• Korean Journal of Weed Science
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• v.5 no.2
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• pp.96-102
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• 1985

A study on the competition-ecological classification of the 10 prominent paddy weed species around bulrush (Scirpus juneoides) to simplify the weed problem concept for the rice production. A serial assessments on the competition ability in space and dry matter production(nutrient depletion) of respective weed species and paddy rice, and the data were used to compute the phenotypic similarity by Single Link Clustering method. Both growth response of weed species in mono- and under the paddy rice standing was very similar (r = 0.969), but the reduction rate as affected by paddy rice standing was negatively correlated with the ability in space-competition(r=-0.513). Dendrogram of 10 weed species based on the phenotypic similarity computed in 4 characters in mono- and under the paddy rice standing was also similar, as Echinochloa c., Ludwigia p., Cyperus s., and Scirpus m. in I-group, Eleocharis k., Scirpus j, in II-group, and Juncus e., Potamogeton d. in III-group, respectively. Also, that of paddy rice to 10 weed species showed Fimbristylis m., Scirpus j., Eleocharis k., Scirpus m., Juncus e. in I-group, and Ludwigia p., Potamogeton d., Monochoria v. in II-group, respectively. The integrated dendrogram by the above two data indicate the I-group with Fimbristylis m., Scirpus j., Eleocharis k. and Juncus e., as higher growth response with relatively lower competition ability to paddy rice, II-group with Cyperus s., Echinochloa c., Potamogeton d., and Ludwigia p., as higher both in growth and competition, and the last, III-group with Monochoria v., and Scirpus m., as lower growth but higher competition, respectively.

• Journal of Environmental Impact Assessment
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• v.17 no.4
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• pp.225-233
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• 2008

An Environmental Specimen Bank (ESB) is an archive for samples that can be used to document and assess the quality of the environment in which we live. An ESB program looks at changes in the concentration of human and environmental specimens over long periods of time through retrospective analysis of archived samples of a particular area collected at regular intervals. The idea of ESB was first proposed by German and American scientists in the early 1970s and has been established since 1979 in Germany, USA, and Japan. Korea plans to establish a National Environmental Specimen Bank (NESB) in 2010. The NESB will be able to assess and improve the quality of analytical measurements as well as to compare the past and current environmental quality as a time capsule. The concept and design for the NESB facility was developed and its Standard Operation Procedures (SOPs) are being developed based on an evaluation of ESBs and SOPs of Germany, USA, and Japan. Environmental specimens proposed for banking are based on typical representatives of every level of the food chain from each type of ecosystem that are widely distributed thus enabling comparisons between different sampling areas. Through retrospective analysis of environmental specimens, the NESB will improve the reliability of environmental monitoring, ecological risk assessment, and health impact assessment.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.80-93
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• 1997

Allelopathic compounds as naturally occurring herbicide have originally reported from local vegetation since B.C. 300. These compounds are known as secondary plant metabolites which released from plants into the environment often attract or repel, nourish or poison other organisms. In recent, many natural plant allelochemicals be used to attempt to biologically or ecologically control weed among worldwide weed scientists. Some allelochemicals have also used as fungicides, insecticides, and nematodicides, and were less than man-made agrochemicals to damage the global ecosystem. It makes efficient use of resources internal to the farm, relies on a minimum of purchased inputs. Some scientists selected for allelopathic activity when breeding weed-controlling cultivars of rice, sorghum, cucumber, surflower etc. Thus, this paper is focused on allelopathic compounds isolated from cultivated crop with the high potential of prospective herbicides. The most environmentally acceptable and sustainable approach to utilization of allelopathy for weed control is to develop plant cultivars with proven allelopathic characteristics. In rice accessions, there are 60 cultivars/lines which have known as allelopathic activity and some of these cultivars control weed more less 90% within certain radius of activity. These accessions are originated from 15 countries including Korea, Japan, USA, India, Philippines, Indonesia, Laos, Taiwan, Afghanistan, Mali, Pakistan, Colombia, Egypt, China, and Dom. Rep. From these cultivars, the most common allelopathic compounds identified in rice are p-Hydroxybenzoic, Vanillic, p-Coumaric, and Ferulic acids. In addition, allelopathic lines of the following crop have shown inhibition of weed growth : beet (Beta vulgaris), lupin(Lupinus spp.), com(Zea mays), Wheat(Triticum aestivum), oats(Avena spp.) peas(Pisum sativum), barley(Hordeum vulgare), rye(Secale cereale), and cucumber(Cucumis sativus). Thus, future allelopathy research must be designed its potentially phytotoxic propertices and the ecotoxic features of the allelochemicals from release to degradation ; its ecological sustainability, its allelopathic effect in early growth. stages, and selectivity properties in combination with chemical stages, and selectivity properties in combination with chemical concentrations. Also, research approach in allelopathy might be screened for highly allelopathic germplasm collection of crops, the idea being to ultimately transfer this agronomic character into improved cultivars by either conventional breeding or other genetic transfer techniques.

