This study was carried out to allelopathic effects of aqueous extracts on Coronopus didymus in order to investigate the competitive dominant in plant ecosystem and possibility application in natural herbicide. Number of species and species diversity for close to patch of C. didymus was decreased gradually site #1 (7, 1.76), site #2 (5, 1.34) and site #3 (5, 1.25). It was generally decreased the relative germination ratio (r=-0.731, p＜0.01), the mean germination time, the relative elongation ratio (r=-571, p＜0.01, r=-0.730, p＜0.01), the relative fresh weight (r=-0.743, p＜0.01), development of root hairs of receptor plants by concentration of the aqueous extracts from C. didymu. But they were different from the growing regions, the kind of receptor plants and the treatment of the aqueous extracts. Especially, it was differently effected among growing regions that inhibited more radicle than shoot by the aqueous extracts concentration of C. didymus. Total phenolic compound in the aqueous extracts of C. didymus analyzed about 23.0±1.1 mg/g. Total phenolic compounds of soil in survey area was increased gradually site #1 (0.072 ± 0.002 mg/g), site #2 (0.082 ± 0.003mg/g) and site #3 (0.092 ± 0.004 mg/g). We think that the aqueous extracts of C. didymu showed allelopathic effects on other plants. Therefore, C. didymu hold the competitive dominant of plant ecosystem in Jeju Island and possibility application of natural herbicide.

The study researched germination of the plants and growth of Fungus according to concentration of aqueous extracts in order to provide basic data for developing natural agricultural resources by using Persicaria longiseta. The seed germination of Amaranthus spinosus was inhibited at 25% P. longiseta extract, while Agrostis stolonifera ssp. palustris was not affected at all concentrations tested. Especially, the seed germination rate and fresh weight of Trifolium incarnatum at 20% P. blumei extract were higher than those of control plot. The early growth of most receptor plant seedlings was promoted at 25% and 50% of P. blumei extracts, but the radicle growth of all receptor plants was significantly inhibited at > 25% of P. longiseta extract. The response of receptor plants to P. longiseta extract was different according to the plant species and the plant parts. The growth of plant pathogenic fungus in PDA medium showed an increasing inhibition tendency with increasing concentrations of P. longiseta extract. Especially, P. longiseta extract showed the greatest antimicrobial activity against Phytophthora infestans, Phythium graminicola, and Pythium venterpoolii. The content of total phenolic compound in P. longiseta was higher in leaves (1082.3 mg/L) but lower in roots (228.6 mg/L) and stems (207.8 mg/L), which is an allelopathic chemical. As these results are summarized, P. longiseta have competitive advantage because they release phenolic compounds with allelopathic effect and affect on germination, growth and fungi growth on underground flora compared to native plants and they have eligibility for natural herbicide and germicide.

본 연구는 개여뀌를 이용하여 친환경 농자재로 개발하기 위한 기초자료를 제공하기 위해 수용성 추출액의 농도에 따른 재배작물인 감자생육에 미치는 알레로패시 효과를 조사하였다. 감자 시험구 처리는 개여뀌추출물 무처리, 25%, 50%, 75%, 100%로 하였으며, 개여뀌추출물의 처리는 정식 1일 후부터 5일 간격으로 처리구에 따라 관주하였다. 개여뀌의 수용성 추출액농도가 증가함에 따라 대조구에 비하여 맹아가 완료되는 시기가 1일이 빨랐고, 경수는 0.3-0.4/1주 개가 많았다. 경장은 생육초기에는 개여뀌추출물 처리구가 무처리구에 비해 컸으나, 생육 중반 이후에는 차이를 보이지 않았으며, 경직경 및 지상부 생체중은 개여뀌처리구가 무처리구에 비해 양호한 경향을 보였으나 통계적 유의성은 없었다. 감자의 총수량/㎡은 개여뀌를 처리한 100%구에서 13.8 kg/m2로 가장 많았으며 처리간에 유의차가 인정되었다. 감자의 크기별 개수는 4 g 이하, 5-30 g 미만의 괴경 수량은 각 처리간에 일정한 경향을 보이지 않았으나 31 g 이상의 괴경 수량은 무처리구에 비해 개여뀌 수용성 추출물 처리구가 현저히 높았다. 이들 결과를 종합하면 개여뀌의 allelopathy 효과는 감자의 생육과 수량형질이 촉진되어 친환경 비료로써 활용 가능성을 가지고 있는 것으로 판단된다.

서양금혼초의 군락 형성에 따른 경쟁적 우세원인을 규명하고 친환경농자재 개발을 위한 기초자료로 제공하고자 생육특성과 Allelopathy 효과를 알아보았다. 서양금혼초의 생육특성은 예초지역과 비예초지역간의 묘조(苗條) 수, 지상부 직경과 화주 수를 비교한 결과 예초지역의 묘조(苗條) 수, 지상부의 직경과 화주수가 비예초지역보다 높은 것으로 조사되었고, 서양금혼초의 수용성 추출액에 대한 레드클로버(Trifolium pratense), 들묵새(Festuca myuros), 도깨비바늘(Bidens bipinnata) 등 실험식물 14종 대해 발아와 생장 실험 결과 일반적으로 수용성 추출액의 농도가 증가함에 따라 검정식물의 발아율, 유식물의 뿌리털, shoot, root의 생장이 억제되었고 검정식물의 종류와 부위에 따라 억제정도에 있어서 차이를 보였다. 또한 서양금혼초의 수용성 추출액에 대한 실험곰팡이의 생장에 있어서는 Pythium속, Phytophthora속은 수용성 추출액의 농도가 높아짐에 따라 성장이 억제되는 경향을 보인 반면, Rhizoctonia속인 경우에는 농도가 높아짐에 따라 생장억제 현상이 뚜렷하지 않았다. 이와 같은 결과를 종합하여 보면 서양금혼초의 예초는 서양금혼초의 Split현상을 유도하여 더 많은 영양번식과 종자번식을 일으켜 군락을 형성하고, 서양금혼초에 함유된 allelochemicals에 의해 타 식물체의 발아와 생장, 미생물의 생장 등에 관여하기 때문에 제주도내 생태계에서 경쟁적 우위를 점하고 있으며, 친환경농자재로서의 활용 가능성이 있는 것으로 판단되었다.

