WorldWideScience

Sample records for repeated glyphosate applications

  1. Adjuvants for single droplet application of glyphosate

    DEFF Research Database (Denmark)

    Mathiassen, Solvejg Kopp; Kudsk, Per; Lund, Ivar

    2016-01-01

    Retention and biological activity of droplets of glyphosate deposited onto plant leaves using a Drop on Demand inkjet printer application system, was examined on pot-grown Brassica napus, Solanum nigrum, Chenopodium album, Silene noctiflora and Echinocloa crus-galli plants. Retention was measured...... but the biological activity of glyphosate was not improved....

  2. Adjuvants for single droplet application of glyphosate

    DEFF Research Database (Denmark)

    Mathiassen, Solvejg K.; Kudsk, Per; Lund, Ivar

    2016-01-01

    Retention and biological activity of droplets of glyphosate deposited onto plant leaves using a Drop on Demand inkjet printer application system, was examined on pot-grown Brassica napus, Solanum nigrum, Chenopodium album, Silene noctiflora and Echinocloa crus-galli plants. Retention was measured...... but the biological activity of glyphosate was not improved....

  3. Influence of repeated applications of glyphosate on its persistence and soil bioactivity Influência de repetidas aplicações de glifosato na sua persistência e na bioatividade do solo

    Directory of Open Access Journals (Sweden)

    Mara Mercedes de Andréa

    2003-11-01

    Full Text Available Pesticide degradation studies are essential to evaluate its impact in the environment and on non-target organisms. The effect of repeated soil applications of the herbicide glyphosate on its dissipation and on soil microorganisms was studied by radiometric and microbial techniques. Results indicated fast dissipation of the [14C]-glyphosate or [14C]metabolites extractable residues (half-life of 0.92±0.29 month, but increasing half-lives of total mineralization ranging from 2.2 to 3.4 months as the number of applications increased from 1 to 4. No significant correlation was found between 14CO2 production and dehydrogenase activity.Estudos sobre degradação de pesticidas são essenciais à avaliação do impacto que causam no ambiente e em organismos não-alvo. Avaliou-se o efeito de repetidas aplicações do herbicida glifosato em solo na sua dissipação e em microrganismos do solo, por técnicas radiométricas e microbianas. Os resultados indicaram dissipação rápida dos resíduos extraíveis de glifosato marcado com 14C ou de metabólitos contendo 14C (meia-vida de 0,92±0,29 mês, mas meia-vida crescente de 2,2 a 3,4 meses para mineralização total, de acordo com o aumento de 1 a 4 aplicações. Não foi encontrada correlação estatisticamente significativa entre a atividade da desidrogenase e a produção de 14CO2.

  4. Economic assessment of alternatives for glyphosate application in arable farming

    Directory of Open Access Journals (Sweden)

    Kehlenbeck, Hella

    2016-02-01

    Full Text Available Application and sales of herbicides with glyphosate have strongly increased in Germany during the past 10 years. This has raised a number of questions and discussions concerning glyphosate use. Therefore, this paper identifies and evaluates alternatives with an efficacy almost equivalent to glyphosate for different treatmentareas in terms of economic consequences for farms in comparison to glyphosate use by way of example. With the help of exemplary crop rotations uses in arable farming for winter wheat, winter oilseed rape, winter barley, maize and summer barley were analyzed. Within a “worst case scenario” a complete abandonment of glyphosate applications was assumed. Different tillage systems (plough, no-plough were considered. The only alternatives with an efficacy almost equivalent to glyphosate were mechanical measures. For the analyzed treatment-areas (desiccation, pre-sowing, stubble no approved and efficient chemical alternative could be identified. The economic advantages and disadvantages of substituting glyphosate by mechanical alternatives were strongly depending on the treatment-area, the efficacy concerning yield expectations (in comparison to glyphosate use, the tillage system, the necessity of grain drying as well as further operational factors such as the availability of sufficient field work days and mechanical equipment.

  5. Impact of glyphosate resistant corn, glyphosate applications, and tillage on soil nutrient ratios, exoenzyme activities, and nutrient acquisition ratios

    Science.gov (United States)

    We report results of the last two years of a 7-year (2008-2014) field experiment designed to test the null hypothesis that applications of glyphosate on glyphosate resistant corn (Zea mays L.) as a routine weed control practice under both conventional and reduced tillage practices would have no effe...

  6. Water use efficiency by coffee arabica after glyphosate application

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    Felipe Paolinelli de Carvalho

    2014-07-01

    Full Text Available Many coffee growers apply glyphosate in directed applications, but some phytotoxicity has been noted. It is believed some herbicides can exert a direct or indirect negative effect on photosynthesis by reducing the metabolic rate in a way that can affect the water use efficiency. The objective of this study was to investigate the variables related to water use among coffee cultivars subjected to the application of glyphosate and the effects of each dose. The experiment was conducted in a greenhouse using three varieties of coffee (Coffea arabica, Acaiá (MG-6851, Catucaí Amarelo (2SL and Topázio (MG-1190, and three doses of glyphosate (0.0, 115.2 and 460.8 g acid equivalent ha-1, in a factorial 3 x 3 design. At 15 days after application, a reduction in stomatal conductance was observed, and smaller transpiration rate and water use efficiency were found in the fourth leaf at 15 days after application. There was a decrease in the transpiration rate at 45 DAA, with the Acaiá cultivar showing reductions with 115.2 g ha-1. There was transitory reduction in water use efficiency with glyphosate application, but can affect the growth and production. The Acaiá cultivar showed the highest tolerance to glyphosate because the water use efficiency after herbicide application.

  7. Foliar nickel application alleviates detrimental effects of glyphosate drift on yield and seed quality of wheat.

    Science.gov (United States)

    Kutman, Bahar Yildiz; Kutman, Umit Baris; Cakmak, Ismail

    2013-09-04

    Glyphosate drift to nontarget crops causes growth aberrations and yield losses. This herbicide can also interact with divalent nutrients and form poorly soluble complexes. The possibility of using nickel (Ni), an essential divalent metal, for alleviating glyphosate drift damage to wheat was investigated in this study. Effects of Ni applications on various growth parameters, seed yield, and quality of durum wheat ( Triticum durum ) treated with sublethal glyphosate at different developmental stages were investigated in greenhouse experiments. Nickel concentrations of various plant parts and glyphosate-induced shikimate accumulation were measured. Foliar but not soil Ni applications significantly reduced glyphosate injuries including yield losses, stunting, and excessive tillering. Both shoot and grain Ni concentrations were enhanced by foliar Ni treatment. Seed germination and seedling vigor were impaired by glyphosate and improved by foliar Ni application to parental plants. Foliar Ni application appears to have a great potential to ameliorate glyphosate drift injury to wheat.

  8. Impact of glyphosate-resistant corn, glyphosate applications and tillage on soil nutrient ratios, exoenzyme activities and nutrient acquisition ratios.

    Science.gov (United States)

    Jenkins, Michael B; Locke, Martin A; Reddy, Krishna N; McChesney, Daniel S; Steinriede, R Wade

    2017-01-01

    We report results of the last two years of a 7 year field experiment designed to test the null hypothesis: applications of glyphosate on glyphosate-resistant (GR) and non-resistant (non-GR) corn (Zea mays L.) under conventional tillage and no-till would have no effect on soil exoenzymes and microbial activity. Bulk soil (BS) and rhizosphere soil (RS) macronutrient ratios were not affected by either GR or non-GR corn, or glyphosate applications. Differences observed between exoenzyme activities were associated with tillage rather than glyphosate applications. In 2013, nutrient acquisition ratios for bulk and rhizosphere soils indicated P limitations, but sufficient assimilable N. In 2014, P limitations were observed for bulk and rhizosphere soils, in contrast to balanced C and N acquisition ratios in rhizosphere soils. Stoichiometric relationships indicated few differences between glyphosate and non-glyphosate treatments. Negative correlations between C:P and N:P nutrient ratios and nutrient acquisition ratios underscored the inverse relation between soil nutrient status and microbial community exoenzyme activities. Inconsistent relationships between microbial community metabolic activity and exoenzyme activity indicated an ephemeral effect of glyphosate on BS exoenzyme activity. Except for ephemeral effects, glyphosate applications appeared not to affect the function of the BS and RS exoenzymes under conventional tillage or no-till. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  9. Effect of glyphosate application on foliar diseases in glyphosate-tolerant alfalfa

    Science.gov (United States)

    Glyphosate, the active ingredient in Roundup herbicide, inhibits 5-enol-pyruvyl shikimate 3-phophate synthase (EPSPS), an enzyme found in plants, fungi, and bacteria. Plants engineered for glyphosate tolerance with a glyphosate-insensitive EPSPS take up and translocate the herbicide throughout the p...

  10. Impact of seven years of glyphosate resistant corn and glyphosate applications under conventional and reduced tillage on bulk and rhizosphere soil exoenzyme activities and corn root endophytic microbial community structure

    Science.gov (United States)

    Background: Conservation tillage practices across the country have been implementing genetically engineered glyphosate resistant corn crops along with applications of the herbicide glyphosate. We tested the hypothesis that seven years of glyphosate applications to both glyphosate resistant and non-r...

  11. Nodulation and mycorrhization of transgenic soybean after glyphosate application

    Directory of Open Access Journals (Sweden)

    Aloisio Freitas Chagas Junior

    2013-12-01

    Full Text Available The sensitivity of nitrogen-fixing bacteria like Bradyrhizobium spp with in relation to glyphosate can be influenced by the concentration of the herbicide. This study aims to evaluate the effects of two formulations of glyphosate, in two application periods, on nodulation and mycorrhization in a soybean of variety RR P98Y11, using greenhouse, in pots with capacity of 4 L with savanna soils. Six treatments were utilized using Roundup Ultra and Roundup Original with one and two applications, witness without herbicide and witness only with mineral nitrogen, in a completely randomized design. Four evaluations were done, every 15 days, to determine the plant height, shoot and root dry weight, number of nodules, nodule dry weigh and mycorrhizae. It was observed an increase on the number of nodules, with the use of Roundup Ultra until 15 days after the first application. After this period, the witness only with inoculants showed a larger number of nodules. Roundup Ultra had positive influences on the dry weight of nodules, regardless the number of applications. There was no influence of glyphosate formulation considering the mycorrhizal colonization.

