• Korean Journal of Weed Science
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• v.15 no.4
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• pp.254-261
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• 1995

The nationwide weed survey was conducted in lowland rice fields over whole country of Korea in 1992 in order to determine a change of weed community and to identify a major dominant weed species and/or problem weed. Based on morphological characteristics of weeds, population ratio of broad leaf weed was 42.6%, grasses weed-9.0%, sedges-33.4% and others were 15.0%. Annual weed was 33.4% while perennial weed was 66.6% in terms of life cycle of weeds. Meanwhile, there was different weed occurrence as affected by planting method of the rice plant. In hand transplanted paddy fields predominant weed species was Sagittaria trifolia L., Monochoria vaginalis Presl., and Aneilema japonica Kunth. In machine transplanted rice fields of infant and young rice seedling Eleocharis kuroguwai Ohwi. and S. trifolia L. were more predominant. There was high occurrence of M. vaginalis, Echinochloa crus-galli L., and Leesia japonica Makino in water seeding while E. crus-galli and Cyperus serotinus Rottb. were predominant weed species in dry seeded rice. Monoculture of the rice plant would cause to high occurrence of E. kuroguwai, S. trifolia, M. vaginalis, E. crus-galli, and Sagittaria pygmaea Miq and there was higher population of S. trifolia, S. pygmaea, M. vaginalis, E crus-galli, and E. kuroguwai in double cropping system based on rice culture. In particular, there was high different weed occurrence under different transplanting times. E. kuroguwai, S. trifolia, S. pygmaea, M. vaginalis, and C. serotinus were higher population at the transplanting of 25 May and S. trifolia, E crus-galli, C. serotinus, and M. vaginalis at 10 June and S. pygmaea, E. kuroguwai, M. vaginalis, S. trifolia, and E. crusgalli at 25 June in Korea, respectively. Autumn tillage in terms of tillage time would cause more predominant weed species such as S. trifolia, E. kuroguwai, M. vaginalis, and S. pygmaea while spring tillage was higher population of E. kuroguwai, S. trifolia, E. crusgalli, M. vaginalis, and S. pygmaea. In plain area of paddy field there was higher occurrence of E. kuroguwai, S. trifolia, M. vaginalis, E. crus-galli, and S. pygmaea and in mid-mountainous area S. trifolia, E. kuroguwai, M. vaginalis, E. crus-galli, and Ludwigia prostrate Roxb. while in mountainous area S. trifolia, M. vaginalis, Potamogeton distinctus Ben., E. kuroguwai, and E. crus-galli were. In 1992 the most ten predominant weed species at the rice field of Korea based on summed dominant ratio(SDR) were E. kuroguwai > S. trifolia > E. crus-galli > M. vaginalis > S. pygmaea > C. serotinus > L. prostrate > P. distinctus > A. japonica > Scirpus juncoides Roxb.

• Korean Journal of Weed Science
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• v.4 no.1
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• pp.11-18
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• 1984

The effect of transplanting method of rice seedlings on weed occurrence was investigated at the Yeongnam Crop Experiment Station in 1983. Rice was transplanted by hand and machine and eleven common herbicides were applied. The greatest weeds were harvested from the plot that rice was not transplanted and more weeds encountered at machine transplanted plot than hand transplanted plot. The degree of weed suppression by rice plant itself was 50% for machine transplatning and 55% for hand transplanting, respectively. Simpson index and community dominance of weed species were the highest in hand transplanting and followed by machine transplanting and no rice plot in order. Rice grain yield was exponentially correlated with the amounts of weed occurrence and more yield loss exhibited at machine transplanting than hand transplanting in the same amount of weeds. In the herbicidal activity, most of herbicides performed better at hand transplanting than machine transplanting while the degree of difference between transplanting methods varied depend on herbicide used.

• Korean Journal of Weed Science
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• v.13 no.2
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• pp.159-163
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• 1993

This research was conducted at the Crop Experiment Station to determine the changes of weed flora under direct seeded rice cultivation in dry paddy field from 1989 to 1992 and to establish an effective weed control strategy in direct seeded rice cultivation. With the continuous rice growing under direct seeded rice cultivation in dry paddy field, there were more occurrence in grasses and annual weeds while broadleaf and perennial weeds were diminished. The predominant weeds were aquatic weeds such as Eleocharis kuroguwai, Echinochloa crusgalli, and Monochoria vaginalis in machine transplanted rice paddy field while there were predominant of semi aquatic weed species such as E. crusgalli, Digitaria sanguinalis, Bidens tripartita, Aeschynomene indica, and Arthraxon hispidus in continuous direct seeded rice cultivation in dry paddy condition. Based on the vegetative analysis of weeds in terms of simpson index and community dominance, there was more distribution of weed species in direct seeded rice cultivation on dry paddy condition while only distributed with 1-2 weed species in machine transplanted rice paddy field. In similarity coefficient, there was a gradual increase up to 67% of weeds with the continuous direct seeded rice cultivation in dry paddy condition for 4 years starting from 41% of similarity coefficient.

