• Weed & Turfgrass Science
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• v.6 no.3
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• pp.165-178
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• 2017

This study was carried out to investigate the characteristics of weeds occurring in paeony field in June and July, 2015 in Uiseong, Cheongsong of Kyungbuk province, and Hwasun, Jangheung, Gangjin of Jeonnam province. In total paeony field, there were 35 families and 105 species, including 30 species of Asteraceae, nine species of Poaceae, eight species of Polygonaceae, and each five species of Fabaceae and Convolvulaceae, By life style, there were 49 species of annuals, 27 species of winter annuals and 24 species of perennials. In Kyeongbuk province, 30 families and 75 species were found including 20 species of Asteraceae, seven species of Poaceae, six species of Polygonaceae, each four species of Brassicaceae, Fabaceae and Convolvulaceae, three species of Euphorbiaceae. By life style, there were 35 species of annuals, 21 species of winter annuals and 19 species of perennials. In Jeonnam province, 34 families and 88 species were found including 23 species of Asteraceae, seven species of Poaceae, eight species of Polygonaceae, six species of Fabaceae and four species of Scrophulariaceae. By life style, there were 43 species of annuals, 15 species of winter annuals and 25 species of perennials. Therefore, there are various occurrences of annual, annual, and perennial weeds in peony fields, and weed control system should be set up accordingly.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.219-224
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• 2016

This study was conducted to investigate the ecology of weed occurrence and to establish an economical paddy field weed control system for direct-seeded rice on water. The main problem weed among annual and perennial weeds was Eleocharis kuroguwai. The control effect of E. kuroguwai was low by the application of azimsulfuron + carfentrazone-ethyl + pyriminobac-methyl at the early stages of rice in directly seeded paddy fields, but most annual weeds including Echinochloa crus-galli were controlled. Also, the additional application of pyrazosulfuron-ethyl + thiobencarb GR at 20 days after first treatment or of bentazone SL at 43 days after the first treatment effectively controlled E. kuroguwai. Tuber formation of E. kuroguwai was inhibited by the additional application of pyrazosulfuron-ethyl + thiobencarb by 84%, but the dormancy rate of old tubers of E. kuroguwai under the soil was higher than that of E. kuroguwai tubers following single application of azimsulfuron + carfentrazone-ethyl + pyriminobac-methyl at the early stages of rice. Tuber formation was inhibited by the additional application of bentazone by approximately 87%, and the old tuber dormancy rate was low in the bentazone treatment. High amounts of old dormant tubers of E. kuroguwai were found in the weedy plots.

• 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 CROP SCIENCE
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• v.62 no.1
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• pp.73-78
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• 2017

This study was conducted to elucidate the effects of mulching materials on root growth characteristics and weed occurrence of Platycodon grandiflorum transplants (3 years old) in organic farming. After transplanting, roots were mulched with one of three mulching materials (biodegradable film, sawdust, or rice husks) or a control (no mulching). The average root diameter of all mulching groups was 28.1 mm, which was 5.1 mm thicker than the no-mulching treatment. Roots with the biodegradable film treatment were the thickest at 30.9 mm. Root length was the shortest, 22.0 cm, with rice husk mulching. The number of rootlets was the highest with film mulching (36.0 rootlets/root) and the lowest with no mulching. For root fresh weight, which directly affects yield, the average of treated and untreated roots was 100 and 56 g/root, respectively. The highest fresh weight was in the biodegradable film plot (130 g/root). The mulching treatment groups showed a weed inhibition effect compared with the no-mulching treatment. The dominant weeds with the no-mulching treatment were Setaria viridis and Digitaria ciliaris, and that with the mulching treatment was Setaria viridis. Average annual weed occurrence across all treatments was 72%. Weed occurrence was the highest with the no-mulching treatment ($125weeds/m^2$), and there were no weeds with the biodegradable film treatment.

• Korean Journal of Medicinal Crop Science
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• v.6 no.1
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• pp.44-50
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• 1998

The experiment was carried out to investigate weed occurrence in peony field. The number of weeds was Compositate 9 species, Gramineae 4 species, Craciferae 3 species, Eugarviaceae, Polygonaceae and Scrophularilaceae 2 species, respectively. Weeds classified by life cycle were annual weed 19 species (57.6%), biennial weed 8 species (24.2%), and perennial weed 6 species (18.2%). Weed species and dominance rate by morphological characteristics were grass weed 4 species (12.1%), broad leaf weed 25 species (84.8%), and sedge weed 1 species (3.1 %) . Major dominant weeds were Capsella bursa-pastoris, Chemopodium album var. centrorubrum and Equisetum arvense in late April, and Digitaria sanguinalis, Erigeron canadensis and Echinochlor crus-galli in late June, and Digitaria sanguinalis, Erigeron canadensis and Echinochlor crus-galli in middle August.