  12. Cancer Incidence among Glyphosate-Exposed Pesticide Applicators in the Agricultural Health Study

    OpenAIRE

    De Roos, Anneclaire J.; Blair, Aaron; Rusiecki, Jennifer A.; Hoppin, Jane A.; Svec, Megan; Dosemeci, Mustafa; Sandler, Dale P.; Alavanja, Michael C.

    2004-01-01

    Glyphosate is a broad-spectrum herbicide that is one of the most frequently applied pesticides in the world. Although there has been little consistent evidence of genotoxicity or carcinogenicity from in vitro and animal studies, a few epidemiologic reports have indicated potential health effects of glyphosate. We evaluated associations between glyphosate exposure and cancer incidence in the Agricultural Health Study (AHS), a prospective cohort study of 57,311 licensed pesticide applicators in...

  13. Consequences of phosphate application on glyphosate uptake by roots: Impacts for environmental management practices.

    Science.gov (United States)

    Gomes, Marcelo Pedrosa; Maccario, Sophie; Lucotte, Marc; Labrecque, Michel; Juneau, Philippe

    2015-12-15

    Phosphate (PO4(3-)) fertilization is a common practice in agricultural fields also targets for glyphosate application. Due to their chemical similarities, PO4(3-) and glyphosate compete for soil adsorbing sites, with PO4(3-) fertilization increasing glyphosate bioavailability in the soil solution. After PO4(3-) fertilization, its concentration will be elevated in the soil solution and both PO4(3-) and glyphosate will be readily available for runoff into aquatic ecosystems. In this context, man-made riparian buffer strips (RBS) at the interface of agricultural lands and waterways can be used as a green technology to mitigate water contamination. The plants used in RBS form a barrier to agricultural wastes that can limit runoff, and the ability of these plants to take up these compounds through their roots plays an important role in RBS efficacy. However, the implications of PO4(3-) for glyphosate uptake by roots are not yet clearly demonstrated. Here, we addressed this problem by hydroponically cultivating willow plants in nutrient solutions amended with glyphosate and different concentrations of PO4(3-), assuring full availability of both chemicals to the roots. Using a phosphate carrier inhibitor (phosphonophormic acid-PFA), we found that part of the glyphosate uptake is mediated by PO4(3-) transporters. We observed, however, that PO4(3-) increased glyphosate uptake by roots, an effect that was related to increased root cell membrane stability. Our results indicate that PO4(3-) has an important role in glyphosate physiological effects. Under agricultural conditions, PO4(3-) fertilization can amplify glyphosate efficiency by increasing its uptake by the roots of undesired plants. On the other hand, since simultaneous phosphate and glyphosate runoffs are common, non-target species found near agricultural fields can be affected.

  14. Characterization of bacterial functional groups and microbial activity in microcosms with glyphosate application

    Science.gov (United States)

    Moyano, Sofia; Bonetto, Mariana; Baigorria, Tomas; Pegoraro, Vanesa; Ortiz, Jimena; Faggioli, Valeria; Conde, Belen; Cazorla, Cristian; Boccolini, Monica

    2017-04-01

    Glyphosate is a worldwide used herbicide as c. 90% of transgenic crops are tolerant to it. Microbial degradation of glyphosate molecule in soil is considered the most important process that determines its persistence in the environment. However, the impact of this herbicide on target groups of soil biota remains poorly understood. Our objective was to characterize the abundance of bacterial groups and global microbial activity, under controlled conditions with application of increasing doses of glyphosate. A bioassay was carried out in microcosms using an agricultural soil (Typic Argiudoll) with registered history of glyphosate application from National Institute of Agricultural Technology (INTA, EEA Marcos Juarez, Argentina). Glyphosate of commercial formulation (74.7%) was used and the following treatments were evaluated: Soil without glyphosate (control), and Soil with doses equivalent to 1.12 and 11.2 kg ai ha-1. Microbiological parameters were estimated at 3, 7, 14 and 21 days after herbicide application by counting heterotrophic, cellulolytic, nitrogen fixing (N), and nitrifying bacteria; and fluorescein diacetate hydrolysis (FDA), microbial respiration (MR) and microbial biomass (C-BM). The N cycle related bacteria showed greater sensitivity to glyphosate with significant increases in abundance. On the other hand the C cycle parameters were strongly conditioned by the time elapsed since the application of the herbicide, as did the MR. The FDA declined with the highest dose, while the C-BM was not affected. Therefore, we conclude that in the studied experimental conditions glyphosate stimulated bacterial growth (i.e. target abundances) representing a source of N, C and nutrients. On the other hand, enzymatic activity (FDA) decreased when glyphosate was applied in the highest dose, whereas, it had no effect on the MR nor C-BM, which could be attributable to the organic matter content of the soil. However, future research in field conditions is necessary, for

  15. Aplicação foliar de manganês em soja transgênica tolerante ao glyphosate Foliar application of manganese in transgenic soybean tolerant to glyphosate

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    Claudir José Basso

    2011-10-01

    do suficiente a aplicação do herbicida glifosato não requer a suplementação foliar de manganês em soja geneticamente modificada tolerante a esse herbicida.The yellowing of Roundup Ready soybean after glyphosate application, can be associated to a momentary manganese deficiency. Because of that, with the hypothesis that glyphosate tolerant soybean would need supplementary addition of manganese, the objective of this research was to evaluate different managements in the foliar application of manganese in some soybean parameters. It was developed two experiments, one at Taquaruçú do Sul and other at Boa Vista das Missões, RS in the year of 2009/2010. It was tested the following treatments: 1 without glyphosate application with manual weed control and without manganese foliar application (untreated check; 2 without glyphosate application with manual weed control and one manganese foliar application at 7 days after this manual weed control; 3 with glyphosate application and without manganese foliar application; 4 glyphosate application in mixture with manganese; 5 glyphosate application added of one manganese foliar application at 7 days after glyphosate application; 6 glyphosate application added of manganese foliar application split in two times, at 7 and 14 days after glyphosate application; 7 glyphosate application and one of manganese foliar application at 14 days after glyphosate application. The glyphosate application was realized in the V5 soybean stage, using 720g L-1 i.e, while the used dose of Mn was 2.0L ha-1 of a formulation with 14% (m/v of Mn. There were no significant difference among the treatments to plant height and height insertion of the first legume. The glyphosate application did not affect the absorption and the foliar amount of manganese and nitrogen in soybean crop. Even with the increase in foliar manganese amount, there was no increasing in soybean productivity. This shows that in soils with Mn levels above of the sufficient, it is not

  16. Glyphosate application and direct sowing of winter wheat considering soil cultivation history

    Directory of Open Access Journals (Sweden)

    Nordmeyer, Henning

    2016-02-01

    Full Text Available In a two year field trial (2013/2014 and 2014/2015 the possible impact of glyphosate application on winter wheat after direct sowing was investigated. Glyphosate was applied with single and double application rates seven days before sowing and until five days after sowing. For comparison a mechanical treatment with flat cultivator and rotary harrow was created. The trials were carried out on an agricultural field with plots of three different soil cultivation history (conventional = plough, reduced = mulch sowing, direct sowing = direct sowing with glyphosate application. Plant emergence and yield of winter wheat was investigated. Conventional soil cultivation history showed highest plant emergence and highest yields in both years. Lowest plant emergence was estimated in trials with flat cultivator and reduced or direct sowing soil history. Treatments with glyphosate application before and after sowing showed no significant yield differences. At a double glyphosate application rate, plant emergence was lower in comparison to the single application rate in most cases in 2013/2014. This was also estimated for glyphosate application after sowing in 2014/2015.

  17. Cancer incidence among glyphosate-exposed pesticide applicators in the Agricultural Health Study.

    Science.gov (United States)

    De Roos, Anneclaire J; Blair, Aaron; Rusiecki, Jennifer A; Hoppin, Jane A; Svec, Megan; Dosemeci, Mustafa; Sandler, Dale P; Alavanja, Michael C

    2005-01-01

    Glyphosate is a broad-spectrum herbicide that is one of the most frequently applied pesticides in the world. Although there has been little consistent evidence of genotoxicity or carcinogenicity from in vitro and animal studies, a few epidemiologic reports have indicated potential health effects of glyphosate. We evaluated associations between glyphosate exposure and cancer incidence in the Agricultural Health Study (AHS), a prospective cohort study of 57,311 licensed pesticide applicators in Iowa and North Carolina. Detailed information on pesticide use and other factors was obtained from a self-administered questionnaire completed at time of enrollment (1993-1997). Among private and commercial applicators, 75.5% reported having ever used glyphosate, of which > 97% were men. In this analysis, glyphosate exposure was defined as a) ever personally mixed or applied products containing glyphosate; b) cumulative lifetime days of use, or "cumulative exposure days" (years of use times days/year); and c) intensity-weighted cumulative exposure days (years of use times days/year times estimated intensity level). Poisson regression was used to estimate exposure-response relations between glyphosate and incidence of all cancers combined and 12 relatively common cancer subtypes. Glyphosate exposure was not associated with cancer incidence overall or with most of the cancer subtypes we studied. There was a suggested association with multiple myeloma incidence that should be followed up as more cases occur in the AHS. Given the widespread use of glyphosate, future analyses of the AHS will allow further examination of long-term health effects, including less common cancers.

  18. Effect of glyphosate-boron application on seed composition and nitrogen metabolism in glyphosate-resistant soybean.

    Science.gov (United States)

    Bellaloui, Nacer; Abbas, Hamed K; Gillen, Anne M; Abel, Craig A

    2009-10-14

    The objective of this study was to evaluate the effects of foliar application of glyphosate (Gly) alone, boron (B) alone, and Gly-B combined on seed composition and nitrogen metabolism in glyphosate-resistant soybean (Glycine max (L.) Merr.). No Gly and no B application plants were used as control (C). Results showed that Gly, Gly-B, or B applications increased protein, oleic acid, and total amino acid concentrations in seed. However, oil and linolenic acid concentrations decreased under those treatments compared with the nontreated control. Gly-B combined or B treatments increased B concentration in leaves and seed, nitrate reductase activity (NRA), and nitrogenase activity and resulted in a significant positive correlation between B concentration in leaves and NRA (r = 0.54; P nutrient uptake and translocation may depend on the ion species and form of the nutrient mixed with Gly. These results demonstrate that Gly-B application alters seed composition, nitrogen metabolism, and B status in leaves and seed.

