• Title/Summary/Keyword: annual weeds

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Studies on the Herbicidal Properties of Bensulfuron methyl(DPX-F5384) -1. Variation of Phytotoxicity and Weeding Effect Caused by Herbicide Treatment in Mechanically Transplanted Paddy Field (제초제(除草劑) Bensulfuron methyl(DPX-F5384)의 작용특성(作用特性)에 관한 연구(硏究)- 제1보(第1報) 기계이앙답(機械移秧畓)에서의 약해(藥害) 및 약효(藥效) 변동요인(變動要因))

  • Ryang, H.S.;Jang, I.S.;Ma, S.Y.;Jeong, S.H.
    • Korean Journal of Weed Science
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    • v.6 no.2
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    • pp.134-145
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    • 1986
  • The experiment was crried out to evaluated the herbicidal properties of bensulfuron methyl [methyl 2-[[[[[(4, 6-dimethoxy pyrimidine-2yl) amino] carbonyl] amino] sulfonyl] methyl] benzoate]. No phytotoxicity was observed when bensulfuron methyl was applied at 3 and 6 g a.i./ 10a while the application rate 12 g a.i./10a slightly retared the growth of rice. The phytotoxicity decreased as the application time was delayed. The effect of application rate, leaching grade, transplanting depth, soil type and temperature on crop injury was little. Japonica variety (Dong-Jin) was more sensitive to bensulfuron methyl than indica X japonica variety (Sam-Kang). Bensulfuron methyl controlled effectively perennial weeds such as Sagittaria pygmaea Miq., Potamogeton diatinctus A. Benn., Cyperus serotinus Rottb., Sagittaria trifolia L., Eleocharis kuroguwai Ohwi. including most annual weeds except Echinochloa crus galli P. Beauv. The effect slightly decreased with lowering the temperature increasing the leaching grade. Application time and soil type employed did not affect the weeding effect.

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Weed Occurrence and Competitive Characteristic under Different Cultivation Types of Rice(Oyriza sativa L.) - 1. Distribution and Dominance of Weed and Rice (수도(水稻) 재배유형별(栽培類型別) 잡초발생양상(雜草發生樣相)과 경합특성(競合特性) - 제(第) 1 보(報). 잡초발생양상(雜草發生樣相)과 우점도(優占度) 변이(變異))

  • Im, I.B.;Guh, J.O.;Park, K.Y.
    • Korean Journal of Weed Science
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    • v.13 no.1
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    • pp.26-35
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    • 1993
  • Differences in weed occurrence was investigated among five types of rice (Oryza sativa L.) cultivation. The five types employed were three transplanting cultivations such as conventional hand transplanting, machine transplanting with 30-day-old seedling, and machine transplanting with 10-day-old seedling and two direct-seedings such as flood direct-seeded rice by pregerminated seed and dry direct-seeded rice by dry seed. Weed specie, occurred varied from 7 to 20, depending on the different cultivation types. Weeds were more diverse in transplanting with l0-day-old seedling than in other transplanting cultivations and in direct-seeding than in transplanting practice. Dominant weed species also varied with cultivation types. In transplanting cultivations Scirpus juncoides Roxb., Echinochloa crus-galli (L.) P. Beauv., and Eleocharis kuroguwai Ohwi were dominant, whereas occurrence of annual weeds such as Cyperus difformis L. and Monochoria vaginalis Presl. aside from the three weed species increased in direct-seeded cultivations.

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A Laboratory Test for Determining the Qulity of Imported pasture Plant and Forage Crop Seeds (수입목초 및 사료작물 종자의 품질에 관한 조사연구)

