• Korean Journal of Weed Science
• /
• 제8권1호
• /
• pp.1-8
• /
• 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.

• FLOWER RESEARCH JOURNAL
• /
• 제18권2호
• /
• pp.98-109
• /
• 2010

78 Korean native plants, which have not been used in general, were selected to be used as outdoor pot plants for three seasons, from spring to autumn. Plants, which were explored in about 30 places of Korea from 2007 to 2009, were transplanted to or sown in white plastic general pots ($27.5cm({\Phi}){\times}27.5cm(H)$) and hanging pots($28cm({\Phi}){\times}13cm(H)$) and grown in the garden of 36''56' latitude(N) and 127''09' longitude(E). 38 species(13 families and 29 genus) were suitable for outdoor general pots, and 46 species(28 families and 43 genus) for outdoor hanging pots. Among 38 plants for outdoor general pots, the principal species, which were easy to grow and have not been used in general, were 16 species, Metaplexis japonica in Asclepiadaceae, Phyteuma japonicum in Campanulaceae, Artemisia capillaris, Artemisia princeps, and Artemisia selengensis in Compositae, Carex humilis in Cyperaceae, Pennisetum alopecuroides, and Setaria viridis in Gramineae, Agastache rugosa, Glechoma hederacea, Elsholtzia splendens, Isodon inflexus, and Mosla punctulata in Labiatae, Vicia villosa in Leguminosae, Piper kadzura in Piperaceae, and Rosa multiflora var. multiflora in Rosaceae. Among 46 plants for outdoor hanging pots, the principal species, which were easy to grow and have not been used in general, were 17 species, Metaplexis japonica in Asclepiadaceae, Ixeris stonlonifera in Compositae, Calystegia japonica and Quamoclit angulata in Convolvulaceae, Dioscorea batatas in Dioscoreaceae, Glechoma hederacea and Thymus quinquecostatus in Labiatae, Trifolium lupinaster for. alpinus and Vicia villosa in Leguminosae, Menispermum dauricum in Menispermaceae, Piper kadzura in Piperaceae, Clematis mandshurica for. lancifolia in Ranunculoideae, Rosa multiflora var. multiflora and Potentilla fragarioides var. major in Rosaceae, Paederia scandens and Rubia akane in Rubiaceae, and Parthenocissus tricuspidata in Vitaceae.

• Korean Journal of Plant Resources
• /
• 제13권3호
• /
• pp.243-248
• /
• 2000

This study was conducted to evaluate the effects of weed control and lodging reduction in the cultivation of buckwheat. The effect of weed control was significant. In the herbicide plot, nevertheless, grain yield and plant height were more decreased than habitual and vinyl mulching plots. Therefore, the application of herbicide was considered unnecessary in buckwheat cultivation having short growth period. In the habitual plot, dominant weed species are Digitaria sanguinalis, Erigeron annuus, E. canadensis, Setaria viridis, and Stellaria alsine var. undulata. On the effect of plant dwarf agent, C.C.C. and TIBA, plant height became shorter than habitual plot but the grain yield decreased. The latter tip pinching time, the less in grain yield which indicate tip pinching is ineffective in grain yield and lodging reduction. Among the wild species and cultivars of Fagopyrum, F. urophyllum was differentiated into xylem and phloem tissues indicating woody plant. Stem hardness of this species was the hardest as 625,110,000 dyne/cm$^2$which is at least 3.5 times harder than F. esculentum cv. Suwon #12. Therefore, it needs that the woody habitat gene of F. urophyllum is transfered into other cultivars in buckwheat breeding strategy.

• Korean Journal of Environmental Agriculture
• /
• 제15권1호
• /
• pp.46-69
• /
• 1996

The studies were conducted to obtain the basic information of the effects of pollutants on plant species and to select the plant species showing specific responses to the pollutants. For these purposes, paraquat, ammonium, and cadmium as a source of oxidative stress, nitrogen toxicity, and heavy metal toxicity respectively were treated to the plant species. Among the tested plants, Lamiaceae, Brassicaceae, and Caryophyllaceae were tolerant to paraquat, whereas Poaceae and Asteraceae were sensitive. Especially Mosla dianthera of Lamiaceae, Hemistepta lyrata and Aster pilosus of Asteraceae, and Paspalum thunbergii of Poaceae showed higher tolerance than others. Paraquat resistance was related with life style, overwintering capacity, so perennial and biennial species showed higher tolerance than annual species. In response to ammonium, Poaceae showed higher resistance while Fabaceae and Caryophyllaceae showed sensitiveness. Weed species having tolerance to ammonium were Echinochloa crus-galli var. praticola, Panicum dichotomiflorum, Setaria glauca, Chenopodium album, and Solanum nigrum, while Mosla dianthera, Arenaria serpyllifolia and Perilla frutescens var. japonica showed sensitiveness. In the response of plant species to cadmium, Digitaria sanguinalis, Amaranthus lividus showed higher resistance, whereas Galinsoga parviflora, Plantago asiatica, Ambrosia trifida, and Paspalum thunbergii showed sensitiveness. The injured degree on germination stage by pollutants did not related with injured degree on matured stage. During germination, the root elongation was more sensitive than shoot elongation by pollutants, paraquat, ammonium, and cadmium.