  19. Phosphate fertilizer impacts on glyphosate sorption by soil.

    Science.gov (United States)

    Munira, Sirajum; Farenhorst, Annemieke; Flaten, Don; Grant, Cynthia

    2016-06-01

    This research examined the impact of field-aged phosphate and cadmium (Cd) concentrations, and fresh phosphate co-applications, on glyphosate sorption by soil. Soil samples were collected in 2013 from research plots that had received, from 2002 to 2009, annual applications of mono ammonium phosphate (MAP) at 20, 40 and 80 kg P ha(-1) and from products containing 0.4, 70 or 210 mg Cd kg(-1) as an impurity. A series of batch equilibrium experiments were carried out to quantify the glyphosate sorption distribution constant, Kd. Extractable Cd concentrations in soil had no significant effect on glyphosate sorption. Glyphosate Kd values significantly decreased with increasing Olsen-P concentrations in soil, regardless of the pH conditions studied. Experiments repeated with a commercially available glyphosate formulation showed statistically similar results as the experiments performed with analytical-grade glyphosate. Co-applications of MAP with glyphosate also reduced the available sorption sites to retain glyphosate, but less so when soils already contain large amounts of phosphate. Glyphosate Kd values in soils ranged from 173 to 939 L kg(-1) under very strong to strongly acidic condition but the Kd was always alkaline conditions. The highest Olsen-P concentrations in soil reduced Kd values by 25-44% relative to control soils suggesting that, under moderately acidic to slightly alkaline conditions, glyphosate may become mobile by water in soils with high phosphate levels. Otherwise, glyphosate residues in agricultural soils are more likely to be transported off-site by wind and water-eroded sediments than by leaching or runoff.

  20. Short-term transport of glyphosate with erosion in Chinese loess soil - a flume experiment

    NARCIS (Netherlands)

    Yang, X.; Wang, Fei; Martins Bento, Celia; Xue, Sha; Gai, L.; Dam, van R.C.J.; Mol, J.G.J.; Ritsema, C.J.; Geissen, V.

    2015-01-01

    Repeated applications of glyphosate may contaminate the soil and water and threaten their quality both within the environmental system and beyond it through water erosion related processes and leaching. In this study, we focused on the transport of glyphosate and its metabolite aminomethylphosphonic

  1. Short-term transport of glyphosate with erosion in Chinese loess soil - a flume experiment

    NARCIS (Netherlands)

    Yang, X.; Wang, Fei; Martins Bento, Celia; Xue, Sha; Gai, L.; Dam, van R.C.J.; Mol, J.G.J.; Ritsema, C.J.; Geissen, V.

    2015-01-01

    Repeated applications of glyphosate may contaminate the soil and water and threaten their quality both within the environmental system and beyond it through water erosion related processes and leaching. In this study, we focused on the transport of glyphosate and its metabolite aminomethylphosphonic

  2. Field application of glyphosate induces molecular changes affecting vegetative growth processes in leafy spurge

    Science.gov (United States)

    Recommended rates of glyphosate for non-cultivated areas destroy the aboveground shoots of the perennial plant leafy spurge. However, such applications cause little or no damage to underground adventitious buds (UABs), and thus the plant readily regenerates vegetatively. High concentrations of glyph...

  3. Determination of differences in crop injury from aerial application of glyphosate using vegetation indices and geostatistics

    Science.gov (United States)

    Injury to crops caused by off-target drift of glyphosate can seriously reduce growth and yield, and is of great concern to farmers and aerial applicators. Determining an indirect method for assessing the levels and extent of crop injury could support management decisions. The objectives of this stud...

  4. Final Environmental Assessment of aerial application of glyphosate for control of phragmites on Bear River Migratory Bird Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment (EA) addresses the aerial application of glyphosate to control Phragmites (Phragmites australis) on Bear River Migratory Bird Refuge....

  5. Final Environmental Assessment for Aerial Application of Glyphosate for Control of Phragmites on Bear River Migratory Bird Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment (EA) addresses the aerial application of glyphosate to control Phragmites (Phragmites australis) on Bear River Migratory Bird Refuge....

  6. Seletividade de glyphosate isolado ou em misturas para soja RR em aplicações sequenciais Selectivity of glyphosate alone or in mixtures for RR soybean in sequential applications

    Directory of Open Access Journals (Sweden)

    D.G Alonso

    2013-03-01

    Full Text Available O uso de misturas de herbicidas latifolicidas com o glyphosate tem sido uma alternativa para o controle de plantas daninhas resistentes ao glyphosate ou de difícil controle nos cultivos de soja RR. Este trabalho teve o objetivo de avaliar a seletividade de aplicações sequenciais de glyphosate, isolado ou em mistura com latifolicidas, para a soja RR. As aplicações dos tratamentos foram feitas em plantas de soja cultivar CD214 RR nos estádios de desenvolvimento V1 a V2 e V3 a V4. Os herbicidas e as respectivas doses (g i.a. ha-1 utilizadas foram: glyphosate (g e.a. ha-1 isolado (720/480, 720/720, 960/960 e 1.200/1.200 e as misturas de glyphosate + cloransulam-methyl (720 + 15,12/480 + 15,12, glyphosate + fomesafen (720 + 62,5/480 + 62,5, glyphosate + lactofen (720 + 36/480 + 36, glyphosate + chlorimuron-ethyl (720 + 6,25/480 + 6,25, glyphosate + flumiclorac-pentyl (720 + 15/480 + 15, glyphosate + bentazon (720 + 240/480 + 240 e glyphosate + imazethapyr (720 + 40/480 + 40. O delineamento adotado foi o de blocos casualizados, em esquema de parcelas subdivididas, com quatro repetições. As variáveis avaliadas foram: fitointoxicação, altura de plantas, estande, fechamento do dossel, número de vagens por planta, massa de cem grãos e produtividade. Todos os tratamentos promoveram efeitos visuais de fitointoxicação na cultura da soja; todavia, em nenhuma das situações estudadas houve prejuízo no rendimento de grãos.The use of latifolicide mixed with glyphosate has been an alternative to control weeds resistant to glyphosate or difficult to control in RR soybean crops. The aim of this work was to evaluate the selectivity of sequential applications of glyphosate isolated or in mixture with latifolicide herbicides for RR soybean. Treatment applications were carried out on the soybean cultivar plants CD 214 RR at the developmental stages V1 up to V2 and V3 up to V4. The herbicides and respective rates (g a.i. ha-1 evaluated were: glyphosate

  7. Effects of pig slurry application on soil physical and chemical properties and glyphosate mobility

    Directory of Open Access Journals (Sweden)

    Daniela Aparecida de Oliveira

    2014-10-01

    Full Text Available Pig slurry applied to soil at different rates may affect soil properties and the mobility of chemical compounds within the soil. The purpose of this study was to evaluate the effects of rates of pig slurry application in agricultural areas on soil physical and chemical properties and on the mobility of glyphosate through the soil profile. The study was carried out in the 12th year of an experiment with pig slurry applied at rates of 0 (control, 50, 100 and 200 m³ ha-1 yr-1 on a Latossolo Vermelho distrófico (Hapludox soil. In the control, the quantities of P and K removed by harvested grains were replaced in the next crop cycle. Soil physical properties (bulk density, porosity, texture, and saturated hydraulic conductivity and chemical properties (organic matter, pH, extractable P, and exchangeable K were measured. Soil solution samples were collected at depths of 20, 40 and 80 cm using suction lysimeters, and glyphosate concentrations were measured over a 60-day period after slurry application. Soil physical and chemical properties were little affected by the pig slurry applications, but soil pH was reduced and P levels increased in the surface layers. In turn, K levels were increased in sub-surface layers. Glyphosate concentrations tended to decrease over time but were not affected by pig slurry application. The concentrations of glyphosate found in different depths show that the pratice of this application in agricultural soils has the potential for contamination of groundwater, especially when the water table is the surface and heavy rains occur immediately after application.

  8. Glyphosate in northern ecosystems.

    Science.gov (United States)

    Helander, Marjo; Saloniemi, Irma; Saikkonen, Kari

    2012-10-01

    Glyphosate is the main nonselective, systemic herbicide used against a wide range of weeds. Its worldwide use has expanded because of extensive use of certain agricultural practices such as no-till cropping, and widespread application of glyphosate-resistant genetically modified crops. Glyphosate has a reputation of being nontoxic to animals and rapidly inactivated in soils. However, recent evidence has cast doubts on its safety. Glyphosate may be retained and transported in soils, and there may be cascading effects on nontarget organisms. These processes may be especially detrimental in northern ecosystems because they are characterized by long biologically inactive winters and short growing seasons. In this opinion article, we discuss the potential ecological, environmental and agricultural risks of intensive glyphosate use in boreal regions.

  9. Glyphosate affects seed composition in glyphosate-resistant soybean.

    Science.gov (United States)

    Zobiole, Luiz H S; Oliveira, Rubem S; Visentainer, Jesui V; Kremer, Robert J; Bellaloui, Nacer; Yamada, Tsuioshi

    2010-04-14

    The cultivation of glyphosate-resistant (GR) soybeans has continuously increased worldwide in recent years mainly due to the importance of glyphosate in current weed management systems. However, not much has been done to understand eventual effects of glyphosate application on GR soybean physiology, especially those related to seed composition with potential effects on human health. Two experiments were conducted to evaluate the effects of glyphosate application on GR soybeans compared with its near-isogenic non-GR parental lines. Results of the first experiment showed that glyphosate application resulted in significant decreases in shoot nutrient concentrations, photosynthetic parameters, and biomass production. Similar trends were observed for the second experiment, although glyphosate application significantly altered seed nutrient concentrations and polyunsaturated fatty acid percentages. Glyphosate resulted in significant decreases in polyunsaturated linoleic acid (18:2n-6) (2.3% decrease) and linolenic acid (18:3n-3) (9.6% decrease) and a significant increase in monounsaturated fatty acids 17:1n-7 (30.3% increase) and 18:1n-7 (25% increase). The combined observations of decreased photosynthetic parameters and low nutrient availability in glyphosate-treated plants may explain potential adverse effects of glyphosate in GR soybeans.

