• 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.

• Korean Journal of Weed Science
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• v.17 no.3
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• pp.262-268
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• 1997

The experiment was carried out to obtain the basic information of weed control in lowland rice field in Gyeongbug province. The results were as follows : In weed distribution on life cycle, annual weed was occupied by 56.5% and perennials were 43.5%, respectively. In morphological distribution of weeds, grass weed was 25.2%, sedges was 12.3% and broad leaf weeds was 62.5%. In particular, weed occurrence of grass weed was much more increased than that of 1971 and 1981 year. Dominant weed species was Echinochloa crusgralli, Sagittaria trifolia, Eleocharis kuroguwai and Monochoria vaginalis in plain land, mid alpine area, and cold salty wind area. Dominant weeds was approximately similar occurrence in normal soil and poorly drained soil Gelds, but sandy soil field was not. Echinochloa crusgalli was dominant in hand transplanting and direct seeding on dry paddy field. Meanwhile, in machine transplanting, Sagittaria trifolia and Ludwigia prostrate were dominant, and occurrence of Echinochloa crusgalli was increased to delaying transplanting. As a result, major dominant weed was Echinochloa crusgalli, Sagittaria trifolia, Ludwigia prostrate, Eleocharis kuroguwai, and Monochoria vaginalis in terms of predominance.

• Korean Journal of Weed Science
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• v.32 no.1
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• pp.10-16
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• 2012

This study was carried out to investigate the agronomic traits, comparison of weed characteristics and possibility of gene flow in 'vitamin A enforced GM rice' and the donor plant, 'Nagdong'. The GM rice was not significantly different agronomic traits compared to the donor plant, Nagdong. Weed population changes were investigated in the cultivation of the GM rice and the donor plant, Nagdong. Dominant weed species and their dry matter did not show the difference between GM rice and the donor plant, Nagdong in macro-GM crop field. Dominant weed species with the GM rice and the donor plant, Nagdong were Monochoria vaginalis, followed by Eleocharis kuroguwai, Echinochloa crus-galli and Lindernia procumbens. The detection of gene from the GM rice was done using PCR, gene flow can't be detected by weed species. Results of this study on the agronomic traits, weed characteristics and possibility of gene flow has elucidated that GM rice might not be different from the donor plant, Nagdong.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.317-323
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• 1988

This survey was conducted to know characterization of weed occurrence under protected culture conditions at Yousong in 1985. Chenopodium album, Polygonum hydropiper, Portulaca oleracea and Digitaria sanguinalis were dominated in outdoor, whereas Capsella bursa-pastoris, C. album, D. sanguinalis and P. oleracea were dominant in polyethylene house. More weeds emerged in mulching plots and dry weight of weeds was greater in non-mulching plots. Summer broadleaf weeds and summer grasses were abundant in outdoor, whereas non-mulching plots in polyethylene house was dominated by winter broadleaf weeds, and mulching plots in polyethylene house were dominated by winter grasses and winter broadleaf weeds in early stage and summer grasses and summer broadleaf weeds in late stage. Simpson index was high in polyethylene house and Shannon's diversity index, maximum diversity for the Shannon diversity index were lower than eveness using the Shannon diversity index and this trend was more remarkable in mulching and mulching in tunnel than in non-mulching under polyethylene house condition. Shannon diversity index, maximum diversity for the Shannon diversity index were high in mulching or tunnel, and Simpson index was high in non-mulching in outdoor condition. Interspecific competition was more severe than intraspecific competition in both conditions.

• Korean Journal of Weed Science
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• v.13 no.2
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• pp.159-163
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• 1993

This research was conducted at the Crop Experiment Station to determine the changes of weed flora under direct seeded rice cultivation in dry paddy field from 1989 to 1992 and to establish an effective weed control strategy in direct seeded rice cultivation. With the continuous rice growing under direct seeded rice cultivation in dry paddy field, there were more occurrence in grasses and annual weeds while broadleaf and perennial weeds were diminished. The predominant weeds were aquatic weeds such as Eleocharis kuroguwai, Echinochloa crusgalli, and Monochoria vaginalis in machine transplanted rice paddy field while there were predominant of semi aquatic weed species such as E. crusgalli, Digitaria sanguinalis, Bidens tripartita, Aeschynomene indica, and Arthraxon hispidus in continuous direct seeded rice cultivation in dry paddy condition. Based on the vegetative analysis of weeds in terms of simpson index and community dominance, there was more distribution of weed species in direct seeded rice cultivation on dry paddy condition while only distributed with 1-2 weed species in machine transplanted rice paddy field. In similarity coefficient, there was a gradual increase up to 67% of weeds with the continuous direct seeded rice cultivation in dry paddy condition for 4 years starting from 41% of similarity coefficient.

