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Sample records for low-impact selective herbicide

  1. selective herbicide glyphosate

    African Journals Online (AJOL)

    Aghomotsegin

    2016-05-04

    May 4, 2016 ... concentrations of the test chemical at 0.625, 1.25, 2.5, 5 and 10 mg/L, respectively. The percentage growth rate ... production, processing, storage, transport or marketing of ... Herbicides commonly known as weed-killers are.

  2. Selectivity of herbicides in crambe crop

    Directory of Open Access Journals (Sweden)

    Guilherme Sasso Ferreira Souza

    2014-02-01

    Full Text Available The low productivity of crambe can be associated with many factors, among these, the competition with weeds, which reduces the yield, harvest affects and contributes to the increase in seed moisture. Therefore, this study aimed to evaluate the tolerance of crambe plants cv. FMS Brilhante to herbicides applied in preplant incorporated (PPI, preemergence (PRE, and postemergence (POST. The study was installed in a green-house and the treatments consisted of the herbicide application in: pre-plant incorporated ofdiclosulam, flumetsulam, metribuzin, and trifluralin;preemergence applicationof atrazine, diclosulam, diuron, flumetsulam, metribuzim, S-metolachlor, sulfentrazone, and trifluralin; and postemergence application ofbentazon, carfentrazone-ethyl, clefoxydim, cletodim + fenoxaprop-p-ethyl, ethoxysulfuron, fomesafen, fluazifop-p-butyl, flumioxazin, halosulfuron, imazamox, imazapic, lactofen, nicosulfuron, oxadiazon, quinclorac, and setoxydim. Visual evaluations of phytotoxicity on crambe plants were realized after applications, the seedlings were counted and the height and plant dry matter were determined in the end of the evaluation period. In conditions where the studies were conducted, we can conclude that only the trifluralin application in PRE and the application of clefoxidim+fenoxaprop-p-ethyl, fluazifop-p-butyl, quinclorac, setoxydim and clefoxydim in POST showed selectivity and potential use for FMS Brilhante crambe cultivar.

  3. In vitro screening of selected herbicides on rhizosphere mycoflora ...

    African Journals Online (AJOL)

    In vitro screening of five selected herbicides at different concentrations on rhizosphere mycoflora from yellow pepper (capsicum annum L var. Nsukka yellow) seedlings at Nsukka were investigated. The herbicides employed for this study were Paraquat, Glyphosate, Primextra, Atrazine and Linuron. The isolated rhizosphere ...

  4. Selective Herbicides for Cultivation of Eucalyptus urograndis Clones

    Directory of Open Access Journals (Sweden)

    Patrick J. Minogue

    2015-01-01

    Full Text Available Competition control is essential for successful eucalyptus plantation establishment, yet few selective herbicides have been identified. Five herbicides, flumioxazin, imazamox, imazapic, oxyfluorfen, and sulfometuron methyl, were evaluated for selective weed control in the establishment of genetically modified frost tolerant Eucalyptus urograndis clones. Herbicides were applied at two or three rates, either before or after weed emergence, and compared to a nontreated control and to near-complete weed control obtained with glyphosate directed sprays. Applications prior to weed emergence were most effective for weed control and, with the exception of imazapic, all resulted in enhanced eucalyptus growth relative to the nontreated control. Among postemergent treatments, only imazamox enhanced stem volume. Among selective herbicide treatments, preemergent 2240 g ha−1 oxyfluorfen produced the best growth response, resulting in stem volume index that was 860% greater than the nontreated control, although only 15% of the volume index obtained with near-complete weed control. Imazapic was the most phytotoxic of all herbicides, resulting in 40% mortality when applied preemergent. Survival was 100% for all other herbicide treatments. This research found the previously nontested herbicides imazamox and imazapic to be effective for selective weed control and refined application rate and timing of five herbicides for use in clonal plantations.

  5. SELECTIVITY OF DIFFERENT HERBICIDES TO COWPEA

    Directory of Open Access Journals (Sweden)

    Francisco Aires Sizenando Filho2

    2013-12-01

    1.5 = recommended rate + half the recommended rate. At the end of the experiment it was found that: the cowpea showed phytotoxicity to use herbicide among 14 and 21 AAD; the herbicides diuron and metolachlor showed a rate "middle" in control weed, while the pendimethalin wasn't efficient for those function.

  6. Rapeseed with tolerance to the non selective herbicide glufosinate ammonium

    Energy Technology Data Exchange (ETDEWEB)

    Rasche, E. [Hoechst Schering AgrEvo GmbH, Frankfurt am Main (Germany)

    1998-12-31

    Weed control with herbicides is essential to grow rapeseed. Glufosinate Ammonium is used as a non selective herbicide successfully in many countries for over 10 years. It conforms well with ever increasing safety standards for human beings, animals and the environment. The tolerance of rapeseed and other crop plants was achieved by genetic modification. A resistance gene (PAT or BAR) was transfered into previously susceptible rapeseed plants. This new approach allowed the development of Glufosinate Ammonium as an almost ideal selective herbicide. In cooperation with major seed companies and by own breeding programmes new Glufosinate tolerant rapeseed varieties and hybrids are developed. Data on metabolism, toxicity, residues, efficacy etc. were generated to get registration for the selective herbicide use. In addition various studies were done for safety assessments of the PAT gene and the modified rapeseed. In spring 1995 Canadian authorities granted worldwide the first approvals for the selective use of Glufosinate Ammonium (trademark Liberty) and Glufosinate tolerant (trademark and logo Liberty Link) spring rapeseed (Canola). After a successful launch in 1995 about 150.000 ha of Liberty Link Canola were grown and treated with Liberty in 1996. The Liberty Link Canola growers were very well satisfied. In a grower survey 84% stated that they will definitely use the Liberty Link System again. In Europe registrations for Glufosinate Ammonium as a selective herbicide and for the first Glufosinate tolerant rapeseed varieties are expected in the course of 1997. The Liberty Link System will be launched in rapeseed most probably in 1998. (orig.)

  7. Selectivity of herbicides in Camelina (Camelina sativa (L. Crtz.

    Directory of Open Access Journals (Sweden)

    Scheliga, Maria

    2016-02-01

    Full Text Available Camelina (Camelina sativa (L. Crtz. is a cruciferous plant. As an oilseed crop camelina is mainly grown for oil production. After the 1960s, however, the cultivation has become less important. Only in recent years, interest in this culture was awakened in the search for new sources of omega 3 fatty acids, natural antioxidants and a potential crop for the production of biofuels. The use of camelina oil for different purposes within the framework of the material use of renewable raw materials is of particular interest due to the high levels of linoleic and linolenic acid. For the establishment of camelina as a crop in agricultural crop rotation systems weed control should not be disregarded despite the rather good competitive ability against weeds. Based on greenhouse experiments a field trial in 2015 with different herbicide strategies was carried out. Besides Butisan Top (metazachlor + quinmerac, Devrinol FL (napropamide and Stomp Aqua (pendimethalin and also Betasana SC (phenmedipham has been tested in various amounts and combinations. Using assessments to weed density and herbicide tolerance different herbicide strategies were compared with each other. Though, it is difficult to find a compromise between satisfactory herbicidal effect and a slight injury to the crop plant. The herbicide selection, the application rate and the combination of different herbicides have an effect on the crop. To confirm the data obtained further tests are necessary.

  8. Selectivity and stability of new herbicides and herbicide combinations for the seed yields of some field crops I. Effect at Coriander (Coriandrum Sativum L.)

    OpenAIRE

    G. Delchev

    2016-01-01

    Abstract. . The research was conducted during 2013 – 2015 on pellic vertisol soil type. Under investigation was Bulgarian coriander cultivar Lozen 1 (Coriandrum sativum L.). The purpose of the investigation was to establish the selectivity and stability of some herbicides, herbicide combinations and herbicide tank mixtures on the coriander. Factor A included the years of investigation. Factor B included no treated check, 6 soil-applied herbicides – Tendar EC, Silba SC, Sharpen 33 EC,...

  9. Weed supression by smother crops and selective herbicides

    Directory of Open Access Journals (Sweden)

    Severino Francisco José

    2004-01-01

    Full Text Available Using a smother crop is thought to suppress weed density and to add other beneficial effects in sustainable agricultural systems. Weed suppression ought to be considered an essential component of integrated weed management. However, very little is known about the effects of green manure plants on weeds. This study evaluated the influence of three green manure species on weed suppression and selectivity of herbicides. A field experiment was designed to determine the effect of the green manure species Crotalaria juncea, Arachis pintoi and pigeon pea on the weeds Brachiaria decumbens, guineagrass and hairy beggarticks, and on the natural weed infestation in the inter rows area of an avocado orchard. The weed species were suppressed differently by each green manure species. Soil samples collected from the field experiment presented a residual effect, of at least 30 d, in suppressing weed seed bank recruitment; this residual effect was caused by the residues of the green manure present in the soil. When the green manure was incorporated into the top 5 cm of soil or left on the surface, in a greenhouse experiment, the emergence of weed seeds was significantly inhibited, depending on the species, and on the amount and depth of green manure incorporation. Greenhouse experiments indicate that pre-emergence herbicides cause lower phytotoxicity than post-emergence Arachis pintoi. Smother crops using green manure species, when well established in an area, provide additional weed control to the cropping system and are effective and valuable tools in integrated weed management.

  10. Selectivity and stability of vegetation-applied herbicides in cotton (Gossypium hirsutum L.

    Directory of Open Access Journals (Sweden)

    T. Barakova

    2016-06-01

    Full Text Available Abstract. An experiment was carried out during 2013 – 2015 in the experimental field of the Field Crops Institute, Chirpan, with two cotton cultivars − Helius and Darmi (Gossypium hirsutum L.. Herbicides: Goal 2 E, oxyfluorfen (80 ml/da; Linuron 45 SC, linuron (200 ml/da; Wing-P, pendimethalin + dimethenamid (400 ml/da; Merlin 750 WG, isoxaflutol (5 g/da; Bazagran 480 SL, bentazone (150 ml/da were investigated. They were treated separately or combined with growth regulator Amalgerol (500 ml/da or foliar fertilizer Lactofol O (500 ml/da in the budding stage of the cotton. It was established that selectivity is the lowest in the two cotton cultivars with herbicides Linuron 45 CK and Merlin 750 WG. The purpose of this investigation was to establish the selectivity and stability of some herbicides and their tank mixtures on the cotton by influence of different meteorological conditions. It has been found that the highest phytotoxicity on cotton is given the vegetation-applied herbicides Merlin and Linuron. Foliar fertilizer Laktofol O reduces phytotoxicity of herbicides Goal, Wing, Merlin and Bazagran in two cotton cultivars. Herbicides Wing and Bazagran have excellent selectivity for the two cotton cultivars – Helius and Darmi. The highest yield was obtained by vegetation treatment with herbicide Bazagran, followed by herbicides Wing and Goal. Tank mixtures of Goal, Bazagran and Wing with Laktofol, followed by those with Amalgerol are technologically the most valuable. They combine high yield with high stability over the years. Аlone application of herbicides Linuron and Merlin and their tank mixtures with Amalgerol and Laktofol have low estimate.

  11. Response of soil microbiota to selected herbicide treatments.

    Science.gov (United States)

    Roslycky, E B

    1977-04-01

    Recommended concentrations of paraquat alone and its combination with each of linuron, diuron, atrazine, simazine, and simazine plus diuron exerted little effect on total populations of bacteria, actinomycetes, and fungi in Fox sandy loam under laboratory and simulated field conditions in 66 and 77 days, respectively. Respiration of the total microbiota in soil suspension was afeected by the combinations as well as individual herbicides in various concentrations. Yet, the inhibition of the O2 uptake by any of these herbicides, including some extreme concentrations, was not permanent, indicating adaptation, or suppression of specific organisms. Only linuron in concentrations up to 20 microng/ml stimulated respiration of the soil.

  12. Residual herbicide study on selected Hanford Site roadsides

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.L.; Kemp, C.J.; Sackschewsky, M.R.

    1993-08-01

    Westinghouse Hanford Company routinely treats roadsides with herbicides to control undesirable plant growth. An experiment was conducted to test perennial grass germination in soils adjacent to roadways of the Hanford Site. The primary variable was the distance from the roadside. A simple germination test was executed in a controlled-environment chamber to determine the residual effects of these applications. As expected, the greatest herbicide activity was found directly adjacent to the roadway, approximately 0 to 20 ft (0 to 6.3 m) from the roadway.

  13. Selective isolation and screening of fungi with herbicidal potential ...

    African Journals Online (AJOL)

    The respective fungal isolates were cultivated in modified Fries media under standard condition. The mycelia and the filtrate were extracted with ethyl acetate and the concentrated extract was evaluated for the herbicidal activity adopting leaf necrosis assay. Among the different isolates, extract prepared from A. alternata and ...

  14. Efficacy of selected herbicide formulations on sugarcane field weeds ...

    African Journals Online (AJOL)

    In continuation for the search of appropriate weed control strategy for sugarcane field weeds at the Unilorin Sugar Research Institute (USRI), Ilorin located at 8o 030' N; 4o 32' E , Nigeria. Field trials were laid out in a randomized complete block design during 2012 and 2013 growing seasons to evaluate four herbicide ...

  15. Selectable tolerance to herbicides by mutated acetolactate synthase genes integrated into the chloroplast genome of tobacco.

    Science.gov (United States)

    Shimizu, Masanori; Goto, Maki; Hanai, Moeko; Shimizu, Tsutomu; Izawa, Norihiko; Kanamoto, Hirosuke; Tomizawa, Ken-Ichi; Yokota, Akiho; Kobayashi, Hirokazu

    2008-08-01

    Strategies employed for the production of genetically modified (GM) crops are premised on (1) the avoidance of gene transfer in the field; (2) the use of genes derived from edible organisms such as plants; (3) preventing the appearance of herbicide-resistant weeds; and (4) maintaining transgenes without obstructing plant cell propagation. To this end, we developed a novel vector system for chloroplast transformation with acetolactate synthase (ALS). ALS catalyzes the first step in the biosynthesis of the branched amino acids, and its enzymatic activity is inhibited by certain classes of herbicides. We generated a series of Arabidopsis (Arabidopsis thaliana) mutated ALS (mALS) genes and introduced constructs with mALS and the aminoglycoside 3'-adenyltransferase gene (aadA) into the tobacco (Nicotiana tabacum) chloroplast genome by particle bombardment. Transplastomic plants were selected using their resistance to spectinomycin. The effects of herbicides on transplastomic mALS activity were examined by a colorimetric assay using the leaves of transplastomic plants. We found that transplastomic G121A, A122V, and P197S plants were specifically tolerant to pyrimidinylcarboxylate, imidazolinon, and sulfonylurea/pyrimidinylcarboxylate herbicides, respectively. Transplastomic plants possessing mALSs were able to grow in the presence of various herbicides, thus affirming the relationship between mALSs and the associated resistance to herbicides. Our results show that mALS genes integrated into the chloroplast genome are useful sustainable markers that function to exclude plants other than those that are GM while maintaining transplastomic crops. This investigation suggests that the resistance management of weeds in the field amid growing GM crops is possible using (1) a series of mALSs that confer specific resistance to herbicides and (2) a strategy that employs herbicide rotation.

  16. Selectivity and stability of herbicides and herbicide combinations for the grain yield of maize (Zea Mays L.

    Directory of Open Access Journals (Sweden)

    T. Barakova

    2016-09-01

    Full Text Available Abstract. The research was conducted during 2012 - 2014 on pellic vertisol soil type. Under investigation was cycloxydim tolerant maize hybrid Ultrafox duo (Zea mays L.. Factor A included the years of investigation. Factor B included no treated check and 3 soil-applied herbicides – Adengo 465 SC (isoxaflutol + tiencarbazon – 440 ml/ha, Wing P (pendimethalin + dimethenamid – 4 l/ha and Lumax 538 SC (S-metolachlor + terbuthylazine + mesotrione – 4 l/ha. Factor C included no treated check and 5 foliar-applied herbicides – Stellar 210 SL (topramezon + dicamba – 1 l/ha, Principal plus (nicosulfuron + rimsulfuron + dicamba – 380 g/ha, Ventum WG (foramsulfuron + iodosulfuron – 150 g/ha, Monsun active OD (foramsulfuron + tiencarbazon – 1.5 l/ha and Laudis OD (tembotrione – 2 l/ha. In addition to these variants by conventional technology for maize growing one variant by Duo system technology is also included in the experiment. It includes soil-applied herbicide Merlin flex 480 SC (isoxaflutole – 420 g/ha and tank mixture of antigraminaceous herbicide Focus ultra (cycloxydim - 2 l/ha + antibroadleaved herbicide Kalam (tritosulfuron + dicamba – 300 g/ha. It is found that herbicide combination of soil-applied herbicide Merlin flex with tank mixture Focus ultra + Kalam by Duo system technology leads to obtaining high grain yield. High yields of maize grain are also obtained by herbicide combinations Lumax + Principal plus, Lumax + Laudis and Wing + Principal plus. The most unstable are the non-treated check and single use of soilapplied herbicides Adengo, Wing and Lumax. Technologically the most valuable are herbicide combination Merlin flex + Focus ultra + Kalam by Duo system technology, followed by combinations of foliar-applied herbicides Principal plus and Laudis with soil-applied herbicides Adengo, Wing and Lumax by conventional technology. Single use of herbicides has low estimate due to must to combine soil-applied with foliar

  17. Cross-resistance to prosulfocarb + S-metolachlor and pyroxasulfone selected by either herbicide in Lolium rigidum.

    Science.gov (United States)

    Busi, Roberto; Powles, Stephen B

    2016-09-01

    Weeds can be a greater constraint to crop production than animal pests and pathogens. Pre-emergence herbicides are crucial in many cropping systems to control weeds that have evolved resistance to selective post-emergence herbicides. In this study we assessed the potential to evolve resistance to the pre-emergence herbicides prosulfocarb + S-metolachlor or pyroxasulfone in 50 individual field Lolium rigidum populations collected in a random survey in Western Australia prior to commercialisation of these pre-emergence herbicides. This study shows for the first time that in randomly collected L. rigidum field populations the selection with either prosulfocarb + S-metolachlor or pyroxasulfone can result in concomitant evolution of resistance to both prosulfocarb + S-metolachlor and pyroxasulfone after three generations. In the major weed L. rigidum, traits conferring resistance to new herbicides can be present before herbicide commercialisation. Proactive and multidisciplinary research (evolutionary ecology, modelling and molecular biology) is required to detect and analyse resistant populations before they can appear in the field. Several studies show that evolved cross-resistance in weeds is complex and often unpredictable. Thus, long-term management of cross-resistant weeds must be achieved through heterogeneity of selection by effective chemical, cultural and physical weed control strategies that can delay herbicide resistance evolution. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  18. Spray boom for selectively spraying a herbicidal composition onto dicots

    DEFF Research Database (Denmark)

    2012-01-01

    There is provided a method and spray boom for discriminating cereal crop (monocot) and weeds (dicots). The spray boom includes means for digitally recording an image of a selected area to be treated by a nozzle on the spray boom, whereby a plant material is identified based on a segmentation proc...

  19. Selectivity of Some Herbicides to Cocksfoot (Dactylis glomerata L., Grown for Seed Production

    Directory of Open Access Journals (Sweden)

    Tsvetanka Dimitrova

    2012-01-01

    Full Text Available The study was conducted to determine selectivity of some herbicides to cocksfoot(Dactylis glomerata L., and their influence on the seed production, during the years 2008-2010. The trial was set on the experimental field of the Institute of Forage Crops – Pleven, onslightly leached chernozem. As a result of the research the following was found: herbicidesArat (500 g/l dicamba + 250 g/l tritosulfuron at the dose of 100 ml/ha, Korida 75 VDG (750g/kg tribenuron-methyl – 15 g/ha and Cambio SL (320 g/l bentazon + 90 g/l dicamba –1250 ml/ha and Grasp 25SK (250 g/l tralkoxyidim + Atplus at rate of 1000 + 1000 ml/ha hadhigh selectivity to cocksfoot, applied at 2-4 leaf stage during establishing year of the stand,and until the stage of the beginning of shooting up in seed production year.Herbicide Topik 080EK (80 g/l clodinofop – propargyl + antidote at rate of 300 ml/ha,showed phytotoxic effect to D. glomerata and caused the reduction of seed and dry biomassproductivity.

  20. Primisulfuron herbicide-resistant tobacco plants: mutant selection in vitro by adventitious shoot formation from cultured leaf discs

    International Nuclear Information System (INIS)

    Harms, C.T.; DiMaio, J.J.; Jayne, S.M.; Middlesteadt, L.A.; Negrotto, D.V.; Thompson-Taylor, H.; Montoya, A.L.

    1991-01-01

    A simple procedure has been developed for the rapid and direct selection of herbicide-resistant mutant plants. The procedure uses adventitious shoot formation from suitable explants, such as leaf discs, on a shoot-inducing culture medium containing a toxic herbicide concentration. Resistant green shoots were thus isolated from tobacco (Nicotiana tabacum L.) leaf explants cultured on medium containing 100 μg 1−1 primisulfuron, a new sulfonylurea herbicide. Resistant shoots were recovered from both haploid and diploid explants after UV mutagenesis, as well as without mutagenic treatment. Three mutant plants of separate origin were further analyzed biochemically and genetically. Their acetohydroxyacid synthase (AHAS) enzyme activity was less inhibited by sulfonylurea herbicides than that of unselected, sensitive wild type plants. The extent of inhibition of the AHAS enzyme among the three mutants was different for different sulfonylurea and imidazolinone herbicides suggesting different sites were affected by each mutation. Herbicide tolerance was scored for germinating seedling populations and was found to be inherited as a single dominant nuclear gene. Adventitious shoot formation from cultured leaf discs was used to determine the cross tolerance of mutant plants to various herbicidal AHAS inhibitors. The usefulness of this rapid and direct scheme for mutant selection based on adventitious shoot formation or embryogenesis is discussed. (author)

  1. Selectivity and stability of herbicides and their tank mixtures for the seed yield of sunflower (Helianthus Annuus L.

    Directory of Open Access Journals (Sweden)

    G. Delchev

    2016-12-01

    Full Text Available Abstract. The research was conducted during 2012 – 2014 on pellic vertisol soil type. Under investigation were 4 sunflower hybrids (Helianthus annuus L.: hybrid Bacardy (an imitolerant hybrid by ClearField plus technology, hybrid Estiva (an imitolerant hybrid by ClearField technology, hybrid Sumico (a tribenuron-methyl tolerant hybrid by ExpessSun technology and hybrid Arizona (a hybrid by conventional technology. Factor A included the years of investigation. Factor B, herbicides and tank mixtures, included 20 rates. It includes 3 variants by ClearField plus technology, 5 variants by ClearField technology, 5 variants by ExpessSun technology and 7 variants by conventional technology. All variants are on herbicide Gardoprim plus gold 500 SC (Smetolachlor + terbuthylazine – 3.5 l/ha, which treated after sowing before emergence of the sunflower. It is found that the highest seed yield is obtained at herbicide tank mixture Pulsar plus + Stomp aqua by ClearField plus technology. Tank mixture Listego + Dash + Sharpen by ClearField technology and Express + Trend + Select super by ExpressSun technology also lead to obtaining high seed yields. The most unstable are secondary weed infested checks by the fourth technologies for sunflower growing which are treated with soil-applied herbicide Gardoprim plus gold only. Technologically the most valuable are herbicide combination Pulsar plus + Stomp aqua and herbicide Pulsar by ClearField plus technology, tank mixtures Listego + Dash + Sharpen and Listego + Dash by ClearField technology and Express + Trend + Select super and Express + Lactofol B + Select super by ExpressSun technology. Tank mixtures of herbicides Smerch, Pendigan, Wing, Raft, Pledge and Modown with Amalgerol premium by conventional technology have low estimates due to insufficient control of some weeds in sunflower crops.

  2. Selectivity and weed control efficacy of some herbicides applied to sprinkler irrigated rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Cavero, J; Zaragoza, C; Cirujeda, A; Anzalone, A; Faci, J M; Blanco, O

    2011-07-01

    Sprinkler irrigation can reduce the irrigation water needed to grow rice. However, most available information on weed control with herbicides is related to flood irrigated rice because this is the main growing method. Field experiments were conducted at Zaragoza (Spain) during two years to study weed control and tolerance of sprinkler irrigated rice to several herbicides. The main weeds were Atriplex prostrata Boucher ex DC., Cyperus rotundus L., Echinochloa crus-galli (L.) Beauv. and Sonchus oleraceus L. Rice cv Guadiamar was tolerant to preemergence (PRE) application of clomazone at 0.36 kg ha{sup -}1 and oxadiazon at 0.5 kg ha{sup -}1. PRE application of pendimethalin at 1.32 kg ha{sup -}1 combined with clomazone at 0.36 kg ha{sup -}1 decreased rice yield. Postemergence (POST) application of bentazon at 1.6 kg ha{sup -}1 + MCPA at 0.25 kg ha{sup -}1 did not injure rice but POST application of azimsulfuron at 0.025 kg ha{sup -}1 produced visual crop injury. Only treatments that controlled grassy weeds since rice was planted and by more than 80% at harvest time lead to acceptable rice yield (> 5,000 kg ha{sup -}1). Clomazone applied PRE at 0.36 kg ha{sup -}1 provided good control of grassy weeds (> 80%) and the highest rice yield, so it is recommended as a selective and efficacious PRE treatment for weed control of annual weeds in sprinkler irrigated rice. The perennial purple nutsedge was difficult to control at high plant densities (> 150 plants m{sup -}2) and the recommended herbicide is azimsulfuron applied at POST at 0.02 kg ha{sup -}1. (Author) 37 refs.

  3. Endocrine disruption of sexual selection by an estrogenic herbicide in the mealworm beetle (Tenebrio molitor).

    Science.gov (United States)

    McCallum, Malcolm L; Matlock, Makensey; Treas, Justin; Safi, Barroq; Sanson, Wendy; McCallum, Jamie L

    2013-12-01

    The role that endocrine disruption could play in sexual selection remains relatively untested, and although estrogens occur in insects, little information exists about their biological role in insect reproduction. Atrazine is a commonly applied herbicide that mimics estrogen in vertebrates. Tenebrio molitor were raised from egg to adult under a gradation of environmentally relevant atrazine exposures and a non-treated control. Atrazine was delivered in the drinking water ad libitum. Female T. molitor were provided with a choice between unrelated males raised under three levels of atrazine exposures. Female preference for males demonstrated a non-monotonic inverted U-shaped response to atrazine exposure. There was no significant difference between the control and the high exposure to atrazine. Excluding the control, female preference increased as exposure concentration increased. These results have important repercussions for nonlethal effects of endocrine disruption on populations, their capacity to interfere with sexual selection, and the role of estrogen in pheromone communication among insects.

  4. Seletividade de herbicidas para cebola em semeadura direta Selectivity of herbicides for onions in direct sowing

    Directory of Open Access Journals (Sweden)

    Lino R. Ferreira

    1999-04-01

    Full Text Available As plantas de cebola provenientes da semeadura direta, têm-se mostrado muito sensíveis aos herbicidas recomendados para a cultura transplantada, principalmente aqueles com ação sobre plantas daninhas dicotiledôneas. Os efeitos do fracionamento da dose dos herbicidas oxyfluorfen, ioxynil-octanoato, fluazifop-p-butil e sethoxydim foram avaliados em dois cultivares (Granex Ouro e Granex 33, no sistema de semeadura direta. A tolerância dos dois cultivares ao oxyfluorfen e ao ioxynil-octanoato aumentou com a idade das plantas e com o parcelamento das doses, aplicando-se doses menores no estádio de duas folhas. Sethoxydim e fluazifop-p-butil foram seletivos para a cultura, independente da dose inicial aplicada e do cultivar avaliado.The plants of onions, from direct sowing, have shown to be quite sensitive toward herbicides recommended for transplanted culture, especially those acting on dycotiledoneous weeds. The effects of dose fractionating of herbicides oxyfluorfen, ioxynil-octanoato, fluazifop-p-butil and sethoxydim were evaluated in two cultivars (Granex Ouro and Granex 33, in the direct sowing system. The tolerance of the two cultivars toward oxyfluorfen and ioxynyl-octanoato increased with the plants age and with the parceling of the doses, applying smaller doses in the two leaves stage. Sethoxydim and fluazifop-p-butyl were selective for the culture, regardless of the applied initial doses and the evaluated cultivar.

  5. Forward selection for multiple resistance across the non-selective glyphosate, glufosinate and oxyfluorfen herbicides in Lolium weed species.

    Science.gov (United States)

    Fernández, Pablo; Alcántara, Ricardo; Osuna, María D; Vila-Aiub, Martin M; Prado, Rafael De

    2017-05-01

    In the Mediterranean area, Lolium species have evolved resistance to glyphosate after decades of continual use without other alternative chemicals in perennial crops (olive, citrus and vineyards). In recent years, oxyfluorfen alone or mixed with glyphosate and glufosinate has been introduced as a chemical option to control dicot and grass weeds. Dose-response studies confirmed that three glyphosate-resistant Lolium weed species (L. rigidum, L. perenne, L. multiflorum) collected from perennial crops in the Iberian Peninsula have also evolved resistance to glufosinate and oxyfluorfen herbicides, despite their recent introduction. Based on the LD 50 resistance parameter, the resistance factor was similar among Lolium species and ranged from 14- to 21-fold and from ten- to 12-fold for oxyfluorfen and glufosinate respectively. Similarly, about 14-fold resistance to both oxyfluorfen and glufosinate was estimated on average for the three Lolium species when growth reduction (GR 50 ) was assessed. This study identified oxyfluorfen resistance in a grass species for the first time. A major threat to sustainability of perennial crops in the Iberian Peninsula is evident, as multiple resistance to non-selective glyphosate, glufosinate and oxyfluorfen herbicides has evolved in L. rigidum, L. perenne and L. multiflorum weeds. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. Efficacy evaluation of selected herbicides on weed control and productivity evaluation of Bt cotton in Punjab.

    Science.gov (United States)

    Singh, Kulvir; Rathore, Pankaj

    2015-07-01

    Field experiments were conducted during Kharif 2012 and 2013 to evaluate the efficacy of different herbicides for weed management in cotton. Highest seed cotton yield (3537.3 kg ha(-1)) was recorded in weed free plots followed by pendimethalin @1.0 kg a.i ha(-1) as Pre.em.+quizalofopethyl @50 g a.i ha(-1) post-em at 2-4 weed leaf stage + one hoeing (3318.9 kg ha") owing to improved number of bolls per plant and boll weight. Statistically least yield was recorded underweedy check (1435.4 kg ha(-1)). Application of pyrithiobac sodium could not express any visible toxic effect on crop indicating its selectivity for cotton, although none of the tested new chemicals i.e., pyrithiobac sodium@ 62.5g a.i ha(-1) and quizalofopethyl @50g a.i ha(-1) when applied alone could not outperform the existing recommended chemicals for weed management. Yield losses to the extent of 6.2-59.4% were recorded due to weed competition. Weed control efficiency (WCE) was highest under weed free check (86.8%) followed by pendimethalin @1.0 kg a.i ha(-1) as Pre. em.+quizalofopethyl @50g a.i ha(-1), at 2-4 weed leaf stage + one hoeing (73.7%), whereas minimum values were for weedy check (24.7%). Though net returns (r94660 ha(-1)) were highest for weed free check but higher B:C ratio (2:11) was observed for pendimethalin @1.0 kg a.i ha(-1) as Pre em.+quizalofopethyl @50 g a.i ha(-1) post-em at 2-4 weed leaf stage+one hoeing. Therefore, for reasons such as labor shortage besides their timely availability, using these herbicides in combination with cultural practices could be the practical solution foreconomically efficient and effective weed management.

  7. Screening and selection of most potent diazotrophic cyanobacterial isolate exhibiting natural tolerance to rice field herbicides for exploitation as biofertilizer.

    Science.gov (United States)

    Singh, Surendra; Datta, Pallavi

    2006-01-01

    Periodic applications of heavy dosages of herbicides in modern rice-agriculture are a necessary evil for obtaining high crop productivity. Such herbicides are not only detrimental to weeds but biofertilizer strains of diazotrophic cyanobacteria also. It is therefore, essential to screen and select such biofertilizer strains of diazotrophic cyanobacteria exhibiting natural tolerance to common rice-field herbicides that can be further improved by mutational techniques to make biofertilizer technology a viable one. Therefore, efforts have been made to screen five dominant diazotrophic cyanobacterial forms e.g. filamentous heterocystous Nostoc punctiforme , Nostoc calcicola , Anabaena variabilis and unicellular Gloeocapsa sp. and Aphanocapsa sp. along with standard laboratory strain Nostoc muscorum ISU against increasing concentrations (0-100 mg l(-1) of four commercial grade common rice-field herbicides i.e. Arozin, Butachlor, Alachlor and 2,4-D under diazotrophic growth conditions. The lethal and IGC(50) concentrations for all four herbicides tested were found highest for A. variabilis as compared to other test cyanobacteria. The lowest reduction in chlorophyll a content, photosynthetic oxygen evolution, and N(2)-fixation was found in A. variabilis as compared to other rice field isolates and standard laboratory strain N. muscorum ISU. On the basis of prolong survival potential and lowest reductions in vital metabolic activities tested at IGC(50) concentration of four herbicides, it is concluded that A. variabilis is the most potent and promising cyanobacterial isolate as compared with other forms. This could be further improved by mutational techniques for exploitation as most potential and viable biofertilizer strain.

  8. Dicotyledon Weed Quantification Algorithm for Selective Herbicide Application in Maize Crops

    DEFF Research Database (Denmark)

    Laursen, Morten Stigaard; Nyholm Jørgensen, Rasmus; Midtiby, Henrik Skov

    2016-01-01

    The stricter legislation within the European Union for the regulation of herbicides that are prone to leaching causes a greater economic burden on the agricultural industry through taxation. Owing to the increased economic burden, research in reducing herbicide usage has been prompted. High-resol...

  9. Using GLEAMS to Select Environmental Windows for Herbicide Application in Forests

    Science.gov (United States)

    M.C. Smith; J.L. Michael; W.G. Koisel; D.G. Nealy

    1994-01-01

    Observed herbicide runoff and groundwater data from a pine-release herbicide application study near Gainesville, Florida were used to validate the GLEAMS model hydrology and pesticide component for forest application. The study revealed that model simulations agreed relatively well with the field data for the one-year study. Following validation, a modified version of...

  10. Herbicide toxicity, selectivity and hormesis of nicosulfuron on 10 Trichogrammatidae (Hymenoptera) species parasitizing Anagasta ( = Ephestia) kuehniella (Lepidoptera: Pyralidae) eggs.

    Science.gov (United States)

    Leite, Germano L D; de Paulo, Paula D; Zanuncio, José C; Tavares, Wagner De S; Alvarenga, Anarelly C; Dourado, Luan R; Bispo, Edilson P R; Soares, Marcus A

    2017-01-02

    Selective agrochemicals including herbicides that do not affect non-target organisms such as natural enemies are important in the integrated pest management (IPM) programs. The aim of this study was to evaluate the herbicide toxicity, selectivity and hormesis of nicosulfuron, recommended for the corn Zea mays L. (Poaceae) crop, on 10 Trichogrammatidae (Hymenoptera) species. A female of each Trichogramma spp. or Trichogrammatoidea annulata De Santis, 1972 was individually placed in plastic test tubes (no choice) with a cardboard containing 45 flour moth Anagasta ( = Ephestia) kuehniella Zeller, 1879 (Lepidoptera: Pyralidae) eggs. Parasitism by these natural enemies was allowed for 48 h and the cardboards were sprayed with the herbicide nicosulfuron at 1.50 L.ha -1 , along with the control (only distilled water). Nicosulfuron reduced the emergence rate of Trichogramma bruni Nagaraja, 1983 females, but increased that of Trichogramma pretiosum Riley, 1879, Trichogramma acacioi Brun, Moraes and Smith, 1984 and T. annulata females. Conversely, this herbicide increased the emergence rate of Trichogramma brasiliensis Ashmead, 1904, T. bruni, Trichogramma galloi Zucchi, 1988 and Trichogramma soaresi Nagaraja, 1983 males and decreased those of T. acacioi, Trichogramma atopovilia Oatman and Platner, 1983 and T. pretiosum males. In addition, nicosulfuron reduced the sex ratio of T. galloi, Trichogramma bennetti Nagaraja and Nagarkatti, 1973 and T. pretiosum and increased that of T. acacioi, T. bruni, T. annulata, Trichogramma demoraesi Nagaraja, 1983, T. soaresi and T. brasiliensis. The herbicide nicosulfuron was "harmless" (class 1, <30% reduction) for females and the sex ratio of all Trichogrammatidae species based on the International Organization for Biological Control (IOBC) classification. The possible hormesis effect of nicosulfuron on Trichogrammatidae species and on the bacterium Wolbachia sp. (Rickettsiales: Rickettsiaceae) was also discussed.

  11. Selection of relatively exact reference genes for gene expression studies in goosegrass (Eleusine indica) under herbicide stress.

    Science.gov (United States)

    Chen, Jingchao; Huang, Zhaofeng; Huang, Hongjuan; Wei, Shouhui; Liu, Yan; Jiang, Cuilan; Zhang, Jie; Zhang, Chaoxian

    2017-04-21

    Goosegrass (Eleusine indica) is one of the most serious annual grassy weeds worldwide, and its evolved herbicide-resistant populations are more difficult to control. Quantitative real-time PCR (qPCR) is a common technique for investigating the resistance mechanism; however, there is as yet no report on the systematic selection of stable reference genes for goosegrass. This study proposed to test the expression stability of 9 candidate reference genes in goosegrass in different tissues and developmental stages and under stress from three types of herbicide. The results show that for different developmental stages and organs (control), eukaryotic initiation factor 4 A (eIF-4) is the most stable reference gene. Chloroplast acetolactate synthase (ALS) is the most stable reference gene under glyphosate stress. Under glufosinate stress, eIF-4 is the best reference gene. Ubiquitin-conjugating enzyme (UCE) is the most stable reference gene under quizalofop-p-ethyl stress. The gene eIF-4 is the recommended reference gene for goosegrass under the stress of all three herbicides. Moreover, pairwise analysis showed that seven reference genes were sufficient to normalize the gene expression data under three herbicides treatment. This study provides a list of reliable reference genes for transcript normalization in goosegrass, which will facilitate resistance mechanism studies in this weed species.

  12. Seletividade de herbicidas sobre Myracrodruon urundeuva (Aroeira Selectivity of herbicides upon Myracrodruon urundeuva (Aroeira

    Directory of Open Access Journals (Sweden)

    N.F. Duarte

    2006-06-01

    Full Text Available O objetivo deste trabalho foi verificar a seletividade de herbicidas utilizados em áreas de eucalipto sobreo crescimento de Myracrodruon urundeuva. O experimento foi conduzido em casa de vegetação em duas épocas diferentes (2002 e 2003, em delineamento inteiramente casualizado, arranjado em esquema fatorial (5x4, sendo cinco herbicidas em quatro doses, com seis repetições. Os tratamentos, com as doses, foram: haloxyfop-methyl (0,00, 120, 240 e 480 g ha-1, sulfentrazone (0,00, 300, 600 e 1.200 g ha-1, isoxaflutole (0,00, 150, 300 e 600 g ha-1, oxyfluorfen (0,00, 720, 1.440 e 2.880 g ha-1; e glyphosate (0,00, 720, 1.440 e 2.880 g ha-1. Em ambos os experimentos foram avaliados: efeitos fitotóxicos do produto, número de folíolos, altura de plantas; no segundo, foi feita ainda a análise de clorofila a e b e de carotenóides. O herbicida que apresentou maior fitoxicidade e que comprometeu o desenvolvimento da aroeira foi o glyphosate, sendo, portanto, não recomendado para o controle de invasoras em áreas de plantio de aroeira. Os outros herbicidas não comprometeram o desenvolvimento desta planta, apresentando, por isso, potencial para uso no manejo de plantas daninhas no cultivo desta espécie.The objective of this work was to verify the selectivity of herbicides applied in eucalyptus areas upon the growth of Myracrodruon urundeuva.. The experiment was carried out under greenhouse conditions during two seasons (2002 and 2003, in a completely randomized experimental design with five herbicides in four doses arranged in a factorial design 5x4, and six replicates. The treatments were: haloxyfop-methyl at the doses (0.00, 120, 240 and 480 g ha-1; sulfentrazone (0.00, 300, 600 and 1.200 g ha-1, isoxaflutole (0.00, 150, 300 and 600 g ha-1; oxyfluoren (0.00, 720, 1.440 and 2.880 g ha-1 and glyphosate (0.00, 720, 1.440 and 2.880 g ha-1 plant toxicity effects, number of leaflets and plant height were evaluated in both experiments and analyses of

  13. Auxin molecular field maps define AUX1 selectivity: many auxin herbicides are not substrates

    Czech Academy of Sciences Publication Activity Database

    Hoyerová, Klára; Hošek, Petr; Quareshy, M.; Li, J.; Klíma, Petr; Kubeš, Martin; Yemm, A. A.; Neve, P.; Tripathi, A.; Bennett, M.J.; Napier, R. M.

    2018-01-01

    Roč. 217, č. 4 (2018), s. 1625-1639 ISSN 0028-646X R&D Projects: GA ČR(CZ) GA16-19557S; GA MŠk LD15137 Grant - others:OPPK(XE) CZ.2.16/3.1.00/21519 Institutional support: RVO:61389030 Keywords : auxin transport * cheminformatics * herbicide * herbicide resistance * molecular field maps * pharmacophore * structure–activity relationship * uptake carrier Subject RIV: ED - Physiology OBOR OECD: Cell biology Impact factor: 7.330, year: 2016

  14. Effects of a phosphinothricin based herbicide on selected groups of soil microorganisms.

    Science.gov (United States)

    Pampulha, M E; Ferreira, M A S S; Oliveira, A

    2007-08-01

    The effects of the herbicide glufosinate-ammonium on soil microbial populations and activity were observed in a laboratory microcosms over a 40 day period. Culturable aerobic bacteria, fungi and actinomycetes, the fundamental groups of heterotrophic microorganisms, were studied. Nitrifiers, considered a very sensitive group to these compounds were also evaluated. Since herbicides have been found to inhibit decomposition of cellulose in the soil, the effects of glufosinate on cellulolytic bacteria and fungi were determined. Dehydrogenase activity as a measure of microbial activity was another parameter considered. Both stimulating and inhibitory effects on microbial populations were observed, depending on concentration of the herbicide and the period of incubation. A severe inhibiting effect of glufosinate on dehydrogenase activity was found. We concluded that the widespread use of this herbicide may have possible injurious effects on soil microorganisms and their activities. The toxicity exerted by glufosinate may lead to a shift in microbial community structure tending toward a significant loss in functional diversity. Dehydrogenase activity was shown to be an important indicator of glufosinate side-effects.

  15. Dicotyledon Weed Quantification Algorithm for Selective Herbicide Application in Maize Crops.

    Science.gov (United States)

    Laursen, Morten Stigaard; Jørgensen, Rasmus Nyholm; Midtiby, Henrik Skov; Jensen, Kjeld; Christiansen, Martin Peter; Giselsson, Thomas Mosgaard; Mortensen, Anders Krogh; Jensen, Peter Kryger

    2016-11-04

    The stricter legislation within the European Union for the regulation of herbicides that are prone to leaching causes a greater economic burden on the agricultural industry through taxation. Owing to the increased economic burden, research in reducing herbicide usage has been prompted. High-resolution images from digital cameras support the studying of plant characteristics. These images can also be utilized to analyze shape and texture characteristics for weed identification. Instead of detecting weed patches, weed density can be estimated at a sub-patch level, through which even the identification of a single plant is possible. The aim of this study is to adapt the monocot and dicot coverage ratio vision (MoDiCoVi) algorithm to estimate dicotyledon leaf cover, perform grid spraying in real time, and present initial results in terms of potential herbicide savings in maize. The authors designed and executed an automated, large-scale field trial supported by the Armadillo autonomous tool carrier robot. The field trial consisted of 299 maize plots. Half of the plots (parcels) were planned with additional seeded weeds; the other half were planned with naturally occurring weeds. The in-situ evaluation showed that, compared to conventional broadcast spraying, the proposed method can reduce herbicide usage by 65% without measurable loss in biological effect.

  16. The influence of selected spraying parameters on two formulation of sulfonylurea herbicides effect

    Directory of Open Access Journals (Sweden)

    Renata KIELOCH

    2013-03-01

    Full Text Available The objective of this study was the evaluation of spray volume and nozzle type effect on different formulation (water dispersible granules - WG and oil dispersion - OD of two sulfonylurea herbicides: the mixture iodosulfuron methyl sodium + amidosulfuron and iodosulfuron methyl sodium + mesosulfuron methyl efficacy. There were investigated three levels of spray volume (125 l*ha-1, 250 l*ha-1 and 350 l*ha-1 and two types of nozzle (extended range flat nozzle TeeJet XR 11003-VS and drift guard flat nozzle TeeJet DG 11003-VS. Each herbicide was used at recommended dose and reduced by half. Spray volume and nozzle type did not affect activity of the mixture iodosulfuron methyl sodium + amidosulfuron, but differentiated the efficacy of OD formulation of iodosulfuron methyl sodium + mesosulfuron methyl, when it was applied at lowered dose. As spray volume rose, herbicide efficacy decreased. Nozzle type influenced OD formulation of the mixture iodosulfuron methyl sodium + mesosulfuron methyl, independently on dose. Significantly weaker efficacy was obtained when drift guard nozzle was used.

  17. Selectivity and stability of new herbicides and herbicide combinations for the seed yields of some field crops II. Effect at milk thistle (Silybum Marianum Gaertn.)

    OpenAIRE

    G. Delchev

    2016-01-01

    Abstract. During 2013 – 2015 on pellic vertisol soil type was conducted a field experiment. Under investigation was Bulgarian milk thistle cultivar Silmar (Silybum marianum Gaertn.). Factor A included the years of investigation. Factor B included no treated check, 6 soil-applied herbicides – Tendar EC, Sharpen 33 EC, Merlin flex 480 SC, Smerch 24 ЕC, Raft 400 SC, Eagle 75 DF and 5 foliar-applied herbicides – Kalin flo, Eclipse 70 DWG, Sultan 500 SC, Granstar super 50 SG, Starane 250 ...

  18. Photocatalytic degradation of selected herbicides in aqueous suspensions of doped titania under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sojic, Daniela V., E-mail: daniela.sojic@dh.uns.ac.rs [Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg D. Obradovica 3, 21000 Novi Sad (Serbia); Despotovic, Vesna N., E-mail: vesna.despotovic@dh.uns.ac.rs [Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg D. Obradovica 3, 21000 Novi Sad (Serbia); Abazovic, Nadica D., E-mail: kiki@vinca.rs [Vinca Institute of Nuclear Sciences, 11001 Beograd, PO Box 522 (Serbia); Comor, Mirjana I., E-mail: mirjanac@vinca.rs [Vinca Institute of Nuclear Sciences, 11001 Beograd, PO Box 522 (Serbia); Abramovic, Biljana F., E-mail: biljana.abramovic@dh.uns.ac.rs [Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg D. Obradovica 3, 21000 Novi Sad (Serbia)

    2010-07-15

    The aim of this work was to study the efficiency of Fe- and N-doped titania suspensions in the photocatalytic degradation of the herbicides RS-2-(4-chloro-o-tolyloxy)propionic acid (mecoprop, MCPP), (4-chloro-2-methylphenoxy)acetic acid (MCPA), and 3,6-dichloropyridine-2-carboxylic acid (clopyralid, CP) under the visible light ({lambda} {>=} 400 nm) irradiation. The obtained results were compared with those of the corresponding undoped TiO{sub 2} (rutile/anatase) and of the most frequently used TiO{sub 2} Degussa P25. Computational modeling procedures were used to optimize geometry and molecular electrostatic potentials of MCPP, MCPA and CP and discuss the obtained results. The results indicate that the efficiency of photocatalytic degradation is greatly influenced by the molecular structure of the compound. Lowering of the band gap of titanium dioxide by doping is not always favorable for increasing photocatalytic efficiency of degradation.

  19. Plant breeding by using radiation mutation - Selection of herbicide-resistant cell lines by using {gamma}-rays

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyo Yeon [Sunchun University, Sunchun (Korea); Seo, Yong Weon [Korea University, Seoul (Korea)

    2000-04-01

    In order to develop the herbicide resistant cell lines, micro calli derived from rice anther culture and mature seed of wheat cultivars were irradiated with gamma rays. 1) The callus was dedifferentiated by 7 or 21 day pretreatment at 7 deg. C in two rice cultivars, Ilpumbyeo ad Dongjinbyeo. 2) To check the optimum concentration of herbicide, three herbicides were tested with micro calli. 3) The optimum dose of gamma ray to seeds of wheat seemed to be from 100 to 150 Gy. 4) AFLP and RAPD technique were established to develope herbicide resistant molecular marker in rice. 34 refs., 10 figs., 5 tabs. (Author)

  20. Avaliação de herbicidas para dois cultivares de mandioca Selectivity of herbicide alternatives for two cassava cultivars

    Directory of Open Access Journals (Sweden)

    D.F Biffe

    2010-12-01

    Full Text Available É importante avaliar a tolerância de variedade de mandioca a novas alternativas de controle químico, com o intuito de ampliar as opções disponíveis. Este trabalho teve como objetivo avaliar a seletividade de herbicidas aplicados em pré-emergência, para duas importantes variedades de mandioca cultivadas no Estado do Paraná. Os herbicidas e respectivas doses (g i.a. ha-1 avaliadas foram: diuron (400 e 800, metribuzin (360 e 720, isoxaflutole (60, atrazine (720, S-metolachlor (1.920 e as misturas ametryn + clomazone (1.350+1.900, ametryn+trifluralin (1.500+1.350, isoxaflutole+metribuzin (60+320, isoxaflutole+diuron (60+400, combinados com uso de uma testemunha dupla adjacente a cada tratamento. Os cultivares utilizados neste trabalho foram Fécula Branca e Fibra. Apenas o herbicida S-metolachlor, para ambos os cultivares, e metribuzin (360 g i.a. ha-1, para o cultivar Fibra, não provocaram injúrias. Atrazine provocou redução de estande para o cultivar Fécula Branca aos 60 DAP, mas não foi detectada redução na altura de plantas. Tanto atrazine (para os dois cultivares quanto diuron na dose de 800 g i.a. ha-1 (para o cultivar Fécula Branca afetaram a produtividade de raízes. Dessa forma, atrazine foi considerado não seletivo para ambos os cultivares, e a maior dose de diuron foi também considerada não seletiva para o cultivar Fécula Branca. Há diferenças de tolerância entre os cultivares, sendo o Fibra, de modo geral, mais tolerante aos herbicidas avaliados.It is important to evaluate the tolerance of cassava varieties under new weed chemical control alternatives. Thus, this study aimed to evaluate the selectivity of herbicides, applied at pre-emergence, for two important cassava varieties grown in the state of Paraná, Brazil. The herbicides and respective doses (g a.i. ha-1 were: diuron (400 and 800, metribuzin (360 and 720, isoxaflutole (60, atrazine (720, S-metolachlor (1,920 and mixtures ametryn+clomazone (1

  1. Seletividade de herbicidas aplicados nas gramas Santo Agostinho e Esmeralda Selectivity of herbicides applied on St. Augustinegrass and Emerald turfs

    Directory of Open Access Journals (Sweden)

    N.V. Costa

    2010-01-01

    Full Text Available Objetivou-se neste trabalho avaliar a seletividade de herbicidas aplicados nas gramas Santo Agostinho (Stenotaphrum secundatum e Esmeralda (Zoysia japonica em condições de campo. O delineamento experimental utilizado foi o de blocos casualizados, com quatro repetições. As gramas foram cortadas a 3 cm de altura e, em seguida, foram feitas as aplicações dos herbicidas. Os tratamentos utilizados foram: testemunha sem aplicação, fluazifop-p-butil (125 g ha-1, sethoxydim+óleo mineral (276 g ha-1 + 0,5% v v-1 de Assist, bispyribac-sodium (25 g ha-1, chlorimuron-ethyl (15 g ha-1, ethoxysulfuron (150 g ha-1, halosulfuron (112,5 g ha-1, iodosulfuron-methyl (10 g ha-1, metsulfuron-methyl (2,4 g ha-1, nicosulfuron (125 g ha-1, pyrithiobac-sodium (140 g ha-1, trifloxysulfuron-sodium (22,5 g ha-1, 2,4-D (720 g ha-1, quinclorac (375 g ha-1, atrazina (1.250 g ha-1, bentazon (600 g ha-1, linuron (1.350 g ha-1, fomesafen (187,5 g ha-1, lactofen (120 g ha-1, oxadiazon (600 g ha-1 e oxyfluorfen (720 g ha-1. Os herbicidas que apresentaram potencial de seletividade para o gramado de S. secundatum foram: os inibidores da ALS chlorimuron-ethyl, ethoxysulfuron, halosulfuron, iodosulfuron-methyl e metsulfuron-methyl, o mimetizador de auxina 2,4-D, os inibidores do fotossistema II atrazina e bentazon, bem como os inibidores da Protox fomesafen, lactofen e o oxadiazon. Para o gramado de Z. japonica, os herbicidas que apresentaram potencial de seletividade foram: os inibidores da ALS chlorimuron-ethyl, ethoxysulfuron, halosulfuron, metsulfuron-methyl e nicosulfuron, os mimetizadores de auxina 2,4-D e quinclorac, os inibidores do fotossistema II atrazina e bentazon, além dos inibidores da Protox fomesafen, lactofen e o oxadiazon.The objective of this study was to evaluate the selectivity of herbicides applied on turfgrasses St. Augustinegrass (Stenotaphrum secundatum and Emerald (Zoysia japonica under field conditions. The experimental design was randomized blocks

  2. Effects of selected low-impact-development (LID) techniques on water quality and quantity in the Ipswich River Basin, Massachusetts-Field and modeling studies

    Science.gov (United States)

    Zimmerman, Marc J.; Barbaro, Jeffrey R.; Sorenson, Jason R.; Waldron, Marcus C.

    2010-01-01

    During the months of August and September, flows in the Ipswich River, Massachusetts, dramatically decrease largely due to groundwater withdrawals needed to meet increased residential and commercial water demands. In the summer, rates of groundwater recharge are lower than during the rest of the year, and water demands are higher. From 2005 to 2008, the U.S. Geological Survey, in a cooperative funding agreement with the Massachusetts Department of Conservation and Recreation, monitored small-scale installations of low-impact-development (LID) enhancements designed to diminish the effects of storm runoff on the quantity and quality of surface water and groundwater. Funding for the studies also was contributed by the U.S. Environmental Protection Agency's Targeted Watersheds Grant Program through a financial assistance agreement with Massachusetts Department of Conservation and Recreation. The monitoring studies examined the effects of (1) replacing an impervious parking lot surface with a porous surface on groundwater quality, (2) installing rain gardens and porous pavement in a neighborhood of 3 acres on the quantity and quality of stormwater runoff, and (3) installing a 3,000-square foot (ft2) green roof on the quantity and quality of stormwater runoff. In addition, the effects of broad-scale implementation of LID techniques, reduced water withdrawals, and water-conservation measures on streamflow in large areas of the basin were simulated using the U.S. Geological Survey's Ipswich River Basin model. From June 2005 to 2007, groundwater quality was monitored at the Silver Lake town beach parking lot in Wilmington, MA, prior to and following the replacement of the conventional, impervious-asphalt surface with a porous surface consisting primarily of porous asphalt and porous pavers. Changes in the concentrations of the water-quality constituents, phosphorus, nitrogen, cadmium, chromium, copper, lead, nickel, zinc, and total petroleum hydrocarbons, were monitored

  3. Effect of selectivity of herbicides and plant growth regulators used in sugarcane crops on immature stages of Trichogramma galloi (Hymenoptera: Trichogrammatidae).

    OpenAIRE

    OLIVEIRA, H. N. de; ANTIGO, M. R.; CARVALHO, G. A.; GLAESER, D. F.

    2014-01-01

    Herbicides and plant growth regulators are often used in sugarcane management. However, the use of non-selective pesticides can cause adverse effects on the efficiency of beneficial insects in integrated pest management. Within this context, this study aimed to evaluate the effect of such products on the immature stages of the parasitoid Trichogramma galloi. Eggs of Diatraea saccharalis containing the parasitoid at the egg-larva stage and at the prepupal and pupal stages were immersed in test...

  4. Effect of selectivity of herbicides and plant growth regulators used in sugarcane crops on immature stages of Trichogramma galloi (Hymenoptera: Trichogrammatidae)

    OpenAIRE

    Oliveira, H.N.; Antigo, M.R.; Carvalho, G.A.; Glaeser, D.F.

    2014-01-01

    Herbicides and plant growth regulators are often used in sugarcane management. However, the use of non-selective pesticides can cause adverse effects on the efficiency of beneficial insects in integrated pest management. Within this context, this study aimed to evaluate the effect of such products on the immature stages of the parasitoid Trichogramma galloi. Eggs of Diatraea saccharalis containing the parasitoid at the egg-larva stage and at the prepupal and pupal stages were immersed in test...

  5. Herbicidas no transplante de mudas de sisal (Agave sisalana perr. Weed control and herbicide selectivity to sisal (Agave sisalana perr.

    Directory of Open Access Journals (Sweden)

    Antonio Luiz de Barros Salgado

    1980-01-01

    Full Text Available Com o objetivo de verificar a eficiência de hebraicas no controle de plantas daninhas e sua seletividade à cultura do sisal, foi instalado, em setembro de 1976, um experimento de campo em solo argiloso, com os seguintes tratamentos (i.a./hectare trifluralin a 0,84 e 0,96kg em pré-plantio com incorporação; alachlor a 2,40 e 3,26kg; metribuzin a 0,70 e 0,84kg; bromacil a 1,60 e 2,40kg; terbacil a 1,60 e 2,40kg; diuron a 2,40 e 3,20kg; simazine a 3,20 e 4,00kg; fluometuron a 1,20 e 1,60kg, todos em pré-emergência; uma testemunha carpida e outra sem capina. Foram feitas avaliações de controle do mato aos 67 e 114 dias e da condição da cultura aos 600 dias após a aplicação. Aos 114 dias, o controle de gramíneas foi acima de 90% pelo trifluralin, bromacil e terbacil, em torno de 80% pelo simazine, e inferior a 75% pelos demais; para dícotiledôneas, o controle foi de 90 a 100% pelo bromacil e terbacil, e de 80 a 85%o pelo simazine. Nenhum dos tratamentos afetou a cultura durante o período considerado, que foi de 600 dias. Aos 550 dias, fez-se avaliação da área coberta por reinfestação do mato, tendo o terbacil controlado ainda 75 e 95% do total, respectivamente, para as doses menor e maior; o trifluralin, 60 e 70% e, os demais, abaixo de 45%. Na avaliação final da cultura, aos 600 dias, foram considerados: população de plantas, número de plantas com perfilhos e condição da cultura. Os tratamentos que realizaram melhor controle do mato apresentaram também os melhores índices de desenvolvimento da cultura, atestando sua seletividade.The weed control with herbicides and its selectivity to sisal were studied on a clay soil field trial. The treatments (in a.i./ha were: 0.84 and 0.96kg of pre-plant incorporated trifluralin; 2.40 and 3.26kg of alachlor; 0.70 and 0.84kg of metribuzin; 1.60 and 2.40kg of bromacil; 1.60 and 2.40kg of terbacil; 2.40 and 3.20k- of diuron; 3.20 and 4.00kg of simazine; 1.20 and 1.60kg of fluometuron

  6. Seletividade de herbicidas aplicados em pré-emergência em gramíneas forrageiras Selectivity of pre-emergence herbicides applied on forage grasses

    Directory of Open Access Journals (Sweden)

    A.C.P Rodrigues-Costa

    2011-09-01

    Full Text Available O presente trabalho teve o objetivo de avaliar a seletividade de herbicidas aplicados em pré-emergência sobre a produção e a qualidade de sementes de Brachiaria brizantha cv. Marandu e Brachiaria decumbens cv. Basilisk. Os herbicidas avaliados foram: diuron (800 e 1.600 g ha-1, ametryn (625 e 1.250 g ha-1, imazaquin (75 e 150 g ha-1, imazethapyr (50 e 100 g ha-1 e flumetsulam (70 e 140 g ha-1, além de uma testemunha sem aplicação de herbicidas. As espécies foram avaliadas separadamente no campo. Os experimentos foram instalados no delineamento em blocos casualizados com quatro repetições. Os herbicidas ametryn (625 g ha-1, imazaquin (75 e 150 g ha-1, imazethapyr (50 e 100 g ha-1 e flumetsulam (70 e 140 g ha-1 foram os que proporcionaram maior seletividade às plantas de B. brizantha, enquanto para B. decumbens o diuron (800 e 1.600 g ha-1, o ametryn (625 e 1.250 g ha-1 e o imazethapyr (50 e 100 g ha-1 foram mais seletivos, destacando-se o diuron na menor dose. Contudo, os herbicidas avaliados não alteram a produção e a qualidade das sementes das forrageiras estudadas.This study aimed to evaluate the selectivity of pre-emergence herbicides on yield and seed quality of Brachiaria brizantha cv. Brizantha and Brachiaria decumbens cv. Basilisk. The herbicides evaluated were: diuron (800 and 1.600 g ha-1, ametryn (625 and 1.250 g ha-1, imazaquin (75 and 150 g ha-1, imazethapyr (50 and 100 g ha-1 and flumetsulam (70 and 140 g ha-1, plus a control without herbicide application. The species were evaluated separately in the field. The experiments were arranged in a randomized block design with four replications. The herbicides ametryn (625 g ha-1, imazaquin (75 and 150 g ha-1, imazethapyr (50 and 100 g ha-1, and flumetsulam (70 and 140 g ha-1 provided the highest selectivity to B. brizantha plants, while for B. decumbens, diuron (800 and 1.600 g ha-1, ametryn (625 and 1.250 g ha-1, and imazethapyr (50 and 100 g ha-1 were more selective

  7. Seletividade do herbicida fluazifop-p-butil para cucurbitáceas Selectivity of the herbicide fluazifop-p-buthyl for cucurbitaceae

    Directory of Open Access Journals (Sweden)

    R.A. Vidal

    2000-01-01

    Full Text Available Experimentos foram conduzidos em condições de casa de vegetação, com o objetivo de avaliar a seletividade do herbicida fluazifop-p-butil nas doses de 0, 94, 188, 376 e 752 g i.a. ha-1 para cinco espécies de cucurbitáceas (abobrinha, melancia, melão, moranga e pepino. Foi determinada a fitotoxicidade aos 14 dias após a aplicação dos tratamentos (DAT. Aos 20 DAT foram avaliadas a estatura, área foliar e matéria seca. O melão e o pepino mostraram sensibilidade ao fluazifop-p-butil na maior dose estudada, com maior intensidade no melão. Os resultados demonstraram que existe resposta a estes herbicidas mesmo dentro da classe Dicotiledoneae. Especula-se que essas respostas possam auxiliar no entendimento do completo mecanismo de ação desse herbicida.Experiments were conducted under greenhouse conditions to evaluate the selectivity of the herbicide fluazifop-p-buthyl at rates of 0, 94, 188 and 752 g a.i. ha-1 for five cucurbitaceous species (summer squash, watermelon, melon, pumpkin and cucumber. Plant injury at 14 days after treatments (DAT and plant size, leaf area and dry weight at 20 DAT were determined. Melon and cucumber were susceptible to fluazifop-p-buthyl at the highest rate with highest herbicide effect being observed on melon. These results indicated that responses to these herbicides occur, even in the Dicotiledonae class. These responses are thought to help understand the overall mechanism of action of this herbicide.

  8. Seletividade de herbicidas pós-emergentes na cultura da mandioca Selectivity of post-emergent herbicides for cassava crop

    Directory of Open Access Journals (Sweden)

    D.V. Silva

    2012-12-01

    Full Text Available A resposta da mandioca à aplicação de herbicidas varia desde a total seletividade até o completo comprometimento da produção devido à intoxicação provocada. Desse modo, objetivou-se neste trabalho avaliar a seletividade de herbicidas aplicados em pós-emergência na mandioca. Para isso, foi conduzido experimento em casa de vegetação, em blocos casualizados com 23 tratamentos (22 herbicidas + testemunha, em quatro repetições. Os herbicidas foram aplicados 60 dias após a brotação da mandioca, quando as plantas apresentavam cerca de 15 folhas completamente expandidas. Avaliou-se semanalmente a toxicidade das plantas e, aos 35 dias após a aplicação, elas foram coletadas para determinação da matéria seca. Os sintomas mais visíveis de intoxicação da mandioca ocorreram 21 dias depois da aplicação, para a maioria dos produtos testados. Ao final do período de avaliação, a mandioca apresentava sinais de recuperação dos danos visuais provocados pelos herbicidas tóxicos à cultura. Ametryn, ametryn + trifloxysulfuron-sodium, atrazine, diuron + hexazinone e sulfentrazone provocaram as maiores reduções de matéria seca e causaram os maiores danos visíveis; de modo contrário, bentazon, fluazifop-p-butil, mesotrione e tembotrione foram os menos tóxicos à cultura. Constataram-se diferentes níveis de seletividade dos herbicidas à cultura, sendo bentazon, fluazifop-p-butil, mesotrione e tembotrione os herbicidas considerados seletivos para uso em programas de manejo de plantas daninhas.The cassava response to herbicide application varies from complete selectivity to full production loss due to the poisoning caused. Thus, the objective of this work was to evaluate the selectivity of herbicides applied at post-emergence in cassava. An experiment was arranged in a randomized block design, under greenhouse conditions, including 23 treatments (22 herbicides + control and four replications. The herbicides were applied 60 days

  9. Assessment of the levels of N- (Phosphonomethyl) glycine glyphosate in selected glyphosate-based herbicides on the Ghanaian market

    International Nuclear Information System (INIS)

    Iddrisu, Adisatu

    2016-07-01

    Sixty one (61) samples of Glyphosate based herbicides were collected from the central commercial hub of Kumasi (Kejetia) and ware houses of importers in Ashanti and Greater Accra regions of Ghana and analyzed using high performance liquid chromatography (HPLC). Information about the efficacy of the numerous Glyphosate herbicides on the market was also collected by way of questionnaire. Results of the analysis indicated that only ten (16.4 %) out of the sixty one samples met the Environmental Protection Agency’s requirement of ±5 % of the stated active ingredient concentration and 51 samples representing 83.6 % were all out of the acceptable range. Active ingredient was either understated or overstated. About 21.6 % of the samples that failed to meet requirements were overstated and 78.4 % were understated. Apart from a few of the samples that had concentrations higher than stated label claims with 69 g/L (19.2 %) highest, most samples were generally lower than stated label claims. Some (G09, G18 and G44) samples contained virtually no active ingredient with shortfalls as high as 98.6%. Some of these shortfalls explained findings from the field investigations where some respondents complained of Glyphosate not being efficacious. Farmers may follow the application and safety instructions but this only holds true as long as the herbicides provide efficient control of weed. This can only be achieved with products of consistently high quality. This study also discovered that, there was no possibility of adulteration of the herbicide along the value chain as results for products picked from ware houses of importers did not differ much from those picked from the open market. Results from the other method employed in Glyphosate determination was UV/VIV spectroscopy, this method is simpler and faster and readily available in most laboratories in Ghana. Results from UV/VIS were comparable to that of the HPLC with generally lower values for UV/VIS readings. It is therefore

  10. Effects of selected herbicides and fungicides on growth, sporulation and conidial germination of entomopathogenic fungus Beauveria bassiana.

    Science.gov (United States)

    Celar, Franci A; Kos, Katarina

    2016-11-01

    The in vitro fungicidal effects of six commonly used fungicides, namely fluazinam, propineb, copper(II) hydroxide, metiram, chlorothalonil and mancozeb, and herbicides, namely isoxaflutole, fluazifop-P-butyl, flurochloridone, foramsulfuron, pendimethalin and prosulfocarb, on mycelial growth, sporulation and conidial germination of entomopathogenic fungus Beauveria bassiana (ATCC 74040) were investigated. Mycelial growth rates and sporulation at 15 and 25 °C were evaluated on PDA plates containing 100, 75, 50, 25, 12.5, 6.25 and 0% of the recommended application rate of each pesticide. The tested pesticides were classified in four scoring categories based on reduction in mycelial growth and sporulation. All pesticides, herbicides and fungicides tested had fungistatic effects of varying intensity, depending on their rate in the medium, on B. bassiana. The most inhibitory herbicides were flurochloridone and prosulfocarb, and fluazinam and copper(II) hydroxide were most inhibitory among the fungicides, while the least inhibitory were isoxaflutole and chlorothalonil. Sporulation and conidial germination of B. bassiana were significantly inhibited by all tested pesticides compared with the control treatment. Flurochloridone, foramsulfuron, prosulfocarb and copper(II) hydroxide inhibited sporulation entirely at 100% rate (99-100% inhibition), and the lowest inhibition was shown by fluazifop-P-butyl (22%) and metiram (33%). At 100% dosage, all herbicides in the test showed a high inhibitory effect on conidial germination. Conidial germination inhibition ranged from 82% with isoxaflutole to 100% with fluorochloridone, pendimethalin and prosulfocarb. At 200% dosage, inhibition rates even increased (96-100%). All 12 pesticides tested had a fungistatic effect on B. bassiana of varying intensity, depending on the pesticide and its concentration. B. bassiana is highly affected by some herbicides and fungicides even at very low rates. Flurochloridone, foramsulfuron

  11. Seletividade de herbicidas aplicados em pós-emergência sobre capim-braquiária Selectivity of post-emergence herbicides applied on signalgrass and palisadegrass

    Directory of Open Access Journals (Sweden)

    Dagoberto Martins

    2007-12-01

    Full Text Available O estudo foi conduzido com o objetivo de avaliar a seletividade de alguns herbicidas inibidores de ALS e FS II aplicados em pós-emergência em plantas de Brachiaria brizantha cv. Marandu e Brachiaria decumbens cv. Basilisk em condições de campo e seu efeito na qualidade das sementes. Os herbicidas testados (em g/ha foram: imazethapyr a 100; chlorimuronethyl a 15; nicosulfuron a 50; bentazon a 720; e atrazine a 3.000, além de uma testemunha, sem aplicação de herbicidas. Dois experimentos em campo foram instalados em delineamento em blocos casualizados com quatro repetições e os ensaios de laboratório em delineamento inteiramente casualizado, com 16 repetições. Todos os herbicidas testados tiveram algum efeito de fitointoxicação visual aos cultivares avaliados. O nicosulfuron foi o herbicida que visualmente proporcionou os níveis mais elevados de injúrias às plantas de B. decumbens e B. brizantha. A produção de MS de B. brizantha nos estádios iniciais de crescimento foi reduzida pelos herbicidas nicosulfuron e atrazine, enquanto, em B. decumbens, apenas o herbicida nicosulfuron ocasionou redução da produção de MS. A qualidade das sementes de ambos os cultivares foi afetada pelo nicosulfuron, que induziu a dormência em sementes de B. decumbens, reduziu a porcentagem de sementes normais e, assim como o atrazine, aumentou a porcentagem de sementes mortas.This work evaluated the herbicides selectivity acetolactate synthase inhibitors and photosynthetic II applied in post- emergency in palisadegrass (Brachiaria brizantha cv. Marandu and signalgrass (Brachiaria decumbens cv. Basilisk plants in field conditions and their effect in seed quality. Treatments tested in g ha-1 were: imazethapyr at 100, chlorimuron-ethyl at 15, nicosulfuron at 50, bentazon at 720, atrazine at 3.000, and control plot. Two field trials were set up on complete randomized block design with four replicates; laboratory studies were carried out in a complete

  12. Biotechnology approaches to developing herbicide tolerance ...

    African Journals Online (AJOL)

    The use of herbicides has revolutionized weed control in many crop production systems. However, with the increasing development of weed resistances to many popular selective herbicides, the need has arisen to rethink the application of chemical weed control. Approaches to maintain the efficiency of chemical weed ...

  13. Seletividade de herbicidas a genótipos de cana-de-açúcar Herbicide selectivity to sugarcane genotypes

    Directory of Open Access Journals (Sweden)

    L Galon

    2009-12-01

    Full Text Available A cultura da cana-de-açúcar, por ter desenvolvimento inicial lento até 60 dias após a emergência, apresenta pouca capacidade competitiva com as plantas daninhas. Por isso, o uso de herbicidas nesse período é prática comum no canavial. No entanto, há variação entre genótipos de cana-de-açúcar na tolerância a herbicidas. Os genótipos pouco tolerantes podem ser intoxicados e, em alguns casos, ocorre redução da produtividade da cana-deaçúcar. Neste trabalho, avaliou-se a tolerância de três genótipos aos herbicidas ametryn, trifloxysulfuron-sodium e à mistura comercial desses, em 0,0, 0,5, 1,0 e 3,0 vezes a dose comercial recomendada. O experimento foi realizado em ambiente protegido. Foi empregado o delineamento experimental inteiramente casualizado, com quatro repetições. Os tratamentos constaram dos genótipos SP80-1816, RB855113 e RB867515, combinados aos herbicidas ametryn, trifloxysulfuron-sodium e ametryn + trifloxysulfuron-sodium, nas doses de 0, 0,5, 1,0 e 3,0 vezes a dose comercial recomendada pelo fabricante. A intoxicação das plantas (% foi avaliada aos 14, 28 e 42 dias após a aplicação dos herbicidas (DAT. As outras variáveis aferidas aos 80 dias após a brotação das gemas foram: área foliar e massa da matéria seca da parte aérea. Em geral, os genótipos SP80-1816 e RB85513 foram menos tolerantes aos herbicidas ametryn, trifloxysulfuron-sodium e à mistura formulada de ametryn + trifloxysulfuron-sodium do que o RB867515 em todas as doses. Eles apresentaram elevados índices de intoxicação aos 14, 28 e 42 dias após a aplicação dos herbicidas. Concluiu-se que o genótipo RB855113 foi o mais sensível aos herbicidas, seguido pelo SP80-1816, sendo o RB867515 o mais tolerante.Due to a slow initial development up to 60 days after emergence, sugarcane shows little competitive capacity over weeds. Thus, the use of herbicides during this period is a common practice in the sugarcane crop. However, there is

  14. Seletividade de herbicidas registrados para a cultura do milho a adultos de Trichogramma pretiosum (Hymenoptera: Trichogrammatidae Selectivity of herbicides registered on corn to Trichogramma pretiosum (Hymenoptera: Trichogrammatidae

    Directory of Open Access Journals (Sweden)

    G.J. Stefanello Júnior

    2008-06-01

    Full Text Available A seletividade de 24 herbicidas registrados para a cultura do milho foi avaliada a Trichogramma pretiosum em condições de laboratório (temperatura de 25±1 ºC, umidade relativa de 70±10%, fotofase de 14 horas e luminosidade de 500 lux. Adultos de T. pretiosum foram colocados em contato com uma película seca dos herbicidas pulverizados sobre placas de vidro e avaliou-se a capacidade de parasitismo das fêmeas. A redução na capacidade de parasitismo dos tratamentos foi comparada com a da testemunha (água destilada e utilizada para classificar os herbicidas em 1, inócuo (99%. Os herbicidas Callisto, Equip Plus, Extrazin SC, Primóleo, Provence 750 WG e Siptran 500 SC são inócuos (classe 1; Agrisato 480 SL, Gesaprim GrDA, Glifos, Glyphosate Nortox, Gliz 480 SL, Polaris, Primatop SC, Sanson 40 SC, Trop e Zapp Qi, levemente nocivos (classe 2; Finale, Herbadox, Poast, Roundup Original, Roundup Transorb e Roundup WG, moderadamente nocivos (classe 3; e Gramoxone 200 e Primestra Gold, nocivos (classe 4 aos adultos de T. pretiosum, nas dosagens utilizadas. Os herbicidas nocivos (classes 2, 3 e 4 deverão passar para as etapas seguintes, que envolverão testes sobre as fases imaturas do parasitóide em condições de laboratório e adultos a campo.The selectivity of 24 herbicides registered on corn to Trichogramma pretiosum (Hymenoptera: Trichogrammatidae was assessed under laboratory conditions (25 ± 1 ºC temperature, 70 ± 10% relative humidity, 14 4 photophase and brightness 500 lux. The adult parasitoids were submitted to a dry film of the herbicides applied on glass plates and the parasitism capacity of the females was evaluated. Reduced parasitism capacity in the treatments was compared with the negative control (distilled water and used to classify the herbicides into four categories: 1, harmless ( 99%. The herbicides Callisto, Equip Plus, Extrazin SC, Primóleo, Provence 750 WG and Siptran 500 SC were found to be harmless (class 1

  15. Seletividade de herbicidas pré-emergentes ao pinhão-manso (Jatropha curcas Selectivity of pre-emergence herbicides to physic nut (Jatropha curcas

    Directory of Open Access Journals (Sweden)

    P.R.R Rocha

    2010-12-01

    Paraguaçu, and factor B by the herbicides (isoxaflutole, oxyfluorfen, sulfentrazone, pendimethalin and tebuthiuron, plus one non-treated control. Intoxication by the herbicides was evaluated at 19, 32, 40, 48, 56 and 64 days after treatments (DAT. Height, leaf area, and plant dry matter were evaluated at 64 DAT. It was verified that the jatropha genotypes have different tolerance to the herbicides studied. Isoxaflutole and tebuthiuron caused severe injuries to all genotypes and negatively affected all the variables evaluated. On the other hand, oxyfluorfen and pendimethalin proved to be selective to the crop and should be evaluated in further studies to be recommended to the crop.

