• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.97-102
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• 2001

This study was carried out to survey the weed distributions in 6 areas(Suwon, Seonghwan, Seosan, Taekwanryeong, Namwon and Yeongam) and to investigate the ecological characteristics of exotic weeds from 1997 to 1999. Total 44 species in 15 families of exotic weds were observed in grassland and forage crop field. Among them 4 species in 1 family were monocotyledonous and 40 species in 14 families were dicotyledonous weeds. Most common species among exotic weeds examined in this study were Rumex acetosella, Rumex crispus. Chenopodium album, Abutilon theophrasti, Amaranthus retroflexus, Polygonum orientale etc. Inedible weeds with hairs, prickles, fetor or poison were Solanum carolinense Xanthium strumarium, Datura stramnium, Erechtites hieracifolia, Anthemis cotula, Phytolaca americana etc. The relative density of Phytolaca americana increased with decreament of soil pH and content of available phosphate, and that of Solanum carolinense increased with decreament of soil pH and increament of available phosphate. Most of exotic weed seeds germinated well under light condition with $25~30^{\circ}C$, and some of those were hard or dormant seed.

• Weed & Turfgrass Science
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• v.6 no.2
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• pp.109-116
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• 2017

This study was carried out two surveys in 2015 to monitor weed occurrence and determine the most troublesome weeds in peach orchards of Korea. The first survey identified 56 taxa belonging to 23 families including 27 annuals, 11 biennials, and 18 perennials. Based on importance values, Conyza canadensis (5.12%), Plantago asiatica (4.17%), and Trifolium repens (3.86%) were the dominant weeds in the first survey (from April to June). Seventeen exotic weeds were identified in the first survey, including Conyza canadensis, Trifolium repens, and Chenopodium ficifolium. The second survey (from September to October) identified 42 weeds belonging to 19 families including 23 annuals, 5 biennials, and 14 perennials. According to importance values, Digitaria ciliaris (8.00%) was the most dominant weed, followed by Echinochloa utilis (6.61%) and Rorippa palustris (6.48%). There were 12 exotic weeds, including Taraxacum officinale, Rumex crispus, and Trifolium repens. Additionally, according to Braun-Blanquet's scale showed that the dominance value was level 1 (41.98% and 46.43%, respectively) in two surveys. Currently, 40% of the total surveyed peach orchards applied herbicides for weed control. These results could provide basic data to assist orchardists in selecting the most suitable weed management methods; thereby, reducing labor inputs and effectively lowering costs while improving fruit yields in peach orchards of Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.103-108
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• 2001

This study was carried out to investigate the introduced route of exotic weeds and the effects of herbicide treatment. Herbicide trial was arranged as a completely randomized block design with treatment 1(\circled1 Dicamba $1\ell$/ha, \circled2 Mecoprop $5\ell$/ha, \circled3 Bentazone $3\ell$.ha, \circled4 Glyphosate $4\ell$/ha and \circled5 Pyrazosulfuron-ethyl 2kg/ha), and treatment 2(\circled1 Dicamba $2\ell$/ha, \circled2 Dicamba $4\ell$/ha, \circled3 Glyphosate $6\ell$/ha, \circled4 Glyphosate 4+Dicamba $1\ell$/ha and \circled5 Glyphosate 4+dicamba $2\ell$/ha) against 10 exotic weed species, and conducted in Suwon, Seosan and Yeongam from 1997 to 1999. Exotic weeds have been mostly introduced within imported cereals for concentrate feed or within seeds for forage production. Most of exotic weeds in forage crop field were controlled more than 95% by herbicide, but it was desirable that the control of exotic weeds was abreast of chemical and ecological method.