  10. Glyphosate no controle de biótipos de azevém e impacto na microbiota do solo Glyphosate application for italian ryegrass biotype control and impact on soil microbiota

    Directory of Open Access Journals (Sweden)

    E.A. Ferreira

    2006-09-01

    second assay evaluated dry matter of the aereal part, plant height, number of leaves and respiration and microbial mass of the soil cultivated with the resistant and sensitive biotypes, with and without glyphosate application (480 g ha-1. At 14 DAA, death of the susceptible biotype was observed, when treated with rates starting from 200 g ha-1 of glyphosate. The resistant ad intermediate resistant biotypes showed glyphosate phytotoxicity of 85% at the highest rate evaluated. The resistant biotype presented the highest dry matter production of the aerial part at 42 DAA and during sprouting, at 72 DAA, compared to the intermediary biotype. The sensitive biotype presented higher plant height, number of leaves and dry mass of the aerial part, to the resistant biotype, without glyphosate. No difference was observed in the microbial activity in the soil among the treatments.

  11. Alteração fisiológica da cana-de-açúcar pela aplicação de Glyphosate e Sulfumeturon-Methyl Physiological alteration in sugarcane influenced by Glyphosate and Sulfumeturon-Methyl application

    Directory of Open Access Journals (Sweden)

    D.K. Meschede

    2011-06-01

    inversamente proporcionais aos níveis Fe. A aplicação de sulfumeturon-methyl não interferiu nos teores de clorofila, no entanto os níveis de carotenoides se mostraram mais sensíveis e seus teores reduzidos. As alterações observadas nos níveis de clorofilas e carotenoides pela aplicação dos produtos podem afetar de maneira distinta o metabolismo da fotossíntese pela absorção e/ou conversão de energia.The partial blockage of the routes of action of herbicides, using low doses, may have important implications by altering the balance of the metabolic processes in plants. Thus, an experiment was conducted in cutting cane ratoon 2 at Cosan Group's Fazenda Jurema in Barra Bonita-SP, during the agricultural years 2006/2007, to verify the effects of glyphosate and sulfometuron methyl sub-doses on the physiological behavior of sugarcane based on the the levels of chlorophyll and carotenoids. The treatments consisted of applications of two herbicides: sulfometuron methyl (480 a.i. kg-1 and glyphosate (360 a.e. kg-1 in different doses and mixtures (Roundup and Curavial, respectively, plus a control treatment, without herbicide application. The doses used were: glyphosate pc ha-1 of 200 mL, 400 mL of glyphosate pc ha-1; pc ha-1 of 200 mL glyphosate + 10 g of pc ha-1 of sulfometuron methyl; pc ha-1 of 150 mL glyphosate + 12 g of pc ha-1 of sulfometuron methyl, sulfometuron methyl pc ha¹ of 20. The experiment was arranged in a randomized block design with four replications. The evaluations were carried out 15 and 30 days after planting (DAP and 30, 60, 90, 120, 150 and 180 days after harvest (DAH. The leaves were cut using the same standardized weight and leaf area. To determine the content of chlorophyll and carotenoids, samples of 0.2 g of fresh leaf tissue were prepared and the extracts were filtered, and spectrophotometer readings were conducted (663 and 645 nm for chlorophyll a and b, respectively. The application of glyphosate and sulfumeturon methyl at larger doses

  12. Glyphosate reduced seed and leaf concentrations of calcium, manganese, magnesium, and iron in non-glyphosate resistant soybean

    OpenAIRE

    ÇAKMAK, İsmail; Cakmak, Ismail; Yazıcı, M. Atilla; YAZICI, M. Atilla; Tutuş, Yusuf; Tutus, Yusuf; ÖZTÜRK, Levent; OZTURK, Levent

    2009-01-01

    Greenhouse experiments were conducted to study the effects of glyphosate drift on plant growth and concentrations of mineral nutrients in leaves and seeds of non-glyphosate resistant soybean plants (Glycine max, L.). Glyphosate was sprayed on plant shoots at increasing rates between 0.06 and 1.2% of the recommended application rate forweed control. In an experiment with 3-week-old plants, increasing application of glyphosate on shoots significantly reduced chlorophyll concentration of the ...

  13. Glyphosate inhibits rust diseases in glyphosate-resistant wheat and soybean.

    Science.gov (United States)

    Feng, Paul C C; Baley, G James; Clinton, William P; Bunkers, Greg J; Alibhai, Murtaza F; Paulitz, Timothy C; Kidwell, Kimberlee K

    2005-11-29

    Glyphosate is a broad-spectrum herbicide used for the control of weeds in glyphosate-resistant crops. Glyphosate inhibits 5-enolpyruvyl shikimate 3-phosphate synthase, a key enzyme in the synthesis of aromatic amino acids in plants, fungi, and bacteria. Studies with glyphosate-resistant wheat have shown that glyphosate provided both preventive and curative activities against Puccinia striiformis f. sp. tritici and Puccinia triticina, which cause stripe and leaf rusts, respectively, in wheat. Growth-chamber studies demonstrated wheat rust control at multiple plant growth stages with a glyphosate spray dose typically recommended for weed control. Rust control was absent in formulation controls without glyphosate, dependent on systemic glyphosate concentrations in leaf tissues, and not mediated through induction of four common systemic acquired resistance genes. A field test with endemic stripe rust inoculum confirmed the activities of glyphosate pre- and postinfestation. Preliminary greenhouse studies also demonstrated that application of glyphosate in glyphosate-resistant soybeans suppressed Asian soybean rust, caused by Phakopsora pachyrhizi.

  14. Selectivity of glyphosate in tank mixtures for RR soybean in sequential applications with mixtures only in the first or second application Seletividade de glyphosate em misturas em tanque para soja RR em aplicações sequenciais com mistura apenas na primeira ou na segunda aplicação

    Directory of Open Access Journals (Sweden)

    D.G Alonso

    2010-12-01

    Full Text Available Tank mixtures among herbicides of different action mechanisms might increase weed control spectrum and may be an important strategy for preventing the development of resistance in RR soybean. However, little is known about the effects of these herbicide combinations on soybean plants. Hence, two experiments were carried out aiming at evaluating the selectivity of glyphosate mixtures with other active ingredients applied in postemergence to RR soybean. The first application was carried out at V1 to V2 soybean stage and the second at V3 to V4 (15 days after the first one. For experiment I, treatments (rates in g ha-1 evaluated were composed by two sequential applications: the first one with glyphosate (720 in tank mixtures with cloransulam (30.24, fomesafen (125, lactofen (72, chlorimuron (12.5, flumiclorac (30, bentazon (480 and imazethapyr (80; the second application consisted of isolated glyphosate (480. In experiment II, treatments also consisted of two sequential applications, but tank mixtures as described above were applied as the second application. The first one in this experiment consisted of isolated glyphosate (720. For both experiments, sequential applications of glyphosate alone at 720/480, 960/480, 1200/480 and 960/720 (Expt. I or 720/480, 720/720, 720/960 and 720/1200 (Expt. II were used as control treatments. Applications of glyphosate tank mixtures with other herbicides are more selective to RR soybean when applied at younger stages whereas applications at later stages might cause yield losses, especially when glyphosate is mixed with lactofen and bentazon.A mistura em tanque entre herbicidas de diferentes mecanismos de ação pode aumentar o espectro de controle dos tratamentos e consistir de uma nova estratégia de controle de plantas daninhas na cultura da soja RR. No entanto, pouco se sabe sobre os efeitos destas misturas nas plantas de soja. Dessa forma, foram realizados dois experimentos com o objetivo de avaliar a

  15. The history and current status of glyphosate.

    Science.gov (United States)

    Duke, Stephen O

    2017-06-23

    Glyphosate is the only herbicide to target the enzyme 5-enolpyruvyl-3-shikimate phosphate synthase (EPSPS). It is a high use rate, non-selective herbicide that translocates primarily to metabolic sinks, killing meristematic tissues away from the application site. Its phloem-mobile properties and slow action in killing weeds allow the herbicide to move throughout the plant to kill all meristems, making it effective for perennial weed control. Since commercialization in 1974, its use has grown to dominate the herbicide market. Much of its use is on transgenic, glyphosate-resistant crops (GRCs), which have been the dominant transgenic crops worldwide. GRCs with glyphosate provided the most effective and inexpensive weed management technology in history for a decade or more. However, as a consequence of the rapid increase in glyphosate-resistant (GR) weeds, the effectiveness of glyphosate use in GRCs is declining. Critics have claimed that glyphosate-treated GRCs have altered mineral nutrition and increased susceptibility to plant pathogens because of glyphosate's ability to chelate divalent metal cations, but the complete resistance of GRCs to glyphosate indicates that chelating metal cations do not contribute to the herbicidal activity or significantly affect mineral nutrition. The rates of increases in yields of maize, soybean, and cotton in the USA have been unchanged after high adoption rates of GRCs. Glyphosate is toxic to some plant pathogens, and thereby can act as a fungicide in GRCs. Ultra-low doses of glyphosate stimulate plant growth in glyphosate-susceptible plants by unknown mechanisms. Despite rapid and widespread increases in GR weeds, glyphosate use has not decreased. However, as GR weeds increase, adoption of alternative technologies will eventually lead to decreased use. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Published 2017. This article is a U.S. Government work and is in the public domain in

  16. Utilização de glifosato para o controle de ferrugem da soja Glyphosate application on soybean rust control

    Directory of Open Access Journals (Sweden)

    Rafael Moreira Soares

    2008-04-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de glifosato sobre a germinação de esporos de Phakopsora pachyrhizi e no controle da ferrugem da soja, aplicado preventiva e erradicativamente, em condições controladas. A germinação de esporos foi avaliada tendo-se vertido, em meio de cultura, soluções de esporos com diferentes concentrações do glifosato (0, 100, 1.000, 10.000 e 20.000 ppm e fungicidas. Para avaliar o controle da ferrugem, plantas foram pulverizadas com glifosato, com variação da dose e do momento, tendo-se medido a severidade da doença. Houve efeito do produto sobre os esporos do fungo, o que reduziu sua germinação. As pulverizações em plantas, em casa de vegetação, mostraram um efeito do produto sobre a ferrugem, quando aplicado preventivamente, porém com período de proteção curto e fungitoxicidade inferior à do fungicida tebuconazole. O uso do glifosato, avaliado nesse ensaio, não deve ser visto como medida de manejo de ferrugem, e não interfere nas práticas habituais de controle da ferrugem da soja.The objective of this work was to evaluate the effect of glyphosate on the germination of Phakopsora pachyrhizi spores, and on soybean rust control; applications were either preventive or eradicative under controlled conditions. The germination of spores was evaluated by pouring spores solutions on culture medium, with different concentrations of glyphosate (0, 100, 1,000, 10,000 and 20,000 ppm and fungicides. For the rust control evaluation, plants were sprayed with glyphosate, varying doses and moments, and estimating the disease severity. The product reduced spores germination. Plants sprayed in greenhouse conditions, showed effect of the product on rust, when applied preventively, but with short protection period and lower fungus toxicity than tebuconazole fungicide. The use of glyphosate, evaluated in this trial, must not be taken as a rust management measure, and should not interfere in usual

  17. Glyphosate-Resistant and Conventional Canola (Brassica napus L.) Responses to Glyphosate and Aminomethylphosphonic Acid (AMPA) Treatment.