• Weed & Turfgrass Science
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• v.4 no.2
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• pp.85-94
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• 2015

The weed flora in the mulberry fields were investigated in Suwon, Jeonju, and Buan in May, July, and September of 2014. The objectives of this study were to use the survey data for establishing weed control methods and to bring awareness of possible problematic weeds in the Korean mulberry fields. The survey was conducted in 53 regions, covering approximately $145,925m^2$. Altogether 153 weed species of 37 families were identified, of which 68 were annual, 39 species were biennial and 46 were perennial. The dominance was the highest with Digitaria ciliaris followed by Erigeron annuus, Chenopodium album, Echinochloa crus-galli var.crus-galli, Acalypha australis, Commelina communis etc. Exotic weeds presented 44 species with 28.8% of a total presence, of which Erigeron annuus was the highest, followed by Chenopodium album, Phytolacca americana, Conyza canadensis, Oxalis corymbosa etc. Especially, we should aware Senecio vulgaris, not controlled with glufosinate ammonium SL in the Korean mulberry fields because it was known as atrazine resistance in US, Canada, Germany etc. In the PCA plot, weeds presented in the mulberry fields were divided into two groups, Eclipta prostrata community and Stellaria aquatic community and weed flora of Suwon and Buan were different due to those only presented in Suwon.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.223-245
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• 1983

Nationwide weed survey of paddy rice field conducted in 1981 and 1971 was compared and determined major dominant weed community types distributed by province. Based on the similarity coefficients between 1971 and 1981 the floristic composition based on the degree of dominance was greatly dissimilar while kind of weed flora were not much differed. Degree of dominance were concentrated to perennial weeds in 1981 while these were at animal weeds in 1971. The moat important 10 weed species and their dominance in 1981 were Monochoria vaginalis Presl.(22.2%), Sagittaria pygmaea Miquel(17.5%), S. trifolia L.(9.0%), Poramogeton distinctus Benn.(9.0%), Cyperus serotinus Rottb.(8.5%), Rotala indica Koehne(6.0%), Aneilema japonica Kunth(4.4%), Lindernia procumbens Philcox(3.9%), Eleocharis kuroguwai Ohwi(3.4%) and Ludwigia proarrara Roxb(3.0%), respectively while these for 1971 were R. indica(34.5%), Eleocharia acicularis Roem, et Schult (11.9%), M. vaginalis(11.1%), Cyperua difformis L.(8.7%), Echinochloa crus-galli Beauv.(6.9%), L. procumbens(3.3%), P. distinctus(3.1%), A. Japonica (2.4%), E. kuroguwai(1.8%) and P. hydropiper(1.8%), respectively. Weed occurrence was also closely related with soil type, cropping pattern and cultural practices. Particularly, the occurrence of P. distincrus was negatively correlated with the degree of land utilization. Weed community types dafined by two-dimensional ordination analysis were 11 for Jeonnam province, 9 for Gyeoaggi, Gangweon, Chungbuk and Gyeongnam provinces, 8 for Jeonbuk and Gyeongbuk provinces, 7 for Chungnam province and 4 for Jeju province, respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.19 no.3
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• pp.27-40
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• 1991

For the establishment of district planning in natural parks, vegetationin the most significant point. Consequently, district plan should be made basically under phytosociological investigations. The purpose of this paper is to conserve vegetation in the district planning at natural park(Nam Han San Sung provincial natural park). The result of vegetation survey are as follows : As an actual vegetation 13 communities are recognized. Those are Quercus mongolica-Carpinus laxiflora community, Quercus mongolica-Rhododendron schlippenbachii community, Quercus serrate community, Betula platyphylla var. Japonica community, Quercus dentata community, Quercus mongolica-Pnuus densiflora community, Quercus acutissima community, Robinia pseudo-acacia community, Alnus hirsuta community, Castanea crenata community, Quercus variabilis community, Pinus densiflora community, Pinus rigida community, weed community on cultivated land(Form land), Larix leptolepis reforested land, cut over area and non-vegetation area. The grade of vegetation naturalness was divided into five degrees by characteristics of actual vegetation. I intended to make zoning plan for protection of vegetation with a special attention to the grade of vegetation naturalness and I discussed the necessity of the improvement of existing district plan. District plan was proposed as Fig. 5.