• Journal of Korea Multimedia Society
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• v.24 no.6
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• pp.745-752
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• 2021

In this paper, we propose a system that recognizes weed images using a classifier based on ResNeXt model. On the server of the proposed system, the ResNeXt model extracts the fine features of the weed images sent from the user and classifies it as one of the most similar weeds out of 21 species. And the classification result is delivered to the client and displayed on the smartphone screen through the application. The experimental results show that the proposed weed recognition system based on ResNeXt model is superior to existing methods and can be effectively applied in the real-world agriculture field.

• Weed & Turfgrass Science
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• v.3 no.4
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• pp.284-291
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• 2014

We surveyed the distribution of exotic weeds in the 350 upland crop fields of Gyeonggi-do. The exotic weeds were summarized as 78 taxa including 19 families, 52 genera, 74 species and 4 varieties. Among the total exotic weeds, the summer annuals were 48.7%, the winter annuals 28.2%, and the perennials 23.1%. Compositae was dominant family (32%), followed by Gramineae (8%), Polygonaceae (8%) and Malvaceae (7%). Dominant exotic weeds in northern Gyeonggi-do were Amaranthus lividus, Ambrosia trifida, Chenopodium album, Bidens frondosa and Erigeron Canadensis, and in southern Gyeonggi-do were Chenopodium album, Erigeron Canadensis, Erigeron annuus, Taraxacum officinale and Galinsoga ciliate. The most dominant exotic weeds in the Gyeonggi-do were Chenopodium album, followed by Amaranthus blitum, Erigeron canadensis. Canonical correspondence analysis for investigation of correlation between exotic weeds occurred in northern and southern Gyeonggi-do showed that the exotic weeds in northern Gyeonggi-do were more diverse then in southern Gyeonggi-do. This information could be useful for establishment of exotic weed control methods in Gyeonggi-do.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.236-242
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• 2015

We surveyed the distribution of exotic weeds in the 141 crop fields of Jeju island. The exotic weeds were summarized as 66 taxa including 18 families, 50 genera, 64 species and 2 varieties. In winter crop fields there were 45 species of exotic seeds in 18 families, in summer crop fields 50 species in 16 families, and in perennial crop fields 39 species in 17 families. Total exotic weeds were classified to 39.4% of summer annuals, 36.4% of winter annuals, 7.6% of summer and winter annuals, and 16.7% of perennials. The ratio of summer annuals were high in the summer crop fields. Compositae was dominant family, followed by Gramineae, Malvaceae and Solanaceae. Malvaceae did not appear in perennial crop fields. Dominant exotic weeds in winter crop fields were Chenopodium album, Amaranthus viridis, Senecio vulgaris and Coronopus didymus, in summer crop fields, Chenopodium album, Amaranthus viridis, Senecio vulgaris and Sonchus oleraceus and in perennial crop fields, Conyza sumatrensis, Gnaphalium calviceps and Senecio vulgaris. The dominant exotic weeds in the crop fields of Jeju island were Chenopodium album, followed by Amaranthus viridis, Senecio vulgaris, and Conyza sumatrensis. This information could be useful for establishment of exotic weed control methods in Jeju island.

• Journal of Ecology and Environment
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• v.38 no.3
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• pp.353-360
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• 2015

A survey of weed occurrence was conducted to identify problematic weed species in a horticultural crop field to get basic information for effective weed control. Surveys of weed species occurring in horticultural crop fields (garlic, onion, red pepper and Chinese cabbage) were conducted in Chungnam province of Korea from April to October in 2014. A total of 516 sites of the 17 regions were identified as having 114 weed species belonging to 32 families. The most dominant weed species in the horticultural crop fields were Chenopodium album var. centrorubrum (8.83%), followed by Digitaria ciliaris (5.71%), Conyza canadensis (5.46%) and Capsella bursa-pastoris (4.67%). Specifically, as a result of this study, the occurrence of 35 species of exotic weeds, such as Chenopodium album and Taraxacum officinale, were confirmed. Almost 68% of the investigation sites was determined under dominance value 1 (range of cover < 10; numerous individuals) by Braun-Branquet cover-abundance scale, indicating a proper weed control in horticultural crop field. As a result of scientific and technological advances, an improved cultivation method is changing the weed occurrence in agricultural land. Additional research needs to be undertaken for the development of weed control methods through such periodic monitoring of occurrence of weeds.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.59-67
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• 2010

