• Korean Journal of Weed Science
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• v.10 no.3
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• pp.197-201
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• 1990

Emergence and growth of Potamogeton distinctus, Eleocharis kuroguwai, and Sagittaria pygmaea were examined at soil temperatures of 12, 15, 18, 22, 26, and $30^{\circ}C$ and 3 planting depth conditions. Optimum soil temperatures for emergence were 15-$22^{\circ}C$ 22-$26^{\circ}C$, and 18-$26^{\circ}C$ for P. distinctus, E. kurogueai, and S. pygmaea, respectively. Emergence was delayed and growth became poor in three species as planting depths were increased and this trend was more significant in E. kuroguwai.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.365-370
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• 2009

The aim of this study was to investigate the vegetation types of Minarimot, in Jeju Islands. The vegetation types were classified by the Z-M school method and cluster analysis. The vegetation in Minarimot was classified into 6 communities and 2 subcommunities: Persicaria thunbergii-Isachne globosa community (vegetation type: A), Scirpus tribangulatus-Eleocharis manillata var. cyclocarpa community (B) (Aneilema keisak subcommunity (B-1) and Caldesia parnassifolia-Potamogeton distinctus subcommunity (B-2)), Eleocharis kuroguwai community (C), Phragmites communis community (D), Scirpus tabernaemontani community(E) and Typha orientalis community (F). These communities were grouped into three main categories according to cluster analysis. The community (A) established at the edge of the wetland which has the driest condition was distinguished as Group I, while the community (B) emerged in the submerged zone was distinguished as Group III. The Group II was designated as the communities (C, D, E, F) between Group I and III, whose communities were occasionally submerged. The result of principal coordinate analysis (PCoA) appeared that the different vegetation established along the wetland were depending on water environment such as water depth and the period submerged.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.1
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• pp.61-69
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• 1977

The affect of perennial weeds to rice yield and rice growing was evaluated. Rice heading date was shortened 1-4days and rice culm length was shortened 5-10cm in heavy weed growing condition. The ratio of yield reduction were about 50% in Cyperus serotinus, about 57 in Potamogeton distinctus in both rice varieties and about 60% of Eleocharis kuroguwal in heavy perennial growing condition.

• 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.3 no.1
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• pp.50-56
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• 1983

A study was conducted to evaluate the weed population as affected by repeated application of fertilizers for 15 years (nonfertilized, PK, NK, NPK, NPK+Compost, NPK+Straw and NPK+lime). Alopecurus aequalis authority did not grow at all without P application and lime reduced the population of A. aequalis. Total number of weeds were the largest at 5-10cm soil layer and increased by application of compost and straw. Monochoria vaginalis dominated in NPK+compost and NP plot. Scirpus hotarui dominated in NPK+straw. Both Eleocharis kuroguwai and Potamogeton distinctus dominated in nonfertilized plot. Numbers of M. vaginalis and S. hotarui were larger low pH 6 while that of E. kuroguwai and P. distinctus at pH 6 to pH 7. Incidence of M. vaginalis and S. hotorui was great at pH's lower than 6, while E. kuroguwai and P. distinctus favored pH's ranging from 6 to 7.

• Korean Journal of Weed Science
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• v.4 no.2
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• pp.130-134
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• 1984

This experiment was conducted to know critical sowing depth and emergence day under different sowing depth at Crop Experiment Station, Suweon, in 1982. Tested weed species were Sagittaria pygnaea, Eleocharis kuroguwai, Cyperus serotinus and Potamageton distinetus, sowing depth of weeds were 5cm, 10cm, 15cm, 20cm and 25cm Critical emergence sowing depth of S. pygnaea, E. kuroguwai was 15cmand C. serotinus was 20cm sowing depth while P. distintus was 25cm sowing depth. Average emergence days under 5cm sowing depth for E. kurogwai, S. pygmaea, P. distintus and C. serotinus was 27.8 days, 14.1 days, 13.6 days and 7.3 days. While, relationships between sowing depth and day to emergence was positively correlated. Gernination percent of weeds under Critical emergence sowing depth, S. pygmaea, E. kurogwai and, P. distinctus was 57%, 67%, 80%, but C. serotinu.s was all died.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.407-413
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• 2011