  16. Research methods in weed science: herbicide absorption and translocation in plants using radioisotopes

    Science.gov (United States)

    Herbicide absorption and translocation in plants is a key component in the study of herbicide physiology, mode of action, selectivity, resistance mechanisms, and in the registration process. Radioactive herbicides have been in use for over half-a-century in the research and study of herbicide absorp...

  17. Application of a method based on the measurement of radiation reflectance when estimating the sensitivity of selected grain maize hybrids to the herbicide CALLISTO 480 SC + ATPLUS 463

    Directory of Open Access Journals (Sweden)

    Michal Vondra

    2009-01-01

    Full Text Available The application of methods based on measurements of photosynthesis efficiency is now more and more popular and used not only for the evaluation of the efficiency of herbicides but also for the estimation of their phytotoxicity to the cultivated crop. These methods enable to determine also dif­fe­ren­ces in the sensitivity of cultivars and/or hybrids to individual herbicides. The advantage of these methods consists above all in the speed and accuracy of measuring.In a field experiment, the sensitivity of several selected grain maize hybrids (EDENSTAR, NK AROBASE, NK LUGAN, LG 33.30 and NK THERMO to the herbicide CALLISTO 480 SC + ATPLUS 463 was tested for a period of three years. The sensitivity to a registered dose of 0.25 l . ha−1 + 0.5 % was measured by means of the apparatus PS1 meter, which could measure the reflected radiation. Measurements of sensitivity of hybrids were performed on the 2nd, 3rd, 4th, 5th and 8th day after the application of the tested herbicide, i.e. in the growing stage of the 3rd–5th leaf. Plant material was harvested using a small-plot combine harvester SAMPO 2010. Samples were weighed and converted to the yield with 15 % of moisture in grain DM.The obtained three-year results did not demonstrate differences in sensitivity of tested hybrids to the registered dose of the herbicide CALLISTO 480 SC + ATPLUS 463 (i.e. 0.25 l . ha−1 + 0,5 %. Recorded results indicated that for the majority of tested hybrids the most critical were the 4th and the 5th day after the application; on these days the average PS1 values were the highest at all. In years 2005 and 2007, none of the tested hybrids exceeded the limit value 15 (which indicated a certain decrease in the efficiency of photosynthesis. Although in 2006 three of tested hybrids showed a certain decrease in photosynthetic activity (i.e. EDENSTAR and NK AROBASE on the 3rd day and NK LUGAN on the 2nd–4th day after the application, no visual symptoms

  18. Seletividade de herbicidas, aplicados em pós-emergência, às plantas de alfafa Selectivity of applied port-emergence herbicides in the alfafa plants

    Directory of Open Access Journals (Sweden)

    Gláucia de Mello

    2000-08-01

    Full Text Available Foram conduzidos doi experimentos na UNESP/Jaboticabal, em casa-de-vegetação, com o objetivo de avaliar-se a toxicidade de diferentes herbicidas, aplicados em pós-emergênica, às plantas de alfafa. No primeiro, utilizou-se de um delineamento experimental com parcelas inteiramente casualizadas para avaliar-se os efeitos fitotóxicos dos seguintes herbicidas: MSMA, clethodim + óleo mineral, lactofen, fluazifop-pbutil, fomesafen + óleo mineral haloxyfop-methyl + óleo mineral, fenoxaprop-ethyl, chlorimuronethyl, halosulfuron + óleo mineral, nicosulfuron, acifluorfen, imazethapyr, bentazon + óleo mineral e cyanazine + simazine, todos em só dose. Foram feitas avaliações da fitotoxicidade por meio de notas, atribuídas visualmente, em função dos sintomas constatados nas plantas. A altura das plantas e o peso da matéria seca da parte área foram avaliadas no período de desenvolvimento inicial e após a primeira rebrota. No segundo experimento foi seguido mesmo esquema de instalação e condução do anterior, após escolherse os herbicidas e doses, sendo eles, o MSMA, chlorimuron-ethyl, imazethapyr, bentazon + óleo mineral, clethodim, clethodim + óleo mineral e bentazon + MSMA. Os herbicidas mais seletivos às plantas de alfafa foram haloxyfop-methyl, fluazifop-p-butil, fenoxaprop-ethyl, MSMA, imazethapyr, bentazon e clethodim isolado e adicionado de óleo mineral.Two experiments were carried out in a greenhouse, belonging to the Departamento de Defesa Fitissanitária da Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal/UNESP, with the purpose of evaluating the selectivity of different used post-emergence herbicides on alfafa plants. The experimental design was completely randomized to evaluate the phytotoxical effects of following herbicides: MSMA, clethodim plus mineral oil, lactofen, fluazifop-p-butil, fomesafen plus mineral oil, haloxyfop-methyl plus mineral oil, chlorimuron-ethyl, halosulfuron plus mineral oil

  19. Low Impact Development Master Plan

    Energy Technology Data Exchange (ETDEWEB)

    Loftin, Samuel R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-02

    This project creates a Low Impact Development (LID) Master Plan to guide and prioritize future development of LID projects at Los Alamos National Laboratory (LANL or the Laboratory). The LID Master Plan applies to developed areas across the Laboratory and focuses on identifying opportunities for storm water quality and hydrological improvements in the heavily urbanized areas of Technical Areas 03, 35 and 53. The LID Master Plan is organized to allow the addition of LID projects for other technical areas as time and funds allow in the future.

  20. Seletividade de herbicidas pós-emergentes aplicados na soja geneticamente modificada Selectivity of post-emergence herbicides applied on genetically modified soybeans

    Directory of Open Access Journals (Sweden)

    M.E.F. Neto

    2009-06-01

    pelo fato de o herbicida ser registrado para controle em pré-emergência e ter sido aplicado em pós-emergência. Nenhum dos tratamentos influenciou significativamente a produção de grãos da cultura da soja. A aplicação única ou a complementação com aplicação sequencial de glyphosate promoveram excelente controle de Commelina benghalensis e Ipomoea triloba.The experiment was carried out in a Roundup Ready® commercial soybean field in the Pontal do Paranapanema region in Euclides da Cunha Paulista-SP, located 20º 43' 11'' S and 50º 10' 20'' W, 270 m altitude. The experimental phase was carried out from December 2006 to April 2007, under no-tillage system. The soil classification is sandy clay loam Argisol. This work aimed to evaluate the efficiency of Roundup Transorb® glyphosate formulation selectivity associated with the herbicides diclosulam, cloransulam-methyl, flumioxazina and S-metolachlor under two spray modalities (single, with glyphosate associated to the herbicides and sequential, with only glyphosate in tropical Spiderwort (Commelina benghalensis and little bell (Ipomoea triloba management during soybean cultivation. The experiment was arranged in a randomized block design, with 12 treatments and 4 replications. Treatments were distributed in a factorial scheme + 2 controls (no control and clean field. The factorial scheme 2 x 5 comprises two herbicide sprays (single and sequential and five herbicides (glyphosate, glyphosate + diclosulam, glyphosate + cloransulam-methyl, glyphosate + flumioxazin and glyphosate + S-metolachlor. Under the conditions and time the herbicides were used as well as spray dosage, the results showed that glyphosate sprayed in a single dose or sequentially, in combination with diclosulan and cloransulam-methyl in the first spray did not cause phyto-intoxication in the soybean plants. The flumioxazin and S-metolachlor combination promoted delay in the growing plants as well as in the complete formation of the culture due

  1. Seletividade de herbicidas aplicados em pré-emergência na cultura do algodão Selectivity of herbicides applied to pre-emergent cotton crops

    Directory of Open Access Journals (Sweden)

    Miriam Hiroko Inoue

    2013-03-01

    Full Text Available A cultura do algodão tem grande importância econômica e social, visto que é a fibra mais utilizada no setor têxtil. Contudo é uma cultura que apresenta alta sensibilidade a plantas daninhas e há poucos herbicidas seletivos à cultura. Neste contexto o trabalho objetivou avaliar a seletividade de herbicidas aplicados em pré-emergência na cultura do algodão. Os herbicidas alachlor, S-metolachlor, diuron, prometryne, trifluralin e oxyfluorfen foram aplicados isoladamente e em misturas sobre a variedade FMT-701, nas localidades de Diamantino-MT e Campos de Júlio-MT. O delineamento experimental utilizado foi em blocos casualizados com 16 tratamentos e 4 repetições. Para avaliar a seletividade foram realizadas avaliações de altura aos 36; 66 e 150 dias após a aplicação (DAA, fitointoxicação aos 14; 21; 29 e 36 DAA, estande aos 21 e 49 DAA, número de maçãs aos 141 DAA e produtividade do algodão em caroço aos 193 DAA. Os dados foram submetidos à análise conjunta e ao teste de agrupamento Scott-Knott (p>0,05. Os resultados indicaram que alguns tratamentos proporcionaram menor altura de plantas em determinadas avaliações e grande parte dos tratamentos causou injúrias na fase inicial da cultura. Verificou-se que os tratamentos não proporcionaram diferença significativa para as características de estande de plantas, número de maçãs e produtividade de algodão em caroço, comprovando que todos os tratamentos avaliados podem ser utilizados no manejo de plantas daninhas.The cultivation of cotton has great economic and social importance as it is the most widely used fibre in the textile sector. It is however a crop that is highly sensitive tweeds, and there are few selective herbicides for the crop. With this in mind, this study aimed to evaluate the selectivity of herbicides applied to pre-emergent cotton crops. The herbicides, alachlor, S-metolachlor, diuron, prometryne, trifluralin and oxyfluorfen were applied both

  2. Seletividade de herbicidas aplicados na grama Batatais e na grama São Carlos Selectivity of herbicides applied on Bahiagrass and Broadleaf Carpetgrass turfs

    Directory of Open Access Journals (Sweden)

    N.V. Costa

    2010-06-01

    Full Text Available Objetivou-se avaliar a seletividade de herbicidas aplicados na grama Batatais (Paspalum notatum e na grama São Carlos (Axonopus compressus em campo. O delineamento experimental utilizado foi o de blocos casualizados com quatro repetições. As gramas foram cortadas a 3 cm de altura e, em seguida, realizaram-se as aplicações dos herbicidas. Os tratamentos utilizados foram: testemunha (sem aplicação, fluazifop-p-butil (125 g ha-1, sethoxydim+óleo mineral (276 g ha-1 + 0,5% v v-1 de Assist, bispyribac-sodium (25 g ha-1, chlorimuron-ethyl (15 g ha-1, ethoxysulfuron (150 g ha-1, halosulfuron (112,5 g ha-1, iodosulfuron-methyl (10 g ha-1, metsulfuron-methyl (2,4 g ha-1, nicosulfuron (125 g ha-1, pyrithiobac-sodium (140 g ha-1, trifloxysulfuron-sodium (22,5 g ha-1, 2,4-D (720 g ha-1, quinclorac (375 g ha-1, atrazina (1.250 g ha-1, bentazon (600 g ha-1, linuron (1.350 g ha-1, fomesafen (187,5 g ha-1, lactofen (120 g ha-1, oxadiazon (600 g ha-1 e oxyfluorfen (720 g ha-1. Os herbicidas que apresentaram potencial de seletividade para o gramado de P. notatum foram o chlorimuron-ethyl, ethoxysulfuron, pyrithiobac-sodium, 2,4-D, bentazon e fomesafen; já para o gramado de A. compressus foram o chlorimuron-ethyl, ethoxysulfuron, halosulfuron, iodosulfuron-methyl, metsulfuron-methyl, pyrithiobac-sodium, 2,4-D, quinclorac, atrazina, bentazon, além do fomesafen.The objective of this study was to evaluate the selectivity of herbicides applied on Bahiagrass (Paspalum notatum and Broadleaf Carpetgrass (Axonopus compressus turfgrasses under field conditions. The experiment was arranged in a randomized block design, with four replications. The turfgrasses were cut to the height of 3 cm, followed by herbicide application.. The treatments were: control, fluazifop-p-butyl (125 g ha-1, sethoxydim+mineral oil (276 g ha-1 + 0.5% v v-1 of Assist, bispyribac-sodium (25 g ha-1, chlorimuron-ethyl (15 g ha-1, ethoxysulfuron (150 g ha-1, halosulfuron (112.5 g ha-1

  3. Semi-automated solid phase extraction method for the mass spectrometric quantification of 12 specific metabolites of organophosphorus pesticides, synthetic pyrethroids, and select herbicides in human urine.

    Science.gov (United States)

    Davis, Mark D; Wade, Erin L; Restrepo, Paula R; Roman-Esteva, William; Bravo, Roberto; Kuklenyik, Peter; Calafat, Antonia M

    2013-06-15

    Organophosphate and pyrethroid insecticides and phenoxyacetic acid herbicides represent important classes of pesticides applied in commercial and residential settings. Interest in assessing the extent of human exposure to these pesticides exists because of their widespread use and their potential adverse health effects. An analytical method for measuring 12 biomarkers of several of these pesticides in urine has been developed. The target analytes were extracted from one milliliter of urine by a semi-automated solid phase extraction technique, separated from each other and from other urinary biomolecules by reversed-phase high performance liquid chromatography, and detected using tandem mass spectrometry with isotope dilution quantitation. This method can be used to measure all the target analytes in one injection with similar repeatability and detection limits of previous methods which required more than one injection. Each step of the procedure was optimized to produce a robust, reproducible, accurate, precise and efficient method. The required selectivity and sensitivity for trace-level analysis (e.g., limits of detection below 0.5ng/mL) was achieved using a narrow diameter analytical column, higher than unit mass resolution for certain analytes, and stable isotope labeled internal standards. The method was applied to the analysis of 55 samples collected from adult anonymous donors with no known exposure to the target pesticides. This efficient and cost-effective method is adequate to handle the large number of samples required for national biomonitoring surveys. Published by Elsevier B.V.

  4. Photosensitized herbicidal action

    Energy Technology Data Exchange (ETDEWEB)

    Zweig, A; Nachtigall, G W [American Cyanamid Co., Stamford, Conn.

    1975-12-01

    The herbicidal action produced by the colorless hydrocarbon fluoranthene sprayed on the leaves of growing plants did not occur when uv radiation was removed from the light to which the plants are exposed. If the uv component of the light under which the plants were grown was augmented, the herbicidal effect of fluoranthene was increased. The mechanism of this photodynamic action is discussed.

  5. Herbicide Safeners Decrease Sensitivity to Herbicides Inhibiting Acetolactate-Synthase and Likely Activate Non-Target-Site-Based Resistance Pathways in the Major Grass Weed Lolium sp. (Rye-Grass)

    OpenAIRE

    Duhoux, Arnaud; Pernin, Fanny; Desserre, Diane; D?lye, Christophe

    2017-01-01

    Herbicides are currently pivotal to control weeds and sustain food security. Herbicides must efficiently kill weeds while being as harmless as possible for crops, even crops taxonomically close to weeds. To increase their selectivity toward crops, some herbicides are sprayed in association with safeners that are bioactive compounds exacerbating herbicide-degrading pathways reputedly specifically in crops. However, exacerbated herbicide metabolism is also a key mechanism underlying evolved non...

  6. Uses of thaxtomin and thaxtomin compositions as herbicides

    Energy Technology Data Exchange (ETDEWEB)

    Koivunen, Marja; Marrone, Pamela

    2016-12-27

    There is a need for a selective, low-risk herbicide that can be used to control weeds in cereal cultures and turf. The present invention discloses that a bacterial secondary metabolite, thaxtomin and optionally another herbicide is an effective herbicide on broadleaved, sedge and grass weeds. Thaxtomin A and structurally similar compounds can be used as natural herbicides to control the germination and growth of weeds in cereal, turf grass, Timothy grass and pasture grass cultures with no phytotoxicity to these crops. As a natural, non-toxic compound, thaxtomin can be used as a safe alternative for weed control in both conventional and organic farming and gardening systems.

  7. Rationale for Selection of Pesticides, Herbicides, and Related Compounds from the Hanford SST/DST Waste Considered for Analysis in Support of the Regulatory DQO (Privatization)

    Energy Technology Data Exchange (ETDEWEB)

    Wiemers, K.D.; Daling, P.; Meier, K.

    1999-01-04

    Regulated pesticides, herbicides, miticides, and fungicides were evaluated for their potential past and current use at the Hanford Site. The starting list of these compounds is based on regulatory analyte input lists discussed in the Regulatory DQO. Twelve pesticide, herbicide, miticide, and fungicide compounds are identified for analysis in the Hanford SST and DST waste in support of the Regulatory DQO. The compounds considered for additional analyses are non-detected, considered stable in the tank waste matrix, and of higher toxicity/carcinogenicity.

  8. Rationale for Selection of Pesticides, Herbicides, and Related Compounds from the Hanford SST/DST Waste Considered for Analysis in Support of the Regulatory DQO (Privatization)

    International Nuclear Information System (INIS)

    Wiemers, K.D.; Daling, P.; Meier, K.

    1999-01-01

    Regulated pesticides, herbicides, miticides, and fungicides were evaluated for their potential past and current use at the Hanford Site. The starting list of these compounds is based on regulatory analyte input lists discussed in the Regulatory DQO. Twelve pesticide, herbicide, miticide, and fungicide compounds are identified for analysis in the Hanford SST and DST waste in support of the Regulatory DQO. The compounds considered for additional analyses are non-detected, considered stable in the tank waste matrix, and of higher toxicity/carcinogenicity

  9. Herbicide-resistant crops: utilities and limitations for herbicide-resistant weed management.

    Science.gov (United States)

    Green, Jerry M; Owen, Micheal D K

    2011-06-08

    Since 1996, genetically modified herbicide-resistant (HR) crops, particularly glyphosate-resistant (GR) crops, have transformed the tactics that corn, soybean, and cotton growers use to manage weeds. The use of GR crops continues to grow, but weeds are adapting to the common practice of using only glyphosate to control weeds. Growers using only a single mode of action to manage weeds need to change to a more diverse array of herbicidal, mechanical, and cultural practices to maintain the effectiveness of glyphosate. Unfortunately, the introduction of GR crops and the high initial efficacy of glyphosate often lead to a decline in the use of other herbicide options and less investment by industry to discover new herbicide active ingredients. With some exceptions, most growers can still manage their weed problems with currently available selective and HR crop-enabled herbicides. However, current crop management systems are in jeopardy given the pace at which weed populations are evolving glyphosate resistance. New HR crop technologies will expand the utility of currently available herbicides and enable new interim solutions for growers to manage HR weeds, but will not replace the long-term need to diversify weed management tactics and discover herbicides with new modes of action. This paper reviews the strengths and weaknesses of anticipated weed management options and the best management practices that growers need to implement in HR crops to maximize the long-term benefits of current technologies and reduce weed shifts to difficult-to-control and HR weeds.

  10. Methods of analysis by the U.S. Geological Survey Organic Geochemistry Research Group : determination of selected herbicides and their degradation products in water using solid-phase extraction and gas chromatography/mass spectrometry

    Science.gov (United States)

    Kish, J.L.; Thurman, E.M.; Scribner, E.A.; Zimmerman, L.R.

    2000-01-01

    A method for the extraction and analysis of eight herbicides and five degradation products using solid-phase extraction from natural water samples followed by gas chromatography/mass spectrometry is presented in this report. This method was developed for dimethenamid; flufenacet; fluometuron and its degradation products, demethylfluometuron (DMFM), 3-(trifluromethyl)phenylurea (TFMPU), 3-(trifluromethyl)-aniline (TFMA); molinate; norflurazon and its degradation product, demethylnorflurazon; pendamethalin; the degradation product of prometryn, deisopropylprometryn; propanil; and trifluralin. The eight herbicides are used primarily in the southern United States where cotton, rice, and soybeans are produced. The exceptions are dimethenamid and flufenacet, which are used on corn in the Midwest. Water samples received by the U.S. Geological Survey's Organic Geochemistry Research Group in Lawrence, Kansas, are filtered to remove suspended particulate matter and then passed through disposable solid-phase extraction columns containing octadecyl-bonded porous silica (C-18) to extract the compounds. The herbicides and their degradation products are removed from the column by ethyl acetate elution. The eluate is evaporated under nitrogen, and components then are separated, identified, and quantified by injecting an aliquot of the concentrated extract into a high-resolution, fused-silica capillary column of a gas chromatograph/mass spectrometer under selected-ion mode. Method detection limits ranged from 0.02 to 0.05 ?g/L for all compounds with the exception of TFMPU, which has a method detection limit of 0.32 ?g/L. The mean absolute recovery is 107 percent. This method for the determination of herbicides and their degradation products is valuable for acquiring information about water quality and compound fate and transport in water.

  11. DNA analysis of herbarium Specimens of the grass weed Alopecurus myosuroides reveals herbicide resistance pre-dated herbicides.

    Science.gov (United States)

    Délye, Christophe; Deulvot, Chrystel; Chauvel, Bruno

    2013-01-01

    Acetyl-CoA carboxylase (ACCase) alleles carrying one point mutation that confers resistance to herbicides have been identified in arable grass weed populations where resistance has evolved under the selective pressure of herbicides. In an effort to determine whether herbicide resistance evolves from newly arisen mutations or from standing genetic variation in weed populations, we used herbarium specimens of the grass weed Alopecurus myosuroides to seek mutant ACCase alleles carrying an isoleucine-to-leucine substitution at codon 1781 that endows herbicide resistance. These specimens had been collected between 1788 and 1975, i.e., prior to the commercial release of herbicides inhibiting ACCase. Among the 734 specimens investigated, 685 yielded DNA suitable for PCR. Genotyping the ACCase locus using the derived Cleaved Amplified Polymorphic Sequence (dCAPS) technique identified one heterozygous mutant specimen that had been collected in 1888. Occurrence of a mutant codon encoding a leucine residue at codon 1781 at the heterozygous state was confirmed in this specimen by sequencing, clearly demonstrating that resistance to herbicides can pre-date herbicides in weeds. We conclude that point mutations endowing resistance to herbicides without having associated deleterious pleiotropic effects can be present in weed populations as part of their standing genetic variation, in frequencies higher than the mutation frequency, thereby facilitating their subsequent selection by herbicide applications.

  12. economics of herbicide weed management in wheat in ethiopia ...

    African Journals Online (AJOL)

    ACSS

    Effective use of herbicides for the control of annual grass and broadleaf weeds in wheat (Triticum aestivum L.) was not a reality in Ethiopia, until in recent years. This study aimed at evaluating different post-emergence herbicides against annual grasses and broadleaf weeds in wheat for selection and incorporation into an ...

  13. Expanding the eco-evolutionary context of herbicide resistance research.

    Science.gov (United States)

    Neve, Paul; Busi, Roberto; Renton, Michael; Vila-Aiub, Martin M

    2014-09-01

    The potential for human-driven evolution in economically and environmentally important organisms in medicine, agriculture and conservation management is now widely recognised. The evolution of herbicide resistance in weeds is a classic example of rapid adaptation in the face of human-mediated selection. Management strategies that aim to slow or prevent the evolution of herbicide resistance must be informed by an understanding of the ecological and evolutionary factors that drive selection in weed populations. Here, we argue for a greater focus on the ultimate causes of selection for resistance in herbicide resistance studies. The emerging fields of eco-evolutionary dynamics and applied evolutionary biology offer a means to achieve this goal and to consider herbicide resistance in a broader and sometimes novel context. Four relevant research questions are presented, which examine (i) the impact of herbicide dose on selection for resistance, (ii) plant fitness in herbicide resistance studies, (iii) the efficacy of herbicide rotations and mixtures and (iv) the impacts of gene flow on resistance evolution and spread. In all cases, fundamental ecology and evolution have the potential to offer new insights into herbicide resistance evolution and management. © 2014 Society of Chemical Industry.

  14. Seletividade de herbicidas aplicados em pré-emergência na cultura de cana-de-açúcar tratada com nematicidas Selectivity of pre-emergence herbicides to sugarcane treated with nematicides

    Directory of Open Access Journals (Sweden)

    E. Negrisoli

    2004-12-01

    Full Text Available O objetivo do trabalho foi estudar a seletividade de herbicidas para a cultura da cana-de-açúcar quando aplicado em culturas tratadas com nematicidas. O experimento foi instalado em área pertencente à Usina São José, município de Borebi-SP, ano agrícola de 2000/01. A variedade de cana-de-açúcar utilizada foi a RB855113. Utilizou-se o delineamento experimental de blocos ao acaso em parcelas subdivididas, com quatro repetições. Cada parcela correspondeu a 27 linhas de 10,0 m, espaçadas em 1,0 m, sendo dividida em três subparcelas. As parcelas corresponderam aos tratamentos com os herbicidas, e as subparcelas, à aplicação ou não dos nematicidas carbofuran (2,10 kg ha-1 e terbufós 2,25 kg ha��. Os herbicidas testados foram: tebuthiuron (1,12 kg ha-1, ametryne (1,75 kg ha¹, sulfentrazone (0,8 kg ha-1, metribuzin (1,92 kg ha-1, isoxaflutole (0,0525 kg ha¹, clomazone (1,25 kg ha¹, oxyfluorfen (0,36 kg ha-1 e azafenidin+hexazinone (0,1575 + 0,2025 kg ha-1, sendo todos aplicados em pré-emergência, além de uma parcela como testemunha. Os resultados obtidos evidenciaram que os herbicidas oxyfluorfen e azafenidin+hexazinone causaram os maiores níveis de fitotoxicidade na cana-de-açúcar, independentemente do uso dos nematicidas carbofuran e terbufós. Os herbicidas tebuthiuron, ametryne, sulfentrazone, metribuzin, isoxaflutole, clomazone, oxyfluorfen e azafenidin+hexazinone, aplicados em doses representativas das comercialmente utilizadas, mostraram-se seletivos à cana-de-açúcar, não afetando seu crescimento, sua produtividade e suas características tecnológicas. Os nematicidas não interferiram nos níveis de intoxicação provocados pelos herbicidas utilizados na cultura.The objective of this work was to study the selectivity of herbicides to sugarcane when applied in crops treated with nematicides. The experiment was carried out in Borebi, São Paulo-Brazil, during the growing season 2000/2001. The sugar cane variety

  15. Annual Herbicide Loadings

    Data.gov (United States)

    U.S. Environmental Protection Agency — Pesticides, Herbicides, Fungicides...etc, are used for a variety of purposes, including control of household, lawn, and garden pests; for control of mosquitoes and...

  16. Seletividade de herbicidas aplicados em pós-emergência sobre capim-colonião e efeito na qualidade das sementes: effects on seed germination Selectivity of herbicides applied in post-emergence on grass forage

    Directory of Open Access Journals (Sweden)

    L.R.C. Trigueiro

    2007-01-01

    Full Text Available Este estudo foi conduzido para avaliar a seletividade de herbicidas aplicados em pós-emergência sobre plantas de Panicum maximum, cultivares Tanzânia e Mombaça, e os seus efeitos na qualidade das sementes. Os tratamentos testados (em g ha-1 foram: diclofopmethyl (284, ametryne (1.250, propanil (3.600, chlorimuron-ethyl (15, nicosulfuron (50, bentazon (720 e atrazine (3.000, além de uma testemunha sem aplicação de herbicidas. Foram instalados dois experimentos a campo, um para cada cultivar, no delineamento em blocos casualizados com quatro repetições, e um em laboratório, no delineamento inteiramente casualizado, com 16 repetições. O nicosulfuron foi o herbicida que mais causou injúrias visuais e redução de massa seca de plantas em ambos os cultivares. No cultivar Mombaça, todos os herbicidas reduziram a produção de sementes, mas não afetaram a germinação. Para o cultivar Tanzânia, todos os herbicidas foram seletivos, não afetando a produção e a qualidade fisiológica.This study aimed to evaluate the selectivity of some herbicides applied in post-emergence on Panicum maximum cv. Tanzânia and Mombaça and their effect on seed quality. The treatments tested in g ha-1 were: diclofop-methyl at 284, ametryn at 1.250, propanyl at 3.600, chlorimuron-ethyl at 15, nicosulfuron at 50, bentazon at 720 and atrazine at 3.000, and a control plot without herbicide application. Two field trials, one to each cultivar, were carried out in a randomized complete block design, with 4 replications and one laboratory trial was carried out in a randomized complete design, with 16 replications. Nicosulfuron showed the highest levels of visual damage and largest plant dry matter reduction in both cultivars. All the herbicides showed seed production decrease in Mombaca but did not affect seed germination. All the herbicides were selective to cultivar Tanzania, with no damages to plant production and physiological quality.

  17. Seletividade de herbicidas registrados para a cultura do milho aos estádios imaturos de Trichogramma pretiosum (Hymenoptera: Trichogrammatidae Selectivity of herbicides registered for corn at the immature stages of Trichogramma pretio sum (Hymenoptera: Trichogrammatidae

    Directory of Open Access Journals (Sweden)

    G.J Stefanello Jr

    2011-01-01

    Full Text Available O controle químico tem sido um dos métodos mais utilizados para o manejo de plantas daninhas na cultura do milho, no entanto o uso de herbicidas pode ocasionar efeitos adversos aos insetos benéficos, como os parasitoides de ovos. Nesse sentido, foi avaliada a seletividade de 12 herbicidas registrados para a cultura do milho para as fases imaturas de Trichogramma pretiosum em condições de laboratório (temperatura de 25±1 ºC, umidade relativa de 70±10% e fotofase de 14 horas. Os herbicidas foram diluídos em um volume proporcional a 200 L de água por hectare e pulverizados sobre ovos de lepidóptero contendo formas imaturas do parasitoide em seu interior, nas fases de ovo-larva, pré-pupa e pupa. Avaliou-se, então, a porcentagem de emergência dos parasitoides e, em função da comparação com a testemunha, classificaram-se os herbicidas em inócuo (classe 1, 99%. Os herbicidas Agrisato 480 SL, Finale, Glifos, Glifosato Nortox, Gliz 480 SL, Polaris, Roundup Original, Roundup Transorb, Roundup WG, Trop e Zapp Qi foram inócuos (classe 1 às diferentes fases imaturas de T. pretiosum e são considerados seletivos ao parasitoide. Gramoxone 200, embora tenha sido inócuo para as fases de ovo-larva e pré-pupa, foi considerado levemente nocivo (classe 2 para a fase de pupa. Nesse sentido, para melhor compatibilização do manejo químico das plantas daninhas e controle biológico de insetos, sugere-se que sejam utilizados, sempre que possível, aqueles herbicidas que permitem maior sobrevivência de T. pretiosum.- Chemical control has been one of the most widely used methods for weed mana gement in corn. However, the use of herbicides can cause adverse effects on beneficial insects, such as egg parasitoids. Thus, this work aimed to evaluate the selectivity of 12 herbicides regis tered for corn at the immature stages of Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae under laboratory conditions (temperature 25±1 o C

  18. Effects of herbicides on fish

    DEFF Research Database (Denmark)

    Solomon, Keith R.; Dalhoff, Kristoffer; Volz, David

    2013-01-01

    Herbicides are used to control weeds and are usually targeted to processes and target sites that are specific to plants. As a result, most herbicides are not acutely toxic to fish. Exceptions to this general rule are uncouplers of oxidative phosphorylation and some herbicides that interfere...... with cell division. Chronic and sublethal effects have been studied for some herbicides, but fewer data are available for these effects than for acute effects. The sublethal effects of herbicides that have been studied include reproduction, stress, olfaction, and behavior. Although some of these responses......, and reproduction. As with all pesticides, herbicides may have indirect effects in fish. These effects are mediated by herbicide-induced changes in food webs or in the physical environment. Indirect effects can only occur if direct effects occur first and would be mediated by the killing of plants by herbicides...

  19. Herbicide options for hardwood management

    Science.gov (United States)

    Andrew W. Ezell; A. Brady Self

    2016-01-01

    The use of herbicides in hardwood management presents special problems in that many of the most effective herbicides are either designed to control hardwoods or the product is not labeled for such applications. Numerous studies involving herbicide application in hardwoods have been completed at Mississippi State University. This paper is a compilation of results from...

  20. Seletividade de herbicidas: II - aplicação de herbicidas em pós-emergência inicial e tarida da cana-de-açúcar na época das chuvas Herbicide selectivity: II - herbicide application at initial and late and post-emergence of sugarcane in the rainy season

    Directory of Open Access Journals (Sweden)

    C.A.M. Azania

    2005-12-01

    Full Text Available Objetivou-se com este trabalho testar a seletividade dos herbicidas diuron+hexazinone, azafenidin+hexazinone, metribuzin e isoxaflutole, aplicados em pósemergência inicial e tardia das plantas de cana-de-açúcar, cultivar RB835089, na época das chuvas, em soqueira de terceiro corte, após colheita com queima prévia do canavial, em Araras-SP. O delineamento experimental foi o de blocos casualizados com testemunhas pareadas, com cinco tratamentos e quatro repetições, existindo uma testemunha capinada para cada tratamento químico dentro de cada bloco. Os tratamentos foram: diuron+hexazinone (1.170+330 g ha-1, azafenidin+hexazinone (192,5+247,5 g ha-1, metribuzin (1.920 g ha-1, isoxaflutole (127,5 g ha-1 e testemunha. Concluiu-se que os herbicidas foram mais fitotóxicos quando aplicados na pós-emergência tardia. Em pós-emergência inicial, o isoxaflutole foi o único produto que afetou a produtividade agrícola. Na pós-emergência tardia, todos os herbicidas prejudicaram a produtividade agrícola, sendo o diuron+hexazinone o único produto que não afetou as características tecnológicas e o rendimento de açúcar.This research aimed to evaluate the selectivity of azafenidin+hexazinone, diuron+hexazinone, metribuzin and isoxaflutole to sugarcane, applied at initial and late post-emergence during the rainy season. The study was conducted over 3-yr sugarcane ratoons (cv. RB 835089, in Araras, SP. The experiment was arranged in randomized blocks with five treatments and four replications, and one weeded control for each treatment within each block. The treatments used were: (diuron+hexazinone (1,170 + 330 g ha-1, azafenidin+hexazinone (192.5+247.5 g ha-1, metribuzin (1,920 g ha-1 and isoxaflutole (127.5 g ha-1 and weed control. It was concluded that the herbicides damaged sugarcane the most when applied during late post-emergence. At early post-emergence, isoxaflutole was the only herbicide affecting yield. In late post-emergence, all the

  1. [Effects of herbicide on grape leaf photosynthesis and nutrient storage].

    Science.gov (United States)

    Tan, Wei; Wang, Hui; Zhai, Heng

    2011-09-01

    Selecting three adjacent vineyards as test objects, this paper studied the effects of applying herbicide in growth season on the leaf photosynthetic apparatus and branch nutrient storage of grape Kyoho (Vitis vinfrraxVitis labrusca). In the vineyards T1 and T2 where herbicide was applied in 2009, the net photosynthesis rate (Pa) of grape leaves had a significant decrease, as compared with that in vineyard CK where artificial weeding was implemented. The leaves at the fourth node in vineyard T1 and those at the sixth node in vineyard T2 had the largest decrement of Pn (40.5% and 32.1%, respectively). Herbicide had slight effects on the leaf stomatal conductance (Gs). In T1 where herbicide application was kept on with in 2010, the Pn, was still significantly lower than that in CK; while in T2 where artificial weeding was implemented in 2010, the Pn and Gs of top- and middle node leaves were slightly higher than those in T1, but the Pn was still lower than that in CK, showing the aftereffects of herbicide residual. The herbicide application in 2009 decreased the leaf maximum photochemical efficiency of PS II (Fv/Fm) and performance index (P1) while increased the relative variable fluorescence in the J step and K step, indicating the damage of electron transportation of PS II center and oxygen-evolving complex. Herbicide application decreased the pigment content of middle-node leaves in a dose-manner. Applying herbicide enhanced the leaf catalase and peroxidase activities significantly, increased the superoxide dismutase (SOD) activity of middle-node leaves, but decreased the SOD activity of top- and bottom node leaves. After treated with herbicide, the ascorbate peroxidase (APX) activity of middle- and bottom node leaves increased, but that of top-node leaves decreased. Herbicide treatment aggravated leaf lipid peroxidation, and reduced the soluble sugar, starch, free amino acids, and soluble protein storage in branches.

  2. Seletividade de herbicidas aplicados em pré-emergência da cultura da cana-de-açúcar (RB 867515 tratada com nematicidas Selectivity of herbicides applied on pre-emergence of nematicide-treated sugarcane crop (RB 867515

    Directory of Open Access Journals (Sweden)

    J.F. Barela

    2006-06-01

    Full Text Available A aplicação simultânea de duas ou mais classes de defensivos sobre uma cultura agrícola pode provocar toxicidade às plantas. Assim, conduziu-se um experimento com o objetivo de avaliar a seletividade de herbicidas à cultura da cana-de-açúcar (RB 867515, quando aplicados em condição de pré-emergência, em áreas previamente tratadas com nematicidas no sulco de plantio. O experimento foi desenvolvido em área comercial de produção de cana-de-açúcar, no município de Piracicaba - SP, entre abril de 2003 e julho de 2004. Os tratamentos resultaram da combinação entre nove fatores herbicidas e quatro fatores nematicidas. Os herbicidas usados no experimento foram: sulfentrazone, tebuthiuron, metribuzin, ametrina, diuron, clomazone, pendimethalin e diuron + hexazinone, além de uma testemunha capinada. Os nematicidas utilizados foram: carbofuran, terbufós, aldicarb e uma testemunha sem nematicida. Avaliou-se a fitotoxicidade das diferentes combinações aos 15, 30, 60 e 90 dias após a brotação, o rendimento (t ha-1 e os parâmetros tecnológicos qualitativos. Observou-se que a seletividade inicial dos herbicidas foi prejudicada em função da interação das diferentes classes de defensivos utilizadas. Os sintomas de fitotoxicidade foram agudos, e os casos mais evidentes se originaram da associação dos nematicidas com clomazone, pendimethalin e tebuthiuron. Contudo, os danos fitotóxicos não se refletiram em perdas significativas de rendimento ou de qualidade de colmos, fato esse que pode ter sido influenciado pela capacidade de recuperação de injúrias apresentada pela variedade RB 867515, pela ocorrência de altas infestações de nematóides ou pela elevada variabilidade experimental.Simultaneous applications of two or more classes of herbicides on a crop may promote ,totoxicity in the plants. Therefore, an experiment was conducted to evaluate herbicide selectivity in sugarcane, when applied under pre-emergence condition, in

  3. Sensitivity to Glufosinate-ammonium herbicide in plants of Glycine max cultivar INCASoy-27

    Directory of Open Access Journals (Sweden)

    Jorge Liusvert Pérez Pérez

    2014-10-01

    Full Text Available This work had as objective to define the minimum concentration of herbicide Glufosinate-ammonium that inhibits the growth of the soybean plants in greenhouse condition. The soybean plants were tried with different concentrations of herbicide (5; 10; 1 5; 20; 25; 30 mg L-1 and a control without herbicide. The increase of the concentrations increased the necrosis of the plants and the use of 20 mgL-1 Glufosinato de amonio herbicide was sufficient to inhibit the plant growth. These results allow using this method of selection in programs of genetic improvement and selection of transgenic soybean plants

  4. Effect of sugarcane cropping systems on herbicide losses in surface runoff.

    Science.gov (United States)

    Nachimuthu, Gunasekhar; Halpin, Neil V; Bell, Michael J

    2016-07-01

    Herbicide runoff from cropping fields has been identified as a threat to the Great Barrier Reef ecosystem. A field investigation was carried out to monitor the changes in runoff water quality resulting from four different sugarcane cropping systems that included different herbicides and contrasting tillage and trash management practices. These include (i) Conventional - Tillage (beds and inter-rows) with residual herbicides used; (ii) Improved - only the beds were tilled (zonal) with reduced residual herbicides used; (iii) Aspirational - minimum tillage (one pass of a single tine ripper before planting) with trash mulch, no residual herbicides and a legume intercrop after cane establishment; and (iv) New Farming System (NFS) - minimum tillage as in Aspirational practice with a grain legume rotation and a combination of residual and knockdown herbicides. Results suggest soil and trash management had a larger effect on the herbicide losses in runoff than the physico-chemical properties of herbicides. Improved practices with 30% lower atrazine application rates than used in conventional systems produced reduced runoff volumes by 40% and atrazine loss by 62%. There were a 2-fold variation in atrazine and >10-fold variation in metribuzin loads in runoff water between reduced tillage systems differing in soil disturbance and surface residue cover from the previous rotation crops, despite the same herbicide application rates. The elevated risk of offsite losses from herbicides was illustrated by the high concentrations of diuron (14μgL(-1)) recorded in runoff that occurred >2.5months after herbicide application in a 1(st) ratoon crop. A cropping system employing less persistent non-selective herbicides and an inter-row soybean mulch resulted in no residual herbicide contamination in runoff water, but recorded 12.3% lower yield compared to Conventional practice. These findings reveal a trade-off between achieving good water quality with minimal herbicide contamination and

  5. CADDIS Volume 2. Sources, Stressors and Responses: Herbicides

    Science.gov (United States)

    Introduction to the herbicides module, when to list herbicides as a candidate cause, ways to measure herbicides, simple and detailed conceptual diagrams for herbicides, herbicides module references and literature reviews.

  6. Changes in bacterial community after application of three different herbicides.

    Science.gov (United States)

    Moretto, Jéssica Aparecida Silva; Altarugio, Lucas Miguel; Andrade, Pedro Avelino; Fachin, Ana Lúcia; Andreote, Fernando Dini; Stehling, Eliana Guedes

    2017-07-06

    The native soil microbiota is very important to maintain the quality of that environment, but with the intensive use of agrochemicals, changes in microbial biomass and formation of large quantities of toxic waste were observed in soil, groundwater and surface water. Thereby, the goal of this study was to evaluate if the selective pressure exerted by the presence of the herbicides atrazine, diuron and 2,4-D changes the bacterial community structure of an agricultural soil, using denaturing gradient gel electrophoresis technique. According to PERMANOVA analysis, a greater effect of the herbicide persistence time in the soil, the effect of the herbicide class and the effect of interaction between these two factors (persistence time and herbicide class) were observed. In conclusion, the results showed that the selective pressure exerted by the presence of these herbicides altered the composition of the local microbiota, being atrazine and diuron that most significantly affected the bacterial community in soil, and the herbicide 2,4-D was the one that less altered the microbial community and that bacterial community was reestablished first. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Avaliação de diferentes herbicidas para erradicação química de coqueiros infectados com resinose Herbicide selection for chemical eradication of coconut palms infected with stem-bleeding

    Directory of Open Access Journals (Sweden)

    H.R. Fontes

    2009-01-01

    Full Text Available Objetivou-se neste trabalho selecionar herbicidas que possam ser utilizados na erradicação química de coqueiros infectados com resinose. O experimento foi instalado no município de Neópolis - SE, no período de junho a julho de 2007. Utilizou-se uma população de coqueiros da variedade anão-verde, implantada há 11 anos. O delineamento experimental foi o inteiramente casualizado, em parcelas subdivididas no tempo, com cinco repetições (cada unidade experimental foi composta por um coqueiro infectado. Os tratamentos foram formados pela combinação de dez tratamentos herbicidas {MSMA (36 g por planta; glyphosate (18 g por planta; paraquat (10 g por planta; [2,4-D + picloram] (18 + 1,125 g por planta; [2,4-D + picloram] + paraquat ([9 + 0,5625] + 5 g por planta; MSMA + glyphosate (18 + 9 g por planta; MSMA + paraquat (18 + 5 g por planta; glyphosate + paraquat (9 + 5 g por planta; [2,4-D + picloram] + MSMA ([9 + 0,5625] + 18 g por planta; tratamento controle (testemunha sem aplicação} e de quatro épocas de avaliação (7, 14, 21 e 28 dias após a aplicação dos tratamentos herbicidas. Os herbicidas foram injetados no estipe dos coqueiros em um furo de 25 cm de profundidade, 5 cm de diâmetro e inclinação de 45º, localizado a 1,0 m de altura. A aplicação foi realizada por intermédio de uma seringa graduada, imediatamente após a abertura dos furos, sendo os herbicidas aplicados sem diluição. Foram realizadas quatro avaliações da dessecação dos coqueiros, aos 7, 14, 21 e 28 dias após a aplicação dos tratamentos (DAA. O herbicida MSMA foi o que resultou na dessecação mais rápida dos coqueiros doentes, além de promover a morte de todas as plantas avaliadas, sendo por isso o tratamento mais indicado na continuação dos estudos visando à proposição de uma técnica para a erradicação química de coqueiros infectados com resinose.The objective of this work was to select herbicides that can be used to chemically

  8. Seletividade de herbicidas aplicados em pré-emergência, isolados e em misturas, na cultura do algodão = Selective of applied herbicides in pre-emergency, isolated and in mixtures, in the culture of the cotton.

    Directory of Open Access Journals (Sweden)

    Miriam Hiroko Inoue

    2012-08-01

    Full Text Available A cultura do algodão tem grande importância econômica e social, visto que é a fibra mais utilizada no setor têxtil. Contudo, apresenta alta sensibilidade a plantas daninhas e há poucos herbicidas seletivos à cultura. Neste contexto objetivouse com este trabalho avaliar a seletividade de herbicidas aplicados em pré-emergência na cultura do algodão. Os herbicidas alachlor, S-metolachlor, diuron, prometryne, trifluralin e oxyfluorfen foram aplicados isoladamente e em misturas sobre a variedade FMT-701, nas localidades de Diamantino-MT e Campos de Júlio-MT. O delineamento experimental utilizado foiem blocos casualizados com 16 tratamentos e 4 repetições. Para avaliar a seletividade foram realizadas avaliações de alturaaos 36, 66 e 150 dias após a aplicação (DAA, fitointoxicação aos 14, 21, 29 e 36 DAA, estande aos 21 e 49 DAA, número de maçãs aos 141 DAA e produtividade do algodão em caroço aos 193 DAA. Os resultados indicaram que grande parte dos tratamentos causou injúrias na fase inicial da cultura e alguns tratamentos também proporcionaram menor altura de plantas em determinadas avaliações. Verificou-se ainda que os tratamentos não proporcionaram diferença significativa no estande de plantas, no número de maçãs e nem na produtividade de algodão em caroço, evidenciando que todos os tratamentos avaliados podem ser utilizados no manejo de plantas daninhas.The culture of the cotton has great economic and social importance, because it is the fiber more frequently used in the textile section. However, the crop has high sensibility to weed and there are few selective herbicides for this crop. In this context, the objective of this study was to evaluate the selectivity of applied herbicides in pre-emergency on the culture of the cotton. The herbicides alachlor, S-metolachlor, diuron, prometryne, trifluralin and oxyfluorfen were separately applied and in mixtures with the variety FMT-701, in the places of Diamantino

  9. Herbicides in environmental pollution

    International Nuclear Information System (INIS)

    Qureshi, M.J.; Haq, A.; Maqbool, U.

    1997-01-01

    Herbicide effectiveness on the most pernicious weeds including cyperus rotundus may be limited because spray droplets are not well retained or because penetration and/or translocation is restricted. As a result, chemical pollute the environment and is hazardous to the human health. Monitoring studies ad undertaken to check that the flate and environmental effects of herbicides under field condition are consistent with prediction. Studies on /sup 14/-glyphosate in Cyperus rotundus using radiotracer methods indicated that out of five formulations studies formulation No.3 was the best from penetration point of view of the chemical whereas formulation No. 4 with the high dose showed effective retention and uniform translocation of the chemical after five days of the treatment. Cuticular penetration and translocation of glyphosate in the formulations with or without surfactants have also been studied in C. rotundus. It is also concluded that synperonic surfactants, diesel oil or glycerol did not influence the translocation of glyphosate within the weed. The translocation mainly occurred down swards and accumulated in the plant parts located below the treated zone. (author)

  10. Palmistichus elaeisis (Hymenoptera: Eulophidae as an indicator of toxicity of herbicides registered for corn in Brazil

    Directory of Open Access Journals (Sweden)

    Claubert W.G de Menezes

    2014-09-01

    Full Text Available The diversity of plants in agricultural systems benefits natural enemies. Herbicides are used in weed management in corn (Zea mays L. to reduce competition and productivity losses, but they can impact natural enemies and contaminate the environment. The objective was to evaluate toxicity of herbicides on pupae parasitoid Palmistichus elaeisis Delvare and LaSalle, 1993 (Hymenoptera: Eulophidae. The treatments were represented by the host pupae Tenebrio molitor L., 1785 (Coleoptera: Tenebrionidae and herbicides atrazine, nicosulfuron, paraquat, and tembotrione in commercial doses compared to a control treatment with water. Pupae of T. molitor were immersed in the solution of herbicides and exposed to parasitism by six females of P. elaeisis each. The herbicides atrazine and paraquat were highly toxic and, therefore, not selective to P. elaeisis. Nicosulfuron reduced the sex ratio of P. elaeisis (0.20 ± 0.03, which may affect subsequent generations. Moreover, the herbicide tembotrione was selective to P. elaeisis, showing results comparable to the control. Floristic diversity of weeds can increase food source, habitat, shelter, breeding places and microclimates for insect parasitoids but herbicides formulations can be toxic and these products can affect P. elaeisis or its hosts by direct or indirect contact, showing the importance of selectivity studies for this natural enemy. However, the herbicide tembotrione was selective to P. elaeisis and it can be recommended for programs of sustainable management of weeds in corn crop with this parasitoid.

  11. Limited fitness costs of herbicide-resistance traits in Amaranthus tuberculatus facilitate resistance evolution

    Science.gov (United States)

    The fitness cost of herbicide resistance (HR) in the absence of herbicide selection plays a key role in HR evolution. Quantifying the fitness cost of resistance, however, is challenging, and there exists a knowledge gap in this area. A synthetic Amaranthus tuberculatus population segregating for fiv...

  12. Predictive value of species sensitivity distributions for effects of herbicides in freshwater ecosystems

    NARCIS (Netherlands)

    Brink, van den P.J.; Blake, N.; Brock, T.C.M.; Maltby, L.

    2006-01-01

    In this article we present a review of the laboratory and field toxicity of herbicides to aquatic ecosystems. Single-species acute toxicity data and ( micro) mesocosm data were collated for nine herbicides. These data were used to investigate the importance of test species selection in constructing

  13. Urban base flow with low impact development

    Science.gov (United States)

    Bhaskar, Aditi; Hogan, Dianna M.; Archfield, Stacey A.

    2016-01-01

    A novel form of urbanization, low impact development (LID), aims to engineer systems that replicate natural hydrologic functioning, in part by infiltrating stormwater close to the impervious surfaces that generate it. We sought to statistically evaluate changes in a base flow regime because of urbanization with LID, specifically changes in base flow magnitude, seasonality, and rate of change. We used a case study watershed in Clarksburg, Maryland, in which streamflow was monitored during whole-watershed urbanization from forest and agricultural to suburban residential development using LID. The 1.11-km2 watershed contains 73 infiltration-focused stormwater facilities, including bioretention facilities, dry wells, and dry swales. We examined annual and monthly flow during and after urbanization (2004–2014) and compared alterations to nearby forested and urban control watersheds. We show that total streamflow and base flow increased in the LID watershed during urbanization as compared with control watersheds. The LID watershed had more gradual storm recessions after urbanization and attenuated seasonality in base flow. These flow regime changes may be because of a reduction in evapotranspiration because of the overall decrease in vegetative cover with urbanization and the increase in point sources of recharge. Precipitation that may once have infiltrated soil, been stored in soil moisture to be eventually transpired in a forested landscape, may now be recharged and become base flow. The transfer of evapotranspiration to base flow is an unintended consequence to the water balance of LID.

  14. Seletividade e eficiência agronômica de herbicidas no controle de capim-colchão na cultura da melancia Selectivity and agronomic efficiency of herbicides over Digitaria horizontalis control in the watermelon crop

    Directory of Open Access Journals (Sweden)

    Cleber D.G. Maciel

    2002-09-01

    Full Text Available Foi avaliada a seletividade e a eficiência agronômica dos herbicidas clethodim e sethoxydim, no controle de Digitaria horizontalis (capim-colchão na cultura da melancia (cv. Crimson Sweet. O experimento foi conduzido em campo, no município de Floresta, PR, em 1995/96, em delineamento de blocos ao acaso, com quatro repetições. Os tratamentos avaliados foram clethodim nas doses de 84; 96 e 108 g i.a./ha adicionado de 1,0 L/ha de óleo mineral (Dytrol, sethoxydim na dose de 230 g i.a./ha adicionado de 1,0 L/ha de óleo mineral (Assist e testemunhas com e sem capina. Os herbicidas foram aplicados em pós-emergência, quando a melancia apresentava ramas com 1,4 m e a D. horizontalis em estádio de três folhas a três perfilhos e densidade de 240 plantas/m². Para a aplicação dos herbicidas utilizou-se pulverizador costal de pressão mantida por injeção de CO2, equipado com pontas de jato plano XR110.02 e volume de calda de 200 L/ha. As avaliações de seletividade (Escala E.W.R.C. e controle das plantas daninhas (0 - 100% foram efetuadas aos 7; 15 e 30 dias após aplicação dos tratamentos. Os resultados indicaram que o herbicida clethodim, a partir de 96 g i.a./ha, controlou eficientemente a D. horizontalis, sendo estatisticamente superior ao herbicida sethoxydim e à testemunha sem capina. Nenhum dos tratamentos químicos causou fitotoxicidade que afetasse o desenvolvimento e a produção da melancia. A D. horizontalis interferiu no desenvolvimento da cultura, causando redução média de 36,0% da produção da melancia.The selectivity and agronomic efficiency of clethodim and sethoxydim herbicides on D. horizontalis control in watermelon crop was evaluated. The experiment was carried out at Floresta, Paraná State, Brazil, in 1995/96. The watermelon cultivar used was Crimson Sweet and the experimental design was a randomized block with four replicates. The treatments evaluated were clethodim (240 g/L in the dosage of 84; 96, 108 g i

  15. Natural compounds as next-generation herbicides.

    Science.gov (United States)

    Dayan, Franck E; Duke, Stephen O

    2014-11-01

    Herbicides with new modes of action (MOAs) are badly needed due to the rapidly evolving resistance to commercial herbicides, but a new MOA has not been introduced in over 20 years. The greatest pest management challenge for organic agriculture is the lack of effective natural product herbicides. The structural diversity and evolved biological activity of natural phytotoxins offer opportunities for the development of both directly used natural compounds and synthetic herbicides with new target sites based on the structures of natural phytotoxins. Natural phytotoxins are also a source for the discovery of new herbicide target sites that can serve as the focus of traditional herbicide discovery efforts. There are many examples of strong natural phytotoxins with MOAs other than those used by commercial herbicides, which indicates that there are molecular targets of herbicides that can be added to the current repertoire of commercial herbicide MOAs. © 2014 American Society of Plant Biologists. All Rights Reserved.

  16. Relationship between weed dormancy and herbicide rotations: implications in resistance evolution.

    Science.gov (United States)

    Darmency, Henri; Colbach, Nathalie; Le Corre, Valérie

    2017-10-01

    It is suggested that selection for late germinating seed cohorts is significantly associated with herbicide resistance in some cropping systems. In turn, it is conceivable that rotating herbicide modes of action selects for populations with mutations for increased secondary dormancy, thus partially overcoming the delaying effect of rotation on resistance evolution. Modified seed dormancy could affect management strategies - like herbicide rotation - that are used to prevent or control herbicide resistance. Here, we review the literature for data on seed dormancy and germination dynamics of herbicide-resistant versus susceptible plants. Few studies use plant material with similar genetic backgrounds, so there are few really comparative data. Increased dormancy and delayed germination may co-occur with resistance to ACCase inhibitors, but there is no clear-cut link with resistance to other herbicide classes. Population shifts are due in part to pleiotropic effects of the resistance genes, but interaction with the cropping system is also possible. We provide an example of a model simulation that accounts for genetic diversity in the dormancy trait, and subsequent consequences for various cropping systems. We strongly recommend adding more accurate and detailed mechanistic modelling to the current tools used today to predict the efficiency of prevention and management of herbicide resistance. These models should be validated through long-term experimental designs including mono-herbicide versus chemical rotation in the field. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  17. Phorate can reverse P450 metabolism-based herbicide resistance in Lolium rigidum.

    Science.gov (United States)

    Busi, Roberto; Gaines, Todd Adam; Powles, Stephen

    2017-02-01

    Organophosphate insecticides can inhibit specific cytochrome P450 enzymes involved in metabolic herbicide resistance mechanisms, leading to synergistic interactions between the insecticide and the herbicide. In this study we report synergistic versus antagonistic interactions between the organophosphate insecticide phorate and five different herbicides observed in a population of multiple herbicide-resistant Lolium rigidum. Phorate synergised with three different herbicide modes of action, enhancing the activity of the ALS inhibitor chlorsulfuron (60% LD 50 reduction), the VLCFAE inhibitor pyroxasulfone (45% LD 50 reduction) and the mitosis inhibitor trifluralin (70% LD 50 reduction). Conversely, phorate antagonised the two thiocarbamate herbicides prosulfocarb and triallate with a 12-fold LD 50 increase. We report the selective reversal of P450-mediated metabolic multiple resistance to chlorsulfuron and trifluralin in the grass weed L. rigidum by synergistic interaction with the insecticide phorate, and discuss the putative mechanistic basis. This research should encourage diversity in herbicide use patterns for weed control as part of a long-term integrated management effort to reduce the risk of selection of metabolism-based multiple herbicide resistance in L. rigidum. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  18. Oxidative stress caused by the use of preemergent herbicides in rice crops

    Directory of Open Access Journals (Sweden)

    Ana Claudia Langaro

    Full Text Available ABSTRACT Among the methods of weed control, stands out chemical control. However, even selective, herbicides can trigger the production of reactive species of oxygen and cause oxidative stress. The aim of the study was to evaluate changes in photosynthetic parameters, oxidative damage, antioxidant enzyme activity and altered metabolism of rice plants after applying pre-emergent herbicides. The experiment was conducted in a greenhouse and herbicides used were oxadiazon, pendimethalin and oxyfluorfen, beyond the control without herbicide. There was a reduction of photosynthetic rate and efficiency of carboxylation, compared to the control, when applied herbicides oxyfluorfen and pendimethalin. The major lipid peroxidation and proline accumulation was observed for the herbicide oxyfluorfen. The oxyfluorfen and oxadiazon herbicides also resulted in increased activity of superoxide dismutase, compared to control. When evaluated ascorbate peroxidase activity, there was a higher enzyme activity in plants treated with oxadiazon and pendimethalin. Even selective herbicides registered for weed control in rice crops cause phytotoxicity, reduce height and alter the metabolism of plants, generating reactive oxygen species, which activate enzymatic and non-enzymatic defense systems and result in the degradation of photosynthetic pigments and in reduced protein content.

  19. Spot Spraying Reduces Herbicide Concentrations in Runoff.

    Science.gov (United States)

    Melland, Alice R; Silburn, D Mark; McHugh, Allen D; Fillols, Emilie; Rojas-Ponce, Samuel; Baillie, Craig; Lewis, Stephen

    2016-05-25

    Rainfall simulator trials were conducted on sugar cane paddocks across dry-tropical and subtropical Queensland, Australia, to examine the potential for spot spraying to reduce herbicide losses in runoff. Recommended rates of the herbicides glyphosate, 2,4-D, fluoroxypyr, atrazine, and diuron were sprayed onto 0, 20, 40, 50, 70, or 100% of the area of runoff plots. Simulated rainfall was applied 2 days after spraying to induce runoff at one plant cane and three ratoon crop sites. Over 50% of all herbicides were transported in the dissolved phase of runoff, regardless of the herbicide's sediment-water partition coefficient. For most sites and herbicides, runoff herbicide concentrations decreased with decreasing spray coverage and with decreasing herbicide load in the soil and cane residues. Importantly, sites with higher infiltration prior to runoff and lower total runoff had lower runoff herbicide concentrations.

  20. A herbicide structure-activity analysis of the antimalarial lead compound MMV007978 against Arabidopsis thaliana.

    Science.gov (United States)

    Corral, Maxime G; Leroux, Julie; Tresch, Stefan; Newton, Trevor; Stubbs, Keith A; Mylne, Joshua S

    2018-07-01

    To fight herbicide-resistant weeds, new herbicides are needed; particularly ones with new modes of action. Building on the revelation that many antimalarial drugs are herbicidal, here we focus on the Medicines for Malaria Venture antimalarial lead compound MMV007978 that has herbicidal activity against the model plant Arabidopsis thaliana. Twenty-two variations of the lead compound thiophenyl motif revealed that change was tolerated provided ring size and charge were retained. MMV007978 was active against select monocot and dicot weeds, and physiological profiling indicated that its mode of action is related to germination and cell division. Of interest is the fact that the compound has a profile that is currently not found among known herbicides. We demonstrate that the antimalarial compound MMV007978 is also herbicidal and that exploiting lead compounds that are often understudied could lead to the identification of interesting herbicidal scaffolds. Further structural investigation of MMV007978 could provide improved herbicidal chemistries with a potential new mode of action. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  1. Structural and functional effects of herbicides on non-target organisms in aquatic ecosystems with an emphasis on atrazine

    Science.gov (United States)

    Fairchild, James; Kortekamp, Andreas

    2011-01-01

    Herbicide use has increased dramatically around the world over the past 6 decades (Gianessi and Reigner, 2007). Few herbicides were in use in the 1950s. However, by 2001 approximately 1.14 billion kilograms of herbicides were applied globally for the control of undesireable vegetation in agricultural, silvicultural, lawncare, aquacultural, and irrigation/recreational water management activities (Kiely et al., 2004). Twenty-eight percent of the total mass of herbicides is applied in the United States, with the remaining 72 percent being applied elsewhere around the globe (Kiely et al., 2004). Herbicides represent 36% of global pesticide use, followed by insecticides (25%), fungicides (10%) and other chemical classes (Kiely et al., 2004). Agricultural production accounts for approximately 90% of herbicide use in the U.S. (Kiely et al., 2004). Gianessi and Reigner (2007) indicated that herbicides are routinely used on more than 90% of the area designated for large commercial crops including corn, soybeans, cotton, sugar beets, peanuts, and rice. Increased farm mechanization, technological advancements in production of inexpensive sources of inorganic nitrogen fertilizer (e.g., anhydrous ammonia), and conversion of forest, grassland, and wetland habitats to cropland has led to a tremendous increase in global food production over the past half-century. Herbicides have augmented advances in large-scale agricultural systems and have largely replaced mechanical and hand-weeding control mechanisms (Gianessi and Reigner, 2007). The wide-spread use of herbicides in agriculture has resulted in frequent chemical detections in surface and groundwaters (Gilliom, 2007). The majority of herbicides used are highly water soluble and are therefore prone to runoff from terrestrial environments. In additon, spray drift and atmospheric deposition can contribute to herbicide contamination of aquatic environments. Lastly, selected herbicides are deliberately applied to aquatic environments

  2. Natural compounds with herbicidal activity

    Directory of Open Access Journals (Sweden)

    Mariano Fracchiolla

    2007-12-01

    Full Text Available Research about phytotoxic activity of natural compounds could lead both to find new herbicidal active ingredients and to plan environmental friendly weed control strategies. Particularly, living organisms could be a source of compounds that are impossible, for their complexity, to synthesize artificially. More over, they could have alternative sites of action respect to the known chemical herbicides and, due to their origin, they should be more environmental safe. Many living organism, such as bacteria, fungi, insects, lichens and plants, are able to produce bioactive compounds. They generally are secondary metabolites or simply waste molecules. In this paper we make a review about these compounds, highlighting potential and constraints.

  3. Natural compounds with herbicidal activity

    Directory of Open Access Journals (Sweden)

    Pasquale Montemurro

    2011-02-01

    Full Text Available Research about phytotoxic activity of natural compounds could lead both to find new herbicidal active ingredients and to plan environmental friendly weed control strategies. Particularly, living organisms could be a source of compounds that are impossible, for their complexity, to synthesize artificially. More over, they could have alternative sites of action respect to the known chemical herbicides and, due to their origin, they should be more environmental safe. Many living organism, such as bacteria, fungi, insects, lichens and plants, are able to produce bioactive compounds. They generally are secondary metabolites or simply waste molecules. In this paper we make a review about these compounds, highlighting potential and constraints.

  4. Comparisons of Herbicide Treated and Cultivated Herbicide-Resistant Corn

    Directory of Open Access Journals (Sweden)

    H. Arnold Bruns

    2010-01-01

    Full Text Available Four glyphosate resistant corn (Zea mays L. hybrids, a glufosinate-ammonium resistant hybrid, and a conventional atrazine resistant hybrid gown at Stoneville, MS in 2005, 2006, and 2007 with furrow irrigation were treated with their respective herbicides and their growth, yield, and mycotoxin incidence were compared with untreated cultivated plots. Leaf area index (LAI and dry matter accumulation (DMA were collected on a weekly basis beginning at growth stage V3 and terminating at anthesis. Crop growth rates (CRGs and relative growth rates (RGRs were calculated. Plots were later harvested, yield and yield component data collected, and kernel samples analyzed for aflatoxin and fumonisin. Leaf area index, DMA, CRG, and RGR were not different among the herbicide treated plots and from those that were cultivated. Curves for LAI and DMA were similar to those previously reported. Aflatoxin and fumonisin were relatively low in all plots. Herbicide application or the lack thereof had no negative impact on the incidence of kernel contamination by these two mycotoxins. Herbicides, especially glyphosate on resistant hybrids, have no negative effects on corn yields or kernel quality in corn produced in a humid subtropical environment.

  5. Controlled Release Formulations of Auxinic Herbicides

    Science.gov (United States)

    Kowalski, Witold J.; Siłowiecki, Andrzej.; Romanowska, Iwona; Glazek, Mariola; Bajor, Justyna; Cieciwa, Katarzyna; Rychter, Piotr

    2013-04-01

    Controlled release formulations are applied extensively for the release of active ingredients such as plant protection agents and fertilizers in response to growing concern for ecological problems associated with increased use of plant protection chemicals required for intensive agricultural practices [1]. We synthesized oligomeric mixtures of (R,S)-3-hydroxy butyric acid chemically bonded with 2,4-D, Dicamba and MCPA herbicides (HBA) respectively, and determined their molecular structure and molecular weight dispersion by the size exclusion chromatography, proton magnetic resonance spectrometry and electro-spray ionization mass spectrometry. Further we carried out bioassays of herbicidal effectiveness of the HBA herbicides vs. series of dicotyledonous weeds and crop injury tests [2, 3, 4]. Field bioassays were accomplished according to the EPPO standards [5]. Groups of representative weeds (the development stages in the BCCH scale: 10 - 30) were selected as targets. Statistical variabilities were assessed by the Fisher LSD test for plants treated with the studied herbicides in form of HBA oligomers, the reference herbicides in form of dimethyl ammonium salts (DMA), and untreated plants. No statistically significant differences in the crop injuries caused by the HBA vs. the DMA reference formulation were observed. The effectiveness of the HBA herbicides was lower through the initial period (ca. 2 weeks) relative to the DMA salts, but a significant increase in the effectiveness of the HBA systems followed during the remaining fraction of each assay. After 6 weeks all observed efficiencies approached 100%. The death of weeds treated with the HBA herbicides was delayed when compared with the DMA reference herbicides. The delayed uptake observed for the HBA oligomers relative to the DMA salts was due to controlled release phenomena. In case of the DMA salts the total amount of active ingredients was available at the target site. By contrast, the amount of an active

  6. Weed control changes and genetically modified herbicide tolerant crops in the USA 1996-2012.

    Science.gov (United States)

    Brookes, Graham

    2014-01-01

    Crops that have been genetically modified (GM) to be tolerant to herbicides have been widely grown in the USA since 1996. The rapid and widespread adoption of this technology reflects the important economic and environmental benefits that farmers have derived from its use (equal to $21.7 billion additional farm income and a 225 million kg reduction in herbicide active ingredient use 1996-2012). During this time, weed control practices in these crops relative to the 'conventional alternative' have evolved to reflect experience of using the technology, the challenges that have arisen and the increasing focus in recent years on developing sustainable production systems. This paper examines the evidence on the changing nature of herbicides used with these crops and in particular how farmers addressed the challenge of weed resistance. The evidence shows that use of the technology has resulted in a net reduction in both the amount of herbicide used and the associated environmental impact, as measured by the EIQ indicator when compared to what can reasonably be expected if the area planted to GM HT crops reverted to conventional production methods. It also facilitated many farmers being able to derive the economic and environmental benefits associated with switching from a plough-based to a no tillage or conservation tillage production system. In terms of herbicide use, the technology has also contributed to a change the profile of herbicides used. A broad range of, mostly selective herbicides has been replaced by one or 2 broad-spectrum herbicides (mostly glyphosate) used in conjunction with one or 2 other (complementary) herbicides. Since the mid-2000s, the average amount of herbicide applied and the associated environmental load, as measured by the EIQ indicator, have increased on both GM HT and conventional crops. A primary reason for these changes has been increasing incidence of weed species developing populations resistant to herbicides and increased awareness of

  7. Biotechnology: herbicide-resistant crops

    Science.gov (United States)

    Transgenic, herbicide-resistant (HR) crops are planted on about 80% of the land covered by transgenic crops. More than 90% of HR crios are glyphosate-resistant (GR) crops, the others being resistant to glufosinate. The wide-scale adoption of HR crops, largely for economic reasons, has been the mos...

  8. Low impact plutonium glovebox D ampersand D

    International Nuclear Information System (INIS)

    Rose, R.W.

    1995-01-01

    A dilemma often encountered in decontamination and decommissioning operations is the lack of choice as to the location where the work is to be performed. Facility siting, laboratory location, and adjacent support areas were often determined based on criteria, which while appropriate at the time, are not always the most conducive to a D ampersand D project. One must learn to adapt and cope with as found conditions. High priority research activities, which cannot be interrupted, may be occurring in adjacent non-radiological facilities in the immediate vicinity where highly contaminated materials must be handled in the course of a D ampersand D operation. The execution of a project within such an environment involves a high level of coordination, cooperation, professionalism and flexibility among the project, the work force and the surrounding occupants. Simply moving occupants from the potentially affected area is not always an option and much consideration must be given in the selection of the D ampersand D methodology to be employed and the processes to be implemented. Determining project boundaries and the ensuring that adjacent occupants are included in the planning/scheduling of specific operations which impact their work area are important in the development of the safety envelope. Such was the case in the recent D ampersand D of 61 gloveboxes contaminated with plutonium and other transuranic nuclides at the Argonne National Laboratory-East site. The gloveboxes, which were used in Department of Energy research and development program activities over the past 30 years, were decontaminated to below transuranic waste criteria, size reduced, packaged and removed from Building 212 by Argonne National Laboratory personnel in conjunction with Nuclear Fuel Services, Inc. with essentially no impact to adjacent occupants

  9. Low impact plutonium glovebox D&D

    Energy Technology Data Exchange (ETDEWEB)

    Rose, R.W.

    1995-12-31

    A dilemma often encountered in decontamination and decommissioning operations is the lack of choice as to the location where the work is to be performed. Facility siting, laboratory location, and adjacent support areas were often determined based on criteria, which while appropriate at the time, are not always the most conducive to a D&D project. One must learn to adapt and cope with as found conditions. High priority research activities, which cannot be interrupted, may be occurring in adjacent non-radiological facilities in the immediate vicinity where highly contaminated materials must be handled in the course of a D&D operation. The execution of a project within such an environment involves a high level of coordination, cooperation, professionalism and flexibility among the project, the work force and the surrounding occupants. Simply moving occupants from the potentially affected area is not always an option and much consideration must be given in the selection of the D&D methodology to be employed and the processes to be implemented. Determining project boundaries and the ensuring that adjacent occupants are included in the planning/scheduling of specific operations which impact their work area are important in the development of the safety envelope. Such was the case in the recent D&D of 61 gloveboxes contaminated with plutonium and other transuranic nuclides at the Argonne National Laboratory-East site. The gloveboxes, which were used in Department of Energy research and development program activities over the past 30 years, were decontaminated to below transuranic waste criteria, size reduced, packaged and removed from Building 212 by Argonne National Laboratory personnel in conjunction with Nuclear Fuel Services, Inc. with essentially no impact to adjacent occupants.

  10. Effect of Temperature and Chemical Additives on the Efficacy of the Herbicides Glufosinate and Glyphosate in Weed Management of Liberty-Link and Roundup-Ready Soybeans

    OpenAIRE

    Pline, Wendy Ann

    1999-01-01

    The introduction of herbicide resistant crops offers producers many more options for weed control systems. These crops allow environmentally safe, non-selective herbicides to be used as selective herbicides, broadening the spectrum of weeds controlled, while not harming the crop. As these crops are very new on the market, investigation of their performance under various environmental conditions as well as in various weed control programs is needed. Liberty-link ® soybeans are resistant t...

  11. Herbicide Persistence in Seawater Simulation Experiments.

    Directory of Open Access Journals (Sweden)

    Philip Mercurio

    Full Text Available Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR. The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities. Very little degradation was recorded over the standard 60 d period (Experiment 1 so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated

  12. Herbicide Persistence in Seawater Simulation Experiments

    Science.gov (United States)

    Mercurio, Philip; Mueller, Jochen F.; Eaglesham, Geoff; Flores, Florita; Negri, Andrew P.