    Science.gov (United States)

    Corrêa, Elza Alves; Dayan, Franck E; Owens, Daniel K; Rimando, Agnes M; Duke, Stephen O

    2016-05-11

    Glyphosate-resistant (GR) canola contains two transgenes that impart resistance to the herbicide glyphosate: (1) the microbial glyphosate oxidase gene (gox) encoding the glyphosate oxidase enzyme (GOX) that metabolizes glyphosate to aminomethylphosphonic acid (AMPA) and (2) cp4 that encodes a GR form of the glyphosate target enzyme 5-enolpyruvylshikimic acid-3-phosphate synthase. The objectives of this research were to determine the phytotoxicity of AMPA to canola, the relative metabolism of glyphosate to AMPA in GR and conventional non-GR (NGR) canola, and AMPA pool sizes in glyphosate-treated GR canola. AMPA applied at 1.0 kg ha(-1) was not phytotoxic to GR or NGR. At this AMPA application rate, NGR canola accumulated a higher concentration of AMPA in its tissues than GR canola. At rates of 1 and 3.33 kg ae ha(-1) of glyphosate, GR canola growth was stimulated. This stimulatory effect is similar to that of much lower doses of glyphosate on NGR canola. Both shikimate and AMPA accumulated in tissues of these glyphosate-treated plants. In a separate experiment in which young GR and NGR canola plants were treated with non-phytotoxic levels of [(14)C]-glyphosate, very little glyphosate was metabolized in NGR plants, whereas most of the glyphosate was metabolized to AMPA in GR plants at 7 days after application. Untreated leaves of GR plants accumulated only metabolites (mostly AMPA) of glyphosate, indicating that GOX activity is very high in the youngest leaves. These data indicate that more glyphosate is transformed to AMPA rapidly in GR canola and that the accumulated AMPA is not toxic to the canola plant.

  18. Effects of Formulated Glyphosate and Adjuvant Tank Mixes on Atomization from Aerial Application Flat Fan Nozzles

    Science.gov (United States)

    2012-01-01

    flat fans, hollow cones , straight streams, air induction, and electrostatic nozzles. Additionally, nozzles, such as rotary atomizers, may introduce...imparted by the airstream, they will shatter [24,25]. When the for- mulated glyphosate product had additional adjuvants added, the changes (ei- ther increase...Experimental Study of Drop Size Distribution in the Bag Breakup Regime,” Ind. Eng. Chem. Res., Vol. 50, No. 16, 2011, 9767–9773. [25] Lane, W. R., “ Shatter of

  19. Glyphosate accumulation, translocation, and biological effects in Coffea arabica after single and multiple exposures

    DEFF Research Database (Denmark)

    Schrübbers, Lars Christoph; Valverde, Bernal E.; Strobel, Bjarne W.

    2016-01-01

    In perennial crops like coffee, glyphosate drift exposure can occur multiple times during its commercial life span. Due to limited glyphosate degradation in higher plants, a potential accumulation of glyphosate could lead to increased biological effects with increased exposure frequency....... In this study, we investigated glyphosate translocation over time, and its concentration and biological effects after single and multiple simulated spray-drift exposures. Additionally, shikimic acid/glyphosate ratios were used as biomarkers for glyphosate binding to its target enzyme.Four weeks after...... the exposure, glyphosate was continuously translocated. Shikimic acid levels were lin-ear correlated with glyphosate levels. After two months, however, glyphosate appeared to have reduced activity. In the greenhouse, multiple applications resulted in higher internal glyphosate concentrations.The time...

  20. Co-expression of G2-EPSPS and glyphosate acetyltransferase GAT genes conferring high tolerance to glyphosate in soybean

    Directory of Open Access Journals (Sweden)

    Bingfu eGuo

    2015-10-01

    Full Text Available Glyphosate is a widely used non-selective herbicide with broad spectrum of weed control around the world. At present, most of the commercial glyphosate tolerant soybeans utilize glyphosate tolerant gene CP4-EPSPS or glyphosate acetyltransferase gene GAT separately. In this study, both glyphosate tolerant gene G2-EPSPS and glyphosate degraded gene GAT were co-transferred into soybean and transgenic plants showed high tolerance to glyphosate. Molecular analysis including PCR, Sothern blot, qRT-PCR and Western blot revealed that target genes have been integrated into genome and expressed effectively at both mRNA and protein levels. Furthermore, the glyphosate tolerance analysis showed that no typical symptom was observed when compared with a glyphosate tolerant line HJ06-698 derived from GR1 transgenic soybean even at four-fold labeled rate of Roundup. Chlorophyll and shikimic acid content analysis of transgenic plant also revealed that these two indexes were not significantly altered after glyphosate application. These results indicated that co-expression of G2-EPSPS and GAT conferred high tolerance to the herbicide glyphosate in soybean. Therefore, combination of tolerant and degraded genes provides a new strategy for developing glyphosate tolerant transgenic crops.

  1. The control of Asian rust by glyphosate in glyphosate-resistant soybeans.

    Science.gov (United States)

    Feng, Paul C C; Clark, Celeste; Andrade, Gabriella C; Balbi, Maria C; Caldwell, Pat

    2008-04-01

    Glyphosate is a widely used broad-spectrum herbicide. Recent studies in glyphosate-resistant (GR) crops have shown that, in addition to its herbicidal activity, glyphosate exhibits activity against fungi, thereby providing disease control benefits. In GR wheat, glyphosate has shown both preventive and curative activities against Puccinia striiformis f. sp. tritici (Erikss) CO Johnston and Puccinia triticina Erikss, which cause stripe and leaf rusts respectively. Laboratory studies confirmed earlier observations that glyphosate has activity against Phakopsora pachyrhizi Syd & P Syd which causes Asian soybean rust (ASR) in GR soybeans. The results showed that glyphosate at rates between 0.84 and 1.68 kg ha(-1) delayed the onset of ASR in GR soybeans. However, field trials conducted in Argentina and Brazil under natural infestations showed variable ASR control from application of glyphosate in GR soybeans. Further field studies are ongoing to define the activity of glyphosate against ASR. These results demonstrate the disease control activities of glyphosate against rust diseases in GR wheat and GR soybeans. Copyright (c) 2007 Society of Chemical Industry.

  2. Influência da aplicação de glyphosate na queda de frutos e de folhas de coqueiros Influence of glyphosate application on coconut fruit and leaf drop

    Directory of Open Access Journals (Sweden)

    S.O. Procopio

    2009-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a queda de frutos e de folhas de coqueiros após a aplicação do herbicida glyphosate. O experimento foi instalado no município de Neópolis-SE, no período de agosto a setembro de 2007. O coqueiral da variedade Anão-Verde foi implantado há 11 anos, em área sob sistema de irrigação por microaspersão. O delineamento experimental foi o inteiramente casualizado, com cinco repetições, em esquema fatorial 3 x 3 + 1, sendo três doses do herbicida glyphosate (3,4; 6,8; e 13,6 g por planta, três formas de aplicação (produto aplicado apenas no estipe, da base a 1 m de altura; produto aplicado apenas no solo ao redor da copa, dentro de um raio de 2 m na zona de coroamento; e, ainda, a combinação das duas formas de aplicação, mais um tratamento adicional de controle sem aplicação. Durante quatro semanas, aos 7, 14, 21 e 28 dias após a aplicação dos tratamentos (DAA, realizou-se a contagem dos frutos caídos dos cachos de números 11, 12, 13, 14, 15, 16, 17, 18 e 19 e das folhas caídas. Aos 35 DAA, realizou-se a contagem dos frutos dos cachos 18 e 19 que possuíam valor comercial. Até os 28 DAA, o herbicida glyphosate não influenciou a queda de frutos e de folhas, independentemente da forma de aplicação, não havendo efeito desse herbicida sobre o número de frutos comerciais da colheita seguinte à aplicação.The objective of this work was to evaluate coconut fruit and leaf drop after glyphosate application. The experiment was carried out in Neopolis, Sergipe from August to September 2007. The experimental area was composed by 11-year-old coconut plants of the variety green-dwarf, irrigated with micro-sprinklers. The experiment was arranged in a completely randomized design with five replicates, and the treatments were arranged in a 3 x 3 + 1 factorial scheme, with three herbicide doses (3,4; 6,8; and 13,6 g per plant, three modes of herbicide application (on the trunk, from the base up to

  3. Estabelecimento de condições operacionais para o bico rotativo micromax na aplicação do herbicida glyphosate Establishment of operational conditions for micromax rotary atomizers in the application of glyphosate

    Directory of Open Access Journals (Sweden)

    P. C. R. Oliveira

    1984-01-01

    Full Text Available Alguns parâmetros operaciona is do bico rotativo Micromax para apli cação do herbi cida glypho sate foram estudados em condições de laboratório. O bico Micromax a 1.600 rpm e vazão de 0,96 //min forneceu gotas com vmd de 280 μm e à vazão de 0,43 i/min , de 232 μm, sendo que em ambas as condições o coeficient e de dispersão (r = vmd/nmd foi inferior a 1,4, atendendo, portanto, às especificações para o processo CDA. A distância entre bicos a serem montadas numa barra foi determinada em mesa de estudo do padrão de deposição foi de 1,80 m para a vazão de 0,96 Z/min e concentração da formulação comercial do glyphosate entre 4% e 6%. Essa distancia foi de 1,40 m para vazão de 0,43 1/min e concentração de glyphosate entre 9% e 13%. Distancias fora dessas especificações produziram deposições bastante irregulares sob a barra de pulverização.Some operation al parameters of Micromax rotary atomizers in the application of glyphosate were studied under laboratory conditions. Micromax nozzle at 1.600 rpm and 0,96 1/min feed rate produced 280m vmd droplets and 0,43 1/min feed rate, produ ced 232 m vmd droplets. In both conditions the dispersion coefficien t (r = vmd/nmd was bellow 1,4, attending to the spedfication for CDA. Nozzl espacement between Micromax heads in a spray boom was estab lished as 1,80 m for 0,96 1/min feed rate using 4% to 6% glyphosate (commercia l solution and 1,40 m for 0,43 Z/min feed rate using 9% to 13% solution. Nozzle spacement out of these specifications produces very irregular deposition patterns.