This study was analyzed and investigated to evaluate ecological distribution of medicinal plants in Miho Stream of Korea. Totality 463 taxa of vascular plants were appeared in lower part of Miho Stream. Medicinal plants were distributed 253 taxa, which were 54.6% of the total vascular plants appeared. Medicinal plants of official drug compendium(Korean pharmacopoeia) were 85 taxa. Medicinal plants were distributed most of the forest area, and followed field surrounding, stream surrounding and paddy surrounding respectively. The distribution of life form hemicryptophyte was the most frequent. Plant community of appearing area of medicinal plants was classified into Salix koreensis, Phragmites japonica, Echinochloa crusgalli, Artemisia selengensis, Miscanthus sacchariflorus, Setaria faberii, Panicum dichotomiflorum, Bidens frondosa, Humulus japonicus, Monochoria vaginalis var. plantaginea, Eleocharis kuroguwai, Erigeron acris, Pinus densiflora, Pinus rigida, Quercus acutissima, Quercus serrata, Robinia pseudoacacia and Castanea crenata community. Medicinal plants in plant communities that occur frequently were Humulus japonicus, Corylus heterophylla and Liriope spicata.

• Mycobiology
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• v.43 no.3
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• pp.231-238
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• 2015

A total of 4 aquatic plants, Eleocharis kuroguwai Ohwi, Hydrocharis dubia Backer, Salvinia natans All., and Zizania latifolia Turcz., were sampled from representative two wetlands of South Korea. A total of 38 endophytic fungal strains were isolated from aquatic plants native to the Daepyeong wetland, and 27 strains were isolated from the Jilnal wetland. The internal transcribed spacer regions of fungal isolates were sequenced and a phylogenetic analysis was performed. In addition, endophytic fungal diversity from each wetland and host plant species was deduced. A total of 25 fungal genera were purely isolated, and 16 fungal genera were isolated from each of the two wetlands. Commonly isolated genera from both wetlands were Aspergillus, Cladosporium, Clonostachys, Fusarium, Leptosphaeria, Penicillium, and Talaromyces. This study revealed that fungal diversity varied with environmental conditions and by host plant in representative two wetlands.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.1
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• pp.20-23
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• 1976

Distribution of underground organs of perennial weeds in soil and ecological control measure were evaluated. Tubers of Cypers serotinus and Sagittaria pygmaea were mostly presented in a shallow depth of 0 to 5cm, however, Potamogeton distinctus's bulbs and Eleocharis kuroguwai's tubers were distributed in the soil at 10 to 20cm. A 20cm autumn plowing was, to some extent, effective to reduce Potamogeton distinctus. The herbicide, avirosan at 3kg/10a alone, was extremely effective in controlling Potamogeton distinctus.

• Korean Journal of Weed Science
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• v.16 no.4
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• pp.264-281
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• 1996

As a consequence of wide use of herbicides, Eleocharis kuroguwai Ohwi became a dorminant problem weed for rice cultivation in Korea. To understand the establishment of the weed, experiments on physio-ecological characteristics were carried out sprouting and occurrence, the results could be summarized as follows: Sprouting percentage remained 68 to 73% until the time of field emergence, indicating many of the them are still dormant. The proportion of the dormant tubers were greater for the smaller than the bigger tubers. Apical dominance was apparent in sprouting, with 84% of tuber sprouted from only one of the apical buds. Tubers sprouted from 2 or 3 buds were less than 20%, and were mostly from the bigger tubers. When the shoot growth was compared, by controlling the others, ones from apical and the next 3 buds showed similar vigorous growth, but the later ones showed poorer growth. For the longevity of tubers, deep soil storage appeared to be better than storage in temperature controlled room to 2~$3^{\circ}C$. Emergence of E. kuroguwai was better in clay soil than in sand, and the possible depth for emergence in clay soil appeared to be up to 21cm, but was 15cm in sand. When tubers were exposed to salt solutions before emergence tests, E. kuroguwai appeared to be much sensitive to salts than S.planiculmis. Among the tubers formed in previous year, 12.7% remained still viable until the end of next crop season, but with relatively strong dormancy. The first emergence was about 10 days after planting at ordinary cropping seasons, and the days to the maximum shoot number stage were 60~90 from planting. The duration was extended at early transplanting, and shoot number, leaves per shoot, and tubers developed per plant were also greater at early plantings. The 6th order offshoots were developing when E. kuroguwai was planted at early season. When planted at later seasons, generation and the number of offshoots was reduced planted at early season. When planted at later seasons, generation and the number of offshoots was reduced and the number of tubers, runner and rhizome lengths was also reduced.