    2015-01-01

    Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR). The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities). Very little degradation was recorded over the standard 60 d period (Experiment 1) so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated flood plumes

  13. Comparisons of Herbicide Treated and Cultivated Herbicide-Resistant Corn

    OpenAIRE

    H. Arnold Bruns; Hamed K. Abbas

    2010-01-01

    Four glyphosate resistant corn (Zea mays L.) hybrids, a glufosinate-ammonium resistant hybrid, and a conventional atrazine resistant hybrid gown at Stoneville, MS in 2005, 2006, and 2007 with furrow irrigation were treated with their respective herbicides and their growth, yield, and mycotoxin incidence were compared with untreated cultivated plots. Leaf area index (LAI) and dry matter accumulation (DMA) were collected on a weekly basis beginning at growth stage V3 and terminating at anthesi...

  14. Mechanism of sulfonylurea herbicide resistance in the broadleaf weed, Kochia scoparia

    International Nuclear Information System (INIS)

    Saari, L.L.; Cotterman, J.C.; Primiani, M.M.

    1990-01-01

    Selection of kochia (Kochia scoparia) biotypes resistant to the sulfonylurea herbicide chlorsulfuron has occurred through the continued use of this herbicide in monoculture cereal-growing areas in the United States. The apparent sulfonylurea resistance observed in kochia was confirmed in greenhouse tests. Fresh and dry weight accumulation in the resistance kochia was 2- to >350-fold higher in the presence of four sulfonylurea herbicides as compared to the susceptible biotype. Acetolactate synthase (ALS) activity isolated from sulfonylurea-resistant kochia was less sensitive to inhibition by three classes of ALS-inhibiting herbicides, sulfonylureas, imidazolinones, and sulfonanilides. The decrease in ALS sensitivity to inhibition (as measured by the ratio of resistant I 50 to susceptible I 50 ) was 5- to 28-fold, 2- to 6-fold, and 20-fold for sulfonylurea herbicides, imidazolinone herbicides, and a sulfonanilide herbicide, respectively. No differences were observed in the ALS-specific activities or the rates of [ 14 C]chlorsulfuron uptake, translocation, and metabolism between susceptible and resistant kochia biotypes. The K m values for pyruvate using ALS from susceptible and resistant kochia were 2.13 and 1.74 mM, respectively. Based on these results, the mechanism of sulfonylurea resistance in this kochia biotype is due solely to a less sulfonylurea-sensitive ALS enzyme

  15. Early Identification of Herbicide Stress in Soybean (Glycine max (L.) Merr.) Using Chlorophyll Fluorescence Imaging Technology.

    Science.gov (United States)

    Li, Hui; Wang, Pei; Weber, Jonas Felix; Gerhards, Roland

    2017-12-22

    Herbicides may damage soybean in conventional production systems. Chlorophyll fluorescence imaging technology has been applied to identify herbicide stress in weed species a few days after application. In this study, greenhouse experiments followed by field experiments at five sites were conducted to investigate if the chlorophyll fluorescence imaging is capable of identifying herbicide stress in soybean shortly after application. Measurements were carried out from emergence until the three-to-four-leaf stage of the soybean plants. Results showed that maximal photosystem II (PS II) quantum yield and shoot dry biomass was significantly reduced in soybean by herbicides compared to the untreated control plants. The stress of PS II inhibiting herbicides occurred on the cotyledons of soybean and plants recovered after one week. The stress induced by DOXP synthase-, microtubule assembly-, or cell division-inhibitors was measured from the two-leaf stage until four-leaf stage of soybean. We could demonstrate that the chlorophyll fluorescence imaging technology is capable for detecting herbicide stress in soybean. The system can be applied under both greenhouse and field conditions. This helps farmers to select weed control strategies with less phytotoxicity in soybean and avoid yield losses due to herbicide stress.

  16. Sensor-based assessment of herbicide effects

    DEFF Research Database (Denmark)

    Streibig, Jens Carl; Rasmussen, Jesper; Andújar, D.

    2014-01-01

    Non-destructive assessment of herbicide effects may be able to support integrated weed management. To test whether effects of herbicides on canopy variables could be detected by sensors, two crops were used as models and treated with herbicides at BBCH 20 using a logarithmic sprayer. Twelve days...... after spraying at BBCH 25 and 42 days after sowing, nine sensor systems scanned a spring barley and an oilseed rape field experiment sown at different densities and sprayed with increasing field rates of glyphosate and tribenuron-methyl. The objective was to compare ED50s for crops and weeds derived...... by the different sensors in relation to crop density and herbicides. Although sensors were not directly developed to detect herbicide symptoms, they all detected changes in canopy colours or height and crop density. Generally ED50s showed the same pattern in response to crop density within herbicide...

  17. Sorption behaviour of herbicides in soils

    International Nuclear Information System (INIS)

    Luchini, L.C.; Wiendl, F.M.; Ruegg, E.F.; Instituto Biologico, Sao Paulo

    1988-01-01

    Environmental contamination by herbicides is related with the sorption phenomenon of these compounds in the soils. The behaviour of paraquat, 2,4-D and diuron was studied in soils with different physico-chemical properties, through the Freundlich adsorption and desorption isotherms, using 14 C-radiolabeled herbicides. Results of the range of the adsorption-desorption of each herbicide was related mainly with the chemical characteristics of these compounds. (author) [pt

  18. Delivery of calibration workshops covering herbicide application equipment : final report.

    Science.gov (United States)

    2014-03-31

    Proper herbicide sprayer set-up and calibration are critical to the success of the Oklahoma Department of Transportation (ODOT) herbicide program. Sprayer system set-up and calibration training is provided in annual continuing education herbicide wor...

  19. Cross-resistance to herbicides in annual ryegrass (lolium rigidum)

    International Nuclear Information System (INIS)

    Christopher, J.T.; Powles, S.B.; Liljegren, D.R.; Holtum, J.A.M.

    1991-01-01

    Lolium rigidum Gaud. biotype SLR31 is resistant to the herbicide diclofop-methyl and cross-resistant to several sulfonylurea herbicides. Wheat and the cross-resistant ryegrass exhibit similar patterns of resistance to sulfonylurea herbicides, suggesting that the mechanism of resistance may be similar. Cross-resistant ryegrass is also resistant to the wheat-selective imidazolinone herbicide imazamethabenz. The cross-resistant biotype SLR31 metabolized [phenyl-U- 14 C]chlorsulfuron at a faster rate than a biotype which is susceptible to both diclofop-methyl and chlorsulfuron. A third biotype which is resistant to diclofop-methyl but not to chlorsulfuron metabolized chlorsulfuron at the same rate as the susceptible biotype. The increased metabolism of chlorsulfuron observed in the cross-resistant biotype is, therefore, correlated with the patterns of resistance observed in these L. rigidum biotypes. During high performance liquid chromatography analysis the major metabolite of chlorsulfuron in both susceptible and cross-resistant ryegrass coeluted with the major metabolite produced in wheat. The major product is clearly different from the major product in the tolerant dicot species, flax (Linium usitatissimum). The elution pattern of metabolites of chlorsulfuron was the same for both the susceptible and cross-resistant ryegrass but the cross-resistant ryegrass metabolized chlorsulfuron more rapidly. The investigation of the dose response to sulfonylurea herbicides at the whole plant level and the study of the metabolism of chlorsulfuron provide two independent sets of data which both suggest that the resistance to chlorsulfuron in cross-resistant ryegrass biotype SLR31 involves a wheat-like detoxification system

  20. CADDIS Volume 2. Sources, Stressors and Responses: Herbicides - Detailed Conceptual Diagram

    Science.gov (United States)

    Introduction to the herbicides module, when to list herbicides as a candidate cause, ways to measure herbicides, simple and detailed conceptual diagrams for herbicides, herbicides module references and literature reviews.

  1. CADDIS Volume 2. Sources, Stressors and Responses: Herbicides - Simple Conceptual Diagram

    Science.gov (United States)

    Introduction to the herbicides module, when to list herbicides as a candidate cause, ways to measure herbicides, simple and detailed conceptual diagrams for herbicides, herbicides module references and literature reviews.

  2. FLAMMABILITY OF HERBICIDE-TREATED GUAVA FOLIAGE

    Science.gov (United States)

    Guava leaves treated with herbicide were found to be less flammable than untreated green leaves or dead leaves . Differences in flammability were...determined by small-scale laboratory fires, differential thermal analysis, and thermogravimetric analysis. The herbicide-treated leaves had a higher ash

  3. Response of Saw Palmetto to Three Herbicides

    Science.gov (United States)

    J.L. Michael; D.G. Neary

    1985-01-01

    Saw palmetto [Serona repens (Bartram) Small] can be controlled with herbicides. Garion® 4E1/2 and Brush Killer® 800 were evaluated for effectiveness againest saw palmetto when they were applied at three rates in April, June, and August. Oust® was tested at three rates in April only. Herbicides were not effective with April...

  4. Herbicide residues in grapes and wine.

    Science.gov (United States)

    Ying, G G; Williams, B

    1999-05-01

    The persistence of several common herbicides from grapes to wine has been studied. Shiraz, Tarrango and Doradillo grapes were separately sprayed with either norflurazon, oxyfluorfen, oxadiazon or trifluralin-persistent herbicides commonly used for weed control in vineyards. The dissipation of the herbicides from the grapes was followed for 28 days following treatment. Results showed that norflurazon was the most persist herbicide although there were detectable residues of all the herbicides on both red and white grapes at the end of the study period. The penetration of herbicides into the flesh of the grapes was found to be significantly greater for white grapes than for red grapes. Small-lot winemaking experiments showed that norflurazon persisted at levels close to the initial concentration through vinification and into the finished wine. The other herbicides degraded, essentially via first-order kinetics, within the period of "first fermentation" and had largely disappeared after 28 days. The use of charcoal together with filter pads, or with diatomaceous earth was shown to be very effective in removing herbicide residues from the wine. A 5% charcoal filter removed more than 96% of the norflurazon persisting in the treated wine.

  5. Control of Butterfly Bush with Postemergence Herbicides

    Science.gov (United States)

    Butterfly bush (Buddleja davidii) is classified as invasive in several parts of the United States. Two experiments were conducted to evaluate the effectiveness of four herbicides and two application methods on postemergence butterfly bush control. The four herbicides included: Roundup (glyphosate)...

  6. Imazapyr (herbicide) seed dressing increases yield, suppresses ...

    African Journals Online (AJOL)

    from damage. In 1998/99 season, a trial was initiated at Chitedze Research Station under artificial infection, to evaluate the effects of seed dressing with imazapyr (an acetolactate synthase {ALS} inhibiting herbicide) using three seed treatment methods (coating, priming or drenching) and three herbicide rates (15, 30 and 45 ...

  7. Environmental toxicology: Degradation of herbicides

    International Nuclear Information System (INIS)

    Corbin, F.T.; Monaco, T.J.; Bjelk, L.A.

    1991-01-01

    This chapter focuses on the advances that have been made for the quantitative analysis of radiotracers in thin-layer chromatography through the development of computer controlled imaging proportional counters (IPC). IPC has been developed to give high sensitivity digital data from an entire TLC separation in one measurement. The imaging capability provides a 100 percent improvement over mechanical scanners. Sensitivity is 100 DPM or less with 14 C and higher energy isotopes. Investigations of herbicide metabolism in plant cell suspension cultures are presented with procedures for the use of this technique

  8. Herbicides and their transformation products in source-water aquifers tapped by public-supply wells in Illinois, 2001-02

    Science.gov (United States)

    Mills, Patrick C.; McMillan, William D.

    2004-01-01

    During 2001-02, ground-water samples were collected from 117 public-supply wells distributed throughout Illinois to evaluate the occurrence of herbicides and their transformation products in the State?s source-water aquifers. Wells were selected using a stratified-random method to ensure representation of the major types of source-water aquifers in the State. Samples were analyzed for 18 herbicides and 18 transformation products, including 3 triazine and 14 chloroacetanilide products. Herbicide compounds (field-applied parent herbicides and their transformation products) were detected in 34 percent of samples. A subset of samples was collected unfiltered to determine if analytical results for herbicides in unfiltered samples are similar to those in paired filtered samples and, thus, can be considered equally representative of herbicide concentrations in ground water supplied to the public. The study by the U.S. Geological Survey was done in cooperation with the Illinois Environmental Protection Agency. Parent herbicides were detected in only 4 percent of all samples. The six most frequently detected herbicide compounds (from 5 to 28 percent of samples) were chloroacetanilide transformation products. The frequent occurrence of transformation products and their higher concentrations relative to those of most parent herbicides confirm the importance of obtaining information on transformation products to understand the mobility and fate of herbicides in ground-water systems. No sample concentrations determined during this study exceeded current (2003) Federal or State drinking-water standards; however, standards are established for only seven parent herbicides. Factors related to the occurrence of herbicide compounds in the State?s source-water aquifers include unconsolidated and unconfined conditions, various hydrogeologic characteristics and well-construction aspects at shallow depths, and proximity to streams. Generally, the closer an aquifer (or well location) is

  9. Photochemical oxidation processes for the elimination of phenyl-urea herbicides in waters

    International Nuclear Information System (INIS)

    Benitez, F. Javier; Real, Francisco J.; Acero, Juan L.; Garcia, Carolina

    2006-01-01

    Four phenyl-urea herbicides (linuron, chlorotoluron, diuron, and isoproturon) were individually photooxidized by monochromatic UV radiation in ultra-pure aqueous solutions. The influence of pH and temperature on the photodegradation process was established, and the first-order rate constants and quantum yields were evaluated. The sequence of photodecomposition rates was: linuron > chlorotoluron > diuron > isoproturon. The simultaneous photooxidation of mixtures of the selected herbicides in several types of waters was then performed by means of UV radiation alone, and by UV radiation combined with hydrogen peroxide. The types of waters used were: ultra-pure water, a commercial mineral water, a groundwater, and a lake water. The influence of the independent variables in these processes - the presence or absence of tert-butyl alcohol, types of herbicide and waters, and concentration of hydrogen peroxide - were established and discussed. A kinetic study was performed using a competitive kinetic model that allowed various rate constants to be evaluated for each herbicide. This kinetic model allows one to predict the elimination of these phenyl-urea herbicides in contaminated waters by the oxidation systems used (UV alone and combined UV/H 2 O 2 ). The herbicide concentrations predicted by this model agree well with the experimental results that were obtained

  10. Stress-physiological reactions of the green alga Scenedesmus opoliensis to water pollution with herbicides

    Directory of Open Access Journals (Sweden)

    Zsolt Gyula KERESZTES

    2009-05-01

    Full Text Available The freshwater green alga Scenedesmus opoliensis proves to be a suitable bioindicator of water pollution with different herbicides. One of the best molecular markers of stress condition imposed by herbicides is overproduction of malondialdehyde resulting from lipid peroxidation in the damaged membranes. Methylviologen, a largely used pre-emergence herbicide which generates reactive oxygen species in the illuminated chloroplasts, triggers the accumulation of ascorbic acid and enhances the enzymatic activity of catalase, both of these substances being involved in the antioxidative protection of algal cells. Diuron, a herbicide that inhibits photosynthetic electron transport on the acceptor side of photosystem II, causes a decline in oxygen production and in biomass accumulation of algae. Glufosinate induces accumulation of toxic ammonia and leads to enhanced net oxygen production, associated with a low rate of carbon assimilation. Long-term exposure to micromolar concentrations of herbicides results in significant changes in the rate of cell division, in hotosynthetic parameters and in the intensity of antioxidative defense. A proper bioindication of toxic effects of herbicides on algae requires a selected combination of different physiological and biochemical parameters which reflect the degree of stress exerted on living organisms by water pollution with xenobiotic organic compounds.

  11. Photochemical oxidation processes for the elimination of phenyl-urea herbicides in waters

    Energy Technology Data Exchange (ETDEWEB)

    Benitez, F. Javier [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)]. E-mail: javben@unex.es; Real, Francisco J. [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain); Acero, Juan L. [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain); Garcia, Carolina [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)

    2006-11-16

    Four phenyl-urea herbicides (linuron, chlorotoluron, diuron, and isoproturon) were individually photooxidized by monochromatic UV radiation in ultra-pure aqueous solutions. The influence of pH and temperature on the photodegradation process was established, and the first-order rate constants and quantum yields were evaluated. The sequence of photodecomposition rates was: linuron > chlorotoluron > diuron > isoproturon. The simultaneous photooxidation of mixtures of the selected herbicides in several types of waters was then performed by means of UV radiation alone, and by UV radiation combined with hydrogen peroxide. The types of waters used were: ultra-pure water, a commercial mineral water, a groundwater, and a lake water. The influence of the independent variables in these processes - the presence or absence of tert-butyl alcohol, types of herbicide and waters, and concentration of hydrogen peroxide - were established and discussed. A kinetic study was performed using a competitive kinetic model that allowed various rate constants to be evaluated for each herbicide. This kinetic model allows one to predict the elimination of these phenyl-urea herbicides in contaminated waters by the oxidation systems used (UV alone and combined UV/H{sub 2}O{sub 2}). The herbicide concentrations predicted by this model agree well with the experimental results that were obtained.

  12. Comparative sensitivity of Selenastrum capricornutum and Lemna minor to sixteen herbicides

    Science.gov (United States)

    Fairchild, J.F.; Ruessler, D.S.; Haverland, P.S.; Carlson, A.R.

    1997-01-01

    Aquatic plant toxicity tests are frequently conducted in environmental risk assessments to determine the potential impacts of contaminants on primary producers. An examination of published plant toxicity data demonstrates that wide differences in sensitivity can occur across phylogenetic groups of plants. Yet relatively few studies have been conducted with the specific intent to compare the relative sensitivity of various aquatic plant species to contaminants. We compared the relative sensitivity of the algae Selenestrum capricornutum and the floating vascular plant Lemna minor to 16 herbicides (atrazine, metribuzin, simazine, cyanazine, alachlor, metolachlor, chlorsulfuron, metsulfuron, triallate, EPTC, trifluralin, diquat, paraquat, dicamba, bromoxynil, and 2,4-D). The herbicides studied represented nine chemical classes and several modes of action and were chosen to represent major current uses in the United States. Both plant species were generally sensitive to the triazines (atrazine, metribuzin, simazine, and cyanazine), sulfonureas (metsulfuron and chlorsulfuron), pyridines (diquat and paraquat), dinitroaniline (trifluralin), and acetanilide (alachlor and metolachlor) herbicides. Neither plant species was uniformly more sensitive than the other across the broad range of herbicides tested. Lemna was more sensitive to the sulfonureas (metsulfuron and chlorsulfuron) and the pyridines (diquat and parequat) than Selenastrum. However Selenastrum was more sensitive than Lemna to one of two thiocarbamates (triallate) and one of the triazines (cyanazine). Neither species was sensitive to selective broadleaf herbicides including bromoxynil, EPTC, dicamba, or 2,4-D. Results were not always predictable in spite of obvious differences in herbicide modes of action and plant phylogeny. Major departures in sensitivity of Selenastrum occurred between chemicals within individual classes of the triazine, acetanilide, and thiocarbamate herbicides. Results indicate that neither

  13. Sensitivity of Phaseolus vulgaris cv. `CIAP 7247F' plants to Glufosinate ammonium herbicide in greenhouse

    Directory of Open Access Journals (Sweden)

    Idalmis Bermúdez-Caraballoso

    2014-01-01

    Full Text Available Genetic breeding in Phaseolus by genetic transformation requires an efficient selection system. The present investigation was aimed to determine the minimum lethal concentration of glufosinate-ammonium (Finale ® in beans plants cv. `CIAP 7247F' grown in greenhouse. Different concentrations of the herbicide were applied to the foliage of plants in acclimatization phase (20, 30 y 40 mg l-1 and the control. Results showed that the minimum lethal concentration in plants in acclimatization phase was 30 mg l-1. Results also demonstrated that is possible the use of the herbicide as a selective agent of beans transformants cv. `CIAP 7247F' carrying the bar gene. Keywords: genetic transformation, herbicide, selective agent, tissue culture

  14. Improved Gradation for Rain Garden of Low Impact Development

    Science.gov (United States)

    Lee, Sandra; Chang, Fu-Ming

    2016-04-01

    With rapid urban and economic development, living standard improves in urban areas but urban ecological environments deteriorate rapidly. Urban waterlogging and flooding have become a serious problem for urban water security. As urbanization continues, sustainability is the key to balance between urban development and healthy environment. Rain garden is recommended to be one of the best ways to reduce urban pollutants. It not only diminishes runoff flooding but also purify water in the urban area. The studies on rain gardens are mainly about how to incorporate rain garden to purify water quality, but lack of researches on runoff control. This project focuses on rain garden under Low Impact Development using indoor laboratory to test and quantify the water holding capacities of two different Taiwan indigenous rain garden plants, Taiwan Cyclosorus and Sour Grass. The results show that the water holding capacity of Sour Grass (10%-37%) is better than that of Taiwan Cyclosorus (6.8%-17.3%). The results could be a helpful reference for Low Impact Development in urban flood prevention and urban planning. Keywords: Low Impact Development; rain garden; indoor laboratory experiments; water holding capacity; porosity

  15. Eficácia e seletividade de herbicidas do grupo das imidazolinonas aplicados em pós-emergência de plantas daninhas monocotiledôneas na cultura do girassol CL Efficacy and selectivity of herbicides from the imidazolinone group applied in post-emergence of monocotyledon weeds on CL sunflower culture

    Directory of Open Access Journals (Sweden)

    A.C. Francischini

    2012-12-01

    objective of this study was to evaluate the efficacy and selectivity of herbicides of the imidazolinone group applied in post-emergence on monocotyledon weeds in Clearfield sunflower cultivation. Thus, two experiments were installed in the field. The treatments and their doses in gha-1 were: trifluralin (1800 applied at pre-emergence, fluazifop-p-butyl (187 and imazapic+imazapyr doses [36.75+12.25], [52.5+17.5], [12.25+36.75] and [17.5+52.5] applied at post-emergence, plus two controls without herbicide, one without weeding and the other with weeds. Control was evaluated for Eleusine indica, Brachiaria plantaginea, Lolium multiflorum, Digitaria insularis, Digitaria horizontalis and Cenchrus echinatus, Clearfield Sunflower phytotoxicity, stand and yield in kgha-1. The results obtained showed that the use of the Clearfield system proved to be a great option for areas with monocotyledon weed infestation, since it allows the application of acetolactate synthase (ALS - inhibiting herbicides achieving excellent weed control, without causing visual injury, and maintaining the original stand, without affecting crop yield.

  16. Efeitos da exploração madeireira de baixo impacto sobre uma comunidade de aves de sub-bosque na Floresta Nacional do Tapajós, Pará, Brasil Effects of low impact selective logging on an understory bird community in the Tapajós National Forest, Pará, Brazil

    Directory of Open Access Journals (Sweden)

    Luiza Magalli Pinto Henriques

    2008-01-01

    Full Text Available Este estudo compara a resposta de uma comunidade aves à exploração madeireira de baixo impacto através da distribuição das espécies em floresta controle e manejada ao longo de cinco anos com amostragem pré e pós-exploração. O procedimento de ordenação mostrou que a similaridade da comunidade de aves após a exploração madeireira foi menor que a similaridade entre as amostras do período de pré-exploração. Além disso, a ordem das abundâncias das 43 espécies mais comuns foi alterada entre o período anterior à exploração e 3 a 4 anos após a exploração na floresta manejada. A exploração afetou as taxas de captura de 20 espécies, diretamente ou através de uma interação com o tempo. Os insetívoros terrícolas e os insetívoros que seguem bandos mistos foram as guildas mais afetadas pela exploração madeireira. Ambas as guildas mostraram declínio, correlacionado com o tempo, em suas abundâncias em floresta manejada. Insetívoros seguidores de formigas e insetívoros arborícolas não apresentaram diferenças entre a floresta manejada e controle, apesar de algumas espécies dessas guildas terem apresentado efeitos relacionados ao manejo florestal, diretamente ou através de uma interação entre o tempo e o manejo. Frugívoros também não apresentaram efeitos significativos relacionados ao manejo florestal. Nectarívoros aumentaram tanto na floresta explorada como na floresta controle. Efeitos temporais de aumento ou declínio observados em guildas e em 12 espécies ocorreram tanto na floresta controle como na floresta explorada. Este resultado sugere que mudanças temporais na área explorada podem estar relacionadas à sucessão enquanto que mudanças temporais na floresta controle podem estar relacionados à exploração com intensidade de 40m³/ha de parcelas adjacentes.This study compares the avian response to low impact selective logging by comparing bird species distribution in control and cut forest during

  17. Rice Transcriptome Analysis to Identify Possible Herbicide Quinclorac Detoxification Genes

    Directory of Open Access Journals (Sweden)

    Wenying eXu

    2015-09-01

    Full Text Available Quinclorac is a highly selective auxin-type herbicide, and is widely used in the effective control of barnyard grass in paddy rice fields, improving the world’s rice yield. The herbicide mode of action of quinclorac has been proposed and hormone interactions affect quinclorac signaling. Because of widespread use, quinclorac may be transported outside rice fields with the drainage waters, leading to soil and water pollution and environmental health problems.In this study, we used 57K Affymetrix rice whole-genome array to identify quinclorac signaling response genes to study the molecular mechanisms of action and detoxification of quinclorac in rice plants. Overall, 637 probe sets were identified with differential expression levels under either 6 or 24 h of quinclorac treatment. Auxin-related genes such as GH3 and OsIAAs responded to quinclorac treatment. Gene Ontology analysis showed that genes of detoxification-related family genes were significantly enriched, including cytochrome P450, GST, UGT, and ABC and drug transporter genes. Moreover, real-time RT-PCR analysis showed that top candidate P450 families such as CYP81, CYP709C and CYP72A genes were universally induced by different herbicides. Some Arabidopsis genes for the same P450 family were up-regulated under quinclorac treatment.We conduct rice whole-genome GeneChip analysis and the first global identification of quinclorac response genes. This work may provide potential markers for detoxification of quinclorac and biomonitors of environmental chemical pollution.

  18. Linking fluorescence induction curve and biomass in herbicide screening.

    Science.gov (United States)

    Christensen, Martin G; Teicher, Harald B; Streibig, Jens C

    2003-12-01

    A suite of dose-response bioassays with white mustard (Sinapis alba L) and sugar beet (Beta vulgaris L) in the greenhouse and with three herbicides was used to analyse how the fluorescence induction curves (Kautsky curves) were affected by the herbicides. Bentazone, a photosystem II (PSII) inhibitor, completely blocked the normal fluorescence decay after the P-step. In contrast, fluorescence decay was still obvious for flurochloridone, a PDS inhibitor, and glyphosate, an EPSP inhibitor, which indicated that PSII inhibition was incomplete. From the numerous parameters that can be derived from OJIP-steps of the Kautsky curve the relative changes at the J-step [Fvj = (Fm - Fj)/Fm] was selected to be a common response parameter for the herbicides and yielded consistent dose-response relationships. Four hours after treatment, the response Fvj on the doses of bentazone and flurochloridone could be measured. For glyphosate, the changes of the Kautsky curve could similarly be detected 4 h after treatment in sugar beet, but only after 24 hs in S alba. The best prediction of biomass in relation to Fvj was found for bentazone. The experiments were conducted between May and August 2002 and showed that the ambient temperature and solar radiation in the greenhouse could affect dose-response relationships. If the Kautsky curve parameters should be used to predict the outcome of herbicide screening experiments in the greenhouse, where ambient radiation and temperature can only partly be controlled, it is imperative that the chosen fluorescence parameters can be used to predict accurately the resulting biomass used in classical bioassays.

  19. Leaf anatomy of cassava (Manihot esculenta Crantz. cv. IAC-12 after herbicides application to control weeds in Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel Valadão Silva

    2017-07-01

    Full Text Available Micro-morphological changes precede the appearance of visible damage after herbicide application and are essential in providing data for the safe recommendation in chemical management of weeds. Therefore, the aim of this research was to verify the anatomical changes of leaf tissue caused by application of herbicides in cassava (Manihot esculenta Crantz. cv. IAC-12. A greenhouse experiment was conducted with post-emergence herbicides treatments as follows: nicossulfuron (60 g a.i ha-1, fluazifop (250 g a.i ha-1, fomesafem (250 g a.i ha-1, metribuzin (480 g a.i ha-1, oxyfluorfen (720 g a.i ha-1 and the mixture fluazifop + fomesafen (200 + 250 g a.i ha-1, and an untreated control, respectively. The results obtained have allowed to affirm the cassava plants (cultivar IAC-12, exhibited changes in leaf anatomy in response to herbicide application even on cassava leaves without no visual toxicity symptoms. The products caused alterations both in tissue thickness as in tissue proportion in the leaf blade. For the fluazifop, a eudicotyledonous selective herbicide, changes were observed in tissue thickness and proportion of leaf blade, even without any visual toxicity detected. Cassava plants (IAC-12, showed structural changes in leaf anatomy in response to application of herbicides. The leaf anatomy of cassava cv. IAC-12, can be used to indicate the herbicide effect on cassava (Manihot esculenta Crantz.cv. IAC-12 plants.

  20. Discovery of Putative Herbicide Resistance Genes and Its Regulatory Network in Chickpea Using Transcriptome Sequencing

    Directory of Open Access Journals (Sweden)

    Mir A. Iquebal

    2017-06-01

    Full Text Available Background: Chickpea (Cicer arietinum L. contributes 75% of total pulse production. Being cheaper than animal protein, makes it important in dietary requirement of developing countries. Weed not only competes with chickpea resulting into drastic yield reduction but also creates problem of harboring fungi, bacterial diseases and insect pests. Chemical approach having new herbicide discovery has constraint of limited lead molecule options, statutory regulations and environmental clearance. Through genetic approach, transgenic herbicide tolerant crop has given successful result but led to serious concern over ecological safety thus non-transgenic approach like marker assisted selection is desirable. Since large variability in tolerance limit of herbicide already exists in chickpea varieties, thus the genes offering herbicide tolerance can be introgressed in variety improvement programme. Transcriptome studies can discover such associated key genes with herbicide tolerance in chickpea.Results: This is first transcriptomic studies of chickpea or even any legume crop using two herbicide susceptible and tolerant genotypes exposed to imidazoline (Imazethapyr. Approximately 90 million paired-end reads generated from four samples were processed and assembled into 30,803 contigs using reference based assembly. We report 6,310 differentially expressed genes (DEGs, of which 3,037 were regulated by 980 miRNAs, 1,528 transcription factors associated with 897 DEGs, 47 Hub proteins, 3,540 putative Simple Sequence Repeat-Functional Domain Marker (SSR-FDM, 13,778 genic Single Nucleotide Polymorphism (SNP putative markers and 1,174 Indels. Randomly selected 20 DEGs were validated using qPCR. Pathway analysis suggested that xenobiotic degradation related gene, glutathione S-transferase (GST were only up-regulated in presence of herbicide. Down-regulation of DNA replication genes and up-regulation of abscisic acid pathway genes were observed. Study further reveals

  1. In-field frequencies and characteristics of oilseed rape with double herbicide resistance.

    Science.gov (United States)

    Dietz-Pfeilstetter, Antje; Zwerger, Peter

    2009-01-01

    When growing different transgenic herbicide-resistant oilseed rape cultivars side by side, seeds with multiple herbicide resistance can arise, possibly causing problems for the management of volunteer plants. Large-scale field experiments were performed in the years 1999/2000 and 2000/2001 in order to investigate the frequencies and the consequences of the transfer of herbicide resistance genes from transgenic oilseed rape to cultivars grown on neighboring agricultural fields. Transgenic oilseed rape with resistance to glufosinate-ammonium (LibertyLink, LL) and with glyphosate resistance (RoundupReady, RR), respectively, was sown in adjacent 0.5 ha plots, surrounded by about 8 ha non-transgenic oilseed rape. The plots and the field were either in direct contact (0.5 m gap width) or they were separated by 10 m of fallow land. Seed samples taken during harvest in the transgenic plots at different distances were investigated for progeny with resistance to the respective other herbicide. It was found that outcrossing frequencies were reduced to different extents by a 10 m isolation distance. In addition to pollen-mediated transgene flow as a result of outcrossing, we found considerable seed-mediated gene flow by adventitious dispersal of transgenic seeds through the harvesting machine. Volunteer plants with double herbicide resistance emerging in the transgenic plots after harvest were selected by suitable applications of the complementary herbicides Basta and Roundup Ultra. In both years, double-resistant volunteers were largely restricted to the inner edges of the plots. Expression analysis under controlled laboratory conditions of double-resistant plants generated by manual crosses revealed stability of transgene expression even at elevated temperatures. Greenhouse tests with double-resistant oilseed rape plants gave no indication that the sensitivity to a range of different herbicides is changed as compared to non-transgenic oilseed rape.

  2. Multiobjective optimization of low impact development stormwater controls

    Science.gov (United States)

    Eckart, Kyle; McPhee, Zach; Bolisetti, Tirupati

    2018-07-01

    Green infrastructure such as Low Impact Development (LID) controls are being employed to manage the urban stormwater and restore the predevelopment hydrological conditions besides improving the stormwater runoff water quality. Since runoff generation and infiltration processes are nonlinear, there is a need for identifying optimal combination of LID controls. A coupled optimization-simulation model was developed by linking the U.S. EPA Stormwater Management Model (SWMM) to the Borg Multiobjective Evolutionary Algorithm (Borg MOEA). The coupled model is capable of performing multiobjective optimization which uses SWMM simulations as a tool to evaluate potential solutions to the optimization problem. The optimization-simulation tool was used to evaluate low impact development (LID) stormwater controls. A SWMM model was developed, calibrated, and validated for a sewershed in Windsor, Ontario and LID stormwater controls were tested for three different return periods. LID implementation strategies were optimized using the optimization-simulation model for five different implementation scenarios for each of the three storm events with the objectives of minimizing peak flow in the stormsewers, reducing total runoff, and minimizing cost. For the sewershed in Windsor, Ontario, the peak run off and total volume of the runoff were found to reduce by 13% and 29%, respectively.

  3. Potential organic herbicides for squash production: Pelargonic acid herbicides AXXE (registered trademark) and Scythe (registered trademark)

    Science.gov (United States)

    Organic squash (Cucurbita pepo L.) producers need appropriate herbicides that can effectively provide season- long weed control. Research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determine the impact of potential organic herbicides on weed control efficacy, crop injury, and y...

  4. Genetically Modified Herbicide-Tolerant Crops, Weeds, and Herbicides: Overview and Impact

    Science.gov (United States)

    Bonny, Sylvie

    2016-01-01

    Genetically modified (GM) crops have been and continue to be a subject of controversy despite their rapid adoption by farmers where approved. For the last two decades, an important matter of debate has been their impact on pesticide use, particularly for herbicide-tolerant (HT) crops. Some claim that these crops bring about a decrease in herbicide use, while others claim the opposite. In fact, since 1996, most cultivated GMOs have been GMHT crops, which involve the use of an associated herbicide, generally glyphosate. In their very first years of adoption, HT crops often led to some decrease in herbicide use. However, the repetition of glyphosate-tolerant crops and of glyphosate only applications in the same fields without sufficient alternation and herbicide diversity has contributed to the appearance of glyphosate-resistant weeds. These weeds have resulted in a rise in the use of glyphosate and other herbicides. This article explores this situation and the impacts of herbicide-resistant weeds, using an interdisciplinary approach and drawing on recent data. The paper analyzes the spread of GMHT crops worldwide and their consequences on herbicide use in the USA in particular. It then addresses the global development of glyphosate-resistant weeds and their impact, particularly focusing on the USA. Finally, the last section explores how industry, farmers, and weed scientists are coping with the spread of resistant weeds. The concluding comments deal more widely with trends in GM crops.

  5. Herbicide resistance and biodiversity: agronomic and environmental aspects of genetically modified herbicide-resistant plants.

    Science.gov (United States)

    Schütte, Gesine; Eckerstorfer, Michael; Rastelli, Valentina; Reichenbecher, Wolfram; Restrepo-Vassalli, Sara; Ruohonen-Lehto, Marja; Saucy, Anne-Gabrielle Wuest; Mertens, Martha

    2017-01-01

    Farmland biodiversity is an important characteristic when assessing sustainability of agricultural practices and is of major international concern. Scientific data indicate that agricultural intensification and pesticide use are among the main drivers of biodiversity loss. The analysed data and experiences do not support statements that herbicide-resistant crops provide consistently better yields than conventional crops or reduce herbicide amounts. They rather show that the adoption of herbicide-resistant crops impacts agronomy, agricultural practice, and weed management and contributes to biodiversity loss in several ways: (i) many studies show that glyphosate-based herbicides, which were commonly regarded as less harmful, are toxic to a range of aquatic organisms and adversely affect the soil and intestinal microflora and plant disease resistance; the increased use of 2,4-D or dicamba, linked to new herbicide-resistant crops, causes special concerns. (ii) The adoption of herbicide-resistant crops has reduced crop rotation and favoured weed management that is solely based on the use of herbicides. (iii) Continuous herbicide resistance cropping and the intensive use of glyphosate over the last 20 years have led to the appearance of at least 34 glyphosate-resistant weed species worldwide. Although recommended for many years, farmers did not counter resistance development in weeds by integrated weed management, but continued to rely on herbicides as sole measure. Despite occurrence of widespread resistance in weeds to other herbicides, industry rather develops transgenic crops with additional herbicide resistance genes. (iv) Agricultural management based on broad-spectrum herbicides as in herbicide-resistant crops further decreases diversity and abundance of wild plants and impacts arthropod fauna and other farmland animals. Taken together, adverse impacts of herbicide-resistant crops on biodiversity, when widely adopted, should be expected and are indeed very hard

  6. Manual herbicide application methods for managing vegetation in Appalachian hardwood forests

    Science.gov (United States)

    Jeffrey D. Kochenderfer; James N. Kochenderfer; Gary W. Miller

    2012-01-01

    Four manual herbicide application methods are described for use in Appalachian hardwood forests. Stem injection, basal spray, cut-stump, and foliar spray techniques can be used to control interfering vegetation and promote the development of desirable reproduction and valuable crop trees in hardwood forests. Guidelines are presented to help the user select the...

  7. Biomass, Leaf Area, and Resource Availability of Kudzu Dominated Plant Communities Following Herbicide Treatment

    Energy Technology Data Exchange (ETDEWEB)

    L.T. Rader

    2001-10-01

    Kudzu is an exotic vine that threatens the forests of the southern U.S. Five herbicides were tested with regard to their efficacy in controlling kudzu, community recover was monitored, and interactions with planted pines were studied. The sites selected were old farm sites dominated by kudzu.These were burned following herbicide treatment. The herbicides included triclopyr, clopyralid, metsulfuron, tebuthiuron, and picloram plus 2,4-D. Pine seedlings were planted the following year. Regression equations were developed for predicting biomass and leaf area. Four distinct plant communities resulted from the treatments. The untreated check continued to be kudzu dominated. Blackberry dominated the clopyradid treatment. Metsulfron, trychlopyr and picloram treated sites resulted in herbaceous dominated communities. The tebuthiuron treatment maintained all vegetation low.

  8. BELVEDERE® Extra – a new high performance- herbicide in beets

    Directory of Open Access Journals (Sweden)

    Donati, Alexandra

    2014-03-01

    Full Text Available Common lambsquarters, cleavers, ladysthumb and wild buckwheat, chamomile, mercury, foolsparsleey and volunteer rapes are only some of the most important weeds in fooder and sugar beets. For the control of classical weed societies farmers can fall back on a limited number of active ingredients. Generally, Phenmedipham (PMP, Desmedipham (DMP and Ethofumesate are the basis of a spray sequence. They are complemented with other active ingredients depending on the specific weed situation. The newly formulated BELVEDERE® Extra combines the three mentioned active ingredients in an optimal ratio. Hence, the herbicide covers a very broad weed spectrum with an excellent efficacy on Common lambsquarters, cleavers, ladysthumb and wild buckwheat. BELVEDERE® EXTRA is a liquid, selective, and systemic herbicide. It is formulated as suspoemulsion so that a high efficacy is achieved while preserving a very good selectivity. The product allows for flexible control of leaf activity as an additive (e.g. OLEO FC is appended. Ethofumesate, which is mainly effective via the roots of the plant, belongs to a different HRAC group than Phenmedipham and Desmedipham. The high concentration of 200 g/L Ethofumesate leads to an effective resistance management especially regarding Fathen and other important weeds. Since 23rd of September 2013 BELVEDERE® extra is registered for post emergence splitting application (3 applications against annual dicotyledonous weeds. The maximum application rate per treatment is 1,3 L/ha. In combination with GOLTIX® TITAN® (Metamitron + Quinmerac or Goltix® Gold (Metamitron the weed spectrum is broadened. Basically, a timely application whose application rates are adapted to the location is essential for a good efficacy of beet herbicides.

  9. Potential environmental impacts associated with large-scale herbicide-tolerant GM oilseed rape crops

    Directory of Open Access Journals (Sweden)

    Fellous Marc

    2004-07-01

    Full Text Available The Biomolecular Engineering Commission considers that the knowledge acquired in the last three years has provided significant information in reply to the points raised in its review dated 16 February 2001. The Commission has studied the potential environmental impacts associated with large-scale herbicidetolerantGMoilseed rape crops, making a distinction between direct and indirect impacts. Direct impacts stem from the intrinsic properties of herbicide-tolerant GM oilseed rape crops whereas indirect impacts result from practices associated with the farming of these crops. The Commission considers that, in the absence of the use of the herbicide in question in and outside of farmed land, there is no direct environmental risk (development of invasive crops per se associated with the presence of a herbicide-tolerance gene in oilseed rape (or related species. Nevertheless, since the interest of these tolerant crops lies in the use of the herbicide in question, indirect effects, to varying extents, have been identified and must be taken into account: the use of the herbicide in question, applied to agricultural fields containing the herbicide-tolerant crop could lead to an increase in oilseed rape volunteer populations in crop rotations; the selective pressure exerted by non-specific herbicides (to which the crops have been rendered tolerant may be very high in cases of continuous and uncontrolled use of these herbicides, and may result in the persistence of rare events such as the reproduction of fertile interspecies hybrids; the change to the range of herbicides used should be conveyed by more effective weed control and, like any change in farming practices, induce indirect effects on the agri-ecosystem, particularly in terms of changes to weeds and the associated animal life. Accordingly, the Biomolecular Engineering Commission recommends a global approach in terms of the large-scale farming of herbicide-tolerant crops that: accounts for the

  10. [Advances in low impact development technology for urban stormwater management].

    Science.gov (United States)

    Liu, Wen; Chen, Wei-ping; Peng, Chi

    2015-06-01

    Low impact development ( LID), as an innovative technology for stormwater management, is effective to mitigate urban flooding and to detain pollutants. This paper systemically introduced the LID technology system, and summarized the reduction effects of three typical LID facilities (i.e. , bio-retention, green roof and permeable pavement) on stormwater runoff and main pollutants in recent literature, as well as research outcomes and experiences of LID technology on model simulation, cost-benefit analysis and management system. On this basis, we analyzed the problems and limitations of current LID technology studies. Finally, some suggestions about future research directions, appropriate design and scientific management were put forth. This work intended to provide scientific basis and suggestions for widespread use and standard setting of LID technology in China by referencing overseas studies.

  11. Herbicide Safeners Decrease Sensitivity to Herbicides Inhibiting Acetolactate-Synthase and Likely Activate Non-Target-Site-Based Resistance Pathways in the Major Grass Weed Lolium sp. (Rye-Grass

    Directory of Open Access Journals (Sweden)

    Arnaud Duhoux

    2017-08-01

    Full Text Available Herbicides are currently pivotal to control weeds and sustain food security. Herbicides must efficiently kill weeds while being as harmless as possible for crops, even crops taxonomically close to weeds. To increase their selectivity toward crops, some herbicides are sprayed in association with safeners that are bioactive compounds exacerbating herbicide-degrading pathways reputedly specifically in crops. However, exacerbated herbicide metabolism is also a key mechanism underlying evolved non-target-site-based resistance to herbicides (NTSR in weeds. This raised the issue of a possible role of safeners on NTSR evolution in weeds. We investigated a possible effect of the respective field rates of the two broadly used safeners cloquintocet-mexyl and mefenpyr-diethyl on the sensitivity of the troublesome global weed Lolium sp. (rye-grass to the major herbicides inhibiting acetolactate-synthase (ALS pyroxsulam and iodosulfuron + mesosulfuron, respectively. Three Lolium sp. populations were studied in three series of experiments. The first experiment series compared the frequencies of plants surviving application of each herbicide alone or in association with its safener. Safener co-application caused a net increase ranging from 5.0 to 46.5% in the frequency of plants surviving the field rate of their associated herbicide. In a second series of experiments, safener effect was assessed on individual plant sensitivity using vegetative propagation. A reduction in sensitivity to pyroxsulam and to iodosulfuron + mesosulfuron was observed for 44.4 and 11.1% of the plants in co-treatment with cloquintocet-mexyl and mefenpyr-diethyl, respectively. A third series of experiments investigated safener effect on the expression level of 19 Lolium sp. NTSR marker genes. Safeners showed an enhancing effect on the expression level of 10 genes. Overall, we demonstrated that cloquintocet-mexyl and mefenpyr-diethyl both reduced the sensitivity of Lolium sp. to their

  12. Herbicide Safeners Decrease Sensitivity to Herbicides Inhibiting Acetolactate-Synthase and Likely Activate Non-Target-Site-Based Resistance Pathways in the Major Grass Weed Lolium sp. (Rye-Grass).

    Science.gov (United States)

    Duhoux, Arnaud; Pernin, Fanny; Desserre, Diane; Délye, Christophe

    2017-01-01

    Herbicides are currently pivotal to control weeds and sustain food security. Herbicides must efficiently kill weeds while being as harmless as possible for crops, even crops taxonomically close to weeds. To increase their selectivity toward crops, some herbicides are sprayed in association with safeners that are bioactive compounds exacerbating herbicide-degrading pathways reputedly specifically in crops. However, exacerbated herbicide metabolism is also a key mechanism underlying evolved non-target-site-based resistance to herbicides (NTSR) in weeds. This raised the issue of a possible role of safeners on NTSR evolution in weeds. We investigated a possible effect of the respective field rates of the two broadly used safeners cloquintocet-mexyl and mefenpyr-diethyl on the sensitivity of the troublesome global weed Lolium sp. (rye-grass) to the major herbicides inhibiting acetolactate-synthase (ALS) pyroxsulam and iodosulfuron + mesosulfuron, respectively. Three Lolium sp. populations were studied in three series of experiments. The first experiment series compared the frequencies of plants surviving application of each herbicide alone or in association with its safener. Safener co-application caused a net increase ranging from 5.0 to 46.5% in the frequency of plants surviving the field rate of their associated herbicide. In a second series of experiments, safener effect was assessed on individual plant sensitivity using vegetative propagation. A reduction in sensitivity to pyroxsulam and to iodosulfuron + mesosulfuron was observed for 44.4 and 11.1% of the plants in co-treatment with cloquintocet-mexyl and mefenpyr-diethyl, respectively. A third series of experiments investigated safener effect on the expression level of 19 Lolium sp. NTSR marker genes. Safeners showed an enhancing effect on the expression level of 10 genes. Overall, we demonstrated that cloquintocet-mexyl and mefenpyr-diethyl both reduced the sensitivity of Lolium sp. to their associated ALS

  13. The benefits of herbicide-resistant crops.

    Science.gov (United States)

    Green, Jerry M

    2012-10-01

    Since 1996, genetically modified herbicide-resistant crops, primarily glyphosate-resistant soybean, corn, cotton and canola, have helped to revolutionize weed management and have become an important tool in crop production practices. Glyphosate-resistant crops have enabled the implementation of weed management practices that have improved yield and profitability while better protecting the environment. Growers have recognized their benefits and have made glyphosate-resistant crops the most rapidly adopted technology in the history of agriculture. Weed management systems with glyphosate-resistant crops have often relied on glyphosate alone, have been easy to use and have been effective, economical and more environmentally friendly than the systems they have replaced. Glyphosate has worked extremely well in controlling weeds in glyphosate-resistant crops for more than a decade, but some key weeds have evolved resistance, and using glyphosate alone has proved unsustainable. Now, growers need to renew their weed management practices and use glyphosate with other cultural, mechanical and herbicide options in integrated systems. New multiple-herbicide-resistant crops with resistance to glyphosate and other herbicides will expand the utility of existing herbicide technologies and will be an important component of future weed management systems that help to sustain the current benefits of high-efficiency and high-production agriculture. Copyright © 2012 Society of Chemical Industry.

  14. studies on transition metal complexes of herbicidal compounds. ii

    African Journals Online (AJOL)

    a

    derivative of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine, atrazine (ATZ) --- a well known herbicide has ... development while the other is the metal ion associated degradation or deactivation of the herbicides .... Colour M.p./decomp.

  15. Removal of triazine herbicides from freshwater systems using photosynthetic microorganisms

    International Nuclear Information System (INIS)

    Gonzalez-Barreiro, O.; Rioboo, C.; Herrero, C.; Cid, A.

    2006-01-01

    The uptake of the triazine herbicides, atrazine and terbutryn, was determined for two freshwater photosynthetic microorganisms, the green microalga Chlorella vulgaris and the cyanobacterium Synechococcus elongatus. An extremely rapid uptake of both pesticides was recorded, although uptake rate was lower for the cyanobacterium, mainly for atrazine. Other parameters related to the herbicide bioconcentration capacity of these microorganisms were also studied. Growth rate, biomass, and cell viability in cultures containing herbicide were clearly affected by herbicide uptake. Herbicide toxicity and microalgae sensitivity were used to determine the effectiveness of the bioconcentration process and the stability of herbicide removal. C. vulgaris showed higher bioconcentration capability for these two triazine herbicides than S. elongatus, especially with regard to terbutryn. This study supports the usefulness of such microorganisms, as a bioremediation technique in freshwater systems polluted with triazine herbicides

  16. Removal of triazine herbicides from freshwater systems using photosynthetic microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Barreiro, O. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Rioboo, C. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Herrero, C. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Cid, A. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain)]. E-mail: cid@udc.es

    2006-11-15

    The uptake of the triazine herbicides, atrazine and terbutryn, was determined for two freshwater photosynthetic microorganisms, the green microalga Chlorella vulgaris and the cyanobacterium Synechococcus elongatus. An extremely rapid uptake of both pesticides was recorded, although uptake rate was lower for the cyanobacterium, mainly for atrazine. Other parameters related to the herbicide bioconcentration capacity of these microorganisms were also studied. Growth rate, biomass, and cell viability in cultures containing herbicide were clearly affected by herbicide uptake. Herbicide toxicity and microalgae sensitivity were used to determine the effectiveness of the bioconcentration process and the stability of herbicide removal. C. vulgaris showed higher bioconcentration capability for these two triazine herbicides than S. elongatus, especially with regard to terbutryn. This study supports the usefulness of such microorganisms, as a bioremediation technique in freshwater systems polluted with triazine herbicides.

  17. Weed control in distress – can all weeds still be controlled with herbicides in future?

    Directory of Open Access Journals (Sweden)

    Drobny, Hans G.

    2016-02-01

    Full Text Available The introduction and availability of highly active and selective herbicides in all important field crops, in the last decades, enabled the simplification and money saving in crop rotations and agronomic measures. This resulted in respective specialized and adapted weed populations, and consequently an increasing selection of resistant populations. Since the introduction of the ALS-inhibitors (starting 1985 and the 4-HPPD-inhibitors (2001, no new MoA-Classes were registered, and there are none in the registration process. Several established herbicides were not registered or re-registered in the EU, or were severely restricted in their application. The cost and the risk to develop and register a new selective herbicide in the EU are hardly justified, in relation to their market potential. The only solution on problem fields, with resistant populations, is to change the agronomic practices, like crop rotation, soil tillage, seeding time, etc., as a precautionary principle also on still „normal“ fields. The different advising institutions have to integrate these aspects into their recommendations, besides the proper herbicide management.

  18. Discovery of new herbicide modes of action with natural phytotoxins

    Science.gov (United States)

    About 20 modes of action (MOAs) are utilized by commercial herbicides, and almost 30 years have passed since the last new MOA was introduced. Rapidly increasing evolution of resistance to herbicides with these MOAs has greatly increased the need for herbicides with new MOAs. Combinatorial chemistry ...

  19. Preemergence herbicides on weed control in elephant grass pasture

    Directory of Open Access Journals (Sweden)

    Alexandre Magno Brighenti

    Full Text Available ABSTRACT Elephant grass (Pennisetum purpureum Schum. is an important forage crop that has been proposed as a potential feedstock for bioenergy production. However, weed interference is a major factor limiting elephant grass production. Field experiments were conducted in 2014 and 2015 to evaluate preemergence herbicides for selective weed control in an elephant grass pasture. Herbicide treatments included atrazine + S-metolachlor, atrazine + simazine, ametryn, ethoxysulfuron, S-metolachlor, diuron + hexazinone, sulfentrazone, imazethapyr, and atrazine at label use rates. Weedy and weed-free treatments were included. Atrazine + S-metolachlor, atrazine + simazine, ametryn, ethoxysulfuron, S-metolachlor, sulfentrazone, and atrazine did not cause phytotoxicity on elephantgrass 35 days after treatment (DAT. However, diuron + hexazinone and imazethapyr were the most phytotoxic on elephantgrass, resulting in 81 and 70% phytotoxicity in 2014, and 7 and 6% phytotoxicity in 2015 respectively 35 DAT. All treatments provided effective weed control (>81% with the exception of ethoxysulfuron (0 and 11% in 2014 and 2015, respectively, and atrazine (59% in 2014. These results show that atrazine + S-metolachlor, atrazine + simazine, ametryn, ethoxysulfuron, S-metolachlor, sulfentrazone, and atrazine were selectives when applied in preemergence in elephant grass pasture.

  20. Retrofitting the Low Impact Development Practices into Developed Urban areas Including Barriers and Potential Solution

    Science.gov (United States)

    Shafique, Muhammad; Kim, Reeho

    2017-06-01

    Low impact development (LID)/green infrastructure (GI) practices have been identified as the sustainable practices of managing the stormwater in urban areas. Due to the increasing population, most of the cities are more developing which results in the change of natural area into impervious areas (roads, buildings etc.). Moreover, urbanization and climate change are causing many water-related problems and making over cities unsafe and insecure. Under these circumstances, there is a need to introduce new stormwater management practices into developed cities to reduce the adverse impacts of urbanization. For this purpose, retrofitting low impact development practices demands more attention to reduce these water-related problems and trying to make our cities sustainable. In developed areas, there is a little space is available for the retrofitting of LID practices for the stormwater management. Therefore, the selection of an appropriate place to retrofitting LID practices needs more concern. This paper describes the successfully applied retrofitting LID practices around the globe. It also includes the process of applying retrofitting LID practices at the suitable place with the suitable combination. Optimal places for the retrofitting of different LID practices are also mentioned. This paper also highlights the barriers and potential solutions of retrofitting LID practices in urban areas.

  1. Retrofitting the Low Impact Development Practices into Developed Urban areas Including Barriers and Potential Solution

    Directory of Open Access Journals (Sweden)

    Shafique Muhammad

    2017-06-01

    Full Text Available Low impact development (LID/green infrastructure (GI practices have been identified as the sustainable practices of managing the stormwater in urban areas. Due to the increasing population, most of the cities are more developing which results in the change of natural area into impervious areas (roads, buildings etc.. Moreover, urbanization and climate change are causing many water-related problems and making over cities unsafe and insecure. Under these circumstances, there is a need to introduce new stormwater management practices into developed cities to reduce the adverse impacts of urbanization. For this purpose, retrofitting low impact development practices demands more attention to reduce these water-related problems and trying to make our cities sustainable. In developed areas, there is a little space is available for the retrofitting of LID practices for the stormwater management. Therefore, the selection of an appropriate place to retrofitting LID practices needs more concern. This paper describes the successfully applied retrofitting LID practices around the globe. It also includes the process of applying retrofitting LID practices at the suitable place with the suitable combination. Optimal places for the retrofitting of different LID practices are also mentioned. This paper also highlights the barriers and potential solutions of retrofitting LID practices in urban areas.

  2. Surface plasmon resonance application for herbicide detection

    Science.gov (United States)

    Chegel, Vladimir I.; Shirshov, Yuri M.; Piletskaya, Elena V.; Piletsky, Sergey A.

    1998-01-01

    The optoelectronic biosensor, based on Surface Plasmon Resonance (SPR) for detection of photosynthesis-inhibiting herbicides in aqueous solutions is presented. The pesticide capability to replace plastoquinone from its complex with D1 protein is used for the detection. This replacement reaction results in the changes of the optical characteristics of protein layer, immobilized on the gold surface. Monitoring of these changes with SPR-technique permit to determine 0.1 - 5.0 mkg/ml herbicide in solution within one hour.

  3. Herbicide Orange Site Characterization Study, Eglin AFB

    Science.gov (United States)

    1987-01-01

    F THIS PAGE Availabilit o this r is sp f o.n" the reverse of fo cove* . - .’.r. 717 CSAT CO ES ’SU JEC TE MS Coninu onrevrseif ece~ar an idntiy b...of Hardstand 7 and Surface Water Drainages ......... 4 3 Hardstand 7 Herbicide Oran&e Storage Locations .............. 5 4 Concentrations (in ppb) of...insoluble in water . The formula contained an approximate 50/50 mixture of the herbicides 2,4-dichlorophenoxyacetic acid (2,4,-D) and 2,4,5

  4. Response of Transplanted Aman Rice Varieties to Herbicides in Strip-Tilled Non-Puddled Soil

    Directory of Open Access Journals (Sweden)

    Taslima Zahan1

    2017-12-01

    Full Text Available BACKGROUND: Sensitivity of crop cultivars may vary to commonly used herbicides resulting in potential yield loss and reduce farm profit. Transplanting of rice seedlings in strip-tilled non-puddled field is a new practice for which herbicide tolerant varieties need to select. Therefore, a study was executed at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh during 2013 to evaluate the response of some popular transplanted aman rice varieties to different herbicides at their recommended rate and to select most tolerant aman rice variety or varieties for strip-tilled non-puddled transplanting. METHODOLOGY: Twelve aman rice varieties (BR11, BRRI dhan33, BRRI dhan39, BRRI dhan44, BRRI dhan46, BRRI dhan49, BRRI dhan51, BRRI dhan52, BRRI dhan56, BRRI dhan57, BRRI hybrid dhan-4 and BINA dhan7 were examined in the study against six herbicides (2 pre-emergence: pyrazosulfuron-ethyl and butachlor; 1 early post-emergence: orthosulfamuron and 3 late post-emergence: acetochlor + bensulfuron methyl, butachlor + propanil and 2,4-D amine along with one untreated manually weed-free control. KEY FINDINGS: The study revealed that aman rice varieties responded differentially to different herbicides. All rice varieties performed better in pyrazosulfuron-ethyl treated plots relative to the other herbicide treated plots and even than the control plots. Pyrazosulfuron-ethyl increased grain yield of all aman rice varieties by 0.6-32.6% over control and butachlor + propanil provided increased grain yield in all rice varieties by 2.0-25.5% except BRRI hybrid dhan-4. The study also disclosed that BRRI dhan57 and BRRI hybrid dhan-4 gone through the yield loss by application of 2,4-D amine and BRRI dhan56 by application of butachlor and orthosulfamuron. Moreover, acetochlor + bensulfuron methyl produced shorter plants and caused yield loss by 7.8-27.1% in all aman rice varieties compared to the control and BRRI dhan39 was the most susceptible

  5. Weed management through herbicide application in direct-seeded rice and yield modeling by artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, D.; Singh, U.P.; Ray, K.; Das, A.

    2016-11-01

    In direct seeded rice (DSR) cultivation, weed is the major constraint mainly due to absence of puddling in field. The yield loss due to weed interference is huge, may be up to 100%. In this perspective, the present experiment was conducted to study the efficacy of selected herbicides, and to predict the rice yield using artificial neural network (ANN) models. The dry weight and density of weeds were recorded at different growth stages and consequently herbicidal efficacy was evaluated. Experimental results revealed that pre-emergence (PRE) herbicide effectively controlled the germination of grassy weeds. Application bispyribac-sodium as post-emergence (POST) following PRE herbicides (clomazone or pendimethalin) or as tank-mixture with clomazone effectively reduced the density and biomass accumulation of diverse weed flora in DSR. Herbicidal treatments improved the plant height, yield attributes and grain yield (2.7 to 5.5 times) over weedy check. The sensitivity of the best ANN model clearly depicts that the weed control index (WCI) of herbicides was most important than their weed control efficiency (WCE). Besides, the early control of weeds is a better prescription to improve rice yield. Differences in sensitivity values of WCI and WCE across the crop growth stages also suggest that at 15, 30 and 60 days after sowing, herbicides most effectively controlled sedges, broad leaves and grasses, respectively. Based on the grain yield and herbicidal WCE, it can be concluded that the combined application of pendimethalin or clomazone as PRE followed by bispyribac-sodium as POST or tank-mixture of clomazone + bispyribac sodium can effectively control different weed flushes throughout the crop growth period in DSR. (Author)

  6. Using fluorescent dyes as proxies to study herbicide removal by sorption in buffer zones.

    Science.gov (United States)

    Dollinger, Jeanne; Dagès, Cécile; Voltz, Marc

    2017-04-01

    The performance of buffer zones for removing pesticides from runoff water varies greatly according to landscape settings, hydraulic regime, and system design. Evaluating the performance of buffers for a range of pesticides and environmental conditions can be very expensive. Recent studies suggested that the fluorescent dyes uranine and sulforhodamine B could be used as cost-effective surrogates of herbicides to evaluate buffer performance. However, while transformation mechanisms in buffers have been extensively documented, sorption processes of both dyes have rarely been investigated. In this study, we measured the adsorption, desorption, and kinetic sorption coefficients of uranine and sulforhodamine B for a diverse range of buffer zone materials (soils, litters, plants) and compared the adsorption coefficients (Kd) to those of selected herbicides. We also compared the global sorption capacity of 6 ditches, characterized by varying proportions of the aforementioned materials, between both dyes and a set of four herbicides using the sorption-induced pesticide retention indicator (SPRI). We found that both the individual Kd of uranine for the diverse buffer materials and the global sorption capacity of the ditches are equivalent to those of the herbicides diuron, isoproturon, and metolachlor. The Kd of sulforhodamine B on plants and soils are equivalent to those of glyphosate, and the global sorption capacities of the ditches are equivalent for both molecules. Hence, we demonstrate for the first time that uranine can be used as a proxy of moderately hydrophobic herbicides to evaluate the performance of buffer systems, whereas sulforhodamine B can serve as a proxy for more strongly sorbing herbicides.

  7. Low-Impact Exploration for Gold in the Scottish Caledonides.

    Science.gov (United States)

    Rice, Samuel; Cuthbert, Simon; Hursthouse, Andrew; Broetto, Gabriele

    2017-04-01

    The Caledonian orogenic belt of the northern British Isles hosts some significant gold deposits. However, gold mineralization in the region is underexplored. Some of the most prospective areas identified by rich alluvial gold anomalies are environmentally and culturally sensitive. Traditional mineral exploration methods can have a range of negative environmental, social and economic impacts. The regional tourism economy is dependent on outdoor activities, landscape quality, wildlife and industrial heritage and has the potential to be disrupted by mineral resource developments. Low-cost, low-impact exploration strategies are therefore, key to sustainably developing the mineral resource potential. Research currently in progress in part of the Scottish Caledonides aims to develop protocols for more sustainable exploration. We are using a range of geoscience techniques to characterize the mineral system, improve exploration targeting and reduce negative impacts. To do this we targeted an area with a large preexisting dataset (e.g. stream sediment geochemistry, geomorphology, structural geology, petrology, geophysics, mine data) that can be synthesized and analyzed in a GIS. Part of the work aims to develop and test a model for gold dispersion in the surface environment that accounts for climatic and anthropogenic influences in order to locate bedrock sources. This multidisciplinary approach aims to reduce the target areas for subsequent exploration activities such as soil sampling, excavation and drilling.

  8. Methods for Rapid Screening in Woody Plant Herbicide Development

    Directory of Open Access Journals (Sweden)

    William Stanley

    2014-07-01

    Full Text Available Methods for woody plant herbicide screening were assayed with the goal of reducing resources and time required to conduct preliminary screenings for new products. Rapid screening methods tested included greenhouse seedling screening, germinal screening, and seed screening. Triclopyr and eight experimental herbicides from Dow AgroSciences (DAS 313, 402, 534, 548, 602, 729, 779, and 896 were tested on black locust, loblolly pine, red maple, sweetgum, and water oak. Screening results detected differences in herbicide and species in all experiments in much less time (days to weeks than traditional field screenings and consumed significantly less resources (<500 mg acid equivalent per herbicide per screening. Using regression analysis, various rapid screening methods were linked into a system capable of rapidly and inexpensively assessing herbicide efficacy and spectrum of activity. Implementation of such a system could streamline early-stage herbicide development leading to field trials, potentially freeing resources for use in development of beneficial new herbicide products.

  9. A Rapid and Simple Bioassay Method for Herbicide Detection

    Directory of Open Access Journals (Sweden)

    Xiu-Qing Li

    2008-01-01

    Full Text Available Chlamydomonas reinhardtii, a unicellular green alga, has been used in bioassay detection of a variety of toxic compounds such as pesticides and toxic metals, but mainly using liquid culture systems. In this study, an algal lawn--agar system for semi-quantitative bioassay of herbicidal activities has been developed. Sixteen different herbicides belonging to 11 different categories were applied to paper disks and placed on green alga lawns in Petri dishes. Presence of herbicide activities was indicated by clearing zones around the paper disks on the lawn 2-3 days after application. The different groups of herbicides induced clearing zones of variable size that depended on the amount, mode of action, and chemical properties of the herbicides applied to the paper disks. This simple, paper-disk-algal system may be used to detect the presence of herbicides in water samples and act as a quick and inexpensive semi-quantitative screening for assessing herbicide contamination.

  10. Effect of herbicides on microbiological properties of soil

    Directory of Open Access Journals (Sweden)

    Milošević Nada A.

    2002-01-01

    Full Text Available Microorganisms decompose herbicides and they may serve as bioindicators of soil changes following herbicide application. Certain microbial species may be used as bioherbicides. This study has shown that Azotobacter is most sensitive to herbicide application; it is, therefore, a reliable indicator of the biological value of soil. The numbers of this group of nitrogen-fixing bacteria decrease considerably in the period of 7-14 days after herbicide application. Simultaneously, the numbers of Actinomycetes and less so of fungi increase, indicating that these microorganisms use herbicides as sources of biogenous elements. Rate of herbicidal decomposition depends on the properties of the preparation applied herbicide dose as well as on the physical and chemical soil properties, soil moisture and temperature, ground cover, agrotechnical measures applied and the resident microbial population.

  11. Glycerine associated molecules with herbicide for controlling ...

    African Journals Online (AJOL)

    ciganinha”, belongs to the family Bignoniaceae. The only way to control this plant species in crop fields is by the application of herbicides on the stump or directly on the stem. The present study aimed to analyze the effect of glycerine in controlling A.

  12. Comparing Metabolic Functionalities, Community Structures, and Dynamics of Herbicide-Degrading Communities Cultivated with Different Substrate Concentrations

    DEFF Research Database (Denmark)

    Gözdereliler, Erkin; Boon, Nico; Aamand, Jens

    2013-01-01

    Two 4-chloro-2-methylphenoxyacetic acid (MCPA)-degrading enrichment cultures selected from an aquifer on low (0.1 mg liter−1) or high (25 mg liter−1) MCPA concentrations were compared in terms of metabolic activity, community composition, population growth, and single cell physiology. Different...... community compositions and major shifts in community structure following exposure to different MCPA concentrations were observed using both 16S rRNA gene denaturing gradient gel electrophoresis fingerprinting and pyrosequencing. The communities also differed in their MCPA-mineralizing activities...... activity in cultures selected on low herbicide concentrations. This suggests that LNA bacteria may play a role in degradation of low herbicide concentrations in aquifers impacted by agriculture. This study shows that subpopulations of herbicide-degrading bacteria that are adapted to different pesticide...

  13. [Determination of acetanilide herbicide residues in tea by gas chromatography-mass spectrometry with two different ionization techniques].

    Science.gov (United States)

    Shen, Weijian; Xu, Jinzhong; Yang, Wenquan; Shen, Chongyu; Zhao, Zengyun; Ding, Tao; Wu, Bin

    2007-09-01

    An analytical method of solid phase extraction-gas chromatography-mass spectrometry with two different ionization techniques was established for simultaneous determination of 12 acetanilide herbicide residues in tea-leaves. Herbicides were extracted from tea-leaf samples with ethyl acetate. The extract was cleaned-up on an active carbon SPE column connected to a Florisil SPE column. Analytical screening was determined by the technique of gas chromatography (GC)-mass spectrometry (MS) in the selected ion monitoring (SIM) mode with either electron impact ionization (EI) or negative chemical ionization (NCI). It is reliable and stable that the recoveries of all herbicides were in the range from 50% to 110% at three spiked levels, 10 microg/kg, 20 microg/kg and 40 microg/kg, and the relative standard deviations (RSDs) were no more than 10.9%. The two different ionization techniques are complementary as more ion fragmentation information can be obtained from the EI mode while more molecular ion information from the NCI mode. By comparison of the two techniques, the selectivity of NCI-SIM was much better than that of EI-SIM method. The sensitivities of the both techniques were high, the limit of quantitative (LOQ) for each herbicide was no more than 2.0 microg/kg, and the limit of detection (LOD) with NCI-SIM technique was much lower than that of EI-SIM when analyzing herbicides with several halogen atoms in the molecule.

  14. Maize, switchgrass, and ponderosa pine biochar added to soil increased herbicide sorption and decreased herbicide efficacy.

    Science.gov (United States)

    Clay, Sharon A; Krack, Kaitlynn K; Bruggeman, Stephanie A; Papiernik, Sharon; Schumacher, Thomas E

    2016-08-02

    Biochar, a by-product of pyrolysis made from a wide array of plant biomass when producing biofuels, is a proposed soil amendment to improve soil health. This study measured herbicide sorption and efficacy when soils were treated with low (1% w/w) or high (10% w/w) amounts of biochar manufactured from different feedstocks [maize (Zea mays) stover, switchgrass (Panicum vigatum), and ponderosa pine (Pinus ponderosa)], and treated with different post-processing techniques. Twenty-four hour batch equilibration measured sorption of (14)C-labelled atrazine or 2,4-D to two soil types with and without biochar amendments. Herbicide efficacy was measured with and without biochar using speed of seed germination tests of sensitive species. Biochar amended soils sorbed more herbicide than untreated soils, with major differences due to biochar application rate but minor differences due to biochar type or post-process handling technique. Biochar presence increased the speed of seed germination compared with herbicide alone addition. These data indicate that biochar addition to soil can increase herbicide sorption and reduce efficacy. Evaluation for site-specific biochar applications may be warranted to obtain maximal benefits without compromising other agronomic practices.

  15. Environmental determinants of the urinary concentrations of herbicides during pregnancy: the PELAGIE mother-child cohort (France).

    Science.gov (United States)

    Chevrier, Cécile; Serrano, Tania; Lecerf, Rémi; Limon, Gwendolina; Petit, Claire; Monfort, Christine; Hubert-Moy, Laurence; Durand, Gaël; Cordier, Sylvaine

    2014-02-01

    Herbicides are generally the most extensively used of the pesticides applied to agricultural crops. However, the literature contains little evidence useful in assessing the potential sources of the general population's exposure to herbicides, including by residential proximity to crops. The objective of this study was to take advantage of data from the PELAGIE mother-child cohort to identify the main determinants of the body burden of exposure to the chloroacetanilide and triazine herbicides commonly used on corn crops in Brittany, France, before 2006. Urine samples from a randomly selected subcohort of women in the first trimester of pregnancy (n=579) were assayed for herbicide metabolites. The residential exposure resulting from proximity to corn crops was assessed with satellite-image-based scores combined with meteorological data. Data on diet, drinking tap water (from the public water supply), occupations, and household herbicide use were collected by questionnaires. Herbicides were quantified in 5.3% to 39.7% of urine samples. Alachlor and acetochlor were found most frequently in the urine of women living in rural areas. The presence of dealkylated triazine metabolites in urine samples was positively associated with residential proximity to corn crops (OR=1.38, 95% CI: 1.05-1.80). Urinary metabolites of both atrazine and dealkylated triazine were correlated with tap water consumption (OR=2.94, 1.09-7.90, and OR=1.82, 1.10-3.03, respectively); hydroxylated triazine metabolites were correlated with fish intake (OR=1.48, 1.09-1.99). This study reinforces previous results that suggest that environmental contamination resulting from agricultural activities may contribute to the general population's exposure to herbicides. © 2013.

  16. Growth stage of Phalaris minor Retz. and wheat determines weed control and crop tolerance of four post-emergence herbicides

    Directory of Open Access Journals (Sweden)

    Rubia Rasool

    2017-04-01

    Full Text Available Phalaris minor Retz. has evolved multiple herbicide resistance in wheat growing areas in northwestern India. An understanding of the effect of growth stage on herbicide tolerance of wheat and control of P. minor will help in selecting the most appropriate herbicide for different situations. The weed control and crop safety of four commonly used wheat herbicides (sulfosulfuron, pinoxaden, fenoxaprop plus metribuzin and mesosulfuron plus iodosulfuron, each applied at four different wheat growth stages was investigated in field studies for two years. P. minor plants were at 1, 2-3, 3-4 and 7-8 leaf stages when the herbicides were applied at Zadok 12-Z12, Z13, Z21 and Z23 stages of wheat, respectively. Sulfosulfuron application at Z12 and Z13 wheat stages (before first irrigation, provided >80% control of P. minor and produced wheat grain yield (4.5-4.7 t/ha similar to the weed-free check (4.9 t/ha in both years. Pinoxaden, fenoxaprop plus metribuzin and mesosulfuron plus iodosulfuron application at Z12 and Z13 wheat stages recorded significantly lower wheat grain yield (3.62-3.95 t/ha due to poor weed control, crop toxicity or both. All the four herbicides were equally effective on P. minor when applied at Z21 wheat stage. At Z23 wheat stage, pinoxaden gave >90% control of P. minor and the highest wheat grain yield (4.82 t/ha. The results are expected to allow changes in the current recommendation of the timing of post-emergence herbicides for the management of P. minor in wheat.

  17. Bio stimulation for the Enhanced Degradation of Herbicides in Soil

    International Nuclear Information System (INIS)

    Kanissery, R.G; Sims, G.K

    2011-01-01

    Cleanup of herbicide-contaminated soils has been a dire environmental concern since the advent of industrial era. Although microorganisms are excellent degraders of herbicide compounds in the soil, some reparation may need to be brought about, in order to stimulate them to degrade the herbicide at a faster rate in a confined time frame. Bio stimulation through the appropriate utilization of organic amendments and nutrients can accelerate the degradation of herbicides in the soil. However, effective use of bio stimulants requires thorough comprehension of the global redox cycle during the microbial degradation of the herbicide molecules in the soil. In this paper, we present the prospects of using bio stimulation as a powerful remediation strategy for the rapid cleanup of herbicide-polluted soils.

