• Korean Journal of Agricultural Science
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• v.33 no.2
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• pp.123-127
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• 2006

This study was carried out to compare growth and yield performance for soil conditions at the Maize Genetics and Breeding Lab. in Chungnam National University. The waxy hybrid corn in the drained soil of paddy field showed higher fresh yield per 10a and 100-kernel weight per plant than control. The average dry yield of drained and drainless soil were 804kg/10a and 498kg/10a compared with a control (751kg/10a), respectively. The waxy hybrid corn in the drained soil also had better good stand and stay green characteristics than drainless soil condition, and showed moderately resistance to water stress and weed. Vegetational feature of weeds was characterized as the prevalence of Acalypha auatralis, Echinochloa crus-galli, Persicaria hydrpopiper in drained paddy soil and Persicaria hydrpopiper, Acalypha auatralis, Echinochloa crus-galli in drainless paddy soil, and Echinochloa crus-galli, Acalypha auatralis in upland soil.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.1-12
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• 1999

Herbicidal activities of newly synthesized experimental compound, KSC-13906 [Erythro N-{(4,6-dimethoxy pyrimidin-2-yl)aminocarbgnyl}-2-(2-fluoro-1- hydroxy-n-propyl)benzenesulfonamide, US Patent 5,461,025], were investigated in greenhouse and field for development as a paddy herbicide. KSC-13906 exihibited excellent weeding effects and selectivity to rice under submerged paddy condition in geenhouse. At the application rate of $2.5{\sim}5$ g ai/ha treated on surface of water, KSC-13906 effectively controlled three annual weeds such as Echinochloa crus-galli var. oryzicola. Scirpus juncoides, and Monochoria vaginalis as well as five perennial weeds such as Cyperus serotinus, Sagittaria pygmaea, Eleocharis kuroguwai, Potamogeton distinctus, and S. trifolia. However, there was no effect on Aneilema keisak and Lindernia procumbens. Especially, KSC-13906 effectively controlled Echinochloa crus-galli var. oryzicola at growth stages ranging from pre-emergence to 3-leaf stage. Antagonistic interaction was found between pyrazosulfuron-ethyl and mefenacet, but not between KSC-13906 ana mefenacet. KSC-13906 had high selectivity to transplanted rice, but caused phytotoxic effect on direct-seeded rice when treated before 3-leaf stage. Herbicidal activity of KSC-13906 on the Echinochloa crus-galli var. oryzicola was 7-folds greater than that of pyrazosulfuron-ethyl in terms of relative dose ratio of the herbicides. These results suggest that KSC-13906 possesses selective herbicidal potency in rice.

• Applied Biological Chemistry
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• v.47 no.3
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• pp.351-356
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• 2004

Holographic quantitative structure activity relationships (HQSAR) as 2D QSAR between the herbicidal activities against root and shoot of rice plant (Orysa sativa L.) and barnyardgrass (Echinochloa crus-galli), and structures of A=3,4,5,6-tetra-hydrophthalimino, B = 3-chloro-4,5,6,7-tetrahydro-2H-indazolyl and C = 3,4-dimethylmaleimino substituents in 1-(5-methyl-3-phenylisoxazolin-5-yl)methoxy-2-chloro-4-fluorobenzene derivatives were studied and discussed. The statistical results of four HQSAR models for the herbicidal activities against root and shoot of the two plants showed the best predictability of the herbicidal activities based on the cross-validated $r^2\;_{cv}\;(q^2=\;0.760{\sim}0.924)$, non cross-validated conventional coefficient $(r^2\;_{ncv}\;=\;0.868{\sim}0.970)$ and PRESS values $(0.123{\sim}0.261)$. The results indicated that the qualities of HQSAR models for barnyardgrass were slightly higher than that of rice plant. And also, the predictability of HQSAR models were higher $(q^2\;=\;HQSAR\;>\;CoMFA)$ than CoMFA but the conventional coefficients of HQSAR models lower $(r^2\;=\;HQSAR\;<\;CoMFA)$ than CoMFA. Moreover, from the contribution maps, it was founded that the selectivity between the two plants depends upon the 2-fluoro-4-chloro-5-alkoxyanilino and $R_3$ substituent on the C-phenyl ring. These features suggest where to modify a molecular structure in order to improve its selective of herbicidal activities against barnyardgrass.

• The Korean Journal of Pesticide Science
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• v.7 no.2
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• pp.75-82
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• 2003

We discuss that the growth inhibition activities against root and shoot of rice plant (Oryza sativa L.) and barnyard grass (Echinochloa crus-galli) by N-phenyl-3,4,5,6-tetrahydrophthalimide (A) and N-phenyl-3,4-dimethylmaleimide (B) derivatives with changing substituents can be explained and predicted using comparative molecular field analyses (CoMPA) method. And the results show that the cross-validation value, $q^2$ at three components and Pearson correlation coefficient, $r^2$ were rice plant: shoot; $r^2=0.987$, $q^2=0.387$ & root; $r^2=0.923$, $q^2=0.307$ and barnyard grass: shoot; $r^2=0.902$, $q^2=0.535$ & root; $r^2=0.900$, $q^2=0.450$, respectively. In addition, The activities of unknown compounds were predicted by CoMFA method. From the contour map of (A) derivatives, the selective factors to remove barnyard grass takes positive charge on the benzylic carbon atom (C27), negative charged carbon atom (C29) of meta position and steric bulky groups on the cyclic imino ring (C7-C8).

