• Korean Journal of Weed Science
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• v.7 no.1
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• pp.3-11
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• 1987

The study was conducted to identify growth habit of Monochoria vaginalis gathered from three different locations (Suweon, Jeonju and Milyang). The plant height, number of leaves and dry weight of M. vaginalis gathered from three different locations were greatly affected by the seeding dates. The earlier the seeds of M. varginalis sown, the greater M. vaginalis grew, In general, the earlier seeding dates produced significantly longer plant height, number of leaves and dry weight than those of later seeding dates, showing no difference in the collection of weed seeds in different locality. The earlier seeding dates resulted in the earlier flowering, but the interval between dates of seeding and flowering decreased progressively as the seeding times were delayed. Seed production was not significant among three locations and but seeding date on June 15 produced th highest seed production as compared with other seeding times. No. of flowers and capsule per pot among yield components were two major factors affecting seed production.

• 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.8 no.1
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• pp.1-8
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• 1988

In order to get basic information for establishing weed control methods, weed distribution was surveyed at 15 days interval in garlic and red pepper fields at 8 locations in Chungnam Province. In garlic fields, 68 weed species(27 families) were distributed. Portulaca oleracea, Chenopodium album and Digitana sanguinalis were most dominant and Equisetum arvense, Alopecurus aequalis, and Setaria viridis dominant among them. Highest number of weeds emerged in May and dry weight or weeds was more heavy in June and summer broadleaf weeds were most abundant throughout garlic growing period. In red pepper fields, 38 weed species(17 families) were distributed, D. sanguinalis, Cyperus amuricus and P. oleracea were most dominant and Echinochloa crus-galli, Eleusine indica, D. violascens, and Centipeda minima also dominant among them. The highest number of weeds were emerged in June and summer, grasses and summer broadleaf weeds were more abundant in June and July. Seasonal Shannon's diversity index(H'), maximum diversity(Hmax') and eveness(J') for the Shannon diversity index, and Simpson index were high in both red pepper and garlic fields. Interspecific competition(probability for interspecific encounter) was more severe than intraspecific competiton.

• Korean Journal of Weed Science
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• v.5 no.1
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• pp.24-34
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• 1985

To estimate the fundamental situation of weed emergence and it's competition to paddy rice (critical competition period and threshold level) in the southern paddy area in Korea, two rice cultivars (Pungsanbyo and Tongjinbyo) under two cropping periods (Mono- and After-barley-cropping) were experimented. As a result, the dominant weed species (Monochoria vaginalis and Scirpus juncoides Roxb.) and the better emerging conditions (rather at the monocropping and cv. Punsanbyo) were identified. Also, the main components of yield decrease (25-55% of the weed-free check) of both cultivars as affected by weed competition were the number of spikelets, panicle and ripening rate in monocropping, and the ripening rate and grain weight in after-barley-cropping, respectively. Under the situation of combinated dominance with Monochoria v. and Scirpus j. among others, the duration of critical competition periods was enlarged.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.230-235
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• 2016

Miscanthus are perennial rhizomatous grasses and considered as an ideal cellulosic bioenergy crop. Recently, it was reported that Miscanthus was damaged by the larvae of rice stem borer, Chilo suppressalis Walker, one of the most destructive pests of rice in Korea since the 1960s. This study was thus conducted to evaluate the insecticidal effects against rice stem borer in the Miscanthus cultivation fields for two years. The experiment consisted of four chemical agent plots, one environment-friendly agent plot, and untreated plot. Untreated plot showed significantly high damage of 50%, while Buprofezin Tebufenozide and Carbosulfan Methoxyfenozide treatment plots showed low damage rate of 2% with low larvae density of 1 and $2.3larvae\;m^{-2}$, respectively. Damage rates of Tebufenozide, ChlorantraniliproleIndoxacarb, and environment-friendly agent(MatrineWood vinegar solution) were 15, 26, and 18%, respectively, which were lower than that of untreated plot but higher than those of Buprofezin Tebufenozide and Carbosulfan Methoxyfenozide. In conclusion, rice insecticides were effective against rice stem borer in Miscanthus field. In particular, the treatments with Buprofezin Tebufenozide and Carbosulfan Methoxyfenozide showed excellent control effects with control value of 93.3 and 95.2. However, further studies with different types of insecticides should be carried out for the selection of insecticides with more effective control of rice stem borer.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.521-547
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• 2018

To provide fundamental information to areas that lack data on the plant resources and the ecosystem, this study conducted a survey on the vascular plants in Mt. Jigisan in Hongseonggun. The vascular plants identified during the six-round field surveys were a total of 443 taxa: 96 families, 286 genera, 391 species, 7 subspecies, 40 varieties, 3 forms, and 2 hybrids. On floristic regional of Korea, Mt. Jigisan is deciduous broad-leaved and conifer-mixed forest which is south province of Korean peninsula. 4 taxa of Korean endemic plants such as Populus ${\times}$ tomentiglandulosa, Forsytsythia koreana, Forsytsythia ovate, and Iris rossii var. latifolia were collected. The vascular plants on the red list according to IUCN evaluation basis were found to be 6 taxa: Vulnerable (VU) species of Forsytsythia ovata, Least Conern (LC) species of Chionanthus retusus, Pseudoraphis ukishiba, and Cymbidium goeringii, and Not Evaluate (NE) species of Panax ginseng, and Fimbristylis verrucifera. The floristic regional indicator plants were found 27 taxa: 2 taxa of grade V, 3 taxa of grade IV, 6 taxa of grade III, 4 taxa of grade II, and 12 taxa of grade I. The specific distribution plants were found 27 taxa: 4 taxa of northern part of plants, 12 taxa of southern part of plants, 10 taxa of isolation distribution of plants, and 1 taxon of recently reported Viola betonicifolia var. albescens. The invasive alien plants were identified as 67 taxa. The naturalized index (NI) was 15.12%, and urbanization index (UI) was 20.9%, respectively.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.439-455
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• 2018