  18. Hazard and risk of herbicides for marine microalgae.

    Science.gov (United States)

    Sjollema, Sascha B; Martínezgarcía, Gema; van der Geest, Harm G; Kraak, Michiel H S; Booij, Petra; Vethaak, A Dick; Admiraal, Wim

    2014-04-01

    Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects of four ubiquitous herbicides (atrazine, diuron, Irgarol(®)1051 and isoproturon) and herbicide mixtures on marine microalgae. Using a Pulse Amplitude Modulation (PAM) fluorometry based bioassay we demonstrated a clear species and herbicide specific toxicity and showed that the current environmental legislation does not protect algae sufficiently against diuron and isoproturon. Although a low actual risk of herbicides in the field was demonstrated, monitoring data revealed that concentrations occasionally reach potential effect levels. Hence it cannot be excluded that herbicides contribute to observed changes in phytoplankton species composition in coastal waters, but this is likely to occur only occasionally. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Herbicide tolerance and seed survival of grain amaranth (Amaranthus sp.)

    DEFF Research Database (Denmark)

    Kudsk, Per; Taberner, Andreu; de Troiani, Rosa M.

    2012-01-01

    Amaranth is receiving increasing attention as an alternative crop to small grain cereals. From a weed control point of view cultivation of amaranth poses two problems. Firstly, amaranth grows slowly after emergence and hence is very susceptible to competition by weeds and secondly, seed losses...... herbicides examined only clomazone, clopyralid, phenmedipham and triflusulfuron were tolerated by amaranth. Applying clomazone early postemergent instead of pre-emergent provided full crop tolerance even at the highest doses (Pcaused less...... crop damage applied at the 4-6 leaf stage compared to the 2-4 leaf stage while clopyralid was selective at both growth stages. The seed survival studies revealed differences between the countries with higher viability in Spain (up to 18%) than in Argentina and Denmark (up to 6%). Our results showed...

  20. Low-impact chemical weed control techniques in UNESCO World Heritage Sites of Cuba.

    Science.gov (United States)

    Hernandez-Enriquez, O; Alvarez, R; Morelli, F; Bastida, F; Camacho, D; Menendez, J

    2012-01-01

    Dichrostachys cinerea is a thorny, acacia-like, fast-growing woody bush which invades fields, wasteland, road sides and other disturbed areas. This gregarious species has become a very aggressive invasive weed in Cuba, where no native predators or pathogens are found. It often encroaches in fallows, overgrazed areas and mismanaged veld. D. cinerea is a very difficult weed to eliminate because of its active suckering, and is liable to produce dense thickets which are quite impenetrable on account of the density and abundance of its long, stiff, sharp thorns. In the Valle de los Ingenios area (Cuba Central), the tree is unchecked and forms veritable forests in areas on which cane growing has been discontinued. Physical management by cutting and burning the plants is not a very efficient control method, since the seeds survive in the soil, and they grow very fast. Therefore, chemical methods via the use of herbicides are often necessary to eradicate this weed. A preliminary study using glyphosate and auxin-like herbicides (2,4-D + picloram, MCPA, and MCPA + 2,4-D) plus adjuvants has been carried out in order to elucidate the best mixtures rendering maximum weed control with minimum herbicide rate and environmental stress. None of the herbicides used except glyphosate and 2,4-D + picloram showed acceptable mortality rates (75-80%) at the recommended doses tested. In the failed herbicide treatments, only the use of double herbicide rates succeeded in controlling marabou. The herbicide mixture of 2,4-D + picloram formulated with either a non-ionic surfactant or a mixture of fatty acid esters was the best option to control D. cinerea in terms of maximum effectiveness and minimum environmental stress, as the reduction in active ingredients applied to the environment was x3 in these two adjuvant-amended formulations compared to 2,4-D + picloram alone.

  1. Engineering Evaluation of International Low Impact Docking System Latch Hooks

    Science.gov (United States)

    Martinez, J.; Patin, R.; Figert, J.

    2013-01-01

    The international Low Impact Docking System (iLIDS) provides a structural arrangement that allows for visiting vehicles to dock with the International Space Station (ISS) (Fig 1). The iLIDS docking units are mechanically joined together by a series of active and passive latch hooks. In order to preserve docking capability at the existing Russian docking interfaces, the iLIDS latch hooks are required to conform to the existing Russian design. The latch hooks are classified as being fail-safe. Since the latch hooks are fail-safe, the hooks are not fracture critical and a fatigue based service life assessment will satisfy the structural integrity requirements. Constant amplitude fatigue testing to failure on four sets of active/passive iLIDS latch hooks was performed at load magnitudes of 10, 11, and 12 kips. Failure analysis of the hook fatigue failures identified multi-site fatigue initiation that was effectively centered about the hook mid-plane (consistent with the 3D model results). The fatigue crack initiation distribution implies that the fatigue damage accumulation effectively results in a very low aspect ratio surface crack (which can be simulated as thru-thickness crack). Fatigue damage progression resulted in numerous close proximity fatigue crack initiation sites. It was not possible to determine if fatigue crack coalescence occurs during cyclic loading or as result of the fast fracture response. The presence of multiple fatigue crack initiation sites on different planes will result in the formation of ratchet marks as the cracks coalesce. Once the stable fatigue crack becomes unstable and the fast fracture advances across the remaining ligament and the plane stress condition at a free-surface will result in failure along a 45 deg. shear plane (slant fracture) and the resulting inclined edge is called a shear lip. The hook thickness on the plane of fatigue crack initiation is 0.787". The distance between the shear lips on this plane was on the order of 0

  2. Electrochemical degradation and mineralization of glyphosate herbicide.

    Science.gov (United States)

    Tran, Nam; Drogui, Patrick; Doan, Tuan Linh; Le, Thanh Son; Nguyen, Hoai Chau

    2017-12-01

    The presence of herbicide is a concern for both human and ecological health. Glyphosate is occasionally detected as water contaminants in agriculture areas where the herbicide is used extensively. The removal of glyphosate in synthetic solution using advanced oxidation process is a possible approach for remediation of contaminated waters. The ability of electrochemical oxidation for the degradation and mineralization of glyphosate herbicide was investigated using Ti/PbO 2 anode. The current intensity, treatment time, initial concentration and pH of solution are the influent parameters on the degradation efficiency. An experimental design methodology was applied to determine the optimal condition (in terms of cost/effectiveness) based on response surface methodology. Glyphosate concentration (C 0  = 16.9 mg L -1 ) decreased up to 0.6 mg L -1 when the optimal conditions were imposed (current intensity of 4.77 A and treatment time of 173 min). The removal efficiencies of glyphosate and total organic carbon were 95 ± 16% and 90.31%, respectively. This work demonstrates that electrochemical oxidation is a promising process for degradation and mineralization of glyphosate.

  3. Raw or incubated olive-mill wastes and its biotransformed products as agricultural soil amendments-effect on sorption-desorption of triazine herbicides.

    Science.gov (United States)

    Delgado-Moreno, Laura; Almendros, Gonzalo; Peña, Aránzazu

    2007-02-07

    Raw olive-mill waste and soil amendments obtained from their traditional composting or vermicomposting were added, at rates equivalent to 200 Mg ha-1, to a calcareous silty clay loam soil in a laboratory test, in order to improve its fertility and physicochemical characteristics. In particular, the effects on the sorption-desorption processes of four triazine herbicides have been examined. We found that comparatively hydrophobic herbicides terbuthylazine and prometryn increased their retention on amended soil whereas the more polar herbicides simazine and cyanazine were less affected. Soil application of olive cake, without transformation, resulted in the highest herbicide retention. Its relatively high content in aliphatic fractions and lipids could explain the increased herbicide retention through hydrophobic bonding and herbicide diffusion favored by poorly condensed macromolecular structures. On the other hand, the condensed aromatic structure of the compost and vermicompost from olive cake could hinder diffusion processes, resulting in lower herbicide sorption. In fact, the progressive humification in soil of olive-mill solid waste led to a decrease of sorption capacity, which suggested important changes in organic matter quality and interactions during the mineralization process. When soil amended with vermicompost was incubated for different periods of time, the enhanced herbicide sorption capacity persisted for 2 months. Pesticide desorption was reduced by the addition of fresh amendments but was enhanced during the transformation process of amendments in soil. Our results indicate the potential of soil amendments based on olive-mill wastes in the controlled, selective release of triazine herbicides, which varies depending on the maturity achieved by their biological transformation.

  4. Phytotoxicity of Four Photosystem II Herbicides to Tropical Seagrasses

    Science.gov (United States)

    Flores, Florita; Collier, Catherine J.; Mercurio, Philip; Negri, Andrew P.

    2013-01-01

    Coastal waters of the Great Barrier Reef (GBR) are contaminated with agricultural pesticides, including the photosystem II (PSII) herbicides which are the most frequently detected at the highest concentrations. Designed to control weeds, these herbicides are equally potent towards non-target marine species, and the close proximity of seagrass meadows to flood plumes has raised concerns that seagrasses may be the species most threatened by herbicides from runoff. While previous work has identified effects of PSII herbicides on the photophysiology, growth and mortality in seagrass, there is little comparative quantitative toxicity data for seagrass. Here we applied standard ecotoxicology protocols to quantify the concentrations of four priority PSII herbicides that inhibit photochemistry by 10, 20 and 50% (IC10, IC20 and IC50) over 72 h in two common seagrass species from the GBR lagoon. The photosystems of seagrasses Zostera muelleri and Halodule uninervis were shown to be generally more sensitive to the PSII herbicides Diuron, Atrazine, Hexazinone and Tebuthiuron than corals and tropical microalgae. The herbicides caused rapid inhibition of effective quantum yield (∆F/F m ′), indicating reduced photosynthesis and maximum effective yields (Fv/Fm) corresponding to chronic damage to PSII. The PSII herbicide concentrations which affected photosynthesis have been exceeded in the GBR lagoon and all of the herbicides inhibited photosynthesis at concentrations lower than current marine park guidelines. There is a strong likelihood that the impacts of light limitation from flood plumes and reduced photosynthesis from PSII herbicides exported in the same waters would combine to affect seagrass productivity. Given that PSII herbicides have been demonstrated to affect seagrass at environmental concentrations, we suggest that revision of environmental guidelines and further efforts to reduce PSII herbicide concentrations in floodwaters may both help protect seagrass meadows

  5. Phytotoxicity of four photosystem II herbicides to tropical seagrasses.

    Science.gov (United States)

    Flores, Florita; Collier, Catherine J; Mercurio, Philip; Negri, Andrew P

    2013-01-01

    Coastal waters of the Great Barrier Reef (GBR) are contaminated with agricultural pesticides, including the photosystem II (PSII) herbicides which are the most frequently detected at the highest concentrations. Designed to control weeds, these herbicides are equally potent towards non-target marine species, and the close proximity of seagrass meadows to flood plumes has raised concerns that seagrasses may be the species most threatened by herbicides from runoff. While previous work has identified effects of PSII herbicides on the photophysiology, growth and mortality in seagrass, there is little comparative quantitative toxicity data for seagrass. Here we applied standard ecotoxicology protocols to quantify the concentrations of four priority PSII herbicides that inhibit photochemistry by 10, 20 and 50% (IC10, IC20 and IC50) over 72 h in two common seagrass species from the GBR lagoon. The photosystems of seagrasses Zosteramuelleri and Haloduleuninervis were shown to be generally more sensitive to the PSII herbicides Diuron, Atrazine, Hexazinone and Tebuthiuron than corals and tropical microalgae. The herbicides caused rapid inhibition of effective quantum yield (∆F/F m '), indicating reduced photosynthesis and maximum effective yields (Fv/Fm ) corresponding to chronic damage to PSII. The PSII herbicide concentrations which affected photosynthesis have been exceeded in the GBR lagoon and all of the herbicides inhibited photosynthesis at concentrations lower than current marine park guidelines. There is a strong likelihood that the impacts of light limitation from flood plumes and reduced photosynthesis from PSII herbicides exported in the same waters would combine to affect seagrass productivity. Given that PSII herbicides have been demonstrated to affect seagrass at environmental concentrations, we suggest that revision of environmental guidelines and further efforts to reduce PSII herbicide concentrations in floodwaters may both help protect seagrass meadows of

  6. Phytotoxicity of Four Photosystem II Herbicides to Tropical Seagrasses

    OpenAIRE

    Flores, Florita; Collier, Catherine J.; Mercurio, Philip; Negri, Andrew P.

    2013-01-01

    Coastal waters of the Great Barrier Reef (GBR) are contaminated with agricultural pesticides, including the photosystem II (PSII) herbicides which are the most frequently detected at the highest concentrations. Designed to control weeds, these herbicides are equally potent towards non-target marine species, and the close proximity of seagrass meadows to flood plumes has raised concerns that seagrasses may be the species most threatened by herbicides from runoff. While previous work has identi...

  7. Phytotoxicity of four photosystem II herbicides to tropical seagrasses.

    Directory of Open Access Journals (Sweden)

    Florita Flores

    Full Text Available Coastal waters of the Great Barrier Reef (GBR are contaminated with agricultural pesticides, including the photosystem II (PSII herbicides which are the most frequently detected at the highest concentrations. Designed to control weeds, these herbicides are equally potent towards non-target marine species, and the close proximity of seagrass meadows to flood plumes has raised concerns that seagrasses may be the species most threatened by herbicides from runoff. While previous work has identified effects of PSII herbicides on the photophysiology, growth and mortality in seagrass, there is little comparative quantitative toxicity data for seagrass. Here we applied standard ecotoxicology protocols to quantify the concentrations of four priority PSII herbicides that inhibit photochemistry by 10, 20 and 50% (IC10, IC20 and IC50 over 72 h in two common seagrass species from the GBR lagoon. The photosystems of seagrasses Zosteramuelleri and Haloduleuninervis were shown to be generally more sensitive to the PSII herbicides Diuron, Atrazine, Hexazinone and Tebuthiuron than corals and tropical microalgae. The herbicides caused rapid inhibition of effective quantum yield (∆F/F m ', indicating reduced photosynthesis and maximum effective yields (Fv/Fm corresponding to chronic damage to PSII. The PSII herbicide concentrations which affected photosynthesis have been exceeded in the GBR lagoon and all of the herbicides inhibited photosynthesis at concentrations lower than current marine park guidelines. There is a strong likelihood that the impacts of light limitation from flood plumes and reduced photosynthesis from PSII herbicides exported in the same waters would combine to affect seagrass productivity. Given that PSII herbicides have been demonstrated to affect seagrass at environmental concentrations, we suggest that revision of environmental guidelines and further efforts to reduce PSII herbicide concentrations in floodwaters may both help protect

  8. Seletividade e eficácia de controle de plantas daninhas pela associação entre óleo fúsel e herbicidas em cana-de-açúcar Selectivity and weed control efficacy of fusel oil and herbicide association in sugarcane

    Directory of Open Access Journals (Sweden)

    I.V. Pizzo

    2010-06-01

    . Entretanto, diuron+hexazinone e amicarbazone em dose completa associados com óleo fúsel não foram seletivos à concentração de sólidos solúveis no caldo e na produção de colmos, respectivamente.This work aimed to study the selectivity of fusel oil and herbicide association in the sugarcane cultivar IAC93-3046, and the efficacy of controlling the species Panicum maximum, Amaranthus deflexus, Ipomoea quamoclit, Brachiaria decumbens and Euphorbia heterophylla. The experiment was set up at the Instituto Agronômico/Centro de Cana in Ribeirão Preto, Brazil, in a randomized block design with 10 treatments and 4 replicates. The plots were composed of six 4 m sugarcane lines, 1.50 m (36 m² spaced, with half being sown with weeds for control evaluation, and the other half without weeds for selectivity evaluation. The treatments were diuron+hexazinone (1,170+330 g ha ¹; diuron+hexazinone (1,170+330 g ha-1 + fusel oil (25.0 L ha-1; diuron+hexazinone (819+231 g ha-1 + fusel oil (25.0 L ha-1; metribuzin (1,920 g ha-1; metribuzin (1,920 g ha-1 + fusel oil (25.0 L ha-1; metribuzin (1,344 g ha-1 + fusel oil (25.0 L ha-1; amicarbazone (1,400 g ha-1; amicarbazone (1,400 g ha-1 + fusel oil (25.0 L ha-1 and amicarbazone (980 g ha-1 + fusel oil (25.0 L ha-1 and no herbicides. The application was performed with pressurized sprayer and 250 L ha-1 volume under post-emergence of the culture (30 cm and weeds (10-2 cm. The herbicides diuron+hexazinone, metribuzin and amicarbazone were effective in controlling all the species alone, but only I. quamoclit and E. heterophylla did not present a satisfactory control at full dose and 70% of the dose combined with fusel oil. The same treatments were also selective for sugarcane cultivar IACSP 93-3046, when the variables height, stand, diameter and stalk yield, as well as the qualitative attributes were compared to the control. However, diuron + hexazinone and amicarbazone at a full dose associated with fusel oil were not selective for Brix% juice

  9. Occurrence of dichloroacetamide herbicide safeners and co-applied herbicides in midwestern U.S. streams

    Science.gov (United States)

    Woodward, Emily; Hladik, Michelle; Kolpin, Dana W.

    2018-01-01

    Dichloroacetamide safeners (e.g., AD-67, benoxacor, dichlormid, and furilazole) are co-applied with chloroacetanilide herbicides to protect crops from herbicide toxicity. While such safeners have been used since the early 1970s, there are minimal data about safener usage, occurrence in streams, or potential ecological effects. This study focused on one of these research gaps, occurrence in streams. Seven Midwestern U.S. streams (five in Iowa and two in Illinois), with extensive row-crop agriculture, were sampled at varying frequencies from spring 2016 through summer 2017. All four safeners were detected at least once; furilazole was the most frequently detected (31%), followed by benoxacor (29%), dichlormid (15%), and AD-67 (2%). The maximum concentrations ranged from 42 to 190 ng/L. Stream detections and concentrations of safeners appear to be driven by a combination of timing of application (spring following herbicide application) and precipitation events. Detected concentrations were below known toxicity levels for aquatic organisms.

  10. Effects of Low-impact Development of Infiltration and Storage Facilities on Urban Runoff Management in City of Sanandaj

    Directory of Open Access Journals (Sweden)

    Jamil Bahrami

    2017-11-01

    Full Text Available In recent years, low-impact development (LID has been well established as a method to provide the best and most affordable solutions for managing and alleviating the negative impacts of urban floods. Application of this practical method is regarded as a major step toward sustainable development as it employs eco-friendly storage instruments, reduces the effects of urbanization on impervious surfaces, and helps water infiltration to recharge groundwater resuorces. Although low-impact development tools have proved effective in the management of surface water resources and conservation of water quality, finding proper locations for the deployment of the equipment and the optimal use of each tool are still questions of much controversy and no definitive solutions are provided yet as environmental conditions keep changing. The present study exploits bio-retention cells, rain barrels, green roofs, and vegetable swales as storage instruments under different rainfall scenarios with return periods from 2 to 100 years extracted from the statistical data of Sanadaj City to determine the flood volumes and hydrographs for each sub-basin before and after the low-impact development tools are employed. Moreover, SWMM 5.1 software developed by the American Environmental Protection Agency is used to develop hydraulic and hydrologic models of the basin and the changes are monitored with each development tool selected. The most outstanding results obtained from this study include the change observed in thet form of hydrograph, a reduction of 50% in time of concentration, and reductions of 35 to 50% in peak flow in the city of Sanadaj as a result of employing the low-impact development method. Conclusion: Classification of the equipment into infiltration and storage tools used for urban runoff control allows the best runoff control model to be developed such that the grounds are prepared not only for the return to the conditions before a certain development took

  11. Characterization of cholinesterases in Chironomus riparius and the effects of three herbicides on chlorpyrifos toxicity.

    Science.gov (United States)

    Pérez, Joanne; Monteiro, Marta S; Quintaneiro, Carla; Soares, Amadeu M V M; Loureiro, Susana

    2013-11-15

    In this study, the toxicities of four pesticides (the herbicides atrazine, terbuthylazine, metolachlor and the insecticide chlorpyrifos) previously detected in the Alqueva reservoir/dam (south of Portugal) were evaluated individually and in binary combinations of the herbicides and the insecticide using fourth-instar larvae of the aquatic midge Chironomus riparius. Chlorpyrifos induced toxicity to midges in all the 48 h toxicity bioassays performed. The swimming behaviour of the larvae was impaired, with EC50 values ranging from 0.15 to 0.17 μg/L. However, neither s-triazine (atrazine and terbuthylazine) herbicides nor metolachlor alone at concentrations up to 200 μg/L caused significant toxicity to C. riparius. When combined with both s-triazine herbicides, chlorpyrifos toxicity was enhanced by approximately 2-fold when tested in a binary mixture experimental setup, at the 50% effective concentration levels. To evaluate how chlorpyrifos toxicity was being increased, the cholinesterases (ChE) were characterized biochemically using different substrates and selective inhibitors. The results obtained suggested that the main enzyme present in this species is acetylcholinesterase (AChE) and therefore it was assayed upon C. riparius exposures to all pesticides individually and as binary mixtures. Although atrazine and terbuthylazine are not effective inhibitors of AChE, the potentiation of chlorpyrifos toxicity by the two s-triazine herbicides was associated with a potentiation in the inhibition of AChE in midges; both s-triazine herbicides at 200 μg/L increased the inhibition of the AChE activity by 7 and 8-fold, respectively. A strong correlation was observed between swimming behaviour disturbances of larvae and the inhibition of the AChE activity. In contrast, metolachlor did not affect chlorpyrifos toxicity at any of the concentrations tested. Therefore, the herbicides atrazine and terbuthylazine can act as synergists in the presence of chlorpyrifos, increasing

  12. Is hormesis an underestimated factor in the development of herbicide resistance?

    Directory of Open Access Journals (Sweden)

    Belz, Regina G.

    2014-02-01

    Full Text Available The growing impact of herbicide resistant weeds increasingly affects weed management and the delay of resistance evolution has become a major task of chemical weed control. Hormesis and, thus, the phenomenon that low doses of herbicides can boost weed growth could be of importance in this regard since the recommended field rate may represent a low dose for weeds that have evolved resistance to the applied herbicide and, thus, a potential hormetic dose. Applying the field rate may thus not only directly select resistant biotypes, it may also indirectly promote the success and spread of resistant biotypes via hormesis. Nevertheless, hormetic effects in resistant weeds are hitherto merely randomly observed and, thus, a clear quantitative basis to judge the significance of hormesis for resistance evolution is lacking. Therefore, this study aimed at quantifying the degree and frequency of herbicide hormesis in sensitive and resistant weed species in order to provide a first indication of whether the phenomenon deserves consideration as a potential factor contributing to the development of herbicide resistance. In germination assays complete dose-response experiments were conducted with sensitive and resistant biotypes of Matricaria inodora (ALS-target-site resistant; treated with iodosulfuron-methyl-sodium/mesosulfuron-methyl, Eleusine indica (glyphosateresistant; treated with glyphosate, and Chenopodium album (triazine/triazinone-target-site resistant; treated with terbuthylazine. After 10 days of cultivation under controlled conditions plant growth was analyzed by measuring shoot/root length and mass. Results indicated that herbicide hormesis occurred on average with a total frequency of 29% in sensitive/resistant biotypes with an average growth increase of 53% occurring typically within a dose zone exceeding 350fold. Hormetic effects occurred, however, very variable and only for specific endpoints and not plant growth in general. If such a

  13. Herbicide injury induces DNA methylome alterations in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Gunjune Kim

    2017-07-01

    Full Text Available The emergence of herbicide-resistant weeds is a major threat facing modern agriculture. Over 470 weedy-plant populations have developed resistance to herbicides. Traditional evolutionary mechanisms are not always sufficient to explain the rapidity with which certain weed populations adapt in response to herbicide exposure. Stress-induced epigenetic changes, such as alterations in DNA methylation, are potential additional adaptive mechanisms for herbicide resistance. We performed methylC sequencing of Arabidopsis thaliana leaves that developed after either mock treatment or two different sub-lethal doses of the herbicide glyphosate, the most-used herbicide in the history of agriculture. The herbicide injury resulted in 9,205 differentially methylated regions (DMRs across the genome. In total, 5,914 of these DMRs were induced in a dose-dependent manner, wherein the methylation levels were positively correlated to the severity of the herbicide injury, suggesting that plants can modulate the magnitude of methylation changes based on the severity of the stress. Of the 3,680 genes associated with glyphosate-induced DMRs, only 7% were also implicated in methylation changes following biotic or salinity stress. These results demonstrate that plants respond to herbicide stress through changes in methylation patterns that are, in general, dose-sensitive and, at least partially, stress-specific.

  14. A membrane-based ELISA assay for the herbicide Isoproturon in soil samples

    OpenAIRE

    Baskeyfield, Damian E. H.; Davis, Frank; Magan, Naresh; Tothill, Ibtisam E.

    2012-01-01

    A membrane based enzyme linked immunosorbent assay (MELISA) for the detection of a common herbicide, isoproturon is described. A heterogeneous competitive ELISA was the format chosen for isoproturon detection. An immunoassay system with a horseradish peroxidase (HRP) labeled polyclonal antibody preparation was developed and characterized before suitable sensitivity and selectivity for isoproturon were attained. After development as a microtiter plate immunoassay, the system was transferred to...

  15. Approaches to early detection of herbicide resistance in Apera spica-venti regarding intra- and inter-field situations

    DEFF Research Database (Denmark)

    Schulz, Andrea; Mathiassen, Solvejg K; de Mol, Friederike

    2014-01-01

    at answering the questions: (1) Can the intra-field distribution of an Apera spica-venti population be used to indicate the first steps in the evolution of resistance? Is the selection of field populations based on casual observations of farmers an approach to get a reasonable overview on the resistance status...... differences in the susceptibility of samples collected within the same field. Herbicide efficacy was not plant density-dependent, but it was related to spatial plant distribution depending on the processing direction in the field. The inter-field situation survey confirmed resistance to at least one herbicide......, resistance was only confirmed in 56% of the fields in which farmers suspected resistance indicating that poor herbicide performance can be caused by other reasons as for example poor environmental conditions....

  16. Removal of glyphosate herbicide from water using biopolymer membranes.

    Science.gov (United States)

    Carneiro, Rafael T A; Taketa, Thiago B; Gomes Neto, Reginaldo J; Oliveira, Jhones L; Campos, Estefânia V R; de Moraes, Mariana A; da Silva, Camila M G; Beppu, Marisa M; Fraceto, Leonardo F

    2015-03-15

    Enormous amounts of pesticides are manufactured and used worldwide, some of which reach soils and aquatic systems. Glyphosate is a non-selective herbicide that is effective against all types of weeds and has been used for many years. It can therefore be found as a contaminant in water, and procedures are required for its removal. This work investigates the use of biopolymeric membranes prepared with chitosan (CS), alginate (AG), and a chitosan/alginate combination (CS/AG) for the adsorption of glyphosate present in water samples. The adsorption of glyphosate by the different membranes was investigated using the pseudo-first order and pseudo-second order kinetic models, as well as the Langmuir and Freundlich isotherm models. The membranes were characterized regarding membrane solubility, swelling, mechanical, chemical and morphological properties. The results of kinetics experiments showed that adsorption equilibrium was reached within 4 h and that the CS membrane presented the best adsorption (10.88 mg of glyphosate/g of membrane), followed by the CS/AG bilayer (8.70 mg of glyphosate/g of membrane). The AG membrane did not show any adsorption capacity for this herbicide. The pseudo-second order model provided good fits to the glyphosate adsorption data on CS and CS/AG membranes, with high correlation coefficient values. Glyphosate adsorption by the membranes could be fitted by the Freundlich isotherm model. There was a high affinity between glyphosate and the CS membrane and moderate affinity in the case of the CS/AG membrane. Physico-chemical characterization of the membranes showed low values of solubility in water, indicating that the membranes are stable and not soluble in water. The SEM and AFM analysis showed evidence of the presence of glyphosate on CS membranes and on chitosan face on CS/AG membranes. The results showed that the glyphosate herbicide can be adsorbed by chitosan membranes and the proposed membrane-based methodology was successfully used to

  17. Adsorption of chloroacetanilide herbicides on soil and its components. III. Influence of clay acidity, humic acid coating and herbicide structure on acetanilide herbicide adsorption on homoionic clays.

    Science.gov (United States)

    Liu, Wei-ping; Fang, Zhuo; Liu, Hui-jun; Yang, Wei-chun

    2002-04-01

    Adsorption of chloroacetanilide herbicides on homoionic montmorillonite, soil humic acid, and their mixtures was studied by coupling batch equilibration and FT-IR analysis. Adsorption isotherms of acetochlor, alachlor, metolachlor and propachlor on Ca(2+)-, Mg(2+)-, Al(3+)- and Fe(3+)-saturated clays were well described by the Freundlich equation. Regardless of the type of exchange cations, Kf decreased in the order of metolachlor > acetolachlor > alachlor > propachlor on the same clay. FT-IR spectra showed that the carbonyl group of the herbicide molecule was involved in binding, probably via H-bond with water molecules in the clay interlayer. The type and position of substitutions around the carbonyl group may have affected the electronegativity of oxygen, thus influencing the relative adsorption of these herbicides. For the same herbicide, adsorption on clay increased in the order of Mg2+ < Ca2+ < Al3+ < or = Fe3+ which coincided with the increasing acidity of homoionic clays. Acidity of cations may have affected the protonation of water, and thus the strength of H-bond between the clay water and herbicide. Complexation of clay and humic acid resulted in less adsorption than that expected from independent adsorption by the individual constituents. The effect varied with herbicides, but the greatest decrease in adsorption occurred at a 60:40 clay-to-humic acid ratio for all the herbicides. Causes for the decreased adsorption need to be characterized to better understand adsorption mechanisms and predict adsorption from soil compositions.

  18. Selection of species tolerant to the herbicide sulfentrazone with potential for phytoremediation of contaminated soilsSeleção de espécies tolerantes ao herbicida sulfentrazone com potencial para a fitorremediação de solos contaminados

    Directory of Open Access Journals (Sweden)

    João Carlos Madalão

    Full Text Available This paper aimed to select species with potential for phytoremediation of soils contaminated with the herbicide sulfentrazone. Eight species were evaluated: Arachis pintoi, Eleusine coracana, Crotalaria spectabilis, Crotalaria ochroleuca, Cajanus cajan, Leucaena leucocephala, Stizolobium cinereum, and Raphanus sativus. The experiment was set-up inside a greenhouse, using pots with a capacity of 6dm3 filled with soil samples collected at a depth of 0-20cm. The experimental design was arranged into randomised blocks in a factorial scheme (8 × 5 with four replications, which consisted of the combination between the species and five doses of sulfentrazone (0, 200, 400, 800, and 1,600g ha-1. The herbicide phytotoxicity, plant heights, and dry masses of shoots and roots were evaluated. The species Cajanus cajan and Leucaena leucocephala had a higher tolerance to sulfentrazone up to a dose of 400g ha-1, showing minor symptoms of phytotoxicity and smaller decreases in plant heights and in dry matter accumulation, both in the shoots and roots, when compared to the control treatment, indicating, thus, the potential to be used for further studies on phytoremediation of sulfentrazone in soil. Este trabalho teve como objetivo selecionar espécies com potencial para a fitorremediação de solos contaminados com o herbicida sulfentrazone. Foram avaliadas oito espécies: Arachis pintoi, Eleusine coracana, Crotalaria spectabilis, Crotalaria ochroleuca, Cajanus cajan, Leucaena leucocephala, Stizolobium cinereum e Raphanus sativus. O experimento foi instalado em casa de vegetação, com a utilização de vasos com capacidade para 6 dm3 preenchidos com porções de solo coletadas na profundidade de 0-20 cm. O delineamento experimental foi o de blocos casualizados em esquema fatorial 8 × 5, com quatro repetições, composto pela combinação entre as espécies e cinco doses do sulfentrazone (0, 200, 400, 800 e 1.600 g ha-1. Foram avaliadas a fitotoxicidade do

  19. Getting More Ecologically Relevant Information from Laboratory Tests: Recovery of Lemna minor After Exposure to Herbicides and Their Mixtures.

    Science.gov (United States)

    Knežević, Varja; Tunić, Tanja; Gajić, Pero; Marjan, Patricija; Savić, Danko; Tenji, Dina; Teodorović, Ivana

    2016-11-01

    Recovery after exposure to herbicides-atrazine, isoproturon, and trifluralin-their binary and ternary mixtures, was studied under laboratory conditions using a slightly adapted standard protocol for Lemna minor. The objectives of the present study were (1) to compare empirical to predicted toxicity of selected herbicide mixtures; (2) to assess L. minor recovery potential after exposure to selected individual herbicides and their mixtures; and (3) to suggest an appropriate recovery potential assessment approach and endpoint in a modified laboratory growth inhibition test. The deviation of empirical from predicted toxicity was highest in binary mixtures of dissimilarly acting herbicides. The concentration addition model slightly underestimated mixture effects, indicating potential synergistic interactions between photosynthetic inhibitors (atrazine and isoproturon) and a cell mitosis inhibitor (trifluralin). Recovery after exposure to the binary mixture of atrazine and isoproturon was fast and concentration-independent: no significant differences between relative growth rates (RGRs) in any of the mixtures (IC10 Mix , 25 Mix , and 50 Mix ) versus control level were recorded in the last interval of the recovery phase. The recovery of the plants exposed to binary and ternary mixtures of dissimilarly acting herbicides was strictly concentration-dependent. Only plants exposed to IC10 Mix , regardless of the herbicides, recovered RGRs close to control level in the last interval of the recovery phase. The inhibition of the RGRs in the last interval of the recovery phase compared with the control level is a proposed endpoint that could inform on reversibility of the effects and indicate possible mixture effects on plant population recovery potential.

  20. Evaluation of three herbicide resistance genes for use in genetic transformations and for potential crop protection in algae production.

    Science.gov (United States)

    Brueggeman, Andrew J; Kuehler, Daniel; Weeks, Donald P

    2014-09-01

    Genes conferring resistance to the herbicides glyphosate, oxyfluorfen and norflurazon were developed and tested for use as dominant selectable markers in genetic transformation of Chlamydomonas reinhardtii and as potential tools for the protection of commercial-scale algal production facilities against contamination by organisms sensitive to these broad-spectrum herbicides. A synthetic glyphosate acetyltransferase (GAT) gene, when fitted with a strong Chlamydomonas promoter, conferred a 2.7×-fold increase in tolerance to the EPSPS inhibitor, glyphosate, in transgenic cells compared with progenitor WT cells. A mutant Chlamydomonas protoporphyrinogen oxidase (protox, PPO) gene previously shown to produce an enzyme insensitive to PPO-inhibiting herbicides, when genetically engineered, generated transgenic cells able to tolerate up to 136× higher levels of the PPO inhibitor, oxyfluorfen, than nontransformed cells. Genetic modification of the Chlamydomonas phytoene desaturase (PDS) gene-based gene sequences found in various norflurazon-resistant organisms allowed production of transgenic cells tolerant to 40× higher levels of norflurazon than nontransgenic cells. The high efficiency of all three herbicide resistance genes in producing transgenic cells demonstrated their suitability as dominant selectable markers for genetic transformation of Chlamydomonas and, potentially, other eukaryotic algae. However, the requirement for high concentrations of glyphosate and its associated negative effects on cell growth rates preclude its consideration for use in large-scale production facilities. In contrast, only low doses of norflurazon and oxyfluorfen (~1.5 μm and ~0.1 μm, respectively) are required for inhibition of cell growth, suggesting that these two herbicides may prove effective in large-scale algal production facilities in suppressing growth of organisms sensitive to these herbicides. © 2014 Society for Experimental Biology, Association of Applied Biologists and

  1. Sarmentine, a natural herbicide from Piper species with multiple herbicide mechanisms of action

    Science.gov (United States)

    Sarmentine, 1-(1-pyrrolidinyl)-(2E,4E)-2,4-decadien-1-one, is a natural amide isolated from the fruits of Piper species. The compound has a number of interesting biological properties, including its broad-spectrum activity on weeds as a contact herbicide. Initial studies highlighted a similarity in ...

  2. Predicting herbicidal plant mortality with mobile photosynthesis meters

    NARCIS (Netherlands)

    Kempenaar, C.; Lotz, L.A.P.; Snel, J.F.H.; Smutny, V.; Zhang, H.J.

    2011-01-01

    Herbicide dose optimisation, i.e. maximising weed control and crop yield with herbicide dose, is an important part of integrated weed management strategies. However, the adoption of optimised dose technology and variable rate application has been limited because of the relatively long period between

  3. Herbicide volatilization trumps runoff losses, a multi-year investigation

    Science.gov (United States)

    Surface runoff and volatilization are two processes critical to herbicide off-site transport. To determine the relevance of these off-site transport mechanisms, runoff and turbulent vapor fluxes were simultaneously monitored on the same site for eight years. Site location, herbicide formulations, ...

  4. Effects of acetochlor (herbicide) on the survival and avoidance ...

    African Journals Online (AJOL)

    Jane

    2011-07-06

    Jul 6, 2011 ... These results suggested that acetochlor residues had negligible effects on P. birmanica and L. terrestris. Michalkova and Pekar (2009) and Yardim and Edwards (1998) also reported negligible effects of herbicide (glyphosate) on Pardosa agrestis. Although, we also observed negligible effects of herbicide.

  5. Estimation of herbicide bioconcentration in sugarcane (Saccharum officinarum L.

    Directory of Open Access Journals (Sweden)

    Antonio Luiz Cerdeira

    2015-04-01

    Full Text Available Sugarcane is an important crop for sugar and biofuel production in Brazil. Growers depend greatly on herbicides to produce it. This experiment used herbicide physical-chemical and sugarcane plant physiological properties to simulate herbicide uptake and estimate the bioconcentration factor (BCF. The (BCF was calculated for the steady state chemical equilibrium between the plant herbicide concentration and soil solution. Plant-water partition coefficient (sugarcane bagasse-water partition coefficient, herbicide dilution rate, metabolism and dissipation in the soil-plant system, as well as total plant biomass factors were used. In addition, we added Tebuthiuron at rate of 5.0kg a.i. ha-1 to physically test the model. In conclusion, the model showed the following ranking of herbicide uptake: sulfentrazone > picloram >tebuthiuron > hexazinone > metribuzin > simazine > ametryn > diuron > clomazone > acetochlor. Furthermore, the highest BCF herbicides showed higher Groundwater Ubiquity Score (GUS index indicating high leaching potential. We did not find tebuthiuron in plants after three months of herbicide application

  6. Plant Community Diversity After Herbicide Control of Spotted Knapweed

    OpenAIRE

    United States Department of Agriculture, Forest Service

    1992-01-01

    Herbicides were applied to four west-central Montana sites with light to moderate spotted knapweed (Centaurea maculosa Lam.) infestations. Althought knapweed suppression was high, 2 years after the spraying the communities were not converted to grass monocultures. No large declines in plant diversity were caused by the herbicides, and small depressions were probably transitory. By the third year, diversity had increased.

  7. Efficacy and economics of different herbicides in aerobic rice system ...

    African Journals Online (AJOL)

    Aerobic rice system, the most promising irrigation water saving rice production technology, is highly impeded by severe weed pressure. Weed control through the use of same herbicide causes development of herbicide resistant weed biotypes and serious problem in weed management. This study was aimed at finding out ...

  8. Herbicide-resistant crop biotechnology: potential and pitfalls

    Science.gov (United States)

    Herbicide-resistant crops are an important agricultural biotechnology that can enable farmers to effectively control weeds without harming their crops. Glyphosate-resistant (i.e. Roundup Ready) crops have been the most commercially successful varieties of herbicide-resistant crops and have been plan...

  9. Effect of four herbicides on microbial population, soil organic matter ...

    African Journals Online (AJOL)

    The effect of four herbicides (atrazine, primeextra, paraquat and glyphosate) on soil microbial population, soil organic matter and dehydrogenase activity was assessed over a period of six weeks. Soil samples from cassava farms were treated with herbicides at company recommended rates. Soil dehydrogenase activity was ...

  10. Integrated Effect of Seeding Rate, Herbicide Dosage and ...

    African Journals Online (AJOL)

    yield reductions of 26 to 63% across four bread wheat cultivars at 90 weed seedlings m-2 in. Ethiopia. Before herbicides were widely available, farmers employed cultural measures to manage weed population. Wild oat management systems have evolved to the point that producers rely on herbicides to the virtual exclusion ...

  11. ACETANILIDE HERBICIDE DEGRADATION PRODUCTS BY LC/MS

    Science.gov (United States)

    Acetanilide herbicides are frequently applied in the U.S. on crops (corn, soybeans, popcorn, etc.) to control broadleaf and annual weeds. The acetanilide and acetamide herbicides currently registered for use in the U.S. are alachlor, acetochlor, metolachlor, propachlor, flufen...

  12. Evaluation of generic and branded herbicides : technical report.

    Science.gov (United States)

    2015-03-01

    As with other generic brand products in the marketplace, generic herbicides often have a lower initial product cost than : their brand-name counterparts. While the purchase price of herbicides is important to TxDOT, it is essential to look at : more ...

  13. Hazard and risk of herbicides for marine microalgae

    International Nuclear Information System (INIS)

    Sjollema, Sascha B.; MartínezGarcía, Gema; Geest, Harm G. van der; Kraak, Michiel H.S.; Booij, Petra; Vethaak, A. Dick; Admiraal, Wim

    2014-01-01

    Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects of four ubiquitous herbicides (atrazine, diuron, Irgarol ® 1051 and isoproturon) and herbicide mixtures on marine microalgae. Using a Pulse Amplitude Modulation (PAM) fluorometry based bioassay we demonstrated a clear species and herbicide specific toxicity and showed that the current environmental legislation does not protect algae sufficiently against diuron and isoproturon. Although a low actual risk of herbicides in the field was demonstrated, monitoring data revealed that concentrations occasionally reach potential effect levels. Hence it cannot be excluded that herbicides contribute to observed changes in phytoplankton species composition in coastal waters, but this is likely to occur only occasionally. - Highlights: • The hazard of herbicides for microalgae is compound and species specific. • In general a low risk although occasional potential effect levels are reached. • Current legislation does not protect marine microalgae sufficiently. - The hazard of herbicides in the coastal waters is compound and species specific and although the general risk in the field is low, occasionally potential effect levels are reached

  14. Herbicidal cyanoacrylates with antimicrotubule mechanism of action.

    Science.gov (United States)

    Tresch, Stefan; Plath, Peter; Grossmann, Klaus

    2005-11-01

    The herbicidal mode of action of the new synthetic cyanoacrylates ethyl (2Z)-3-amino-2-cyano-4-ethylhex-2-enoate (CA1) and its isopropyl ester derivative CA2 was investigated. For initial characterization, a series of bioassays was used indicating a mode of action similar to that of mitotic disrupter herbicides such as the dinitroaniline pendimethalin. Cytochemical fluorescence studies including monoclonal antibodies against polymerized and depolymerized tubulin and a cellulose-binding domain of a bacterial cellulase conjugated to a fluorescent dye were applied to elucidate effects on cell division processes including mitosis and microtubule and cell wall formation in maize roots. When seedlings were root treated with 10 microM of CA1 or CA2, cell division activity in meristematic root tip cells decreased within 4 h. The chromosomes proceeded to a condensed state of prometaphase, but were unable to progress further in the mitotic cycle. The compounds caused a complete loss of microtubular structures, including preprophase, spindle, phragmoplast and cortical microtubules. Concomitantly, in the cytoplasm, an increase in labelling of free tubulin was observed. This suggests that the herbicides disrupt polymerization and microtubule stability, whereas tubulin synthesis or degradation appeared not to be affected. In addition, cellulose labelling in cell walls of root tip cells was not influenced. The effects of CA1 and CA2 were comparable with those caused by pendimethalin. In transgenic Arabidopsis plants expressing a green fluorescent protein-microtubule-associated protein4 fusion protein, labelled arrays of cortical microtubules in living epidermal cells of hypocotyls collapsed within 160 min after exposure to 10 microM CA1 or pendimethalin. Moreover, a dinitroaniline-resistant biotype of goosegrass (Eleusine indica (L) Gaertn) with a point mutation in alpha-tubulin showed cross-resistance against CA1 and CA2. The results strongly indicate that the cyanoacrylates are

  15. Virtual imprinting as a tool to design efficient MIPs for photosynthesis-inhibiting herbicides.

    Science.gov (United States)

    Breton, Florent; Rouillon, Regis; Piletska, Elena V; Karim, Kal; Guerreiro, Antonio; Chianella, Iva; Piletsky, Sergey A

    2007-04-15

    Molecular modelling and computational screening were used to identify functional monomers capable of interacting with several different photosynthesis-inhibiting herbicides. The process involved the design of a virtual library of molecular models of functional monomers containing polymerizable residues and residues able to interact with the template through electrostatic, hydrophobic, Van der Waals forces and dipole-dipole interactions. Each of the entries in the virtual library was probed for its possible interactions with molecular models of the template molecules. It was anticipated that the monomers giving the highest binding score would represent good candidates for the preparation of affinity polymers. Strong interactions were computationally determined between acidic functional monomers like methacrylic acid (MAA) or itaconic acid (IA) with triazines, and between vinylimidazole with bentazone and bromoxynil. Nevertheless, weaker interactions were seen with phenylureas. The corresponding blank polymers were prepared using the selected monomers and tested in the solid phase extraction (SPE) of herbicides from chloroform solutions. A good correlation was found between the binding score of the monomers and the affinities of the corresponding polymers. The use of computationally designed blanks can potentially eliminate the need for molecular imprinting, (adding a template to the monomer mixture to create specific binding sites). Data also showed that some monomers have a natural selectivity for some herbicides, which can be further enhanced by imprinting. Thus, in regard to retention on the blank polymer, we can estimate if the resulting imprinted polymer will be effective or not.

  16. Testing Transgenic Aspen Plants with bar Gene for Herbicide Resistance under Semi-natural Conditions.

    Science.gov (United States)

    Lebedev, V G; Faskhiev, V N; Kovalenko, N P; Shestibratov, K A; Miroshnikov, A I

    2016-01-01

    Obtaining herbicide resistant plants is an important task in the genetic engineering of forest trees. Transgenic European aspen plants (Populus tremula L.) expressing the bar gene for phosphinothricin resistance have been produced using Agrobacterium tumefaciens-mediated transformation. Successful genetic transformation was confirmed by PCR analysis for thirteen lines derived from two elite genotypes. In 2014-2015, six lines were evaluated for resistance to herbicide treatment under semi-natural conditions. All selected transgenic lines were resistant to the herbicide Basta at doses equivalent to 10 l/ha (twofold normal field dosage) whereas the control plants died at 2.5 l/ha. Foliar NH4-N concentrations in transgenic plants did not change after treatment. Extremely low temperatures in the third ten-day period of October 2014 revealed differences in freeze tolerance between the lines obtained from Pt of f2 aspen genotypes. Stable expression of the bar gene after overwintering outdoors was confirmed by RT-PCR. On the basis of the tests, four transgenic aspen lines were selected. The bar gene could be used for retransformation of transgenic forest trees expressing valuable traits, such as increased productivity.

  17. New Technologies for Insect-Resistant and Herbicide-Tolerant Plants.

    Science.gov (United States)

    Lombardo, Luca; Coppola, Gerardo; Zelasco, Samanta

    2016-01-01

    The advent of modern molecular biology and recombinant DNA technology has resulted in a dramatic increase in the number of insect-resistant (IR) and herbicide-tolerant (HT) plant varieties, with great economic benefits for farmers. Nevertheless, the high selection pressure generated by control strategies for weed and insect populations has led to the evolution of herbicide and pesticide resistance. In the short term, the development of new techniques or the improvement of existing ones will provide further instruments to counter the appearance of resistant weeds and insects and to reduce the use of agrochemicals. In this review, we examine some of the most promising new technologies for developing IR and HT plants, such as genome editing and antisense technologies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Determination of phenmedipham and desmedipham in a commercial herbicide by high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Lončar Eva S.

    2004-01-01

    Full Text Available Betanal AM-11 is the herbicide that is using to control one-year old weeds with wide leafs in sugar beet fields. Active ingredients of the herbicide are phenmedipham and desmedipham. Commercial emulsifiable concentrate (EC contains 80 g/L ( 10% of each active compound. We applied high performance liquid chromatography (HPLC with diode array detector (DAD at 254 nm for the determination of phenmedipham and desmedipham in commercial samples of Betanal AM-11. This method involves reversed-phase separation of the components on C-18 bonded silica with methanol-water (51+49, v/v as the eluent. The procedure was highly selective and reproducible and can be successfully used in determining contents of phenmedipham and desmedipham on micro and macro levels.

  19. Use of image analysis to assess color response on plants caused by herbicide application

    DEFF Research Database (Denmark)

    Asif, Ali; Streibig, Jens Carl; Duus, Joachim

    2013-01-01

    by herbicides. The range of color components of green and nongreen parts of the plants and soil in Hue, Saturation, and Brightness (HSB) color space were used for segmentation. The canopy color changes of barley, winter wheat, red fescue, and brome fescue caused by doses of a glyphosate and diflufenican mixture...... for the green and nongreen parts of the plants and soil were different. The relative potencies were not significantly different from one, indicating that visual and image analysis estimations were about the same. The comparison results suggest that image analysis can be used to assess color changes of plants......In herbicide-selectivity experiments, response can be measured by visual inspection, stand counts, plant mortality, and biomass. Some response types are relative to nontreated control. We developed a nondestructive method by analyzing digital color images to quantify color changes in leaves caused...

  20. Bacillus megaterium strains derived from water and soil exhibit differential responses to the herbicide mesotrione.

    Science.gov (United States)

    Dobrzanski, Tatiane; Gravina, Fernanda; Steckling, Bruna; Olchanheski, Luiz R; Sprenger, Ricardo F; Espírito Santo, Bruno C; Galvão, Carolina W; Reche, Péricles M; Prestes, Rosilene A; Pileggi, Sônia A V; Campos, Francinete R; Azevedo, Ricardo A; Sadowsky, Michael J; Beltrame, Flávio L; Pileggi, Marcos

    2018-01-01

    The intense use of herbicides for weed control in agriculture causes selection pressure on soil microbiota and water ecosystems, possibly resulting in changes to microbial processes, such as biogeochemical cycles. These xenobiotics may increase the production of reactive oxygen species and consequently affect the survival of microorganisms, which need to develop strategies to adapt to these conditions and maintain their ecological functionality. This study analyzed the adaptive responses of bacterial isolates belonging to the same species, originating from two different environments (water and soil), and subjected to selection pressure by herbicides. The effects of herbicide Callisto and its active ingredient, mesotrione, induced different adaptation strategies on the cellular, enzymatic, and structural systems of two Bacillus megaterium isolates obtained from these environments. The lipid saturation patterns observed may have affected membrane permeability in response to this herbicide. Moreover, this may have led to different levels of responses involving superoxide dismutase and catalase activities, and enzyme polymorphisms. Due to these response systems, the strain isolated from water exhibited higher growth rates than did the soil strain, in evaluations made in oligotrophic culture media, which would be more like that found in semi-pristine aquatic environments. The influence of the intracellular oxidizing environments, which changed the mode of degradation of mesotrione in our experimental model and produced different metabolites, can also be observed in soil and water at sites related to agriculture. Since the different metabolites may present different levels of toxicity, we suggest that this fact should be considered in studies on the fate of agrochemicals in different environments.

  1. Barriers to implementing low impact development approaches in Washington State roadways and highways.

    Science.gov (United States)

    2010-06-04

    Low impact development (LID) is an approach to stormwater management that seeks to mimic the natural hydrologic functions of stormwater runoff prior to development. In general, LID techniques emphasize infiltration and evapotranspiration to remove po...

  2. Novel Use of Time Domain Reflectometry in Infiltration-based Low Impact Development Practices

    Science.gov (United States)

    Low impact development (LID) practices are structures that intercept stormwater runoff and infiltrate it through a range of media types, including aggregate, rain garden media, and underlying soils. Hydrologic performance is typically evaluated by comparing inlet and underdrain o...

  3. Influence of oligomeric herbicidal ionic liquids with MCPA and Dicamba anions on the community structure of autochthonic bacteria present in agricultural soil

    Energy Technology Data Exchange (ETDEWEB)

    Ławniczak, Ł., E-mail: lukasz.k.lawniczak@wp.pl [Department of Chemical Technology, Poznan University of Technology, 60-965 Poznan (Poland); Syguda, A., E-mail: Anna.Syguda@put.poznan.pl [Department of Chemical Technology, Poznan University of Technology, 60-965 Poznan (Poland); Borkowski, A., E-mail: a.borkowski@uw.edu.pl [Faculty of Geology, University of Warsaw, 02-089 Warsaw (Poland); Cyplik, P., E-mail: pcyplik@wp.pl [Department of Biotechnology and Food Microbiology, University of Life Sciences in Poznan, 60-627 Poznan (Poland); Marcinkowska, K., E-mail: k.marcinkowska@iorpib.poznan.pl [Institute of Plant Protection - National Research Institute, Poznan 60-318 (Poland); Wolko, Ł., E-mail: wolko@o2.pl [Department of Biochemistry and Biotechnology, Poznań University of Life Sciences in Poznan, 60-632 Poznan (Poland); Praczyk, T., E-mail: t.praczyk@iorpib.poznan.pl [Institute of Plant Protection - National Research Institute, Poznan 60-318 (Poland); Chrzanowski, Ł., E-mail: Lukasz.Chrzanowski@put.poznan.pl [Department of Chemical Technology, Poznan University of Technology, 60-965 Poznan (Poland); Pernak, J., E-mail: Juliusz.Pernak@put.poznan.pl [Department of Chemical Technology, Poznan University of Technology, 60-965 Poznan (Poland)

    2016-09-01

    The aim of this study was to evaluate the impact of selected herbicidal ionic liquids (HILs), which exhibit high efficacy in terms of weed control and low toxicity, but may be persistent due to limited biodegradability, on the community structure of autochthonic bacteria present in agricultural soil. Four different oligomeric HILs (with two types of cations and different ratio of herbicidal anions) were synthesized and characterized by employing {sup 1}H and {sup 13}C NMR. The results of biodegradation assay indicated that none of the tested HILs could be classified as readily biodegradable (biodegradation rate ranged from 0 to 7%). The conducted field studies confirmed that the herbicidal efficacy of the HILs was higher compared to the reference herbicide mixture by 10 to 30%, depending on the dose and weed species. After termination of field studies, the soil treated with the tested HILs was subjected to next generation sequencing in order to investigate the potential changes in the bacterial community structure. Proteobacteria was the dominant phylum in all studied samples. Treatment with the studied HILs resulted in an increase of Actinobacteria compared to the reference herbicidal mixture. Differenced among the studied HILs were generally associated with a significantly higher abundance of Bacteroidetes in case of 1-HIL-Dicamba 1/3 and Firmicutes in case of 2-HIL-Dicamba 1/3. - Highlights: • Impact of herbicidal ionic liquids on bacterial community structure was studied. • Oligomeric herbicidal ionic liquids were effective but not readily biodegradable. • Next generation sequencing was used to evaluate shifts in bacterial abundance. • Treatment during field trials resulted in changes at class and species level. • Use of herbicidal ionic liquids affects the structure of autochthonic soil bacteria.

  4. Influence of oligomeric herbicidal ionic liquids with MCPA and Dicamba anions on the community structure of autochthonic bacteria present in agricultural soil

    International Nuclear Information System (INIS)

    Ławniczak, Ł.; Syguda, A.; Borkowski, A.; Cyplik, P.; Marcinkowska, K.; Wolko, Ł.; Praczyk, T.; Chrzanowski, Ł.; Pernak, J.

    2016-01-01

    The aim of this study was to evaluate the impact of selected herbicidal ionic liquids (HILs), which exhibit high efficacy in terms of weed control and low toxicity, but may be persistent due to limited biodegradability, on the community structure of autochthonic bacteria present in agricultural soil. Four different oligomeric HILs (with two types of cations and different ratio of herbicidal anions) were synthesized and characterized by employing "1H and "1"3C NMR. The results of biodegradation assay indicated that none of the tested HILs could be classified as readily biodegradable (biodegradation rate ranged from 0 to 7%). The conducted field studies confirmed that the herbicidal efficacy of the HILs was higher compared to the reference herbicide mixture by 10 to 30%, depending on the dose and weed species. After termination of field studies, the soil treated with the tested HILs was subjected to next generation sequencing in order to investigate the potential changes in the bacterial community structure. Proteobacteria was the dominant phylum in all studied samples. Treatment with the studied HILs resulted in an increase of Actinobacteria compared to the reference herbicidal mixture. Differenced among the studied HILs were generally associated with a significantly higher abundance of Bacteroidetes in case of 1-HIL-Dicamba 1/3 and Firmicutes in case of 2-HIL-Dicamba 1/3. - Highlights: • Impact of herbicidal ionic liquids on bacterial community structure was studied. • Oligomeric herbicidal ionic liquids were effective but not readily biodegradable. • Next generation sequencing was used to evaluate shifts in bacterial abundance. • Treatment during field trials resulted in changes at class and species level. • Use of herbicidal ionic liquids affects the structure of autochthonic soil bacteria.

  5. The effects of s-triazines on selected marine macroalgae

    International Nuclear Information System (INIS)

    Lewey, S.A.; Nummela, E.C.

    1999-01-01

    Although s-triazines have been used as herbicides for many years, their use and that of other herbicides and fungicides, in antifouling compounds is only fairly recent. The Hamble estuary, Hampshire UK has been identified as one such site. Investigations were conducted into the effects of s-triazines on selected marine macroalgae, local to that area

  6. Biotransformation and biomonitoring of phenylurea herbicide diuron.

    Science.gov (United States)

    Sharma, Priyanka; Suri, C Raman

    2011-02-01

    A Gram-positive, Micrococcus sp. strain PS-1 isolated from diuron storage site was studied for its capability of biotransformation of phenylurea herbicide diuron to a secondary metabolite, 1-(3,4-dichlorophenyl)urea (DCPU) for bioconjugation and antibody development applications. The metabolite formed associated with profound changes in bacterial cell morphology demonstrated increase in the degradation kinetics of diuron in presence of small quantity of a surfactant. The synthesized metabolite identified by chromatographic and mass spectrometry techniques was conjugated with carrier protein, and used as an immunogen for antibodies production. The generated antibody was highly specific, demonstrating excellent sensitivity against diuron. The antibody was used as receptor molecules in standard fluorescence immunoassay (FIA) format showing detection limit of 0.01 ng/mL in the optimum working concentration range of diuron with good signal precision (∼2%). The study presented first time the degradation pathway of herbicide by specific microorganism to synthesize hapten for bioconjugation and immunoassay development. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Valerian (Valeriana officinalis L. tolerance to some post-emergence herbicides

    Directory of Open Access Journals (Sweden)

    Monjezi Nadia

    2015-12-01

    Full Text Available Valerian (Valeriana officinalis L. is a medicinal plant, but its cultivation is restricted by weed competition. Therefore, three rates (0.75X, 1X, and 1.25X, where X is equal to the recommended dose of haloxyfop-R (methyl ester, sethoxydim, oxadiargyl, bentazon, oxadiazon, and oxyfluorfen were applied at the 3-4 leaf stages to valerian plants. This application was done to select the herbicide type and rate for post-controlling broadleaf and grasses weeds in this species. Herbicide injury, Soil-Plant Analyses Development (SPAD reading, number of leaves per plant, stem diameter, and fresh and dry weights were determined 10, 20, and 30 days after herbicide application. Oxyfluorfen application caused the most herbicide injury followed by bentazon. Injury increased as the rate and the days after application increased. Oxadiazon only caused significant damage 30 days after application under all three rates. Other treatments showed no marked injuries under any rate or date after application, as compared with the control. Effects on other measured traits depended on the trait, herbicide, and herbicide rate. The highest SPAD, leaf number, shoot diameter, fresh weight and dry weight, was recorded under application of 30 mg a.i. ∙ kg-1 soil oxadiargyl and 90 mg a.i. ∙ kg-1 soil oxadiazon, 81 mg a.i. ∙ kg-1 soil haloxyfop-R, 37.5 mg a.i. ∙ kg-1 soil oxadiargyl, 22.5 mg a.i. ∙ kg-1 soil oxadiargyl, 81 mg a.i. ∙ kg-1 soil haloxyfop-R, and 81 mg a.i. ∙ kg-1 soil haloxyfop-R, respectively. To sum up, the results showed that sethoxydim, oxadiargyl, and haloxyfop-R produced no significant symptoms of phytotoxicity or reduction of measured traits. This means that oxadiargyl, haloxyfop-R, and sethoxydim may be used safely for weed control of valerian at the rates used in this experiment under similar conditions.

  8. Simulation and Evaluation of Low Impact Development of Urban Residential District Based on SWMM and GIS

    Science.gov (United States)

    Huang, Tielan; Wang, Yunpeng; Zhang, Jinlan

    2017-07-01

    In this study, simulation and evaluation of low impact development in resident district was carried out based on Storm Water Management Model (SWMM) and GIS method. In the evaluation model, we added 3 kinds of low impact development facilities, namely permeable pavement, rainwater garden, and green roof. These facilities are used alone or in combination. The model was run under five different rainfall reappearing periods. The simulation results using low impact development facilities were compared with simulation results under the current situation and undeveloped state. The results show that the total amount of runoff was greatly reduced by using various types of low impact development facilities in the urban residential district. The maximum reduction rate was using permeable pavement, reached 29.9%, followed was using rainwater garden, and the worst was using green roof. The lowest cost of reduction of the total amount of runoff was using permeable pavement, the followed was using rainwater garden, and the highest was using green roof. The combination scheme of various low impact development facilities has the highest efficiency of reducing total amount of runoff, and the lowest cost, which considering of the actual situation of the study area. The study indicated that application of low impact development facilities can reduce surface runoff effectively, which should be a useful way for prevention of urban waterlogging.

  9. Evaluation of Selected Pre-Emergence Herbicides for Weed Control ...

    African Journals Online (AJOL)

    Pendimentalin had no significant effect on the plantlets across the rates tested. The best weed control was achieved with diuron applied at 25% and above, while the least weed control occurred on the control plot and these treated with 10% of atrazine and primextra Gold. However, there were no significant variations in the ...

  10. in vitro screening of selected herbicides on rhizosphere mycoflora

    African Journals Online (AJOL)

    PROF. BARTH EKWEME

    inhibited the mycelial growth of the isolated rhizosphere fungi. Growth inhibition of the ... quality of crops but also utilize essential nutrients meant for the crop. ..... Effect of seed-applied pesticide on growth ... soil fungi from oil palm plantation.

  11. Adsorption of sugar beet herbicides to Finnish soils.

    Science.gov (United States)

    Autio, Sari; Siimes, Katri; Laitinen, Pirkko; Rämö, Sari; Oinonen, Seija; Eronen, Liisa

    2004-04-01

    Three sugar beet herbicides, ethofumesate, phenmedipham and metamitron, are currently used on conventional sugar beet cultivation, while new varieties of herbicide resistant (HR) sugar beet, tolerant of glyphosate or glufosinate-ammonium, are under field testing in Finland. Little knowledge has so far been available on the adsorption of these herbicides to Finnish soils. The adsorption of these five herbicides was studied using the batch equilibrium method in 21 soil samples collected from different depths. Soil properties like organic carbon content, texture, pH and partly the phosphorus and oxide content of the soils were tested against the adsorption coefficients of the herbicides. In general, the herbicides studied could be arranged according to their adsorption coefficients as follows: glyphosate>phenmedipham>ethofumesate approximately glufosinate-ammonium>metamitron, metamitron meaning the highest risk of leaching. None of the measured soil parameters could alone explain the adsorption mechanism of these five herbicides. The results can be used in model assessments of risk for leaching to ground water resulting from weed control of sugar beet in Finland.

  12. Studies on maize inbred lines susceptibility to herbicides

    Directory of Open Access Journals (Sweden)

    Stefanović Lidija

    2010-01-01

    Full Text Available This paper presents the analysis of results obtained during long- term studies on the response of maize inbred lines to herbicides. Under the agroecological conditions of Zemun Polje the response (reaction of maize inbred lines to herbicides of different classes was investigated. Biological tests were performed and some agronomic, morphological, physiological and biochemical parameters were determined when the response of maize inbred lines to herbicides was estimated. The use of active ingredients of herbicides from triazine, acetanilide, thiocarbamate to new chemical groups (sulfonylurea etc., have been resulted in changes in weed suppression and susceptibility of inbred lines. Obtained results show that effects of herbicides on susceptible maize genotypes can be different: they can slowdown the growth and development and affect the plant height; they can also affect the stages of the tassel and ear development and at the end they can reduced grain yield of the tested inbreds. Numerous studies confirmed the existence of differences in susceptibility level of maize genotypes in relation to herbicides. According to gained results the recommendations for growers are made on the possibility of the application of new herbicides in the hybrid seed production.

  13. Rationale for a natural products approach to herbicide discovery.

    Science.gov (United States)

    Dayan, Franck E; Owens, Daniel K; Duke, Stephen O

    2012-04-01

    Weeds continue to evolve resistance to all the known modes of herbicidal action, but no herbicide with a new target site has been commercialized in nearly 20 years. The so-called 'new chemistries' are simply molecules belonging to new chemical classes that have the same mechanisms of action as older herbicides (e.g. the protoporphyrinogen-oxidase-inhibiting pyrimidinedione saflufenacil or the very-long-chain fatty acid elongase targeting sulfonylisoxazoline herbicide pyroxasulfone). Therefore, the number of tools to manage weeds, and in particular those that can control herbicide-resistant weeds, is diminishing rapidly. There is an imminent need for truly innovative classes of herbicides that explore chemical spaces and interact with target sites not previously exploited by older active ingredients. This review proposes a rationale for a natural-products-centered approach to herbicide discovery that capitalizes on the structural diversity and ingenuity afforded by these biologically active compounds. The natural process of extended-throughput screening (high number of compounds tested on many potential target sites over long periods of times) that has shaped the evolution of natural products tends to generate molecules tailored to interact with specific target sites. As this review shows, there is generally little overlap between the mode of action of natural and synthetic phytotoxins, and more emphasis should be placed on applying methods that have proved beneficial to the pharmaceutical industry to solve problems in the agrochemical industry. Published 2012 by John Wiley & Sons, Ltd.

  14. Acute and additive toxicity of ten photosystem-II herbicides to seagrass

    OpenAIRE

    Adam D. Wilkinson; Catherine J. Collier; Florita Flores; Andrew P. Negri

    2015-01-01

    Photosystem II herbicides are transported to inshore marine waters, including those of the Great Barrier Reef, and are usually detected in complex mixtures. These herbicides inhibit photosynthesis, which can deplete energy reserves and reduce growth in seagrass, but the toxicity of some of these herbicides to seagrass is unknown and combined effects of multiple herbicides on seagrass has not been tested. Here we assessed the acute phytotoxicity of 10 PSII herbicides to the seagrass Halophila ...

  15. GROWTH AND NUTRITIONAL ANALYSIS OF TREE SPECIES IN CONTAMINATED SUBSTRATE BY LEACHABLE HERBICIDES

    Directory of Open Access Journals (Sweden)

    Rebecca de Araújo Fiore

    Full Text Available ABSTRACT Ecosystems contamination by residues of pesticides requires special attention to the herbicides subject to leaching. The objective was to select tree species to rhizodegradation contaminated by residues of 2,4-D and atrazine and to recompose riparian areas to agricultural fields, then reducing the risk of contamination of water courses. A total of 36 treatments consisted of the combinations of forest species were evaluated [Inga marginata (Inga, Schizolobium parahyba (guapuruvu, Handroanthus serratifolius (ipê amarelo, Jacaranda puberula (carobinha, Cedrela fissilis (cedro, Calophyllum brasiliensis (landin, Psidium mirsinoides (goiabinha, Tibouchina glandulosa (quaresmeira, Caesalpinia férrea (pau-ferro, Caesalpinia pluviosa (sibipiruna, Terminalia argêntea (capitão and Schinopsis brasiliensis (braúna] and three solutions simulating leachate compound (atrazine, 2,4-D and water - control, with four replicates each. The characteristics measured were plant height, stem diameter, number of leaves, leaf area and dry biomass, and foliar nutrition. Forest species survived the herbicide application, and most showed an increase in macronutrients even under an herbicide application, and the Inga had the highest tolerance regarding growth analysis. It is recommended to use species that are more tolerant to Atrazine and 2,4-D in field experiments to confirm previous results of this simulation.

  16. Herbicide and fertilizers promote analogous phylogenetic responses but opposite functional responses in plant communities

    International Nuclear Information System (INIS)

    Pellissier, Loïc; Wisz, Mary S; Strandberg, Beate; Damgaard, Christian

    2014-01-01

    Throughout the world, herbicides and fertilizers change species composition in agricultural communities, but how do the cumulative effects of these chemicals impact the functional and phylogenetic structure of non-targeted communities when they drift into adjacent semi-natural habitats? Based on long-term experiment we show that fertilizer and herbicides (glyphosate) have contrasting effects on functional structure, but can increase phylogenetic diversity in semi-natural plant communities. We found that an increase in nitrogen promoted an increase in the average specific leaf area and canopy height at the community level, but an increase in glyphosate promoted a decrease in those traits. Phylogenetic diversity of plant communities increased when herbicide and fertilizer were applied together, likely because functional traits facilitating plant success in those conditions were not phylogenetically conserved. Species richness also decreased with increasing levels of nitrogen and glyphosate. Our results suggest that predicting the cumulative effects of agrochemicals is more complex than anticipated due to their distinct selection of traits that may or may not be conserved phylogenetically. Precautionary efforts to mitigate drift of agricultural chemicals into semi-natural habitats are warranted to prevent unforeseeable biodiversity shifts. (paper)

  17. Inheritance and mechanism of resistance to herbicides inhibiting acetolactate synthase in Sonchus oleraceus L.

    Science.gov (United States)

    Boutsalis, P; Powles, S B

    1995-07-01

    A biotype of Sonchus oleraceus L. (Compositae) has developed resistance to herbicides inhibiting acetolactate synthase (ALS) following field selection with chlorsulfuron for 8 consecutive years. The aim of this study was to determine the inheritance and mechanism of resistance in this biotype. Determination of ALS activity and inhibition kinetics revealed that Km and Vmax did not vary greatly between the resistant and susceptible biotypes. ALS extracted from the resistant biotype was resistant to five ALS-inhibiting herbicides in an in vitro assay. ALS activity from the resistant biotype was 14 19, 2, 3 and 3 times more resistant to inhibition by chlorsulfuron, sulfometuron, imazethapyr, imazapyr and flumetsulam, respectively, than the susceptible biotype. Hybrids between the resistant and a susceptible biotype were produced, and inheritance was followed through the F1, F2 and F3 generations. F1 hybrids displayed a uniform intermediate level of resistance between resistant and susceptible parents. Three distinct phenotypes, resistant, intermediate and susceptible, were identified in the F2 generation following chlorsulfuron application. A segregation ratio of 1∶2∶1 was observed, indicative of the action of a single, nuclear, incompletely dominant gene. F3 families, derived from intermediate F2 individuals, segregated in a similar manner. Resistance to herbicides inhibiting ALS in this biotype of S. oleraceus is due to the effect of a single gene coding for a resistant form of the target enzyme, ALS.

  18. Sarmentine, a natural herbicide from Piper species with multiple herbicide mechanisms of action

    Directory of Open Access Journals (Sweden)

    Franck Emmanuel Dayan

    2015-04-01

    Full Text Available Sarmentine, 1-(1-pyrrolidinyl-(2E,4E-2,4-decadien-1-one, is a natural amide isolated from the fruits of Piper species. The compound has a number of interesting biological properties, including its broad-spectrum activity on weeds as a contact herbicide. Initial studies highlighted a similarity in response between plants treated with sarmentine and herbicidal soaps such as pelargonic acid (nonanoic acid. However, little was known about the mechanism of action leading to the rapid desiccation of foliage treated by sarmentine. In cucumber cotyledon disc-assays, sarmentine induced rapid light-independent loss of membrane integrity at 100 µM or higher concentration, whereas 3 mM pelargonic acid was required for a similar effect. Sarmentine was between 10 and 30 times more active than pelargonic acid on wild mustard, velvetleaf, redroot pigweed and crabgrass. Additionally, the potency of 30 µM sarmentine was greatly stimulated by light, suggesting that this natural product may also interfere with photosynthetic processes. This was confirmed by observing a complete inhibition of photosynthetic electron transport at that concentration. Sarmentine also acted as an inhibitor of photosystem II on isolated thylakoid membranes by competing for the binding site of plastoquinone. This can be attributed in part to structural similarities between herbicides like sarmentine and diuron. While this mechanism of action accounts for the light stimulation of the activity of sarmentine, it does not account for its ability to destabilize membranes in darkness. In this respect, sarmentine has some structural similarity to crotonoyl-CoA, the substrate of enoyl-ACP reductase, a key enzyme in the early steps of fatty acid synthesis. Inhibitors of this enzyme, such as triclosan, cause rapid loss of membrane integrity in the dark. Sarmentine inhibited the activity of enoyl-ACP reductase, with an I50app of 18.3 µM. Therefore, the herbicidal activity of sarmentine appears to

  19. Sorption of Pharmaceuticals, Heavy Metals, and Herbicides to Biochar in the Presence of Biosolids.

    Science.gov (United States)

    Bair, Daniel A; Mukome, Fungai N D; Popova, Inna E; Ogunyoku, Temitope A; Jefferson, Allie; Wang, Daoyuan; Hafner, Sarah C; Young, Thomas M; Parikh, Sanjai J

    2016-11-01

    Agricultural practices are increasingly incorporating recycled waste materials, such as biosolids, to provide plant nutrients and enhance soil functions. Although biosolids provide benefits to soil, municipal wastewater treatment plants receive pharmaceuticals and heavy metals that can accumulate in biosolids, and land application of biosolids can transfer these contaminants to the soil. Environmental exposure of these contaminants may adversely affect wildlife, disrupt microbial communities, detrimentally affect human health through long-term exposure, and cause the proliferation of antibiotic-resistant bacteria. This study considers the use of biochar co-amendments as sorbents for contaminants from biosolids. The sorption of pharmaceuticals (ciprofloxacin, triclocarban, triclosan), and heavy metals (Cu, Cd, Ni, Pb) to biochars and biochar-biosolids-soil mixtures was examined. Phenylurea herbicide (monuron, diuron, linuron) sorption was also studied to determine the potential effect of biochar on soil-applied herbicides. A softwood (SW) biochar (510°C) and a walnut shell (WN) biochar (900°C) were used as contrasting biochars to highlight potential differences in biochar reactivity. Kaolinite and activated carbon served as mineral and organic controls. Greater sorption for almost all contaminants was observed with WN biochar over SW biochar. The addition of biosolids decreased sorption of herbicides to SW biochar, whereas there was no observable change with WN biochar. The WN biochar showed potential for reducing agrochemical and contaminant transport but may inhibit the efficacy of soil-applied herbicides. This study provides support for minimizing contaminant mobility from biosolids using biochar as a co-amendment and highlights the importance of tailoring biochars for specific characteristics through feedstock selection and pyrolysis-gasification conditions. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science

  20. Effects of the herbicide glyphosate on non-target plant native species from Chaco forest (Argentina).

    Science.gov (United States)

    Florencia, Ferreira María; Carolina, Torres; Enzo, Bracamonte; Leonardo, Galetto

    2017-10-01

    Agriculture based on transgenic crops has expanded in Argentina into areas formerly occupied by Chaco forest. Even though glyphosate is the herbicide most widely used in the world, increasing evidence indicates severe ecotoxicological effects on non-target organisms as native plants. The aim of this work is to determine glyphosate effects on 23 native species present in the remaining Chaco forests immersed in agricultural matrices. This is a laboratory/greenhouse approach studying acute effects on seedlings after 21 days. A gradient of glyphosate rates (525, 1050, 2100, 4200, and 8400g ai/Ha; recommended field application rate (RFAR) = 2100g ai/Ha) was applied on four-week seedlings cultivated in a greenhouse and response variables (phytotoxicity, growth reduction, and sensitivity to the herbicide) were measured. This gradient of herbicide rates covers realistic rates of glyphosate applications in the crop field and also those that can reach vegetation of forest relicts by off-target drift and overspray. Testing was performed following guidelines for vegetative vigour (post-germination spray). All species showed lethal or sublethal effects after the application of the 25% of RFAR (50% of species showed severe phytotoxicity or death and 70% of species showed growth reduction). The results showed a gradient of sensitivity to glyphosate by which some of the studied species are very sensitive to glyphosate and seedlings died with 25% of RFAR while other species can be classified as herbicide-tolerant. Thus, the vegetation present in the forest relicts could be strongly affected by glyphosate application on crops. Lethal and sublethal effects of glyphosate on non-target plants could promote both the loss of biodiversity in native forest relicts immersed in the agroecosystems and the selection of new crop weeds considering that some biotypes are continuously exposed to low doses of glyphosate. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Herbicide Glyphosate Impact to Earthworm (E. fetida

    Directory of Open Access Journals (Sweden)

    Greta Dajoraitė

    2016-10-01

    Full Text Available Glyphosate is a broad spectrum weed resistant herbicide. Glyphosate may pose negative impact on land ecosystems because of wide broad usage and hydrofilic characteristic. The aim of this study was to investigate negative effects of glyphosate on soil invertebrate organisms (earthworm Eisenia fetida. The duration of experiment was 8 weeks. The range of the test concentrations of glyphosate were: 0,1, 1, 5, 10, 20 mg/kg. To investigate the glyphosate impact on earthworm Eisenia fetida the following endpoints were measured: survival, reproduction and weight. The exposure to 20 mg/kg glyphosate has led to the 100% mortality of earthworms. Glyphosate has led to decreased E. fetida reproduction, the cocoons were observed only in the lowest concentration (0,1 mg/kg. In general: long-term glyphosate toxicity to earthworms (E. fetida may be significant.

