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 귀화식물인 Solidago altissima, Amaranthus retroflexus, Sida spinosa 등을 이용하여 친환경 농자재로 개발하기 위한 기초자료를 제공하기 위해 수용성 추출액의 농도에 따른 수용체 식물의 발아 및 유식물 생장과 실험 병원균의 생장을 조사하였다. 공여체식물에 따른 수용성 추출액 농도가 증가됨에 따라 대부분 검정식물의 상대발아율은 감소하는 경향을 보이는데 S. spinosa(r = -0.540, p＜0.01), Physalis wrightii(r = -0.693, p＜ 0.01), A. retroflexus(r = -0.724, p＜0.01), S. altissima(r = -0.728, p＜0.01), Eclipta prostrata(r = -0.779, p＜0.01) 순으로 감소하는 경향이 큰 것으로 조사되었고 평균발아일수도 처리구 농도가 증가함에 따라 발아하는데 소요되는 시간이 증가 되었으며(r=0.769, p＜0.01) 공여체식물과 검정식물에 따라 약간의 정도 차이를 보였다. 또한 공여체식물의 수용성 추출액 농도가 증가함에 따라 유식물의 지상부의 길이(r = -0.587, p＜0.01), 지하부의 길이(r = -0.741, p＜0.01), 생체량(r = -0.574, p＜0.01)과 뿌리털의 발생도 감소하였다. 한편 공여체식물의 수용성추출액 농도 증가에 따른 검정 병원균의 생장은 Botrytis cinerea(r = -0.266, p＜0.05), Diaporthe citri(r = -0.323 p＜0.01), Colletotrichum gloeosporioides(r = -0.512, p＜0.01), Pythium ultimum(r = -0.581, p＜0.01), Rhizoctonia solani(r = -0.806, p＜0.01) 순으로 생장이 억제되었다. 제초 및 항균활성을 보이는 수용체식물의 총 페놀 함량은 S. altissima 17.3±0.5mg/g, A. retroflexus 13.1±0.3mg/g, P. wrightii 12.0±0.4mg/g, S. spinosa 9.5±0.1mg/g, E. prostrata 4.1±0.1mg/g 순으로 분석되었다. 이들 결과를 종합하면 귀화식물인 수용체식물들은 자생식물과의 경쟁을 함에 있어 알레로패시 효과를 나타내는 페놀 화합물 등이 수관 내 토양으로 방출하여 하부식생에 대한 발아 및 생장과 토양미생물 생장 등에 영향을 주기 때문에 경쟁적 우위를 점하고 있으며, 천연제초제 · 살균제로서의 활용 가능성을 가지고 있는 것으로 판단된다.

Vinegar has been considered as a potential organic herbicide, but more knowledge is needed about acetic acid concentration, application volume and use of adjutants on weed control. In this study, we determíned optímum acetic acid concentration and spraying time on several weed species. Vinegar is more effective in broadleaf weeds than grasses. Vinegar is also effective in controlling younger weeds such as 3rd weeks to 4th weeks after emergency. For example, 3rd weeks after emergency weeds were easily controlled at 2-3% of vinegar solution. But 4th weeks after emergency weeds were controlled at 4-5% of vinegar. Therefore vínegar concentration was recommended about 5%, and application time was when the weeds were young - within 31eaf stage.

Common thistle contains water-soluble substances that are phytotoxic to neighboring plant species. A series of aqueous extracts from leaves, stems, roots and flowers of common thistle (Cirsium pendulum Fisch.) were assayed against alfalfa (Medicago sativa) seedlings to determine their allelopathy, and the results showed highest inhibition in the extracts from flowers and leaves, and followed by stems, and roots. The extracts at 40 g dry tissue L-1(g~;L-1) applied on filter paper in a Petri-dish significantly inhibited root growth of test plant by 87%. Methanol extracts at 100 g L-1 from leaves inhibited root growth of alfalfa and barnyardgrass (Echinochloa crus-galli) by 89 and 98%, respectively. Hexane and ethylacetate fractions of common thistle reduced alfalfa root growth more than did butanol and water fractions. Incorporation into soil with the leaf residues at 100g~;kg-1 inhibited shoot fresh weights of barnyardgrass and eclipta (Eclipta prostrate) by 88 and 58%, respectively, showing higher sensitivity in grass species. These results suggest that common thistle plants had allelopathic potential for eco-friendly vegetation management, and that especially their activities were differently exhibited depending on plant part.

Herbicidal activity of δ -aminolevulinic acid(ALA), an intermediate for the biosynthesis of tetrapyrroles such as chlorophyll, heme, bacteriochlorophyll, and vitamin ~textrmB12 analogues, was examined to determine the variation in phytotoxic potential against different plant species as affected by different application methods. Seed-soaking treatment, ALA at low concentrations did not affect shoot and root lengths of test plants while at highest concentration reduced them by 20 to 30%. Alfalfa showed the most tolerant response to ALA in both pre- and post-emergence application, and followed by rice. When applied with pre-emergence, cotyledons of Chinese cabbage were severely bleached with 0.5 mM of ALA at 24 hrs after application, and root growth of rice, barnyard grass, and alfalfa was significantly inhibited with increasing of concentration. With post-emergence application, ALA at 2 to 4 mM reduced shoot and root growths of Chinese cabbage and barnyard grass completely. Herbicidal effects of ALA were more enhanced in the treatment combined with 2,2-dipyridyl sthan single application in barnyard grass and Chinese cabbage. The results suggest that alfalfa was the most tolerant to ALA among the tested plants, and that post-emergence application of ALA exhibited greatest photodynamic activity against tested plants.

할미꽃의 뿌리에 함유되어 있는 제초활성물질의 확인과 동정을 위하여 이들을 추출 정제하고 활성성분 및 제초활성을 조사하여 다음과 같은 결과를 얻었다. 1. 각종 칼럼크로마토그래피법과 Prep. HPLC의 순차적인 적용에 의해 제초활성물질이 포함된 할미꽃 뿌리의 메타놀추출물을 정제하여 2개의 활성분획을 획득하였다. 2. 최종적으로 얻어진 활성분획들을 100ppm의 농도로 조제하여 처리한 결과, 식용피 유근의 생장 억제율은 대조구에 비해 각각 48% 및 60%로 나타났다. 3. GC-MS Spectrometry에 의해 분리된 활성분획 중의 성분들을 기존자료들과 비교하여 수종의 지방산 에스테르, 2종의 탄화수소류, squalene, evidonol 및 1종의 diazepin 관련 화합물이 동정되었다.

잡초발생전에 처리하는 제초제에 대한 품종간 내약성을 검정하기 위하여 엽기별로 수심 및 온도처리를 달리하여 얻어진 약간의 결과를 요약하면 아래와 같다. 1. 3엽기에 수심이 1cm에서 9cm로 깊어 질수록 품종에 관계없이 낙해가 심하였으나 묘령이 진전된 7엽기에서는 품종간 수심처리의 영향이 경미하였다. 2. Saturn-S의 용해도는 타 처리여초제에 비하여 높은 관계로 수심이 1cm에서 9cm로 증가될수록 희석되어 낙해가 감소되었다. 3. 온도가 10℃ 에서 30℃ 로 상승할수록 낙해는 증가되었고 "토일"이 가장 민감하게 반응하여 건물중의 감소를 보였으며 진흥이 가장 큰 내락성을 보였다. 4. 품종간의 내략성차이는 품종의 형태 및 생리적 특성차에 의하여 나타나는 것을 간주된다나는 것을 간주된다