• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.3
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• pp.49-68
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• 2021

This study was to carried out to survey and analyse the vascular plants of Mt. Jangsan, Busan Metropolitan City, South Korea. The vascular plants were surveyed from June to October, 2019. The numbers of vascular plants in this site were 497 taxa and comprised of 106 families, 306 genera, 454 species, 7 subspecies, 29 varieties, 5 forms and 2 hybrids. The planted species were 16 taxa including Ginkgo biloba, Cedrus deodara, Zea mays and so on. In this study, 309 taxa were identified, including Selaginella rossii, Cyrtomium falcatum, Cephalanthera falcata and so on. The rare plants were 4 taxa including Hololeion maximowiczii(EN), Ottelia alismoides(LC), Iris ensata Thunb. var. spontanea(LC) and Sagittaria trifolia(DD). All rare plants were found in Jangsan Wetland. The Korean endemic plants were 9 taxa including Populus × tomentiglandulosa, Hemerocallis hakuunensis, Hosta minor and so on. The floristic target species were totally 53 taxa, which were 2 taxa of grade IV, 11 taxa of grade III, 6 taxa of grade II and 34 taxa of grade I. The alien plants were 58 taxa including Rumex crispus, Ipomoea purpurea, Helianthus tuberosus, Vulpia myuros and so on.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.2
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• pp.67-90
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• 2024

The purpose of this study is to present the ecological data for conservation and management of three wetlands by surveying the vascular plants in Ganam reservoir, Ahnshim wetland and Jeomsae swamp. The whole taxa of vascular plants were 376 taxa including 90 families, 252 genera, 341 species, 7 subspecies, 24 varieties, 2 forms, 1 hybrid and 1 cultivar, and the planted species were 66 taxa including Ginkgo biloba and so on. The rare plants were 7 taxa including Euryale ferox(VU), Aristolochia contorta(LC), Koelreuteria paniculata(VU), Sagittaria trifolia(DD), Hydrocharis dubia(LC), Ottelia alismoides(LC) and Sparganium stoloniferum(VU). The Korean endemic plant was 1 taxon of Lespedeza maritima. In total, there were 21 taxa of floristic target species including 1 taxon of garde V, 2 taxa of grade IV, 6 taxa of grade III, 5 taxa of grade II and 7 taxa of grade I . The hydrophytes were 51 taxa including 36 taxa of emergent species, each 6 taxa of floating-leaved and submerged species and 3 taxa of free-floating species. The invasive alien plants were 79 taxa including 75 taxa of naturalized plants and 4 taxa of casual alien plant. The ecosystem disturbing species 6 taxa including Sicyos angulatus, Ambrosia artemisiifolia, Lactuca seriola, Symphyotrichum pilosum, Paspalum distichum and Humulus scandens.

• Korean Journal of Weed Science
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• v.12 no.1
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• pp.8-15
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• 1992

Arrowhead (Sagittaria trifolia L.), a perennial weed dominant in paddy field, is considerably difficult to control by herbicides. The investigation on the effects of environmental factors on emergence of arrowhead tuber can aid for controlling this weed. The results exmined were as follows : From the results of emergence characteristics at different levels of temperature, arrowhead tuber could germinated at 15$^{\circ}C$-40$^{\circ}C$. The optimal temperature for basal emergence was ranged from 25 to 30$^{\circ}C$. Basal emergence at 15$^{\circ}C$ and 20$^{\circ}C$ began at 56 and 12 days after tuber plantation, respectively and were later than those at the optimal temperature. At the different levels of shading, all the tested tubers could emerged. The days required for basal emergence at 25% and 50% shading plots were shorter than those at 70%, 80% and non-shading plots. The basal emergence was more effective under blue and clear films than any other phyto-selective materials. Some of arrowhead tubers could not emerged under green, red and yellow films. On the soil pH, the basal emergence was best at soil pH 6.0 and 7.0. At soil pH 4.0, 5.0 and 8.0, the required days for emergence were longer than those at soil pH 6.0 and 7.0 and some of tubers could not emerged. Arrowhead tubers more then 0.5 g showed the shorter shooting days than those less than 0.5 g. Tubers were able to emerge at water depth ranging from 0 to 20 cm. At 3 cm and 5 cm water depth, the required days for basal shooting were shorter than those at any other levels of water depth. The emergence of basals was best at molding depth of 0 cm, and the rates at 3 to 5 cm of plantation depth were decreased. At 10 cm plantation depth, the shooting rate was significantly decreased.