• Korean Journal of Weed Science
• /
• 제7권3호
• /
• pp.265-279
• /
• 1987

About 140 weed species belonging to 42 families occurring in summer were observed in Ulreung island. The Compositae was the most wildely occurring family covering 27 weed species, followed by 21 species in Graminae, 9 in Polygonaceae, 7 in Leguminosae, and 7 in Labiatae etc. In terms of the lands classified, about 60 species in 26 families were observed in the cultivated and the medical crops grown areas, respectively, and 116 species in 40 families occurred in the non-cultivated land like the vicinity of the cultivated area and 94 species in 34 families in the valley. No. of species and families were much greater in the non-cutivated land than those of the cultivated one. The most dominant weed species in both the cultivated and its vicinity in Ulreung island were Digitaria sanguinalis, followed by Portulaca oleracea, Polygonum hydropiper, Equisetum arvensis, Artemisia princeps, Commetina communis, Setaria viridis in order. Community analysis was done by the method of Toyohara in two cultivated lands such as the general crop land and the medical herb crop grown land, and two non-cultivated areas such as the vicinity of the cultivated land and valley. The cultivated land consisted of the communites of P. hydropiper and Cyperus amuricus, including Bidens tripartita in P. hydropiper community. The medical crop grown land composed of three major communities like P. hydropiper, Amaranthus mangostanus and Sonchus asper in which A. mangostanus and S. media were presented in the ecoton, indicating community being transiting. In the non-cultivated areas like the vicinity of crop land, the communities of Erigeron annuus, P. oleracea, and Oxalis corniculata were dominant, and Dystaenia takeshimana was included in the community of E. annuus and Stellan'a aquatica in P. oleracea community. In the valley, Ranunculus quelpaertensis community was existed in between the communities of Sonchus asper and Plantago asiatica.

• Korean Journal of Weed Science
• /
• 제2권2호
• /
• pp.160-168
• /
• 1982

Nine combined dosal levels of Paraquat and Oxyfluorfen were compared on pear orchard to control Digitaria adscendens Henr, and others, namely Commelina communis L., Erigeron annuus L., Echinochloa crusgalli P. Beauv var. oryzicola Ohwi, etc.. By treating as an early-postemergence, the mixtures showed higher control effects than 85% of the whole weeds, but the control effects in the mono-treatments of respective herbicide were only 20% or so. On the other hand, as a late-postemergence, the control rates were fluctuated from 31% to 94%. However, there was no significant difference in Spearman's rank correlation coefficients between both efficacies. Thus indicate that the action style of synergistic effect was not influenced by the application time, and the levels of mixtured dosages should be adjusted by the application times and interfering conditions.

• Korean Journal of Weed Science
• /
• 제12권4호
• /
• pp.317-334
• /
• 1992

Weed flora and floristic composition were reviewed in lowland rice field and upland crop area. For lowland rice field weed flora was not much changed since 1971. About 29 weed species belonged to 18 families were occurred. However, floristic composition of dominant weed species has greatly changed mainly due to introduction of herbicides. The predominant weed species in 1971 when herbicide was not used were Rotala indica, Eleocharis acicularis, Monochoria vaginalis, Echinochloa crus-galli, while these for in 1991 were Eleocharis kuroguwai, Sagittaria pygmaea, S. trifolia, Echinochloa crus-galli and M, vaginalis, respectively. In 1981 weed survey, E. crus-galli was no longer troblesome weed. However, this species became important again thereafter by introduction of herbicide mixtures with pyrazolate, bensulfuron-methyl or pyrazosulfuronethyl. For upland crop area, 216 weed species belonged to 46 families were recorded. One hundred and sixtyfive of these were grown in winter crop area while 189 weed species occurred in summer crop area, respectively. Among these, 138 weed species were grown in both crop seasons. In general, summer crops had less number of weed species compared to winter crops. Even though the dominant weed species varied by crop the most common weeds were Chenopodium album, Alopecunrs aqualis, Stellaria alsine and S, media for winter crops and Digitaria sanguinalis, Portulaca oleracea, Chenopodium album and Acalypha australis for summer crops, respectively.