  4. Glyphosate residues in rural groundwater, Nottawasaga River Watershed, Ontario, Canada.

    Science.gov (United States)

    Van Stempvoort, Dale R; Spoelstra, John; Senger, Natalie D; Brown, Susan J; Post, Ryan; Struger, John

    2016-10-01

    The objective of this study was to investigate the occurrence of glyphosate residues (glyphosate and its metabolite AMPA) in shallow groundwater in a catchment dominated by agriculture, and to examine the potential for this groundwater to store and transmit these compounds to surface waters. Glyphosate residues were found in some of the groundwater samples collected in riparian (surface seeps), upland (mostly glyphosate and AMPA were detected in 10.5 and 5.0%, respectively, of the groundwater samples analyzed as part of this study. All concentrations of glyphosate were well below Canadian guidelines for drinking water quality and for protection of aquatic life. Seasonal differences in concentrations in riparian seeps were possibly related to cycles of weather, herbicide application and degradation of glyphosate. Highest concentrations were at upland sites (663 ng L(-1) of glyphosate, 698 ng L(-1) of AMPA), apparently related to localized applications. Most glyphosate detections in wetlands were >0.5 km distant from possible areas of application, and, combined with other factors, suggest an atmospheric transport and deposition delivery mechanism. In both upland and wetland settings, highest glyphosate concentrations were sometimes not at the shallowest depths, indicating influence of hydrological factors. The glyphosate/AMPA detections in riparian seeps demonstrated that these compounds are persistent enough to allow groundwater to store and transmit glyphosate residues to surface waters. Detections in the wetlands support earlier evidence that atmospheric transport and deposition may lead to glyphosate contamination of environments not intended as targets of applications. This interpretation is further supported by detections of both glyphosate and AMPA in precipitation samples collected in the same watershed. © 2016 Her Majesty the Queen in Right of Canada Pest Management Science © 2016 Society of Chemical Industry. © 2016 Her Majesty the Queen in Right of

  5. Glyphosate-resistant and -susceptible soybean (Glycine max) and canola (Brassica napus) dose response and metabolism relationships with glyphosate.

    Science.gov (United States)

    Nandula, Vijay K; Reddy, Krishna N; Rimando, Agnes M; Duke, Stephen O; Poston, Daniel H

    2007-05-02

    Experiments were conducted to determine (1) dose response of glyphosate-resistant (GR) and -susceptible (non-GR) soybean [Glycine max (L.) Merr.] and canola (Brassica napus L.) to glyphosate, (2) if differential metabolism of glyphosate to aminomethyl phosphonic acid (AMPA) is the underlying mechanism for differential resistance to glyphosate among GR soybean varieties, and (3) the extent of metabolism of glyphosate to AMPA in GR canola and to correlate metabolism to injury from AMPA. GR50 (glyphosate dose required to cause a 50% reduction in plant dry weight) values for GR (Asgrow 4603RR) and non-GR (HBKC 5025) soybean were 22.8 kg ae ha-1 and 0.47 kg ha-1, respectively, with GR soybean exhibiting a 49-fold level of resistance to glyphosate as compared to non-GR soybean. Differential reduction in chlorophyll by glyphosate was observed between GR soybean varieties, but there were no differences in shoot fresh weight reduction. No significant differences were found between GR varieties in metabolism of glyphosate to AMPA, and in shikimate levels. These results indicate that GR soybean varieties were able to outgrow the initial injury from glyphosate, which was previously caused at least in part by AMPA. GR50 values for GR (Hyola 514RR) and non-GR (Hyola 440) canola were 14.1 and 0.30 kg ha-1, respectively, with GR canola exhibiting a 47-fold level of resistance to glyphosate when compared to non-GR canola. Glyphosate did not cause reduction in chlorophyll content and shoot fresh weight in GR canola, unlike GR soybean. Less glyphosate (per unit leaf weight) was recovered in glyphosate-treated GR canola as compared to glyphosate-treated GR soybean. External application of AMPA caused similar injury in both GR and non-GR canola. The presence of a bacterial glyphosate oxidoreductase gene in GR canola contributes to breakdown of glyphosate to AMPA. However, the AMPA from glyphosate breakdown could have been metabolized to nonphytotoxic metabolites before causing injury

  6. Influence of glyphosate, crop volunteer and root pathogens on glyphosate-resistant wheat under controlled environmental conditions.

    Science.gov (United States)

    Baley, George J; Campbell, Kimberley G; Yenish, Joseph; Kidwell, Kimberlee K; Paulitz, Timothy C

    2009-03-01

    The herbicide glyphosate has a synergistic effect on root disease because of increased susceptibility from reduced plant defenses resulting from the blockage of the shikimic acid pathway. Could glyphosate-resistant (GR) wheat cultivars and glyphosate application in-crop increase the risk of damage from soil-borne pathogens? Growth chamber experiments were conducted with two GR wheat lines and their corresponding glyphosate-sensitive (GS) parents and four pathogens (Rhizoctonia solani Kühn R. oryzae Ryker & Gooch, Gaeumannomyces graminis (Sacc.) v. Arx & J. Olivier var. tritici J. Walker and Pythium ultimum Trow). Treatments consisted of different herbicide timings and planting of crop volunteer to mimic management practices in the field. GR cultivars were not inherently more susceptible to root pathogens than GS cultivars, and application of glyphosate did not increase root disease. When crop volunteer was grown in close proximity to GR cultivars, the timing of glyphosate application had a profound effect. In general, the longer the crop volunteer was left before killing with glyphosate, the greater was the competitive effect on the planted crop. Both R. solani and G. graminis var. tritici reduced plant height, number of tillers and root length of the GR cultivars in the presence of crop volunteer with glyphosate application. To minimize the damaging effects of these pathogens, producers should apply glyphosate at least 2-3 weeks before planting GR wheat, as currently advised for GS cereals. 2008 Society of Chemical Industry.

  7. Persistence of glyphosate and aminomethylphosphonic acid in loess soil under different combinations of temperature, soil moisture and light/darkness.

    Science.gov (United States)

    Bento, Célia P M; Yang, Xiaomei; Gort, Gerrit; Xue, Sha; van Dam, Ruud; Zomer, Paul; Mol, Hans G J; Ritsema, Coen J; Geissen, Violette

    2016-12-01

    The dissipation kinetics of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) were studied in loess soil, under biotic and abiotic conditions, as affected by temperature, soil moisture (SM) and light/darkness. Nonsterile and sterile soil samples were spiked with 16mgkg(-1) of glyphosate, subjected to three SM contents (20% WHC, 60% WHC, saturation), and incubated for 30days at 5°C and 30°C, under dark and light regimes. Glyphosate and AMPA dissipation kinetics were fit to single-first-order (SFO) or first-order-multicompartment (FOMC) models, per treatment combination. AMPA kinetic model included both the formation and decline phases. Glyphosate dissipation kinetics followed SFO at 5°C, but FOMC at 30°C. AMPA followed SFO dissipation kinetics for all treatments. Glyphosate and AMPA dissipation occurred mostly by microbial activity. Abiotic processes played a negligible role for both compounds. Under biotic conditions, glyphosate dissipation and AMPA formation/dissipation were primarily affected by temperature, but also by SM. Light regimes didn't play a significant role. Glyphosate DT50 varied between 1.5 and 53.5days, while its DT90 varied between 8.0 and 280days, depending on the treatment. AMPA persisted longer in soil than glyphosate, with its DT50 at 30°C ranging between 26.4 and 44.5days, and its DT90 between 87.8 and 148days. The shortest DT50/DT90 values for both compounds occurred at 30°C and under optimal/saturated moisture conditions, while the largest occurred at 5°C and reaching drought stress conditions. Based on these results, we conclude that glyphosate and AMPA dissipate rapidly under warm and rainy climate conditions. However, repeated glyphosate applications in fallows or winter crops in countries where cold and dry winters normally occur could lead to on-site soil pollution, with consequent potential risks to the environment and human health. To our knowledge, this study is the first evaluating the combined effect of

  8. Differential response of two sourgrass populations to glyphosate

    Directory of Open Access Journals (Sweden)

    São Paulo State University, Jaboticabal, SP, Brazil

    2013-02-01

    Full Text Available The repetitive use of glyphosate may cause increase on the resistance of sourgrass (Digitaria insularis through mechanisms of natural selection. The aim of this study was to verify the response of two populations of sourgrass (one collected from nonagricultural area and the other one from area suspected of glyphosate resistance to increasing doses of glyphosate. The experimental design was completely randomized with four repetitions. For both populations, glyphosate was sprayed at 10 doses (0D, D/16, D/8, D/4, D/2, D, 2D, 4D, 8D, and 16D; so that D is the dose of 1.08 kg e.a. ha-1. The treatments were sprayed when the plants had shown 3-5 tillers. The population collected in the nonagricultural area was slightly more sensible to the herbicide glyphosate than the population originated from an area where the herbicide application is common, not indicating glyphosate resistance.

  9. Determination of glyphosate and aminomethylphosphonic acid in aqueous soil matrices: a critical analysis of the 9-fluorenylmethyl chloroformate derivatization reaction and application to adsorption studies.

