channel. We compared the opening efficiency of the proto type with that of the non-float type. The results obtained can be summarized as follows：1. The hydrodynamic resistance was almost increased linearly in proportion to the flow speed and was increased in accordance with the increase in front weight and wing-end weight. The increasing rate of hydrodynamic resistance was displayed as an increasing tendency in accordance with the increase in flow speed. 2. The net height of the non-float type was almost decreased linearly in accordance with the increase in flow speed. As the reduced rate of the net height of the non-float type was smaller than that of the net height of the proto type against increase of flow speed, the net height of the non-float type was bigger than that of the proto type over 4.0 knot. The net width of the non-float type was about 10 m bigger than that of the proto type and the change rate of net width varied by no more than 2 m according to the variation of the front weight and wing-end weight. 3. The mouth area of the non-float type was maximized at 1.75 ton of the front weight and 1.11 ton of the wing-end weight, and was smaller than that of the proto type at 2.0∼3.0 knot, but was bigger than that of the proto type at 4.0∼5.0 knot. 4. The filtering volume was maximized at 3.0 knot in the proto type and at 4.0 knot in the non-float type. The optimal front weight was 1.40 ton.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.13-20
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• 2012

This study was carried out to examine the effect of cutting condition on the growth of rooted cuttings and their subsequent growth of cut flower in plug cutting of Dendranthema grandiflorum 'Baekma'. The more leaves were attached to the cutting, the higher shoot growth of rooted cutting was observed. Cutting with two to six leaves was effective in shoot growth and rooting than any other treatment. Shoot growth of rooted cutting was not affected by cutting length, but rooting was better in 5 to 7 cm long cutting. Shoot growth and rooting of rooted cutting was promoted by increasing the cutting diameter, and rooting was better in 3.6-4.2 mm thick cutting than 3.1 mm thick cutting. As the treating concentration of NAA increased, shoot growth was inhibited and root length shortened in rooted cutting. Soaking with $100mg{\cdot}L^{-1}$ ${\alpha}$-naphtalene acetic acid (NAA) for 1 h was effective in shoot growth and rooting. Root growth such as root number, root length, and root weight was better in rooting medium mixed with 2:2 of peatmoss:perlite than the other treatments. When rooted cutting produced from cutting with four or six leaves was planted, better length, weight, and leaf number of cut flower was observed. In rooted cutting produced with 7-9 cm long cutting, growth of cut flower such as length, weight, and ray flower number was more effective than the others. Therefore, it is recommended that the 7 cm long and 3.6 mm thick cutting with four to six leaves is used to improve their rooting and subsequent growth of cut flower in plug cutting of Dendranthema grandiflorum 'Baekma'.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.195-201
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• 1983

This study was conducted to find out the damage of rice root nematodes on rice and determine the economic injury level. In pot experiments, rice root nematode, Hirschmanniella imamuri, suppressed the growth and reduced yield of a rice, Milyang 23, above critical levels. Tillering was depressed above 5, 000 nematodes per pot inoculum levels. Heading was also delayed by 6 days when inoculum level was above 20, 000. Weight of roots and grain yield in rice plants which inoculated with 20, 000 nematodes/pot were reduced by 41% and 31%, respectively. Economic injury level of rice root nematode appeared to be 1, 500 nematodes per 30g of fresh root on Aug. 30.

• Korean Journal of Plant Resources
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• v.33 no.1
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• pp.33-39
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• 2020

This study was carried out to provide basic information for mass breeding and cultivating the saplings of Camellia japonica. The germination rates did not show definite tendency according to the changes of seed weight at room temperature and 4℃ dry storage conditions. The germination rate of 4℃ wet sand storage was increased with seed weight, but showed very low germination rate for 120 days of storage. The germination rate was above 80% in 60 days, 90 days and 120 days, respectively, at 4℃ wet filter paper storage conditions. The average days taken for those germinations were about 30 days at room temperature and 4℃ dry storage conditions, but wet storage (sand, filter paper) condition took the shortly nearly 13 days for those germinations. Leaf number, leaf dry weight, stem diameter and root dry weight were higher than total average by more than 1.21 g for seed weight. Stem length was higher than the average by more than 1.01 g, plant dry weight was higher than the average by more than 0.81 g, and stem dry weight was higher than the average by more than 0.61 g. In the case of seed weight becoming heavier, seedling growth was good but T/R ratio tended to decrease. In order to increase the mass production of seedlings using Camellia japonica seeds, we need to specify the weight and size of those seeds. The 4℃ wet filter paper storage condition was evaluated as the most efficient method for the seed storage used for seeding.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.323-328
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• 2002