• Journal of Wetlands Research
• /
• 제7권4호
• /
• pp.67-80
• /
• 2005

Vegetation structure of the vascular plants was investigated from April 2003 to August 2003 in Hwangjeong wetland around Geumho River, Yeongcheon-si, Gyeongsangbuk-do, Korea. Actual vegetation of Hwangjeong wetland largely can be classified by the floristic composition and the physiognomy into 12 communities; Ambrosia artemisiifolia var. elatior, Humulus japonicus, Miscanthus sacchariflorus, Phragmites japonica, Zizania latifolia-Miscanthus sacchariflorus, Zizania latifolia-Nymphoides peltata, Miscanthus sacchariflorus-Phragmites japonica, Phragmites communis-Phragmites japonica, Phragmites japonica-Salix gracilistyla, Salix koreensis-Salix glandulosa, Salix nipponica-Salix koreensis, and Phragmites japonica-Zizania latifolia. Among them, the distribution area of the Phragmites japonica community was the largest as 49.46 ha(11.03%). The dominant vegetation type was Phragmites japonica community and Ambrosia artemisiifolia var. elatior community based on the phytosociological method, and Phragmites japonica community was classified into two subcommunities; Nymphoides peltata subcommunity and Salix glandulosa subcommunity. Differential species of Phragmites japonica community were Phragmites japonica, Miscanthus sacchariflorus, Persicaria thunbergii, Oenanthe javanica, Leersia oryzoides var. japonica, and Rorippa indica; differential species of Ambrosia artemisiifolia var. elatior community were Ambrosia artemisiifolia var. elatior, Setaria glauca, Commelina communis, Cyperus orthostachyus, Digitaria sanguinalis, Xanthium strumarium, Erigeron annuus, Erigeron canadensis, Kummerowia striata, Trifolium repens, and Medicago sativa; differential species of Nymphoides peltata subcommunity were Nymphoides peltata, Zizania latifolia, Scirpus tabernaemontani, and Eleocharis mamillata var. cyclocarpa; differential species of Salix glandulosa subcommunity were Salix glandulosa, Salix koreensis, and Salix gracilistyla. It was expected that Hwangjeong wetland is worthy of conservation contributed purifying water pollution, giving habitats of many lifes, and providing beautiful scenes of Geumho River.

• Applied Biological Chemistry
• /
• 제18권1호
• /
• pp.30-41
• /
• 1975

A substituted diphenyl ether herbicide(MC-4379) was studied on the decomposition by some environmental factors; sunlight, microorganisms, and the crude enzyme in rice plant extract. All the decomposition products were confirmed by means of TLC, GLC, and IR. The parent compound and the decomposition products were put to the test for the effect on the growth of some plants. The results obtained are summarized as follows: 1. Photolysis Amino-MC-4379, 2,4-dichloro-3'-carboxyl-4'-nitrodiphenyl ether, Nitrofen, 2,4-dichloro-3'-carboxyl-4'-amino-diphenyl ether, amino-Nitrofen, 3-carboxymethyl-4-nitrophenol, p-nitrophenol, p-aminophenol, etc. were confirmed as photoproducts, in addition to a relatively small amount of an unknown compound. It was confirmed that the solution-phase photolysis of MC-4379 was accelerated much more by the aid of a photosensitizer benzophenone. 2. Degradation by the crude extract of germinating rice seeds Nitrofen was confirmed as a major degradation product, in addition to a relatively small amount of and unknown compound. Most of the parent compound remained unchanged. 3. Degradation by microorganisms Nitrofen and amino-MC-4379 were confirmed as the major products. in addition to a small amount of an unknown compound. 4. The germinating rice seeds and soybean were grown in the 1,000 ppm emulsions of some chemicals, respectively. The effect on rice plant growth was in the inhibitory order of p-nitrophenol > C-6989> Nitrofen > amino-Nitrofen > MC-4379. The effect on soybean was in the order of Nitrofen > amino-Nitrofen > MC-4379. Two weeds, Amantus blitum and Setaria viridis were grown in the 500 ppm emulsions containing the compounds, respectively. After incubation for 3 days, it was observed that all the shoots had been dead.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• 제56권2호
• /
• pp.134-139
• /
• 2011

This study was conducted to evaluate the weed suppressing effects of two winter cover crops, hairy vetch and rye in foxtail millet and sorghum fields in 2010. Crop growth and development and weed occurrences in the fields were examined to know the efficiency of proposed cropping system. In hairy vetch treated plots, heading of minor cereals occurred early. The heading date was earlier by 1 day and 2 days in sorghum and foxtail millet, respectively. However, rye treatment delayed heading by 12 days and 8 days in sorghum and foxtail millet, respectively. Besides he effect of cover crop on ear emergence of crops, the Besides changed growth-related characteristics. Plant height, chlorophyll content and chlorophyll fluorescence of sorghum ere increased in hairy vetch treatment by 46.4% 88.7% and 7.9%, respectively. In foxtail millet, the characteristics ere also increased by 45.6%, 50.9% and 37.8%, respectively, s compared to control. Yields of sorghum and foxtail millet were increased by 105.1% and 135% as compared o control by hairy vetch treatment, respectively. However, he yields of cereal crops were decreased by rye cover crop treatment, the yields of sorghum and foxtail millet were decreased by 25.8% and 119.1%, respectively. Rye cover crop treatment inhibited crop growth suggesting nitrogen starvation in rye treated plots. In rye treatment, plant height, chlorophyll contents and chlorophyll fluorescence of sorghum ere slightly decreased by 7.1%, 10.8% and 10.8%, respectively, as compared to control whereas the inhibitory effects were greater in foxtail millet. Weed occurrences based n weed number in hairy vetch and rye plots were reduced n weed number in hairy vetch and rye plots were reduced y 27% and 20%, respectively. The smothering effect was weakened or disappeared after heading of crops. Weed number and dry weight in hairy vetch plot were increased by 159% and 55.2%, respectively, as compared to control. The results implied that weed suppressing of cover crops could be reduced drastically after heading of crops.