• Title/Summary/Keyword: paddy weed

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Rice Yield Loss and Economic Threshold Levels by Densities of Scirpus planiculmis and Lindernia dubia in Wet-Seeded Rice Paddy Fields (벼 담수직파논에서 새섬매자기와 미국외풀 발생밀도에 따른 쌀 수량 감소와 경제적 방제수준)

  • Kwon, Oh-Do;An, Kyu-Nam;Lee, Yeen;Shin, Seo-Ho;Park, Heung-Gyu;Shin, Hae-Ryoung;Moon, Byeong-Cheol;Kuk, Yong-In
    • Korean Journal of Weed Science
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    • v.31 no.4
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    • pp.348-354
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    • 2011
  • This study was conducted to find the levels of reduction in rice yield and to determine economic threshold levels as affected by densities of Scirpus planiculmis and Lindernia dubia in wet seeding rice cultivation. In wet seeding rice cultivation, yield of rice in densities of S. planiculmis (192 per $m^2$) and L. dubia (384 per $m^2$) was reduced by 43 and 22%, respectively. Relationship between rice yield and densities of weeds were predicted with these equations of Y=531.3kg/(1+0.003931x), $r^2$=0.964 for S. planiculmis and Y=547.0kg/(1+0.000792x), $r^2$=0.922 for L. dubia. According to Cousens' method, economic threshold densities of S. planiculmis and L. dubia were calculated by 7.2 and 34.9 per $m^2$, respectively. This result indicated that yield of rice in wet seeding rice cultivation could be reduced by over economic threshold densities of S. planiculmis and L. dubia.

Classification According to Site of Action of Paddy Herbicides Registered in Korea (국내 수도용 제초제의 작용기작별 분류)

  • Park, Jae-Eup;Kim, Sang-Su;Kim, Young-Lim;Kim, Min-Ju;Ha, Heun-Young;Lee, In-Yong;Moon, Byung-Chul;Ihm, Yang-Bin
    • Weed & Turfgrass Science
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    • v.3 no.3
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    • pp.165-173
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    • 2014
  • This review study was conducted to recommend the effective use of herbicide mixtures in Korea. The herbicide ingredients by Herbicide Resistancce Action Committee (HRAC) was classified into 23 groupes according to the mode of action (acetyl CoA carboxylase inhibitors, acetolactate synthase, photosystem I and II inhibitors, protoporphyrinogen oxidase inhibitors, carotenoid biosynthesis inhibitors, enolpyruvyl shikimate-3-phosphate synthase inhibitors, glutamine synthetase inhibitors, dihydropteroate synthetase inhibitors, mitosis inhibitors, cellulose inhibitors, oxidative phosphorylation uncouplers, fatty acid and lipid biosynthesis inhibitors, synthetic auxins, auxin transport inhibitors and potential nucleic acid inhibitors or non-descript mode of action). The rice herbicide mixtures registered in Korea were classified based on the guideline of HRAC. Accordingly, such a classification system for resistance management can help to avoid continuous use of the herbicide having the same mode of action in the same field.

Effects of Global Warming on the Distribution of Overwintering Pomacea canaliculata (Gastropoda: Ampullariidae) in Korea

  • Bae, Mi-Jung;Kwon, Yong-Su;Park, Young-Seuk
    • Korean Journal of Ecology and Environment
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    • v.45 no.4
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    • pp.453-458
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    • 2012
  • The golden apple snail, Pomacea canaliculata, is a freshwater snail native to tropical and subtropical South America. The species was introduced into Korea as a human food source in 1983 and was first applied as a weed control agent for the paddy fields in 1992. As the snail is well known as an environmentally friendly biological control agent for weeds, the area of cultivation in which the golden apple snail is used for biological control has been enlarged substantially each year. Currently, the species is observed in open water courses. It is possible that the snail may overwinter in these open water courses and may become a serious pest, as is already the case in many Asian countries. In this study, we determined the status of the overwintering golden apple snail based on a literature survey and investigated the potential distribution area of the snail, as a result from global warming in Korea. The potential distribution area of the overwintering golden apple snail would be enlarged under the influence of global warming; ranging from 45.5% of South Korea's land area in the 2020s to 88.4% in the 2080s.