  2. Dinitroaniline herbicide resistance and the microtubule cytoskeleton.

    Science.gov (United States)

    Anthony; Hussey

    1999-03-01

    Dinitroaniline herbicides have been used for pre-emergence weed control for the past 25 years in cotton, soybean, wheat and oilseed crops. Considering their long persistence and extensive use, resistance to dinitroanilines is fairly rare. However, the most widespread dinitroaniline-resistant weeds, the highly resistant (R) and the intermediate (I) biotypes of the invasive goosegrass Eleusine indica, are now infesting more than 1000 cotton fields in the southern states of the USA. The molecular basis of this resistance has been identified, and found to be a point mutation in a major microtubule cytoskeletal protein, alpha-tubulin. These studies have served both to explain the establishment of resistance and to reveal fundamental properties of tubulin gene expression and microtubule structure.

  3. Evaluating the Hydrologic Performance of Low Impact Development Scenarios in a Micro Urban Catchment

    Science.gov (United States)

    Li, Chunlin; Liu, Miao; Hu, Yuanman; Han, Rongqing; Shi, Tuo; Qu, Xiuqi; Wu, Yilin

    2018-01-01

    As urbanization progresses, increasingly impervious surfaces have changed the hydrological processes in cities and resulted in a major challenge for urban stormwater control. This study uses the urban stormwater model to evaluate the performance and costs of low impact development (LID) scenarios in a micro urban catchment. Rainfall-runoff data of three rainfall events were used for model calibration and validation. The pre-developed (PreDev) scenario, post-developed (PostDev) scenario, and three LID scenarios were used to evaluate the hydrologic performance of LID measures. Using reduction in annual runoff as the goal, the best solutions for each LID scenario were selected using cost-effectiveness curves. The simulation results indicated that the three designed LID scenarios could effectively reduce annual runoff volumes and pollutant loads compared with the PostDev scenario. The most effective scenario (MaxPerf) reduced annual runoff by 53.4%, followed by the sponge city (SpoPerf, 51.5%) and economy scenarios (EcoPerf, 43.1%). The runoff control efficiency of the MaxPerf and SpoPerf scenarios increased by 23.9% and 19.5%, respectively, when compared with the EcoPerf scenario; however, the costs increased by 104% and 83.6%. The reduction rates of four pollutants (TSS, TN, TP, and COD) under the MaxPerf scenario were 59.8–61.1%, followed by SpoPerf (53.9–58.3%) and EcoPerf (42.3–45.4%), and the costs of the three scenarios were 3.74, 3.47 and 1.83 million yuan, respectively. These results can provide guidance to urban stormwater managers in future urban planning to improve urban water security. PMID:29401747

  4. Use of impact fees to incentivize low-impact development and promote compact growth.

    Science.gov (United States)

    Lu, Zhongming; Noonan, Douglas; Crittenden, John; Jeong, Hyunju; Wang, Dali

    2013-10-01

    Low-impact development (LID) is an innovative stormwater management strategy that restores the predevelopment hydrology to prevent increased stormwater runoff from land development. Integrating LID into residential subdivisions and increasing population density by building more compact living spaces (e.g., apartment homes) can result in a more sustainable city by reducing stormwater runoff, saving infrastructural cost, increasing the number of affordable homes, and supporting public transportation. We develop an agent-based model (ABM) that describes the interactions between several decision-makers (i.e., local government, a developer, and homebuyers) and fiscal drivers (e.g., property taxes, impact fees). The model simulates the development of nine square miles of greenfield land. A more sustainable development (MSD) scenario introduces an impact fee that developers must pay if they choose not to use LID to build houses or apartment homes. Model simulations show homeowners selecting apartment homes 60% or 35% of the time after 30 years of development in MSD or business as usual (BAU) scenarios, respectively. The increased adoption of apartment homes results from the lower cost of using LID and improved quality of life for apartment homes relative to single-family homes. The MSD scenario generates more tax revenue and water savings than does BAU. A time-dependent global sensitivity analysis quantifies the importance of socioeconomic variables on the adoption rate of apartment homes. The top influential factors are the annual pay rates (or capital recovery factor) for single-family houses and apartment homes. The ABM can be used by city managers and policymakers for scenario exploration in accordance with local conditions to evaluate the effectiveness of impact fees and other policies in promoting LID and compact growth.

  5. Efficacy and economics of different herbicides in aerobic rice system

    African Journals Online (AJOL)

    Jane

    2011-08-03

    Aug 3, 2011 ... options for effective and economic weed control in rice under aerobic system ... constraint to aerobic rice production and therefore, ... Herbicide has become an attractive alternative to manual ... MATERIALS AND METHODS.

  6. Herbicides effect on the nitrogen fertilizer assimilation by sensitive plants

    International Nuclear Information System (INIS)

    Ladonin, V.F.; Samojlov, L.N.

    1976-01-01

    It has been established in studying the effect of herbicides on pea plants that the penetration of the preparations into the tissues of leaves and stems results in a slight increase of the rate of formation of dry substance in the leaves of the treated plants within 24 hours after treatment as compared with control, whereas in the last period of the analysis the herbicides strongly inhibit the formation of dry substance in leaves. The applied herbicide doses have resulted in drastic changes of the distribution of the plant-assimilated nitrogen between the protein and non-protein fractions in the leaves and stems of pea. When affected by the studied herbicides, the fertilizer nitrogen supply to the pea plants changes and the rate of the fertilizer nitrogen assimilation by the plants varies noticeably. The regularities of the fertilizer nitrogen inclusion in the protein and non-protein nitrogen compounds of the above-ground pea organs have been studied

  7. Biodegradation of acetanilide herbicides acetochlor and butachlor in soil.

    Science.gov (United States)

    Ye, Chang-ming; Wang, Xing-jun; Zheng, He-hui

    2002-10-01

    The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matter addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soil-SDBS mixtures and soil-HA mixtures were 4.6 d, 6.1 d and 5.4 d and 5.3 d, 4.9 d and 5.3 d respectively. The biodegradation products were hydroxyacetochlor and 2-methyl-6-ethylaniline for acetochlor, and hydroxybutachlor and 2,6-diethylaniline for butachlor.

  8. Biodegradation of glyphosate herbicide in vitro using bacterial ...

    African Journals Online (AJOL)

    USER

    2010-06-28

    Jun 28, 2010 ... Full Length Research Paper ... Glyphosate is a compound used as herbicide in the control and/or killing of grasses and herbaceous plants. ... Because of its toxicity to non-target organisms, there is need to decontaminate.

  9. Transgenic rice expressing a codon-modified synthetic CP4-EPSPS confers tolerance to broad-spectrum herbicide, glyphosate.

    Science.gov (United States)

    Chhapekar, Sushil; Raghavendrarao, Sanagala; Pavan, Gadamchetty; Ramakrishna, Chopperla; Singh, Vivek Kumar; Phanindra, Mullapudi Lakshmi Venkata; Dhandapani, Gurusamy; Sreevathsa, Rohini; Ananda Kumar, Polumetla

    2015-05-01

    Highly tolerant herbicide-resistant transgenic rice was developed by expressing codon-modified synthetic CP4--EPSPS. The transformants could tolerate up to 1% commercial glyphosate and has the potential to be used for DSR (direct-seeded rice). Weed infestation is one of the major biotic stress factors that is responsible for yield loss in direct-seeded rice (DSR). Herbicide-resistant rice has potential to improve the efficiency of weed management under DSR. Hence, the popular indica rice cultivar IR64, was genetically modified using Agrobacterium-mediated transformation with a codon-optimized CP4-EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) gene, with N-terminal chloroplast targeting peptide from Petunia hybrida. Integration of the transgenes in the selected rice plants was confirmed by Southern hybridization and expression by Northern and herbicide tolerance assays. Transgenic plants showed EPSPS enzyme activity even at high concentrations of glyphosate, compared to untransformed control plants. T0, T1 and T2 lines were tested by herbicide bioassay and it was confirmed that the transgenic rice could tolerate up to 1% of commercial Roundup, which is five times more in dose used to kill weeds under field condition. All together, the transgenic rice plants developed in the present study could be used efficiently to overcome weed menace.

  10. Enrichment and molecular characterization of a bacterial culture that degrades methoxy-methyl urea herbicides and their aniline derivatives.

    Science.gov (United States)

    El-Fantroussi, S; Verstraete, W; Top, E M

    2000-12-01

    Soil treated with linuron for more than 10 years showed high biodegradation activity towards methoxy-methyl urea herbicides. Untreated control soil samples taken from the same location did not express any linuron degradation activity, even after 40 days of incubation. Hence, the occurrence in the field of a microbiota having the capacity to degrade a specific herbicide was related to the long-term treatment of the soil. The enrichment culture isolated from treated soil showed specific degradation activity towards methoxy-methyl urea herbicides, such as linuron and metobromuron, while dimethyl urea herbicides, such as diuron, chlorotoluron, and isoproturon, were not transformed. The putative metabolic intermediates of linuron and metobromuron, the aniline derivatives 3, 4-dichloroaniline and 4-bromoaniline, were also degraded. The temperature of incubation drastically affected degradation of the aniline derivatives. Whereas linuron was transformed at 28 and 37 degrees C, 3,4-dichloroaniline was transformed only at 28 degrees C. Monitoring the enrichment process by reverse transcription-PCR and denaturing gradient gel electrophoresis (DGGE) showed that a mixture of bacterial species under adequate physiological conditions was required to completely transform linuron. This research indicates that for biodegradation of linuron, several years of adaptation have led to selection of a bacterial consortium capable of completely transforming linuron. Moreover, several of the putative species appear to be difficult to culture since they were detectable by DGGE but were not culturable on agar plates.

  11. Herbicidal treatments for control of Papaver somniferum L.

    Science.gov (United States)

    Horowitz, M

    1980-01-01

    Fifty-five commercially available herbicides were evaluated for possible use to destroy illicit opium poppy crops (Papaver somniferum). In the first stage, herbicides were sprayed on poppy plants grown in containers. The following compounds killed poppy plants: (a) herbicides with typical foliar activity--amitrole, bromoxynil, 2,4-D, glyphosate, ioxynil and paraquat; and (b) herbicides with root and foliar activity--the triazines ametryn, atrazine, metribuzin, prometryn, simazine and terbutryn; the substituted ureas benzthiazuron, chloroxuron, diuron, fluometuron, linuron, methabenzthiazuron, neburon and phenobenzuron; and the miscellaneous compounds karbutilate, methazole, oxadiazon and pyrazon. Severe but sublethal injury was caused by cycloate, EPTC, molinate, pobulate, cacodylate + MSMA, ethofumesate, perfluidone and phenmedipham. Abnormal development of vegetative or reproductive parts of the plant was induced by benefin, butralin, dinitramine, pendimethalin, trifluralin, diphenamid, napropamide, dalapon and propham. Efficient herbicides with negligible persistence in soil at the doses applied were evaluated on poppy plants in the field at various stages of growth. Small plants were severely injured by 2,4-D, killed rapidly by bromoxynil, ioxynil, paraquat (in mixture + diquat), and more slowly by glyphosate and metribuzin. The resistance to herbicides increased with the age of the poppy plant. Severe damage with partial kill of developed plants was obtained with bromoxynil, ioxynil, glyphosate, and paraquat + diquat; the last treatment produced the fastest effect.

  12. Herbicides: A new threat to the Great Barrier Reef

    International Nuclear Information System (INIS)

    Lewis, Stephen E.; Brodie, Jon E.; Bainbridge, Zoe T.; Rohde, Ken W.; Davis, Aaron M.; Masters, Bronwyn L.; Maughan, Mirjam; Devlin, Michelle J.; Mueller, Jochen F.; Schaffelke, Britta

    2009-01-01

    The runoff of pesticides (insecticides, herbicides and fungicides) from agricultural lands is a key concern for the health of the iconic Great Barrier Reef, Australia. Relatively low levels of herbicide residues can reduce the productivity of marine plants and corals. However, the risk of these residues to Great Barrier Reef ecosystems has been poorly quantified due to a lack of large-scale datasets. Here we present results of a study tracing pesticide residues from rivers and creeks in three catchment regions to the adjacent marine environment. Several pesticides (mainly herbicides) were detected in both freshwater and coastal marine waters and were attributed to specific land uses in the catchment. Elevated herbicide concentrations were particularly associated with sugar cane cultivation in the adjacent catchment. We demonstrate that herbicides reach the Great Barrier Reef lagoon and may disturb sensitive marine ecosystems already affected by other pressures such as climate change. - Herbicide residues have been detected in Great Barrier Reef catchment waterways and river water plumes which may affect marine ecosystems.

  13. Antioxidant activity of rice plants sprayed with herbicides

    Directory of Open Access Journals (Sweden)

    Marcos André Nohatto

    2016-03-01

    Full Text Available Understanding the physiological defense behavior of plants subjected to herbicide application may help to identify products with higher or lower capacity to cause oxidative stress in crops. This study aimed at evaluating the effect of herbicides in the antioxidant activity of rice plants. The experimental design was completely randomized, with six replications. Treatments consisted of the herbicides bentazon (photosystem II inhibitor; 960 g ha-1, penoxsulam (acetolactate synthase inhibitor; 60 g ha-1, cyhalofop-butyl (acetyl coenzyme-A carboxylase inhibitor; 315 g ha-1 and a control. After the herbicides application, samples of rice shoots were collected at 12, 24, 48 and 96 hours after application (HAA. The components evaluated were hydrogen peroxide (H2O2, lipid peroxidation and activity of the antioxidant enzymes superoxide dismutase (SOD and catalase (CAT. Bentazon (up to 24 HAA and penoxsulam (48 and 96 HAA reduced the CAT activity. Moreover, these herbicides increased the levels of H2O2, lipid peroxidation and SOD activity, indicating a condition of oxidative stress in rice plants. The cyhalofop-butyl herbicide did not alter the antioxidant activity, showing that it causes less stress to the crop.

  14. Environmental and health effects of the herbicide glyphosate.

    Science.gov (United States)

    Van Bruggen, A H C; He, M M; Shin, K; Mai, V; Jeong, K C; Finckh, M R; Morris, J G

    2018-03-01

    The herbicide glyphosate, N-(phosphonomethyl) glycine, has been used extensively in the past 40years, under the assumption that side effects were minimal. However, in recent years, concerns have increased worldwide about the potential wide ranging direct and indirect health effects of the large scale use of glyphosate. In 2015, the World Health Organization reclassified glyphosate as probably carcinogenic to humans. A detailed overview is given of the scientific literature on the movement and residues of glyphosate and its breakdown product aminomethyl phosphonic acid (AMPA) in soil and water, their toxicity to macro- and microorganisms, their effects on microbial compositions and potential indirect effects on plant, animal and human health. Although the acute toxic effects of glyphosate and AMPA on mammals are low, there are animal data raising the possibility of health effects associated with chronic, ultra-low doses related to accumulation of these compounds in the environment. Intensive glyphosate use has led to the selection of glyphosate-resistant weeds and microorganisms. Shifts in microbial compositions due to selective pressure by glyphosate may have contributed to the proliferation of plant and animal pathogens. Research on a link between glyphosate and antibiotic resistance is still scarce but we hypothesize that the selection pressure for glyphosate-resistance in bacteria could lead to shifts in microbiome composition and increases in antibiotic resistance to clinically important antimicrobial agents. We recommend interdisciplinary research on the associations between low level chronic glyphosate exposure, distortions in microbial communities, expansion of antibiotic resistance and the emergence of animal, human and plant diseases. Independent research is needed to revisit the tolerance thresholds for glyphosate residues in water, food and animal feed taking all possible health risks into account. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Aquatic Plant Control Research Program: Aquatic Plant Identification and Herbicide Use Guide. Volume 2. Aquatic Plants and Susceptibility to Herbicides

    Science.gov (United States)

    1988-11-01

    Chronic >0.5 Daphnia Repeat exposure Chronic >0.2 reproduction 0 NOTE; Fluridone was not found to cause genetic mutations or cancer in tested lab...persists. REGISTERED HERBICIDES 95 REGISTERED HERBICIDES GLYPHOSATE A. Chemical Name and Formulation: Chemical name: N-(phosphonomethyl)glycine Formulation...RODEO (53.5% ai, isopropylamine salt of glyphosate , liquid) B. Mode of Action: Not definite. However, investigators have postulated that

  16. Regularity of mitosis in different varieties of winter bread wheat under the action of herbicides

    Directory of Open Access Journals (Sweden)

    Tatyana Eugenivna KOPYTCHUK

    2012-05-01

    Full Text Available The influence of the most widespread herbicides on winter wheat in Ukraine was studied by anaphase test. Treatment with herbicides reduced the germination of the seeds and disturbed the regularity of mitosis in all varieties of wheat. The range of violations of mitosis was demonstrated by the formation of chromosomal aberrations and dysfunctions of cell cytoskeleton which occurred while processing herbicides. Varietal differences between investigated wheat by sensitivity to herbicides were discovered. The most resistant to herbicides was variety Fantasya Odesskaya, and the most sensitive – Nikoniya, while the most harmful herbicide for wheat was Napalm.

  17. Soil microbial and faunal responses to herbicide tolerant maize and herbicide in two soils

    DEFF Research Database (Denmark)

    Griffiths, Bryan; Caul, Sandra; Thompson, J.

    2008-01-01

    using a tiered approach at laboratory, glasshouse and field scales. Soil for the experiment was taken from field sites where the same maize cultivars were grown to allow comparison between results under glasshouse and field conditions. The maize cultivars T25 (GM HT glufosinate-ammonium tolerant....... The main effects on all measured parameters were those of soil type and plant growth stage, with four categories of subsequent interaction: (1) there were no effects of herbicide on plant growth or soil microarthropods: (2) the maize cultivar (but not the GM HT trait) had effects on the decomposition...

  18. Herbicides interfere with antigrazer defenses in Scenedesmus obliquus.

    Science.gov (United States)

    Zhu, Xuexia; Sun, Yunfei; Zhang, Xingxing; Heng, Hailu; Nan, Haihong; Zhang, Lu; Huang, Yuan; Yang, Zhou

    2016-11-01

    The extensive application of herbicides has led to a serious threat of herbicide contamination to aquatic ecosystem. Herbicide exposure affects aquatic communities not only by exerting toxicity on single species but also by changing interspecific interactions. This study investigated the antigrazer defenses of the common green alga Scenedesmus obliquus against different herbicides [glyphosate, 2,4-dichlorophenoxyacetic acid (2,4-D), and atrazine] at various concentrations (0-2.0 mg L(-1)). In the presence of grazer (Daphnia)-derived cues, S. obliquus populations without herbicides formed high proportions of multicelled (e.g., four- and eight-celled) colonies. This result confirms that S. obliquus exhibits a morphological defense against grazing risk. At the low concentration range of 0.002-0.02 mg L(-1), the three herbicides exerted no influence on the growth and photosynthetic efficiency of S. obliquus, and multicelled colonies showed constant proportions. At the high concentration range of 0.20-2.0 mg L(-1), atrazine significantly inhibited the algal growth and photosynthesis whereas glyphosate or 2,4-D did not. Nonetheless, these levels of glyphosate or 2,4-D remarkably decreased the proportion of multicelled colonies, with reduced numbers of cells per particle in Daphnia filtrate-treated population. No eight-celled colony was formed after treatment with atrazine at 0.20-2.0 mg L(-1) despite the addition of Daphnia filtrate. These results suggest that herbicide exposure impairs antigrazer colonial morphs in phytoplankton although it is not sufficient to hamper algal growth. This phenomenon can increase the risk of predation by herbivores, thereby disrupting the inducible phytoplankton community. Furthermore, the predator-prey interactions between herbivores and phytoplankton can be potentially changed more seriously than previously considered. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Efficacité de quelques herbicides des céréales dans une culture du blé tendre conduite en semis direct

    Directory of Open Access Journals (Sweden)

    Badr HAJJAJ

    2016-12-01

    Full Text Available In order to evaluate the efficacy of 11 cereal herbicides on no till soft wheat, two trials were conducted in Chaouia region during 2014-2015 growing season. Dominant species of weed flora in Sidi El Aidi site were: Bromus rigidus, Lolium rigidum and Avena sterilis. Dominant species of weed flora in Ouled Said site were: Avena sterilis, Centaurea diluta and Papaver rhoeas. The obtained results showed that “Pyroxsulam” and “Mesosulfuron Sodium + Iodosulfuron sodium” gavethe best efficacy on rip gut brome. Prosulfocarb provided excellent control of ryegrass but no effect on ripgut brome or wild oat. Broadleaf herbicides provided moderate to good control. “Mesosulfuron Sodium +Iodosulfuron sodium” need to be completed with an broadleaf herbicide in case centaurea diluta is present. “Pyroxsulam” need to be tank mixed with a broadleaf herbicide to widen its weeds spectrum. Treatment with “Pendimethalin”as pre-emergence herbicide allowed an early complete control of weeds and good crop selectivity.

  20. Effects of fertilizers, fungicides and herbicides on the fate of 14C-parathion and 14C-fonofos in soils and crops

    International Nuclear Information System (INIS)

    Lichtenstein, E.P.; Ferris, I.; Liang, T.T.; Koeppe, M.

    1983-01-01

    The fate of 14 C-parathion and 14 C-fonofos in soil is significantly affected by the presence of organic and inorganic fertilizers, fungicides and herbicides, possibly via the effect of soil microflora. Soil microorganisms are responsible for the oxidative as well as the reductive degradation of the insecticide. Using 14 carbon, the authors studied the effects of selected fungicides (benlate, captafol and manzate) herbicides (2,4-D parathion) and fertilizers ((NH 4 ) 6 SO 4 , KNO 3 , urea) on pesticides in Cromberry soils. Results of the study stress the importance of investigating the environmental fate of a particular pesticide in relation to the presence of the agricultural chemicals

  1. Subcritical water extraction combined with molecular imprinting technology for sample preparation in the detection of triazine herbicides.

    Science.gov (United States)

    Zhao, Fengnian; Wang, Shanshan; She, Yongxin; Zhang, Chao; Zheng, Lufei; Jin, Maojun; Shao, Hua; Jin, Fen; Du, Xinwei; Wang, Jing

    2017-09-15

    A selective, environmentally friendly, and cost-effective sample extraction method based on a combination of subcritical water extraction (SWE) and molecularly imprinted solid-phase extraction (MISPE) was developed for the determination of eight triazine herbicides in soil samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In SWE, the highest extraction yields of triazine herbicides were obtained under 150°C for 15min using 20% ethanol as the organic modifier. Addition of MIP during SWE increased the extraction efficiency, and using MIP as a selective SPE sorbent improved the enrichment capability. Soil samples were treated with the optimized extraction MIP/SWE-MISPE method and analyzed by LC-MS/MS. The novel technique was then applied to soil samples for the determination of triazine herbicides, and better recoveries (78.9%-101%) were obtained compared with using SWE-MISPE (30%-67%). Moreover, this newly developed method displayed good linearity (R 2 >0.99) and precision (2.7-9.8%), and low enough detection limits (0.4-3.3μgkg -1 ). This combination of SWE and MIP technology is a simple, effective and promising method to selectively extract class-specific compounds in complex samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Weed infestation of a winter wheat canopy under the conditions of application of different herbicide doses and foliar fertilization

    Directory of Open Access Journals (Sweden)

    Piotr Kraska

    2012-12-01

    Full Text Available The present study was carried out in the years 2006-2008 in the Bezek Experimental Farm (University of Life Sciences in Lublin. A two-factor field experiment was set up according to a randomized block design, in three replications. The experimental field was situated on medium heavy mixed rendzina developed from chalk rock with medium dusty loam granulometric composition. The soil was characterised by neutral pH, a very high content of P (342.1 and K (278.9 along with a very low level of magnesium (16.0 mg × kg-1 of soil and organic carbon (over 3.5%. The aim of this research was to compare the effect of three herbicide doses and two foliar fertilizers applied in a winter wheat canopy on weed infestation. The herbicides Mustang 306 SE 0.4 l × ha-1 and Attribut 70 WG 60 g × ha-1 were applied at full recommended doses as well as at doses reduced to 75% and 50%. Foliar fertilizers Insol 3 (1 1 × ha-1 and FoliCare (20 kg × ha-1 were applied at full recommended doses twice in the growing season BBCH* development stage 23-25* and 33-35*. The control was not treated with the herbicides and foliar fertilizers. The weed infestation level was determined by means of the quantitative gravimetric method at two dates: the first one 6 weeks after herbicide application and the second one - before harvest. The number of weed individuals was counted; species composition and air-dry biomass of aboveground parts were estimated from randomly selected areas of 1 m × 0.25 m at four sites on each plot. Galium aparine and Apera spica-venti plants were sampled for molecular analysis 6 weeks after herbicide application (the treatments with the full herbicide dose, a 50% dose and the control without herbicides. The density of weeds and weed air-dry weight were statistically analysed by means of variance analysis, and the mean values were estimated with Tukey's confidence intervals (p=0.05. It was found that the number of weeds and air-dry weight of weeds in the

  3. Effects of the herbicide imazapyr on juvenile Oregon spotted frogs

    Science.gov (United States)

    Yahnke, Amy E.; Grue, Christian E.; Hayes, Marc P.; Troiano, Alexandra T.

    2013-01-01

    Conflict between native amphibians and aquatic weed management in the Pacific Northwest is rarely recognized because most native stillwater-breeding amphibian species move upland during summer, when herbicide application to control weeds in aquatic habitats typically occurs. However, aquatic weed management may pose a risk for aquatic species present in wetlands through the summer, such as the Oregon spotted frog (OSF, Rana pretiosa), a state endangered species in Washington. Acute toxicity of herbicides used to control aquatic weeds tends to be low, but the direct effects of herbicide tank mixes on OSFs have remained unexamined. We exposed juvenile OSFs to tank mixes of the herbicide imazapyr, a surfactant, and a marker dye in a 96-h static-renewal test. The tank mix was chosen because of its low toxicity to fish and its effectiveness in aquatic weed control. Concentrations were those associated with low-volume (3.5 L/ha) and high-volume (7.0 L/ha) applications of imazapyr and a clean-water control. Following exposure, frogs were reared for two months in clean water to identify potential latent effects on growth. Endpoints evaluated included feeding behavior, growth, and body and liver condition indices. We recorded no mortalities and found no significant differences for any end point between the herbicide-exposed and clean-water control frogs. The results suggest that imazapyr use in wetland restoration poses a low risk of direct toxic effects on juvenile OSFs.

  4. Combined thermal and herbicide stress in functionally diverse coral symbionts

    International Nuclear Information System (INIS)

    Dam, J.W. van; Uthicke, S.; Beltran, V.H.; Mueller, J.F.; Negri, A.P.

    2015-01-01

    Most reef building corals rely on symbiotic microalgae (genus Symbiodinium) to supply a substantial proportion of their energy requirements. Functional diversity of different Symbiodinium genotypes, endorsing the host with physiological advantages, has been widely reported. Yet, the influence of genotypic specificity on the symbiont's susceptibility to contaminants or cumulative stressors is unknown. Cultured Symbiodinium of presumed thermal-tolerant clade D tested especially vulnerable to the widespread herbicide diuron, suggesting important free-living populations may be at risk in areas subjected to terrestrial runoff. Co-exposure experiments where cultured Symbiodinium were exposed to diuron over a thermal stress gradient demonstrated how fast-growing clade C1 better maintained photosynthetic capability than clade D. The mixture toxicity model of Independent Action, considering combined thermal stress and herbicide contamination, revealed response additivity for inhibition of photosynthetic yield in both tested cultures, emphasizing the need to account for cumulative stressor impacts in ecological risk assessment and resource management. - Highlights: • Water quality influences thermal stress thresholds in different Symbiodinium types. • Photosystem of clade D tested more sensitive than C1 to a common herbicide. • Increased thermal tolerance quickly countered in presence of herbicide. • Mixture toxicity approach demonstrated response additivity for combined stressors. • Symbiotic partnership may be compromised in areas subjected to terrestrial runoff. - Thermal-tolerant Symbiodinium type D tested especially vulnerable to a common herbicide, emphasizing the significance of cumulative stressors in ecological risk management

  5. Cloud based, Open Source Software Application for Mitigating Herbicide Drift

    Science.gov (United States)

    Saraswat, D.; Scott, B.

    2014-12-01

    The spread of herbicide resistant weeds has resulted in the need for clearly marked fields. In response to this need, the University of Arkansas Cooperative Extension Service launched a program named Flag the Technology in 2011. This program uses color-coded flags as a visual alert of the herbicide trait technology within a farm field. The flag based program also serves to help avoid herbicide misapplication and prevent herbicide drift damage between fields with differing crop technologies. This program has been endorsed by Southern Weed Science Society of America and is attracting interest from across the USA, Canada, and Australia. However, flags have risk of misplacement or disappearance due to mischief or severe windstorms/thunderstorms, respectively. This presentation will discuss the design and development of a cloud-based, free application utilizing open-source technologies, called Flag the Technology Cloud (FTTCloud), for allowing agricultural stakeholders to color code their farm fields for indicating herbicide resistant technologies. The developed software utilizes modern web development practices, widely used design technologies, and basic geographic information system (GIS) based interactive interfaces for representing, color-coding, searching, and visualizing fields. This program has also been made compatible for a wider usability on different size devices- smartphones, tablets, desktops and laptops.

  6. Mucilage from seeds of chia (Salvia hispanica L.) used as soil conditioner; effects on the sorption-desorption of four herbicides in three different soils.

    Science.gov (United States)

    Di Marsico, A; Scrano, L; Amato, M; Gàmiz, B; Real, M; Cox, L

    2018-06-01

    The objective of this work was to determine the effect of the mucilage extracted from Chia seeds (Salvia hispanica L.) as soil amendment on soil physical properties and on the sorption-desorption behaviour of four herbicides (MCPA, Diuron, Clomazone and Terbuthylazine) used in cereal crops. Three soils of different texture (sandy-loam, loam and clay-loam) were selected, and mercury intrusion porosimetry and surface area analysis were used to examine changes in the microstructural characteristics caused by the reactions that occur between the mucilage and soil particles. Laboratory studies were conducted to characterise the selected herbicides with regard their sorption on tested soils added or not with the mucilage. Mucilage amendment resulted in a reduction in soil porosity, basically due to a reduction in larger pores (radius>10μm) and an important increase in finer pores (radius<10μm) and in partcles' surface. A higher herbicide sorption in the amended soils was ascertained when compared to unamended soils. The sorption percentage of herbicides in soils treated with mucilage increased in the order; sandy-loamherbicides was highly inhibited in the soils treated with mucilage; only Terbuthylazine showed a slight desorption in the case of loam and clay loam-soils. This study leads to the conclusion that mucilage from Chia seeds used as soil conditioner can reduce the mobility of herbicides tested in agricultural soils with different physico-chemical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Plant reproduction is altered by simulated herbicide drift to constructed plant communities

    Science.gov (United States)

    Herbicide drift may have unintended impacts on native vegetation, adversely affecting structure and function of plant communities. However, these potential effects have been rarely studied or quantified. To determine potential ecological effects of herbicide drift, we construct...

  8. Bioactivity of Several Herbicides on the Nanogram Level Under Different Soil Moisture Conditions.

    Science.gov (United States)

    Jung, S C; Kuk, Y I; Senseman, S A; Ahn, H G; Seong, C N; Lee, D J

    2015-01-01

    In this study, a double-tube centrifuge method was employed to determine the effects of soil moisture on the bioactivity of cafenstrole, pretilachlor, benfuresate, oxyfluorfen and simetryn. In general, the available herbicide concentration in soil solution (ACSS) showed little change as soil moisture increased for herbicides. The total available herbicide in soil solution (TASS) typically increased as soil moisture increased for all herbicides. The relationship between TASS and % growth rate based on dry weight showed strong linear relationships for both cafenstrole and pretilachlor, with r2 values of 0.95 and 0.84, respectively. Increasing TASS values were consistent with increasing herbicide water solubility, with the exception of the ionizable herbicide simetryn. Plant absorption and % growth rate exhibited a strong linear relationship with TASS. According to the results suggested that TASS was a better predictor of herbicidal bioactivity than ACSS for all herbicides under unsaturated soil moisture conditions.

  9. In vitro sensitivity of antagonistic Trichoderma atroviride to herbicides

    Directory of Open Access Journals (Sweden)

    Patricia Helena Santoro

    2014-04-01

    Full Text Available Trichoderma atroviride was tested in vitro for its sensitivity to different herbicides. The dosages tested were recommended dosage (RD, half dosage (½RD, and double dosage (2RD. Germination, colony-forming units (CFU, radial growth, and spore production were evaluated. Carfentrazone-ethyl and sulfentrazone inhibited the germination at RD and 2RD. A reduction in the CFU was observed for glufosinate-ammonium, atrazine, carfentrazone-ethyl, diuron + paraquat dichloride, imazapyr, oxyfluorfen, and sulfentrazone at each of the tested dosages. Radial growth was influenced by ametryn, atrazine, carfentrazone-ethyl, oxyfluorfen, and sulfentrazone herbicides, with an 80% reduction of the colonial area. Spore production was affected by carfentrazone-ethyl, oxyfluorfen, and sulfentrazone with colonial area reductions of over 70%. It was concluded that 2,4 D, clomazone, and imazapyr herbicides showed the least toxicity to T. atroviride and should be used in the crops where the fungus has been applied for phytopathogen control.

  10. Intraregional and inter-regional variability of herbicide sensitivity in common arable weed populations

    DEFF Research Database (Denmark)

    de Mol, Friederike; Gerowitt, Bärbel; Kaczmarek, Sylwia

    2015-01-01

    The question on intraregional versus inter-regional variability in herbicide sensitivity for weed populations is of major importance, both in extrapolation of model parameters and in herbicide zonal approval procedures. We hypothesised that inter-regional variability in herbicide sensitivity for ...

  11. Agricultural herbicide transport in a first-order intermittent stream, Nebraska, USA

    Science.gov (United States)

    Vogel, J.R.; Linard, J.I.

    2011-01-01

    The behavior of herbicides in surface waters is a function of many variables, including scale of the watershed, physical and chemical properties of the herbicide, physical and chemical properties of the soil, rainfall intensity, and time of year. In this study, the transport of 6 herbicides and 12 herbicide degradates was examined during the 2004 growing season in an intermediate-scale agricultural watershed (146 ha) that is drained by a first-order intermittent stream, and the mass load for each herbicide in the stream was estimated. The herbicide load during the first week of storm events after application ranged from 17% of annual load for trifluralin to 84% of annual load for acetochlor. The maximum weekly herbicide load in the stream was generally within the first 3 weeks after application for those compounds that were applied within the watershed during 2004, and later for herbicides not applied within the watershed during 2004 but still detected in the stream. The apparent dominant mode of herbicide transport in the stream-determined by analysis amongst herbicide and conservative ion concentrations at different points in the hydrograph and in base flow samples-was either overland runoff or shallow subsurface flow, depending on the elapsed time after application and type of herbicide. The load as a percentage of use (LAPU) for the parent compounds in this study was similar to literature values for those compounds applied by the farmer within the watershed, but smaller for those herbicides that had rainfall as their only source within the watershed.

  12. Transcript markers of herbicide stress in Arabidopsis and their cross-species extrapolation to Brassica

    Science.gov (United States)

    Low concentrations and short environmental persistence times of some herbicides make it difficult to develop analytical methods to detect herbicide residues in plants or soils. In contrast, genomics may provide tools to identify herbicide exposure to plants in field settings. Usi...

  13. The role of herbicides for enhancing productivity and conserving land for biodiversity in North America

    Science.gov (United States)

    Robert G. Wagner; Michael Newton; Elizabeth C. Cole; James H. Miller; Barry D. Shiver

    2004-01-01

    Herbicide technology has evolved with forest management in North America over the past 60 years and has become an integral part of modern forestry practice. Forest managers have prescribed herbicides to increase reforestation success and long-term timber yields. Wildlife managers and others interested in conserving biodi- versity, however, have often viewed herbicide...

  14. Using a Hydrological Model to Determine Environmentally Safer Windows for Herbicide Application

    Science.gov (United States)

    J.L. Michael; M.C. Smith; W.G. Knisel; D.G. Neary; W.P. Fowler; D.J. Turton

    1996-01-01

    A modification of the GLEAMS model was used to determine application windows which would optimise efficacy and environmental safety for herbicide application to a forest site. Herbicide/soil partition coefficients were determined using soil samples collected from the study site for two herbicides (imazapyr, Koc=46, triclopyr ester, K

  15. Effect of herbicides on photosynthetic electron transport and on the growth of the alga Scenedesmus quadricauda

    Directory of Open Access Journals (Sweden)

    W. Hendrich

    2015-01-01

    Full Text Available The inhibitory effect of herbicides on the Hill reaction (with 2,6-dichloro-phenol-indophenol as acceptor and their influence on development of the alga Scenedesmus quadricauda was studied. The following herbicides were tested: 2,4-D, Gramoxone, Afalon, Kresamone, CIPC and Simazine. The results are discussed in terms of the mechanism of action of the investigated herbicides.

  16. 75 FR 17857 - Removal of Obsolete References to Herbicides Containing Dioxin

    Science.gov (United States)

    2010-04-08

    ... Herbicides Containing Dioxin AGENCY: Department of Veterans Affairs. ACTION: Final rule. SUMMARY: The... health effects of exposure to herbicides containing dioxin and radiation to remove the obsolete references to herbicides containing dioxin. This final rule reflects changes made by the Agent Orange Act of...

  17. Low-Impact Space Weather Sensors and the U.S. National Security Spacecraft

    Science.gov (United States)

    2016-09-01

    for deep space missions), also needs to orient its solar arrays toward the sun, none of which can be accomplished without the ability to control the...Spacecraft Thermal Control Handbook: Cryogenics. El Segundo, CA: The Aerospace Press. ESA and NASA. 2015. “ Solar and Heliospheric Observatory Home Page...Distribution is unlimited. 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) Incorporating inexpensive low-impact targeted surface charging

  18. Vision for a low-impact renewable energy future for Canada

    International Nuclear Information System (INIS)

    2003-11-01

    The Clean Air Renewable Energy Coalition promotes the development of the renewable energy industry in Canada. The Coalition's vision for low-impact renewable energy focuses on green forms of electricity to provide not only light, heat and power, but to produce hydrogen fuel that could be used in fuel cell technologies. Low-impact renewable energy is a non-depleting resource with minimal environmental impacts. It includes wind energy, hydro energy, geothermal energy, biomass, tidal energy, and solar energy. The Coalition's goal is to have low-impact renewable energy account for at least 7 per cent of Canada's electricity production by 2010, and 15 per cent by 2020. It is currently at 1 per cent. This goal can be achieved by: defining a comprehensive renewable energy vision for Canada; setting long term targets for renewable energy in Canada; committing to a package of long term incentives; developing partnerships between all levels of government to increase financial investments in renewable energy projects; and, recognizing the potential for renewable energy in a carbon-constrained economy. refs., tabs

  19. Decision Support System for Optimized Herbicide Dose in Spring Barley

    DEFF Research Database (Denmark)

    Sønderskov, Mette; Kudsk, Per; Mathiassen, Solvejg K

    2014-01-01

    Crop Protection Online (CPO) is a decision support system, which integrates decision algorithms quantifying the requirement for weed control and a herbicide dose model. CPO was designed to be used by advisors and farmers to optimize the choice of herbicide and dose. The recommendations from CPO...... as the Treatment Frequency Index (TFI)) compared to a high level of required weed control. The observations indicated that the current level of weed control required is robust for a range of weed scenarios. Weed plant numbers 3 wk after spraying indicated that the growth of the weed species were inhibited...

  20. Oxidative stress induced by glyphosate-based herbicide on freshwater turtles.

    Science.gov (United States)

    Héritier, Laurent; Duval, David; Galinier, Richard; Meistertzheim, Anne-Leila; Verneau, Olivier

    2017-12-01

    Freshwater ecosystems face very strong anthropogenic pressures, among which overexploitation, habitat degradation, flow modification, species invasion, and water pollution lead to growing threats on biodiversity. Urbanization through wastewater treatment, industry through the release of inorganic and organic chemicals, and agriculture through the use of pesticides and herbicides are the main factors involved in water pollution. In France, more precisely in the Pyrénées-Orientales department, the poor quality of the watercourses is attributable overall to the use of glyphosate-based herbicides in agricultural activities. Because these chemicals can impact individuals, populations, and biodiversity, we investigated, under experimental conditions, the physiological response of animals facing abiotic contaminants. We selected as a model, juveniles of the freshwater turtle Trachemys scripta elegans. We measured the gene expression and activity of the catalase and superoxide dismutase enzymes as well as the levels of lipid peroxidation, which are all oxidative stress biomarkers, in turtles challenged with high concentrations of glyphosate-based herbicides, on the one hand, and with degraded waters collected from a local watercourse, on the other. We also measured the acetylcholinesterase activity across the same animals. We showed through variations in gene expression and enzyme activity that a glyphosate commercial formulation induced a stress in turtles. A similar outcome was obtained when turtles faced degraded waters. The results indicated that the poor quality of regional waters could be a real threat for animal health. Because turtles are globally less sensitive to contaminants than amphibians, which are lacking in the degraded waters of the Pyrénées-Orientales department, they could constitute an excellent model to follow the evolution of water quality through the study of oxidative stress biomarkers. Environ Toxicol Chem 2017;36:3343-3350. © 2017 SETAC.

  1. Development and evaluation of a gas chromatographic method for the determination of triazine herbicides in natural water samples

    Science.gov (United States)

    Steinheimer, T.R.; Brooks, M.G.

    1984-01-01

    A multi-residue method is described for the determination of triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0.1 ??g/L in a 1-litre sample. Three different natural water samples were used for error analysis via evaluation of recovery efficiencies and estimation of overall method precision. As an alternative to liquid-liquid partition (solvent extraction) for removal of compounds of interest from water, solid-phase extraction (SPE) techniques employing chromatographic grade silicas with chemically modified surfaces have been examined. SPE is found to provide rapid and efficient concentration with quantitative recovery of some triazine herbicides from natural water samples. Concentration factors of 500 to 1000 times are obtained readily by the SPE technique.A multi-residue method is described for the determination of triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0. 1 mu g/L in a 1-litre sample. As an alternative to liquid-liquid partition (solvent extraction) for removal of compounds of interest from water, solid-phase extraction (SPE) techniques employing chromatographic grade silicas with chemically modified surfaces have been examined. SPE is found to provide rapid and efficient concentration with quantitative recovery of some triazine herbicides from natural water samples. Concentration factors of 500 to 1000 times are obtained readily by the SPE technique.

  2. Potential use of soil-born fungi isolated from treated soil in Indonesia to degrade glyphosate herbicide

    Directory of Open Access Journals (Sweden)

    N. Arfarita

    2014-01-01

    Full Text Available The glyphosate herbicide is the most common herbicides used in palm-oil plantations and other agricultural in Indonesial. In 2020, Indonesian government to plan the development of oil palm plantations has reached 20 million hectares of which now have reached 6 million hectares. It means that a huge chemicals particularly glyphosate has been poured into the ground and continues to pollute the soil. However, there is no report regarding biodegradation of glyphosate-contaminated soils using fungal strain especially in Indonesia. This study was to observe the usage of Round Up as selection agent for isolation of soil-born fungi capable to grow on glyphosate as a sole source of phosphorus. Five fungal strains were able to grow consistently in the presence of glyphosate as the sole phosphorus source and identified as Aspergillus sp. strain KRP1, Fusarium sp. strain KRP2, Verticillium sp. strain KRP3, Acremoniumsp. strain GRP1 and Scopulariopsis sp. strain GRP2. This indicates as their capability to utilize and degrade this herbicide. We also used standard medium as control and get seventeen fungal strains. The seventeen fungal strains were identified as species of Botrytis, Fusarium, Aspergillus, Penicillium, Verticillium, Trichoderma and Paecilomyces. These results show the reduction in the number of fungal strains on solid medium containing glyphosate. Of the five isolated fungal species, Verticillium sp. strain KRP3 and Scopulariopsis sp. strain GRP2 were selected for further study based on their highest ratio of growth diameter. This study indicates that treatment of soil with glyphosate degrading fungus would be useful in some areas where this herbicide is extensively used.

  3. 75 FR 65012 - Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar

    Science.gov (United States)

    2010-10-21

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AD09-9-000] Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar October 13, 2010. The Federal Energy Regulatory Commission will host a Small/Low- Impact Hydropower Webinar on November 10, 2010, from...

  4. 76 FR 81929 - Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar

    Science.gov (United States)

    2011-12-29

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AD09-9-000] Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar The Federal Energy Regulatory Commission will host a Small/Low- Impact Hydropower Webinar on January 25, 2012, from 12:00 noon to 1:30 p.m...

  5. 76 FR 30937 - Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar

    Science.gov (United States)

    2011-05-27

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. AD09-9-000] Small Hydropower Development in the United States; Notice of Small/Low-Impact Hydropower Webinar The Federal Energy Regulatory Commission (FERC) will host a Small/ Low-Impact Hydropower Webinar on June 22, 2011, from 12 noon to 1 p.m...

  6. Improvements in the use of aquatic herbicides and establishment of future research directions

    Science.gov (United States)

    Getsinger, K.D.; Netherland, M.D.; Grue, C.E.; Koschnick, T.J.

    2008-01-01

    Peer-reviewed literature over the past 20 years identifies significant changes and improvements in chemical control strategies used to manage nuisance submersed vegetation. The invasive exotic plants hydrilla (Hydrilla verticillata L.f. Royle) and Eurasian watermilfoil (Myriophyllum spicatum L.) continue to spread and remain the plant species of greatest concern for aquatic resource managers at the national scale. Emerging exotic weeds of regional concern such as egeria (Egeria densa Planch.), curlyleaf pondweed (Potamogeton crispus L.), and hygrophila (Hygrophila polysperma (Roxb.) T. Anders), as well as native plants such as variable watermilfoil (Myriophyllum heterophyllum Michx), and cabomba (Cabomba caroliniana Gray) are invasive outside their home ranges. In addition, there is always the threat of new plant introductions such as African elodea (Lagarosiphon major (Ridley) Moss) or narrow-leaf anacharis (Egeria najas Planchon). The registration of the bleaching herbicide fluridone in the mid 1980s for whole-lake and large-scale management stimulated numerous lines of research involving reduction of use rates, plant selectivity, residue monitoring, and impacts on fisheries. In addition to numerous advances, the specificity of fluridone for a single plant enzyme led to the first documented case of herbicide resistance in aquatic plant management. The resistance of hydrilla to fluridone has stimulated a renewed interest by industry and others in the registration of alternative modes of action for aquatic use. These newer chemistries tend to be enzyme-specific compounds with favorable non-target toxicity profiles. Registration efforts have been facilitated by increased cooperation between key federal government agencies that have aquatic weed control and research responsibilities, and regulators within the U.S. Environmental Protection Agency (USEPA). We reviewed past and current research efforts to identify areas in need of further investigation and to establish

  7. Effects of herbicides on Behr's metalmark butterfly, a surrogate species for the endangered butterfly, Lange's metalmark

    International Nuclear Information System (INIS)

    Stark, John D.; Chen Xuedong; Johnson, Catherine S.

    2012-01-01

    Lange's metalmark butterfly, Apodemia mormo langei Comstock, is in danger of extinction due to loss of habitat caused by invasive exotic plants which are eliminating its food, naked stem buckwheat. Herbicides are being used to remove invasive weeds from the dunes; however, little is known about the potential effects of herbicides on butterflies. To address this concern we evaluated potential toxic effects of three herbicides on Behr's metalmark, a close relative of Lange's metalmark. First instars were exposed to recommended field rates of triclopyr, sethoxydim, and imazapyr. Life history parameters were recorded after exposure. These herbicides reduced the number of adults that emerged from pupation (24–36%). Each herbicide has a different mode of action. Therefore, we speculate that effects are due to inert ingredients or indirect effects on food plant quality. If these herbicides act the same in A. mormo langei, they may contribute to the decline of this species. - Highlights: ► We evaluated the effects of three herbicides on the butterfly, Behr's metalmark. ► These herbicides are used to control invasive weeds in butterfly habitat. ► The herbicides reduced adult butterfly emergence. - Herbicides are used to remove invasive weeds from butterfly habitat. Certain herbicides may be having a negative effect on butterflies.

  8. Analysis of the metabolic resistance of Ambrosia artemisiifolia L. to the herbicides action

    Directory of Open Access Journals (Sweden)

    Y.V. Lykholat

    2018-03-01

    Full Text Available Action and aftereffect of the herbicides with different modes of action on the common ragweed population were studied in the field and greenhouse experiments. Activation of glutathione S-transferase has been detected due to the action of herbicides Harness and Guardian-Tetra both in leaves of juvenile plants and in ragweed seeds, which indicates intensive detoxification of herbicides during weed ontogenesis. Electrophoretic analysis showed that four components in protein spectra of ragweed seeds were inherent in seeds collected from herbicides-treated plants only. Using the method of isoelectric focusing, three specific peroxidase isoforms associated with a certain mechanism of herbicidal action on the parent plants were found in leaves of the next generation plants. The results confirm the intensive adaptive changes in A. artemisiifolia population that could provide the metabolic resistance to different modes of the herbicide action. Keywords: Common ragweed, Metabolic resistance, Herbicide, Mode of action, Isoforms, Isoelectric

  9. Fourier transform of delayed fluorescence as an indicator of herbicide concentration.

    Science.gov (United States)

    Guo, Ya; Tan, Jinglu

    2014-12-21

    It is well known that delayed fluorescence (DF) from Photosystem II (PSII) of plant leaves can be potentially used to sense herbicide pollution and evaluate the effect of herbicides on plant leaves. The research of using DF as a measure of herbicides in the literature was mainly conducted in time domain and qualitative correlation was often obtained. Fourier transform is often used to analyze signals. Viewing DF signal in frequency domain through Fourier transform may allow separation of signal components and provide a quantitative method for sensing herbicides. However, there is a lack of an attempt to use Fourier transform of DF as an indicator of herbicide. In this work, the relationship between the Fourier transform of DF and herbicide concentration was theoretically modelled and analyzed, which immediately yielded a quantitative method to measure herbicide concentration in frequency domain. Experiments were performed to validate the developed method. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. How to test herbicides at forest tree nurseries.

    Science.gov (United States)

    Roger E. Sandquist; Peyton W. Owston; Stephen E. McDonald

    1981-01-01

    Procedures developed in a cooperative westwide study of weed control in forest tree nurseries are described in a form modified for use by nursery managers. The proven, properly designed test and evaluation methods can be used to generate data needed for evaluation and registration of herbicides.

  11. Epigenetic regulation – contribution to herbicide resistance in weeds?

    Czech Academy of Sciences Publication Activity Database

    Markus, C.; Pečinka, Aleš; Karan, R.; Barney, J. N.; Merotto, A.

    2018-01-01

    Roč. 74, č. 2 (2018), s. 275-281 ISSN 1526-498X Institutional support: RVO:61389030 Keywords : DNA methylation * epigenetic s * gene expression * gene regulation * herbicide detoxification * plant stress response Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 3.253, year: 2016

  12. Treating downy brome with herbicide and seeding with native shrubs

    Science.gov (United States)

    Suzanne Owen; Carolyn Sieg

    2011-01-01

    Downy brome or cheatgrass (Bromus tectorum L.) is one of the most invasive and widespread exotic plants in North America. Downy brome can reduce soil nutrient availability, alter native plant community composition, and increase fire frequencies. The effectiveness of Plateau® imazapic herbicide in reducing downy brome cover has been variable, and there is uncertainty...

  13. Are herbicide-resistant crops the answer to controlling Cuscuta?

    Science.gov (United States)

    Nadler-Hassar, Talia; Shaner, Dale L; Nissen, Scott; Westra, Phill; Rubin, Baruch

    2009-07-01

    Herbicide-resistant crop technology could provide new management strategies for the control of parasitic plants. Three herbicide-resistant oilseed rape (Brassica napus L.) genotypes were used to examine the response of attached Cuscuta campestris Yuncker to glyphosate, imazamox and glufosinate. Cuscata campestris was allowed to establish on all oilseed rape genotypes before herbicides were applied. Unattached seedlings of C. campestris, C. subinclusa Durand & Hilg. and C. gronovii Willd. were resistant to imazamox and glyphosate and sensitive to glufosinate, indicating that resistance initially discovered in C. campestris is universal to all Cuscuta species. Glufosinate applied to C. campestris attached to glufosinate-resistant oilseed rape had little impact on the parasite, while imazamox completely inhibited C. campestris growth on the imidazolinone-resistant host. The growth of C. campestris on glyphosate-resistant host was initially inhibited by glyphosate, but the parasite recovered and resumed growth within 3-4 weeks. The ability of C. campestris to recover was related to the quality of interaction between the host and parasite and to the resistance mechanism of the host. The parasite was less likely to recover when it had low compatibility with the host, indicating that parasite-resistant crops coupled with herbicide resistance could be highly effective in controlling Cuscuta. (c) 2009 by John Wiley & Sons, Ltd.

  14. Biological Efficacy of Herbicides for Weed Control in Noncropped Areas

    Directory of Open Access Journals (Sweden)

    Tsvetanka Dimitrova

    2009-01-01

    Full Text Available An increasing problem facing agricultural producers is the invasion of weeds, perennial in particular, so that implementation of industrial technologies is impossible without their highly efficient and rational control. For the purpose of studying efficient herbicides for weed control in noncropped areas (stubbles, a biological study of five total systemic herbicides was conducted in areas under natural weed infestation and pressure from othersurrounding weeds at the Institute of Forage Crops in Pleven in 2005-2007. The trials were carried out in field conditions using the block method with plot size of 20 m². Treatment was conducted at the predominant stage of budding of perennial dicotyledonous weeds and earing of monocotyledonous weeds. Herbicidal efficacy was recorded on the EWRS 9-score scale (0-100% killed weeds = score 9-1. It was found that treatment of noncropped areas (stubbles with the total systemic herbicides Touchdown System 4 (360 g/l glyphosate; Cosmic (360 g/l glyphosate; Roundup Plus (441 g/l glyphosate potassium salt; Leon 36 SL (360 g/l glyphosate and Glyphos Super 45 SL (450 g/l glyphosate was highly efficient, so that it was a successful element of a strategy for controlling weeds of different biological groups, and was especially effective against perennial weeds.

  15. Synthesis of a tritiated herbicide with high activity: methyl thifensulfuron

    International Nuclear Information System (INIS)

    Bastide, J.; Ortega, F.

    1993-01-01

    In order to study the binding on acetolactate synthase, a tritiated herbicide sulfonylurea (thifensulfuron methyl) of high specific activity was synthesized. By use of C 3 H 3 I for esterification of an acid group, a rapid incorporation of tritium into this compound may be achieved. (Author)

  16. Effect of atrazine (Herbicide) on blood parameters of common carp ...

    African Journals Online (AJOL)

    EJIRO

    could be used as an important tool for the assessment of pathological conditions of fish. ... agricultural or industrial areas have high probability of ... The use of herbicides to control aquatic weeds has ... Five hundred fish were stocked in a large cement tank (4 m × 6 m × 3 m) ..... Ecological risk assessment of atrazine in North.

  17. Ecological risks of pesticides in freshwater ecosystems; Part 1: herbicides

    NARCIS (Netherlands)

    Brock, T.C.M.; Lahr, J.; Brink, van den P.J.

    2000-01-01

    A literature review of freshwater model ecosystem studies with herbicides was performed to assess the NOEC[sub]ecosystem for individual compounds, to compare these threshold levels with water quality standards, and to evaluate the ecological consequences of exceeding these standards. Studies were

  18. Herbicide Trials on European Larch in Northern Wisconsin

    Science.gov (United States)

    Daniel A. Netzer

    1984-01-01

    Herbicides of 17 different rates and formulations were oversprayed on newly planted 1-0 European larch seedlings in teh spring of 1983 at the recommended rates. Simazine, bifenox, oxyfluorfen, promamide, and oryzalin provided adequate weed control with no damage to the larch. Height growth at the end of the first growing season was one-and-a-half times greater in the...

  19. Chromatographic determination of herbicide residues in various matrices

    Czech Academy of Sciences Publication Activity Database

    Cserháti, T.; Forgács, E.; Deyl, Zdeněk; Mikšík, Ivan; Eckhardt, Adam

    2004-01-01

    Roč. 18, č. 6 (2004), s. 350-359 ISSN 0269-3879 Institutional research plan: CEZ:AV0Z5011922 Keywords : herbicide residues * extraction methods * HPLC Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.069, year: 2004

  20. Vinegar as a broadcast herbicide for spring-transplanted onions

    Science.gov (United States)

    The weed control challenges for onion production are formidable; however, these challenges are even greater for those considering organic crop production. Organic onion producers need additional organic herbicides that can effectively provide post-emergent weed control. Field research was conducted...

  1. Herbicide-resistant weed management: focus on glyphosate.

    Science.gov (United States)

    Beckie, Hugh J

    2011-09-01

    This review focuses on proactive and reactive management of glyphosate-resistant (GR) weeds. Glyphosate resistance in weeds has evolved under recurrent glyphosate usage, with little or no diversity in weed management practices. The main herbicide strategy for proactively or reactively managing GR weeds is to supplement glyphosate with herbicides of alternative modes of action and with soil-residual activity. These herbicides can be applied in sequences or mixtures. Proactive or reactive GR weed management can be aided by crop cultivars with alternative single or stacked herbicide-resistance traits, which will become increasingly available to growers in the future. Many growers with GR weeds continue to use glyphosate because of its economical broad-spectrum weed control. Government farm policies, pesticide regulatory policies and industry actions should encourage growers to adopt a more proactive approach to GR weed management by providing the best information and training on management practices, information on the benefits of proactive management and voluntary incentives, as appropriate. Results from recent surveys in the United States indicate that such a change in grower attitudes may be occurring because of enhanced awareness of the benefits of proactive management and the relative cost of the reactive management of GR weeds. Copyright © 2011 Society of Chemical Industry.

  2. Hazard and risk of herbicides for marine microalgae

    NARCIS (Netherlands)

    Sjollema, S.B.; Martínez-García, G.; van der Geest, H.G.; Kraak, M.H.S.; Booij, P.; Vethaak, A.D.; Admiraal, W.

    2014-01-01

    Due to their specific effect on photosynthesis, herbicides pose a potential threat to coastal and estuarine microalgae. However, comprehensive understanding of the hazard and risk of these contaminants is currently lacking. Therefore the aim of the present study was to investigate the toxic effects

  3. Cytogenetic studies of three triazine herbicides. I. In vitro studies

    Science.gov (United States)

    Atrazine, simazine, and cyanazine are widely used pre-emergence and post-emergence triazine herbicides that have made their way into the potable water supply of many agricultural communities. Because of this and the prevalence of contradictory cytogenetic studies in the literatur...

  4. Hyperammonemia following glufosinate-containing herbicide poisoning: a potential marker of severe neurotoxicity.

    Science.gov (United States)

    Mao, Yan-Chiao; Wang, Jiaan-Der; Hung, Dong-Zong; Deng, Jou-Fang; Yang, Chen-Chang

    2011-01-01

    Glufosinate-ammonium (GLA) is the active ingredient of certain widely used non-selective contact herbicides ("e.g.," Basta). Although it is thought to be much less toxic to humans than to plants, deliberate ingestion of GLA could still lead to serious effects ("e.g.," neurotoxicity) or even death. Three cases presented with delayed-onset neurotoxicity including stupor, delirium, seizures, coma, and amnesia after ingesting large amount of Basta. Considering that GLA could irreversibly inhibit glutamine synthetase (GS) in plants, we performed serial measurements of serum ammonia in those patients and revealed marked hyperammonemia in all of them. All patients recovered with the sequelae of persistent amnesia after receiving intensive care and hemodialysis. We speculated that the occurrence of hyperammonemia might at least be partially related to GS inhibition in humans. Moreover, hyperammonemia could serve as a potential marker of severe neurotoxicity, especially prolonged amnesia, following massive ingestion of GLA-containing herbicides. The possible dose-response relation between GLA exposure and serum ammonia level, however, needs more investigations.

  5. Will the Amaranthus tuberculatus Resistance Mechanism to PPO-Inhibiting Herbicides Evolve in Other Amaranthus Species?

    Directory of Open Access Journals (Sweden)

    Chance W. Riggins

    2012-01-01

    Full Text Available Resistance to herbicides that inhibit protoporphyrinogen oxidase (PPO has been slow to evolve and, to date, is confirmed for only four weed species. Two of these species are members of the genus Amaranthus L. Previous research has demonstrated that PPO-inhibitor resistance in A. tuberculatus (Moq. Sauer, the first weed to have evolved this type of resistance, involves a unique codon deletion in the PPX2 gene. Our hypothesis is that A. tuberculatus may have been predisposed to evolving this resistance mechanism due to the presence of a repetitive motif at the mutation site and that lack of this motif in other amaranth species is why PPO-inhibitor resistance has not become more common despite strong herbicide selection pressure. Here we investigate inter- and intraspecific variability of the PPX2 gene—specifically exon 9, which includes the mutation site—in ten amaranth species via sequencing and a PCR-RFLP assay. Few polymorphisms were observed in this region of the gene, and intraspecific variation was observed only in A. quitensis. However, sequencing revealed two distinct repeat patterns encompassing the mutation site. Most notably, A. palmeri S. Watson possesses the same repetitive motif found in A. tuberculatus. We thus predict that A. palmeri will evolve resistance to PPO inhibitors via the same PPX2 codon deletion that evolved in A. tuberculatus.

  6. A microcosm system to evaluate the toxicity of the triazine herbicide simazine on aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Vervliet-Scheebaum, Marco, E-mail: marco.vervliet@biologie.uni-freiburg.d [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Straus, Alain [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Tremp, Horst [Institute for Environmental Sciences, University Koblenz-Landau, Fortstr. 7, 76829 Landau (Germany); Hamer, Mick [Ecological Sciences, Syngenta Crop Protection AG, Jealott' s Hill International Research Centre, Bracknell, Berkshire RG42 6EY (United Kingdom); Maund, Stephen J. [Ecological Sciences, Syngenta Crop Protection AG, 4002 Basel (Switzerland); Wagner, Edgar [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg (Germany); Schulz, Ralf [Institute for Environmental Sciences, University Koblenz-Landau, Fortstr. 7, 76829 Landau (Germany)

    2010-02-15

    This study evaluates the effects of the triazine herbicide simazine in an outdoor pond microcosm test system that contained two submerged rooted species (Myriophyllum spicatum and Elodea canadensis) and two emergent rooted species (Persicaria amphibia and Glyceria maxima) over a period of 84 days. Simazine was applied to the microcosms at nominal concentrations of 0.05, 0.5 and 5 mg/L. General biological endpoints and physiological endpoints were used to evaluate herbicide toxicity on macrophytes and the algae developing naturally in the system. Concentration-related responses of macrophytes and algae were obtained for the endpoints selected, resulting in a no observed ecologically adverse effect concentration (NOEAEC) at simazine concentrations of 0.05 mg active ingredient/L after 84 days. E. canadensis was the most negatively affected species based on length increase, which was consistently a very sensitive parameter for all macrophytes. The experimental design presented might constitute a suitable alternative to conventional laboratory single-species testing. - Simazine at concentrations of 0.05 mg/L does not cause long-term negative effects to aquatic macrophytes or algae.

  7. Winter Annual Weed Response to Nitrogen Sources and Application Timings prior to a Burndown Corn Herbicide

    Directory of Open Access Journals (Sweden)

    Kelly A. Nelson

    2015-01-01

    Full Text Available Autumn and early preplant N applications, sources, and placement may affect winter annual weed growth. Field research evaluated (1 the effect of different nitrogen sources in autumn and early preplant on total winter annual weed growth (2006–2010, and (2 strip-till and broadcast no-till N applied in autumn and early preplant on henbit (Lamium amplexicaule L. growth (2008–2010 prior to a burndown herbicide application. Total winter annual weed biomass was greater than the nontreated control when applying certain N sources in autumn or early preplant for no-till corn. Anhydrous ammonia had the lowest average weed density (95 weeds m−2, though results were inconsistent over the years. Winter annual weed biomass was lowest (43 g m−2 when applying 32% urea ammonium nitrate in autumn and was similar to applying anhydrous ammonia in autumn or early preplant and the nontreated control. Henbit biomass was 28% greater when applying N in the autumn compared to an early preplant application timing. Nitrogen placement along with associated tillage with strip-till placement was important in reducing henbit biomass. Nitrogen source selection, application timing, and placement affected the impact of N on winter annual weed growth and should be considered when recommending a burndown herbicide application timing.

  8. A microcosm system to evaluate the toxicity of the triazine herbicide simazine on aquatic macrophytes

    International Nuclear Information System (INIS)

    Vervliet-Scheebaum, Marco; Straus, Alain; Tremp, Horst; Hamer, Mick; Maund, Stephen J.; Wagner, Edgar; Schulz, Ralf

    2010-01-01

    This study evaluates the effects of the triazine herbicide simazine in an outdoor pond microcosm test system that contained two submerged rooted species (Myriophyllum spicatum and Elodea canadensis) and two emergent rooted species (Persicaria amphibia and Glyceria maxima) over a period of 84 days. Simazine was applied to the microcosms at nominal concentrations of 0.05, 0.5 and 5 mg/L. General biological endpoints and physiological endpoints were used to evaluate herbicide toxicity on macrophytes and the algae developing naturally in the system. Concentration-related responses of macrophytes and algae were obtained for the endpoints selected, resulting in a no observed ecologically adverse effect concentration (NOEAEC) at simazine concentrations of 0.05 mg active ingredient/L after 84 days. E. canadensis was the most negatively affected species based on length increase, which was consistently a very sensitive parameter for all macrophytes. The experimental design presented might constitute a suitable alternative to conventional laboratory single-species testing. - Simazine at concentrations of 0.05 mg/L does not cause long-term negative effects to aquatic macrophytes or algae.

  9. Urinary Concentrations of Insecticide and Herbicide Metabolites among Pregnant Women in Rural Ghana: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Blair J. Wylie

    2017-03-01

    Full Text Available Use of pesticides by households in rural Ghana is common for residential pest control, agricultural use, and for the reduction of vectors carrying disease. However, few data are available about exposure to pesticides among this population. Our objective was to quantify urinary concentrations of metabolites of organophosphate (OP, pyrethroid, and select herbicides during pregnancy, and to explore exposure determinants. In 2014, 17 pregnant women from rural Ghana were surveyed about household pesticide use and provided weekly first morning urine voids during three visits (n = 51 samples. A total of 90.1% (46/51 of samples had detectable OP metabolites [geometric mean, GM (95% CI: 3,5,6-trichloro-2-pyridinol 0.54 µg/L (0.36–0.81, para-nitrophenol 0.71 µg/L (0.51–1.00], 75.5% (37/49 had detectable pyrethroid metabolites [GM: 3-phenoxybenzoic acid 0.23 µg/L (0.17, 0.32], and 70.5% (36/51 had detectable 2,4-dichlorophenoxyacetic acid levels, a herbicide [GM: 0.46 µg/L (0.29–0.73]. Concentrations of para-nitrophenol and 2,4-dichlorophenoxyacetic acid in Ghanaian pregnant women appear higher when compared to nonpregnant reproductive-aged women in a reference U.S. population. Larger studies are necessary to more fully explore predictors of exposure in this population.

  10. Adsorption of triazine herbicides from aqueous solution by functionalized multiwall carbon nanotubes grown on silicon substrate

    Science.gov (United States)

    D'Archivio, Angelo Antonio; Maggi, Maria Anna; Odoardi, Antonella; Santucci, Sandro; Passacantando, Maurizio

    2018-02-01

    Multi-walled carbon nanotubes (MWCNTs), because of their small size and large available surface area, are potentially efficient sorbents for the extraction of water solutes. Dispersion of MWCNTs in aqueous medium is suitable to adsorb organic contaminants from small sample volumes, but, the recovery of the suspended sorbent for successive re-use represents a critical step, which makes this method inapplicable in large-scale water-treatment technologies. To overcome this problem, we proposed here MWCNTs grown on silicon supports and investigated on a small-volume scale their adsorption properties towards triazine herbicides dissolved in water. The adsorption efficiency of the supported MWCNTs has been tested on seven triazine herbicides, which are emerging water contaminants in Europe and USA, because of their massive use, persistence in soils and potential risks for the aquatic organisms and human health. The investigated compounds, in spite of their common molecular skeleton, cover a relatively large property range in terms of both solubility in water and hydrophilicity/hydrophobicity. The functionalisation of MWCNTs carried out by acidic oxidation, apart from increasing wettability of the material, results in a better adsorption performance. Increasing of functionalisation time between 17 and 60 h progressively increases the extraction of all seven pesticides and produces a moderate increment of selectivity.

  11. Antifungal and Herbicidal Effects of Fruit Essential Oils of Four Myrtus communis Genotypes.

    Science.gov (United States)

    Kordali, Saban; Usanmaz, Ayse; Cakir, Ahmet; Komaki, Amanmohammad; Ercisli, Sezai

    2016-01-01

    The chemical composition of the essential oils isolated by hydrodistillation from the fruits of four selected Myrtus communis L. genotypes from Turkey was characterized by GC-FID and GC/MS analyses. 1,8-Cineole (29.20-31.40%), linalool (15.67-19.13%), α-terpineol (8.40-18.43%), α-pinene (6.04-20.71%), and geranyl acetate (3.98-7.54%) were found to be the major constituents of the fruit essential oils of all M. communis genotypes investigated. The oils were characterized by high amounts of oxygenated monoterpenes, representing 73.02-83.83% of the total oil compositions. The results of the fungal growth inhibition assays showed that the oils inhibited the growth of 19 phytopathogenic fungi. However, their antifungal activity was generally lower than that of the commercial pesticide benomyl. The herbicidal effects of the oils on the seed germination and seedling growth of Amaranthus retroflexus L., Chenopodium album L., Cirsium arvense (L.) Scop., Lactuca serriola L., and Rumex crispus L. were also determined. The oils completely or partly inhibited the seed germinations and seedling growths of the plants. The findings of the present study suggest that the M. communis essential oils might have potential to be used as natural herbicides as well as fungicides. Copyright © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

  12. An innovative bovine odorant binding protein-based filtering cartridge for the removal of triazine herbicides from water.

    Science.gov (United States)

    Bianchi, Federica; Basini, Giuseppina; Grolli, Stefano; Conti, Virna; Bianchi, Francesco; Grasselli, Francesca; Careri, Maria; Ramoni, Roberto

    2013-01-01

    Odorant binding protein (OBP) is a multi-functional scavenger for small hydrophobic molecules dissolved in the mucus lining the nasal epithelia of mammals, characterized by broad ligand binding specificity towards a large number of structurally unrelated natural and synthetic molecules of different chemical classes. Here, we demonstrate for the first time the application of OBP as the active element of an innovative filtering matrix for the removal of environmental pollutants such as triazine herbicides from water samples. The filtering device, obtained by coupling histidine-tagged bovine OBP to a nickel nitrilotriacetic acid (Ni-NTA) agarose resin, was characterized in terms of retention capacity for the herbicides atrazine, simazine, and propazine. Analysis of these herbicides at trace levels with solid-phase microextraction followed by gas chromatography-mass spectrometry using the selected ion monitoring mode proved the capabilities of the proposed device for the decontamination of surface and groundwater samples in the 0.2-2,300 μg/L concentration range, obtaining a reduction in the triazine content greater than 97 %, thus suggesting its possible use for the potabilization of water.

  13. Evaluating grass strips trapping efficiency of sediments and herbicides

    Science.gov (United States)

    Burguet, Maria; Guzmán, Gema; de Luna, Elena; Taguas, Encarnación V.; Gómez, José Alfonso

    2016-04-01

    Water erosion and associated offsite contamination are major environmental risks in many Mediterranean crops such as olives or vineyards (Beaufoy, 2001; Gómez et al., 2011). The use of cover crops has been prescribed as a mitigation measure for both problems because permanent cover crops have demonstrated to reduce sediment and agrochemical loads (e.g. Gómez, 2009a, b). However, large uncertainty remains about its effectiveness degree to reduce sediment and agrochemical contribution to streams due to the limited number of available studies, and the large variability observed under field conditions (Taguas et al., 2012). Furthermore, the determination of sediment and herbicide sources using suitable sediment tracing/fingerprinting properties has been noted as one tool to evaluate the effectiveness and functioning of vegetated filters at the catchment scale (Koiter et al., 2013). The objectives of the present study were twofold: [1] to explore the combined use of natural and simulated rainfall and magnetic iron oxide in understanding the performance of vegetation strips on runoff and soil and herbicide losses at plot scale and, [2] to evaluate the effectiveness degree of vegetation strips in buffering sediment and herbicide from bare soil areas under different conditions compared to a control situation with no strips. This study encompasses six rainfall simulations under four different soil managements combining the use of a magnetic iron oxide as a sediment tracer to obtain a better understanding of the vegetation strips trapping efficiency. Three runoff plots of 6 m × 14 m were established in a 20% hillslope under a Fluvisol alluvial terrace. Each of the plots contained three bare strips tagged with magnetic iron oxide and three strips with Lolium multiflorum L. The soil management simulated scenarios were: immediately after sowing the vegetation cover (June 2011cover crop), with settled vegetation cover (June 2012cover crop), after 5 cm of deep ploughing

  14. Symbolic Meanings of High and Low Impact Daily Consumption Practices in Different Cultures

    DEFF Research Database (Denmark)

    Ger, Güliz; Wilhite, Harold; Halkier, Bente

    1998-01-01

    . They influence our choices and practices whether it is by motivating or impeding them. In this study we will look at the symbolic meanings of high and low environmental impact consumption practices. In order to create desirable social markers for environmentally-friendly practices and/or to change high impact...... practices, we need to understand emergent practices and their existing cultural meanings. Thus we have chosen three fields of daily consumption practices - food consumption, transport and hygiene - and sorted out the relatively environmentally friendly (low impact) and the relatively environmentally...