• Weed & Turfgrass Science
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• v.3 no.2
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• pp.102-109
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• 2014

This study was conducted in order to utilize the basic data for weed control by surveying the occurrence of weed species and the degree of damages caused by those weeds occurred in cultivated Coix lacryma-jobi var. mayuen fields. Survey was carried out three times, from June to September in 2013. The weed flora was composed of a total of 98 weeds, 33 family, of which 58 species were annual, 21 species were biennial, and 19 were perennial plants. Thirty-one exotic species were included as well. Dominance was the highest with Digitaria ciliaris followed by Acalypha australis, Echinochloa crus-galli, Portulaca oleracea, Bidens frondosa etc. in order. In the PCA plot analysis, weeds occurred in C. lacryma-jobi var. mayuen fields were divided into three groups, Panicum dichotomitlorum community, Echinochloa crus-galli-Sigesbeckia pubescens community and Acalypha australis community. Yield of C. lacryma-jobi var. mayuen was reduced 60% in no weeding plots comparing to that in weed management plots.

• Weed & Turfgrass Science
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• v.3 no.2
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• pp.95-101
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• 2014

This study was conducted in order to utilize the basic data for weed control by surveying the occurrence of weed species and the degree of damages caused by those weeds occurred in cultivated Ligularia fischeri fields. Survey was carried out five times, on May, June, July, August and October in 2013. The weed flora was composed of a total of 104 weeds, 37 families, of which 55 species were annual, 25 species were biennial, and 24 were perennial plants. Twenty-six exotic species were included as well. Dominance was the highest with Chenopodium album followed by Stellaria aquatica, Echiochloa crus-galli, Conyza canadensis, and Artemisia princeps etc. in order. In the PCA plot analysis, weeds occurred in cultivated L. fischeri fields were divided into three groups, Persicaria thunbergii-Bidens frondosa community, Chenopodium album community and Capsella bursapastoris community. The degree of damages in cultivated L. fischeri fields was investigated by weighing roots of L. fischeri. We found that 56% decreased root weight in no weeding plots comparing to that in weed management plots. We infer from this result that decreased roots will affect to the growing of L. fischeri in following year.

• Korean Journal of Environmental Agriculture
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• v.20 no.2
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• pp.108-111
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• 2001

This study examined effects of aqueous extracts of rice bran on the inhibition of germination and early growth of annual weeds, barnyardgrass and eclipta. Germination of barnyardgrass treated with 5%(w/v)-sterilized and nonsterilized extracts of rice bran were inhibited by 27% and 63% at 7 days after treatment(DAT), respectively, compared to control. However, plant height and fresh shoot weight of barnyardgrass treated with aqueous extract of rice bran was reduced significantly at higher than 1% for both sterilized and nonsterilized extracts. Plant height and fresh shoot weight of barnyardgrass treated with 5% extract of rice bran were inhibited by 66 to 68% and 75 to 78% at 7 DAT, irrespective of sterilization. The germination of eclipta treated with sterilized and nonsterilized extracts of rice bran were significantly inhibited at concentrations of more than 0.5% and completely at 4% and 5%. Plant height and fresh shoot weight of eclipta affected by the rice bran extracts showed trends similar to the germination rate. The sterilization of rice bran extract resulted in higher inhibition of germination and early growth of eclipta. Rice bran extract was more inhibitory to the germination and growth of eclipta than barnyardgrass. These results suggest that aqueous extracts of rice bran may have inhibitory potential to germination and early growth of weeds.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.176-187
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• 2015

The weed flora in the Codonopsis lanceolata upland fields were surveyed in Hoengseong and Jeju in May, August, and October 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 occurred in C. lanceolata upland fields in Korea. Altogether 207 weed species of 47 families were identified, of which 87 were annual, 47 species were biennial and 73 were perennial. Based on the morphological characteristic of the leaves, 182 species were broad leaves, 18 species were grasses, and 7 species were sedges. The dominance was highest in the Artemisia princeps followed by Digitaria ciliaris, Commelina communis, Persicaria longiseta and Echinochloa crus-galli etc. Fifty-nine species were exotic weeds with 29% of a total presence, of which Erigeron annuus was highest, followed by Crassocephalum crepidioides, Bidens frondosa, Hypochaeris radicata etc. In the PCA plot, weeds presented in the C. lanceolata upland fields of Hoengseong were divided into three groups, E. annuus, Sigesbeckia pubescence and C. communis communities and those of Jeju were divided into four groups, C. crepidioides-Cyperus iria, Spergula arvensis, Poa annua and Youngia japonica communities.

• 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.