• Weed & Turfgrass Science
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• v.3 no.1
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• pp.50-55
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• 2014

This study is aimed at classifying the syntaxa of Ceratopteris thalictroides dominant community on the Nakdong River, and to collect basic data for research of habitat. The communities were carried out by using the Z.-M. School's method and numerical classification technique. The result of syntaxa was classified three communities such as Persicaria japonica-Ceratopteris thalictroides community, Lindernia procumbens-Ceratropteris thalictroides community, and Limnophila indica-Ceratopteris thalictroides community. The ordination analysis displayed the vegetation types with respect to complex environmental gradients. After ordination and clustering analysis, the effective humidity, soil stability, trampling effects, anthropogenic effects and flooding frequency were identified as the important factors deciding the vegetation pattern. It was pointed out to establish a long-term ecological site for protecting such vulnerable vegetation against overexploitation and global climate change.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.247-255
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• 2016

This study was conducted to provide basic information for weed control by surveying the occurrence of weed species in turf sod production areas. Surveys of weed species occurred in turf sod production areas were conducted in Jangsung-gun, Jeonnam province from September 2014 to May 2016. Total 50 sites of turf sod production areas in two soil conditions were investigated. On the upland soil condition in turf sod production areas, 66 weed species in 27 families were identified and classified to 49 annuals and 17 perennials and on the paddy soil condition, 69 weed species in 22 families were identified and classified to 53 annuals and 16 perennials. Based on the importance values, the most dominant weed species on the upland soil condition in the first survey (September 2014) was Digitaria ciliaris (8.49%), followed by Erigeron annuus (7.94%) and Rorippa indica (6.56%). In the second survey (May 2016) was Oxalis corniculata (7.26%), followed by Capsella bursa-pastoris (6.21%) and Conyza canadensis (6.21%). Whereas the most dominant weed species on the paddy soil condition in the first survey (September 2014) was Erigeron annuus (9.52%), followed by Mazus pumilus (7.41%) and Cyperus iria (6.82%). In the second survey (May 2016) was Commelina communis (5.08%), followed by Alopecurus aequalis (5.08%) and Erigeron annuus (4.79%). This information could be useful for estimation of future weed occurrence and effective weed control methods in turf sod production areas in Jangsung-gun, Jeonnam Province.

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.355-358
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• 2017

Amur silver grass, Miscanthus sacchariflorus is one of the promising biofuel weeds. A damage of noctuid pest, Leucapamea askoldis was firstly observed from Amur silver grass in Hwasun silver grass plantation during the survey of insect pests of Amur silver grass in Iksan, Hwasun, and Sancheong plantation areas in Korea. The host of L. askoldis was not known yet in Korea. The L. askoldis damage was observed as larval feeding on newly grown shoots and roots of M. sacchariflorus close to soil surface from early May in 2013. Investigated larval density was $1.6{\pm}1.1per\;m^2$ on April 4 and damage rate of shoots was $0.8{\pm}0.4%$ on May 4, 2013. The larvae bore into shoots of M. sacchariflorus and feed on the inside of plant. The damaged shoots are easily pulled out and distinguished by the boring hole on the shoots. L. askoldis was potential insect pest in M. sacchariflorus plantation areas.

• Korean Journal of Weed Science
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• v.14 no.1
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• pp.71-80
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• 1994