Present Status and Future Prospect of Environment Agriculture in Daeho Reclain ed Saline Area (대호간척지의 환경농업 추진현황과 발전방향)

  • Chae Je-Cheon
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2001.09a
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    • pp.72-90
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    • 2001
  • Environment agriculture carried out from 1999 in Daeho reclaimed saline area, located in central east cost of Choongnam Korea, resulted in dramatic reduction of amount of nitrogen fertilizer and application times and amount of pesticides. The ecological status of Daeho reclaimed saline area was considered to still very sound from the results of ecological survey on flora and fauna. However, it was desirable to adapt precision agriculture for production of high eating quality of rice and preservation of Daeho ecosystem. Especially, precise application of nitrogen and phosphorus fertilizer was recommendable for prevention of water pollution in environment rice cultivation by duck or mud snail or crab. The bioefficacy of Scirpus maritimus and Echinochloa crus-galli in paddy field of environment rice cultivation by duck or mud snail or crab in Daeho reclaimed saline area was revealed very low. Therefor, it was concluded that the pre-measures of reduction of natural weed population were necessary for successful environment agriculture. The most desirable and ideal environmentally sound agriculture in Daeho reclaimed saline area was performance of crop rotation, introduction of legume crops and green manure crops, and also, simultaneous management of crop production and animal husbandry for smooth flow of energy cycle within the closed Daeho ecosystem.

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Competition between Transplanted Lowland Rice and Weeds as Affected by Plant Spacing and Rice Cultivar Having Different Culm Length (수도품종(水稻品種)의 간장차이(稈長差異)가 잡초(雜草)와의 경쟁력(競爭力)에 미치는 영향(影響))

  • Kim, S.C.;Lee, S.K.;Park, R.K.
    • Korean Journal of Weed Science
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    • v.1 no.1
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    • pp.44-51
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    • 1981
  • An experiment was conducted to obtain the basic information about competitive ability of rice against weeds as affected by culm length at the Yeongnam Crop Experiment Station, Office of Rural Development in 1980. More weeds were harvested from the plot of short statured cultivar, Manseogbyeo compared to the plot of Cheongcheongbyeo that was approximately 10cm taller than Manseogbyeo regardless of planting density variables. Weeds also decreased as rice population increased from $30{\times}15cm$, $40{\times}(10{\times}10cm)$ and to $10{\times}10cm$, in order. The degree of weed suppression and floristic composition was varied depending upon plant spacing and weeding regime subjected at the previous year. The degree of weed suppression became increased with increasing rice population. The degree of weed suppression at the $10{\times}10cm$ plant spacing showed as high as hand weeding subjected in the previous year. However, in terms of floristic composition, Scirpus hotarui Roxb. became dominant when rice had cultivated at $10{\times}10cm$ plant spacing in the previous year while S. hotarui and Sagittaria pygmaea Miq. were both important in the hand weeding plot. The highest grain yield of rice showed at the $10{\times}10cm$ plant spacing while no significant difference was observed between $40{\times}(10{\times}10cm)$ and $30{\times}15cm$ plant spacings for both weeding regimes and both cultivars. However, response of grain yield to weeding regime was differed in two cultivars. For Manseobgyeo, significant grain yield decreased in no weeding plot regardless of plant spacing variables. But in case of Cheongcheongbyeo, grain yield reduction was only recognized at the $30{\times}15cm$ plant spacing. Based on these result it could be concluded that Cheongcheongbyeo (10cm taller in height) seemed to be more competitive against weeds than Manseogbyeo.

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Herbicidal Effect on Perennial Paddy Weed Sagittaria and Eleocharis (답(畓) 다년생잡초(多年生雜草) 올미 및 올방개에 대한 제초체(除草劑) 작용성(作用性)에 관한 연구(硏究))

  • Chang, Y.H.;Kusanagi, Tokuichi
    • Korean Journal of Weed Science
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    • v.2 no.1
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    • pp.41-46
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    • 1982
  • Herbicidal effectivity on perennial paddy weeds such as Sagittaria pygmaea Miq. and Eleocharis kuroguwai Ohwi was evaluated. Herbicides used were butachlor [2-chloro-2, 6-dietyl-N(butoxymethyl)-acetanilide], benthiocarb [S-(4-chlorobenzy)-N, N-diethyl-thiocarbamate], molinate (S-ethyhexahyaro-l-Hazpine-carbothiate], SW-751, Chlormethoxynil (2.4-dichlorophenyl-3-methoxy-4-nitrophenyl-ether), CNP (2.4.6-trichlorophenyl-4-nitrophenylether),oxadiazon [2-tertbutyl-4-(2.4-dichloro-S-isopropoxyphenyl)-5-OXO-1.3.4-Oxadiazoline], dinuron [1-dimethyl-benthyl)-3-pheratrylurea], bentazon [3-isopropyl-IH-2.1.3-benzothiadiazine-(4)3H-one-2.2-dioxide], ACN (3-chloro-2-amino-l.4-naphthoquinone), MCPB [4-(2-methyl-4chlorophenoxy), butyric acid], 2.4-D (sodium 2.4-dichlorophenoxy acetic acid), MCP) sodium 2-methyl-4-chlorophenoxy acetic acid), SST-5, TH 63. Graszin D (Bentazon/2.4-D) and Graszin M (Bentazon/MCP) Herbicidal effectivity was divided into three types. Type I was the complete control both leaf and tuber, and SW-751 was belonged to this type. Type II was the partial control that exhibit complete control within certain period after herbicide application. After a certain period, however, the lateral bud have the germinability and grow normally, there after. Chloromethoxynil, CNP, ACN, and Oxadiazon were belonged to this group. Type III was no control at all. For E. kuroguwai, application of CNP, Chloromethoxnil, Oxadiazon and SW-751 gave good control in the early stage shile 2.4-D, MCP, bentazon and glaszin-D controlled well the intermediate stage application. Based on this results, E. kuroguwai can be controlled by herbicide application either in the early stage or in the intermediate stage.