  15. Analysis and detection of the herbicides dimethenamid and flufenacet and their sulfonic and oxanilic acid degradates in natural water

    Science.gov (United States)

    Zimmerman, L.R.; Schneider, R.J.; Thurman, E.M.

    2002-01-01

    Dimethenamid [2-chloro-N-(2,4-dimethyl-3-thienyl)-N-(2-methoxy-1-methylethyl)acetamide] and flufenacet [N-(4-fluorophenyl)-N-(1-methylethyl)-2-(5-(trifluoromethyl)-1,3,4- thiadiazol-2-yl)oxy] were isolated by C-18 solid-phase extraction and separated from their ethanesulfonic acid (ESA) and oxanilic acid (OXA) degradates during their elution using ethyl acetate for the parent compound, followed by methanol for the polar degradates. The parent compounds were detected using gas chromatography-mass spectrometry in selected-ion mode. The ESA and OXA degradates were detected using high-performance liquid chromatography-electrospray mass spectrometry (HPLC-ESPMS) in negative-ion mode. The method detection limits for a 123-mL sample ranged from 0.01 to 0.07 μg/L. These methods are compatible with existing methods and thus allow for analysis of 17 commonly used herbicides and 18 of their degradation compounds with one extraction. In a study of herbicide transport near the mouth of the Mississippi River during 1999 and 2000, dimethenamid and its ESA and OXA degradates were detected in surface water samples during the annual spring flushes. For flufenacet, the only detections at the study site were for the ESA degradates in samples collected at the peak of the herbicide spring flush in 2000. The low frequency of detections in surface water likely is due to dimethenamid and flufenacet being relatively new herbicides. In addition, detectable amounts of the stable degradates have not been detected in ground water.

  16. Influence of herbicide structure, clay acidity, and humic acid coating on acetanilide herbicide adsorption on homoionic clays.

    Science.gov (United States)

    Liu, Weiping; Gan, Jianying; Yates, Scott R

    2002-07-03

    Adsorption of chloroacetanilide herbicides on homoionic montmorillonite was studied by coupling batch equilibration and FT-IR analysis. Adsorption decreased in the order metolachlor > acetochlor > alachlor > propachlor on Ca(2+)- or Mg(2+)-saturated clays and in the order metolachlor > alachlor > acetachlor > propachlor on Al(3+)- or Fe(3+)-saturated clays. FT-IR spectra showed that the carbonyl group of the herbicide molecule was involved in bonding. For the same herbicide, adsorption of alachlor, acetachlor, and metolachlor on clay followed the order Ca(2+) approximately Mg(2+) < Al(3+) < or = Fe(3+), which coincided with the increasing acidity of homoionic clays. Adsorption of propachlor, however, showed an opposite dependence, suggesting a different governing interaction. In clay and humic acid mixtures, herbicide adsorption was less than that expected from independent additive adsorption by the individual constituents, and the deviation was dependent on the clay-to-humic acid ratio, with the greatest deviation consistently occurring at a 60:40 clay-to-humic acid ratio.

  17. From Rain Tanks to Catchments: Use of Low-Impact Development To Address Hydrologic Symptoms of the Urban Stream Syndrome.

    Science.gov (United States)

    Askarizadeh, Asal; Rippy, Megan A; Fletcher, Tim D; Feldman, David L; Peng, Jian; Bowler, Peter; Mehring, Andrew S; Winfrey, Brandon K; Vrugt, Jasper A; AghaKouchak, Amir; Jiang, Sunny C; Sanders, Brett F; Levin, Lisa A; Taylor, Scott; Grant, Stanley B

    2015-10-06

    Catchment urbanization perturbs the water and sediment budgets of streams, degrades stream health and function, and causes a constellation of flow, water quality, and ecological symptoms collectively known as the urban stream syndrome. Low-impact development (LID) technologies address the hydrologic symptoms of the urban stream syndrome by mimicking natural flow paths and restoring a natural water balance. Over annual time scales, the volumes of stormwater that should be infiltrated and harvested can be estimated from a catchment-scale water-balance given local climate conditions and preurban land cover. For all but the wettest regions of the world, a much larger volume of stormwater runoff should be harvested than infiltrated to maintain stream hydrology in a preurban state. Efforts to prevent or reverse hydrologic symptoms associated with the urban stream syndrome will therefore require: (1) selecting the right mix of LID technologies that provide regionally tailored ratios of stormwater harvesting and infiltration; (2) integrating these LID technologies into next-generation drainage systems; (3) maximizing potential cobenefits including water supply augmentation, flood protection, improved water quality, and urban amenities; and (4) long-term hydrologic monitoring to evaluate the efficacy of LID interventions.

  18. Seletivicty of eucalyptus genotypes to herbicides rates / Seletividade de genótipos de eucalipto a doses de herbicidas

    Directory of Open Access Journals (Sweden)

    Siumar Pedro Tironi

    2010-09-01

    Full Text Available The aim of this work was to quantify the herbicide selectivity applied at post-emergence of eucalyptus in different rates. The experiment was conducted in greenhouse conditions in the period from January to March 2007 at the Faculdade de Agronomia Eliseu Maciel in Universidade Federal de Pelotas – Capão do Leão-RS. Experimental design was completely randomized, with four replications. Treatments were in a factorial scheme: factor A - eucalyptus genotypes (E. globulus e E. saligna, factor B - herbicides (isoxaflutole, oxyfluorfen, bispyribac-sodium and sethoxydim+diclosulam, and factor C – rates of the registered average for weed control (0, 50, 100, 150 e 200%. Phytotoxicity, height, stem diameter and dry matter were evaluated. E. globulus genotype was more sensitive to herbicides than E. saligna. The mixture of the herbicides sethoxydim plus diclosulam showed potential to be used in eucalyptus. Bispyribac-sodium herbicide was the most toxic and isoxaflutole was the most selective to the studied genotypes.O objetivo deste trabalho foi quantificar a seletividade de herbicidas aplicados em pós-emergência na cultura do eucalipto em função de diferentes doses. O experimento foi realizado em casa de vegetação, pertencente a Faculdade de Agronomia Eliseu Maciel da Universidade Federal de Pelotas, no Município de Capão do Leão – RS, no período de janeiro a março de 2007. O delineamento experimental utilizado foi completamente casualizado, com quatro repetições. Os tratamentos foram arranjados em esquema fatorial, onde o fator A testou genótipos de eucalipto (E. globulus e E. saligna, o fator B comparou quatro herbicidas (isoxaflutole, oxyfluorfen, bispyribac-sodium e sethoxydim+diclosulam e o fator C doses (0, 50, 100, 150 e 200% da dose média registrada para controle de plantas daninhas. As variáveis avaliadas foram fitotoxicidade, estatura, diâmetro do caule e matéria seca da parte aérea das plantas de eucalipto. O gen

  19. Wind and wildlife in the Northern Great Plains: identifying low-impact areas for wind development.

    Directory of Open Access Journals (Sweden)

    Joseph Fargione

    Full Text Available Wind energy offers the potential to reduce carbon emissions while increasing energy independence and bolstering economic development. However, wind energy has a larger land footprint per Gigawatt (GW than most other forms of energy production and has known and predicted adverse effects on wildlife. The Northern Great Plains (NGP is home both to some of the world's best wind resources and to remaining temperate grasslands, the most converted and least protected ecological system on the planet. Thus, appropriate siting and mitigation of wind development is particularly important in this region. Steering energy development to disturbed lands with low wildlife value rather than placing new developments within large and intact habitats would reduce impacts to wildlife. Goals for wind energy development in the NGP are roughly 30 GW of nameplate capacity by 2030. Our analyses demonstrate that there are large areas where wind development would likely have few additional impacts on wildlife. We estimate there are ∼1,056 GW of potential wind energy available across the NGP on areas likely to have low-impact for biodiversity, over 35 times development goals. New policies and approaches will be required to guide wind energy development to low-impact areas.

  20. A comparison of the herbicide tolerances of rare and common plants in an agricultural landscape.

    Science.gov (United States)

    Egan, J Franklin; Graham, Ian M; Mortensen, David A

    2014-03-01

    Declining plant biodiversity in agroecosystems has often been attributed to escalating use of chemical herbicides, but other changes in farming systems, including the clearing of seminatural habitat fragments, confound the influence of herbicides. The present study introduces a new approach to evaluate the impacts of herbicide pollution on plant communities at landscape or regional scales. If herbicides are in fact a key factor shaping agricultural plant diversity, one would expect to see the signal of past herbicide impacts in the current plant community composition of an intensively farmed region, with common, successful species more tolerant to widely used herbicides than rare or declining species. Data from an extensive field survey of plant diversity in Lancaster County, Pennsylvania, USA, were compared with herbicide bioassay experiments in a greenhouse to test the hypothesis that common species possess higher herbicide tolerances than rare species. Five congeneric pairs of rare and common species were treated with 3 commonly used herbicide modes of action in bioassay experiments, and few significant differences were found in the tolerances of rare species relative to common species. These preliminary results suggest that other factors beyond herbicide exposure may be more important in shaping the distribution and abundance of plant species diversity across an agricultural landscape. © 2014 SETAC.

  1. Monitoring of phenylurea and propanil herbicides in river water by solid-phase-extraction high performance liquid chromatography with photoinduced-fluorimetric detection.

    Science.gov (United States)

    de la Peña, A Muñoz; Mahedero, M C; Bautista-Sánchez, A

    2003-06-13

    The separation and determination of five herbicides, including propanil and the phenylureas diuron, isoproturon, linuron and neburon, has been performed by an HPLC method, using photochemically-induced fluorescence detection. The non-fluorescent herbicides were transformed into fluorescent compounds by post-column photochemical reaction. A 60:40 (v/v) acetonitrile-buffer solution of potassium phosphate dibasic (pH 7, 0.01 M) was used for the chromatographic elution to separate propanil, linuron and neburon. The overlapping of isoproturon and diuron peaks, in the selected conditions, was resolved by changing the initial movil phase composition to 50:50 (v/v) methanol-buffer solution of potassium phosphate dibasic (pH 7, 0.01 M). The procedure was applied with satisfactory results to the analysis of these herbicides in Guadiana river water samples (Badajoz, Spain), allowing the detection of herbicide residues in the order of mug l(-1), by using a solid-phase extraction (SPE) pre-concentration step.

  2. Transformation of the herbicide [14C]glufosinate in soils

    International Nuclear Information System (INIS)

    Smith, A.E.

    1989-01-01

    The degradation of 2 μg/g [ 14 C]glufosinate (DL-homoalan-4-ylmethylphosphinic acid) was studied in clay, clay loam, and sandy loam soils at 85% field capacity and at 20 degree C. Over a 4-week period the soils were extracted and analyzed for transformation products by radiochemical and gas chromatographic techniques. In all soils there was release of [ 14 C]carbon dioxide and formation of [ 14 C]-3-(hydroxymethylphosphinyl)propionic acid (MPPA) as major degradation products. Within 21 days, about 55% of the applied 14 C herbicide had been transformed to MPPA in the sandy loam and 19% to [ 14 C]carbon dioxide. After 28 days, approximately 45% of the 14 C herbicide had been transformed to MPPA in the clay and clay loam and 10% released as [ 14 C]carbon dioxide. At all samplings, other 14 C transformation products appeared to be insignificant

  3. Herbicide contamination in carrot grown in punjab, pakistan

    International Nuclear Information System (INIS)

    Amjad, M.; Ahmad, T.; Jahangir, M.M.

    2013-01-01

    Food safety and security is a burning issue of the time whereas vegetable production is an important aspect of agriculture. Use of herbicides for vegetable production is very common in Pakistan but no proper procedure has been planned to keep optimal level of doses of herbicide under permissible limit. To estimate the pesticide residues, samples from the leading carrot producing sites were collected along with the samples from the market. The samples were processed using standard procedures and qualitative and quantitative analysis was performed by Gas Chromatography-Mass Spectrometry (GC-MS). It was concluded that all the samples were contaminated with S-metolachlor in the range of 0.45 to 0.73 mg kg-1 which was above the permissible limit (0.40 mg kg-1). (author)

  4. Herbicide spring treatments for the control of brome grasses (Bromus spp. in winter cereals

    Directory of Open Access Journals (Sweden)

    Gehring, Klaus

    2014-02-01

    Full Text Available The efficacy of different ALS-inhibiting herbicides for the control of brome species (Bromus spp. was tested in three field trials in the year 2010 – 2012 in the region of North-West-Bavaria Franken. As a result of the trials the standard herbicide Attribut (Propoxycarbazone was confirmed for the control of brome. In case of infestation with brome and black grass the herbicide Broadway (Pyroxsulam offers a certain control of both problematic grass weeds. This illustrates the high dependency of sufficient brome control in winter cereals on the effectiveness of specific ALS-Inhibitor herbicides. Because of the high risk of herbicide resistance to ACCaseand ALS-inhibiting herbicides in brome, integrated weed management is essential for the sustainable control of brome in winter cereals, respectively winter wheat.

  5. Glyphosate herbicide affects belowground interactions between earthworms and symbiotic mycorrhizal fungi in a model ecosystem

    Science.gov (United States)

    Zaller, Johann G.; Heigl, Florian; Ruess, Liliane; Grabmaier, Andrea

    2014-01-01

    Herbicides containing glyphosate are widely used in agriculture and private gardens, however, surprisingly little is known on potential side effects on non-target soil organisms. In a greenhouse experiment with white clover we investigated, to what extent a globally-used glyphosate herbicide affects interactions between essential soil organisms such as earthworms and arbuscular mycorrhizal fungi (AMF). We found that herbicides significantly decreased root mycorrhization, soil AMF spore biomass, vesicles and propagules. Herbicide application and earthworms increased soil hyphal biomass and tended to reduce soil water infiltration after a simulated heavy rainfall. Herbicide application in interaction with AMF led to slightly heavier but less active earthworms. Leaching of glyphosate after a simulated rainfall was substantial and altered by earthworms and AMF. These sizeable changes provide impetus for more general attention to side-effects of glyphosate-based herbicides on key soil organisms and their associated ecosystem services. PMID:25005713

  6. Weed emergence on long years’ not herbicide treated fields - duration of the after-effects

    Directory of Open Access Journals (Sweden)

    Schwarz, Jürgen

    2016-02-01

    Full Text Available In a long-term field trial plots were not treated with herbicides for 12 years (from 1996 to 2007. Two different crop rotations with 50% or 66% of cereals in the rotation were tested. At the same time in each crop rotation two different plant protection strategies were established. Since autumn 2007 the former controls not sprayed with any herbicide have been treated with herbicides. The crop rotation was unified. In that long-term field trial plots always treated with herbicides exist also. Weeds were counted by number and species before herbicide treatments. The comparison of these two different plots (treated and untreated shows what after-effect exists on the formerly untreated plots even after eight years. The emergence of weeds is still higher. Also the different crop rotations are still perceptible. For the plant protection strategy with the lower herbicide amounts the differences blur now.

  7. Three-parameter modeling of the soil sorption of acetanilide and triazine herbicide derivatives.

    Science.gov (United States)

    Freitas, Mirlaine R; Matias, Stella V B G; Macedo, Renato L G; Freitas, Matheus P; Venturin, Nelson

    2014-02-01

    Herbicides have widely variable toxicity and many of them are persistent soil contaminants. Acetanilide and triazine family of herbicides have widespread use, but increasing interest for the development of new herbicides has been rising to increase their effectiveness and to diminish environmental hazard. The environmental risk of new herbicides can be accessed by estimating their soil sorption (logKoc), which is usually correlated to the octanol/water partition coefficient (logKow). However, earlier findings have shown that this correlation is not valid for some acetanilide and triazine herbicides. Thus, easily accessible quantitative structure-property relationship models are required to predict logKoc of analogues of the these compounds. Octanol/water partition coefficient, molecular weight and volume were calculated and then regressed against logKoc for two series of acetanilide and triazine herbicides using multiple linear regression, resulting in predictive and validated models.

  8. Herbicide contamination and the potential impact to seagrass meadows in Hervey Bay, Queensland, Australia.

    Science.gov (United States)

    McMahon, Kathryn; Bengtson Nash, Susan; Eaglesham, Geoff; Müller, Jochen F; Duke, Norman C; Winderlich, Steve

    2005-01-01

    Low concentrations of herbicides (up to 70 ng l(-1)), chiefly diuron (up to 50 ng l(-1)) were detected in surface waters associated with inter-tidal seagrass meadows of Zostera muelleri in Hervey Bay, south-east Queensland, Australia. Diuron and atrazine (up to 1.1 ng g(-1) dry weight of sediment) were detected in the sediments of these seagrass meadows. Concentration of the herbicides diuron, simazine and atrazine increased in surface waters associated with seagrass meadows during moderate river flow events indicating herbicides were washed from the catchment to the marine environment. Maximum herbicide concentration (sum of eight herbicides) in the Mary River during a moderate river flow event was 4260 ng l(-1). No photosynthetic stress was detected in seagrass in this study during low river flow. However, with moderate river flow events, nearshore seagrasses are at risk of being exposed to concentrations of herbicides that are known to inhibit photosynthesis.

  9. Herbicidal Activity of Coumarin When Applied as a Pre-plant Incorporated into Soil

    Directory of Open Access Journals (Sweden)

    Amir-Hossein NAZEMI

    2015-06-01

    Full Text Available Due to having a short half-life and novel site of action, the herbicidal potential of natural compounds are lionized. Coumarin is a secondary metabolite from Lavandula sp., family Lamiacae. The impact of eight concentrations of coumarin (0, 100, 200, 400, 800, 1600, 3200 and 6400 ppm were separately used as a pre-plant incorporated into soil on six plant species under greenhouse conditions. Generally, coumarin had phytotoxic effect against all plant species. The phytotoxic effect was concentration-dependent. The high concentrations could inhibit the emergence of seedlings (probably by stopping germination of seeds. Based on ED50 parameter, the ranking of plant species for tolerance to coumarin was S. halepense > Z. mays > C. album > A. retroflexus > E. cruss-gali > P. oleracea. Based on selectivity index, coumarin at a concentration of 365.69 ppm can control P. oleracea without damaging Z. mays, whereas any concentration it cannot control other weeds without damaging Z. mays.

  10. Comparison of different physiological parameter responses in Lemna minor and Scenedesmus obliquus exposed to herbicide flumioxazin

    Energy Technology Data Exchange (ETDEWEB)

    Geoffroy, Laure; Frankart, Cecile; Eullaffroy, Philippe

    2004-09-01

    The sensitivity of different physiological parameters in Scenedesmus obliquus and Lemna minor exposed to herbicide (flumioxazin) was investigated to indicate the most convenient and sensitive parameter. To assess toxicity of flumioxazin, we used a panel of biomarkers: pigment contents, chlorophyll fluorescence parameters and antioxidative enzyme activities. Algae and duckweed were exposed to 48-h IC{sub 50} for growth rate. In L. minor, the sensitivity of the parameters was as follows: Q{sub N}>Oxygen emission>PHIs{sub PSII}>Q{sub P}>PHI{sub PSII}>CAT, GR>Pigment>APO>Growth. For S. obliquus, this ranking was as follows: CAT>Oxygen emission>Q{sub P}>APO>GR>Pigment>PHIs{sub PSII}>Growth>PHI{sub PSII}>Q{sub N} (from the greatest to the least sensitive). The results demonstrated that the observed toxicity is related not only to interspecific variations but also to the selected parameter.

  11. Comparison of different physiological parameter responses in Lemna minor and Scenedesmus obliquus exposed to herbicide flumioxazin

    International Nuclear Information System (INIS)

    Geoffroy, Laure; Frankart, Cecile; Eullaffroy, Philippe

    2004-01-01

    The sensitivity of different physiological parameters in Scenedesmus obliquus and Lemna minor exposed to herbicide (flumioxazin) was investigated to indicate the most convenient and sensitive parameter. To assess toxicity of flumioxazin, we used a panel of biomarkers: pigment contents, chlorophyll fluorescence parameters and antioxidative enzyme activities. Algae and duckweed were exposed to 48-h IC 50 for growth rate. In L. minor, the sensitivity of the parameters was as follows: Q N >Oxygen emission>PHIs PSII >Q P >PHI PSII >CAT, GR>Pigment>APO>Growth. For S. obliquus, this ranking was as follows: CAT>Oxygen emission>Q P >APO>GR>Pigment>PHIs PSII >Growth>PHI PSII >Q N (from the greatest to the least sensitive). The results demonstrated that the observed toxicity is related not only to interspecific variations but also to the selected parameter

  12. Leaching and residual activity of imidazolinone herbicides in lowland soils

    Directory of Open Access Journals (Sweden)

    João Paulo Refatti

    Full Text Available ABSTRACT: Herbicides used in the Clearfield® rice (Oryza sativa L. production system have a potential for leaching. This can result in contamination of underground water resources and cause injury to not tolerant crops that are sown in a succession and/or crop rotation. The objective of this study was to determine the leaching potential and the residual activity of the herbicides used in the Clearfield® rice system. The experiment was conducted over a period of two years and consisted of conducting a field test to be followed by two bioassays with a year of difference between their implementation. Initially an experiment was conducted in lowland area where it was planted the cultivar of rice ‘PUITA INTA CL’. Approximately one and two years thereafter, soil samples from each plot were collected at intervals of 5cm to a depth of 30cm (B factor for the bioassay to evaluate persistence of herbicides. Factor A was composed of mixtures formulated of imazethapyr + imazapic (75 + 25g a.i. L-1, imazapyr + imazapic (525 + 175g a.i. kg-1 in two doses, imazethapyr (100g a.i. L-1 and treatment control without application. Basing on results, it was concluded that the mixtures imazethapyr + imazapic, imazapyr + imazapic and imazethapyr leached into the soil, reaching depths of up to 25cm in lowland soil. Imidazolinone herbicides used today in the irrigated rice Clearfield® system are persistent in soil, and their phytotoxic activity can be observed up to two years after application.

  13. Environmental Statement. Disposition of Orange Herbicide by Incineration

    Science.gov (United States)

    1974-11-01

    remote as possible from both residential and industrial population centers and from land currently in agronomic pro- duction., Vegetation should be...sparse, of little agronomic value, and of species resistant to the phenoxyacetic acid herbicides contained in Orange or to the pyrolytic products of...each to induce intoxication . The above results are summarized in Table 11-7. b. Behavior in Humans: Gehring et al., (1973) studied the effects of 2,4,5-T

  14. Hydrolysis of benzonitrile herbicides by soil actinobacteria and metabolite toxicity

    Czech Academy of Sciences Publication Activity Database

    Veselá, Alicja Barbara; Franc, M.; Pelantová, Helena; Kubáč, David; Vejvoda, Vojtěch; Šulc, Miroslav; Bhalla, T. C.; Macková, M.; Lovecká, P.; Janů, P.; Demnerová, K.; Martínková, Ludmila

    2011-01-01

    Roč. 22, č. 6 (2011), s. 761-770 ISSN 0923-9820 R&D Projects: GA MPO FT-TA5/043; GA MŠk OC09046; GA MŠk(CZ) LC06010; GA AV ČR IAA500200708; GA ČR GD305/09/H008 Institutional research plan: CEZ:AV0Z50200510 Keywords : nitrilase * benzonitrile herbicides * chloroxynil Subject RIV: CE - Biochemistry Impact factor: 2.017, year: 2011

  15. Hydrolysis of benzonitrile herbicides by soil actinobacteria and metabolite toxicity

    Czech Academy of Sciences Publication Activity Database

    Veselá, Alicja Barbara; Franc, M.; Pelantová, Helena; Kubáč, David; Vejvoda, Vojtěch; Šulc, Miroslav; Bhalla, T. C.; Macková, M.; Lovecká, P.; Janů, P.; Demnerová, K.; Martínková, Ludmila

    2010-01-01

    Roč. 21, č. 5 (2010), s. 761-770 ISSN 0923-9820 R&D Projects: GA MPO FT-TA5/043; GA MŠk OC09046; GA MŠk(CZ) LC06010; GA AV ČR IAA500200708; GA ČR GD305/09/H008 Institutional research plan: CEZ:AV0Z50200510 Keywords : Benzonitrile herbicides * nitrilase * Chloroxynil Subject RIV: EE - Microbiology, Virology Impact factor: 2.012, year: 2010

  16. Minimising visitor impacts to protected areas: The efficacy of low impact education programmes

    Science.gov (United States)

    Marion, J.L.; Reid, S.E.

    2007-01-01

    Protected area managers, tourism providers, and other organisations commonly employ education programmes to address visitation-related impairment of natural and cultural resources, social conditions, and neighbouring communities. These programmes have different names (Leave No Trace, Codes of Conduct, Environmental Guidelines for Tourists) but share common objectives: to sustain opportunities for high quality visitor experiences while avoiding or minimising associated negative impacts to protected area resources, visitor experiences, and park neighbours. Theoretical and empirical research studies in the United States are reviewed to evaluate the efficacy of educational efforts that seek to encourage adoption of low impact behaviours. Findings reveal that most of the visitor education efforts evaluated did effectively alter visitor knowledge, behaviour and/or resource and social conditions in the intended direction. These findings, including discussions of message content, delivery, audience characteristics and theoretical grounding, provide insights for improving the efficacy of future educational efforts.

  17. The effect of the herbicide diuron on soil microbial activity.

    Science.gov (United States)

    Prado, A G; Airoldi, C

    2001-07-01

    The inhibitory effect of the herbicide diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] on microbial activity in red Latosol soil was followed using microcalorimetry. The activity of the micro-organisms in 1.50 g of soil sample was stimulated by addition of 6.0 mg of glucose and 6.0 mg of ammonium sulfate under 35% controlled humidity at 298.15 (+/- 0.02) K. This activity was determined by power-time curves that were recorded for increasing amounts of diuron, varying from zero to 333.33 micrograms g-1 soil. An increase in the amount of diuron in soil caused a decrease of the original thermal effect, to reach a null value above 333.33 micrograms g-1 of herbicide. The power-time curve showed that the lag-phase period and peak time increased with added herbicide. The decrease of the thermal effect evolved by micro-organisms and the increase of the lag-phase period are associated with the death of microbial populations caused by diuron, which strongly affects soil microbial communities.

  18. A glutathione s-transferase confers herbicide tolerance in rice

    Directory of Open Access Journals (Sweden)

    Tingzhang Hu

    2014-07-01

    Full Text Available Plant glutathione S-transferases (GSTs have been a focus of attention due to their role in herbicide detoxification. OsGSTL2 is a glutathione S-transferase, lambda class gene from rice (Oryza sativa L.. Transgenic rice plants over-expressing OsGSTL2 were generated from rice calli by the use of an Agrobacterium transformation system, and were screened by a combination of hygromycin resistance, PCR and Southern blot analysis. In the vegetative tissues of transgenic rice plants, the over-expression of OsGSTL2 not only increased levels of OsGSTL2 transcripts, but also GST and GPX expression, while reduced superoxide. Transgenic rice plants also showed higher tolerance to glyphosate and chlorsulfuron, which often contaminate agricultural fields. The findings demonstrate the detoxification role of OsGSTL2 in the growth and development of rice plants. It should be possible to apply the present results to crops for developing herbicide tolerance and for limiting herbicide contamination in the food chain.

  19. Fluridone: a combination germination stimulant and herbicide for problem fields?

    Science.gov (United States)

    Goggin, Danica E; Powles, Stephen B

    2014-09-01

    Problem weeds in agriculture, such as Lolium rigidum Gaud., owe some of their success to their large and dormant seed banks, which permit germination throughout a crop-growing season. Dormant weed seed banks could be greatly depleted by application of a chemical that stimulates early-season germination and then kills the young seedlings. Fluridone, a phytoene desaturase-inhibiting herbicide that can also break seed dormancy, was assessed for its efficacy in this regard. The germination of fluridone-treated Lolium rigidum seeds was stimulated on soils with low organic matter, and almost 100% seedling mortality was observed, while the treatment was only moderately effective on a high-organic-matter potting mix. Seedlings from wheat, canola, common bean and chickpea seeds sown on fluridone-treated sandy loam were bleached and did not survive, but lupins and field peas grew normally. This proof-of-concept study with fluridone suggests that it may be possible to design safe and effective molecules that act as germination stimulants plus herbicides in a range of crop and soil types: a potentially novel way of utilising herbicides to stimulate seed bank germination and a valuable addition to an integrated weed management system. © 2014 Society of Chemical Industry.

  20. Biodegradation of the acetanilide herbicides alachlor, metolachlor, and propachlor.

    Science.gov (United States)

    Stamper, D M; Tuovinen, O H

    1998-01-01

    Alachlor, metolachlor, and propachlor are detoxified in biological systems by the formation of glutathione-acetanilide conjugates. This conjugation is mediated by glutathione-S-transferase, which is present in microorganisms, plants, and mammals. Other organic sulfides and inorganic sulfide also react through a nucleophilic attack on the 2-chloro group of acetanilide herbicides, but the products are only partially characterized. Sorption in soils and sediments is an important factor controlling the migration and bioavailability of these herbicides, while microbial degradation is the most important factor in determining their overall fate in the environment. The biodegradation of alachlor and metolachlor is proposed to be only partial and primarily cometabolic, and the ring cleavage seems to be slow or insignificant. Propachlor biodegradation has been reported to proceed to substantial (> 50%) mineralization of the ring structure. Reductive dechlorination may be one of the initial breakdown mechanisms under anaerobic conditions. Aerobic and anaerobic transformation products vary in their polarity and therefore in soil binding coefficient. A catabolic pathway for chloroacetanilide herbicides has not been presented in the literature because of the lack of mineralization data under defined cultural conditions.

  1. Fate of herbicides in deep subsurface limestone and sandy aquifers

    DEFF Research Database (Denmark)

    Janniche, Gry Sander

    afgørende for at vurdere herbiciders skæbne i underjord og grundvandsmagasiner. PhD-projektet har undersøgt sorption og nedbrydning af fire model-herbicider (atrazin, acetochlor, mecoprop og isoproturon) i kalksten og sandede grundvands¬magasiner. Desuden er den rumlige småskala-variation af herbicidernes...... tydelig selv inden for få cm afstand over dybden, og betydningen af denne variation afhænger af den samlede udbredelse af lag med forhøjet sorption eller nedbrydning; 2) at kalk/kalksten yder ringe beskyttelse mod grundvands¬forurening med mecoprop, atrazin, isoproturon og acetochlor, da sorptionen er lav...... og mineraliseringen meget langsom for isoproturon, acetochlor og mecoprop, og atrazin ikke er nedbrydeligt; 3) at i sandede grundvands¬magasiner er sorptionen af de fire herbicider generelt lav, men kan under reducerede forhold være kraftig for især isoproturon og acetochlor. Mecoprop, isoproturon og...

  2. Microbiological degradation of products for detoxication of chemical weapons and organophosphoric herbicides

    Energy Technology Data Exchange (ETDEWEB)

    Zharikov, G.A. [Research Center for Toxicology and Hygienic Regulation of Biopreparations (RCT and HRB), Serpukhov, Moscow region (Russian Federation); Starovoitov, I.I.; Ermakova, I.T.; Shushkova, T.V. [Inst. for Biochemistry and Physiology of Microorganisms, Pushchino, Moscow region (Russian Federation)

    2003-07-01

    Wide and uncontrolled application of some pesticides, herbicides, and insecticides in agriculture has led to intensive contamination of the environment by phosphoroorganic compounds (PO{sub s}). Development of ecologically sound technologies for bioremediation is an urgent task at cleanup of territories contaminated as a result of implementation of chemical weapons destruction program (toxic agents - TA). Presently, the greatest problem when cleaning the environment is decomposition of PO{sub s} with hardly hydrolyzed direct N-D bond. The bond is resistant to photolysis, chemical hydrolysis, heat degradation and it can be found in many natural and anthropogenic PO{sub s} (methylphosphoric acid (MPA), glyphosate or round-up, phosphonolipids, methylphosphonylfloride, etc.). The goal of the present work is search and selection of highly efficient strains of microorganisms-degraders, hydrolyzing C-P bond in phosphoroorganic compounds for further development of technology for bioremediation of contaminated soils. Microorganisms, capable of hydrolysis of PO{sub s} with direct C-P bond, were isolated from soil samples taken at territories, contaminated by TA detoxication products (sarin, soman), as well as from rice fields subjected to long-term treatment by herbicide glyphosate. Activity of isolated microorganism strains was assessed by the amount of produced biomass as well as by specific growth velocity on the media with mentioned above sources of phosphorus and glutamate as a carbon source. As a result, most active bacteria strains, growing with maximal specific velocity 0.12-0.15 hour{sup -1} and producing biomass 2.0-2.5 g/l were selected. (orig.)

  3. An Epidemiologic Investigation of Health Effects in Air Force Personnel Following Exposure to Herbicides. Volume I: 1997 Follow-up Examination Results

    National Research Council Canada - National Science Library

    Michalek, J

    2000-01-01

    ... attributable to exposure to herbicides exist in veterans of Operation Ranch Hand Operation. Ranch Hand was the unit responsible for the aerial spraying of herbicides, including Herbicide Orange, in Vietnam from 1961 to 1971...

  4. Transgenic and herbicide resistant pearl millet (Pennisetum glaucum L.) R.Br. via microprojectile bombardment of scutellar tissue

    CSIR Research Space (South Africa)

    Girgi, M

    2002-01-01

    Full Text Available systems in cereals. In the early 1990?s genetic transformation using immature embryos as explants was successful in rice (Christou et al. 1991), sorghum (Casas et al. 1993) and wheat (Vasil et al. 1992). Yet, the genetic transformation of pearl millet...). The de- velopment of a low-cost method will form the basis for future genetic enhancement of this crop for the benefit of India and Sub-Saharan Africa. Five geneti- cally independent transgenic plants were identified by selection with the herbicide Basta...

  5. Vasogenic edema in striatum following ingestion of glufosinate-containing herbicide.

    Science.gov (United States)

    Lee, Hui-Young; Song, Seo-Young; Lee, Seung-Hwan; Lee, Seo-Young; Kim, Sung-Hun; Ryu, Sook-Won

    2009-10-01

    Glufosinate-ammonium (GLA) is a broad-spectrum herbicide used worldwide. We report a patient who attempted suicide by ingesting a liquid herbicide containing GLA. A diffusion-weighted MRI showed cytotoxic edema in the hippocampus as well as vasogenic edema in the striata. To our knowledge, vasogenic edema caused by GLA-containing herbicide involving the striatum has not been reported in association with cytotoxic edema in the hippocampus. We assume that this herbicide affected the central nervous system via different mechanisms to produce both cytotoxic and vasogenic edema in the same patient.

  6. Fate of 2,4-D herbicide in soil-plant ecosystems

    International Nuclear Information System (INIS)

    Onal, G.

    1983-01-01

    Herbicide was applied to wheat, barley and oat plants grown under laboratory, greenhouse and field conditions and the fate of the herbicide was investigated using carbon 14 radioisotope. Results of the investigation indicate that (1) under laboratory condition degradation of the herbicide was faster in the soil, rich in organic matter and was not influenced by humidity; (2) the absorption of the herbicide by the plants was low under greenhouse conditions and (3) the uptake of the chemical by the plants grown in the field was higher in the presence of fertilizer (diammonium phosphate)

  7. Effects Of Spring Herbicide Treatments On Winter Wheat Growth And Grain Yield*

    Directory of Open Access Journals (Sweden)

    Hamouz P.

    2015-03-01

    Full Text Available Herbicides provide a low-cost solution for protecting crops from significant yield losses. If weed infestations are below damage thresholds, however, then herbicide application is unnecessary and can even lead to yield loss. A small-plot field trial was conducted to examine the effect of herbicides on winter wheat yields. Weeds were removed manually from the trial area before herbicide application. Twenty-four treatments were tested in four replications. Treatment 1 consisted of an untreated weed-free control, whereas the other treatments comprised applications of the following herbicides and their combinations: metsulfuron-methyl + tribenuron-methyl (4.95 + 9.99 g ha−1, pinoxaden (30 g ha−1, fluroxypyr (175 g ha−1, and clopyralid (120 g ha−1. Water (250 l ha−1 or a urea-ammonium nitrate fertilizer solution (UAN, 120.5 l ha−1 was used as the herbicide carrier. Crop injury 30 days after treatment and yield loss were recorded. Results showed minor crop injury by herbicides and their combinations when applied without UAN and moderate injury caused by UAN in combination with herbicides. Yield losses reached 5.3% and 4.3% in those treatments where all of the tested herbicides were applied with and without UAN, respectively. The effect of all treatments on crop yield was, however, statistically insignificant (P = 0.934.

  8. Acute and additive toxicity of ten photosystem-II herbicides to seagrass.

    Science.gov (United States)

    Wilkinson, Adam D; Collier, Catherine J; Flores, Florita; Negri, Andrew P

    2015-11-30

    Photosystem II herbicides are transported to inshore marine waters, including those of the Great Barrier Reef, and are usually detected in complex mixtures. These herbicides inhibit photosynthesis, which can deplete energy reserves and reduce growth in seagrass, but the toxicity of some of these herbicides to seagrass is unknown and combined effects of multiple herbicides on seagrass has not been tested. Here we assessed the acute phytotoxicity of 10 PSII herbicides to the seagrass Halophila ovalis over 24 and/or 48 h. Individual herbicides exhibited a broad range of toxicities with inhibition of photosynthetic activity (∆F/F(m)') by 50% at concentrations ranging from 3.5 μg l(-1) (ametryn) to 132 μg l(-1) (fluometuron). We assessed potential additivity using the Concentration Addition model of joint action for binary mixtures of diuron and atrazine as well as complex mixtures of all 10 herbicides. The effects of both mixture types were largely additive, validating the application of additive effects models for calculating the risk posed by multiple PSII herbicides to seagrasses. This study extends seagrass ecotoxicological data to ametryn, metribuzin, bromacil, prometryn and fluometuron and demonstrates that low concentrations of PSII herbicide mixtures have the potential to impact ecologically relevant endpoints in seagrass, including ∆F/F(m)'.

  9. Acute and additive toxicity of ten photosystem-II herbicides to seagrass

    Science.gov (United States)

    Wilkinson, Adam D.; Collier, Catherine J.; Flores, Florita; Negri, Andrew P.

    2015-11-01

    Photosystem II herbicides are transported to inshore marine waters, including those of the Great Barrier Reef, and are usually detected in complex mixtures. These herbicides inhibit photosynthesis, which can deplete energy reserves and reduce growth in seagrass, but the toxicity of some of these herbicides to seagrass is unknown and combined effects of multiple herbicides on seagrass has not been tested. Here we assessed the acute phytotoxicity of 10 PSII herbicides to the seagrass Halophila ovalis over 24 and/or 48 h. Individual herbicides exhibited a broad range of toxicities with inhibition of photosynthetic activity (∆F/Fm‧) by 50% at concentrations ranging from 3.5 μg l-1 (ametryn) to 132 μg l-1 (fluometuron). We assessed potential additivity using the Concentration Addition model of joint action for binary mixtures of diuron and atrazine as well as complex mixtures of all 10 herbicides. The effects of both mixture types were largely additive, validating the application of additive effects models for calculating the risk posed by multiple PSII herbicides to seagrasses. This study extends seagrass ecotoxicological data to ametryn, metribuzin, bromacil, prometryn and fluometuron and demonstrates that low concentrations of PSII herbicide mixtures have the potential to impact ecologically relevant endpoints in seagrass, including ∆F/Fm‧.

  10. Herbicidal activity of pre and post emergent herbicide on control of Eleusine indica in aerobic rice system

    International Nuclear Information System (INIS)

    Selvarajh, G.; Zain, N.M.; Aminudin, A.; Seng, C.T.

    2018-01-01

    Aerobic rice system can be an alternate way to cultivate rice in less water conditions. However, weeds are a major constrain in aerobic rice field which decline its success. Weeds are being controlled by herbicides in aerobic rice but not all herbicides are effective in controlling various types of weeds. In this study, two pre-emergent (pretilachor and pendimethalin) and two post-emergent (cyhalofop-butyl and bispyribac-sodium) herbicides were evaluated for effective control of the bioassay species, Eleusine indica. It was found that pendimethalin at a higher application rate of 1.0 kg ai ha-1 strongly inhibit the emergence and shoot growth of E. indica by >75% with negligible effect on the rice growth with stimulation on the leaf greenness. Conversely, pretilachor, cyhalofop-butyl and bispyribac-sodium gave moderate inhibition (55-60% inhibition) on weed emergence and shoot growth at higher application rates of 0.44, 0.1 and 0.035 kg ai ha-1, respectively. Significant inhibitory effects on rice root growth were noticed at highest application rates of pretilachor, cyhalofop-butyl and bispyribac-sodium (40-50% inhibition) across the growth stage of rice seedlings. Great reduction in shoot height, shoot fresh weight, and greenness of rice plant also was evident at 0 DAS across herbicides rates. However, with increasing growth stages, the rice plant became less susceptible to the applied treatments. The finding suggested that pendimethalin at 1.0 kg ai ha-1 was the most suitable application rate for inhibiting E. indica without injuring the rice seedlings. (author)

  11. Glyphosate, other herbicides, and transformation products in Midwestern streams, 2002

    Science.gov (United States)

    Battaglin, W.A.; Kolpin, D.W.; Scribner, E.A.; Kuivila, K.M.; Sandstrom, M.W.

    2005-01-01

    The use of glyphosate has increased rapidly, and there is limited understanding of its environmental fate. The objective of this study was to document the occurrence of glyphosate and the transformation product aminomethylphosphonic acid (AMPA) in Midwestern streams and to compare their occurrence with that of more commonly measured herbicides such as acetochlor, atrazine, and metolachlor. Water samples were collected at sites on 51 streams in nine Midwestern states in 2002 during three runoff events: after the application of pre-emergence herbicides, after the application of post-emergence herbicides, and during harvest season. All samples were analyzed for glyphosate and 20 other herbicides using gas chromatography/mass spectrometry or high performance liquid chromatography/mass spectrometry. The frequency of glyphosate and AMPA detection, range of concentrations in runoff samples, and ratios of AMPA to glyphosate concentrations did not vary throughout the growing season as substantially as for other herbicides like atrazine, probably because of different seasonal use patterns. Glyphosate was detected at or above 0.1 μg/1 in 35 percent of pre-emergence, 40 percent of post-emergence, and 31 percent of harvest season samples, with a maximum concentration of 8.7 μg/1. AMPA was detected at or above 0.1 μg/1 in 53 percent of pre-emergence, 83 percent of post-emergence, and 73 percent of harvest season samples, with a maximum concentration of 3.6 μg/1. Glyphosate was not detected at a concentration at or above the U.S. Environmental Protection Agency's maximum contamination level (MCL) of 700 μg/1 in any sample. Atrazine was detected at or above 0.1 μg/1 in 94 percent of pre-emergence, 96 percent of post-emergence, and 57 percent of harvest season samples, with a maximum concentration of 55 μg/1. Atrazine was detected at or above its MCL (3 μg/1) in 57 percent of pre-emergence and 33 percent of post-emergence samples

  12. Glyphasate, other herbicides, and transformation products in midwestern streams, 2002

    Science.gov (United States)

    Battaglin, William A.; Koplin, Dana W.; Scribner, Elizabeth A.; Kuivila, Kathryn; Sandstrom, Mark W.

    2005-01-01

    The use of glyphosate has increased rapidly, and there is limited understanding of its environmental fate. The objective of this study was to document the occurrence of glyphosate and the transformation product aminomethylphosphonic acid (AMPA) in Midwestern streams and to compare their occurrence with that of more commonly measured herbicides such as acetochlor, atrazine, and metolachlor. Water samples were collected at sites on 51 streams in nine Midwestern states in 2002 during three runoff events: after the application of pre-emergence herbicides, after the application of post-emergence herbicides, and during harvest season. All samples were analyzed for glyphosate and 20 other herbicides using gas chromatography/mass spectrometry or high performance liquid chromatography/mass spectrometry. The frequency of glyphosate and AMPA detection, range of concentrations in runoff samples, and ratios of AMPA to glyphosate concentrations did not vary throughout the growing season as substantially as for other herbicides like atrazine, probably because of different seasonal use patterns. Glyphosate was detected at or above 0.1 μg/1 in 35 percent of pre-emergence, 40 percent of post-emergence, and 31 percent of harvest season samples, with a maximum concentration of 8.7 μg/1. AMPA was detected at or above 0.1 μg/1 in 53 percent of pre-emergence, 83 percent of post-emergence, and 73 percent of harvest season samples, with a maximum concentration of 3.6 μg/1. Glyphosate was not detected at a concentration at or above the U.S. Environmental Protection Agency's maximum contamination level (MCL) of 700 μg/1 in any sample. Atrazine was detected at or above 0.1 μg/1 in 94 percent of pre-emergence, 96 percent of post-emergence, and 57 percent of harvest season samples, with a maximum concentration of 55 μg/1. Atrazine was detected at or above its MCL (3 μg/1) in 57 percent of pre-emergence and 33 percent of post-emergence samples.

  13. Determination of Two Sulfonylurea Herbicides Residues in Soil Environment Using HPLC and Phytotoxicity of These Herbicides by Lentil Bioassay.

    Science.gov (United States)

    Mehdizadeh, Mohammad; Alebrahim, Mohammad Taghi; Roushani, Mahmoud

    2017-07-01

    A HPLC-UV detection system was used for determination of sulfosulfuron and tribenuron methyl residues from soils. The soils were fortified with sulfosulfuron and tribenuron methyl at rates of 26 and 15 g a.i. ha -1 respectively and samples were taken randomly on 0 (2 h), 1, 2, 4, 10, 20, 40, 60, 90 and 120 days after treatment. The final extracts were prepared for analysis by HPLC. The results showed that degradation of both herbicides in the silty loam soil was faster than sandy loam soil. Half-life of sulfosulfuron was ranged from 5.37 to 10.82 days however this value for tribenuron methyl was ranged from 3.23 to 5.72 days on different soils. The residue of both herbicides at 120 days after application in wheat field had no toxicitic effect on lentil. It was concluded that HPLC analysis procedure was an appropriate method for determination of these herbicides from soils.

  14. Simultaneous analysis of herbicides pendimethalin, oxyfluorfen, imazethapyr and quizalofop-p-ethyl by LC-MS/MS and safety evaluation of their harvest time residues in peanut (Arachis hypogaea L.).

    Science.gov (United States)

    Saha, Ajoy; Shabeer T P, Ahammed; Banerjee, Kaushik; Hingmire, Sandip; Bhaduri, Debarati; Jain, N K; Utture, Sagar

    2015-07-01

    This paper reports a simple and rapid method for simultaneous determination of the residues of selected herbicides viz. pendimethalin, oxyfluorfen, imazethapyr and quizalofop-p-ethyl in peanut by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A modified approach of the QuEChERS methodology was used to extract the herbicides from the peanut kernel without any clean-up. The method showed excellent linearity (r(2) > 0.99) with no significant matrix effect. Accuracy of the method in terms of average recoveries of all the four herbicides ranged between 69.4 -94.4 % at spiking levels of 0.05, 0.10 and 0.25 mg kg(-1) with intra-day and inter-day precision RSD (%) between 2.6-16.6 and 8.0-11.3, respectively. Limit of quantification (LOQs) was 5.0 μg kg(-1) for pendimethalin, imazethapyr and quizalofop-p-ethyl and 10.0 μg kg(-1) for oxyfluorfen. The expanded uncertainties were <11 % for determination of these herbicides in peanut. The proposed method was successfully applied for analysis of these herbicide residues in peanut samples harvested from the experimental field and the residues were below the detection level.

  15. ALTERNATIVES TO HERBICIDES IN AN APPLE ORCHARD

    Directory of Open Access Journals (Sweden)

    Cristina Mihaescu

    2015-12-01

    Full Text Available Pesticides have taken a long time the most important place among the means of combating pests. Their use often irrational abusive led to many negative secondary phenomena among which the pollution are the most important. Integrated control requires the use of chemicals especially those selective, with other methods which typically produces the effectiveness of the entire system. Knowledge of pesticides in terms of chemical, biological agricultural and environmental toxicology, have continuously progressed so that the last 40 years have founded a new discipline.

  16. The enzymatic and antioxidative stress response of Lemna minor to copper and a chloroacetamide herbicide.

    Science.gov (United States)

    Obermeier, Michael; Schröder, Christian A; Helmreich, Brigitte; Schröder, Peter

    2015-12-01

    Lemna minor L., a widely used model plant for toxicity tests has raised interest for its application to phytoremediation due to its rapid growth and ubiquitous occurrence. In rural areas, the pollution of water bodies with heavy metals and agrochemicals poses a problem to surface water quality. Among problematic compounds, heavy metals (copper) and pesticides are frequently found in water bodies. To establish duckweed as a potential plant for phytoremediation, enzymatic and antioxidative stress responses of Lemna minor during exposure to copper and a chloroacetamide herbicide were investigated in laboratory studies. The present study aimed at evaluating growth and the antioxidative and glutathione-dependent enzyme activity of Lemna plants and its performance in a scenario for phytoremediation of copper and a chloroacetamide herbicide. Lemna minor was grown in Steinberg medium under controlled conditions. Plants were treated with CuSO4 (ion conc. 50 and 100 μg/L) and pethoxamide (1.25 and 2.5 μg/L). Measurements following published methods focused on plant growth, oxidative stress, and basic detoxification enzymes. Duckweed proved to survive treatment with the respective concentrations of both pollutants very well. Its growth was inhibited scarcely, and no visible symptoms occurred. On the cellular basis, accumulation of O2(-) and H2O2 were detected, as well as stress reactions of antioxidative enzymes. Duckweed detoxification potential for organic pollutants was high and increased significantly with incubation. Pethoxamide was found to be conjugated with glutathione. Copper was accumulated in the fronds at high levels, and transient oxidative defense reactions were triggered. This work confirms the significance of L. minor for the removal of copper from water and the conjugation of the selective herbicide pethoxamide. Both organic and inorganic xenobiotics induced different trends of enzymatic and antioxidative stress response. The strong increase of stress

  17. Degradation of Herbicides in the Tropical Marine Environment: Influence of Light and Sediment.

    Science.gov (United States)

    Mercurio, Philip; Mueller, Jochen F; Eaglesham, Geoff; O'Brien, Jake; Flores, Florita; Negri, Andrew P

    2016-01-01

    Widespread contamination of nearshore marine systems, including the Great Barrier Reef (GBR) lagoon, with agricultural herbicides has long been recognised. The fate of these contaminants in the marine environment is poorly understood but the detection of photosystem II (PSII) herbicides in the GBR year-round suggests very slow degradation rates. Here, we evaluated the persistence of a range of commonly detected herbicides in marine water under field-relevant concentrations and conditions. Twelve-month degradation experiments were conducted in large open tanks, under different light scenarios and in the presence and absence of natural sediments. All PSII herbicides were persistent under control conditions (dark, no sediments) with half-lives of 300 d for atrazine, 499 d diuron, 1994 d hexazinone, 1766 d tebuthiuron, while the non-PSII herbicides were less persistent at 147 d for metolachlor and 59 d for 2,4-D. The degradation of herbicides was 2-10 fold more rapid in the presence of a diurnal light cycle and coastal sediments; apart from 2,4-D which degraded more slowly in the presence of light. Despite the more rapid degradation observed for most herbicides in the presence of light and sediments, the half-lives remained > 100 d for the PS II herbicides. The effects of light and sediments on herbicide persistence were likely due to their influence on microbial community composition and its ability to utilise the herbicides as a carbon source. These results help explain the year-round presence of PSII herbicides in marine systems, including the GBR, but more research on the transport, degradation and toxicity on a wider range of pesticides and their transformation products is needed to improve their regulation in sensitive environments.

  18. Avaliação da eficiência de herbicidas no controle de plantas daninhas em alfafa Decreasing of weed plants using herbicides and herbicides mix in alfalfa crop

    Directory of Open Access Journals (Sweden)

    Wilson da Silva

    2004-08-01

    Full Text Available Objetivou-se neste trabalho avaliar a seletividade e a eficiência de herbicidas no controle de plantas daninhas na cultura da alfafa. Foram desenvolvidos dois experimentos em Anápolis, GO. No primeiro, avaliaram-se oito herbicidas (imazethapyr, MSMA, fomesafen, bentazon, chlorimuron-ethyl, imazamox aplicados em pós-emergência da alfafa, e no segundo, seis misturas de herbicidas [(diuron + MSMA, (diuron + MSMA, (diuron + paraquat, (diuron + paraquat] aplicados um dia após o corte da alfafa. Em ambos os experimentos, foram incluídas duas testemunhas (capinada e sem capina, sendo os tratamentos distribuídos em blocos ao acaso com quatro repetições. Os herbicidas como imazethapyr, MSMA, fomesafen, bentazon, chlorimuron-ethyl e imazamox foram seletivos à cultura da alfafa e eficientes no controle de plantas daninhas. As misturas dos herbicidas (diuron + MSMA e (diuron + paraquat aplicados logo após o corte da alfafa causaram danos às folhas e aos caules remanescentes. As brotações, todavia, surgiram isentas de toxicidade, apresentando crescimento e desenvolvimento normais. Essas misturas promoveram eficiente controle de plantas daninhas, e não afetaram o acúmulo de biomassa seca e altura de plantas em relação à testemunha capinada. O não-controle das plantas daninhas reduziu a produção de biomassa seca e a altura das plantas de alfafa em 74,5% e 42,8%, respectivamente.The objectives of this study were to evaluate the efficiency and selectivity of herbicides on the weed plants control at the alfalfa crop. Two experiments were carried out at the Experimental Station of Agenciarural, located in Anápolis, GO. In the first experiment it was evaluated eight herbicides (imazethapyr, MSMA, fomesafen, bentazon, chlorimuron-ethyl and imazamox post emergency and in the second experiment six different mixed of herbicides [(diuron + MSMA, (diuron + MSMA, (diuron + paraquat, (diuron + paraquat] applied one day after the alfalfa harvesting

  19. Development of Dimensionless Index Assessing Low Impact Development in Urban Areas

    Science.gov (United States)

    Jun, S. H.; Lee, E. H.; Kim, J. H.

    2017-12-01

    Because the rapid urbanization and industrialization have increased the impervious area of watersheds, inundation in urban area and water pollution of river by non-point pollutants have caused serious problems for a long time. Low Impact Development (LID) techniques have been implemented for the solution of these problems due to its cost effectiveness for mitigating the water quality and quantity impact on urban areas. There have been many studies about the effectiveness of LID, but there is a lack of research on developing an index for the assessment of LID performance. In this study, the dimensionless reliability index of LID is proposed. The index is developed using Distance Measure Method (DMM). DMM is used to consider the parameters that have different units. The parameters for reliability of LID are the amount of pollutant at the outfall and the flooding volume. Both parameters become dimensionless index by DMM. Weighted factors in dimensionless index are considered to realize the behavior of reliability for the variation of importance to the parameters. LID is applied to an actual area called Gasan city in Seoul, South Korea where inundation is frequently occurred. The reliability is estimated for 16 different rainfall events. For each rainfall event, the parameters with LID installation are compared with those of no LID installation. Depending on which parameter is considered more important, the results showed difference. In conclusion, the optimal locations of LID are suggested as the weighted factors change.

  20. Closure Report for Corrective Action Unit 107: Low Impact Soil Sites, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    2009-01-01

    Corrective Action Unit (CAU) 107 is identified in the Federal Facility Agreement and Consent Order (FFACO) as 'Low Impact Soil Sites' and consists of the following 15 Corrective Action Sites (CASs), located in Areas 1, 2, 3, 4, 5, 9, 10, and 18 of the Nevada Test Site: CAS 01-23-02, Atmospheric Test Site - High Alt; CAS 02-23-02, Contaminated Areas (2); CAS 02-23-03, Contaminated Berm; CAS 02-23-10, Gourd-Amber Contamination Area; CAS 02-23-11, Sappho Contamination Area; CAS 02-23-12, Scuttle Contamination Area; CAS 03-23-24, Seaweed B Contamination Area; CAS 03-23-27, Adze Contamination Area; CAS 03-23-28, Manzanas Contamination Area; CAS 03-23-29, Truchas-Chamisal Contamination Area; CAS 04-23-02, Atmospheric Test Site T4-a; CAS 05-23-06, Atmospheric Test Site; CAS 09-23-06, Mound of Contaminated Soil; CAS 10-23-04, Atmospheric Test Site M-10; and CAS 18-23-02, U-18d Crater (Sulky). Closure activities were conducted from February through April 2009 according to the FFACO (1996; as amended February 2008) and Revision 1 of the Streamlined Approach for Environmental Restoration Plan for CAU 107 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, 2009). The corrective action alternatives included No Further Action and Closure in Place with Administrative Controls. Closure activities are summarized.

  1. The effect of 8-week low impact aerobic exercise on plasma fibrinogen concentration in old women

    Directory of Open Access Journals (Sweden)

    Shahla Dehghan

    2013-09-01

    Full Text Available Applied Exercise Physiology focuses on the physiological effects of exercise training on physiological processes, health, and physical well-being. The aim of this study was investigation of effects of 8-week low impact aerobic exercise on plasma fibrinogen concentration in old women. Fibrinogen is one of the most important inflammation factors and a prediction index in cardio vascular diseases. Iranian women especially older ones are generally sedentary because of their traditional and religious believes. Samples were 23 healthy and enable to do physical activity old women of Shahrekord (Chaharmahal va bakhtiary province, Iran retirement home. Subjects were randomly divided to two groups including experimental (n=14 individuals and control (n=11 individuals. First, for assessment of fibrinogen level, 5cc blood samples were obtained after 8 hours nightly fasting from anterior vein in resting condition. Experimental group was participated in 8 week (three times a week LIA training program (15 min in first day with 40% of maximum heart rate until 40 min in last day with 65% of maximum heart rate. All of mentioned measurements repeated at the end of 8 week training. The obtained results showed that 8 week LIA program has significant effect on reduction of old women plasma fibrinogen level (P=0.02. It seems that use of 8 week LIA training has positive effects on improvement of cardiovascular health and prevention of inflammation disease related to plasma fibrinogen level in Iranian old women. Key words: aerobic exercises, old women, fibrinogen.

  2. Low-Impact Flooring: Does It Reduce Fall-Related Injuries?

    Science.gov (United States)

    Hanger, H Carl

    2017-07-01

    To compare fall rates and injuries from falls on low-impact flooring (LIF) compared with a standard vinyl flooring. Prospective, observational, nonrandomized controlled study. Subacute Older Persons Health ward (N = 20 beds). Older inpatients. Three different types of LIF. All falls in the ward were prospectively monitored using incident reporting, noting location and consequences of each fall. Fall rates (per 1000 bed days) and injuries, were compared between bedroom falls on LIF against those occurring on standard vinyl flooring (controls). Over 31 months, there were 278 bedroom falls (from 178 fallers). The bedroom fall rate (falls per 1000 bed days occupied) did not differ between the LIF and control groups (median 15 [IQR 8-18] versus 17 [IQR 9-23], respectively; P = .47). However, fall-related injuries were significantly less frequent when they occurred on LIFs (22% of falls versus 34% of falls on control flooring; P = .02). Fractures occurred in 0.7% of falls in the LIF cohort versus 2.3% in the control cohort. Rolling resistance when moving heavier equipment, such as beds or hoists, was an issue for staff on LIF. LIF significantly reduced fall-related injuries compared with a standard vinyl flooring, whereas they did not alter the overall risk of falling. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  3. Evaluation of low impact development approach for mitigating flood inundation at a watershed scale in China.

    Science.gov (United States)

    Hu, Maochuan; Sayama, Takahiro; Zhang, Xingqi; Tanaka, Kenji; Takara, Kaoru; Yang, Hong

    2017-05-15

    Low impact development (LID) has attracted growing attention as an important approach for urban flood mitigation. Most studies evaluating LID performance for mitigating floods focus on the changes of peak flow and runoff volume. This paper assessed the performance of LID practices for mitigating flood inundation hazards as retrofitting technologies in an urbanized watershed in Nanjing, China. The findings indicate that LID practices are effective for flood inundation mitigation at the watershed scale, and especially for reducing inundated areas with a high flood hazard risk. Various scenarios of LID implementation levels can reduce total inundated areas by 2%-17% and areas with a high flood hazard level by 6%-80%. Permeable pavement shows better performance than rainwater harvesting against mitigating urban waterlogging. The most efficient scenario is combined rainwater harvesting on rooftops with a cistern capacity of 78.5 mm and permeable pavement installed on 75% of non-busy roads and other impervious surfaces. Inundation modeling is an effective approach to obtaining the information necessary to guide decision-making for designing LID practices at watershed scales. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. On the sensitivity of geospatial low impact development locations to the centralized sewer network.

    Science.gov (United States)

    Zischg, Jonatan; Zeisl, Peter; Winkler, Daniel; Rauch, Wolfgang; Sitzenfrei, Robert

    2018-04-01

    In the future, infrastructure systems will have to become smarter, more sustainable, and more resilient requiring new methods of urban infrastructure design. In the field of urban drainage, green infrastructure is a promising design concept with proven benefits to runoff reduction, stormwater retention, pollution removal, and/or the creation of attractive living spaces. Such 'near-nature' concepts are usually distributed over the catchment area in small scale units. In many cases, these above-ground structures interact with the existing underground pipe infrastructure, resulting in hybrid solutions. In this work, we investigate the effect of different placement strategies for low impact development (LID) structures on hydraulic network performance of existing drainage networks. Based on a sensitivity analysis, geo-referenced maps are created which identify the most effective LID positions within the city framework (e.g. to improve network resilience). The methodology is applied to a case study to test the effectiveness of the approach and compare different placement strategies. The results show that with a simple targeted LID placement strategy, the flood performance is improved by an additional 34% as compared to a random placement strategy. The developed map is easy to communicate and can be rapidly applied by decision makers when deciding on stormwater policies.

  5. Indicator and Pathogen Removal by Low Impact Development Best Management Practices

    Directory of Open Access Journals (Sweden)

    Jian Peng

    2016-12-01

    Full Text Available Microbial contamination in urban stormwater is one of the most widespread and challenging water quality issues in developed countries. Low impact development (LID best management practices (BMPs restore pre-urban hydrology by treating and/or harvesting urban runoff and stormwater, and can be designed to remove many contaminants including pathogens. One particular type of LID BMP, stormwater biofilters (i.e., vegetated media filters, also known as bioinfiltration, bioretention, or rain gardens, is becoming increasingly popular in urban environments due to its multiple co-benefits (e.g., improved hydrology, water quality, local climate and aesthetics. However, increased understanding of the factors influencing microbial removal in biofilters is needed to effectively design and implement biofilters for microbial water quality improvement. This paper aims to provide a holistic view of microbial removal in biofilter systems, and reviews the effects of various design choices such as filter media, vegetation, infauna, submerged zones, and hydraulic retention time on microbial removal. Limitations in current knowledge and recommendations for future research are also discussed.

  6. Development and Application of a Low Impact Development (LID-Based District Unit Planning Model

    Directory of Open Access Journals (Sweden)

    Cheol Hee Son

    2017-01-01

    Full Text Available The purpose of this study was to develop a low impact development-based district unit planning (LID-DP model and to verify the model by applying it to a test site. To develop the model, we identified various barriers to the urban planning process and examined the advantages of various LID-related techniques to determine where in the urban development process LID would provide the greatest benefit. The resulting model provides (1 a set of district unit planning processes that consider LID standards and (2 a set of evaluation methods that measure the benefits of the LID-DP model over standard urban development practices. The developed LID-DP process is composed of status analysis, comprehensive analysis, basic plan, and sectoral plans. To determine whether the LID-DP model met the proposed LID targets, we applied the model to a test site in Cheongju City, Chungcheongbuk-do Province, Republic of Korea. The test simulation showed that the LID-DP plan reduced nonpoint source pollutants (total nitrogen, 113%; total phosphorous, 193%; and biological oxygen demand, 199%; reduced rainfall runoff (infiltration volume, 102%; surface runoff, 101%; and improved the conservation rate of the natural environment area (132%. The successful application of this model also lent support for the greater importance of non-structural techniques over structural techniques in urban planning when taking ecological factors into account.

  7. Hydraulic characteristics of low-impact development practices in northeastern Ohio, 2008–2010

    Science.gov (United States)

    Darner, Robert A.; Dumouchelle, Denise H.

    2011-01-01

    Low-impact development (LID) is an approach to managing stormwater as near to its source as possible; this is accomplished by minimizing impervious surfaces and promoting more natural infiltration and evapotranspiration than is typically associated with developed areas. Two newly constructed LID sites in northeastern Ohio were studied to document their hydraulic characteristics. A roadside best-management practice (BMP) was constructed by replacing about 1,400 linear feet of existing ditches with a bioswale/rain garden BMP consisting of a grassed swale interspersed with rain-garden/overflow structures. The site was monitored in 2008, 2009, and 2010. Although some overflows occurred, numerous precipitation events exceeding the 0.75-inch design storm did not result in overflows. A second study site consists of an 8,200-square-foot parking lot made of a pervious pavers and a rain garden that receives runoff from the roof of a nearby commercial building. A comparison of data from 2009 and 2010 indicates that the median runoff volume in 2010 decreased relative to 2009. The centroid lag times (time difference between centroid of precipitation and centroid of flow) decreased in 2010, most likely due to more intense, shorter duration precipitation events and maturation of the rain garden. Additional data could help quantify the relation between meteorological variables and BMP efficiency.

  8. Histopathological study on the effect of rice herbicides on grass carp ...

    African Journals Online (AJOL)

    user

    2011-02-14

    Feb 14, 2011 ... observe the impact of herbicides on the histopathology of the fish, the fingerlings were collected from the field trenches ... is almost non-existent in India; the reasons being that increasing ... intensive rice-cum-fish culture offered the opportunity for ..... Toxicity of herbicides to Malaysian rice field fish. In: Proc.

  9. Dynamics of herbicide transport and partitioning under event flow conditions in the lower Burdekin region, Australia

    International Nuclear Information System (INIS)

    Davis, Aaron M.; Lewis, Stephen E.; Bainbridge, Zoë T.; Glendenning, Lionel; Turner, Ryan D.R.; Brodie, Jon E.

    2012-01-01

    This study examined the temporal variability in herbicide delivery to the Great Barrier Reef (GBR) lagoon (Australia) from one of the GBR catchment’s major sugarcane growing regions. Annual loads of measured herbicides were consistently in the order of 200+ kg. Atrazine, it’s degradate desethylatrazine, and diuron contributed approximately 90% of annual herbicide load, with early ‘first-flush’ events accounting for the majority of herbicide loads leaving the catchment. Assessment of herbicide water–sediment partitioning in flood runoff highlighted the majority of herbicides were transported in predominantly dissolved form, although a considerable fraction of diuron was transported in particulate-bound form (ca. 33%). Diuron was also the herbicide demonstrating the highest concentrations and frequency of detection in sediments collected from catchment waterways and adjacent estuarine–marine environments, an outcome aligning with previous research. Herbicide physico-chemical properties appear to play a crucial role in partitioning between water column and sediment habitat types in GBR receiving ecosystems.

  10. A composite transcriptional signature differentiates responses towards closely related herbicides in Arabidopsis thaliana and brassica napus

    Science.gov (United States)

    In this study, genome-wide expression profiling based on Affymetrix ATH1 arrays was used to identify discriminating responses of Arabidopsis thaliana to five herbicides, which contain active ingredients targeting two different branches of amino acid biosynthesis. One herbicide co...

  11. Effects of the herbicides linuron and S-metolachlor on Perez's frog embryos.

    Science.gov (United States)

    Quintaneiro, Carla; Soares, Amadeu M V M; Monteiro, Marta S

    2018-03-01

    Presence of pesticides in the environment and their possible effects on aquatic organisms are of great concern worldwide. The extensive use of herbicides in agricultural areas are one of the factors contributing to the known decline of amphibian populations. Thus, as non-target species, amphibians can be exposed in early life stages to herbicides in aquatic systems. In this context, this study aims to evaluate effects of increasing concentrations of two maize herbicides, linuron and S-metolachlor on embryos of the Perez' frog (Pelophylax perezi) during 192 h. Apical endpoints were determined for each herbicide: mortality, hatching rate, malformations and length. Frog embryos presented a LC 50 of 21 mg/l linuron and 37.5 mg/l S-metolachlor. Furthermore, sub-lethal concentrations of both herbicides affected normal embryonic development, delaying hatching, decreasing larvae length and causing several malformations. Length of larvae decreased with increasing concentrations of each herbicide, even at the lower concentrations tested. Malformations observed in larvae exposed to both herbicides were oedemas, spinal curvature and deformation, blistering and microphtalmia. Overall, these results highlight the need to assess adverse effects of xenobiotics to early life stages of amphibians regarding beside mortality the embryonic development, which could result in impairments at later stages. However, to unravel mechanisms involved in toxicity of these herbicides further studies regarding lower levels of biological organisation such as biochemical and genomic level should be performed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Investigation of 10 herbicides in surface waters of a horticultural production catchment in southeastern Australia.

    Science.gov (United States)

    Allinson, Graeme; Bui, AnhDuyen; Zhang, Pei; Rose, Gavin; Wightwick, Adam M; Allinson, Mayumi; Pettigrove, Vincent

    2014-10-01

    Herbicides are regularly applied in horticultural production systems and may migrate off-site, potentially posing an ecological risk to surface waterways. However, few studies have investigated the levels and potential ecotoxicological impact of herbicides in horticultural catchments in southern Australia. This study investigated the presence of 10 herbicides at 18 sites during a 5-month period in horticulturally important areas of the Yarra Valley in southeastern Australia. Seven of the 10 herbicides were detected in the streams, in 39 % of spot water samples, in 25 % of surface sediment samples, and in >70 % of the passive sampler systems deployed. Few samples contained residues of ≥2 herbicides. Simazine was the herbicide most frequently detected in water, sediment, and passive sampler samples and had the highest concentrations in water (0.67 μg/L) and sediment (260 μg/kg dry weight). Generally the concentrations of the herbicides detected were several orders of magnitude lower than reported ecotoxicological effect values, including those for aquatic plants and algae, suggesting that concentrations of individual chemicals in the catchment were unlikely to pose an ecological risk. However, little is known about the combined effects of simultaneous, low-level exposure of multiple herbicides of the same mode of action on Australian aquatic organisms nor their contribution when found in mixtures with other pesticides. Further research is required to adequately assess the risk of pesticides in Victorian aquatic environments.

  13. GLOBAL EXPRESSION PROFILING AS A TOOL TO DEVELOP MOLECULAR MARKERS LINKED TO HERBICIDE STRESS IN ARABIDOPSIS

    Science.gov (United States)

    Herbicide drift (unintentional physical movement from target to off-target plants) is a cause of crop loss in US. Low-dose, high-potency herbicides that have short environmental persistence times constrain efforts to develop or identify metabolite or biochemical markers of exposu...

  14. Incorporating seeds in activated carbon pellets limits herbicide effects to seeded bunchgrasses when controlling exotic annuals

    Science.gov (United States)

    Revegetation of exotic annual grass-invaded rangeland with pre-emergent herbicides is challenging because seeding is delayed until herbicide toxicity has diminished, but at this time, exotic annuals can be re-invading. Incorporating seeds into activated carbon pellets may allow seeding to occur at t...

  15. Identification and discrimination of herbicide residues using a conducting polymer electronic nose

    Science.gov (United States)

    Alphus Dan Wilson

    2016-01-01

    The identification of herbicide residues on crop foliage is necessary to make crop-management decisions for weed pest control and to monitor pesticide residue levels on food crops. Electronic-nose (e-nose) methods were tested as a cheaper, alternative means of discriminating between herbicide residue types (compared with conventional chromatography methods), by...

  16. NOVEL CHROMATOGRAPHIC SEPARATION AND CARBON SOLID PHASE EXTRACTION OF ACETANILIDE HERBICIDE DEGRADATION PRODUCTS

    Science.gov (United States)

    Six acetanilide herbicides are currently registered for use in the U.S. Over the past several years, ethanesufonic acid (ESA) and oxanilic acid (OA) degradatoin products of these acetanilide herbicides have been found in U.S. ground waters and surface waters. "Alachlor ESA and ...

  17. METHOD DEVELOPMENT FOR ALACHLOR ESA AND OTHER ACENTANILIDE HERBICIDE DEGRADATION PRODUCTS

    Science.gov (United States)

    Introduction: Acetanilide herbicides are frequently applied in the U.S. on crops (corn, soybeans, popcorn, etc.) to control broadleaf and annual weeds. The acetanilide and acetamide herbicides currently registered for use in the U.S. are alachlor, acetochlor, metolachlor, propa...

  18. Controlling herbicide-susceptible, -tolerant and -resistant weeds with microbial bioherbicides

    Science.gov (United States)

    The management of weeds is a necessary but expensive challenge. Public concerns of health, safety, and sustainability have increased interest in reducing the use of synthetic chemicals for weed control. Alternatives to chemical herbicides, such as bioherbicides, may offer an alternative to herbicide...

  19. Laboratory study on leachability of five herbicides in South Australian soils.

    Science.gov (United States)

    Ying, G G; Williams, B

    2000-03-01

    Norflurazon, oxadiazon, oxyfluorfen, trifluralin and simazine are herbicides widely used in the vineyards of the Barossa Valley, South Australia. The leaching behaviour of norflurazon, oxadiazon, oxyfluorfen and trifluralin was investigated on four key soils in the Barossa Valley. Leaching potential on packed soil columns and actual mobility using intact soil columns were investigated. On the packed soil columns, norflurazon was the most leachable herbicide. More of the herbicides were detected in the leachates from the sandy soils (Mountadam and Nuriootpa) than from the clayey soils (Lyndoch and Tanunda). Organic matter is generally low in soils in the Barossa region. Porosity and saturated conductivity significantly affect herbicide movement and in the sandy Mountadam and Nuriootpa soils, the water flux is greater than for the higher clay content Lyndoch and Tanunda soils. Increasing the time interval between herbicide application and the incidence of "rainfall" reduced the amounts of herbicides found in the leachates. The use of intact soil columns and including simazine for comparison showed that both norflurazon and simazine were present in the leachates. Simazine was the first herbicide to appear in leachates. Sectioning of the intact soil columns after leaching clearly demonstrated that norflurazon and simazine reached the bottom of the soil columns for all soils studied. Greater amounts of norflurazon were retained in the soil columns compared with simazine. The other herbicides were mostly retained in the initial sections of the soil columns.