Nepal, with its unique geographical and ecological features due to its abrupt rise in altitude, plays significant role in biological evolution. Existence of numerous wild relatives of the present-day cultivated agricultural crop plants in this small Himalayan nation may serve as a potential source of several yet unidentified desirable genes that are needed for future incorporation in the improvement of cultivated crop plants. This report includes 82 different wild relatives of 41 genera under 19 families of 37 agricultural crops of Nepal(Table 1). It serves as the sample of the glossary of these wild relatives of crop plants in Nepal. Under food grain crop plants of gramineae, leguminoceae and polygonaceae families, 16 different wild species namely wild rices(7 species), wild relatives of wheat plant(3 species), wild arhar(3 species), wild fingermillets(1 species) and wild buckwheat(2 species) have been identified in different parts of the country. Similarly, under vegetable crop plants of Araceae, Amaranthaceae, Crucifereae, Cucurbitaceae, Dioscoreaceae, Labiteae, Leguminosae, Liliaceae, Malvaceae, Polygonaceae, Solanaceae and Umbellifereae, 37 different wild species-wild colocasia(1 species), wild amaranths(3 species), wild leafy vegetables(2 species), wild gourds(3 species), wild cucumber(1 species), wild yams(4 species), wild mints(3 species), wild fenugreeks(4 species), wild pea(1 species), wild beans(3 species), wild garlics(2 species), wild spinach(3 species), wild lady's finger(1 species), wild spinach(3 species), wild eggplants(2 species) and wild carrot(one species) have also been identified. In case of wild relatives of cultivated orchard plants, 11 different wild species namely wild mango(one species), wild banana(one species), wild strawberry(one species), wild pear(one species), wild cherries(2 species), wild apple(one species) and wild grapes(3 species) have been identified, Among 19 different wild species of economic crop plants, five wild species of sugarcane, one species of wild sunhemp, two wild relatives of cotton, three wild relatives of rose, two wild species of tobacco, four wild species of turmeric and two wild species of tea have also been identified. This report includes only sample of the total wild species of the present-day cultivated agricultural crop plants. Further exploration on this economic botany will help the country in cataloging the wild relatives of cultivated crop plants and their future use in crop improvement.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.122-127
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• 1998

This experiment was conducted to investigate the response of the fertilizer three factors on the growth of Alopeuclus aequalis Sobol. var. amurensis(Kom.) Ohwi. The growth of Alopeuclus aequalis Sobol. var. amurensis(Kom.) Ohwi. such as plant height, tiller number and dry matter production were vigorous on the plot fertilized with phosphate(P, NP, PK, NPK). The main effect of plant height elongation and dry matter production were significant for phosphate and nitrogen, and their interaction effect was recognized, too. Tiller growth and panicle number were mainly affected by phosphate. The growth of Alopeuclus aequalis Sobol. var. amurensis(Kom.) Ohwi. depended mostly on phosphate among the fertilizer three factors. The effect of nitrogen fertilizer was very different according to phosphate fertilizer treatment.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.188-198
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• 2015

This study was conducted in order to investigate the distribution pattern of weeds and ecological characteristics on the dry field in the Eastern region of Korea. The weed species data were obtained from 12 regions in Gangwon-do and Gyeongsang-do. 150 taxa were recorded from three main distinguished habitats; inside of dry field (IDF), embankment around the end of dry field (EDF), levee slope of dry field (LS). The weed species of three different habitats were IDF 83 taxa, EDF 133 taxa and LS 105 taxa. The species showing higher rNCD value was Portulaca oleracea in IDF, Digitaria sanguinalis in EDF and Humulus japonicus in LS. Compositae was dominant family followed by Gramineae, Polygonaceae and Leguminosae. Life form was distinguished as Th-R5-D4-e and three different habitats showed the same results. Disturbance index was analysed as IDF 83.1%, EDF 68.4%, and LS 62.9%. Naturalized rate was analysed as IDF 28.9%, EDF 22.6%, and LS 20.0%. These results indicate that the weeding management, land use intensity, and human interference effect on the distribution index and naturalized rate of weed.

• Weed & Turfgrass Science
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• v.4 no.4
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• pp.315-320
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• 2015

Burcucumber (Sicyos angulatus) is an annual invasive plant species originated from North America. This species grows by twining around tree trunks, and blocks other plants from photosynthesis. Thus, it has caused the destruction of the ecosystem and biological diversity by threatening native plants. This study was performed to find out the effect of different soil water content (20%, 13%, 10%, 3%) and various shading degrees (0%, 60%, 80%) on the growth and photosynthesis-related activity of burcucumber. In the responses of burcucumber to soil water content, plant height (PH), leaf length (LL), leaf width (LW) and photosynthetic efficiency (PE) were lower at 20% water content than 10% reflecting that burcucumber plant grow well in the less dry soil and shows poor growth under wet soil condition. In shading experiment, PH, LL, LW and PE were lower at 80% than 60% shading and in general, the growth characteristics were lowered as the shading intensity increased. The improved growth of burcucumber under highly or moderately shaded condition implies that the plant can grow well without growth retardation and can be adapted to shading condition with other tall plant species including tree. Further study on the combination effects of above factors should be conducted in future for effective ecological control of burcucumber.