• Korean Journal of Weed Science
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• v.8 no.2
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• pp.158-163
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• 1988

Several factors affecting emergence and tuber formation of lowland perennial weeds were studied at the Yeongnam Crop Experiment Station in 1988. Period of tuber germination start to final tuber varied by species. Eleocharis kuroguwai and Sagittaria trifolia required longer than 10 days at $30^{\circ}C$ for this while Cyperus serotinus and S. pygmaea needed about 4 days. Application of gibberellic acid shortened this period while Uniconazole application delayed. E. kuroguwai and C. serotinus had ability to emerge under 20cm depth placement. However, S. trifolia could not emerge under 15cm depth. All species decreased their growth with increase in planting depth. E. kuroguwai had least correlated between dry matter production and tuber formation. Clipping of above ground part negatively related with tuber formation eventhough the effect of clipping time was differed by species. The most critical clipping time was 60 days after eremergence (DAE) for E. kuroguwai and 90 DAE for C. serotinus. Covering of colored polyethylene film was also related with tuber formation with varing effects. In general, the order of effectiveness for tuber formation were black. orange. blue and red. Application of Uniconazole and Pachlobutrazol effectively controlled the formation of tuber of E. kuroguwai and this effect enhanced by early application.

• Weed & Turfgrass Science
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• v.7 no.3
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• pp.201-208
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• 2018

This study was conducted to investigate the occurrence and distribution of herbicide resistant weeds at rice fields in Chungnam province of Korea in 2017. Herbicide-resistant weeds occurred in 64,782 ha, which comprise 47.0% of the total paddy field area of Chungnam province. The infested area of herbicide resistant weeds was estimated in Seosan-si (11.9%), Nonsan-si (11.1%), Dangjin-si (10.9%), Boryeong-si (9.2%) and Asan-si (7.8%). The most dominant herbicide resistant weeds in rice fields were Monochoria vaginalis, followed by Lindernia dubia, Schoenoplectus juncoides, Echinochloa oryzicola, Cyperus difformis and Sagittaria trifolia. Herbicide resistant M. vaginalis, L. dubia, and S. juncoides occurred throughout Chungnam province, and herbicide resistant S. trifolia was only found in Dangjin-si. Compared with the 2011 survey, the infested area of herbicide-resistant weeds decreased, but the incidence rates were similar. The herbicide rotation with different modes of actions across growing seasons is recommended to control herbicide-resistant weeds in the infested fields. It is necessary to monitor herbicide resistance regularly and conduct integrated herbicide resistance management in this area.

• Korean Journal of Weed Science
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• v.32 no.3
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• pp.188-194
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• 2012

Field experiments were conducted to investigate the competition relationships of main paddy weeds with transplanted rice grown in paddy conditions. Data were used to predict crop yield as a function of weed density using a rectangular hyperbola model and determine weed economic threshold (ET) levels. The rectangular hyperbola (equation 2) was fitted to rice yield to estimate weed-free rice yield ($Y_o$) and weed competitivity (${\beta}$). Its competitivity for M. vaginalis was 0.0007445, 0.0005713, 0.000988 and 0.0008846 in Daejeon, Suwon, Iksan and Naju, respectively. The competitivity at harvest represented by parameter ${\beta}$ ranged from 0.001611 in Naju to 0.002437 in Iksan for S. trifolia. The ET levels of main paddy weeds in machine transplanted rice cultivation were well estimated based on the herbicides applied and its application cost. Therefore, our results can be used to support decision-making on herbicide application for weed management in transplanted rice cultivation.

• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.119-125
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• 1998

