• Title, Summary, Keyword: herbicide

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The Analysis of Herbicide Penetration with Spray Deposit Characteristics on Plant Leaves (잎 표면의 분무입자 부착특성에 따른 제초제 침투성 분석)

  • 장영창
    • Journal of Biosystems Engineering
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    • v.25 no.4
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    • pp.287-292
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    • 2000
  • The herbicide penetration on weed leaves was spatially analyzed by using chlorophyll fluorescent emission and machine vision technique. Velvetleaf and metribuzin were used as experimental materials in the study. The herbicide spray images were obtained by a combinaton of a fluorescent dye and a UV lighting system. The herbicide penetration was analyzed by means of detecting chlorophyll fluorescent emission under blue-green lighting. According to the experiment results, the number and the size of spray droplets decreased with coverage increasing. The herbicide penetrated mainly along leaf veins and the time for complete penetration over the whole leaf was approximately 100 minutes after herbicide spraying. When the coverage of herbicide droplets on the surface of leaves increased, the speed of herbicide penetration also increased. This study suggested a way of characerizing herbicide spatial penetration and distribution in leaves.

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Effects of Sowing Methods after Herbicide Application on Forage Production and Botanical Composition in the Pasture Dominated Hypochoeris radicata (서양금혼초(Hypochoeris radicata) 우점 초지에서 제초제 처리 및 파종방법이 목초의 수량 및 식생에 미치는 영향)

  • 박남건;고서봉;이종언;진신흠
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.21 no.3
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    • pp.123-128
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    • 2001
  • This study was carried out to determine the effects of sowing methods after herbicide application on botanical composition, forage yield and chemical contents in the pasture dominated Hypochoeris radicata in Jeju area over two years. It was arranged as a randomized block design with five treatrnents(contro1: none, TI : herbicide application, T2 : herbicide application + oversowing, T3 : herbicide application + overdrilling, T4 : herbicide application + cultivation). In the pasture dominated Hypochoeris radicata, the herbicide (dicamba) treatments improved grass rate with orchardgrass and perennial ryegrass by 97%. The DM yield per ha were much higher(p<0.05) in T2(7,152kg), T3(7,608kg) and T4(8,010kg) than that of control. The chemical compositions of grass (% of DM basis) were not different among treatments, but the overdrilling and cultivation treatments tended to increase the forage crude protein(CP). These results indicate that oversowing or overdrilling after herbicide application can efficiently improve botanical compositions and forage productivity in the pasture dominated Hypochoeris radicata. (Key words : Herbicide, Sowing methods, Botanical composition, Forage production)

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Mechanisms of herbicide resistance in weeds

  • Bo, Aung Bo;Won, Ok Jae;Sin, Hun Tak;Lee, Jeung Joo;Park, Kee Woong
    • Korean Journal of Agricultural Science
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    • v.44 no.1
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    • pp.1-15
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    • 2017
  • In major field crops, synthetic herbicides have been used to control weeds worldwide. Globally, herbicide resistance in weeds should be minimized because it is a major limiting factor for food security. Cross resistance can occur with herbicides within the same or in different herbicide families and with the same or different sites of action. Multiple resistance refers to evolved mechanisms of resistance to more than one herbicide (e.g., resistance to both ALS-inhibitors and ACCase-inhibitors) and this resistance was brought about by separate selection processes. Target site resistance could occur from changes at the biochemical site of action of one herbicide. Non target site resistance occurs through mechanisms which reduce the number of herbicide molecules that reach the herbicide target site. There are currently 480 unique cases (species ${\times}$ site of action) of herbicide resistance globally in 252 plant species (145 dicots and 105 monocots). To date, resistance in weeds has been reported to 161 different herbicides, involving 23 of the 26 known herbicide sites of action. Finally, it can be concluded that we can protect crops associated to herbicide resistant weeds by applications of biochemical, genetic and crop control strategies.

Establishment of Herbicide Screening Methods for Reed (Phragmites communis Trin.) Control - II. Tetrapion Effect (갈대(Reed, Phragmites communis Trin.)의 방제를 위한 제초제 스크리닝방법의 확립 - II. Tetrapion 의 효과)