양파의 껍질에 칼금을 내고 꼭지와 뿌리를 절단한 후 회전하는 두 개의 롤러 위에 양파를 낙하시켜 구르게 하면서 그 위에 고압공기를 분사시켜 양파의 외각 껍질을 제거하는 공기분사식 박피장치의 최적 작동조건을 구명하기 위하여 수행한 시험결과를 요약하면 다음과 같다. 1, 박피장치에 고압공기를 분사하지 않았을 때, 롤러의 원주속도가 빠를수록, 양파의 무게가 가벼울수록 구름소요시간은 줄어들었고 직경방향 구름율이 가장 높았는데, 직경방향 구름소요시간이 가장 짧게 나타나는 주롤러의 원주속도는 2.4 m/s이었다. 2. 주롤러의 원주속도 2.4 m/s일 때 양파의 무게, 분사공기압 및 칼금수가 증가할수록 박피율은 증가하였으며, 박피율이 가장 높은 조건은 칼금수 4개, 분사공기압 3.5 kg/$cm^2$이상이었다. 3. 박피소요시간은 칼금수가 많을수록, 분사공기압이 높을수록 짧아지는 것으로 나타났고, 칼금수를 4개로 하고 분사공기압을 4.0 kg/$cm^2$이상으로 하면 박피소요시간을 2초 이하로 유지할 수 었다. 4. 양파의 껍질강도는 저장기일과 조건에 따라 다르므로 모든 양파의 박피를 위해서는 분사 공기압을 4.0 kg/$cm^2$이상으로 하고 공기분사시간을 2초에서 5초가지 조절할 수 있는 장치를 부착하는 것이 좋을 것으로 판단된다. 5. 시험에 사용된 양파는 무게는 150~350$\pm$30 g, 직경 60~120 mm의 크기로 우리나라에서 생산되는 양파의 98%에 적용이 가능할 것으로 생각된다.

• Korean Journal of Environmental Agriculture
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• v.3 no.1
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• pp.10-15
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• 1984

To get information on the behavior of phorate in vegetables under the subtropical conditions, phorate granule (10%) was applied to silt loam soil at the rate of 40㎏ a.i./ha and incorporated to 10㎝ soil depth just befere sowing. Insecticide residues in vegetables were determined with GLC and confirmed qualitatively with TLC. Phorate and its metabolites were absorbed by the radish and carrot roots and rapidly translocated into foliages. The compounds detected in vegetables were phorate, phorate sulfoxide, and phorate sulfone. Residue levels of compounds in radishes were higher in foliages than in roots and much more residues were present in leaf lamina than in midribs. The concentration of the total residues in vegetable roots was rapidly decreased with the time, while the amount of total residues in radish roots was increased with the time. Therefore, the rapid decline of residue levels in vegetables was mainly attributed to the dilution of insecticide residues by the rapid growth of these vegetables.

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.677-684
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• 2000

This study was conducted to investigate the relationship of development of root and soil condition and also to elucidate the difference between stands for mechanical and physical stability according to distribution of roots in the Norway Spruce (Picea abies [L.] Karst.) stands of 30 to 40 year of ages with different soil condition. In the root structure, remarkably different root pattern was shown among the three stands; Eberg$\ddot{o}$tzen stand showed large number f roots with much fine roots which deeply in vertical direction while Barbis stands had thicker root and small number of root than Eberg$\ddot{o}$tzen stand. The Weidenbrunnen stand showed differently half-vertical and plate root structure and the root developed not to be deeply compared to the other two stands. In the total number of root, Eberg$\ddot{o}$tzen stand had the most number of 74 and Barbis stand 33, Weidenbrunnen stand 57 respectively. Eberg$\ddot{o}$tzen stand had much more number of vertical root with 57 than the other two stand; Barbis 21 and Weidenbrunnen 36. In the total length of root, Weidenbrunnen stand showed to be longer than the other two stands and the length of horizontal root also showed longer. Regarding to the rates of horizontal root against vertical root, Eberg$\ddot{o}$tzen stand showed comparatively higher value as 1,2 than other two stands(0.5). In the total weight of root, Weidenbrunnen stand showed very high value compared with the other stands and ratio of vertical root against horizontal root was 0,16 which is very lower than the other two stands(0,4). The remarkable differences of root pattern of Norway spruce stands appeared in this study are through to be caused more by chemical property of soil such as acidity den the mechanical or physical factor of soil conditions.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.83-83
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• 2018