• Korean Journal of Weed Science
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• v.18 no.4
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• pp.364-370
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• 1998

A weed population has been mainly analyzed through vegetative analysis method in ecology. However, this method is difficult to understand a detailed feature of weed dominance in terms of region and a particular weed species. Since GIS(Geographic Information System) tool has been introduced, this constraint was able to be solved. GIS analysis for the nationwide weed survey data in 1981 revealed that most predominant weed was Monochoria vaginalis and this species predominated mostly in a western part of Chungnam, a part of Kyunggi, a northern and southern part of Kyungbuk province of Korea. Eleocharis kuroguwai which was the most predominant weed species in 1992 was occurred at southern part of Kyunggi, central and western parts of Chungnam, and southern western part of Chumnam at the GIS analysis. GIS analysis was proven to give much more detailed information than vegetative analysis of weed population and this means that a data analysis by GIS would be used for operating a high effective control strategy against target weed species and site.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.12 no.2 s.101
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• pp.47-51
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• 1991

비농경지는 농산물과 임산물을 생산하는 농경지,임야등을 제외한 모든 공지를 의미하지만 잡초방제를 대상으로 보면, 택지, 공업용지와 도로, 고속도로, 철도, 학교 운동장, 공원 등이 포함되는 공공용지로 구분할 수 있다. 농경지는 국가경제가 발전될수록 계속 잠식되어 택지, 공장부지 및 공공용지로 이용됨에 따라 비농경지 면적은 점차 확대되고 있으며 따라서 비농경지에 발생된 잡초방제의 필요성은 더욱 증대되리라 예상된다. 그러나 아직 우리나라에서는 체계적으로 비농경지 잡초의 분포, 방제법 등에 관한 연구가 거의 이루어지지 않고 있으며 잡초방제의 중요성과 관심도 매우 적은 실정이다. 따라서 비농경지에서 발생되는 잡초의 종류 및 피해양상, 잡초방제의 특성과 제초제를 이용한 잡초방제법을 정리하여 보기로 한다.

• Korean Journal of Weed Science
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• v.18 no.1
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• pp.12-19
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• 1998

The pattern of rice cultivation in Korea is changing from hand transplanting and machine transplanting into direct-seeding for low input and cost-down practices. However, there are still some obstacles to establish the direct-seeding cultural practices because of poor seedling stand, lodging, and weed infestation. In particular, there were much more and wide weed occurrence in direct-seeding rice as compared with the transplanted rice. Weed occurrence in terms of dry weight of weeds was highest in dry direct-seeded rice followed by sowing an puddled soil, sowing on submerged soil in order as compared with transplanting with infant rice seedling. Echinochloa crux-galli was a common dominant weed with 35~44% distribution in any direct-seeding methods. The dominant weed species were E. crux-galli, Cyperus difformis, C. serotinus, and Ludwigia prostrata in dry-seeded rice. The dominant weed species in water-seeded rice were E. crus-galli, Eleocharis kuroguwai, Scirpus juncoides, and Monochoria vaginalis. Yield loss of rice due to weeds at weedy condition was 96% in dry direct-seeded rice. In water-seeded rice, yield loss was 61%, whereas yield loss was 40% in machine transplanting with infant rice seedling.

• Weed & Turfgrass Science
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• v.4 no.1
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• pp.1-9
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• 2015

Many irrigated and drainage canals, reservoirs, lakes, and rivers are choked by the explosive growth of aquatic weeds, resulting in enormous direct loss in Korea. Distribution of aquatic weeds and exotic invasive plant species in irrigation and drainage waterways, and riparian wetlands was reviewed to provide basic information for management of aquatic weeds and invasive plant species in wetlands. Dominant emergent weeds in canals, reservoirs and lakes were Phragmites communis, Leersia japonica, Zizania latifolia, Conyza canadensis, C. annuus, Rumex crispus, Panicum dichotomiflorum, Bidens frondosa, and Oenothera odorata. Dominant emergent weeds in wetlands of rivers include Digitaria sanguinalis, P. communis, R. crispus, Artemisia princeps, Humulus japonicus, Echinochloa crusgalli, B. frondosa, and Persicaria thunbergii. In irrigation and drainage canals and lakes, dominant submersed weeds were Hydrilla verticillata, Najas minor, Potamogeton malaianus, P. crispus, Ceratophyllum demersum, Myriophyllum verticillatum, Salvinia natans, and Trapa natans. Dominant exotic weeds in wetlands include Trifolium repens, O. odorata, C. annuus, B. frondosa, Avena fatua, Ambrosia artemisiifolia, X. strumarium, and P. dichotomiflorum. Approaches to aquatic weed control were mechanical, chemical and biological control techniques. Periodic monitoring of aquatic weeds and exotic weeds, and their integrated management studies are needed in waterways and riparian wetlands in Korea.

• Korean Journal of Organic Agriculture
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• v.17 no.4
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• pp.501-517
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• 2009

This research was carried out to study the effect of mulching materials and weed control methods on weed occurrence and growth of kale on upland and paddy soil of field culture at spring and autumn season. Paddy soil temperature of mulching treatments was high by $0.9{\sim}2.0^{\circ}C$ in comparison of non-mulching at autumn season. The control value of weed was over 91% at mulch paper and time required for weed control was reduced by 70% at mulch paper + machine weeding in comparison of non-mulching + hand weeding. The yield of kale was similar to that of conventional culture. Paddy soil temperature of mulch paper was higher on April, but lower on May and June than non-mulching at spring season. Dominant weed was Chenopodium album var. centrorubrum Makino, The control value of weed was over 91% at mulch paper, time required for weed control was reduced by 75% at mulch paper + machine weeding in comparison of non-mulching + hand weeding and the yield of kale increased by 34% than conventional culture. Dominant weed was Alopecurus aequalis var. amurensis Ohwi. on paddy soil at autumn season. The control value of weed was 43% at mulch paper. Time required for weed control was reduced by 80% at mulch paper + machine weeding in comparison of non-mulching + hand weeding. The yield of kale increased by 26% compared with than of conventional culture.