    Science.gov (United States)

    Báez, María E; Fuentes, Edwar; Espina, María José; Espinoza, Jeannette

    2014-11-01

    The assessment of the environmental fate of glyphosate and its degradation product (aminomethylphosphonic acid) is of great interest given the widespread use of the herbicide. Studies of adsorption-desorption and transport processes in soils require analytical methods with sensitivity, accuracy, and precision suitable for determining the analytes in aqueous equilibrium solutions of varied complexity. In this work, the effect of factors on the yield of the derivatization of both compounds with 9-fluorenylmethyl chloroformate for applying in aqueous solutions derived from soils was evaluated through factorial experimental designs. Interference effects coming from background electrolytes and soil matrices were established. The whole method had a linear response up to 640 ng/mL (R(2) > 0.999) under optimized conditions for high-performance liquid chromatography with fluorescence detection. Limits of detection were 0.6 and 0.4 ng/mL for glyphosate and aminomethylphosphonic acid, respectively. The relative standard deviation was 4.4% for glyphosate (20 ng/mL) and 5.9% for aminomethylphosphonic acid (10 ng/mL). Adsorption of compounds on four different soils was assessed. Isotherm data fitted well the Freundlich model (R(2) > 0.97). Kf constants varied between 93 ± 3.1 and 2045 ± 157 for glyphosate and between 99 ± 4.1 and 1517 ± 56 (μg(1-1/) (n)  mL(1/) (n) ( ) g(-1) ) for aminomethylphosphonic acid, showing the broad range of applicability of the proposed method.

  10. Leaching of Glyphosate and Aminomethylphosphonic Acid from an Agricultural Field over a Twelve-Year Period

    DEFF Research Database (Denmark)

    Norgaard, Trine; Moldrup, Per; Ferré, Ty P A

    2014-01-01

    The globally-used herbicide glyphosate (N-(phosphonomethyl)glycine) and its most frequently detected metabolite, aminomethylphosphonic acid (AMPA), were studied in a unique 12-year field-scale monitoring program. The leaching of glyphosate, AMPA, and soil particles were studied in a shallow...... intensity and the timing of rain events after glyphosate application....

  11. Avaliação do uso de glyphosate em soja geneticamente modificada e sua relação com o ácido chiquímico Evaluation of glyphosate application on transgenic soybean and its relationship with shikimic acid

    Directory of Open Access Journals (Sweden)

    D.A.S. Franco

    2012-09-01

    plantas de soja transgênica no campo quando tratadas de forma isolada com glyphosate. Os resultados também mostraram exsudação radicular do glyphosate por soja transgênica, com posterior absorção por soja convencional. Foram detectados resíduos de glyphosate e ácido aminometilfosfônico na solução nutritiva.Glyphosate [N-(phosphonomethyl glycine]-resistant crops (GRC are the transgenic crops most extensively grown worldwide, with soybean being the major GRC. It is important to evaluate the impact of glyphosate on transgenic soybean and its relationship with shikimic acid. A field experiment was conducted at Engenheiro Coelho-SP, Brazil, during the agricultural year 2007/2008 to evaluate the effect of glyphosate on the growth, development, and seed quality of GRC soybean variety BRS Valiosa RR. A randomized block design was used with four replications. Glyphosate was applied at 720 and 960 g a.e. ha-1 (acid equivalent and in sequence at the doses 720/720, 960/720, and 960/720/720 g a.e. ha-1 (acid equivalent. To evaluate transfer from GRC soybean to non GRC soybean cultivated in nutrient solution, a pot experiment was conducted at Instituto Biológico, SP, Brazil. Glyphosate was applied on the GRC soybean (M8045RR at 2,400 g a.e. ha-1. Both GRC soybean and non GRC soybean were sown in the same box with nutrient solution. At 0, 1, 3, 7, and 10 days after application, shikimic acid was measured by HPLC and the glyphosate and aminomethylphosphonic acid (AMPA levels in nutrient solution were determined by GC-MS. The results showed that yield, plant height, seed oil, and protein contents were not affected by glyphosate application. GRC soybean accumulated shikimic acid in the field. Glyphosate and AMPA were released through the roots of GRC soybean, and subsequently taken up by non-GRC soybean, exerting inhibitory effects on their shikimic pathway.

  12. Glyphosate persistence in seawater.

    Science.gov (United States)

    Mercurio, Philip; Flores, Florita; Mueller, Jochen F; Carter, Steve; Negri, Andrew P

    2014-08-30

    Glyphosate is one of the most widely applied herbicides globally but its persistence in seawater has not been reported. Here we quantify the biodegradation of glyphosate using standard "simulation" flask tests with native bacterial populations and coastal seawater from the Great Barrier Reef. The half-life for glyphosate at 25 °C in low-light was 47 days, extending to 267 days in the dark at 25 °C and 315 days in the dark at 31 °C, which is the longest persistence reported for this herbicide. AMPA, the microbial transformation product of glyphosate, was detected under all conditions, confirming that degradation was mediated by the native microbial community. This study demonstrates glyphosate is moderately persistent in the marine water under low light conditions and is highly persistent in the dark. Little degradation would be expected during flood plumes in the tropics, which could potentially deliver dissolved and sediment-bound glyphosate far from shore.

  13. 草甘膦使用与生态环境%Application and Ecological Environment of Glyphosate

    Institute of Scientific and Technical Information of China (English)

    苏少泉

    2011-01-01

    Since the commercialization of glyphosate-resistant crop in 1996, their total area had increased rapidly, and the gyphosate was widely used. This paper reviewed the influence of glyphosate on ecological environment.%从抗草甘膦作物1996年商品化种植以来,其种植面积迅速扩大,而草甘膦也得到广泛应用.评述了草甘膦对生态环境的影响.

  14. Effects of glyphosate on the mineral content of glyphosate-resistant soybeans (Glycine max).

    Science.gov (United States)

    Duke, Stephen O; Reddy, Krishna N; Bu, Kaixuan; Cizdziel, James V

    2012-07-11

    There are conflicting claims as to whether treatment with glyphosate adversely affects mineral nutrition of glyphosate-resistant (GR) crops. Those who have made claims of adverse effects have argued links between reduced Mn and diseases in these crops. This article describes experiments designed to determine the effects of a recommended rate (0.86 kg ha(-1)) of glyphosate applied once or twice on the mineral content of young and mature leaves, as well as in seeds produced by GR soybeans (Glycine max) in both the greenhouse and field using inductively coupled plasma mass spectrometry (ICP-MS). In the greenhouse, there were no effects of either one application (at 3 weeks after planting, WAP) or two applications (at 3 and 6 WAP) of glyphosate on Ca, Mg, Mn, Zn, Fe, Cu, Sr, Ba, Al, Cd, Cr, Co, or Ni content of young or old leaves sampled at 6, 9, and 12 WAP and in harvested seed. Se concentrations were too low for accurate detection in leaves, but there was also no effect of glyphosate applications on Se in the seeds. In the field study, there were no effects of two applications (at 3 and 6 WAP) of glyphosate on Ca, Mg, Mn, Zn, Fe, Cu, Sr, Ba, Al, Cd, Cr, Co, or Ni content of young or old leaves at either 9 or 12 WAP. There was also no effect on Se in the seeds. There was no difference in yield between control and glyphosate-treated GR soybeans in the field. The results indicate that glyphosate does not influence mineral nutrition of GR soybean at recommended rates for weed management in the field. Furthermore, the field studies confirm the results of greenhouse studies.

  15. Dissipation of glyphosate from grapevine soils in Sonora, Mexico

    Directory of Open Access Journals (Sweden)

    Norma J. Salazar López

    2016-10-01

    Full Text Available Grapevine is one of the important crops in Sonora, due to revenue generation from its export to foreign countries. Among the most widely used herbicides for this crop is glyphosate, which is considered moderately toxic and persistent. The present research evaluates the dissipation of glyphosate in grapevine planted soil at three depths (5, 30 and 60 cm. Sampling was carried out before glyphosate application, and 5, 10, 18, 27, and 65 days after. Glyphosate was extracted from soil samples using ammonium hydroxide. The derivate extracts were partitioned with dichloromethane and analyzed using gas chromatography with pulsed flame photometric detector (PFPD. The results showed that average glyphosate residues are significantly greater at 5 cm (0.09 mg kg-1 than the other depths (30 and 60 cm, having a difference of 0.078 mg kg-1 between them (P < 0.03. Glyphosate concentration time profiles were similar; it reached maximum soil concentration in a range of 10 to 18 days after application. The half-life of glyphosate in soil has an average of 39 days at all depths. Our data suggests that the release in soil of glyphosate applied to weeds delays its transference to soil by 14 days, and extends residue half life to 55 days after application. These results could be the basis for further research, including more environmental parameters that could affect the dissipation or degradation process in soil.

  16. Stimulation of bacteria and protists in rhizosphere of glyphosate-treated barley

    DEFF Research Database (Denmark)

    Imparato, Valentina; Santos, Susana; Johansen, Anders

    2016-01-01

    Glyphosate is extensively used for weed control and to ripen crops. Despite a number of studies on the direct effect of glyphosate on plants and soil organisms, only little is known about indirect effect of glyphosate on rhizosphere microbial communities, following the accelerated turnover...... of the fast-dying root biomass. In microcosms we studied the indirect effect of glyphosate on the microbial community in the rhizosphere of barley with phyllosphere application of glyphosate in comparison to leaving the plant intact or cutting off the shoot. Attempting to link the response of bacterial...... and protist communities to foliar application of glyphosate, we measured bacterial and protist abundance, diversity and physiological status, as well as soil organic carbon. Foliar application of glyphosate doubled bacterial abundance of the culturable fraction present in the rhizosphere compared to the other...

