• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.2
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• pp.79-83
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• 2005

Rice and weed interference in the paddy field caused by resource competition and allelopathy. Evaluation method of active weed suppressive behavior of rice to weed was developed by eliminating light competition at soil condition. Twenty eight days old rice seedlings (6-7 leaf stage) which was grown at saturated, no drainage pot were clipped above $3\~4cm$ from the soil surface. Weeds seeded around clipped rice stem, named ratoon seeding screening method, showed varietal suppressive difference to Echinochloa crus-galli, Echinochloa crusgalli var. praticola and Monochoria vaginalis. Potential allelopathic rice varieties, Sathi, AC1423 and PI312777 showed better suppressive activity to weed seedling growth than Nonganbyeo and Keumobyeo. Weed suppression of one plant of rice cultivars could be evaluated by the cell size of $2.5\times2.5cm$ at rice clipping of seedling 29 days after rice seeding.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.164-169
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• 2013

Alternatives to commercial chemical herbicide are currently being searched and tested due to the numerous adverse effects of commercially available herbicides to the environment. Barnyardgrass (Echinochloa crusgalli) is an important weed species around the world, especially in paddy rice fields. This study focuses on the favorable effects of mixing pyroligneous acids with commercial liquid herbicides. Seedlings were transplanted and grown under greenhouse conditions. The effect of treatment time or leaf-stage on herbicide-pyroligneous acid efficacies was checked, coupled with isolation and quantification of biochemical compounds. Results revealed that herbicide treatment at early post emergence (2~3 leaf stage) of Echnochloa crus-galli leads to effective control. Both liquid herbicides affected fatty acid, protein, and amino acid syntheses as reflected on their contents. The influence of wood vinegar (WV) or rice vinegar (RV) on these compounds was not thoroughly verified due to lack of information on the pyroligneous products. We observed that mixing WV or RV with BCB (bentazone + cyhalof-butyl) gives more favorable results than BUC (butachlor + clomazone), mixed with WV or RV. The result would indicate the potential of mixing pyroligneous acid in reducing herbicide application rate.

• Korean Journal of Environment and Ecology
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• v.24 no.3
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• pp.264-278
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• 2010

This study was carried out to describe the basic materials of the flora and vegetation for the conservation and management of the Dokdo ecosystem. The vegetation types were investigated by physionomy. 53 taxa of vascular plants were found, including 29 families, 48 genera, 49 species, 1subspecies, and 3 varieties. Among the investigated 53 taxa, it was recorded as follows: 2 Korean endemic plants included Sedum kamtschaticum var. takesimense M.Park and Campanula takesimana Nakai and 6 naturalized plants included Brassica juncea (L.) Czern., Sonchus oleraceus L., Bromus catharticus Vahl, Lepidium virginicumL., Chenopodium album L., and Ipomoea purpurea Roth. In particular, common morning glory (Ipomoea purpurea Roth) was reported for the first time in this survey of Dokdo. Based on physionomy, the main plant communities of Dokdo Island were Aster spathulifolius-Sedum oryzifolium community, Aster spathulifolius-Artemisia Japonica subsp. littoricola community, Fallopia sachalinensis-Cyrtomium falcatum community, Echinochloa crusgalli community, Echinochloa crusgalli var. oryzicola community. The debates have been continuing about a mis-identification of plants. To avoid this debate and manage naturalized and cultivated plants, taxonomist surveys and continual monitoring for the Island are required.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.249-253
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• 1991

Barnyard millet (Echinochloa crusgalli var. frumentacea) has been detected as the best fodder crop in Korea for earlier and/or later season crop. The objective of the study was to examine varieal differences among the varieties introduced from ICRISAT and cultivated in Korea for salt tolerance and green fodder and grain yield under the saline and normal upland soil conditions, IEC 514, IEC 515, IEC 518 and IEC 528 introduced from ICRISAT were relatively highly tolerant to saline soil and with higher green fodder and grain yields, and also were very earlier headed and matured as compared with the Korean local varieties and King.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.4
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• pp.217-224
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• 2001