The distribution of exotic weeds in 4 island area such as Baengnyeong-do, Heuksan-do, Chuja-do, and Geomun-do in Korea was investigated. Baengnyeong-do, Heuksan-do, Chuja-do, and Geomun-do have different weed flora, 41 species included 13 families, 32 species included 11 families, 23 species included 9 families and 30 species included 12 families were observed in the 4 islands, respectively. 18 families 70 species were occurred in 4 island. Most troublesome exotic weeds were Ambrosia artemisiifolia var. elatior, Solanum carolinense, Cuscuta pentagona. Occurrence frequency of Conyza canadensis, Erigeron annuus, Dactylis glomerata, Bromus catharticus and Lolium multiflorum were the highest in each island, respectively. Also, result of divided life cycle, annual weeds were 28 species occupied 40% in total, biennial weeds were 21 species (30%) and perennial weeds were 21 species (30%).

• Korean Journal of Agricultural Science
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• v.44 no.1
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• pp.40-49
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• 2017

Cultural practices for adzuki bean and the distribution of weed species in the south-west regions of Korea were surveyed to provide information on effective weed management. Approximately 27.5% of the farm households were growing adzuki bean in an area larger than 1 ha while the rest grew the crop in an area smaller than 1 ha. Of all adzuki bean growers, 17.1% seeded in early June, 8.6% in mid June, 34.3% in late June, 17.1% in early July, 20.0% in mid July, and 2.9% in late July. The average planting distance was $71.0{\times}29.5cm$. From the 40 surveys in adzuki bean fields, 35 weed species in 17 families were identified. According to the occurrence frequency, the dominant weed species were Digitaria sanguinalis, Acalypha australis, Cyperus amuricus, Echinochloa crus-galli, and Amaranthus nangostanus in decreasing order of dominance. However, based on dry weight, Chenopodium album (34.4%) was the most dominant followed by Acalypha australis (21.9%), Amaranthus nangostanus (19.1%), Digitaria sanguinalis (7.5%), and Portulaca oleracea (6.1%). The exotic weeds found in the field of adzuki were Ipomoea hederacea, Abutilon avicennae, and Celosia argentea. The plant heights of I. hederacea, A. avicennae, and C. argentea were 259 cm, 98 cm, and 76 cm, respectively, while the fresh weights were 850 g, 66 g, and 101 g, respectively. Integrated weed management systems utilizing mechanical, chemical, and biological control techniques need to be developed for effective weed management in adzuki bean production.

• Weed & Turfgrass Science
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• v.7 no.1
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• pp.1-14
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• 2018

We surveyed the distribution of exotic weeds in Korean paddy fields, uplands, orchards and pastures from 12,568 sites during 3 years, 2013, 2014 and 2015. As a result, 166 species in 28 families were identified and 7, 130, 126, and 80 species were surveyed from paddy fields, uplands, orchards, and pastures, respectively. Among the 166 species, 128 species were annual weed and 38 species were perennial weed. Especially, winter annual exotic weeds were 63 species (37.8%). 46, 16, and 104 exotic weeds were classified to their introduction period of $1^{st}$ (1876-1921), $2^{nd}$ (1922-1963), and $3^{rd}$ (1964-now) period, respectively. The exotic weeds introduced in $2^{nd}$ and $3^{rd}$ period, included 12 Invasive Alien Species. The weeds from $1^{st}$ period, however, could be grouped into native weeds as the 'naturalized weed' and managed the same as the native weeds. Especially, some exotic weeds such as common groundsel were widely distributed in Korean crop lands, and they will become more problematic in near future. Therefore, systemic research from the biology to management should be conducted and the results from the studies should be applied practically.