  • 조충섭;김동암
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.11 no.2
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    • pp.68-75
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    • 1991
  • A series of tests was carried out to determine the purity and germination of pasture plant and forage crop seeds imported in 1986 and 1987 at the grassland and forage laboratory, College of Agriculture, Seoul National University, Suweon. At the same time, the results obtained were compared with the National Livestook Cooperatives Federation(NLCF1's seed standards as a guide for determining seed quality. 1. The germination percentages of Potomac orchardgrass, Fawn tall fescue, Aquila Ky bluegrass and California ladino clover among grasses and legumes tested were lower than those of the N1,CF's standards, but the germination percentages of forage crops were higher than those of the NLCF's standards. 2. The purity of Potomac orchardgrass and Aquila Ky bluegrass were relatively lower than those of the NLCF's standards. 3. The percentages of other crop seeds in Potomac orchardgrass, Fawn tall fescue, Aquila Ky bluegrass and Cayuse oats were lower than those of the NLCF's standards. 4. Percentage of inert matter in the seeds was lower compared with the NLCF's standards except Akela ' forage rape. 5. The seeds of Potomac orchardgrass, NK 367 sorghum hybrid and sorghum x sudangrass hybrids such as NC+855, G83F and TE Haygrazer were contaminated with one or more weed seeds. Rumex spp. was by far the most common weed in the seeds imported. The other weeds occurred at a low level were Rumex acestosella, Senecio jacobaea, Cirsium arvense and Cuscicta spp. 6. There were many variations in 1,000 seed weight among different species. A thousand seed weight of Aquila Ky bluegrass was 0.263g, but that of Tetrone Italian ryegrass, Akela forage rape and Pioneer 3160 sorghum x sudangrass hybrid was 3.875, 3.476 and 242.4578, respectively. 7. According to the fluorescence test of ryegrass seed, Tetrone Italian ryegrass was known as a true annual type, but an unknown cultivar produced in Cheju was contaminated with 6% of perennial ryegrass seed.

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Controlled Release of Oxyfluorfen from the Variously Complexed Formulations IV. Effect of Water Level Depths on the Activity of Selected Formulations (수종(數種)의 결합제형(結合劑型)으로부터 Oxyfluorfen의 방출억제연구(放出抑制硏究) IV. 관개심(灌漑甚)에 따른 선발제형(選拔劑型) Oxyfluorfen의 약해(藥害).약효평가(藥效評價))

  • Guh, J.O.;Chon, S.U.;Kuk, Y.I.;Kwon, O.D.
    • Korean Journal of Weed Science
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    • v.11 no.3
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    • pp.159-166
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    • 1991
  • Seven oxyfluorfen formulations were tested for control of 8 weed species and rice injury under four different water depths with various ages of rice seedlings. Among formulations tested, rice injury was slight by formulations of Elvan, Coal Slag, Chitosan and Bentonite B under 0 cm or shallow water depths, and by those of Elvan and Coal Slag under deep water conditions. Weed control was high by Bentonite A and B, and Chitosan, and was low by Elvan. Coal Slag and Sand coated oxyfluorfen, if the target weeds of oxyfluorfen are annual species, further development of Elvan, coal slag, chitosan and Bentonite A would be controlled to increase control efficacy or to decrease rice injury.

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Collection, Conservation, and Utilization of Plant Genetic Resources -emphasis on weeds- (유용식물 유전자원의 수집 보존 및 이용에 관한 연구 -잡초를 대상으로-)

  • Kim, Kil Ung
    • Current Research on Agriculture and Life Sciences
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    • v.8
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    • pp.9-18
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    • 1990
  • Germinating ability of 54 weed species collected throughout Korea in 1987 and 1988 was determined in incubator at $25^{\circ}C$ for 15 days. The seeds of Echinochloa sp, collected from 70 different places throughout Korea, were classified by Yabuno's seed morphology method. Plant characters of two identified Echinochloa species, one having two subspecies were evaluated. SDS-PAGE(sodium dodecyl sulfate polyacrylamide gel electrophoresis) of seed protein assay was used to identify locally collected Echinochloa species classified by Yabuno's seed morphology method. 1. Out of 54 weed species collected, 31 species showed germination at 15 days after incubation, and 14 species showed over 50% and no germination was observed in 24 species, indicating that approximately 40 species had varied degree of germinating ability. 2. It was confirmed that two annual species of Echinochloa such as E. oryzicola and E. crus-galli occurred in Korea and one of which particularly E. crus-galli has two subspecies such as E. c. var. praticola and E. c. var. crus-galli. 3. E. oryzicola was distinguished from E. c. var crus-galli and E. c. var praticola by presence or absence of one major protein band in B zone. However, it was rather difficult to distinguish E. crus-galli species because they showed similar protein pattern.