마카(Maca, Lepidium meyenii Walp)는 십자화과 두해살이풀로서 페루의 안데스 산맥이 원산지이며 세계 여러 나라에서 건강기능식품, 음료 등의 가공원료로 이용되고 있다. 최근 마카의 기능성 성분이 밝혀지면서 국내에서도 재배 면적이 증가하고 있으나 연작장해, 동계 저온으로 인한 고사 등으로 인하여 생산량은 매우 저조한 실정이다. 따라서 본 연구에서는 노지 환경에서 비닐피복과 지상부에 비닐 터널을 처리하여 겨울철 고사율을 줄이고 연장장해를 회피하여 마카를 안정적으로 재배하고자 실시하였다. 마카 재배는 경상북도 경산지역에서 2017년 9월 24일 파종하여 2018년 4월 30일에 수확하였으며, 처리는 비닐피복, 비닐피복+터널, 비가림하우스 및 대조구로 노지에서 무피복재배로 실시하였다. 동해에 의한 마카 고사율은 비닐피복과 노지재배에서 55.7, 79.1%였으나 비닐피복+터널과 비가림하우스에서는 3%이하로 조사되어 노지환경에서 비닐피복 후 지상부 터널설치로 동해를 방지할 수 있었다. 수확 시 마카의 생체중은 비가림하우스에서 주당 57.8g으로 가장 높았으며, 비닐피복+터널설치, 비닐피복 및 노지재배에서 각각 52.7, 21.3, 10g으로 조사되어 동계 지상부 15cm 지점의 평균온도(비가림하우스 : $3.4^{\circ}C$, 비닐피복+터널설치 : $1.9^{\circ}C$, 노지 : $-2.1^{\circ}C$)와 정의 상관관계를 나타냈다. 마카의 이용부위인 뿌리의 무게는 비가림하우스와 비닐피복+터널에서 각각 주당 15.5, 19.9g으로 조사되어 비교적 비닐피복+터널처리의 생육이 좋았으나 통계적 유의성은 없었다. 마카는 다닥냉이속 작물로 저온경과 후 뿌리비대가 이루어지는 속성을 가지고 있으나 생육후기 고온으로 인한 지상부 생육은 뿌리비대를 저하시키는 것으로 추정되어 3월 이후 온도관리는 좀 더 연구가 진행되어야 할 것이다. 노지와 비닐피복 재배에서는 뿌리의 무게가 주당 3.9, 2.7g으로 정상적인 수확이 불가능하였다. 마카를 노지에서 재배할 경우 비닐피복 후 지상부에 터널을 설치하면 연작장해 회피와 동해에 의한 고사율을 줄일 수 있어 안정적인 재배가 가능한 것으로 판단되었다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.28-33
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• 2008

Traditionally mungbean (Vigna radiata L.) sprouts has been stored after dehydration to decrease their decay. The study was done to determine the effect of watering for final 12 hours of harvest day on morphological characters and color of mungbean sprouts. The seeds of cv. Zhong Lu 1 were soaked in 50 ppm BA solution immediately before 4 hour aeration and then cultured for 6 days, when water-supplied for final 12 hours or not. After packaged with PE envelops, the sprouts stored 5 days at $8^{\circ}C$, and their morphological characters, fresh and dry weights, and colors were measured everyday. Compared to non-water supplied, water supplied sprouts had thicker hypocotyl diameter in middle part, and higher total fresh weight due to increment of cotyledon and hypocotyl ones although the two sprouts did nearly same in other characters. Only nonwater supplied sprouts showed higher color b value in hypocotyl than water supplied ones although there were not significant differences between them in other color-related characters, meaning that the latter ones were more rapidly decayed during their storage. In non-water supplied sprouts, number of lateral roots, hypocotyl and root lengths, total fresh weight, brightness of hypocotyl and root was decreased since 3 days after storage but cutting resistance of hypocotyl was done since 5 days.