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.71-77
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• 2011

This study was conducted to predict the yield loss of red pepper and to determine the economic weed thresholds levels for red pepper cultivation field from competition with the most serious weeds, Echinochlor crus-galli (L.) P. beauv. (barnyard grass) and Chenopodium album L. (goosefoot) in Youngyang of Korea. Crop yield as a function of weed density was predicted by using a rectangular hyperbola, and their economic threshold levels were determined by using the equation developed by Cousens (1987). The red pepper yield loss models of weeds were predicted as y=317.0 kg/ (1+0.1707x), $R^2$=0.895 in E. crus-galli and y=323.2 kg/(1+0.2900x), $R^2$=0.896 in C. album L.. Economic thresholds calculated using Cousens' equation was negatively related with the competitiveness of weed. Economic thresholds of each weed were calculated as 6.5 plant $100m^{-2}$ in E. crus-galli, and 3.7 plant $100m^{-2}$ in C. album L..

• Proceedings of the Korean Society of Crop Science Conference
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• 2003.05a
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• pp.69-69
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• 2003

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.273-282
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• 1988

The seventeen barnyardgrass [Echinochloa crus-galli (L.) Beauv.] accessions, which were collected national-widely in 1986 and selected two times through 1987, were experimented at 1988. To study the degree of ecological variations of the collected accessions of native barngardgrass species as a weed, the experiment was conducted with Wagner pots in size of 1/5000a and under P.E. film house. Among 57 characters, 100 grains weight, rate of tiller increase from transplanting to 30 days, the number of the maximum tillers and rate of dry weight increase from 15 DAS to 22 DAS were become intra-specific variarions as higher coefficient of varation than 30%, the size of the first leaf, fresh weight and dry 22 seedlings, rate of productive tiller, panicle number and tillering divergence made intra-specific variations as more and less C. V. than 25%, while the required days upto heading since seeding at June 6. rate of fresh/dry weight and plant height of 22 days old seedling made intra-specific variations as the coefficient of variation of about 50%. Among the attributes the color in leaf, leaf sheath, mid-ribs, node, spike, grain, and plant type, length of leaf marginal tooth, grain shape, purple bend on leaf were seemed useful to indentify the accessible specific.

• Korean Journal of Weed Science
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• v.10 no.2
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• pp.109-113
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• 1990

In order to determine selective mode of action of naproanilide between rice and paddy weeds, absorption and translocation of $^{14}C$-naproanilide in rice, Echinochloa crus galli, Cyperus serotinus, and Sagittaria pygmaea were studied, Rice plant and Echinochloa crus-galli absorbed less amount of $^{14}C$-naproanilide than Sagittaria pygmaeo and Cyperus serotinus. Less amount of $^{14}C$-naproanilide was translocated into shoots and translocation rate was slower in rice and Ecl:inochloa crzis-galli than that of Sagittaria pygmaea and Cyperars serotinus. Also, 30-40% of $^{14}C$-naproanilide was distributed at tubers of Sagittaria pygmaea and Cyperus serotinus, which explained that higher amount of $^{14}C$-naproanilide was absorbed from tubers. $^{14}C$-naproanilide was gradually decreased in all plant species and finally more radioactivity was determined in Sagittaria pygmaea and Cyperus serotinus than in Echinochloa cars-galli and rice plant after $^{14}C$-naproanilide treated plants were transferred to Kasugai solution.

• Journal of Wetlands Research
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• v.5 no.2
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• pp.43-55
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• 2003

Vegetation structure was investigated in the Hyeonchang wetland and its watershed around the Nakdong-gang, Changryeong-county, Gyeongsangnamdo, Korea. from May to August, 2001. The vegetation type of the Hyeonchang wetland was classified into 12 communities based on the actual vegetation map: Phragmites communis community, Zizania latifolia community, Phragmites communis - Persicaria perfoliata community, Salix koreensis community, Persicaria perfoliata - Phragmites communis community, Spirodela polyrhiza community, Persicaria perfoliata community, Cyperus amuricus community, Cyperus amuricus-EchinochJoa crus-galli var. frumentacea community, Phragmites communis-Zizania latifolia community, EchinochJoa crus-galli var. frumentacea community, and Persicaria maackiana community. Among them, Phragmites communis community was the largest (4.3 ha, 24%). The dominant vegetation type were Phragmites communis community, Echinochloa crus-galli var. frumentacea-Persicaria maackiana community, and Cyperus amuricus subcommunity based on the phytosociological method. The vegetation type of the Hyeonchang wetland watershed was classified into five communities based on the actual vegetation map: Pinus densilflora community, Pinus rigida community, Pinus densiflora-Quercus acutissima community, Pinus densiflora-Larix gmelini var. principis-ruprechtii community, and Populus tomentiglandulosa community. Among them, Distribution area of Pinus densiflora community was largest (399.3 ha, 61.8%). And the degree of green naturality of the Pinus densiflora community was 7 and 8 degree.

• Weed & Turfgrass Science
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• v.3 no.3
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• pp.183-189
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• 2014

The genus Echinochloa (L.) P. Beauv. comprised of approximately 30-40 species in the tropical and warm temperate regions of the world, including numerous interspecific and intraspecific types which make the genus difficult to identify. As an attempt to identify the species within the genus easier, the taxonomy of the genus Echinochloa, Poaceae in Korea was reviewed on the basis of sequencing data derived from nuclear ribosomal DNA internal transcribed spacer (ITS) and external transcribe spacer and chloroplast DNA trnL intron, trnL-F intergenic spacer and matK regions using a total of 46 accessions representing all the species in Korea. The results of maximum parsimony found separate lineage comprised of E. colona and E. frumentaceae which are not Korean species, but no resolution within Korean Echinochloa species, supporting the suggestion of Yamaguchi group that E. crus-galli, E. oryzoides, and E. esculenta should be considered to belong to the same species. However, the relationship between these three species and the other species, i.e. E. oryzicola should be better understood with more detail studies.