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A study on the food habits of Korean native goats fed with roughage sources (조사료원에 따른 한국 재래산양의 채식습성에 관한 연구)

  • Gang, Byung-Ho;Lee, In-Duk;Lee, Soo-Kee;Lee, Hyung-Suk
    • Korean Journal of Agricultural Science
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    • v.38 no.3
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    • pp.445-452
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    • 2011
  • The object of this experiment was to investigate the food habits of Korean native goats fed with various roughage sources. The experimental trials were conducted at Unbong Animal Genetic Resources Station in 2008. The experimental roughages include five sources and 25 species in all; grasses and legumes: 5 species (mixed grasses, orchardgrass, tall fescue, alfalfa, white clover), native grasses and weeds: 5 species (mixed native grasses, Miscanthus sinensis Anderss, Arundinella hirta (Thunb.) Tanaka, Barnyard grass, short awn, forage crops and straw: 5 species (barley + hairy vetch, wheat + hairy vetch, rye silage, barley silage, baled rice straw), browse and fallen leaves: 5 species (Mixed browse, Oriental white oak, Quercus serrta Thunb., Oriental cherry fallen leaves, Japanese chestnut fallen leaves), and imported hay and straw: 5 species(timothy hay, tall fescue straw, annual ryegrass straw, klinegrass hay, alfalfa hay). Ten Korean native goats were selected which had nearly the same body weight (average $24{\pm}2.8$ kg). The chemical composition and dry matter digestibility of each roughage source and species were significantly different at the sampling area, plant species, growth stages and cutting period (p<0.05). Among all the 25 species of roughages, the favorite intake species order by Korean native goat was observed like this: Quercus aliena, Querancas serrta Thunb and Mixed browse, which was a lower intake compared to other domestic herbivores. The Korean native goats ate more roughages which had low fibrous contents, but high dry matter digestibility. The Korean native goats ate more roughages which had low fibrous contents, but high dry matter digestibility. On the other hand, compared to each roughage source, total intake amount by Korean native goats was showed as browse and fallen leaves (33.1%) among trials roughage sources. Based on these results, the food habit of Korean native goats seems to be closer to the browser.

Investigation of Weed Flora In Protected Semi - Irrigated Rice Seedbed (보온절충(保溫折衷) 못자리에 있어서 잡초군락(雜草群落) 조사연구(調査硏究))

  • Yim, J.H.;Chun, J.C.;Ryang, H.S.
    • Korean Journal of Weed Science
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    • v.5 no.1
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    • pp.14-18
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    • 1985
  • This experiment was conducted to characterize the weed flora in protected semi-irrigated rice seedbeds. There are 22 species in 16 genera and 12 families, consisting of 13 annual and 9 perennial weeds in protected semi-irrigated rice seedbed in Jeonbug province. The highest frequency was obtained with Echinochloa crusgalli(L.) Beauv., Cyperus difformis L., Eleocharis acicularis Rome et Schult, and Monochoria vaginalis Presl. Sites showing Simpson's index ranging from 0.1 to 0.5 reached 82% and 89% of all sites studied in 1983 and 1984, respectively. Dominant weed species were E. crus-galli and C. difformis in both years studied and the community dominance has changed from 0.67 in 1983 to 0.61 in 1984.

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Evaluation of Soil Erosion in Small Mountainous Watersheds Using SWAT Model: A Case Study of the Woldong Catchment, Anseong (SWAT을 이용한 최상류 소유역 토양침식 평가: 안성 월동저수지 유역을 대상으로)

  • Lim, Young Shin;Byun, Jongmin;Kim, Jin Kwan
    • Journal of The Geomorphological Association of Korea
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    • v.28 no.1
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    • pp.13-33
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    • 2021
  • Successful sediment management at the watershed scale requires an understanding of the erosion, transport and sedimentation processes at the specific site scale. However, studies on the sediment runoff characteristics in a small uppermost watershed, which serves as a sediment supply function, are very rare. Therefore, this study attempted to investigate the fluctuations in major sediment supply areas and sediment runoff in the uppermost mountain small watershed, and for this purpose, ArcSWAT (Soil and Water Assessment Tools with GIS interface) was applied to the Woldong reservoir catchment located in Gosam-myeon, Anseong-si, Gyeonggi-do. The model results were manually calibrated using the monitoring data of the Woldong reservoir sedimentation rate from 2005 to 2007. It was estimated that annual average of 34.4 tons/year of sediment was discharged from the Woldong reservoir basin. This estimate almost coincided with the monitoring data of the Woldong reservoir during the low flow period but tended to be somewhat underestimated during the high flow period. Although the SWAT model does not fully reflect the erosion process of gully and in-channel, this underestimation is probably due to the spatial connectivity of sediment transport and the storage and reactivation of the sediment being transported. Most of the forested hillslopes with a well-developed organic horizon were evaluated as having a low risk of erosion, while the places with the highest risk of erosion were predicted to be distributed in the logged area with some weeds or shrubs (classified as pasture) with relatively steeper slopes, and in the bare land. The results of this study are expected to be useful in developing strategies for sediment control and reservoir management.