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Change of Efficacy and Phytotoxicity of Paddy Herbicide under Temperature Rise (온도상승에 따른 논 제초제의 약효 및 약해 변동)

  • Park, Tae-Sun;Hwang, Jae-Bok;Bae, Hee-Soo;Park, Hong-Kyu;Lee, Gun-Hwi
    • Weed & Turfgrass Science
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    • v.6 no.3
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    • pp.203-211
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    • 2017
  • This study was conducted to investigate the phytotoxicity of main rice varieties and control efficacy of HPPD inhibitor to major paddy weeds at the time of temperature rise due to climate change. Phytotoxicity of herbicide to rice was increased as temperature was increased, and more severe in root than shoot. The phytotoxicity of japonica rice cultivars for the rice were mild enough to recover. However, glutinous rice, super high yield rice, and Tongil rice varieties were damaged enough to decrease the yield. Shindongjinbyeo transplanted by June 15, showed phytotoxicity enough to recover. However, in the rice field on June 30 and on July 15, the rice showed a remarkable inhibition. The control effect of Monochoria vaginalis and Scirpus juncoides was more than 90% under the temperature condition controlled artificially. However, Echinochloa oryzicola was controlled 40% at $27.5^{\circ}C$, which is a high temperature condition. In rice fields with different transplanting times, annual weeds except for E. oryzicola were highly controlled by 90% or more regardless of the time of transplanting.

Growth Habits of Scirpus planiculmis F. Schmidt in Poldered Paddy Field (간척지(干拓地) 우점잡초(優占雜草) 새섬매자기(Scirpus planiculmis F. Schmidt)의 생육습성(生育習性))

  • Lee, K.S.;Han, K.H.;Park, S.H.;Choi, S.Y.
    • Korean Journal of Weed Science
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    • v.11 no.2
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    • pp.111-116
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    • 1991
  • This studies were conducted to get the basic information on the growth habits of Scirpus planiculmis F. Schmidt for control in poldered paddy field. The distribution of corm was about 16% in 0-5cm, 66% in 5-8 cm. 18% in 8-10cm depth of underground. The mean depth of total corm distribution was about 6.51cm. Number of rhizomes and dormant buds per corm were one to four, respectively. Number of rhizomes. dormant buds and total buds(rhizome+dormant bud) were 2.34, 2.85 and 5.20, respectively. The phyllotaxy of S. planiculmis was 1/3 and bracteal leaf were showed from first to 4th leaves. The period of propagation to 100 plants from emergence was 58.52 and 48 days for corm seeded on March 25th, b4ay 7th and June 6th respectively. Days to emergence of S. planiculmis from emergence of previous plant was gradually shorted. as order of propagation from corm seeded progressed. The other side, length of rhizome, plant height and diameter of culm was increased. The plant height of S. planiculmis was higher than rice plant from early stage in rice direct seeding culture, and from 30 dats after transplanting in rice transplanting culture. Speed of propagation was faster in rice direct seeding culture than in rice trasplanting culture.

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A Study on Transition of Rice Culture Practices During Chosun Dynasty Through Old References IX. Intergrated Discussion on Rice (주요(主要) 고농서(古農書)를 통(通)한 조선시대(朝鮮時代)의 도작기술(稻作技術) 전개(展開) 과정(過程) 연구(硏究) - IX. 도작기술(稻作技術)에 대(對)한 종합고찰(綜合考察))