In order to identify the growth characterization, the yield and chemical composition of Jeju barnyard grass (Echinochloa crusgalli var. fiurnentacea(Roxb) Wight) based on seeding date in Jeju region, seeding carried out the 10-day intervals from March 27 to September 30 in 2000, respectively. Plant height was 143.2 cm, showing the highest on seeding date, April 6 among that of any other seeding date. On the other hand, those of early and late seeding gradually decrease. Plant height was 119.2 an in May 16 seeding. The results of stem diameter, number of withering leaves, number of leaves and fresh weight per plant were similar to those of the plant heights. The yield of fresh, dry matter forage, crude protein and TDN found the highest on April 6 seeding, 63.5 MT/ha, 13.9 MTha, 1.1 MT/ha, and 7.6 MT/ha, respectively. In early and late seeding, the yield was gradually decreased. In seeding May 16, the yield found .38.2 MTIha in fresh forage, 6.2 MTha in dry matter forage, 0.7 MT/ha in crude protein and 3.7 MTha in TDN, respectively. According to delaying the seeding date, March 27 to May 16, the contents of crude protein (from 7.9 to 10.8%), ether extract (from 4.6 to 6.0%), nitrogen free extract (from 45.1 to 46.5%), and TDN (from 54.2 to 60.8%) were gradually increased, respectively. On the other hand, those of crude fiber (from 28.9 to 25.6%) and crud ash (from 13.5 to 11.2%) were decreased. These results showed that April 6 was the optimum seeding date with the sole object of feed production of Jeju barnyard grass under the environmental condition like as atmospheric phenomena and soil in Jeju region. (Key words : Jeju barnyard grass, Seeding date, Forage yield, Chemical composition)

• Journal of Wetlands Research
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• v.10 no.1
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• pp.31-37
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• 2008

A study of the vascular hydrophyte communities was undertaken in the wetlands of Imjado, Shinangun, from March to November, 2006. As a result, the vegetation was divided into 15 communities. Among them, emergent hydrophytes consisted of 9 communities, including Phragmites communis community, Typha angustata community, Paspalum disticum var. indutum community, Sparganium erectum community, Oenanthe javanica community, Echinochloa crusgalli var. crusgalli community, Juncus effusus var. decipiens community, Aneilema keisak community and Persicaria thunbergii community, floating hydrophytes 1 community Trapa japonica community, free-floating hydrophytes 2 communities including Lemna paucicostata community and Spirodela polyrhiza community, and submergent hydrophyte 2 community, including Myriophyllum verticillatum community and Potamogeton distinctus community. These results were considered that the wetland of Imjado was characterized by the typical structure of aquatic plant ecosystem.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.203-215
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• 1998

The weed vegetion of the rice fields in south Korea was researched in terms of syntaxonomy and synecology. Total 186 releves were analyzed by the Zurich-Montpellier school's method. 10 syntaxa were recognized: Stellario-Alopecuretum amurensis ass. nov. hoc loco, Alopecuro-Ranunculetum scelerati Miyawaki et Okuda 1972, Hemistepto-Capsellietum bursa-pastoriae ass. nov. hoc loco, Oryza sativa-Echinochloa crusgalli community, Sagittario-Monochorietum plantaginea Miyawaki 1960, Cyperus iria community, Hyperico-Juncetum decipiens ass. nov. hoc. loco, Spirodela-Lemna paucicostata community, Lemno-Salvinetum natans Miyawaki et J. Tuxen 1960. The Oryzo-Echinochloion oryzoides Bolos et Masclans 1955 and the Alopecurion amurensis Miyawaki et Okuda 1972 are representative of the summer annual plant community and the winter annual plant community. It was emphasized that syntaxonomical and synecological study on the ruderal and segetal weed vegetation in Korea should be accomplished in consideration of bioclimatic condition of summer monsoon climate of Korean Peninsula.

• Korean Journal of Weed Science
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• v.11 no.3
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• pp.178-186
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• 1991

This study was conducted to evaluate the major weeds occurred in direct seeded rice and their compition with rice, and to establish the effective weed control method. The important weeds occurring in dry direct seeded rice were Echinochloa crusgalli, Cyperus amuricus, Rorippa islandica, etc. Among them, Echinochloa crusgalli was the most dominant weed species. In view of the Simpson's dominance index, the maximum number of the weeds was observed at 30 days after seeding, showing 0.26, but decreased as the time passed. In other hand, Simpson's dominance index of weed dry weight increased from 0.09 at 15DAS(days after seeding) to 0.28 at 60DAS indicating that particular weed such as barnyardgrass was dominating the fields. The plant height and the tiller number of rice in the dry direct seeded rice were not greatly affected by the time and duration of competition with weeds, but rice yield was greatly influenced by them. The yield reduction was observed when compition between rice and weeds were initiated at 20 to 40 DAS till the harvesting time. The highest weed control efficacy was observed at the treatment of systematic herbicide application such as soil applied Butachlor followed by Mefenacet/Bensulfuron-methyl/Dymron at 30 DAS after seeding, and soil applied Dimepiperate/Bensulfuron-methyl mixture as a preemergence type gave also an excellent control.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1469-1473
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• 2010