  • Hwang, I.T.;Choi, J.S.;Lee, H.J.;Kim, K.J.;Cho, K.Y.
    • Korean Journal of Weed Science
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    • v.16 no.1
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    • pp.28-35
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    • 1996
  • Tetrapion(2,2,3,3-tetrafluoropropionate sodium) has commonly been used for reed(Phragmites communis Trin.) control in uncultivated areas, especially in Japan. As an attempt to establish the screening system for selective herbicide controlling reed, tetrapion was tested as a standard herbicide to various weeds and crops including rice in a greenhouse. Symptoms of yellowing, twisting, stunting, and necrosis were observed in the herbicide-treated plants. The herbicide caused a severe damage on all crops examined, except cotton. Both direct seeded and transplanted rice were also sensitive to the herbicide. Its herbicidal activity was generally higher on grass weeds than on broadleaf weeds. It had a higher herbicidal activity with preemergence treatment than with postemergence treatment. In addition, field and greenhouse experiments were conducted to examine the effect of the herbicide on reed control. Its effect varied with the soil type of the treated field and the growth stage of reed. A relatively high dosage of the herbicide was required to control reed. It had an almost same effect on fairygrass(Miscanthus sinensis Anderss) as on reed. However, reed grown in a greenhouse was effectively controlled by the herbicide, having more effect with preemergence treatment than with postemergence treatment as observed in other plants treated with the herbicide. In conclusion, tetrapion has a great potential as a standard herbicide during the herbicide screening for selective reed control.

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Studies on the herbicide Application for Use in Pasture Establishment by Overseeding II. Influence of herbicide residue in soils on the growth of introduce pasture grasses (겉뿌림 초지조성지에서 제초제 처리방법에 관한 연구 II. 제초제의 토양 잔류성과 목초의 생육장해)

  • 김정갑
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.11 no.3
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    • pp.162-168
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    • 1991
  • Iterbicide resduc. cauicd ~rljul-y to ovcrsown pasture grasses \\hen herbicide appliccl for use in pasturc est;~blish~nt~nt lo gro~vth contro! ol n;rtivc ~r ~:cds and shrubs. 'l'hih L~sperirnel~t was conducted to cv;lluati. (he herbicidr residue anti its ph!:totosical ~riiiuence on the growth of introtluccd pasturts species. Esperimcmtal soils was treated with buthitlazolc, ~ o d l ~ l m chlorate, glyphosatc. U-46 anti paraquat each at twt) applici~tion rates. Lhcf~1i.s glowl~mlc~ including othrr pasture grasses and le~urnes were evaluatrd for tolerance to herbicide. IIerbicide residue in the amount ot injury caused to introduced pasture grasses was found in order of buthidazole, sodium chlorate, U-46 and glyphosate. Euthidazole was not available for use in pasture establishment because of their long persist of toxic herbicide residues. A great stand redl~ction of subseq ~ ~ c n t oversown pastures was also observed In sodium chlorate treatment. However, normal vegetative stand and grass production was obtained, when thc pasture grasses seeded 45-60 days later herbicide treatments. Glyphosate did not affect subsequent oversown pasture species in both grasses and legumes. fistuccr arundinc~cea and Pou pratensis were the most tolerant pasture species to herbicide residue while 7'rzfi,lium pyatense and Medicugo suti~u showed a wsceptible response regardless of herbicide.

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Development and Application Performance of a Granular Herbicide Applicator Attached to Rice Transplanter (승용 이앙기 부착형 제초입제 살포기 개발과 살포성능)

  • 김진영;박석호;최덕규;구연충
    • Journal of Biosystems Engineering
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    • v.23 no.4
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    • pp.319-326
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    • 1998
  • A herbicide applicator attached to a rice transplanter was developed to perform herbicide application and transplanting simultaneously. The prototype machine was composed of herbicide tank, discharge device, spinner, scattering plate and power drive. The application rate of the machine could be adjusted from 10 to 30 kg/㏊ and the application swath was 1.8m. According to the field test, application uniformity showed the range of 13.6~43.9% in terms of CV(coefficient of variation) depending on the spinner speed, application height and shape of diffuser. The best uniformity could be achieved with the spinner speed of 30.8m/s and application height of 20cm. Field efficiency of the prototype was 4.7hr/㏊. Transplanting machine has field efficiency of 4.6hr/㏊ in Korea. By attaching the herbicide applicator, field efficiency became lowed only by 0.1hr/㏊, which was counted for filling time of herbicide. Simultaneous operation of transplanting and herbicide application had a of labor saying. The weed control efficacy was measured to be 96% in field when AC140 + Stomp and Londax + YRC was applied at the 65th day after transplanting. Nonanmae was treated by manual application to be compared to.

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Use of Herbicides and the Residues (제초제 사용과 잔유)

  • 문영희;전재철
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.21-38
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    • 1999
  • Herbicide is an essential agricultural chemical in the modern agriculture. Due to its bioactivity, however, risk of herbicide use against non-target organisms should be seriously considered. Among the unfavorable aspects given by herbicide, the residue is the most important because herbicide residue in soil and agricultural product is closely related to human safety. The residue in soil and crop is dependent on conditions of soil, weather, herbicide use and crop cultivation, etc. In general, the residue in soil or agricultural product in Korea is known to be not serious at this moment, except for some problems like carry-over effect on succeeding crops. To secure safety of herbicide use for the health, soil ecology and other environment, researches on herbicide residue including monitoring survey should be done more frequently and extensively. Safety guide for herbicide usage should be kept by farmers and development of long toxic herbicide should be accelerated.