• Korean Journal of Weed Science
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• v.7 no.3
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• pp.265-279
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• 1987

About 140 weed species belonging to 42 families occurring in summer were observed in Ulreung island. The Compositae was the most wildely occurring family covering 27 weed species, followed by 21 species in Graminae, 9 in Polygonaceae, 7 in Leguminosae, and 7 in Labiatae etc. In terms of the lands classified, about 60 species in 26 families were observed in the cultivated and the medical crops grown areas, respectively, and 116 species in 40 families occurred in the non-cultivated land like the vicinity of the cultivated area and 94 species in 34 families in the valley. No. of species and families were much greater in the non-cutivated land than those of the cultivated one. The most dominant weed species in both the cultivated and its vicinity in Ulreung island were Digitaria sanguinalis, followed by Portulaca oleracea, Polygonum hydropiper, Equisetum arvensis, Artemisia princeps, Commetina communis, Setaria viridis in order. Community analysis was done by the method of Toyohara in two cultivated lands such as the general crop land and the medical herb crop grown land, and two non-cultivated areas such as the vicinity of the cultivated land and valley. The cultivated land consisted of the communites of P. hydropiper and Cyperus amuricus, including Bidens tripartita in P. hydropiper community. The medical crop grown land composed of three major communities like P. hydropiper, Amaranthus mangostanus and Sonchus asper in which A. mangostanus and S. media were presented in the ecoton, indicating community being transiting. In the non-cultivated areas like the vicinity of crop land, the communities of Erigeron annuus, P. oleracea, and Oxalis corniculata were dominant, and Dystaenia takeshimana was included in the community of E. annuus and Stellan'a aquatica in P. oleracea community. In the valley, Ranunculus quelpaertensis community was existed in between the communities of Sonchus asper and Plantago asiatica.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.405-411
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• 2010

The phytosociological study was carried out to investigate the structural characteristics of fallow paddy vegetation in Korea. The vegetation data of total 22 relev$\'{e}$s were analyzed by the Zurich-Montpellier school's method. Six syntaxa (1 subassociations and 5 communities) of fallow paddy were recognized: Polygonetosum thunbergii typicum subass. nov. hoc., Aneilema keisak community, Juncus effusus var. decipiens community, Phragmites commuis community, Monochoria vaginalis var. plantaginea community, Typha orientalis community of Polygonetum thunbergii Lohm. et Miyawaki 1962. Detrended correspondence analysis showed that Aneilema keisak community and Monochoria vaginalis var. plantaginea community were negatively correlated with soil total nitrogen. Polygonetosum thunbergii typicum subass. nov. hoc. and Phragmites commuis community was distributed in the soil with low pH.

• The Korean Journal of Community Living Science
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• v.17 no.3
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• pp.89-97
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• 2006

This study was conducted to compare soybean growth and yield and the degree of weed emergence according to no-tillage and conventional tillage system in two different drained paddy fields, loam of Chilgok series and silty clay loam of Deokpyeong series. In both soil conditions, the maturing time of the soybeans by the no-tillage system was two days earlier than that by the conventional tillage system. In the loam of Chilgok series, the stem length of the soybeans in the no-tillage system was 5.7 cm longer than that in the conventional tillage system. The miss-planted rate and diseased plants of black root rot (Calonectria iliacola) in the no-tillage system were 9.2% and 2.8% lower, respectively than those in the conventional tillage system. Also, the nodulation and seed yield in the no-tillage system were 32% and 13% more, respectively, than those in the conventional tillage system. In the silty clay loam of Deokpyeong series, the stem length of the soybeans in the no-tillage system was 4.6cm shorter than in the conventional tillage system. The diseased plants of black root rot (Calonectria iliacola) in the no-tillage system were 4.2% lower than those in the conventional tillage system. Also, no significant difference in the seed yield between the no-tillage and conventional tillage systems was observed. On the other hand, there was a lower occurrence of weed in the no-tillage system than in the conventional tillage system, and the income increased by 19% owing to yield increase and reduced management costs.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.1
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• pp.133-148
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• 2014

In order to investigate community formation ability, herbaceous perennials such as Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne, Pennisetum alopecuroides (L.) Spreng. and Arundinella hirta Tanaka were planted in April 2009 at the levee slope of Gwangju Stream in South Korea. Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. which grew in pots for two years and divided rhizomes of Arundinella hirta Tanaka gathered from fields were employed. Weeds growing on the experiment sites were removed twice a year until 2011 when the plant species were formed into community. Weeds were not eradicated during 2012 and 2013 to observe community sustainability of the species. T-tests on stem numbers and heights in May, July and September were conducted between 2011 and 2012, and between 2012 and 2013. Stem numbers of the five species in 2012 were significantly reduced(p<0.001) compared with those in 2011, which were attributed to weed growth in 2012. Heights of Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne, Pennisetum alopecuroides (L.) Spreng. and Arundinella hirta Tanaka in 2012 were significantly lower than those in 2011(p<0.001), which resulted from weed invasion. Heights of Miscanthus sacchariflorus Bentham in May and July 2012 were significantly decreased compared with those in 2011(p<0.001), however, heights of Miscanthus sacchariflorus Bentham in September 2012 were almost the same as those in 2011(p>0.05). Miscanthus sacchariflorus Bentham was able to compete against weeds in September 2012. Stem numbers and heights of Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. in 2013 were similar to those in 2012(p>0.05). However, stem numbers and heights of Arundinella hirta Tanaka in 2013 were significantly decreased compared with those in 2012(p<0.001). After community formation, Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. were able to maintain its community without weed removal. However, Arundinella hirta Tanaka was unable to establish its community due to the weed growth. Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne are more suitable to stream levee slope environment in terms of community formation and maintenance, stream landscape enhancement and slope erosion control.