  • Guh, J.O.;Lee, S.K.;Lee, E.W.;Lee, H.S.
    • Korean Journal of Weed Science
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    • v.12 no.1
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    • pp.70-79
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    • 1992
  • From the beginning of the chosun dynasty, an agriculture-first policy was imposed by being written farming books, for instance, Nongsajiksul, matched with real conditions of local agriculture, which provided the grounds of new, intensive farming technologies. This farming book was the collection of good fanning technologies that were experienced in rural farm areas at that time. According to Nongsajiksul, rice culture systems were divided into "Musarmi"(Water-Seeded rice), /"Kunsarmi"(dry-seeded rice), /transplanted rice and mountainous rice (upland rice) culture. The characteristics of these rice cultures with high technologies were based of scientific weeding methods, improved fertilization, and cultivation works using cattle power and manpower tools systematically. Reclamation of coastal swampy and barren land was possible in virtue of fire cultivation farming(火耕) and a weeding tool called "Yoonmok"(輪木). Also, there was an improved hoe to do weeding works as well as thinning and heaping-up of soil at seeding stages of rice. Direct-seeded rice culture in flat paddy fields were expanded by constructing the irrigation reservoirs and ponds, and the valley paddy fields was reclaimed by constructing "Boh(洑)". These were possible due to weed control by irrigation waters, keeping soil fertility by inorganic fertilization during irrigation, and increased productivity of rice fields by supplying good physiological conditions for rice. Also, labor-saving culture of rice was feasible by transplanting but in national-wide, rice should not basically be transplanted because of the restriction of water use. Thus, direct-seeded rice in dry soils was established, in which rice was direct-seeded and grown in dry soils by seedling stages and was grown in flooded fields when rained, as in the book "Nongsajiksul". During the middle of the dynasty(AD 1495-1725), the excellent labor-saving farmings include check-rowing transplanting because of weeding efficiency and availability in rice("Hanjongrok"), and, nurserybed techniques (early transplanting of rice) were emphasized on the basis of rice transplanting ["Nongajibsung"]. The techniques for deep plowing with cattle powers and for putting more fertilizers were to improve the productivity of labor and land, The matters advanced in "Sanlimkyungje" more than in "Nongajibsung" were, development of "drybed of rice nursery stock", like "upland rice nursery" today, transplanting, establishment of "winter barly on drained paddy field, and improvement of labor and land-productivity in rice". This resulted in the community of large-scale farming by changing the pattern of small-farming into the production system of rice management. Woo-hayoung(1741-1812) in his book "Chonilrok" tried to reform from large-scale farmings into intensive farmings, of which as eminent view was to divide the land use into transplanting (paddy) and groove-seeding methods(dry field). Especially as insisted by Seo-yugo ("Sanlimkyungjeji"), the advantages of transplanting were curtailment of weeding labors, good growth of rice because of soil fertility of both nurserybed and paddy field, and newly active growth because rice plants were pulled out and replanted. Of course, there were reestimation of transplanting, limitation of two croppings a year, restriction of "paddy-upland alternation", and a ban for large-scale farming. At that period, Lee-jiyum had written on rice farming technologies in dry upland with consider of the land, water physiology of rice, and convenience for weeding, and it was a creative cropping system to secure the farm income most safely. As a integrated considerations, the followings must be introduced to practice the improved farming methods ; namely, improvement of farming tools, putting more fertilizers, introduction of cultural technologies more rational and efficient, management of labor power, improvement of cropping system to enhance use of irrigation water and land, introduction of new crops and new varieties.

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Development of Mixed Pesticides Containing Herbicide and Topdressing Fertilizer for Paddy Rice (벼 제초제(除草劑)와 분약비(分蘖肥) 혼합약제(混合藥劑)의 개발(開發))

  • Park, Yang-Ho;Lee, Byung-Moo;Park, Seung-Soon;Lee, In-Yong;Kim, Young-Koo;Park, Young-Sun
    • Korean Journal of Environmental Agriculture
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    • v.13 no.3
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    • pp.279-287
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    • 1994
  • To develop mixed pesticides of herbicide and topdressing fertilizer for paddy rice, twelve mixtures were formulated with combination of urea coated with different level of acrylic acid wax(AAW) and four herbicides, which were thiobencarb, pretilachlor, mefenacet + bensulfuron-methyl and mefenacet + bensulfuron-methyl + dymron, and effects of the mixtures for weed control, phytotoxicity and rice tillering were investigated in the laboratory and the field experiments. Release rates of active ingredient of herbicides in the distilled water were over 90% during 24 hours same as that of the reference herbicides. The release rates of nitrogen showed different patterns according to coated level of granular urea with acrylic acid wax. Optimum release rate of nitrogen as $NH_4-N$ was obtained by 5.5% AAW coating on urea for thiobencarb or pretilachlor mixture, and by 4.0% AAW coating on urea for mefenacet + bensulfuron-methyl or mefenacet + bensulfuron-methyl + dymron mixture. The pesticide active ingredients of the mixtures were stable, which showed $3.7{\sim}8.0%$ of degradation rate after 90 days of storage under $50^{\circ}C$. Effects on weed control of mixtures were acceptable for both annual and perennial weeds, while ACRI-M9213 mixture showed considerable phytotoxicity at double dose of standard. When treated the mixed pesticides to paddy rice, rice growth status including culm length, ear length, panicle number and polished rice yield exhibited no significant differences compared with the conventional treatment.

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