Change of Weed Community in No-till Corn with Legume Cover Crops as Living Mulch (콩과 피복작물 리빙멀치에 따른 옥수수 무경운 재배지의 잡초군락 변화)

  • Choi, Bong-Su;Kim, Chung-Guk;Seong, Ki-Yeong;Song, Duk-Young;Jeon, Weon-Tai;Cho, Hyun-Suk;Jeong, Kwang-Ho;Kang, Ui-Gum
    • Korean Journal of Weed Science
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    • v.31 no.1
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    • pp.34-40
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    • 2011
  • Cover crop can be used to suppress weeds by competition for light and nutrient. Objective of this study was to evaluate the effectiveness of legume cover crops on change of weed community in no-till corn cultivation. Two legume cover crops, hairy vetch and crimson clover were grown in the field, and succeeding corn was sown on 4 May, 2010. The distribution of weed was surveyed at 15 April, 1 June, and 20 August. At 15 April, the weed biomass in hairy vetch field was higher than in crimson clover field. The dominant weeds were Capsella bursa-pastoris L. and Stellaria aquatica L. in hairy vetch and crimson clover fields, respectively. At vegetative stage of corn, occurred weeds in hairy vetch and crimson clover fields were four and six species, respectively, while the weed was occurred with nine species in conventional. Also the dry weight of weed was decreased by 82 and 75% in hairy vetch and crimson clover fields compared to conventional. On the other hand, after harvest of corn, occurred weed in hairy vetch, crimson clover and conventional was five, four and five species, respectively. Dry weight percentage of occurred weed in conventional was 23.5%, and the value was higher than 13.8 and 14.7% in hairy vetch and crimson clover fields, respectively. Stellaria aquatica L. as winter annual weed only occurred in cover crop field during corn growing season. It is these possibilities that low soil temperature and light interception by soil cover of legume cover crop.

A Demonstrative Study on the Intake Habits of Dairy Goats (Saanen) Fed with Roughages (유산양의 조사료 채식습성에 관한 실증적 연구)

  • Gang, Byung-Ho;Lee, In-Duk;Lee, Hyung-Suk
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.29 no.1
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    • pp.63-72
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    • 2009
  • The experiment was conducted from 2007 to 2008. The experimental roughages include five sources and 25 species in all; grasses and legumes: 5 species (mixed grasses, orchardgrass, tall fescue, alfalfa, white clover), native grasses and weeds: 5 species (mixed native grasses, Miscanthus sinensis Anderss, Arundinella hirta (Thunb.) Tanaka, barnyard grass, short awn, forage crops and straw: 5 species (barley 4- hairy vetch, wheat 4- hairy vetch, rye silage, barley silage, baled rice straw), browse and fallen leaves: 5 species (mixed browse, oriental white oak browse, Quercus serrta Thunb., browse oriental cherry fallen leaves, Japanese chestnut fallen leaves), and imported hay and straw: 5 species (timothy hay, tail fescue straw, annual ryegrass straw, klinegrass hay, alfalfa hay). Ten dairy goats (Saanen) were selected which had nearly the same body weight (25kg). The experiment was carried out on the dairy goats farm at Geumsan-Cun in Chungnam province. The chemical composition and dry matter digestibility of each roughage source and species were significantly different at the sampling area, plant species, growth stages and cutting period. Among all the 25 species of roughages, the favorite intake species order by dairy goats was observed like this: mixed grasses, white clover, alfalfa and the lower intake species order was baled rice straw and rye silages. The dairy goats ate more roughages which had low fibrous contents, but high dry matter digestibility. On the other hand, compared to each roughage source, the goat's favorite roughage were grasses and legumes (34.6%) among the trial species. Based on the result, it is reconfirmed that the food habit of dairy goats seems to be closer to that of graters.