A nation-wide fact-finding survey was done to provide the basic information for establishing the rational weed control scheme in paddy rice. A total of 445 respondents including 273 farmers and 172 pesticide dealers was involved in this survey. Dominant weeds in rice paddy field were Echinochloa crus-galli, Eleocharis kuroguwai, Sagittaria pygmaea, Sagittaria trifolia, etc.. Preferred herbicides widely used by farmners were ranked in the following order; butachlor 5GR, pyrazosulfuron-ethyl + molinate 5.07GR, molinate + cinosulfuron 5.08GR, meanwhile, those recommended by pesticide dealers were; pyrazosulfuron-ethyl + molinate 5.07GR, molinate + cinosulfuron 5.08GR, and butachlor 5GR. The guidelines to choose the preferred herbicides was primarily based on the experience, which was occupied about 45%. Approximately 56% of the farmers followed the recommended herbicide dosage and 43% of them applied the herbicides before weed germination (pre-emergence treatment). In addition, most farmers applied herbicides at least two times with systematic application schedule. Application method of granular formulation was broadcasting by hand, while that of sprayable ones was by high-pressure sprayer. Some farmers answered that they had experienced phytotoxicity in the crop by applied herbicides, of which higher experience was observed from the farmers who applied by high-pressure sprayer. It was analyzed significantly that the feasible herbicides to cause phytotoxicity in rice at farmer's level were butachlor 5GR, esprocarb + pyrazosulfuron-ethyl 5.07GR and bensulfuron-methyl + molinate 5.17 GR.

• Weed & Turfgrass Science
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• v.2 no.4
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• pp.352-357
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• 2013

A survey was performed to investigate major paddy field weeds and frequently used herbicides in Gyeonggi province, Korea in order to establish a system to efficiently control herbicide-resistant weeds. The dominant paddy field weeds included Echinochloa spp. (22%), Eleocharis kuroguwai (14%), Sagittaria trifolia (13%), Scirpus juncoides (12%), Monochoria vaginalis (9%) and Sagittaria pygmaea (7%), and the most widely used herbicides were butachlor 33% CS (25%), benzobicyclon + fentrazamide + imazosulfuron 11.5% SC (9%), cyclosulfamuron + mefenacet 22.2% SC (9%), butachlor 5% GR (6%), and oxadiazon 12% EC (6%) in Gyeonggi province, Korea. Many paddy rice growers considered S. juncoides, M. vaginalis, S. pygmaea and C. difformis as herbicide-resistant weeds. An extensive research deserves to be conducted to monitor occurrence of herbicideresistant paddy weeds in Gyeonggi province, Korea.

• Korean Journal of Weed Science
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• v.6 no.2
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• pp.134-145
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• 1986

The experiment was crried out to evaluated the herbicidal properties of bensulfuron methyl [methyl 2-[[[[[(4, 6-dimethoxy pyrimidine-2yl) amino] carbonyl] amino] sulfonyl] methyl] benzoate]. No phytotoxicity was observed when bensulfuron methyl was applied at 3 and 6 g a.i./ 10a while the application rate 12 g a.i./10a slightly retared the growth of rice. The phytotoxicity decreased as the application time was delayed. The effect of application rate, leaching grade, transplanting depth, soil type and temperature on crop injury was little. Japonica variety (Dong-Jin) was more sensitive to bensulfuron methyl than indica X japonica variety (Sam-Kang). Bensulfuron methyl controlled effectively perennial weeds such as Sagittaria pygmaea Miq., Potamogeton diatinctus A. Benn., Cyperus serotinus Rottb., Sagittaria trifolia L., Eleocharis kuroguwai Ohwi. including most annual weeds except Echinochloa crus galli P. Beauv. The effect slightly decreased with lowering the temperature increasing the leaching grade. Application time and soil type employed did not affect the weeding effect.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.1-7
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• 2013

Studies were carried out to provide basic information for establishing the weed control in Chungbuk, Korea. The present surveys targeting 260 farmers in Chungbuk province were conducted for the cultivation system, weeds occurrence and usage of herbicides. To estimate the occurring area of herbicide resistant weeds, soil samples from 400 paddy fields were collected twice on August, 2011 and April, 2012. In the results of survey, the 99.6% of farmers used the rice planting machine and the 78% of the farmers disseminated herbicides twice to control weeds before and after planting rice. The most commonly used herbicide were as follows; soil-applied herbicide : butachlor 46.6%, mid-term herbicide : mefenacet + pyrazosulfuron-ethyl 10.7%, foliar herbicides : bentazone 62%. The dominant paddy field weeds included Echinochloa crusgalli (16.2%), Scirpus juncoides (12.2%), Monochoria vaginalis (11.9%) and Sagittaria trifolia (9.5%). Occurrence area of sulfonylurea herbicide resistant weeds was 13,659 ha in 26.8% of the paddy area. Monochoria vaginalis showed the highest with 4,605 ha (36.4%) followed Scirpus juncoides (30.7%), and Lindernia dubia (10.6%) at 2011. Monochoria vaginalis and Scirpus juncoides occurred were evenly distributed and the most problematic weed in Chungbuk, Korea.