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Occurrence and Distribution of Herbicide Resistant Weeds in the Paddy Field of Chungnam Province (충남지역에서의 제초제 저항성 논 잡초 발생 및 분포)

  • Won, Ok Jae;Jia, Wei Qiang;Lee, Jeung Joo;Kim, Jin-Won;Lee, Jeongran;Park, Kee Woong
    • Weed & Turfgrass Science
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    • v.7 no.3
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    • pp.201-208
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    • 2018
  • This study was conducted to investigate the occurrence and distribution of herbicide resistant weeds at rice fields in Chungnam province of Korea in 2017. Herbicide-resistant weeds occurred in 64,782 ha, which comprise 47.0% of the total paddy field area of Chungnam province. The infested area of herbicide resistant weeds was estimated in Seosan-si (11.9%), Nonsan-si (11.1%), Dangjin-si (10.9%), Boryeong-si (9.2%) and Asan-si (7.8%). The most dominant herbicide resistant weeds in rice fields were Monochoria vaginalis, followed by Lindernia dubia, Schoenoplectus juncoides, Echinochloa oryzicola, Cyperus difformis and Sagittaria trifolia. Herbicide resistant M. vaginalis, L. dubia, and S. juncoides occurred throughout Chungnam province, and herbicide resistant S. trifolia was only found in Dangjin-si. Compared with the 2011 survey, the infested area of herbicide-resistant weeds decreased, but the incidence rates were similar. The herbicide rotation with different modes of actions across growing seasons is recommended to control herbicide-resistant weeds in the infested fields. It is necessary to monitor herbicide resistance regularly and conduct integrated herbicide resistance management in this area.

Studies on the Analytical Methods and Quantity of Residual 2,4-D in Imported Fruits (수입 과일중 2,4-D의 잔류분석법 및 잔류량 연구)

  • 홍무기
    • Journal of Food Hygiene and Safety
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    • v.9 no.2
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    • pp.89-94
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    • 1994
  • A simple, safe, and sensitive gas chromatographic method using packed column and electron capture detector to analyze 2, 4-D herbicide in imported lemon, grapefruit, and orange was described and its usefulness evaluated. In this scheme of analysis the acid herbicide was converted into its alkyl esters by an one-step reaction prior to analysis. The herbicide in the fruits was extracted with ethyl acetate and partitioned against dichloromethane for purification, and the extracts finished partitioning were derivatized with alcohol, using sulfuric acid as a catalyst to form the corresponding alkyl derivatives. The analytical scheme studiedwas found to be applicable for the herbicide in the fruits without a column clean-up procedure. The mean recoveries of the herbicide for lemon samples fortified at 0.1 mg/kg and 1.0 mg/kg were 93% and 95%, respectively. The detection limit was 0.5 $\mu\textrm{g}$/kg for 2.4-D methyl ester.

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Differential Responses of Two Freshwater Cyanobacteria, Anabaena variabillis and Nostoc commune, to Sulfonylurea Herbicide Bensulfuron-methyl

  • KIM JEONG-DONG;LEE CHOUL-GYUN
    • Journal of Microbiology and Biotechnology
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    • v.16 no.1
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    • pp.52-56
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    • 2006
  • The effect of bensulfuron-methyl on the nontargeted cyanobacteria was greater on A. variabillis than N. commune. Both A. variabillis and N. commune were initially able to utilize low concentrations of the herbicide, bensulfuron-methyl, whereas higher concentrations of bensulfuron-methyl or the hydrolyzed products of the herbicide were found to be toxic. Growth and photosynthesis inhibitions of over $50\%$ were observed, when 8 to 10 ppm of the herbicide was applied. Nitrogenase activities of the cyanobacteria were decreased by $94-98\%$ in A. variabillis and by $85-86\%$ in N. commune after 24 h of incubation with 10 ppm and 20 ppm of bensulfuron-methyl. Nitrogenase activities were also inhibited by the addition of ammonium salts as low as 0.05 mM. Furthermore, the toxic effect of the herbicide was the highest at pH 4-6, showing approximately $42-60\%$ toxicity, whereas much lower toxicity $(9-28\%)$ was observed at higher pH of 7-10, due to base-catalyzed hydrolysis of bensulfuron-methyl.