In order to evaluate the weed suppressing effect of Solanum viarum Dunal. In this study species diversity in patch of S. viarum and allelopathic effects of the aqueous extracts on S. viarum were investigated. Number of species and species diversity in site close to patch of S. viarum were decreased gradually 1site (7.7±2.0, 1.5±0.2), 2site (5.3±1.2, 1.2±0.2) and 3site (4.0±1.7, 0.9±0.1). And total phenolic compounds of soil in survey area were increased gradually site1 (0.16±0.01㎎ g⁻¹), site2 (0.17±0.01 ㎎ g⁻¹) and site3 (0.22±0.02㎎ g⁻¹). So the number of species and species diversity (r=-0.692, P＜0.05) were negatively correlated with increased total phenolic compounds of soil in the survey area. The relative germination ratio, the mean germination time, the relative elongation ratio, the fresh weight and the dry weight of receptor plants are generally getting decreased while the concentration of the aqueous extracts from S. viarum escalate. But every ratio was various depending on the growing regions, the kind of receptor plants and the treatment of the aqueous extracts. Especially, the radicle by injection of the aqueous extracts concentration of S. viarum was influenced more than the shoot on the same condition. The total phenolic compounds on region of S. viarum was gradually increased in stems (fresh 0.56±0.02㎎ g⁻¹, dry 1.58±0.08㎎ g⁻¹), roots (fresh 1.77±0.07㎎ g⁻¹, dry 2.64±0.06㎎ g⁻¹), leaves (fresh 6.01± 0.14㎎ g⁻¹, dry 7.04±0.29㎎ g⁻¹), seeds (fresh 6.21±0.17㎎ g⁻¹, dry 9.08±0.73㎎ g⁻¹) in order. On the contrary, the negative correlation on germination and growth of receptor plants was shown by total phenolic compounds on the each parts of S. viarum. We think that the aqueous extracts of S. viarum showed allelopathic effects on other plants. Therefore, S. viarum holds the higher competitiveness in plant community in Jeju Island and makes possibility of application as natural herbicide.

This study was carried out to germination characteristics by temperature conditions and allelopathic effects of aqueous extracts on Amaranthus spinosus L. in order to investigate the competitive dominant in plant ecosystem and possibility application of natural herbicide. A. spinosus L. sprouted after 24 hour from seeding in 30～4 5℃ treatment. The germination ratio of A. spinosus L. was the highest estimated at 63.3(±2.9)% in 40℃ treatment, followed by 33.3(±2.9)% in 35℃, 1.7(±2.9)% in 30℃ and 5.0(±0.0)% in 45℃ treatment. It was generally decreased the Relative Germination Ratio(RGR), the Relative Elongation Ratio(RER), the Relative Fresh weight Ratio(RFR) of receptor plants by the aqueous extracts of concentration of A. spinosus L. but it was differently inhibited the kind of receptor plant species. And it was different effected among growing regions that aqueous extracts of concentration of A. spinosus L. inhibited more root than shoot. The total phenolic compounds content of A. spinosus L. was decreased gradually middle, first and last of growth stage, and gradually decreased to leaves, roots and stems. We think that A. spinosus L. appeared high germination ratio at a short period and showed allelopathic effects on other plants. Therefore A. spinosus. L. hold the competitive dominant of plant ecosystem in Jeju Island and possibility application of natural herbicide.

Present study evaluated the low-temperature destruction of n-hexane and benzene using mesh-type transition-metal platinum(Pt)/stainless steel(SS) catalyst. The parameters tested for the evaluation of catalytic destruction efficiencies of the two volatile organic compounds(VOC) included input concentration, reaction time, reaction temperature, and surface area of catalyst. It was found that the input concentration affected the destruction efficiencies of n-hexane and benzene, but that this input-concentration effect depended upon VOC type. The destruction efficiencies increased as the reaction time increased, but they were similar between two reaction times for benzene(50 and 60 sec), thereby suggesting that high temperatures are not always proper for thermal destruction of VOCs, when considering the destruction efficiency and operation costs of thermal catalytic system together. Similar to the effects of the input concentration on destruction efficiency of VOCs, the reaction temperature influenced the destruction efficiencies of n-hexane and benzene, but this temperature effect depended upon VOC type. As expected, the destruction efficiencies of n-hexane increased as the surface area of catalyst, but for benzene, the increase rate was not significant, thereby suggesting that similar to the effects of the reaction temperature on destruction efficiency of VOCs, high catalyst surface areas are not always proper for economical thermal destruction of VOCs. Depending upon the inlet concentrations and reaction temperatures, almost 100% of both n-hexane and benzene could be destructed. The current results also suggested that when applying the mesh type transition Metal Pt/SS catalyst for the better catalytic pyrolysis of VOC, VOC type should be considered, along with reaction temperature, surface area of catalyst, reaction time and input concentration.