Hanon made in the largest maar crater in Korea, is the only paddy field ecosystem in Jeju Island that has been conducting rice farming, for the past 500 years. Flora surveys were conducted eight times, 2015-2018, to understand floristic characteristics and a restoration plan of the study area. As a result, vascular plants of Hanon paddy fields were listed 225 taxa that consist of 55 families, 151 genera, 194 species, 1 subspecies, 25 varieties, and 4 forms. The taxonomic group including the most species, was Gramineae (36 taxa). The next families were Compositae (29 taxa), Cyperaceae (20), Leguminosae (13), and Polygonaceae (11). Biological type of the Hanon was $Th-R_5-D_4-t$ type. The rare plants revealed 3 taxa; Ottelia alismoides(L.) Pers., Acorus calamus L., Pseudoraphis ukishiba Ohwi. Endemic plant revealed 1 taxon; Saururus chinensis(Lour.) Baill. Forty three taxa were naturalized plants composed of 15 families, 24 genera, 41 species, and 2 varieties. The urbanization index and naturalized index were 13.3% and 16.9%, respectively. The Hanon has high plant diversity, including endemic plant and rare plants, and is the only rice paddy in Jeju Island. So, the Hanon has sufficient values in ecological and socio-cultural aspects, so it should be maintained continuously in the future.

• Korean Journal of Weed Science
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• v.3 no.1
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• pp.23-28
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• 1983

To study ecological characteristics of Eleocharis kuroguwai occuring in Korea its propagules were collected from 6 locations from the northern part to the southern part of Korea (Chuncheon, Suweon, Iri, Jeonju, Gwangiu and Milyang) in 1981, cultured and replanted 3 times (May 20, June 5, June 20) in 1982. They flowered from August 5 to August 27 when they were planted on May 20, and from August 20 to August 27 when they were planted on Tune 20. Plant height, number of tillers and top fresh weight/$m^2$ were 50-90cm, 500-875, and 175-750g, respectively when they were planted on May 20, and 40-70cm, 250-625, 325-625g, respectively when they were planted on June 20. Number of tubers per plant were 0.98-1.98 when they were planted on May 20, and 1.81-2.87 when they were planted on June 20. Eleocharis kuroguwai from Chuncheon or Suweon was more open in plant type, shorter in plant height, narrower in diameter of pedicel and shorter in inflorescence than those from Iri, Jeonju or Gwangju. Each of the local collections may be regarded as different ecotype, based on the above differences in morphology and responses in growth and flowering to the planting dates. The results appear to imply that Eleocharis kuroguwai weeds occurring in various locations of Korea are different one another in competitive avility with rice crop.

• Korean Journal of Weed Science
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• v.17 no.2
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• pp.147-156
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• 1997

The survey of weed population in apple orchard was conducted to investigate basic information on weed flora and its ecology at 27 locations in 1996. The weed species observed include 7 species of grasses, 60 species of broadleaves and 2 species of sedges, and the ratio of annual weed vs perennial weed was 64 : 36. Major dominant weed species by frequence were Chenopodium album, Capsella bursa-pastoris, Digitaria sanguinalis, Rorippa islandica, Alopecurus aequalis and Erigeron canadensis. While, on the basis of dry weight, the most dominant weeds were C. album followed by E. canadensis, A. aequalis, R islandica and R indica. The dominant weed species in middle-north Kyeongbuk region were C. bursa-pastoris, C. album, R indica and R islandica, were E. canadensis, Persicaria hydropiper, A. aequalis and Arenaria serpylliforia in Chungbuk region and were A. aequalis, E. canadenris and R islandica in Honam region.

• Weed & Turfgrass Science
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• v.3 no.2
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• pp.86-94
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• 2014

Survey was carried out in paddy fields to investigate the dominance of weed species and weed occurrence on 200 fields of southern Gyeonggi region in Korea during the year 2013. We observed 3 species of grass, 5 species of sedge, and 11 species of broadleaf and other weeds. The most dominant weed species was Eleocharis kuroguwai, followed by Echinochloa crus-galli, Sagittaria trifolia, Monochoria vaginalis, Scirpus juncoides and Bidens tripartita. The dominance value of E. kuroguwai and B. tripartita decreased compared to the survey results performed in 2005 but that of M. vaginalis, S. juncoides, S. trifolia and E. crus-galli increased. Weed occurrence increased from 2.83 g in 2005 to 3.51 g in 2013 based on weed dry weight per $m^2$. Occurrence ratio of annual weeds to perennial weeds changed from 45.2% : 54.8% in 2005 to 45.8% : 54.2% in 2013. If we analyze dominance of weed species based on the rice transplanting timing, E. kuroguwai and E. crus-galli were the most dominant weed species at mid-May transplanting, and M. vaginalis and S. juncoides were the most dominant weed species at late- May transplanting, and M. vaginalis and E. kuroguwai were the most dominant weed species at early-June transplanting. Since paddy weeds resistant to sulfonylurea herbicides are expected to be continuously increased, the regular monitoring of their occurrence and efficient control methods should be considered in future.