  20. Integration of Agronomic Practices with Herbicides for Sustainable Weed Management in Aerobic Rice

    Science.gov (United States)

    Anwar, M. P.; Juraimi, A. S.; Mohamed, M. T. M.; Uddin, M. K.; Samedani, B.; Puteh, A.; Man, Azmi

    2013-01-01

    Till now, herbicide seems to be a cost effective tool from an agronomic view point to control weeds. But long term efficacy and sustainability issues are the driving forces behind the reconsideration of herbicide dependent weed management strategy in rice. This demands reappearance of physical and cultural management options combined with judicious herbicide application in a more comprehensive and integrated way. Keeping those in mind, some agronomic tools along with different manual weeding and herbicides combinations were evaluated for their weed control efficacy in rice under aerobic soil conditions. Combination of competitive variety, higher seeding rate, and seed priming resulted in more competitive cropping system in favor of rice, which was reflected in lower weed pressure, higher weed control efficiency, and better yield. Most of the herbicides exhibited excellent weed control efficiency. Treatments comprising only herbicides required less cost involvement but produced higher net benefit. On the contrary, treatments comprising both herbicide and manual weeding required high cost involvement and thus produced lower net benefit. Therefore, adoption of competitive rice variety, higher seed rate, and seed priming along with spraying different early-postemergence herbicides in rotation at 10 days after seeding (DAS) followed by a manual weeding at 30 DAS may be recommended from sustainability view point. PMID:24223513

  1. Lawn Weed Control with Herbicides. Home and Garden Bulletin No. 123.

    Science.gov (United States)

    Agricultural Research Service (USDA), Washington, DC.

    Information and diagrams are given for identification and treatment of weed grasses and broadleaf weeds. Herbicides are suggested for use against each weed and instructions are given for proper application. Information is given for buying herbicides, and applying sprays and cleaning sprayers. (BB)

  2. Grassland response to herbicides and seeding of native grasses 6 years posttreatment

    Science.gov (United States)

    Bryan A. Endress; Catherine G. Parks; Bridgett J. Naylor; Steven R. Radosevich; Mark. Porter

    2012-01-01

    Herbicides are the primary method used to control exotic, invasive plants. This study evaluated restoration efforts applied to grasslands dominated by an invasive plant, sulfur cinquefoil, 6 yr after treatments. Of the five herbicides we evaluated, picloram continued to provide the best control of sulfur cinquefoil over 6 yr. We found the timing of picloram...

  3. Questions concerning the potential impact of glyphosate-based herbicides on amphibians.

    Science.gov (United States)

    Wagner, Norman; Reichenbecher, Wolfram; Teichmann, Hanka; Tappeser, Beatrix; Lötters, Stefan

    2013-08-01

    Use of glyphosate-based herbicides is increasing worldwide. The authors review the available data related to potential impacts of these herbicides on amphibians and conduct a qualitative meta-analysis. Because little is known about environmental concentrations of glyphosate in amphibian habitats and virtually nothing is known about environmental concentrations of the substances added to the herbicide formulations that mainly contribute to adverse effects, glyphosate levels can only be seen as approximations for contamination with glyphosate-based herbicides. The impact on amphibians depends on the herbicide formulation, with different sensitivity of taxa and life stages. Effects on development of larvae apparently are the most sensitive endpoints to study. As with other contaminants, costressors mainly increase adverse effects. If and how glyphosate-based herbicides and other pesticides contribute to amphibian decline is not answerable yet due to missing data on how natural populations are affected. Amphibian risk assessment can only be conducted case-specifically, with consideration of the particular herbicide formulation. The authors recommend better monitoring of both amphibian populations and contamination of habitats with glyphosate-based herbicides, not just glyphosate, and suggest including amphibians in standardized test batteries to study at least dermal administration. Copyright © 2013 SETAC.

  4. Histopathological study on the effect of rice herbicides on grass carp ...

    African Journals Online (AJOL)

    Grass carp (Ctenopharyngodan idella) fingerlings were exposed to rice herbicides butachlor 1.5 kg ha-1, oxyfluorfen 0.25 kg ha-1 and thiobencarb 1.5 kg ha-1, 12 days after their application in the respective fields. To observe the impact of herbicides on the histopathology of the fish, the fingerlings were collected from the ...

  5. Downy Brome (Bromus tectorum L. and Broadleaf Weed Control in Winter Wheat with Acetolactate Synthase-Inhibiting Herbicides

    Directory of Open Access Journals (Sweden)

    Patrick W. Geier

    2013-04-01

    Full Text Available A study was conducted for three seasons in northwest Kansas, USA to evaluate acetolactate synthase (ALS-inhibiting herbicides for downy brome (Bromus tectorum L. and winter annual broadleaf weed control in winter wheat. Herbicides included pyroxsulam at 18.4 g ai ha−1, propoxycarbazone-Na at 44 g ai ha−1, premixed propoxycarbazone-Na & mesosulfuron-methyl at 27 g ai ha−1, and sulfosulfuron at 35 g ai ha−1. The herbicides were applied postemergence in fall and spring seasons. Averaged over time of application, no herbicide controlled downy brome more than 78% in any year. When downy brome densities were high, control was less than 60%. Pyroxsulam controlled downy brome greater than or similar to other herbicides tested. Flixweed (Descurainia sophia L., blue mustard [Chorispora tenella (Pallas DC.], and henbit (Lamium amplexicaule L. control did not differ among herbicide treatments. All herbicides tested controlled flixweed and blue mustard at least 87% and 94%, respectively. However, none of the herbicides controlled henbit more than 73%. Fall herbicide applications improved weed control compared to early spring applications; improvement ranged from 3% to 31% depending on the weed species. Henbit control was greatly decreased by delaying herbicide applications until spring compared to fall applications (49% vs. 80% control. Herbicide injury was observed in only two instances. The injury was ≤13% with no difference between herbicides and the injury did not impact final plant height or grain yield.

  6. Forest worker exposure to airborne herbicide residues in smoke from prescribed fires in the Southern United States

    Science.gov (United States)

    Charles K. McMahon; Parshall B. Bush

    1992-01-01

    Occupational safety and health concerns have been raised in a number of southern states by workers conducting prescribed burns on forested lands treated with herbicides. Modeling assessments coupled with laboratory experiments have shown that the risk of airborne herbicide residues to workers is insignificant, even if the fire occurs immediately after herbicide...

  7. Economics of site-specific and variable-dose herbicide application

    DEFF Research Database (Denmark)

    Ørum, Jens Erik; Kudsk, Per; Jensen, Peter Kryger

    2017-01-01

    Site-specific application of pesticides has so far focused mainly on herbicides. The purpose of precision farming technologies in relation to herbicide use is to reduce herbicide cost and environmental impact from spraying, but at the same time to achieve acceptable weed control. Another purpose...... is to increase the spraying capacity, to reduce the number of sprayer refills, and finally to minimize time spent on weed monitoring. In this chapter the relevance and profitability of four precision herbicide application technologies, two weed detection technologies and a low dose decision support system (DSS......) is analysed. With a low dose herbicide, cost can be reduced by 20–50%. It requires, however, proper monitoring of weeds, which can be a time-consuming task that again requires that the farmer is able to identify the dominant weed species. The current development of high-speed camera and software systems can...

  8. Study of different herbicide molecules for the control of durum wheat weed

    Directory of Open Access Journals (Sweden)

    Michele Perniola

    2008-07-01

    Full Text Available In order to enhance the chances to rotate the herbicide molecules, the effectiveness of a new molecule, pinoxaden, was tested, comparing it with other herbicides used in wheat weed control. The trial was carried out comparing the following herbicide mixtures: 1 no weed control treatment; 2 Tribenuron Methyl (TM; 3 Clodinafop (C; 4 Tribenuron Methyl + Clodinafop (TM+C; 5 Pinoxaden + clodinafop + propargile (PCP; 6 Pinoxaden + clodinafop + propargile + Triasulfuron (PCP+T; 7 Pinoxaden + clodinafop + propargile + absolute Ioxinil and Mecoprop (PCP+IM. The new PCP+T herbicides mixture didn’t differ statistically from the traditional TMC treatment in terms of effectiveness, but the agronomic result of the new mixture was totally satisfactory, even taking into account that the marketing of this mixture is not aimed to compete with other existing herbicides but to widen the chance to rotate active principles in time and space, in order to control the onset of resistance phenomena.

  9. Study of different herbicide molecules for the control of durum wheat weed

    Directory of Open Access Journals (Sweden)

    Michele Perniola

    Full Text Available In order to enhance the chances to rotate the herbicide molecules, the effectiveness of a new molecule, pinoxaden, was tested, comparing it with other herbicides used in wheat weed control. The trial was carried out comparing the following herbicide mixtures: 1 no weed control treatment; 2 Tribenuron Methyl (TM; 3 Clodinafop (C; 4 Tribenuron Methyl + Clodinafop (TM+C; 5 Pinoxaden + clodinafop + propargile (PCP; 6 Pinoxaden + clodinafop + propargile + Triasulfuron (PCP+T; 7 Pinoxaden + clodinafop + propargile + absolute Ioxinil and Mecoprop (PCP+IM. The new PCP+T herbicides mixture didn’t differ statistically from the traditional TMC treatment in terms of effectiveness, but the agronomic result of the new mixture was totally satisfactory, even taking into account that the marketing of this mixture is not aimed to compete with other existing herbicides but to widen the chance to rotate active principles in time and space, in order to control the onset of resistance phenomena.

  10. Study of different herbicide molecules for the control of durum wheat weed

    Directory of Open Access Journals (Sweden)

    Vittorio Filì

    2011-02-01

    Full Text Available In order to enhance the chances to rotate the herbicide molecules, the effectiveness of a new molecule, pinoxaden, was tested, comparing it with other herbicides used in wheat weed control. The trial was carried out comparing the following herbicide mixtures: 1 no weed control treatment; 2 Tribenuron Methyl (TM; 3 Clodinafop (C; 4 Tribenuron Methyl + Clodinafop (TM+C; 5 Pinoxaden + clodinafop + propargile (PCP; 6 Pinoxaden + clodinafop + propargile + Triasulfuron (PCP+T; 7 Pinoxaden + clodinafop + propargile + absolute Ioxinil and Mecoprop (PCP+IM. The new PCP+T herbicides mixture didn’t differ statistically from the traditional TMC treatment in terms of effectiveness, but the agronomic result of the new mixture was totally satisfactory, even taking into account that the marketing of this mixture is not aimed to compete with other existing herbicides but to widen the chance to rotate active principles in time and space, in order to control the onset of resistance phenomena.

  11. Screening of photosynthetic pigments for herbicidal activity with a new computational molecular approach.

    Science.gov (United States)

    Krishnaraj, R Navanietha; Chandran, Saravanan; Pal, Parimal; Berchmans, Sheela

    2013-12-01

    There is an immense interest among the researchers to identify new herbicides which are effective against the herbs without affecting the environment. In this work, photosynthetic pigments are used as the ligands to predict their herbicidal activity. The enzyme 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase is a good target for the herbicides. Homology modeling of the target enzyme is done using Modeler 9.11 and the model is validated. Docking studies were performed with AutoDock Vina algorithm to predict the binding of the natural pigments such as β-carotene, chlorophyll a, chlorophyll b, phycoerythrin and phycocyanin to the target. β-carotene, phycoerythrin and phycocyanin have higher binding energies indicating the herbicidal activity of the pigments. This work reports a procedure to screen herbicides with computational molecular approach. These pigments will serve as potential bioherbicides in the future.

  12. EFFECT OF CRUDE CASSAVA WATER EXTRACT AS A NATURAL HERBICIDE ON PROXIMATE COMPOSITION AND BIOACCUMULATION OF HYDROCYANIC ACID IN FOOD COMPONENTS OF COWPEA -VIGNA UNGUICULATA (L WALP

    Directory of Open Access Journals (Sweden)

    Olajumoke Oke FAYINMINNU

    2013-06-01

    Full Text Available This study was a field trial of two experiments to examine the effect of crude cassava water extract (CCWE as a natural post-emergence herbicide on nutritional quality and bioaccumulation of hydrocyanic acid in cowpea seeds. The spraying of CCWE on cowpea plants was carried out weekly for 5weeks. Treatments of CCWE at 25 and 50% concentrations of MS6 (Manihot Selection, TMS30555 (Tropical Manihot Selection and Bulk CCWE (different cassava varieties, hand weeded and unweeded (controls were laid in randomised complete block design with three replications respectively. At maturity, dry samples of cowpea `Ife brown` seeds were ground to fine powder and the proximate composition and bioaccumulation of hydrocyanic acid in the two experiments were determined. Significant variations (p0.05 among the herbicide treatments. It was therefore recommended that CCWE could be used as a natural post-emergence herbicide in cowpea production without altering the nutritional quality and residue of hydrocyanic acid in cowpea seeds.

  13. Manejo da Planta Daninha Brachiaria plantaginea Resistente aos herbicidas Inibidores da ACCase Management of the Weed Brachiaria plantaginea Resistant to ACCase Inhibitor Herbicides

    Directory of Open Access Journals (Sweden)

    P.J. Christoffoleti

    2001-04-01

    study a population of alexandergrass (Brachiaria plantaginea resistant to ACCase inhibitor herbicides (ariloxyphenoxypropionic and cyclohexanodiones, usually sprayed on soybean under the conservation tillage system. Two experiments were conducted, one under field conditions, comparing the efficacy of non-selective herbicides to ACCase inhibitors, and another under greenhouse conditions, using ACCase inhibitors with nitrogenous additives in the spray solution. Resistant seeds were collected from a site of suspected resistant population, and compared to a population of alexandergrass that had never been sprayed with ACCase inhibitors, the susceptible population. The experiment with non-selective herbicides was conducted under field conditions, but plants were confined to pots of 50 L capacity, avoiding the dissemination of the seeds to adjacent areas. It was then concluded that resistant plants did not show multiple resistance to non selective herbicides with alternative mechanisms of action, with glyphosate, paraquat, paraquat + diuron, MSMA and glufosinate alternative herbicides being possible to be used to control the weed during the winter to manage populations of alexandergrass resistant to ACCase inhibitor herbicides. The additive experiment was conducted under greenhouse conditions in pots, using seeds from the same populations used in the non selective experiment. The herbicides tested were ACCase inhibitors, and the additive treatments were ammonium sulfate and urea. It was then concluded that the additives did not enhance ACCase inhibitor herbicide efficacy in neither of the alexandergrass populations.

  14. Sample clean-up, enrichment and determination of s-triazine herbicides from southern ethiopian lakes supported using liquid membrane extraction

    Directory of Open Access Journals (Sweden)

    Jan Åke Jönsson

    2000-06-01

    Full Text Available The liquid membrane extraction method has been employed for selectively extracting trace quantities of s-triazine herbicides in environmental waters collected from lakes Awassa, Chamo and Abbya, located in close proximity to the agricultural farms in Southern Ethiopia. In liquid membrane extraction, the uncharged triazine compounds from the flowing donor solution diffuse through a porous poly(tetrafluoroethylene (PTFE membrane, containing a water immiscible organic solvent. The s-triazine molecules are then irreversibly trapped in the stagnant acidic acceptor phase since they become protonated. Using both di-n-hexylether and n-undecane membrane solvents, s-traizine herbicides were extracted and low detection limits of about 1 ng/L have been obtained by extraction of three liters of sample solution spiked with 0.1 g/L of each triazine. Residues of atrazine and terbutryn ranging in concentration from 0.02 to 0.05 g/L have been successfully determined.

  15. Delayed degradation in soil of foliar herbicides glyphosate and sulcotrione previously absorbed by plants: Consequences on herbicide fate and risk assessment

    OpenAIRE

    Doublet, Jeremy; Mamy, Laure; Barriuso Benito, Enrique

    2009-01-01

    Following application, pesticides can be intercepted and absorbed by weeds and/or crops. Plants containing pesticides residues may then reach the soil during the crop cycle or after harvest. However, the fate in soil of pesticides residues in plants is unknown. Two commonly used foliar herbicides, glyphosate and sulcotrione, 14C-labeled, were applied on leaves of oilseed rape and/or maize, translocation was studied, and then soil incubations of aerial parts of plants containing herbicides res...

  16. DSSHerbicide: Herbicide field trials in winter wheat. How to come to a decision

    Directory of Open Access Journals (Sweden)

    Sefzat, David

    2014-02-01

    Full Text Available Herbicide decision support systems can calculate efficient, economically optimized herbicide mixtures with reduced dosages, if field specific weed data are given. Thus, they can be a sensible tool for integrated weed control. However, advises of decision support systems have to be tested before introducing them into practical farming. In Mecklenburg-Vorpommern two herbicide field trials were installed with four different prototypes of decision support systems. An untreated plot and three expert advices, private advisors, official advisory service and a farmer decision, were included as additional test variables. Herbicide efficacies in autumn, weed dry matter after spring applications, herbicide costs and wheat yield were measured to evaluate the decision support system prototypes. In one field trial with low weed density before treatments efficacies were at least 85%. In two prototypes efficacies were lower than in the expert plots. No significant differences between decision variables were found regarding weed dry matter after spraying in spring. On this site, herbicide costs were higher when expert advises were used compared to decision support system advises. No significant differences were detected in yield. Even yield in “untreated” was not significantly different. The second field trial carried higher weed densities. Here herbicide efficacies were lower in all treatments. Poa annua and Matricaria recutita were significantly affected by the treatments resulting from the decision tools. However, these differences did not result in statistically different weed dry matter or wheat yield. Three of the prototypes advised solutions with very low herbicide costs in autumn, but high costs in spring. As a result, total weed costs in these plots were higher than in the plots advised by experts. It is concluded from the field trials, that different prototypes of decision support systems are giving sensible herbicide advice. In fields with low

  17. Herbicide monitoring in soil, runoff waters and sediments in an olive orchard.

    Science.gov (United States)

    Calderon, Maria Jesus; De Luna, Elena; Gomez, Jose Alfonso; Hermosin, M Carmen

    2016-11-01

    Occurrences of surface water contamination by herbicides in areas where olive orchards are established reveal a need to understand soil processes affecting herbicide fate at field scale for this popular Mediterranean crop. A monitoring study with two herbicides (terbuthylazine and oxyfluorfen) in the first 2cm of soil, runoff waters, and sediments, was carried out after under natural rainfall conditions following winter herbicide application. At the end of the 107day field experiment, no residues of the soil applied terbuthylazine were recovered, whereas 42% of the oxyfluorfen applied remained in the top soil. Very low levels of both herbicides were measured in runoff waters; however, concentrations were slightly higher for terbuthylazine (0.53% of applied) than for oxyfluorfen (0.03% of applied), relating to their respective water solubilities. Congruent with soil residue data, 38.15% of the applied oxyfluorfen was found in runoff-sediment, compared to only 0.46% for terbuthylazine. Accordingly, the herbicide soil distribution coefficients measured within runoff field tanks was much greater for oxyfluorfen (Kd=3098) than for terbuthylazine (Kd=1.57). The herbicide oxyfluorfen is co-transported with sediment in runoff, remaining trapped and/or adsorbed to soil particle aggregates, due in part to its low water solubility. In contrast, terbuthylazine soil dissipation may be associated more so with leaching processes, favored by its high water solubility, low sorption, and slow degradation. By comparing these two herbicides, our results reaffirm the importance of herbicide physico-chemical properties in dictating their behavior in soil and also suggest that herbicides with low solubility, as seen in the case oxyfluorfen, remain susceptible to offsite transport associated with sediments. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Multiple approaches to valuation of conservation design and low-impact development features in residential subdivisions.

    Science.gov (United States)

    Bowman, Troy; Tyndall, John C; Thompson, Janette; Kliebenstein, James; Colletti, Joe P

    2012-08-15

    Residents, developers and civic officials are often faced with difficult decisions about appropriate land uses in and around metropolitan boundaries. Urban expansion brings with it the potential for negative environmental impacts, but there are alternatives, such as conservation subdivision design (CSD) or low-impact development (LID), which offer the possibility of mitigating some of these effects at the development site. Many urban planning jurisdictions across the Midwest do not currently have any examples of these designs and lack information to identify public support or barriers to use of these methods. This is a case study examining consumer value for conservation and low-impact design features in one housing market by using four different valuation techniques to estimate residents' willingness to pay for CSD and LID features in residential subdivisions. A contingent valuation survey of 1804 residents in Ames, IA assessed familiarity with and perceptions of subdivision development and used an ordered value approach to estimate willingness to pay for CSD and LID features. A majority of residents were not familiar with CSD or LID practices. Residents indicated a willingness to pay for most CSD and LID features with the exception of clustered housing. Gender, age, income, familiarity with LID practices, perceptions of attractiveness of features and the perceived effect of CSD and LID features on ease of future home sales were important factors influencing residents' willingness to pay. A hypothetical referendum measured willingness to pay for tax-funded conservation land purchases and estimated that a property tax of around $50 would be the maximum increase that would pass. Twenty-seven survey respondents participated in a subsequent series of experimental real estate negotiations that used an experimental auction mechanism to estimate willingness to pay for CSD and LID features. Participants indicated that clustered housing (with interspersed preserved forest

  19. Toxicity of three selected pesticides (Alachlor, Atrazine and Diuron ...

    African Journals Online (AJOL)

    The present study aimed to evaluate acute toxicity tests for three selected herbicides: Alachlor, Atrazine and Diuron using turbot flatfish. Larvae were more sensitive than turbot embryos to all pesticides. Median lethal concentrations of the selected pesticides during a 48 h and 96 h exposure for turbot embryos and larvae ...

  20. A Meta-Analysis of Hedonic Studies to Assess the Property Value Effects of Low Impact Development

    Science.gov (United States)

    Stormwater runoff from urban areas is a significant source of water pollution in the United States. Many states are promoting low impact development (LID) practices, which provide a variety of direct and ancillary ecosystem services. We describe a meta-analysis designed to evalua...

  1. Progress in herbicide determination with the thylakoid bioassay.

    Science.gov (United States)

    Trapmann, S; Etxebarria, N; Schnabl, H; Grobecker, K H

    1998-01-01

    Chloroplast thylakoids are used as biological units to determine herbicides in different kinds of water samples as well as in aqueous extracts of compost, soil or food samples. The thylakoid bioassay shows clearly inhibition of fluorescence yield in the presence of photosystem II specific herbicides. Due to this method the ecotoxicological effect of samples with unknown pollutants can be tested fast and cost effective. It has been proven that all photosynthetic active compounds are recorded at the same time because only additive interactions occur. Therefore, the contamination level can be expressed as cumulative parameter for photosystem II active substances. Application was improved clearly by the addition of the radical scavenger sodium ascorbate to the isolation media and by a higher concentration of the measuring medium. A new data evaluation method is described yielding in a lower detection limit of 0.4 microg diuron/1. The guidelines for the quality of water for human consumption with an allowable concentration of pesticides in groups is 0,5 microg/1 and can be controlled with the thylakoid bioassay without performing any preconcentration steps.

  2. Herbicidal and Fungicidal Activities of Lactones in Kava (Piper methysticum).

    Science.gov (United States)

    Xuan, T D; Elzaawely, A A; Fukuta, M; Tawata, S

    2006-02-08

    This is the first report showing that kava lactones are plant and plant fungus growth inhibitors. Aqueous extract of kava roots showed high allelopathic potential and strongly suppressed germination and growth of lettuce, radish, barnyardgrass, and monochoria. Nine kava lactones were detected using GC-MS including desmethoxyyagonin, kavain, 7,8-dihydrokavain, hydroxykavain, yagonin, 5,6,7,8-tetrahydroxyyagonin, methysticin, dihydromethysticin, and 11-hydroxy-12-methoxydihydrokavain. Quantities of desmethoxyyagonin, kavain, 7,8-dihydrokavain, yagonin, methysticin, and dihydromethysticin detected were 4.3, 6.9, 18.6, 5.7, 1.4, and 5.4 mg/g of dry weight, respectively. These six major lactones in kava roots showed great herbicidal and antifungal activities. Growth of lettuce and barnyardgrass were significantly inhibited at 1-10 ppm, and four plant fungi including Colletotrichum gloeosporides, Fusarium solani, Fusarium oxysporum, and Trichoderma viride were significantly inhibited at 10-50 ppm. The biological activities of kava lactones were characterized by different double-bond linkage patterns in positions 5,6 and 7,8. The findings of this study suggest that kava lactones may be useful for the development of bioactive herbicides and fungicides.

  3. Developmental toxicity of diphenyl ether herbicides in nestling American kestrels.

    Science.gov (United States)

    Hoffman, D J; Spann, J W; LeCaptain, L J; Bunck, C M; Rattner, B A

    1991-11-01

    Beginning the day after hatching, American kestrel (Falco sparverius) nestlings were orally dosed for 10 consecutive days with 5 microliters/g of corn oil (controls) or one of the diphenyl ether herbicides (nitrofen, bifenox, or oxyfluorfen) at concentrations of 10, 50, 250, or 500 mg/kg in corn oil. At 500 mg/kg, nitrofen resulted in complete nestling mortality, bifenox in high (66%) mortality, and oxyfluorfen in no mortality. Nitrofen at 250 mg/kg reduced nestling growth as reflected by decreased body weight, crown-rump length, and bone lengths including humerus, radius-ulna, femur, and tibiotarsus. Bifenox at 250 mg/kg had less effect on growth than nitrofen, but crown-rump, humerus, radius-ulna, and femur were significantly shorter than controls. Liver weight as a percent of body weight increased with 50 and 250 mg/kg nitrofen. Other manifestations of impending hepatotoxicity following nitrofen ingestion included increased hepatic GSH peroxidase activity in all nitrofen-treated groups, and increased plasma enzyme activities for ALT, AST, and LDH-L in the 250-mg/kg group. Bifenox ingestion resulted in increased hepatic GSH peroxidase activity in the 50- and 250-mg/kg groups. Nitrofen exposure also resulted in an increase in total plasma thyroxine (T4) concentration. These findings suggest that altricial nestlings are more sensitive to diphenyl ether herbicides than young or adult birds of precocial species.

  4. Application of electrokinetic soil flushing to four herbicides: A comparison.

    Science.gov (United States)

    dos Santos, E Vieira; Souza, F; Saez, C; Cañizares, P; Lanza, M R V; Martinez-Huitle, C A; Rodrigo, M A

    2016-06-01

    In this work, four bench-scale plants containing soil spiked with four herbicides (2,4-Dichlorophenoxyacetic acid (2,4-D), oxyfluorfen, chlorsulfuron and atrazine) undergo treatment consisting of an electrokinetic soil flushing (EKSF). Results clearly demonstrate that efficiency of EKSF depends on the chemical characteristic of the pesticide used. The amount of pesticide collected in the anode well is more significant than that collected in the cathode wells, indicating that the electromigration is much more important than drainage by electro-osmotic flux for this application. After 15 d of treatment, the 2,4-D is the pesticide most efficiently removed (95% of removal), while chlorsulfuron is the pesticide more resilient to the treatment. Additionally, volatilization was found to be a process of the major significance in the application of electrokinetic techniques to soil polluted with herbicides and because of that it should always be taken into account in the future design of full-scale processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. PREVENTION AND CONTROL OF DIMETHYLAMINE VAPORS EMISSION: HERBICIDE PRODUCTION PLANT

    Directory of Open Access Journals (Sweden)

    Zorana Arsenijević

    2008-11-01

    Full Text Available The widely used herbicide, dimethylamine salt of 2,4-dichlorophenoxy acetic acid (2,4-D-DMA, is usually prepared by mixing a dimethylamine (DMA aqueous solution with a solid 2,4-dichlorophenoxy acetic acid (2,4-D. The vapors of the both, reactants and products, are potentially hazardous for the environment. The contribution of DMA vapors in overall pollution from this process is most significant, concerning vapor pressures data of these pollutants. Therefore, the control of the air pollution in the manufacture and handling of methylamines is very important. Within this paper, the optimal air pollution control system in preparation of 2,4-D-DMA was developed for the pesticides manufacturing industry. This study employed the simple pollution prevention concept to reduce the emission of DMA vapors at the source. The investigations were performed on the pilot plant scale. To reduce the emission of DMA vapors, the effluent gases from the herbicide preparation zone were passed through the packed bed scrubber (water - scrubbing medium, and the catalytic reactor in sequence. The end result is a substantially improved air quality in the working area, as well as in the urbanized areas located near the chemical plant.

  6. Magnetic polyethyleneimine functionalized reduced graphene oxide as a novel magnetic solid-phase extraction adsorbent for the determination of polar acidic herbicides in rice

    International Nuclear Information System (INIS)

    Li, Na; Chen, Juan; Shi, Yan-Ping

    2017-01-01

    .94%. Taken together, the proposed method was an efficient pretreatment and enrichment procedure and could be successfully applied for selective extraction and determination of polar acidic herbicides in complex matrices. - Highlights: • A novel Fe 3 O 4 @PEI-RGO was synthesized and applied for the analysis of polar acidic herbicides. • PEI affected the surface property of RGO and changed the polarity of RGO. • Fe 3 O 4 @PEI-RGO showed good extraction efficiency towards polar acidic herbicides. • RSM was used to optimize parameters affecting the extraction efficiency. • The absorption mechanism was discussed in detail.

  7. The Effect of Herbicides on Hydrogen Peroxide Generation in Isolated Vacuoles of Red Beet Root (Beta vulgaris L.

    Directory of Open Access Journals (Sweden)

    E.V. Pradedova

    2015-12-01

    Full Text Available Influence of herbicides on the hydrogen peroxide generation in vacuolar extracts of red beet root (Beta vulgaris L. was investigated. Belonging to different chemical classes of herbicide compounds have been used. Herbicides differ from each other in the mechanism of effects on plants. Clopyralid (aromatic acid herbicide, derivative of picolinic acid and 2.4-D (phenoxyacetic herbicide, characterized by hormone-like effects, contributed to the formation of H2O2 in vacuolar extracts. Fluorodifen (nitrophenyl ether herbicide and diuron (urea herbicide also have increased contents H2O2. These compounds inhibit the electron transport, photosynthesis, and photorespiration in sensitive plants. Herbicidal effect of glyphosate (organophosphorus herbicide is due to the inhibition of amino acid synthesis in plant cells. Glyphosate did not affect the content of H2O2 in vacuolar extracts. Herbicide dependent H2O2-generation did not occur with oxidoreductase inhibitors, potassium cyanide and sodium azide. The results suggest that the formation of ROS in the vacuoles due to activity of oxidoreductases, which could interact with herbicides.

  8. Phytotoxicity of chiral herbicide bromacil: Enantioselectivity of photosynthesis in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Chen, Zunwei; Zou, Yuqin; Wang, Jia; Li, Meichao; Wen, Yuezhong

    2016-01-01

    With the wide application of chiral herbicides and the frequent detection of photosystem II (PSII) herbicides, it is of great importance to assess the direct effects of PSII herbicides on photosynthesis in an enantiomeric level. In the present study, the enantioselective phytotoxicity of bromacil (BRO), typical photosynthesis inhibition herbicide, on Arabidopsis thaliana was investigated. The results showed that S-BRO exhibited a greater inhibition of electron transmission in photosystem I (PSI) of A. thaliana than R-BRO by inhibiting the transcription of fnr 1. S-BRO also changed the chlorophyll fluorescence parameters Y (II), Y (NO), and Y (NPQ) to a greater extent than R-Bro. Transcription of genes psbO2, Lhcb3 and Lhcb6 was down-regulated in an enantioselective rhythm and S-BRO caused more serious influence, indicating that S-BRO did worse damage to the photosystem II (PSII) of A. thaliana than R-BRO. This study suggested that S-BRO disturbed the photosynthesis of plants to a larger extent than R-BRO and provided a new sight to evaluate the phytotoxicity of chiral herbicides. - Highlights: • It is necessary to assess the direct effects of PSII herbicides on photosynthesis. • Phytotoxicity of bromacil is investigated in an enantiomeric level. • Bromacil disturbed enantioselectively the photosystem II of Arabidopsis thaliana. • S-bromacil caused severer damage to photosynthesis of Arabidopsis than R-bromacil. • Photosynthesis should be considered for phytotoxicity assessment of herbicides.

  9. Efficacy of Maister OD (Foramsulfuron + Idosulfuron a New Herbicide in Controlling Weeds of Corn Fields

    Directory of Open Access Journals (Sweden)

    J. Abdi

    2012-07-01

    Full Text Available To evaluate the efficacy of a new herbicide Foramsulfuron +Idosulfuron (Maister OD against other herbicides in corn fields, this experiment was fulfielld in 2010 at Mahidasht, Research Center of Agriculture and Natural Resources of Kermanshah, Iran. It was concucted in randomized complete block design with four replications and 11 treatments. In this experiment, three doses of herbicides (38.75, 46.5 and 54.25 g/ha including foramsulfuron + idosulfuron along with Nicusulfuron, ForamSulfuron, Rimsulfuron, Foramsulfuron + Rimsulfuron , Bromicid + hand weeding narrow leaf weeds, Bromicid + Nicusulfuron and U46 + hand weeding of narrow leaf weeds and a complete weeding as the control treatments were investigated. Weeds present in the field were Xanthium stromarium,Chenopedium album, Portulaca oleracea, Sorgum halepense and Setaria virdis. The results of this study showed that doses 38.75 and 46.5 g/ha of herbicide foramsulfuron + idosulfuron after treatments of Bromicid + Nicusulfuron and, Bromicid + narrow leaf weed, hand weeding respectively could control 90 and 86 % of weeds in corn field and increase its yields significantly. Because there are presently few registered herbicide available in Iran, necessity of finding proper herbicides to control weeds in corn field and based on the results oblained from this experiment it seems using 46.5 and 38-75 grams per hectare respectively of foramsulfuron + idosulfuron could be a better option than other herbicides to control weeds in corn fields and increase its seed yield.

  10. Persistence of auxinic herbicides applied on pasture and toxicity for succeeding crops

    Directory of Open Access Journals (Sweden)

    ARNON H.C. ANÉSIO

    2018-04-01

    Full Text Available ABSTRACT The aim of this work was to determine the persistence of auxinic herbicides applied on tropical pasture and toxicity for succeeding crops. The herbicides were applied in an area of dystrophic red‒yellow latosol with pasture infested of weeds. At 40, 80, and 280 days after application of herbicide, the soil samples were collected at depths of 0 to 20 cm. Soil with residues of 2,4-D, 2,4-D + picloram, triclopyr, and a soil without herbicide application were analyzed with six replicates. Seven crops were cultivated in these soils: cucumber (Cucumis sativus L., velvet bean [Mucuna pruriens (L. DC.], pigeon pea [Cajanus cajan (L. Millsp.], alfalfa (Medicago sativa L., lablab bean [Lablab purpureus (L. Sweet], corn (Zea mays L., and sorghum [Sorghum bicolor (L. Moench]. The plants of cucumber, pigeon pea, and alfalfa were the most susceptible to the auxinic herbicide residues. However, the lablab bean was the only one among the dicot evaluated that showed tolerance to the 2,4-D + picloram residual when cultivated in soils at 280 days after application of herbicide. Corn and sorghum showed lower chlorophyll content in soils with 2,4-D + picloram residual up to 80 days after application of herbicide.

  11. Phytotoxicity of four herbicides on Ceratophyllum demersum, Vallisneria natans and Elodea nuttallii.

    Science.gov (United States)

    Pan, Huiyun; Li, Xiaolu; Xu, Xiaohua; Gao, Shixiang

    2009-01-01

    The physiological effects of 4 herbicides (butachlor, quinclorac, bensulfuron-methyl and atrazine) on 3 submerged macrophytes (Ceratophyllum demersum, Vallisneria natans and Elodea nuttallii) were tested in laboratory. The variables of the relative growth rate and the photosynthetic pigment content showed that all of the tested herbicides affected the growth of the plants obviously, even at the lowest concentration (0.0001 mg/L). Except for the C. demersum treated with quinclorac at 0.005 and 0.01 mg/L, the relative growth rates of the plants were inhibited significantly (p < 0.01). Statistical analysis of chlorophyll a (Chl-a) contents was carried out with both the t-test and one-way ANOVA to determine the difference between the treatment and control. The results showed that Chl-a contents of the plants in all treatment groups were affected by herbicides significantly, except for the C. demersum treated with bensulfuron-methyl at 0.0005 mg/L. The decrease in Chl-a content was positively correlated to the dosage of the herbicides in most treatment groups. It was suggested that herbicides in water bodies might potentially affect the growth of aquatic macrophytes. Since the Chl-a content of submerged macrophytes responded to the stress of herbicides sensitively and directly, it could be used as a biomaker in environmental monitoring or in the ecological risk assessment of herbicide contamination.

  12. Phytotoxicity of chiral herbicide bromacil: Enantioselectivity of photosynthesis in Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zunwei; Zou, Yuqin; Wang, Jia [MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Li, Meichao [Research Center of Analysis and Measurement, Zhejiang University of Technology, Hangzhou 310032 (China); Wen, Yuezhong, E-mail: wenyuezhong@zju.edu.cn [MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China)

    2016-04-01

    With the wide application of chiral herbicides and the frequent detection of photosystem II (PSII) herbicides, it is of great importance to assess the direct effects of PSII herbicides on photosynthesis in an enantiomeric level. In the present study, the enantioselective phytotoxicity of bromacil (BRO), typical photosynthesis inhibition herbicide, on Arabidopsis thaliana was investigated. The results showed that S-BRO exhibited a greater inhibition of electron transmission in photosystem I (PSI) of A. thaliana than R-BRO by inhibiting the transcription of fnr 1. S-BRO also changed the chlorophyll fluorescence parameters Y (II), Y (NO), and Y (NPQ) to a greater extent than R-Bro. Transcription of genes psbO2, Lhcb3 and Lhcb6 was down-regulated in an enantioselective rhythm and S-BRO caused more serious influence, indicating that S-BRO did worse damage to the photosystem II (PSII) of A. thaliana than R-BRO. This study suggested that S-BRO disturbed the photosynthesis of plants to a larger extent than R-BRO and provided a new sight to evaluate the phytotoxicity of chiral herbicides. - Highlights: • It is necessary to assess the direct effects of PSII herbicides on photosynthesis. • Phytotoxicity of bromacil is investigated in an enantiomeric level. • Bromacil disturbed enantioselectively the photosystem II of Arabidopsis thaliana. • S-bromacil caused severer damage to photosynthesis of Arabidopsis than R-bromacil. • Photosynthesis should be considered for phytotoxicity assessment of herbicides.

  13. Runoff of the herbicides triclopyr and glufosinate ammonium from oil palm plantation soil.

    Science.gov (United States)

    Tayeb, M A; Ismail, B S; Khairiatul-Mardiana, J

    2017-10-11

    This study focused on the residue detection of the herbicides triclopyr and glufosinate ammonium in the runoff losses from the Tasik Chini oil palm plantation area and the Tasik Chini Lake under natural rainfall conditions in the Malaysian tropical environment. Triclopyr and glufosinate ammonium are post-emergence herbicides. Both herbicides were foliar-sprayed on 0.5 ha of oil palm plantation plots, which were individualized by an uneven slope of 10-15%. Samples were collected at 1, 3, 7, 15, 30, 45, 60, 90, and 120 days after treatment. The concentrations of both herbicides quickly diminished from those in the analyzed sample by the time of collection. The highest residue levels found in the field surface leachate were 0.031 (single dosage, triclopyr), 0.041 (single dosage, glufosinate ammonium), 0.017 (double dosage, triclopyr), and 0.037 μg/kg (double dosage, glufosinate ammonium). The chromatographic peaks were observed at "0" day treatment (2 h after herbicide application). From the applied active ingredients, the triclopyr and glufosinate losses were 0.025 and 0.055%, respectively. The experimental results showed that both herbicides are less potent than other herbicides in polluting water systems because of their short persistence and strong adsorption onto soil clay particles.

  14. Hygienic assessment of risk caused by application of graminis ke and rinkor vg herbicides

    Directory of Open Access Journals (Sweden)

    M.M. Vasileva

    2017-12-01

    Full Text Available Our research goal was to perform hygienic assessment of risks caused by Graminis KE and Rinkor VG herbicides for people working with them. We applied sanitary-hygienic and toxicological research techniques in our work in full conformity with valid technical regulatory documents and guidelines. We set the following research tasks: to analyze literature and information sources; to perform primary toxicological assessment of preparatory herbicides and study their acute toxicity together with sensitizing effects at intragastric introduction, cutaneous application, and inhalation exposure on laboratory animals; to examine herbicides cumulative effects and calculation their cumulation coefficient; to examine working conditions during a natural experiment when Graminis KE and Rinkor VG herbicides were applied and calculate risks for workers; to work out scientifically grounded recommendations on their safety application in agriculture. The examined herbicides, Graminis KE and Rinkor VG, are classified as substances with the 3rd hazard degree as per their toxicometric parameters (moderately hazardous substances. Calculated risks of complex (inhalant and dermal exposure to Gramins KE and Rinkor VG herbicides for workers (operators who refills them and those who spray plants with them when they are applied in agriculture don't exceed acceptable levels (are less than 1. Our work results allow to enrich a set of plant protectors which are applied in the country and to use such preparations in agriculture which are the least harmful for health and the environment. Application of Graminis KE and Rinkor VG herbicides will help to increase crops productivity.

  15. Development of antibiotic marker-free creeping bentgrass resistance against herbicides.

    Science.gov (United States)

    Lee, Ki-Won; Kim, Ki-Yong; Kim, Kyung-Hee; Lee, Byung-Hyun; Kim, Jin-Seog; Lee, Sang-Hoon

    2011-01-01

    Herbicide-resistant creeping bentgrass plants (Agrostis stolonifera L.) without antibiotic-resistant markers were produced by Agrobacterium-mediated transformation. Embryogenic callus tissues were infected with Agrobacterium tumefaciens EHA105, harboring the bar and the CP4-EPSPS genes for bialaphos and glyphosate resistance. Phosphinothricin-resistant calli and plants were selected. Soil-grown plants were obtained at 14-16 weeks after transformation. Genetic transformation of the selected, regenerated plants was validated by PCR. Southern blot analysis revealed that at least one copy of the transgene was integrated into the genome of the transgenic plants. Transgene expression was confirmed by Northern blot. CP4-EPSPS protein was detected by ELISA. Transgenic plants remained green and healthy when sprayed with Basta, containing 0.5% glufosinate ammonium or glyphosate. The optimized Agrobacterium-mediated transformation method resulted in an average of 9.4% transgenic plants. The results of the present study suggest that the optimized marker-free technique could be used as an effective and reliable method for routine transformation, which may facilitate the development of varieties of new antibiotic-free grass species.

  16. Identification of ionic chloroacetanilide-herbicide metabolites in surface water and groundwater by HPLC/MS using negative ion spray

    Science.gov (United States)

    Ferrer, I.; Thurman, E.M.; Barcelo, D.

    1997-01-01

    Solid-phase extraction (SPE) was combined with high-performance liquid chromatography/high-flow pneumatically assisted electrospray mass spectrometry (HPLC/ESP/MS) for the trace analysis of oxanilic and sulfonic acids of acetochlor, alachlor, and metolachlor. The isolation procedure separated the chloroacetanilide metabolites from the parent herbicides during the elution from C18 cartridges using ethyl acetate for parent compounds, followed by methanol for the anionic metabolites. The metabolites were separated chromatographically using reversed-phase HPLC and analyzed by negative-ion MS using electrospray ionization in selected ion mode. Quantitation limits were 0.01 ??g/L for both the oxanilic and sulfonic acids based on a 100-mL water sample. This combination of methods represents an important advance in environmental analysis of chloroacetanilide-herbicide metabolites in surface water and groundwater for two reasons. First, anionic chloroacetanilide metabolites are a major class of degradation products that are readily leached to groundwater in agricultural areas. Second, anionic metabolites, which are not able to be analyzed by conventional methods such as liquid extraction and gas chromatography/mass spectrometry, are effectively analyzed by SPE and high-flow pneumatically assisted electrospray mass spectrometry. This paper reports the first HPLC/MS identification of these metabolites in surface water and groundwater.

  17. Persistence and degradation of the herbicide hexazinone in soils of lowbush blueberry fields in Nova Scotia, Canada

    International Nuclear Information System (INIS)

    Jensen, K.I.N.; Kimball, E.R.

    1987-01-01

    Hexazinone is a broad spectrum herbicide used primarily in forestry, industrial and right-of-way weed control. Hexazinone is very water soluble. It readily leaches in soils and, depending on rainfall and slope, can be transported laterally following surface applications. Eight metabolites were extracted from 14 C-hexazinone treated soils and metabolite C was the major metabolite at each location. Hexazinone is degraded primarily by microorganisms in the soil with little degradation occurring under sterile or anaerobic conditions. The native lowbush blueberry (Vaccinium angustifolium) is tolerant to hexazinone at rates that give selective control of many weedy species associated with this crop. This blueberry is an important fruit crop of Maine and the Eastern Canadian provinces where commercial fields have been developed by management of wild stands originating from forests or abandoned farmland. Hexazinone is now widely used in all blueberry producing areas with thousands of hectares treated annually. The following study examines the fate of this 14 C-labelled herbicide in several typical soil types in the field and under laboratory conditions

  18. Chiral separation of aryloxyphenoxy-propionate herbicides in a permethyl-β-cyclodextrin based column. Influence of temperature and mobile phase composition on enantioselectivity.

    Science.gov (United States)

    Lubomirsky, Ester; Padró, Juan M; Di Loreto, Héctor; Castells, Cecilia B

    2017-08-01

    We used a permethyl-β-cyclodextrin chiral stationary phase under reversed-phase conditions for the chiral separation of four aryloxyphenoxy-propionate herbicides (fenoxaprop-p-ethyl, quizalofop-p-ethyl and tefuryl, and haloxyfop-p-methyl) with mixtures of methanol, ethanol, 2-propanol, n-propanol, tert-butanol, or acetonitrile and water as mobile phases and investigated the influence of mobile phase composition and column temperature (from 0 to 50°C) on the separation. The retention factors (k) and selectivity factors (α) of all the herbicides investigated decreased with increasing temperature. The lnα versus 1/T and lnk versus 1/T plots for the enantiomers of the chiral pesticides were linear within the range of 0-50°C with all alcohol/water mixtures constituting the mobile phase, but the lnk versus 1/T plots were nonlinear for all the enantiomers chromatographed in acetonitrile/water mixtures. The thermodynamic parameters based on linear van't Hoff plots were calculated. The influence of temperature and mobile phase composition on the enantioseparation of the solutes has rarely been considered simultaneously. The temperature and the solvents used in the mobile phase, however, were found to have a profound effect on the enantioseparation of these herbicides. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Diversity of weed communities in soybean [Glycine max (L.] crop growing under direct sowing depending on cover crops and different herbicide doses

    Directory of Open Access Journals (Sweden)

    Elżbieta Harasim

    2016-12-01

    Full Text Available Despite being harmful for agricultural production, weeds are an essential component of biodiversity in agricultural landscapes. A field study was conducted during the period 2007–2009 on grey-brown podzolic soil (sandy, designated as PWsp, with the granulometric composition of silt and classified Class 2 in agricultural land suitability. The study evaluated the structure of weed communities based on selected indicators of diversity of a soybean crop grown under no-tillage with mulch from winter rye, winter oilseed rape, and white mustard as well as using herbicide rates reduced by 25% and 50% in relation to the standard rate (2 L ha−1. The studied factors were as follows: (i mulch plant species and mulch management method; (ii rates of the foliar herbicide Basagran 600 SL (a.i. bentazon; 600 g L−1. The results of this study confirm that no-tillage with mulch significantly changes the diversity of weed flora in a soybean crop. Among the mulches used, the mowed rye and winter oilseed rape in particular increased the values of the general diversity (H', species richness (d, and evenness (J' indices relative to the control treatment. On the other hand, the study found a strong decrease in the value of the dominance index (c. Reduced herbicide rates modified only the species richness index, in the case of which the 75% rate resulted in its significantly higher values compared to the full rate.

  20. Use of isotopic tracers in studies of herbicides performance on grasses and sedges. Report of a final research co-ordination meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    Herbicide products as sold to the user are a mixture or formulation of active ingredient, surfactants and other adjuvants, plus a carrier, which will be a liquid if the formulation is to be applied as a spray. The adjuvants affect the characteristics of the spray, including the retention of the droplets by plant surfaces and the penetration of active ingredient into the plant. Thus they play a critical part in determining the phototoxicity and selectivity of the product. The IAEA organized a co-ordinated research programme in 1992 to explore the possibility of improving the performance of the herbicide glyphosate on Cyperus rotundus (purple nutsedge), commonly regarded as the ``world`s worst weed``, by modifying the commercial formulation using penetration studies with {sup 14}C labelled glyphosate as the initial screening procedure. This TECDOC summarizes the outcome of the programme and includes the papers presented at the research co-ordination meeting held in Los Banos, Philippines, 17-21 February 1997. The co-operation of the Monsanto Company, the manufacturer of the glyphosate herbicide, is gratefully acknowledged. Refs, figs, tabs.

  1. Use of isotopic tracers in studies of herbicides performance on grasses and sedges. Report of a final research co-ordination meeting

    International Nuclear Information System (INIS)

    1998-02-01

    Herbicide products as sold to the user are a mixture or formulation of active ingredient, surfactants and other adjuvants, plus a carrier, which will be a liquid if the formulation is to be applied as a spray. The adjuvants affect the characteristics of the spray, including the retention of the droplets by plant surfaces and the penetration of active ingredient into the plant. Thus they play a critical part in determining the phototoxicity and selectivity of the product. The IAEA organized a co-ordinated research programme in 1992 to explore the possibility of improving the performance of the herbicide glyphosate on Cyperus rotundus (purple nutsedge), commonly regarded as the ''world's worst weed'', by modifying the commercial formulation using penetration studies with 14 C labelled glyphosate as the initial screening procedure. This TECDOC summarizes the outcome of the programme and includes the papers presented at the research co-ordination meeting held in Los Banos, Philippines, 17-21 February 1997. The co-operation of the Monsanto Company, the manufacturer of the glyphosate herbicide, is gratefully acknowledged

  2. Survey of the Current Status of Weed Control and Herbicide Usage by the Small-Scale Commercial Vegetable Farmers in Kenya

    International Nuclear Information System (INIS)

    Mburu, D.N; Drennan, D.S.H

    1999-01-01

    Vegetable production in Kenya is a market that has grown very rapidly in the decade due to increased demand in the local and international markets. This has led to an increase in hectarerage planted to vegetable thus leading in labour shortage due urban migration of potential casual labourers especially the youth. This has resulted to inadequate labour for weed control especially at the critical period. The objectives of this study were to find out the problems encountered by farmers in their bid to control weeds and whether they considered weeds as their major problem. The survey was conducted in Kikuyu, Lari and Kinango divisions where intensive vegetable farming is done by small-scale farmers for commercial purposes. The farmers were randomly selected and interviews conducted in their farms, based on Participatory Rural Appraisal (PRA) method. The results obtained showed that the farmers who previously relied on manual labour for weed control were increasingly using herbicides for weed control. The adoption of herbicide technology by these small scale farmers was out of their own initiative, either due to labour shortage or because one had a special weed problem that had defied other methods of control.From the information obtained it was clear that locally generated data information on herbicide use by small-scale farmers is seriously lacking for most if not all vegetable crops

  3. A further evaluation of herbicides for post-emergence use in short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, D.J.

    2002-07-01

    This report summarises the findings of a project evaluating the safety and efficiency of eleven herbicides for controlling weeds in newly plated willow short rotation coppices, and provides growers with information on post-emergence herbicide options, control of problem weeds, and emergency treatments. Weed germination, crop safety, and the encouraging results obtained using Reflex T and Impuls are discussed. It is suggested that a Technical Register of herbicide applications with contributions by growers and advisers should be considered by the British Biogen trade industry body.

  4. Glufosinate herbicide intoxication causing unconsciousness, convulsion, and 6th cranial nerve palsy.

    Science.gov (United States)

    Park, Jae-seok; Kwak, Soo-Jung; Gil, Hyo-wook; Kim, So-Young; Hong, Sae-yong

    2013-11-01

    Although glufosinate ammonium herbicides are considered safe when used properly, ingestion of the undiluted form can cause grave outcomes. Recently, we treated a 34-yr-old man who ingested glufosinate ammonium herbicide. In the course of treatment, the patient developed apnea, mental deterioration, and sixth cranial nerve palsy; he has since been discharged with full recovery after intensive care. This case report describes the clinical features of glufosinate intoxication with a focus on sixth cranial nerve palsy. Our observation suggests that neurologic manifestations after ingestion of a "low-grade toxicity herbicide" are variable and more complex than that was previously considered.

  5. Ecological review of black-grass (Alopecurus myosuroides Huds. propagation abilities in relationship with herbicide resistance

    Directory of Open Access Journals (Sweden)

    Maréchal, PY.

    2012-01-01

    Full Text Available Alopecurus myosuroides Huds. (black-grass has always been a major concern for cereal growers, and the development of herbicide resistance does not improve the situation. This review article summarizes the different traits involved in the dispersal pattern of herbicide resistant black-grass individuals within a susceptible field population. Therefore, the whole life cycle of black-grass is depicted from the seed to the seed. From the early vegetative development to the seed falling, every stage is described, taking into account how herbicide resistance can influence or exert a different impact compared to susceptible plants.

  6. An evaluation of herbicides for post-emergence use in short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, D.J.

    2000-07-01

    The objective of the project was to evaluate the safety and efficacy of a range of herbicides and mixtures of herbicides, with both contact and residual activity, for the post-emergence control of weeds in newly planted willow short rotation coppice (SRC). This report provides growers and advisers of short rotation coppice with important (but still limited) information on how to achieve improved weed control of problem weeds increasingly prevalent in SRC fields. This may provide guidance towards often-essential emergency treatments when the crop establishment is under considerable pressure and the potential safety, or otherwise, of certain weed-specific herbicides. (author)

  7. Production of herbicide-resistant coffee plants (Coffea canephora P. via Agrobacterium tumefaciens-mediated transformation

    Directory of Open Access Journals (Sweden)

    Alessandra Ferreira Ribas

    2006-01-01

    Full Text Available Transgenic plants of Coffea canephora P. resistant to the herbicide ammonium glufosinate were regenerated from leaf explants after co-culture with Agrobacterium tumefaciens strain EHA105 harboring pCambia3301, a plasmid that contains the bar and the uidA genes both under control of 35S promoter. Direct somatic embryogenesis was induced on basal medium contained ¼ strength macro salts and half strength micro salts of MS medium, organic constituents of B5 medium and 30 g.L-1 sucrose supplemented with 5µM N6 - (2-isopentenyl-adenine (2-iP. Ten µM ammonium glufosinate was used for putative transgenic somatic embryos selection. Presence and integration of the bar gene were confirmed by PCR and Southern blot analysis. Selected transgenic coffee plants sprayed with up to 1600 mg.L-1 of FinaleTM, a herbicide containing glufosinate as the active ingredient, retained their pigmentation and continued to grow normally during ex vitro acclimation.Plantas transgênicas de Coffea canephora P resistentes ao herbicida glufosinato de amônio foram regeneradas a partir de explantes foliares co-cultivados com Agrobacterium tumefaciens EHA105 contendo o plasmídio pCambia3301 que contém os genes bar e uidA ambos sob controle do promotor 35S. Embriogênese somática direta foi induzida no meio contendo ¼ da concentração de macro, metade da concentração de micronutrientes do meio MS, constituintes orgânicos do meio B5 e 30 g.L-1 de sacarose suplementado com 5µM N6 - (2-isopentenil-adenina (2-iP e 10 µM de glufosinato de amônio para seleção de embriões transgênicos putativos. A presença e a integração do gene bar foram confirmados pelas análises de PCR e Southern blot. As plantas transgênicas selecionadas de café, pulverizadas com 1600 mg.L-1 do herbicida FinaleTM que contém glufosinato como ingrediente ativo, mantiveram a coloração e continuaram crescendo normalmente na aclimatação ex vitro.

  8. Fungal phytotoxins with potential herbicidal activity: chemical and biological characterization.

    Science.gov (United States)

    Cimmino, Alessio; Masi, Marco; Evidente, Marco; Superchi, Stefano; Evidente, Antonio

    2015-12-19

    Covering: 2007 to 2015 Fungal phytotoxins are secondary metabolites playing an important role in the induction of disease symptoms interfering with host plant physiological processes. Although fungal pathogens represent a heavy constraint for agrarian production and for forest and environmental heritage, they can also represent an ecofriendly alternative to manage weeds. Indeed, the phytotoxins produced by weed pathogenic fungi are an efficient tool to design natural, safe bioherbicides. Their use could avoid that of synthetic pesticides causing resistance in the host plants and the long term impact of residues in agricultural products with a risk to human and animal health. The isolation and structural and biological characterization of phytotoxins produced by pathogenic fungi for weeds, including parasitic plants, are described. Structure activity relationships and mode of action studies for some phytotoxins are also reported to elucidate the herbicide potential of these promising fungal metabolites.

  9. [Poisonings with the herbicides glyphosate and glyphosate-trimesium].

    Science.gov (United States)

    Mortensen, O S; Sørensen, F W; Gregersen, M; Jensen, K

    2000-08-28

    Generally the herbicide glyphosate is considered harmless to humans. Glyphosate-trimesium is labelled harmful (Xn), whereas glyphosate-isopropylamine carries no warning sign. As cases of serious poisoning have emerged contacts to the Poison Information Centre have been reviewed. The persons exposed were mainly smaller children and adults 20 to 59 years of age. Oral exposure was recorded in 47 persons, inhalation exposure in 24 and topical contact in 42. About one fourth of the exposed persons were asymptomatic. Most of the symptomatic poisonings demonstrated complaints from the mouth, the gastrointestinal tract and the airways. Eleven patients were admitted to hospital. Two died, one of them having ingested the isopropylamine salt, the other the trimesium salt. Death ensued quickly in the latter patient. A similar fate was observed in a child--not included in the present material--who had also ingested the trimesium compound.

  10. Quito's Urban Watersheds: Applications of Low Impact Development and Sustainable Watershed Management

    Science.gov (United States)

    Marzion, R.; Serra-Llobet, A.; Ward Simons, C.; Kondolf, G. M.

    2013-12-01

    Quito, Ecuador sits high in an Interandean valley (elevation ~2,830 meters) at the foot of Pichincha volcano. Above the city, mountain streams descend from high-altitude Andean páramo grasslands down steep slopes through quebradas (ravines) to the Machángara River. Quito's rapid urban growth, while indicative of the city's economic vitality, has led to the city's expansion along the valley floor, settlements along precarious hillslopes and ravines, disappearance of wetlands, and loss of páramo. The upper reaches of the watersheds are being rapidly settled by migrants whose land-use practices result in contamination of waters. In the densely-settled downstream reaches, urban encroachment has resulted in filling and narrowing of quebradas with garbage and other poor-quality fill. These practices have dramatically altered natural drainage patterns, reduced the flood conveyance capacity of the channels (increasing the flood risk to surrounding communities), and further deteriorated water quality. The city's stormwater, wastewater, and surface waters suffer from untreated pollutant loads, aging pipes, and sewer overflows. In response to environmental degradation of the quebradas, awareness is increasing, at both local community and municipal levels, of the importance of stream corridors for water quality, wildlife, and recreation for nearby residents. Citizen groups have organized volunteer river cleanups, and municipal agencies have committed to implementing ';green infrastructure' solutions to make Quito a healthier habitat for humans and other species. City leaders are evaluating innovative low impact development (LID) methods to help decontaminate surface waters, mitigate urban flooding, and promote sustainable water systems. Quito's municipal water agency, EPMAPS, invited faculty and students from Quito and Berkeley to collaborate with agency staff and citizen groups to analyze opportunities and to develop plans and designs for sustainable infrastructure. To

  11. Glufosinate (phosphinothricin), a natural amino acid with unexpected herbicidal properties.

    Science.gov (United States)

    Hoerlein, G

    1994-01-01

    Glufosinate ammonium (phosphinothricin ammonium) (GLA) is the active ingredient of Basta and several other herbicides used worldwide. It is produced as part of the tripeptide L-phosphinothricyl-L-alanyl-L-alanin, which was first isolated from Streptomyces viridichromogenes or Streptomyces hygroscopicus. Its structure is confirmed by degradation and synthesis. Several processes for the preparation of D,L- and L-phosphinothricin are described. Glufosinate is a structural analog of glutamate and inhibits the glutamine synthetase. The result is a rapid build-up of a high ammonia level and a concomitant depletion of glutamine and several other amino acids in the plant. These effects are accompanied by a rapid decline of photosynthetic CO2-fixation and are followed by chlorosis and desiccation. The results of numerous toxicological studies show that glufosinate ammonium and its commercial formulations are safe for users and consumers under the conditions of recommended use. The fast and complete degradation in soil and surface water prevents movement of residues into groundwater. The toxicological threshold levels for all the nontarget organisms tested are well above the potential exposure levels and therefore do not reflect any hazard for nontarget organisms in the ecosystem. Basta is a nonselective foliar applied herbicide for the control of undesirable mono- and dicotyledonous plants in orchards, vineyards, and plantations for minimum tillage, and as a harvest aid. A synthetic phosphinothricin acetyltransferase (PAT) gene has been introduced via Agrobacterium tumefaciens into dicot crops, such as like tobacco, tomato, spring and winter rapeseed, alfalfa, and several horticultural crops. The PAT gene was also successfully introduced into maize protoplasts that could be regenerated into fertile plants. All transgenic crop plants tolerated a two- to threefold field dosage of Basta.

  12. Differential Growth Responses of Marine Phytoplankton to Herbicide Glyphosate.

    Directory of Open Access Journals (Sweden)

    Cong Wang

    Full Text Available Glyphosate is a globally popular herbicide to kill weeds and its wide applications may lead to accumulation in coastal oceans as a source of phosphorus (P nutrient or growth inhibitor of phytoplankton. We studied the physiological effects of glyphosate on fourteen species representing five major coastal phytoplankton phyla (haptophyta, bacillariophyta, dinoflagellata, raphidophyta, and chlorophyta. Based on growth responses to different concentrations of glyphosate under contrasting dissolved inorganic phosphorus (DIP conditions, we found that phytoplankton species could be classified into five groups. Group I (Emiliania huxleyi, Skeletonema costatum, Phaeodactylum tricornutum could utilize glyphosate as sole P-source to support growth in axenic culture, but in the presence of DIP, they were inhibited by both 36-μM and 360-μM glyphosate. Group II (Karenia mikimotoi, Prorocentrum minimum, Dunaliella tertiolecta, Symbiodinium sp., Heterosigma akashiwo and Alexandrium catenella could not utilize glyphosate as sole P-source to support growth, and in the presence of DIP growth was not affected by 36-μM but inhibited by 360-μM glyphosate. Glyphosate consistently enhanced growth of Group III (Isochrysis galbana and inhibited Group IV (Thalassiosira weissflogii, Thalassiosira pseudonana and Chattonella marina regardless of DIP condition. Group V (Amphidinium carterae exhibited no measurable response to glyphosate regardless of DIP condition. This grouping is not congruent with the phylogenetic relationships of the phytoplankton species suggesting functional differentiation driven by environmental pressure. We conclude that glyphosate could be used as P-source by some species while is toxic to some other species and yet has no effects on others. The observed differential effects suggest that the continued use of glyphosate and increasing concentration of this herbicide in the coastal waters will likely exert significant impact on coastal marine

  13. Differential Growth Responses of Marine Phytoplankton to Herbicide Glyphosate

    Science.gov (United States)

    Wang, Cong; Lin, Xin; Li, Ling; Lin, Senjie

    2016-01-01

    Glyphosate is a globally popular herbicide to kill weeds and its wide applications may lead to accumulation in coastal oceans as a source of phosphorus (P) nutrient or growth inhibitor of phytoplankton. We studied the physiological effects of glyphosate on fourteen species representing five major coastal phytoplankton phyla (haptophyta, bacillariophyta, dinoflagellata, raphidophyta, and chlorophyta). Based on growth responses to different concentrations of glyphosate under contrasting dissolved inorganic phosphorus (DIP) conditions, we found that phytoplankton species could be classified into five groups. Group I (Emiliania huxleyi, Skeletonema costatum, Phaeodactylum tricornutum) could utilize glyphosate as sole P-source to support growth in axenic culture, but in the presence of DIP, they were inhibited by both 36-μM and 360-μM glyphosate. Group II (Karenia mikimotoi, Prorocentrum minimum, Dunaliella tertiolecta, Symbiodinium sp., Heterosigma akashiwo and Alexandrium catenella) could not utilize glyphosate as sole P-source to support growth, and in the presence of DIP growth was not affected by 36-μM but inhibited by 360-μM glyphosate. Glyphosate consistently enhanced growth of Group III (Isochrysis galbana) and inhibited Group IV (Thalassiosira weissflogii, Thalassiosira pseudonana and Chattonella marina) regardless of DIP condition. Group V (Amphidinium carterae) exhibited no measurable response to glyphosate regardless of DIP condition. This grouping is not congruent with the phylogenetic relationships of the phytoplankton species suggesting functional differentiation driven by environmental pressure. We conclude that glyphosate could be used as P-source by some species while is toxic to some other species and yet has no effects on others. The observed differential effects suggest that the continued use of glyphosate and increasing concentration of this herbicide in the coastal waters will likely exert significant impact on coastal marine phytoplankton

  14. Antifouling herbicides in the coastal waters of western Japan.

    Science.gov (United States)

    Okamura, H; Aoyama, I; Ono, Y; Nishida, T

    2003-01-01

    Residue analyses of some antifouling herbicides (Diuron, Irgarol 1051 and the latter's degradation product M1, which is also known as GS26575), were conducted in waters collected along the coast of western Japan. In total, 142 water samples were collected from fishery harbours (99 sites), marinas (27 sites), and small ports (16 sites) around the Seto Inland Sea, the Kii Peninsula, and Lake Biwa, in August 1999. A urea-based herbicide, Diuron, was positively identified for the first time in Japanese aquatic environments. Diuron was detected in 121 samples (86%) up to a highest concentration of 3.05 microg/l, and was found in 86% of samples from fishery harbours, 89% from marinas, and 75% from ports. Four freshwater samples out of 11 collected at Lake Biwa contained Diuron. Neither Irgarol 1051 nor M1 was found in the lake waters, but both were found in many coastal waters. Irgarol 1051 was found in 84 samples (60%) at a highest concentration of 0.262 microg/l. The concentrations detected were of similar magnitude to those in our previous surveys, taken in 1997 and 1998. M1 was found in 40 samples (28%) up to a highest concentration of 0.080 microg/l. The concentrations detected were generally lower than those found in our previous surveys. The detection frequency among fishery harbours, marinas, and ports was 57-70% for Irgarol 1051 and 25-30% for M1. Ninety-five per cent of the coastal waters in which M1 was detected also contained Irgarol 1051, and 93% of the samples in which Irgarol 1051 was detected also contained Diuron. These results clearly suggest that commercial ship-bottom paints containing both Diuron and Irgarol 1051 are used extensively in the survey area.

  15. Triazine herbicides inhibit relaxin signaling and disrupt nitric oxide homeostasis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Si Eun; Lim, Sa Rang; Choi, Hyung-kyoon; Bae, Jeehyeon, E-mail: jeehyeon@cau.ac.kr

    2016-09-15

    Triazines are herbicides that are widely used worldwide, and we previously observed that the maternal exposure of mice to simazine (50 or 500 μg/kg) resulted in smaller ovaries and uteri of their female offspring. Here, we investigated the underlying mechanism that may account for the reproductive dysfunction induced by simazine. We found that following maternal exposure, simazine is transmitted to the offspring, as evidenced by its presence in the offspring ovaries. Analyses of the simazine-exposed offspring revealed that the expression of the relaxin hormone receptor, relaxin-family peptide receptor 1 (RXFP1), prominently decreased in their ovaries and uteri. In addition, downstream target genes of the relaxin pathway including nitric oxide (NO) synthase 2 (Nos2), Nos3, matrix metallopeptidase 9 (Mmp9), and vascular endothelial growth factor (Vegf) were downregulated in their ovaries. Moreover, AKT and extracellular signal-regulated kinases (ERK) levels and their phosphorylated active forms decreased in simazine-exposed ovaries. In vitro exposure of the human ovarian granulosa cells (KGN) and uterine endometrium cells (Hec-1A) to very low concentrations (0.001 to 1 nM) of triazines including atrazine, terbuthylazine, and propazine repressed NO production with a concurrent reduction in RXFP1, NOS2, and NOS3. The inhibitory action of triazines on NO release was dependent on RXFP1, phosphoinositol 3-kinase (PI3K)/AKT, and ERK. Radioligand-binding assay also confirmed that triazines competitively inhibited the binding of relaxin to its receptor. Therefore, the present study suggests that triazine herbicides act as endocrine disrupters by interfering with relaxin hormone signaling. Thus, further evaluation of their impact on human health is imperative. - Highlights: • Triazines downregulate critical molecules involved in the relaxin signaling pathway. • Triazines act as potent antagonists of binding of relaxin to its receptor. • Triazines disrupt nitric oxide

  16. Glyphosate em mistura com herbicidas alternativos para o manejo de plantas daninhas Glyphosate combined with alternative herbicides for vegetation management

    Directory of Open Access Journals (Sweden)

    P.A. Monquero

    2001-12-01

    Full Text Available O uso intensivo de glyphosate como herbicida não-seletivo tem selecionado espécies de plantas daninhas tolerantes. Dessa forma, é importante que sejam estudadas misturas de tanque com herbicidas de mecanismos de ação alternativos e que apresentem efeitos sinergísticos ou aditivos. Por essa razão, foi instalado um experimento inteiramente casualizado, composto por 13 tratamentos e 4 repetições, em casa de vegetação da Universidade de São Paulo - ESALQ/USP, Piracicaba-SP, com as plantas daninhas Richardia brasiliensis, Commelina benghalensis, Amaranthus hybridus, Galinsoga parviflora e Ipomoea grandifolia em misturas de tanque dos herbicidas chlorimuron-ethyl, sulfentrazone, carfentrazone, bentazon ou flumioxazin com glyphosate. As interações foram aditivas para as plantas daninhas I. grandifolia e C. benghalensis, e os herbicidas flumioxazin, sulfentrazone e carfentrazone aplicados isoladamente e em mistura com glyphosate foram os que proporcionaram os melhores níveis de controle. A interação de glyphosate com sulfentrazone foi antagônica em R. brasiliensis; a mistura de glyphosate com os demais herbicidas estudados foi aditiva, sendo os tratamentos com mistura de glyphosate e chlorimuron-ethyl ou flumioxazin os mais eficazes. Em A. hybridus, os tratamentos que apresentaram melhores níveis de controle foram o glyphosate e carfentrazone, aplicados isoladamente, e a mistura de glyphosate com flumioxazin, sulfentrazone, chlorimuron-ethyl e bentazon, sendo estes interações aditivas. No caso de G. parviflora, os tratamentos com flumioxazin e sulfentrazone apresentaram controle total, o mesmo acontecendo com as misturas de glyphosate com carfentrazone, flumioxazin, sulfentrazone, chlorimuron-ethyl ou bentazon.The intensive use of glyphosate as a non-selective herbicide for weed vegetation management has selected some tolerant weed species. Thus, it is important to study the synergistic or antagonic or additive effects of tank

  17. The direct and indirect effects of a glyphosate-based herbicide and nutrients on Chironomidae (Diptera) emerging from small wetlands.

    Science.gov (United States)

    Baker, Leanne F; Mudge, Joseph F; Houlahan, Jeff E; Thompson, Dean G; Kidd, Karen A

    2014-09-01

    Laboratory and mesocosm experiments have demonstrated that some glyphosate-based herbicides can have negative effects on benthic invertebrate species. Although these herbicides are among the most widely used in agriculture, there have been few multiple-stressor, natural system-based investigations of the impacts of glyphosate-based herbicides in combination with fertilizers on the emergence patterns of chironomids from wetlands. Using a replicated, split-wetland experiment, the authors examined the effects of 2 nominal concentrations (2.88 mg acid equivalents/L and 0.21 mg acid equivalents/L) of the glyphosate herbicide Roundup WeatherMax, alone or in combination with nutrient additions, on the emergence of Chironomidae (Diptera) before and after herbicide-induced damage to macrophytes. There were no direct effects of treatment on the structure of the Chironomidae community or on the overall emergence rates. However, after macrophyte cover declined as a result of herbicide application, there were statistically significant increases in emergence in all but the highest herbicide treatment, which had also received no nutrients. There was a negative relationship between chironomid abundance and macrophyte cover on the treated sides of wetlands. Fertilizer application did not appear to compound the effects of the herbicide treatments. Although direct toxicity of Roundup WeatherMax was not apparent, the authors observed longer-term impacts, suggesting that the indirect effects of this herbicide deserve more consideration when assessing the ecological risk of using herbicides in proximity to wetlands. © 2014 SETAC.

  18. Leaching of the S-metolachlor herbicide associated with paraquat or glyphosate in a no-tillage system

    Directory of Open Access Journals (Sweden)

    Anderson Luis Nunes

    2016-09-01

    Full Text Available The combined use of desiccant and residual herbicides is a common management practice under no-tillage systems. However, the effect of desiccant herbicides and mulch on the leaching of residual herbicide is unknown. This study aimed at assessing the leaching of the S-metolachlor herbicide applied to ryegrass sequentially or in association with paraquat or glyphosate. A randomized blocks design was used, with four repetitions and treatments distributed over split-plots. The desiccant herbicides paraquat (600 g ha-1 or glyphosate (720 g ha-1 were used in the main plot, while S-metolachlor (2,800 g ha-1 was applied sequentially or in association with the desiccant herbicides in the subplots. There was also a control containing only desiccant herbicide, with no application of residual herbicide. The type of desiccant did not affect the leaching of the residual herbicide. In addition, the chosen method to apply the residual herbicide, sequentially or in association with the desiccant, did not impact the S-metolachlor behavior in the soil. The bioavailable concentration in the soil, 25 days after the application, was 90 g a.i. ha-1, at a depth of 18 cm.

  19. Alternatives to herbicides in an apple orchard, effects on yield, earthworms and plant diversity

    DEFF Research Database (Denmark)

    Andersen, L.; Kuehn, Birka Falk; Bertelsen, M.

    2013-01-01

    tIn a newly established apple orchard eight alternative methods to weed control in the tree row werecompared to a herbicide treatment with respect to effects on tree growth, first-quality fruit yield, earth-worms and flora. All treatments were tested at two irrigation schedules, with similar amount......, whereasmulching with paper wool reduced first-quality fruit yield compared to herbicide treatment. Cover cropas tagetes and weed harrowing had similar yield as herbicide treatment, whereas cover crops as grassand hop medick and weed cutting reduced first-quality yield compared to herbicide treatment. Earth......-worms thrived under rape straw contrary to under black polypropylene and plots with weed harrowing.Treatments had significant effects on species numbers of plants both years, and total vegetation covergenerally increased in the second year. Rape straw supported a high production of apples and a largestock...