Influences of alrylamino (R) substituents on the herbicidal activity ($pI_{50}$) of 1-(4-chloro-2-fluoro-5-propargyloxypheny)-3-(R)-thiourea analogues (1 ~ 35) against the barnyard grass (Echinochloa crusgalli) in the pre-emergence step were discussed quantitatively using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) as the three dimensional quantitative structure-activity relationship (3D-QSAR) method. The statistically most satisfactory CoMFA models for the herbicidal activity against the barnyard grass had the better predictability ($r^2{_{cv.}}$) and correlativity ($r^2{_{ncv.}}$) than those of CoMSIA models. The optimized CoMFA model 1($r^2{_{cv.}}$ = 0.531 & $r^2{_{ncv.}}$ = 0.931) with the sensitivity to the perturbation (${d_q}^{2'}{dr^2}_{yy'}$ = 1.081) and the prediction ($q^2$ = 0.475) produced by a progressive scrambling analyses were not dependent on chance correlation. And statistical qualities with the atom based fit alignment (AF) were slightly higher than those of the field fit alignment (FF). According to the optimized CoMFA model 1, the contribution ratio (%) of the steric field (76.9%) on the herbicidal activity of the Thioureas was three-fold higher than that of the electrostatic field (20.1%) and the hydrophobic field (3.0%) had the least influence. A steric favor group is on the vicinity of the nitrogen atom in alrylamino (R) substituent, and a steric disfavor group is on the outer side of alrylamino (R) substituent. Thus, as the size of alrylamino (R) substituent increases, so does the herbicidal activity of the substituent.

• Korean Journal of Weed Science
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• v.6 no.1
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• pp.25-32
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• 1986

This experiment was conducted to evaluate effect of various hormones on callus induction, and on plantlet formation on various media, and to detect of Londax [Methyl 2-[[[[[(4,6-dimethoxy pyrimidin-2-yl) amino] carbonyl] amono] sulfonyl) methyl] benzoate] and Basta[Ammonium-(3-amino-3-carboxy-propyl)-methyl phosphinate] on callus growth and reaction of succinate dehydrogenase in callus against TTC, using various species such as Eleocharis kuroguwai, Cyperus serotinus, Oryza sativa (samgangbyeo) and Echinochloa crusgalli P. Beauv. var. caudata Kitagawa. The optimal levels of 2,4-D in MS medium seems to be different among species tested, 2.0 ppm for rice and E. crusgalli, 1.0 ppm for Eleocharis kuroguwai, and 4.0 ppm for C. serotinus derived callus from shoot-tip. In case of combination of 2,4-D with BA, 1.0 plus 0.3 ppm appeared the most appropriate level to induce callus from rice and E. kuroguwai, and I.0 plus 0.1 ppm for C. serotinus and E. crusgalli. When 2,4-D treated with TIBA, 1.0 plus 0.5 ppm appeared the most appropriate rates to induce callus derived from seeds of rice, E. crusgalli, seeds of C. serotinus and E. kuroguwai, 1.0 plus 0.3 ppm for shoot-tip of C. serotinus. Positive reaction of succinate dehydrogenase against TTC was observed regardless of calli and herbicides tested, indicating that they all are alive, and these herbicides were not able to kill the calli tested within the short period of time 20 hrs treatment. Regardless of plant species used, the rate of plantlet formation from callus was very low. However, some plantlet formed from E. crusgalli at 0.8 ppm of 2,4-D plus 8.0 ppm of kinetin, and from E. kuroguwai at 1.6 ppm of 2,4-D plus 16.0 ppm of kinetin, showing effectiveness of 2,4-D with kinetin mixture treatment. No callus was induced from C. serotinus treated with Basta from $10^{-6}M$ to $10^{-3}M$. In general, rice was the least susceptible to Basta among plant species tested, followed by E. crusgalli, and E. kuroguwai. In Londax treatment, rice showed the least inhibition rate in callus growth. Callus was induced from rice even at $10^{-3}M$ of Londax. However, $10^{-3}M$ of Londax completely inhibited callus induction from the test species. Rice showed most tolerant to both herbicides, indicating the existence of different responses among plant species.