  20. CHRONIC EFFECTS OF THE HERBICIDE DIURON ON FRESHWATER CLADOCERANS,AMPHIPODS,MIDGES,MINNOWS,WORMS, AND SNAILS

    Science.gov (United States)

    The chronic effects of the herbicide diuron on survival and reproduction of Daphnia pulex, and survival and growth of the amphipod Hyalella azteca, the midge Chironomus tentans, juvenile and embro/larval fathead minnows, Pimephales promelas, annelid worms, Lumbriculus variegatus,...

  1. Arabidopsis transcriptional responses differentiating closely related chemicals (herbicides) and cross-species extrapolation to Brassica

    Science.gov (United States)

    Using whole genome Affymetrix ATH1 GeneChips we characterized the transcriptional response of Arabidopsis thaliana Columbia 24 hours after treatment with five different herbicides. Four of them (chloransulam, imazapyr, primisulfuron, sulfometuron) inhibit acetolactate synthase (A...

  2. Microevolution of ALS inhibitor herbicide resistance in loose silky bentgrass (Apera spica-venti)

    DEFF Research Database (Denmark)

    Babineau, Marielle

    , the ALS resistant biotypes have a fitness advantage over the susceptible biotype in time to germination and time to flowering and seed production growth stages. This study increased the understanding of the spatial, phenotypic, genetic and ecological processes and consequences in ALS herbicide resistance......-neighborhood experiments were conducted with ALS resistant and susceptible populations with a randomized genetic background, vegetative and reproductive growth stages were compared. The results show a large variation in the response of neighboring populations to ALS herbicide. Multiple resistance is observed between ALS...... from known metabolic herbicide resistance pathways, such as cytochrome P450s, ABC-transporters, UDP-glycosyltransferase and glutathione S-transferase, are identified and quantified. Different gene families are up-regulated at different times after herbicide treatment. In low competition conditions...

  3. Crops with target-site herbicide resistance for Orobanche and Striga control.

    Science.gov (United States)

    Gressel, Jonathan

    2009-05-01

    It is necessary to control root parasitic weeds before or as they attach to the crop. This can only be easily achieved chemically with herbicides that are systemic, or with herbicides that are active in soil. Long-term control can only be attained if the crops do not metabolise the herbicide, i.e. have target-site resistance. Such target-site resistances have allowed foliar applications of herbicides inhibiting enol-pyruvylshikimate phosphate synthase (EPSPS) (glyphosate), acetolactate synthase (ALS) (e.g. chlorsulfuron, imazapyr) and dihydropteroate synthase (asulam) for Orobanche control in experimental conditions with various crops. Large-scale use of imazapyr as a seed dressing of imidazolinone-resistant maize has been commercialised for Striga control. Crops with two target-site resistances will be more resilient to the evolution of resistance in the parasite, if well managed.

  4. ANALYTICAL METHOD DEVELOPMENT FOR ALACHLOR ESA AND OTHER ACETANILIDE HERBICIDE DEGRADATION PRODUCTS

    Science.gov (United States)

    In 1998, USEPA published a Drinking Water Contaminant Candidate List (CCL) of 50 chemicals and 10 microorganisms. "Alachlor ESA and other acetanilide herbicide degradation products" is listed on the the 1998 CCL. Acetanilide degradation products are generally more water soluble...

  5. Responses of reniform nematode and browntop millet to tillage, cover crop, and herbicides in cotton

    Science.gov (United States)

    Cropping practices that reduce competition from reniform nematode (Rotylenchulus reniformis) and browntop millet (Urochlora ramosum) may help minimize losses in cotton (Gossypium hirsutum). The impacts of tillage, rye cover crop, and preemergence and postemergence herbicides on cotton yields, renifo...

  6. CYTOGENETIC STUDIES OF THREE TRIAZINE HERBICIDES II. IN VIVO MICRONUCLEUS STUDIES IN MOUSE BONE MARROW

    Science.gov (United States)

    Atrazine, simazine, and cyanazine are widely used preemergence and postemergence triazine herbicides that have made their way into the potable water supply of many agricultural communities. There are several contradictory studies in the literature. Our previous in vitro studies...

  7. Evaluation the Effect of Corn (Zea mays L. Sowing Pattern and Nitrogen Application Method on Herbicide Optimizing and Reducing Foramsulfuron (Equip® Dose

    Directory of Open Access Journals (Sweden)

    E. Izadi Darbandi

    2016-06-01

    Full Text Available Introduction: In the whole agro ecosystems, weeds had existence as unwanted plant that control of them is necessary. The competition between weeds and corn for moisture, light, nutrients during the growth season is induced reducing the quality and quantity of corn yield. Although the corn is high and powerful crop but is sensitive to competition with the weed and reduction of yield has been reported over 30%. Since the weeds are adapted to conditions, they are successful to completion and reducing the yield. So weed management is important in corn production. Chemical control has not been the unique and best way to manage the weeds and it reduce the sustainability of agro ecosystems. Although developing the herbicides, reduce the pressures caused by the weeds, but by developing rapidly the weed resistance to herbicides and increasing the environmental concerns and its high cost, today need to new, more immune and sustainable techniques for weed management. The main approach for sustainable weed management in an integrated weed management program is increasing crop competitiveness with weeds to reduce herbicide use. In this regard, the planting date, crop rotation, planting density, intercropping, planting pattern, fertilizer type, rate and application method are some of the most crop management strategies. Among the nutrients necessary for plants, nitrogen is the most nutrient in plant competition. Therefore, its application management plays a key role in reducing weed interference with crops and reduced herbicide use. Foramsulfuron herbicide from ALS inhibitors is a post-emergence sulfonylurea herbicide for the control of grasses and certain broadleaf weeds in maize. Unfortunately, these herbicides are also notorious for their ability to select resistant weed populations. Now, there are more weed species that are resistant to ALS-inhibiting herbicides than to any other herbicide group. In several cropping systems, ALS-inhibiting herbicides were

  8. Photostabilization of the herbicide norflurazon microencapsulated with ethylcellulose in the soil-water system

    Energy Technology Data Exchange (ETDEWEB)

    Sopena, Fatima, E-mail: fsopenav@irnase.csic.es [Institute of Natural Resources and Agrobiology (CSIC), Reina Mercedes 10, Apdo 1052, 41080 Seville, ES (Spain); Villaverde, Jaime; Maqueda, Celia; Morillo, Esmeralda [Institute of Natural Resources and Agrobiology (CSIC), Reina Mercedes 10, Apdo 1052, 41080 Seville, ES (Spain)

    2011-11-15

    Highlights: {yields} Herbicide photodegradation studies using ethylcellulose-microencapsulated formulations (ECF) in soil and water. {yields} Greater herbicide photo-protection observed from EFC than from its commercial form. {yields} Photo-protective effect due to the gradual herbicide release and the presence of ethylcellulose. {yields} Herbicide photo-stability conditioned by soil colloidal components, especially by goethite and humic acids. {yields} EFC could reduce the field herbicide losses by photolysis. - Abstract: Ethylcellulose-microencapsulated formulations (ECFs) of norflurazon have been shown to reduce leaching, maintaining a threshold concentration in the topsoil than the commercial formulation (CF). Since photodegradation contributes to field dissipation of norflurazon, the objective of the present work was to study if such formulations can also protect from its photodescomposition. For this purpose, aqueous solutions of CF and ECFs, containing the most important soil components (goethite, humic and fulvic acids and montmorillonite) were tested. To get a more realistic approach, studies in soil were also performed. The results were well explained by a simple first order model. DT{sub 50} value was 3 h for CF under irradiation, which was considerably lower than those corresponding to the systems where ECF was used (35 h for ECF; 260 h for ECF-goethite; 53 h for ECF-humic acids; 33 h for ECF-montmorillonite; and 28 h for ECF-fulvic acids). ECF protected against photodegradation in both aqueous solution and soil due to the gradual release of the herbicide, which reduced the herbicide available to be photodegraded. These lab-scale findings proved that ECF could reduce the herbicide dosage, minimizing its photolysis, which would be especially advantageous during the first hours after foliar and soil application.

  9. An identification of potential new herbicides for short rotation coppice (Task 4). Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This report summarises the findings of a project to identify potential new herbicides and their suitability for weed control in commercial short rotation coppice (SRC) crops, and to establish the safety of the crops. The arrangements for the use of 'off-label' pesticides, which are permitted for use on other crops, on SRC are discussed along with the importance of the use of laboratory pot trials and field trials. Several herbicides are proposed for larger scale field trials.

  10. Glufosinate Herbicide Intoxication Causing Unconsciousness, Convulsion, and 6th Cranial Nerve Palsy

    OpenAIRE

    Park, Jae-seok; Kwak, Soo-Jung; Gil, Hyo-wook; Kim, So-Young; Hong, Sae-yong

    2013-01-01

    Although glufosinate ammonium herbicides are considered safe when used properly, ingestion of the undiluted form can cause grave outcomes. Recently, we treated a 34-yr-old man who ingested glufosinate ammonium herbicide. In the course of treatment, the patient developed apnea, mental deterioration, and sixth cranial nerve palsy; he has since been discharged with full recovery after intensive care. This case report describes the clinical features of glufosinate intoxication with a focus on six...

  11. Impact of Grassland Reseeding, Herbicide spraying and Ploughing on Diversity and Abundance of Soil Arthropods.

    OpenAIRE

    Wei Liu; Wei Liu; Wei Liu; Junling Zhang; Stuart L Norris; Phil Murray

    2016-01-01

    In order to determine the interactive effect of reseeding, herbicide spraying and ploughing on soil fauna communities, we conducted a grassland reseeding experiment combined with pre-reseed management to examine how with the whole reseeding process affects soil faunal composition. Sampling occasions and exact treatments were as follows: 1) before chemical herbicide spray; 2) after spray but before ploughing; 3) after ploughing but before reseeding; and 4) after one year of recovery. Our resul...

  12. Identification and ecotoxicity of degradation products of chloroacetamide herbicides from UV-treatment of water

    DEFF Research Database (Denmark)

    Souissi, Yasmine; Bouchonnet, Stéphane; Bourcier, Sophie

    2013-01-01

    The widespread occurrence of chlorinated herbicides and their degradation products in the aquatic environment raises health and environmental concerns. As a consequence pesticides, and to a lesser degree their degradation products, are monitored by authorities both in surface waters and drinking...... waters. In this study the formation of degradation products from ultraviolet (UV) treatment of the three chloroacetamide herbicides acetochlor, alachlor and metolachlor and their biological effects were investigated. UV treatment is mainly used for disinfection in water and wastewater treatments. First...

  13. Dinitroaniline herbicide resistance in a multiple-resistant Lolium rigidum population.

    Science.gov (United States)

    Chen, Jinyi; Yu, Qin; Owen, Mechelle; Han, Heping; Powles, Stephen

    2018-04-01

    The pre-emergence dinitroaniline herbicides (such as trifluralin and pendimethalin) are vital to Australian no-till farming systems. A Lolium rigidum population collected from the Western Australian grain belt with a 12-year trifluralin use history was characterised for resistance to dinitroaniline, acetyl CoA carboxylase (ACCase)- and acetolactate synthase (ALS)-inhibiting herbicides. Target-site resistance mechanisms were investigated. This L. rigidum population exhibited 32-fold resistance to trifluralin, as compared with the susceptible population. It also displayed 12- to 30-fold cross-resistance to other dinitroaniline herbicides (pendimethalin, ethalfluralin and oryzalin). In addition, this population showed multiple resistance to commonly used post-emergence ACCase- and ALS-inhibiting herbicides. Two target-site α-tubulin gene mutations (Val-202-Phe and Thr-239-Ile) previously documented in other dinitroaniline-resistant weed species were identified, and some known target-site mutations in ACCase (Ile-1781-Leu, Asp-2078-Gly and Cys-2088-Arg) and ALS (Pro-197-Gln/Ser) were found in the same population. An agar-based Petri dish screening method was established for the rapid diagnosis of resistance to dinitroaniline herbicides. Evolution of target-site resistance to both pre- and post-emergence herbicides was confirmed in a single L. rigidum population. The α-tubulin mutations Val-202-Phe and Thr-239-Ile, documented here for the first time in L. rigidum, are likely to be responsible for dinitroaniline resistance in this population. Early detection of dinitroaniline herbicide resistance and integrated weed management strategies are needed to maintain the effectiveness of dinitroaniline herbicides. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Perspectives on transgenic, herbicide-resistant crops in the United States almost 20 years after introduction.

    Science.gov (United States)

    Duke, Stephen O

    2015-05-01

    Herbicide-resistant crops have had a profound impact on weed management. Most of the impact has been by glyphosate-resistant maize, cotton, soybean and canola. Significant economic savings, yield increases and more efficacious and simplified weed management have resulted in widespread adoption of the technology. Initially, glyphosate-resistant crops enabled significantly reduced tillage and reduced the environmental impact of weed management. Continuous use of glyphosate with glyphosate-resistant crops over broad areas facilitated the evolution of glyphosate-resistant weeds, which have resulted in increases in the use of tillage and other herbicides with glyphosate, reducing some of the initial environmental benefits of glyphosate-resistant crops. Transgenic crops with resistance to auxinic herbicides, as well as to herbicides that inhibit acetolactate synthase, acetyl-CoA carboxylase and hydroxyphenylpyruvate dioxygenase, stacked with glyphosate and/or glufosinate resistance, will become available in the next few years. These technologies will provide additional weed management options for farmers, but will not have all of the positive effects (reduced cost, simplified weed management, lowered environmental impact and reduced tillage) that glyphosate-resistant crops had initially. In the more distant future, other herbicide-resistant crops (including non-transgenic ones), herbicides with new modes of action and technologies that are currently in their infancy (e.g. bioherbicides, sprayable herbicidal RNAi and/or robotic weeding) may affect the role of transgenic, herbicide-resistant crops in weed management. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  15. Photostabilization of the herbicide norflurazon microencapsulated with ethylcellulose in the soil-water system

    International Nuclear Information System (INIS)

    Sopena, Fatima; Villaverde, Jaime; Maqueda, Celia; Morillo, Esmeralda

    2011-01-01

    Highlights: → Herbicide photodegradation studies using ethylcellulose-microencapsulated formulations (ECF) in soil and water. → Greater herbicide photo-protection observed from EFC than from its commercial form. → Photo-protective effect due to the gradual herbicide release and the presence of ethylcellulose. → Herbicide photo-stability conditioned by soil colloidal components, especially by goethite and humic acids. → EFC could reduce the field herbicide losses by photolysis. - Abstract: Ethylcellulose-microencapsulated formulations (ECFs) of norflurazon have been shown to reduce leaching, maintaining a threshold concentration in the topsoil than the commercial formulation (CF). Since photodegradation contributes to field dissipation of norflurazon, the objective of the present work was to study if such formulations can also protect from its photodescomposition. For this purpose, aqueous solutions of CF and ECFs, containing the most important soil components (goethite, humic and fulvic acids and montmorillonite) were tested. To get a more realistic approach, studies in soil were also performed. The results were well explained by a simple first order model. DT 50 value was 3 h for CF under irradiation, which was considerably lower than those corresponding to the systems where ECF was used (35 h for ECF; 260 h for ECF-goethite; 53 h for ECF-humic acids; 33 h for ECF-montmorillonite; and 28 h for ECF-fulvic acids). ECF protected against photodegradation in both aqueous solution and soil due to the gradual release of the herbicide, which reduced the herbicide available to be photodegraded. These lab-scale findings proved that ECF could reduce the herbicide dosage, minimizing its photolysis, which would be especially advantageous during the first hours after foliar and soil application.

  16. The reliability of finite element analysis results of the low impact test in predicting the energy absorption performance of thin-walled structures

    Energy Technology Data Exchange (ETDEWEB)

    Alipour, R.; Nejadx, Farokhi A.; Izman, S. [Universiti Teknologi Malaysia, Johor Bahru (Malaysia)

    2015-05-15

    The application of dual phase steels (DPS) such as DP600 in the form of thin-walled structure in automotive components is being continuously increased as vehicle designers utilize modern steel grades and low weight structures to improve structural performance, make automotive light and reinforce crash performance. Preventing cost enhancement of broad investigations in this area can be gained by using computers in structural analysis in order to substitute lots of experiments with finite element analysis (FEA). Nevertheless, it necessitates to be certified that selected method including element type and solution methodology is capable of predicting real condition. In this paper, numerical and experimental studies are done to specify the effect of element type selection and solution methodology on the results of finite element analysis in order to investigate the energy absorption behavior of a DP600 thin-walled structure with three different geometries under a low impact loading. The outcomes indicated the combination of implicit method and solid elements is in better agreement with the experiments. In addition, using a combination of shell element types with implicit method reduces the time of simulation remarkably, although the error of results compared to the experiments increased to some extent.

  17. Eficiência e seletividade dos herbicidas trifloxysulfuron-sodium + ametryne e hexazinone + diuron em função da tecnologia de aplicação e do manejo mecânico da palha de cana-de-açúcar na linha de plantio Efficiency and selectivity of trifloxysulfuron sodium + ametryne and hexazinone + diuron herbicide as a result of application technology and mechanical management of sugarcane straw in the crop row

    Directory of Open Access Journals (Sweden)

    C.D.G. Maciel

    2008-01-01

    the crop row, two experiments were conducted at Parálcool Sugar Mill S/A in Paraguaçu Paulista/SP. In Experiment 1, twelve treatments arranged in a 2 x 2 x 3 factorial scheme were performed, with four replications to evaluate the presence and absence of sugarcane straw in the crop row, and use of the herbicides trifloxysulfuron sodium + ametryne (37 + 1463 g ha-1 and 0.2% v/v of Aterbaneâ and diuron + hexazinone (330 + 1170 g ha-1 and 0.2% v/v of Aterbaneâ and spray nozzles XR11002-VS (128 L ha-1, AI11002-VS (200 L ha-1 and TF-VP5 (310 L ha 1. In Experiment 2, The application of spraying solution on sugarcane and Digitaria horizontalis plants, generated by the combination of the herbicides and the spray nozzles, was monitored by using a tracer solution constituted by coloring FDC-1 + herbicide. The results suggest that the crop straw provided excellent control of the infesting species, even in the absence of herbicide treatment. For D. horizontalis (6 leaves to 1-2 tillers and Brachiaria decumbens (2 to 6 leaves chemical control was efficient (>91% in the rows without straw, after 14 DAA (days after application for the herbicides and spray nozzles studied. D. horizontalis was more quickly controlled at 7 DAA by using trifloxysulfuron sodium + ametryne with AI11002-VS spray nozzle. Crop injury was observed up to 21 DAA, becoming more intense when diuron + hexazinone combinedwith AI11002-VS and TF-VP5 nozzle were used, due to higher herbicide deposition on the crop leaves.

  18. The role of herbicides in the erosion of salt marshes in eastern England

    International Nuclear Information System (INIS)

    Mason, C.F.; Underwood, G.J.C.; Baker, N.R.; Davey, P.A.; Davidson, I.; Hanlon, A.; Long, S.P.; Oxborough, K.; Paterson, D.M.; Watson, A.

    2003-01-01

    Herbicide run-off stresses saltmarsh diatoms and higher plants and may increase erosion. - Laboratory studies and field trials were conducted to investigate the role of herbicides on saltmarsh vegetation, and their possible significance to saltmarsh erosion. Herbicide concentrations within the ranges present in the aquatic environment were found to reduce the photosynthetic efficiency and growth of both epipelic diatoms and higher saltmarsh plants in the laboratory and in situ. The addition of sublethal concentrations of herbicides resulted in decreased growth rates and photosynthetic efficiency of diatoms and photosynthetic efficiency of higher plants. Sediment stability also decreased due to a reduction in diatom EPS production. There was qualitative evidence that diatoms migrated deeper into the sediment when the surface was exposed to simazine, reducing surface sediment stability by the absence of a cohesive biofilm. Sediment loads on leaves severely reduced photosynthesis in Limonium vulgare. This, coupled with reduced carbon assimilation from the effects of herbicides, could have large negative consequences for plant productivity and over winter survival of saltmarsh plants. The data support the hypothesis that sublethal herbicide concentrations could be playing a role in the increased erosion of salt marshes that has occurred over the past 40 years

  19. Herbicide effects on the growth and photosynthetic efficiency of Cassiopea maremetens.

    Science.gov (United States)

    Rowen, David J; Templeman, Michelle A; Kingsford, Michael J

    2017-09-01

    Herbicides from agricultural run-off have been measured in coastal systems of the Great Barrier Reef over many years. Non-target herbicide exposure, especially photosystem II herbicides has the potential to affect seagrasses and other marine species. The symbiotic benthic jellyfish Cassiopea maremetens is present in tropical/sub-tropical estuarine and marine environments. Jellyfish (n = 8 per treatment) were exposed to four separate concentrations of agricultural formulations of diuron or hexazinone to determine their sensitivity and potential for recovery to pulsed herbicide exposure. Jellyfish growth, symbiont photosynthetic activity and zooxanthellae density were analysed for herbicide-induced changes for 7 days followed by a 7 day recovery period. Both the jellyfish and endosymbiont were more sensitive to diuron than hexazinone. The 7-day EC 50 for jellyfish growth was 0.35 μg L -1 for Diuron and 17.5 μg L -1 for Hexazinone respectively. Diuron exposure caused a significant decrease (p diuron and hexazinone caused significant decreases in photosynthetic efficiency (effective quantum yield) in all treatment concentrations (0.1 μg L -1 and above) and this effect continued in the post-exposure period. As this species is frequently found in near-shore environments, they may be particularly vulnerable to herbicide run-off. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Contribution of transformation products towards the total herbicide toxicity to tropical marine organisms.

    Science.gov (United States)

    Mercurio, Philip; Eaglesham, Geoff; Parks, Stephen; Kenway, Matt; Beltran, Victor; Flores, Florita; Mueller, Jochen F; Negri, Andrew P

    2018-03-19

    The toxicity of herbicide degradation (transformation) products is rarely taken into account, even though these are commonly detected in the marine environment, sometimes at concentrations higher than the parent compounds. Here we assessed the potential contribution of toxicity by transformation products of five photosystem II herbicides to coral symbionts (Symbiodinium sp.), the green algae Dunaliella sp., and prawn (Penaeus monodon) larvae. Concentration-dependent inhibition of photosynthetic efficiency (∆F/F m ') was observed for all herbicides in both microalgal species. The toxicity of solutions of aged diuron solutions containing transformation products to Symbiodinium sp. and Dunaliella sp. was greater than could be explained by the concentrations of diuron measured, indicating transformation products contributed to the inhibition of ∆F/F m '. However, the toxicity of aged atrazine, simazine, hexazinone, and ametryn solutions could be explained by the concentration of parent herbicide, indicating no contribution by transformation products. Prawn larval metamorphosis was not sensitive to the herbicides, but preliminary results indicated some toxicity of the transformation products of atrazine and diuron. Risk assessments should take into account the contribution of herbicide transformation products; however, further studies are clearly needed to test the toxicity of a far wider range of transformation products to a representative diversity of relevant taxa.

  1. Crystal structure of plant acetohydroxyacid synthase, the target for several commercial herbicides.

    Science.gov (United States)

    Garcia, Mario Daniel; Wang, Jian-Guo; Lonhienne, Thierry; Guddat, Luke William

    2017-07-01

    Acetohydroxyacid synthase (AHAS, EC 2.2.1.6) is the first enzyme in the branched-chain amino acid biosynthesis pathway. Five of the most widely used commercial herbicides (i.e. sulfonylureas, imidazolinones, triazolopyrimidines, pyrimidinyl-benzoates and sulfonylamino-cabonyl-triazolinones) target this enzyme. Here we have determined the first crystal structure of a plant AHAS in the absence of any inhibitor (2.9 Å resolution) and it shows that the herbicide-binding site adopts a folded state even in the absence of an inhibitor. This is unexpected because the equivalent regions for herbicide binding in uninhibited Saccharomyces cerevisiae AHAS crystal structures are either disordered, or adopt a different fold when the herbicide is not present. In addition, the structure provides an explanation as to why some herbicides are more potent inhibitors of Arabidopsis thaliana AHAS compared to AHASs from other species (e.g. S. cerevisiae). The elucidation of the native structure of plant AHAS provides a new platform for future rational structure-based herbicide design efforts. The coordinates and structure factors for uninhibited AtAHAS have been deposited in the Protein Data Bank (www.pdb.org) with the PDB ID code 5K6Q. © 2017 Federation of European Biochemical Societies.

  2. Resistance risk assessment within herbicide authorisation--a call for sensitivity data.

    Science.gov (United States)

    Ulber, Lena; Nordmeyer, Henning; Zwerger, Peter

    2013-02-01

    In most European countries, the risk of herbicide resistance is assessed as part of the authorisation of herbicides in accordance with EPPO Standard PP 1/213(2). Because the susceptibility of weed populations to a certain herbicide may vary greatly, one part of resistance risk assessment is the testing for sensitivity variation among different populations of target weed species with a high resistance risk. This paper emphasises the importance of sensitivity data provision with regard to the recent EU Regulation (EC) 1107/2009 concerning the placing of plant protection products on the market and outlines the main technical requirements for sensitivity data. A useful principle is that sensitivity data should be provided for all herbicides with a high resistance risk regardless of whether resistance has already evolved against the herbicidal substance. Methodical details regarding the generation of sensitivity data are discussed, together with remaining questions that will need to be addressed if a harmonised assessment of herbicide resistance risk is to be achieved. Copyright © 2012 Society of Chemical Industry.

  3. Toxicity of herbicides used in the sugarcane crop to diazotrophic bacterium Herbaspirillum seropedicae

    Directory of Open Access Journals (Sweden)

    Sergio de Oliveira Procópio

    2014-10-01

    Full Text Available The objective of this work was to identify herbicides used in the sugarcane crop that affects neither the growth, the development, of nor the process of biological nitrogen fixation (BNF by the diazotrophic bacterium Herbaspirillum seropedicae. Eighteen herbicides (paraquat, ametryne, tebuthiuron, amicarbazone, diuron, metribuzin, [hexazinone + diuron], [hexazinone + clomazone], clomazone, isoxaflutole, sulfentrazone, oxyfluorfen, imazapic, imazapyr, [trifloxysulfuron sodium + ametryne], glyphosate, MSMA e 2,4-D were tested in their respective commercial doses regarding their impact on the growth of the bacteria in liquid medium DIGs. For this, we determined the duration of lag phase, generation time and maximum cell density of H. seropedicae, calculated from optical density data obtained at regular intervals during the incubation of cultures for 33 h at 32oC. We also evaluated the impact of herbicides on nitrogenase activity of H. seropedicae grown in semi-solid N-free JNFb medium. The effects of herbicides on the growth variables and the ARA were compared with the untreated control by Dunnett test. A completely randomized design was used. The herbicides paraquat, imazapyr, ametryne, glyphosate and oxyfluorfen inhibited the growth of H. seropedicae in vitro. Ametryne, oxyfluorfen and glyphosate caused a small reduction in the duration of the lag phase of diazotrophic bacteria H. seropedicae. Oxyfluorfen, ametryne and imazapyr resulted in increased the generation time by H. seropedicae. Glyphosate promoted drastic reduction in biological nitrogen fixation in vitro by H. seropedicae. The other tested herbicides did not affect the growth or the same BNF by H. seropedicae.

  4. Non-specific activities of the major herbicide-resistance gene BAR.

    Science.gov (United States)

    Christ, Bastien; Hochstrasser, Ramon; Guyer, Luzia; Francisco, Rita; Aubry, Sylvain; Hörtensteiner, Stefan; Weng, Jing-Ke

    2017-12-01

    Bialaphos resistance (BAR) and phosphinothricin acetyltransferase (PAT) genes, which convey resistance to the broad-spectrum herbicide phosphinothricin (also known as glufosinate) via N-acetylation, have been globally used in basic plant research and genetically engineered crops 1-4 . Although early in vitro enzyme assays showed that recombinant BAR and PAT exhibit substrate preference toward phosphinothricin over the 20 proteinogenic amino acids 1 , indirect effects of BAR-containing transgenes in planta, including modified amino acid levels, have been seen but without the identification of their direct causes 5,6 . Combining metabolomics, plant genetics and biochemical approaches, we show that transgenic BAR indeed converts two plant endogenous amino acids, aminoadipate and tryptophan, to their respective N-acetylated products in several plant species. We report the crystal structures of BAR, and further delineate structural basis for its substrate selectivity and catalytic mechanism. Through structure-guided protein engineering, we generated several BAR variants that display significantly reduced non-specific activities compared with its wild-type counterpart in vivo. The transgenic expression of enzymes can result in unintended off-target metabolism arising from enzyme promiscuity. Understanding such phenomena at the mechanistic level can facilitate the design of maximally insulated systems featuring heterologously expressed enzymes.

  5. Efficient biotransformation of herbicide diuron by bacterial strain Micrococcus sp. PS-1.

    Science.gov (United States)

    Sharma, Priyanka; Chopra, Adity; Cameotra, Swaranjit Singh; Suri, C Raman

    2010-11-01

    A Gram-positive, Micrococcus sp. strain PS-1 capable of utilizing phenylurea herbicide diuron as a sole carbon source at a high concentration (up to 250 ppm) was isolated from diuron storage site by selective enrichment study. The taxonomic characterization with 16S rRNA gene sequencing (1,477 bp) identified PS-1 as a member of Micrococcus sp. It was studied for the degradation of diuron and a range of its analogues (monuron, linuron, monolinuron, chlortoluron and fenuron). The shake flasks experiments demonstrated fast degradation of diuron (up to 96% at 250 ppm within 30 h incubation) with the addition of small quantity (0.01%) of non-ionic detergent. The relative degradation profile by the isolate was in the order of fenuron > monuron > diuron > linuron > monolinuron > chlortoluron. Further, the biochemical characterization of catabolic pathway by spectroscopic and chromatographic techniques demonstrated that the degradation proceeded via formation of dealkylated metabolites to form 3,4-dichloroaniline (3,4-DCA). It was the major metabolite formed, associated with profound increase in degradation kinetics in presence of appropriate additive.

  6. Aldo-keto reductase enzymes detoxify glyphosate and improve herbicide resistance in plants.

    Science.gov (United States)

    Vemanna, Ramu S; Vennapusa, Amaranatha Reddy; Easwaran, Murugesh; Chandrashekar, Babitha K; Rao, Hanumantha; Ghanti, Kirankumar; Sudhakar, Chinta; Mysore, Kirankumar S; Makarla, Udayakumar

    2017-07-01

    In recent years, concerns about the use of glyphosate-resistant crops have increased because of glyphosate residual levels in plants and development of herbicide-resistant weeds. In spite of identifying glyphosate-detoxifying genes from microorganisms, the plant mechanism to detoxify glyphosate has not been studied. We characterized an aldo-keto reductase gene from Pseudomonas (PsAKR1) and rice (OsAKR1) and showed, by docking studies, both PsAKR1 and OsAKR1 can efficiently bind to glyphosate. Silencing AKR1 homologues in rice and Nicotiana benthamiana or mutation of AKR1 in yeast and Arabidopsis showed increased sensitivity to glyphosate. External application of AKR proteins rescued glyphosate-mediated cucumber seedling growth inhibition. Regeneration of tobacco transgenic lines expressing PsAKR1 or OsAKRI on glyphosate suggests that AKR can be used as selectable marker to develop transgenic crops. PsAKR1- or OsAKRI-expressing tobacco and rice transgenic plants showed improved tolerance to glyphosate with reduced accumulation of shikimic acid without affecting the normal photosynthetic rates. These results suggested that AKR1 when overexpressed detoxifies glyphosate in planta. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  7. Maternal and fetal toxicity of Wistar rats exposed to herbicide metolachlor

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    Kátia Cristina de Melo Tavares Vieira

    2016-07-01

    Full Text Available Metolachlor is a selective pre-emergent herbicide widely used in agriculture to control weeds. The aim of this study was to evaluate the possible effects of metolachlor on reproductive performance of adult rats, as well as its teratogenic potential when administered during the period of organogenesis. Pregnant adult female rats were allocated into 4 experimental groups (n = 10 group-1, that received 0 (control; 150 (TA; 300 (TB; or 1000 mg kg-1 bw day-1 (TC of metolachlor, by gavage, from the 6th to 15th gestational day (GD. There is reduction in the weight gain of the animals from TB and TC groups compared to the control group. Liver and placenta weights were reduced in TB and TC groups, respectively, while the percentage of post-implantation loss was increased in the TC group. There were no external malformations in either rat of the control or treated groups. However, an increased incidence of skeletal anomalies and visceral anomalies (especially in the urogenital system was observed in TC group. These results demonstrate that exposure of pregnant rats to metolachlor can lead to signs of general toxicity, late embryonic losses and congenital anomalies.

  8. Effect of some herbicides on weeds and vines in mother plantation of Cabernet sauvignon

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    N.Prodanova-Marinova

    2016-09-01

    Full Text Available Abstract. To maintain soil surface clean of weeds in the parent vineyard for producing cuttings for scions, the efficiency and selectivity of Gardoprim plus Gold (312.5 g/l s-metolachlor + 187.5 g/l terbuthylazine, Wing P (pendimethalin 250 g/l + dimethenamid P 212.5 g/l and Lumax 538 SC (375 g/l s-metolachlor + 125 g/l terbuthylazine + 337.5 g/l mesotrione at doses of 0.4 and 0.6 l/da was studied. Lumax 538 SC, Wing P and Gardoprim Plus Gold controlling efficiently annual weeds established in parent vineyard, except Xanthium strumarium L.. Lumax 538 SC and Gardoprim plus Gold showed long-term (90 days activity. Wing P activity decreases after the thirtieth day. The tested herbicides do not damage the buds and do not lead to a reduction of shoots developed from them. Lumax 538 SC and Gardoprim plus Gold at doses of 0.4 and 0.6 l/da and Wing P at dose of 0.4 l/da do not inhibit the growth of shoots. The largest number of cuttings for scions were obtained after treatment with Lumax 538 SC.

  9. Determination of diphenylether herbicides in water samples by solid-phase microextraction coupled to liquid chromatography.

    Science.gov (United States)

    Sheu, Hong-Li; Sung, Yu-Hsiang; Melwanki, Mahaveer B; Huang, Shang-Da

    2006-11-01

    Solid-phase microextraction (SPME) coupled to LC for the analysis of five diphenylether herbicides (aclonifen, bifenox, fluoroglycofen-ethyl, oxyfluorfen, and lactofen) is described. Various parameters of extraction of analytes onto the fiber (such as type of fiber, extraction time and temperature, pH, impact of salt and organic solute) and desorption from the fiber in the desorption chamber prior to separation (such as type and composition of desorption solvent, desorption mode, soaking time, and flush-out time) were studied and optimized. Four commercially available SPME fibers were studied. PDMS/divinylbenzene (PDMS/DVB, 60 microm) and carbowax/ templated resin (CW/TPR, 50 microm) fibers were selected due to better extraction efficiencies. Repeatability (RSD, 0.994), and detection limit (0.33-1.74 and 0.22-1.94 ng/mL, respectively, for PDMS/DVB and CW/TPR) were investigated. Relative recovery (81-104% for PDMS/DVB and 83-100% for CW/TPR fiber) values have also been calculated. The developed method was successfully applied to the analysis of river water and water collected from a vegetable garden.

  10. Simultaneous quantification of acetanilide herbicides and their oxanilic and sulfonic acid metabolites in natural waters.

    Science.gov (United States)

    Heberle, S A; Aga, D S; Hany, R; Müller, S R

    2000-02-15

    This paper describes a procedure for simultaneous enrichment, separation, and quantification of acetanilide herbicides and their major ionic oxanilic acid (OXA) and ethanesulfonic acid (ESA) metabolites in groundwater and surface water using Carbopack B as a solid-phase extraction (SPE) material. The analytes adsorbed on Carbopack B were eluted selectively from the solid phase in three fractions containing the parent compounds (PCs), their OXA metabolites, and their ESA metabolites, respectively. The complete separation of the three compound classes allowed the analysis of the neutral PCs (acetochlor, alachlor, and metolachlor) and their methylated OXA metabolites by gas chromatography/mass spectrometry. The ESA compounds were analyzed by high-performance liquid chromatography with UV detection. The use of Carbopack B resulted in good recoveries of the polar metabolites even from large sample volumes (1 L). Absolute recoveries from spiked surface and groundwater samples ranged between 76 and 100% for the PCs, between 41 and 91% for the OXAs, and between 47 and 96% for the ESAs. The maximum standard deviation of the absolute recoveries was 12%. The method detection limits are between 1 and 8 ng/L for the PCs, between 1 and 7 ng/L for the OXAs, and between 10 and 90 ng/L for the ESAs.

  11. Fate of the herbicides glyphosate, glufosinate-ammonium, phenmedipham, ethofumesate and metamitron in two Finnish arable soils.

    Science.gov (United States)

    Laitinen, Pirkko; Siimes, Katri; Eronen, Liisa; Rämö, Sari; Welling, Leena; Oinonen, Seija; Mattsoff, Leona; Ruohonen-Lehto, Marja

    2006-06-01

    The fate of five herbicides (glyphosate, glufosinate-ammonium, phenmedipham, ethofumesate and metamitron) was studied in two Finnish sugar beet fields for 26 months. Soil types were sandy loam and clay. Two different herbicide-tolerant sugar beet cultivars and three different herbicide application schedules were used. Meteorological data were collected throughout the study and soil properties were thoroughly analysed. An extensive data set of herbicide residue concentrations in soil was collected. Five different soil depths were sampled. The study was carried out using common Finnish agricultural practices and represents typical sugar beet cultivation conditions in Finland. The overall observed order of persistence was ethofumesate > glyphosate > phenmedipham > metamitron > glufosinate-ammonium. Only ethofumesate and glyphosate persisted until the subsequent spring. Seasonal variation in herbicide dissipation was very high and dissipation ceased almost completely during winter. During the 2 year experiment no indication of potential groundwater pollution risk was obtained, but herbicides may cause surface water pollution. Copyright (c) 2006 Society of Chemical Industry

  12. Ecotoxicidade de herbicidas para a macrófita aquática (Azolla caroliniana Ecotoxicity of herbicides for the aquatic macrophyte (Azolla caroliniana

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    A.F. Silva

    2012-09-01

    Full Text Available Os objetivos deste estudo foram avaliar Azolla caroliniana como planta-teste em estudos ecotoxicológicos e estimar a CL50;7d dos herbicidas 2,4-D, glyphosate, clomazone e oxyfluorfen. As plantas foram aclimatadas em sala de bioensaio. Para isso, foram selecionadas cinco plantas em 50 mL de meio de cultivo Hoagland. Após esse período, foram adicionados 50 mL de Hoagland mais o herbicida, completando o volume para 100 mL. A concentração letal de 50% (CL50;7d para A. caroliniana exposta ao herbicida 2,4-D foi de 708,35 mg L-1; ao glyphosate (formulação Scout®, de 23,66 mg L-1; ao glyphosate (formulação Trop®, de 38,91 mg L-1; ao clomazone, de 129,63 mg L-1; e ao oxyfluorfen, de 80,50 mg L-1. Os herbicidas glyphosate (Scout® e Trop® e oxyflourfen foram classificados como moderadamente tóxicos a A. caroliniana, e o clomazone e o 2,4-D, como praticamente não tóxicos. Conclui-se que A. caroliniana pode ser utilizada como planta bioindicadora de herbicidas à base de glyphosate e oxyfluorfen.The objectives of this study were to evaluate Azolla caroliniana as test plant in ecotoxicological studies and to estimate the LC50; 7d of the herbicides 2,4 D , glyphosate, and clomazone oxyfluorfen. The plants were acclimatized in the bioassay room. Five plants in 50 mL Hoagland culture medium were selected. After that, 50 mL of Hoagland and the herbicide were added, completing the volume to 100 mL. The 50% lethal concentration (LC50; 7d for A. caroliniana exposed to the herbicide 2,4- D, was 708.35 mg L-1; to glyphosate (formulation Scout®, 23.66 mg L-1; to glyphosate (formulation Trop®, 38.91 mg L-1; to clomazone, 129.63 mg L-1; and to oxyflourfen, 80.50 mg L-1. The herbicides glyphosate (Scout® and Trop® and oxyflourfen were classified as moderately toxic to A. caroliniana, while clomazone and 2,4-D were classified as practically non-toxic. It was concluded that A. caroliniana plants can be used as bio-indicators for glyphosate and

  13. Determination of Chlorophenoxy Acid Methyl Esters and Other Chlorinated Herbicides by GC High-resolution QTOFMS and Soft lonization

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    Viorica Lopez-Avila

    2015-01-01

    Full Text Available Gas chromatography with quadrupole time-of-flight mass spectrometry (GC-QTOFMS and soft ionization generated by a rare-gas plasma is described here for the determination of various chlorophenoxy acid methyl esters and a few chlorinated herbicides. This plasma-based, wavelength-selectable ionization source, which can use Xe, Kr, Ar, Ne, or He as the plasma gas, enables ionization of GC-amenable compounds with ionization energies below 8.4, 10, 11.6, 16.5, or 22.4 eV, respectively. The advantages of soft ionization include enhanced molecular ions, reduced fragmentation, and reduced background noise as compared to electron ionization. In the study presented here for two plasma gases, we demonstrate that Kr plasma, which is softer than Ar plasma, yields molecular ions with a relative intensity >60% for 11 of the 16 test compounds. When using this “tunable” plasma to ionize the analytes, there is the possibility for selective ionization and less fragmentation, which may lead to increased sensitivity and may help structure elucidation, especially when using high-resolution mass spectrometry that generates accurate masses within a few parts per million (ppm mass errors. Data generated with the Ar plasma and real matrices such as a peppermint extract, a plum extract, and an orange peel extract, spiked with 16 test compounds, indicate that the test compounds can be detected at 1-10 pg/µL of extract, and compounds such as menthone, limonene, eucalyptol, pinene, caryophylene, and other C 15 H 24 isomers, which are present in the peppermint and the orange peel extracts at ppm to percent levels, do not appear to interfere with the determination of the chlorophenoxy acid methyl esters or the chlorinated herbicides, although there were matrix effects when the test compounds were spiked at 1-10 pg/µL of extract.

  14. Ecotoxicological assessment of the herbicide Winner Top and its active substances-are the other formulants truly inert?

    Science.gov (United States)

    Queirós, Libânia; Vidal, Tânia; Nogueira, António J A; Gonçalves, Fernando J M; Pereira, Joana Luísa

    2018-05-03

    Formulants used in Plant Protection Products (PPPs) to promote their efficiency are normally undisclosed in the PPP documentation, unless they bear a human health or environmental hazardous potential per se. PPP regulation also demands the assessment of putative interactions among formulants within each product recipe and consequent effects, but these results are often unavailable. Such a case is that of the herbicide Winner Top (Selectis®, Portugal), which we selected as a model commercial formulation in the present study specifically aiming at (i) characterising its aquatic toxicity towards sensitive eco-receptors (Raphidocelis subcapitata, Chlorella vulgaris, Lemna minor and Lemna gibba), as well as that of its active substances (a.s.) nicosulfuron and terbuthylazine; (ii) comparing the ecotoxicity among the commercial formulation, the corresponding mixture of its a.s. and this a.s.'s mixture increasingly enriched with the formulants. Single chemical testing revealed that terbuthylazine was the strongest microalgae growth inhibitor and nicosulfuron was the strongest macrophyte growth inhibitor. On the other hand, the commercial formulation was consistently less toxic than the corresponding mixture of the a.s., suggesting that Winner Top formulants (72.9% of the commercial formulation) interact with the a.s., promoting less than additive effects in the selected non-target species. Importantly, this environmentally protective effect of the formulation can be apparent. Because macrophytes share most physiological features with the weeds targeted by the studied herbicide, it is likely that increased application doses are required to reach desired efficacy levels with the consequent detrimental increase of PPP residues load in edge-of-field freshwater ecosystems.

  15. Pseudomonas fluorescens strains selectively suppress annual bluegrass (Poa annua L.)

    Science.gov (United States)

    Annual bluegrass (Poa annua L.) is a cool-season annual grass that is a major weed species in turf, turfgrass-seed production, sod production, and golf courses of the western United States. There are few selective herbicides available for the management of annual bluegrass. While the life cycles o...

  16. Spatial variability of herbicide mobilisation and transport at catchment scale: insights from a field experiment

    Directory of Open Access Journals (Sweden)

    T. Doppler

    2012-07-01

    Full Text Available During rain events, herbicides can be transported from their point of application to surface waters, where they may harm aquatic organisms. Since the spatial pattern of mobilisation and transport is heterogeneous, the contributions of different fields to the herbicide load in the stream may vary considerably within one catchment. Therefore, the prediction of contributing areas could help to target mitigation measures efficiently to those locations where they reduce herbicide pollution the most.

    Such spatial predictions require sufficient insight into the underlying transport processes. To improve the understanding of the process chain of herbicide mobilisation on the field and the subsequent transport through the catchment to the stream, we performed a controlled herbicide application on corn fields in a small agricultural catchment (ca. 1 km2 with intensive crop production in the Swiss Plateau. Water samples were collected at different locations in the catchment (overland flow, tile drains and open channel for two months after application in 2009, with a high temporal resolution during rain events. We also analysed soil samples from the experimental fields and measured discharge, groundwater level, soil moisture and the occurrence of overland flow at several locations. Several rain events with varying intensities and magnitudes occurred during the study period. Overland flow and erosion were frequently observed in the entire catchment. Infiltration excess and saturation excess overland flow were both observed. However, the main herbicide loss event was dominated by infiltration excess.

    Despite the frequent and wide-spread occurrence of overland flow, most of this water did not reach the channel directly, but was retained in small depressions in the catchment. From there, it reached the stream via macropores and tile drains. Manholes of the drainage system and storm drains for road and farmyard runoff acted as

  17. The herbicide Glyphosate affects nitrification in the Elbe estuary, Germany

    Science.gov (United States)

    Sanders, Tina; Lassen, Stephan

    2015-04-01

    The Elbe River is one of the biggest European rivers discharging into the North Sea. It also transports high amounts of nutrients and pollutants like pesticides. Important source regions of both nutrients and pollutants are located within the river catchment, which is dominated by agricultural land-use. From these agricultural soils, pesticides can be carried via the river and estuary into the North Sea. Glyphosate (N-(phosphonomethyl) glycine) is the most commonly used herbicide worldwide and mainly used to regulate unwanted plant growth and for the expedition of crop ripening. In Germany, ~ 6000 tons of glyphosate are applied yearly in agriculture and private use. Glyphosate is degradable by microorganisms and has a half-life in water of 35 to 60 days. This herbicide specifically inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), an enzyme that catalyzes the biosynthesis of essential aromatic amino acids in plants, fungi, and bacteria. Nitrifying bacteria, which play an important role in the internal nitrogen cycling in the Elbe estuary, also possess this enzyme. The aim of our study was to quantify the concentration of glyphosate in water and sediment samples of the Elbe to get an overview about relevant environmental levels and to assess the impact of glyphosate on inhibition of nitrifying activities. To quantify the effect of glyphosate on nitrification activity, natural samples as well as pure cultures of Nitrosomonas europea (strain Nm50) were incubated with different concentrations of glyphosate over a period of some weeks. The nitrifying activity was determined according to changes of the nitrite and nitrate concentration as well as the cell number. Glyphosate was detectable in water and sediment samples in the Elbe estuary with up to 5 ppb mainly in the Port of Hamburg region. In both incubation experiments an inhibiting effect of glyphosate on nitrification could be shown. The incubated natural water sample was affected by a glyphosate

  18. Teaching Sustainable Water Resources and Low Impact Development: A Project Centered Course for First-Year Undergraduates

    Science.gov (United States)

    Cianfrani, C. M.

    2009-12-01

    Teaching Sustainable Water Resources and Low Impact Development: A Project Centered Course for First-Year Undergraduates Christina M. Cianfrani Assistant Professor, School of Natural Science, Hampshire College, 893 West Avenue, Amherst, MA 01002 Sustainable water resources and low impact development principles are taught to first-year undergraduate students using an applied design project sited on campus. All students at Hampshire College are required to take at least one natural science course during their first year as part of their liberal arts education. This requirement is often met with resistance from non-science students. However, ‘sustainability’ has shown to be a popular topic on campus and ‘Sustainable Water Resources’ typically attracts ~25 students (a large class size for Hampshire College). Five second- or third-year students are accepted in the class as advanced students and serve as project leaders. The first-year students often enter the class with only basic high school science background. The class begins with an introduction to global water resources issues to provide a broad perspective. The students then analyze water budgets, both on a watershed basis and a personal daily-use basis. The students form groups of 4 to complete their semester project. Lectures on low impact design principles are combined with group work sessions for the second half of the semester. Students tour the physical site located across the street from campus and begin their project with a site analysis including soils, landcover and topography. They then develop a building plan and identify preventative and mitigative measures for dealing with stormwater. Each group completes TR-55 stormwater calculations for their design (pre- and post-development) to show the state regulations for quantity will be met with their design. Finally, they present their projects to the class and prepare a formal written report. The students have produced a wide variety of creative

  19. Using Bioassays and Species Sensitivity Distributions to Assess Herbicide Toxicity towards Benthic Diatoms

    Science.gov (United States)

    Larras, Floriane; Bouchez, Agnès; Rimet, Frédéric; Montuelle, Bernard

    2012-01-01

    Although benthic diatoms are widely used in ecological studies of aquatic systems, there is still a dearth of data concerning species sensitivities towards several contaminants. Within the same community, different species may respond differently depending on their physiological and ecological characteristics. This lack of knowledge makes specific appropriate risk assessment impossible. To find out whether species sensitivity distribution (SSD) could be used to estimate the risk of herbicide toxicity for diatoms, we need to know whether their sensitivity depends on their physiological and ecological characteristics. We carried out single-species bioassays on 11 diatom species exposed to 8 herbicides. Dose-responses relationships were used to extrapolate the Effective Concentration 5 (EC5) and the Effective Concentration 50 (EC50) for each exposure. These data were used to fit a SSD curve for each herbicide, and to determine the Hazardous concentration 5 (HC5) and 50 (HC50). Our results revealed a high level of variability of the sensitivity in the set of species tested. For photosystem-II inhibitor (PSII) herbicides, diatoms species displayed a typical grouping of sensitivity levels consistent with their trophic mode and their ecological guild. N-heterotroph and “motile” guild species were more tolerant of PSII inhibitors, while N-autotroph and “low profile” guild species were more sensitive. Comprehensive SSD curves were obtained for 5 herbicides, but not for sulfonylurea herbicides or for dimetachlor, which had toxicity levels that were below the range of concentration tested. The SSD curves provided the following ranking of toxicity: diuron> terbutryn> isoproturon> atrazine> metolachlor. The HC that affected 5% of the species revealed that, even at the usual environmental concentrations of herbicides, diatom assemblages could be affected, especially by isoproturon, terbutryn, and diuron. PMID:22952981

  20. Structure effect on the interaction of phenylurea herbicides with model biomembrane as an environmental mobility parameter.

    Science.gov (United States)

    Librando, Vito; Forte, Stefano; Sarpietro, Maria G

    2004-01-15

    During recent years, intensive use of herbicides has raised increasing concern mainly due to their massive pollution of the environment. As these herbicides are directly or indirectly toxic to a wide range of organisms, their potential for contaminating soil, surface water, and groundwater makes these xenobiotics of special interest from a health and environmental point of view. Knowledge of the mechanisms by which they exert their toxic effects is becoming a need. Because of the herbicides' lipophilicity, a possible site of interaction in the cell is represented by biomembranes. The interaction of four herbicides, difenoxuron, diuron, linuron, and metoxuron, with model membranes constituted of dimyristoylphosphatidylcholine multilamellar vesicles was investigated by the differential scanning calorimetry technique. The aim was to study the effects exerted by an increasing amount of the examined compounds on thermotropic behavior of the model phospholipid membranes and to correlate the obtained results with structural features of the herbicides due to their environmental mobility. Among the herbicides studied, linuron is the most effective in perturbing the ordinate structure of vesicles forming phospholipids, whereas metoxuron is the least effective and the others exert an intermediate effect. Linuron exerts its effect both on the transition temperature of the gel to the liquid crystalline phase and on the enthalpy change. Difenoxuron, diuron, and metoxuron cause a change in the transition temperature but have an insignificant effect on the enthalpy change. The calorimetric results, correlated with the structural features of the herbicides, are consistent with their partition coefficient, log K(ow), suggesting that the more hydrophobic compound character causes a greater liposolubility and consequential cellular absorption with more effectiveness on the membrane order.

  1. Herbicide micropollutants in surface, ground and drinking waters within and near the area of Zagreb, Croatia.

    Science.gov (United States)

    Fingler, Sanja; Mendaš, G; Dvoršćak, M; Stipičević, S; Vasilić, Ž; Drevenkar, V

    2017-04-01

    The frequency and mass concentrations of 13 herbicide micropollutants (triazines, phenylureas, chloroacetanilides and trifluralin) were investigated during 2014 in surface, ground and drinking waters in the area of the city of Zagreb and its suburbs. Herbicide compounds were accumulated from water by solid-phase extraction using either octadecylsilica or styrene-divinylbenzene sorbent cartridges and analysed either by high-performance liquid chromatography with UV-diode array detector or gas chromatography with mass spectrometric detection. Atrazine was the most frequently detected herbicide in drinking (84 % of samples) and ground (61 % of samples) waters in mass concentrations of 5 to 68 ng L -1 . It was followed by metolachlor and terbuthylazine, the former being detected in 54 % of drinking (up to 15 ng L -1 ) and 23 % of ground (up to 100 ng L -1 ) waters, and the latter in 45 % of drinking (up to 20 ng L -1 ) and 26 % of ground (up to 25 ng L -1 ) water samples. Acetochlor was the fourth most abundant herbicide in drinking waters, detected in 32 % of samples. Its mass concentrations of 107 to 117 ng L -1 in three tap water samples were the highest of all herbicides measured in the drinking waters. The most frequently (62 % of samples) and highly (up to 887 ng L -1 ) detected herbicide in surface waters was metolachlor, followed by terbuthylazine detected in 49 % of samples in mass concentrations of up to 690 ng L -1 , and atrazine detected in 30 % of samples in mass concentrations of up to 18 ng L -1 . The seasonal variations in herbicide concentrations in surface waters were observed for terbuthylazine, metolachlor, acetochlor, chlortoluron and isoproturon with the highest concentrations measured from April to August.

  2. Effect of Rimsulfuron, Imazapic and Imazamox Herbicides on Broomrape (Orobanche aegyptiaca in Tomato (Lycopersicum esculentum

    Directory of Open Access Journals (Sweden)

    E. Kazerooni Monfared

    2016-01-01

    Full Text Available Experiments, in Petri dish and greenhouse, were carried out to investigate the efficiency of three herbicides (rimsulfuron, imazapic and imazamox in controling broomrape. In Petri dish study, herbicides were applied at 0.05, 0.25, 1.25, 6.25 and 31.25 micro-mole doses to broomrape seeds at germination stage without a host plant and adding GR24 as stimulator. In the greenhouse experiments, the efficiency of these herbicides to control broomrape in two varieties of tomato (Viva and Hyb.Petopride II was investigated. Treatments were four doses of rimsulfuron (25, 50, 75 and 100 g ai/ha, imazapic (5, 10, 15 and 20 g ai/ha and imazamox (0.4, 0.8, 1.2 and 1.6 g ai/ha at one, two and three applications. Results of Petri-dish experiments showed that rimsulfuron and imazapic significantly reduced radicle elongation of seedlings as compared to the control, while, imazamox did not have any effect on broomrape seed. Each dose was applied for one, two and three times with in 15, 29 and 43 days after within transplanting tomato seedlings. Results of pot experiments indicated that the responses of two tomato varieties herbicides were different. Viva was responsive to herbicidal effect and produced higher biomass than Hyb.Petopride II. Rimsulfuron was a suitable herbicide in tomato to control broomrape. Rimsulfuron at doses of 25, 50 and 75 g ai/ha (three times of application were the best doses, specially in viva were the best treatments for broomrape control and producing tomato biomass. Imazapic also, at 5 g ai/ha (two times of application and 10 g ai/ha (single application was an effective treatments in variety of viva. Imazamox treatments did not appear to be suitable herbicides in this study.

  3. Using bioassays and species sensitivity distributions to assess herbicide toxicity towards benthic diatoms.

    Directory of Open Access Journals (Sweden)

    Floriane Larras

    Full Text Available Although benthic diatoms are widely used in ecological studies of aquatic systems, there is still a dearth of data concerning species sensitivities towards several contaminants. Within the same community, different species may respond differently depending on their physiological and ecological characteristics. This lack of knowledge makes specific appropriate risk assessment impossible. To find out whether species sensitivity distribution (SSD could be used to estimate the risk of herbicide toxicity for diatoms, we need to know whether their sensitivity depends on their physiological and ecological characteristics. We carried out single-species bioassays on 11 diatom species exposed to 8 herbicides. Dose-responses relationships were used to extrapolate the Effective Concentration 5 (EC(5 and the Effective Concentration 50 (EC(50 for each exposure. These data were used to fit a SSD curve for each herbicide, and to determine the Hazardous concentration 5 (HC(5 and 50 (HC(50. Our results revealed a high level of variability of the sensitivity in the set of species tested. For photosystem-II inhibitor (PSII herbicides, diatoms species displayed a typical grouping of sensitivity levels consistent with their trophic mode and their ecological guild. N-heterotroph and "motile" guild species were more tolerant of PSII inhibitors, while N-autotroph and "low profile" guild species were more sensitive. Comprehensive SSD curves were obtained for 5 herbicides, but not for sulfonylurea herbicides or for dimetachlor, which had toxicity levels that were below the range of concentration tested. The SSD curves provided the following ranking of toxicity: diuron> terbutryn> isoproturon> atrazine> metolachlor. The HC that affected 5% of the species revealed that, even at the usual environmental concentrations of herbicides, diatom assemblages could be affected, especially by isoproturon, terbutryn, and diuron.

  4. Soil microbial communities and glyphosate decay in soils with different herbicide application history.

    Science.gov (United States)

    Guijarro, Keren Hernández; Aparicio, Virginia; De Gerónimo, Eduardo; Castellote, Martín; Figuerola, Eva L; Costa, José Luis; Erijman, Leonardo

    2018-04-11

    This study evaluates the glyphosate dissipation under field conditions in three types of soil, and aims to determine the importance of the following factors in the environmental persistence of herbicide: i) soil bacterial communities, ii) soil physicochemical properties, iii) previous exposure to the herbicide. A soil without previous record of GP application (P0) and two agricultural soils, with 5 and >10years of GP exposure (A5 and A10) were subjected to the application of glyphosate at doses of 3mg·kg -1 . The concentration of GP and AMPA was determined over time and the dynamics of soil bacterial communities was evaluated using 16S ARN ribosomal gene amplicon-sequencing. The GP exposure history affected the rate but not the extent of GP biodegradation. The herbicide was degraded rapidly, but P0 soil showed a dissipation rate significantly lower than soils with agricultural history. In P0 soil, a significant increase in the relative abundance of Bacteroidetes was observed in response to herbicide application. More generally, all soils displayed shifts in bacterial community structure, which nevertheless could not be clearly associated to glyphosate dissipation, suggesting the presence of redundant bacteria populations of potential degraders. Yet the application of the herbicide prompted a partial disruption of the bacterial association network of unexposed soil. On the other hand, higher values of linear (Kd) and nonlinear (Kf) sorption coefficient in P0 point to the relevance of cation exchange capacity (CEC), clay and organic matter to the capacity of soil to adsorb the herbicide, suggesting that bioavailability was a key factor for the persistence of GP and AMPA. These results contribute to understand the relationship between bacterial taxa exposed to the herbicide, and the importance of soil properties as predictors of the possible rate of degradation and persistence of glyphosate in soil. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Serial ammonia measurement in patients poisoned with glufosinate ammonium herbicide.

    Science.gov (United States)

    Moon, J M; Chun, B J

    2016-05-01

    This study investigated whether ammonia concentrations can predict delayed neurotoxicity development and neurotoxicity latency in glufosinate ammonium (GLA) herbicide-poisoned patients presenting with an alert mental state and stable hemodynamics. This retrospective observational case study included 26 patients divided into 2 groups: neurotoxicity during hospitalization (complicated group) and without neurotoxicity (noncomplicated group). Thirteen patients (50.0%) experienced neurotoxicity at 16 h post-ingestion. Although ammonia concentrations at presentation did not differ significantly between the two groups, the ammonia level in the complicated group increased significantly at the next measurement and remained significantly higher than that in the noncomplicated group until 48 h after ingestion. The peak ammonia concentration before neurotoxicity development was an independent predictor of neurotoxicity (odds ratio: 1.047, 95% confidence interval: 1.010-1.087, p value = 0.014), and the optimal cutoff value of peak ammonia concentration for predicting neurotoxicity was 101.5 μg/dL. The rate of ammonia increase was not associated with the time latency from ingestion to neurotoxicity development. This study showed that serial ammonia measurements in GLA-poisoned patients may identify those who are at high risk of developing neurotoxicity. However, as this study enrolled few patients, further qualified trials are required to confirm our results and to reveal the etiology of hyperammonemia and its causality in neurotoxicity. © The Author(s) 2015.

  6. Aquatic risk assessment of the new rice herbicide profoxydim

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Paloma [Laboratory for Ecotoxicology, Department of the Environment, INIA, Crta De La Coruna Km 7, 28040 Madrid (Spain)]. E-mail: arguello@inia.es; Kubitza, Johanna [BASF-AG, Agricultural Center Limburgerhof, P.O. Box 120, D-67114 Limburgerhof (Germany); Peter Dohmen, G. [BASF-AG, Agricultural Center Limburgerhof, P.O. Box 120, D-67114 Limburgerhof (Germany); Tarazona, Jose V. [Laboratory for Ecotoxicology, Department of the Environment, INIA, Crta De La Coruna Km 7, 28040 Madrid (Spain)

    2006-07-15

    A tiered protocol for assessing ecological risks has been applied to the rice pesticide profoxydim. The initial assessment (Tier I) was based on toxicity exposure ratio (TER) calculations based on laboratory data using a worst-case rice scenario. The first refinement (Tier II) was based on direct toxicity assessment (DTA) of water samples collected during a field-mesocosm study. Finally, a higher-tier assessment on the in situ assessment of paddy community responses (field-mesocosm-Tier III) was performed. A successive application of three pesticides, the herbicides azimsulfuron, propanil and the insecticide malathion, was used as reference controls. The refined assessments indicated a lower risk than that predicted from TER estimations. DTA-based Tier II showed toxicity effects only for concentrations above the recommended dose of profoxydim. Effects for reference controls were observed in DTA which were not expected from Tier I. The field-mesocosm study confirmed these effects but also showed that they were transient and of low relevance. - Risk refinement assessment of rice pesticides starting with DTA and moving to community studies is a cost-effective approach, only if required.

  7. Hydroxyl radical induced transformation of phenylurea herbicides: A theoretical study

    International Nuclear Information System (INIS)

    Mile, Viktória; Harsányi, Ildikó; Kovács, Krisztina; Földes, Tamás; Takács, Erzsébet; Wojnárovits, László

    2017-01-01

    Aromatic ring hydroxylation reactions occurring during radiolysis of aqueous solutions are studied on the example of phenylurea herbicides by Density Functional Theory calculations. The effect of the aqueous media is taken into account by using the Solvation Model Based on Density model. Hydroxyl radical adds to the ring because the activation free energies (0.4–47.2 kJ mol −1 ) are low and also the Gibbs free energies have high negative values ((−27.4) to (−5.9) kJ mol −1 ). According to the calculations in most of cases the ortho- and para-addition is preferred in agreement with the experimental results. In these reactions hydroxycyclohexadienyl type radicals form. In a second type reaction, when loss of chlorine atom takes place, OH/Cl substitution occurs without cyclohexadienyl type intermediate. - Highlights: • Attack of • OH to aniline, phenol, fenuron, monuron, diuron was studied by DFT. • Ortho-para directing is suggested with –NH 2 , –OH and –NHCON(CH 3 ) 2 groups. • • OH addition to the ring gives hydroxycyclohexadienyl radical. • Attack at C-Cl leads to • OH/Cl substitution without cyclohexadienyl intermediate.

  8. Phototransformation of the herbicide sulcotrione on maize cuticular wax.

    Science.gov (United States)

    Ter Halle, Alexandra; Drncova, Daniela; Richard, Claire

    2006-05-01

    Vegetation plays a key role in environmental cycling and the fate of many organic pollutants. This is especially the case for pesticides because plant leaves are their first reaction environment after application. It is commonly accepted that photochemical reactions of pollutants on plants predominantly take place in the cuticular wax coating of the leaves. Thus, we used films made of either cuticular wax extracted from maize or carnauba gray wax as a model support. Under simulated sunlight irradiation, sulcotrione (a new class of triketone herbicides) sorbed on cuticular wax films was photolyzed and mainly underwent an intramolecular cyclization. The photoproduct is a chromone derivative which was isolated and fully characterized. It is reported for the first time as a sulcotrione degradation product. The photoreactivity of formulated sulcotrione at the surface of cuticular waxes was investigated too. It photodegraded more rapidly than nonformulated sulcotrione. This study also shows that the rate of sulcotrione photolysis was much faster than the rate of penetration into the wax; photolysis should be, thus, a relevant process in real conditions.

  9. Correlations between chromatographic parameters and bioactivity predictors of potential herbicides.

    Science.gov (United States)

    Janicka, Małgorzata

    2014-08-01

    Different liquid chromatography techniques, including reversed-phase liquid chromatography on Purosphere RP-18e, IAM.PC.DD2 and Cosmosil Cholester columns and micellar liqud chromatography with a Purosphere RP-8e column and using buffered sodium dodecyl sulfate-acetonitrile as the mobile phase, were applied to study the lipophilic properties of 15 newly synthesized phenoxyacetic and carbamic acid derivatives, which are potential herbicides. Chromatographic lipophilicity descriptors were used to extrapolate log k parameters (log kw and log km) and log k values. Partitioning lipophilicity descriptors, i.e., log P coefficients in an n-octanol-water system, were computed from the molecular structures of the tested compounds. Bioactivity descriptors, including partition coefficients in a water-plant cuticle system and water-human serum albumin and coefficients for human skin partition and permeation were calculated in silico by ACD/ADME software using the linear solvation energy relationship of Abraham. Principal component analysis was applied to describe similarities between various chromatographic and partitioning lipophilicities. Highly significant, predictive linear relationships were found between chromatographic parameters and bioactivity descriptors. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Micellar electrokinetic chromatographic determination of triazine herbicides in water samples.

    Science.gov (United States)

    Li, Zhi; Zhang, Shuaihua; Yin, Xiaofang; Wang, Chun; Wang, Zhi

    2014-09-01

    Dispersive liquid-liquid microextraction combined with online sweeping preconcentration in micellar electrokinetic chromatography was developed for the simultaneous determination of five triazine herbicides (atrazine, simazine, propazine, prometon and simetryn) in water samples. Several experimental parameters affecting the extraction efficiencies such as the type and volume of both the extraction and dispersive solvents, the addition of salt to sample solution, the extraction time and the pH of the sample solution were investigated. Under optimum conditions, the linearity of the method was good in the range from 0.33 to 20 ng mL(-1) for simazine, propazine, atrazine and simetryn, and from 0.17 to 20 ng mL(-1) for prometon, respectively. The sensitivity enrichment factors were in the range from 1750 to 2100, depending on the compound. The limit of detection (S/N = 3) ranged from 0.05 to 0.10 ng mL(-1). The developed method was successfully applied to the analysis of the five triazines in river, ground and well waters. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Seedling Performance Associated with Live or Herbicide Treated Tall Fescue

    Directory of Open Access Journals (Sweden)

    Jonathan J. Halvorson

    2015-01-01

    Full Text Available Tall fescue is an important forage grass which can host systemic fungal endophytes. The association of host grass and endophyte is known to influence herbivore behavior and host plant competition for resources. Establishing legumes into existing tall fescue sods is a desirable means to acquire nitrogen and enhance the nutritive value of forage for livestock production. Competition from existing tall fescue typically must be controlled to ensure interseeding success. We used a soil-on-agar method to determine if soil from intact, living (L, or an herbicide killed (K tall fescue sward influenced germination and seedling growth of three cultivars of tall fescue (E+, MaxQ, and E− or legumes (alfalfa, red clover, and white clover. After 30 days, seedlings were larger and present in greater numbers when grown in L soil rather than K soil. Root growth of legumes (especially white clover and tall fescue (especially MaxQ were not as vigorous in K soil as L soil. While shoot biomass was similar for all cultivars of tall fescue in L soil, MaxQ produced less herbage when grown in K soil. Our data suggest establishing legumes or fescue cultivars may not be improved by first killing the existing fescue sod and seedling performance can exhibit significant interseasonal variation, related only to soil conditions.

  12. Herbicidal potential of ophiobolins produced by Drechslera gigantea.

    Science.gov (United States)

    Evidente, Antonio; Andolfi, Anna; Cimmino, Alessio; Vurro, Maurizio; Fracchiolla, Mariano; Charudattan, Raghavan

    2006-03-08

    Drechslera gigantea, a potential mycoherbicide of grass weeds, was isolated in Florida from naturally infected large crabgrass (Digitaria sanguinalis); it produces phytotoxic metabolites in liquid culture. The main metabolite was identified by spectroscopic methods and optical properties as ophiobolin A (1), a well-known phytotoxic sesterterpene produced by several phytopathogenic fungi of important crops and already extensively studied for its interesting biological activities. The other three minor metabolites proved to be related to ophiobolin A and were identified using the same techniques as 6-epi-ophiobolin A and 3-anhydro-6-epi-ophiobolin A (2 and 3) and ophiobolin I (4). Assayed on punctured detached leaves of several grass and dicotyledon weeds, ophiobolin A proved to be on average more phytotoxic as compared to the other related compounds. Some structural features appear to be important for the phytoxicity, such as the hydroxy group at C-3, the stereochemistry at C-6, and the aldehyde group at C-7. Furthermore, grass weeds usually proved to be more sensitive to the phytotoxins than dicotyledons, on which ophiobolin A caused the appearance of large necrosis even at the lowest concentration assayed. This is the first report about the production of ophiobolins from D. gigantea and of the proposed use as potential natural herbicides against grass weeds.

  13. Surface retention and photochemical reactivity of the diphenylether herbicide oxyfluorfen.

    Science.gov (United States)

    Scrano, Laura; Bufo, Sabino A; Cataldi, Tommaso R I; Albanis, Triantafyllos A

    2004-01-01

    The photochemical behavior of oxyfluorfen [2-chloro-1-(3-etoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene] on two Greek soils was investigated. Soils were sampled from Nea Malgara and Preveza regions, characterized by a different organic matter content. Soils were spiked with the diphenyl-ether herbicide and irradiation experiments were performed either in the laboratory with a solar simulator (xenon lamp) or outside, under natural sunlight irradiation; other soil samples were kept in the dark to control the retention reaction. Kinetic parameters of both retention and photochemical reactions were calculated using zero-, first- and second- (Langmuir-Hinshelwood) order equations, and best fit was checked through statistical analysis. The soil behaviors were qualitatively similar but quantitatively different, with the soil sampled from the Nea Malgara region much more sorbent as compared with Preveza soil. All studied reactions followed second-order kinetics and photochemical reactions were influenced by retaining capability of the soils. The contributions of the photochemical processes to the global dissipation rates were also calculated. Two main metabolites were identified as 2-chloro-1-(3-ethoxy-4-hydroxyphenoxy)-4-(trifluoromethyl)benzene and 2-chloro-1- (3-hydroxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene.

  14. Aquatic risk assessment of the new rice herbicide profoxydim

    International Nuclear Information System (INIS)

    Sanchez, Paloma; Kubitza, Johanna; Peter Dohmen, G.; Tarazona, Jose V.

    2006-01-01

    A tiered protocol for assessing ecological risks has been applied to the rice pesticide profoxydim. The initial assessment (Tier I) was based on toxicity exposure ratio (TER) calculations based on laboratory data using a worst-case rice scenario. The first refinement (Tier II) was based on direct toxicity assessment (DTA) of water samples collected during a field-mesocosm study. Finally, a higher-tier assessment on the in situ assessment of paddy community responses (field-mesocosm-Tier III) was performed. A successive application of three pesticides, the herbicides azimsulfuron, propanil and the insecticide malathion, was used as reference controls. The refined assessments indicated a lower risk than that predicted from TER estimations. DTA-based Tier II showed toxicity effects only for concentrations above the recommended dose of profoxydim. Effects for reference controls were observed in DTA which were not expected from Tier I. The field-mesocosm study confirmed these effects but also showed that they were transient and of low relevance. - Risk refinement assessment of rice pesticides starting with DTA and moving to community studies is a cost-effective approach, only if required

  15. Biomaterials based on photosynthetic membranes as potential sensors for herbicides.

    Science.gov (United States)

    Ventrella, Andrea; Catucci, Lucia; Placido, Tiziana; Longobardi, Francesco; Agostiano, Angela

    2011-08-15

    In this study, ultrathin film multilayers of Photosystem II-enriched photosynthetic membranes (BBY) were prepared and immobilized on quartz substrates by means of a Layer by Layer procedure exploiting electrostatic interactions with poly(ethylenimine) as polyelectrolyte. The biomaterials thus obtained were characterized by means of optical techniques and Atomic Force Microscopy, highlighting the fact that the Layer by Layer approach allowed the BBYs to be immobilized with satisfactory results. The activity of these hybrid materials was evaluated by means of optical assays based on the Hill Reaction, indicating that the biosamples, which preserved about 65% of their original activity even ten weeks after preparation, were both stable and active. Furthermore, an investigation of the biochips' sensitivity to the herbicide terbutryn, as a model analyte, gave interesting results: inhibition of photosynthetic activity was observed at terbutryn concentrations higher than 10(-7)M, thus evidencing the potential of such biomaterials in the environmental biosensor field. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Toxic reactivity of wheat (Triticum aestivum) plants to herbicide isoproturon.

    Science.gov (United States)

    Yin, Xiao Le; Jiang, Lei; Song, Ning Hui; Yang, Hong

    2008-06-25

    The herbicide isoproturon is widely used for controlling weed/grass in agricultural practice. However, the side effect of isoproturon as contaminants on crops is unknown. In this study, we investigated isoproturon-induced oxidative stress in wheat ( Triticum aestivum). The plants were grown in soils with isoproturon at 0-20 mg/kg and showed negative biological responses. The growth of wheat seedlings with isoproturon was inhibited. Chlorophyll content significantly decreased at the low concentration of isoproturon (2 mg/kg), suggesting that chlorophyll was rather sensitive to isoproturon exposure. The level of thiobarbituric acid reactive substances (TBARS), an indicator of cellular peroxidation, showed an increase, indicating oxidative damage to plants. The isoproturon-induced oxidative stress resulted in a substantial change in activities of the majority of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). Activities of the antioxidant enzymes showed a general increase at low isoproturon concentrations and a decrease at high isoproturon concentrations. Activities of CAT in leaves showed progressive suppression under the isoproturon exposure. Analysis of nondenaturing polyacrylamide gel electrophoresis (PAGE) confirmed these results. We also tested the activity of glutathione S-transferase (GST) and observed the activity stimulated by isoproturon at 2-10 mg/kg.

  17. Seleção de genótipos de cana-de-açúcar para acúmulo de protoporfirina ix com uso de herbicidas inibidores da protox Selection of Sugarcane Genotypes for Protoporphyrin IX Accumulation using Protox-Inhibiting Herbicides