  17. Study of glyphosate transport through suspended particulate matter

    Science.gov (United States)

    Amiot, Audrey; Landry, David; Jadas-Hécart, Alain; La Jeunesse, Isabelle; Sourice, Stéphane; Ballouche, Aziz

    2014-05-01

    The results have been produced in a project aiming to improve the water quality of the Layon localy supported by stakeholders involved in the implementation of the Water Framework Directive as the SAGE-Layon Aubance. The study site is a small vineyard catchment (2.2 ha) of the Loire Valley. The slopes of the study site are between 8 and 40% resulting in strong erosive episodes during rainy event. The main objective is to understand the transfer of pesticide residues to stream. Preliminary results have shown glyphosate can be found with high concentrations during runoff. However this study was realized only in the dissolved phase. The objective is now to understand the glyphosate transport driven by SPM. The methodology developed has been (i) characterization and production of the erodible water fraction from soils aggregates; (ii) achievement of the adsorption of glyphosate on these erodible materials to compare this results with adsorption on soil sieved to 2 mm, (iii) achievement of the desorption of glyphosate on these erodible materials. Measurements have been performed on soil samples distinguishing weed or grassed soils. Soils are sieved to 2 mm or between 2 and 5 mm (to produce the erodible water fraction). Both fractions are then used to glyphosate sorption and desorption. The erodible fraction was produce with a wet sieving machine (eijkelkampt Method Kemper and Rosenau, 1986), using sieve porosity of 250 microns. The fraction obtained at 250 microns is considered to be the erodible water fraction and is used to study the adsorption and desorption of glyphosate. Kinetics has been first carried out then the isotherm to obtain the value of Kd. A ratio soil/solution of 1/5 was used. Successive desorption's method was chosen with a stirring time of 20 min, centrifugation at 6000 g and the supernatant in each desorption of 20 min is analyzed. This step is repeated 25 times. The main results of the study are: (i) adsorption of glyphosate is rapid and almost

  18. Measures to reduce glyphosate runoff from hard surfaces, 2: effect of time interval between application and first precipitation event

    NARCIS (Netherlands)

    Luijendijk, C.D.; Beltman, W.H.J.; Smidt, R.A.; Pas, van der L.J.T.; Kempenaar, C.

    2005-01-01

    In this research the effect of moisture conditions of hard surfaces on emission of herbicides from hard surfaces was quantified. In addition the dissipation of glyphosate applied on brick-pavement is determined in time. The outdoor experiment was carried out on 3 and 17 June 2003. In previous

  19. Measures to reduce glyphosate runoff from hard surfaces, 2: effect of time interval between application and first precipitation event

    NARCIS (Netherlands)

    Luijendijk, C.D.; Beltman, W.H.J.; Smidt, R.A.; Pas, van der L.J.T.; Kempenaar, C.

    2005-01-01

    In this research the effect of moisture conditions of hard surfaces on emission of herbicides from hard surfaces was quantified. In addition the dissipation of glyphosate applied on brick-pavement is determined in time. The outdoor experiment was carried out on 3 and 17 June 2003. In previous resear

  20. The herbicide glyphosate.

    Science.gov (United States)

    Malik, J; Barry, G; Kishore, G

    1989-03-01

    Glyphosate has broad spectrum herbicidal activity against a wide range of annual and perennial weeds. The environmental properties of this herbicide such as its soil immobility, rapid soil inactivation and soil biodegradation are outstanding. This herbicide is practically non-toxic to non-plant life forms such as aquatic and avian species, animals and man. Metabolism studies with pure bacterial cultures indicate that glyphosate is metabolized to either aminomethylphosphonate and glyoxylate or sarcosine and phosphate in most bacteria. The enzyme C-P lyase, which catalyzes the cleavage of the carbon-phosphorus bond of phosphonates including glyphosate, appears to be complex, containing multiple subunits. Mode of action studies have demonstrated that glyphosate kills plants by inhibiting the enzyme 5-enolpyruvylshikimate-3-phosphate synthase, involved in the biosynthesis of aromatic compounds. The status of our understanding of these aspects of glyphosate is reviewed.

  1. 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

  2. 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

  3. Molecular basis of glyphosate resistance: Different approaches through protein engineering

    Science.gov (United States)

    Pollegioni, Loredano; Schonbrunn, Ernst; Siehl, Daniel

    2011-01-01

    Glyphosate (N-phosphonomethyl-glycine) is the most-used herbicide in the world: glyphosate-based formulations exhibit broad-spectrum herbicidal activity with minimal human and environmental toxicity. The extraordinary success of this simple small molecule is mainly due to the high specificity of glyphosate towards the plant enzyme enolpyruvylshikimate-3-phosphate synthase in the shikimate pathway leading to biosynthesis of aromatic amino acids. Starting in 1996, transgenic glyphosate-resistant plants were introduced thus allowing the application of the herbicide to the crop (post-emergence) to remove emerged weeds without crop damage. This review focuses on the evolution of mechanisms of resistance to glyphosate as obtained through natural diversity, the gene shuffling approach to molecular evolution, and a rational, structure-based approach to protein engineering. In addition, we offer rationale for the means by which the modifications made have had their intended effect. PMID:21668647

  4. How glyphosate affects plant disease development: it is more than enhanced susceptibility.

    Science.gov (United States)

    Hammerschmidt, Ray

    2017-01-09

    Glyphosate has been shown to affect the development of plant disease in several ways. Plants utilize phenolic and other shikimic acid pathway-derived compounds as part of their defense against pathogens, and glyphosate inhibits the biosynthesis of these compounds via its mode of action. Several studies have shown a correlation between enhanced disease and suppression of phenolic compound production after glyphosate. Glyphosate-resistant crop plants have also been studied for changes in resistance as a result of carrying the glyphosate resistance trait. The evidence indicates that neither the resistance trait nor application of glyphosate to glyphosate-resistant plants increases susceptibility to disease. The only exceptions to this are cases where glyphosate has been shown to reduce rust diseases on glyphosate-resistant crops, supporting a fungicidal role for this chemical. Finally, glyphosate treatment of weeds or volunteer crops can cause a temporary increase in soil-borne pathogens that may result in disease development if crops are planted too soon after glyphosate application. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  5. Glyphosate effects on soil rhizosphere-associated bacterial communities.

    Science.gov (United States)

    Newman, Molli M; Hoilett, Nigel; Lorenz, Nicola; Dick, Richard P; Liles, Mark R; Ramsier, Cliff; Kloepper, Joseph W

    2016-02-01

    Glyphosate is one of the most widely used herbicides in agriculture with predictions that 1.35 million metric tons will be used annually by 2017. With the advent of glyphosate tolerant (GT) cropping more than 10 years ago, there is now concern for non-target effects on soil microbial communities that has potential to negatively affect soil functions, plant health, and crop productivity. Although extensive research has been done on short-term response to glyphosate, relatively little information is available on long-term effects. Therefore, the overall objective was to investigate shifts in the rhizosphere bacterial community following long-term glyphosate application on GT corn and soybean in the greenhouse. In this study, rhizosphere soil was sampled from rhizoboxes following 4 growth periods, and bacterial community composition was compared between glyphosate treated and untreated rhizospheres using next-generation barcoded sequencing. In the presence or absence of glyphosate, corn and soybean rhizospheres were dominated by members of the phyla Proteobacteria, Acidobacteria, and Actinobacteria. Proteobacteria (particularly gammaproteobacteria) increased in relative abundance for both crops following glyphosate exposure, and the relative abundance of Acidobacteria decreased in response to glyphosate exposure. Given that some members of the Acidobacteria are involved in biogeochemical processes, a decrease in their abundance could lead to significant changes in nutrient status of the rhizosphere. Our results also highlight the need for applying culture-independent approaches in studying the effects of pesticides on the soil and rhizosphere microbial community.

  6. Uses of glyphosate in German arable farming – operational aspects

    Directory of Open Access Journals (Sweden)

    Wiese, Armin

    2016-02-01

    Full Text Available Glyphosate is the most frequently used herbicide active ingredient in Germany. Studies regarding its usage in non-GMO arable farming are still rare even though it plays an important role in several agronomic situations. Therefore, we conducted a comprehensive survey, which was carried out among conventional German farms in Winter 2014/2015. Based on the results of this survey we analyzed via cluster analysis how types of farms differ in terms of glyphosate usage. An illustration of seven clusters allows deep insights into arable farm structures. The farm types can be distinguished regarding their tillage system and similar to this differentiation also concerning their intensity of glyphosate application. Furthermore, it becomes obvious that farm clusters with a higher level of glyphosate usage are characterized by a lower number of labourers per hectare, more arable land and/or enhanced cover cropping. Moreover, groups of farmers who rely more on glyphosate are more likely to state that they need glyphosate for herbicide resistance management. Farmers’ assessments of the economic importance of glyphosate usage vary depending on the type of farm. By means of the farm clusters, the most important situations of glyphosate usage can be further analyzed economically and scenarios for impact assessments can be made.

  7. Changes in rhizosphere bacterial gene expression following glyphosate treatment.

    Science.gov (United States)

    Newman, Molli M; Lorenz, Nicola; Hoilett, Nigel; Lee, Nathan R; Dick, Richard P; Liles, Mark R; Ramsier, Cliff; Kloepper, Joseph W

    2016-05-15

    In commercial agriculture, populations and interactions of rhizosphere microflora are potentially affected by the use of specific agrichemicals, possibly by affecting gene expression in these organisms. To investigate this, we examined changes in bacterial gene expression within the rhizosphere of glyphosate-tolerant corn (Zea mays) and soybean (Glycine max) in response to long-term glyphosate (PowerMAX™, Monsanto Company, MO, USA) treatment. A long-term glyphosate application study was carried out using rhizoboxes under greenhouse conditions with soil previously having no history of glyphosate exposure. Rhizosphere soil was collected from the rhizoboxes after four growing periods. Soil microbial community composition was analyzed using microbial phospholipid fatty acid (PLFA) analysis. Total RNA was extracted from rhizosphere soil, and samples were analyzed using RNA-Seq analysis. A total of 20-28 million bacterial sequences were obtained for each sample. Transcript abundance was compared between control and glyphosate-treated samples using edgeR. Overall rhizosphere bacterial metatranscriptomes were dominated by transcripts related to RNA and carbohydrate metabolism. We identified 67 differentially expressed bacterial transcripts from the rhizosphere. Transcripts downregulated following glyphosate treatment involved carbohydrate and amino acid metabolism, and upregulated transcripts involved protein metabolism and respiration. Additionally, bacterial transcripts involving nutrients, including iron, nitrogen, phosphorus, and potassium, were also affected by long-term glyphosate application. Overall, most bacterial and all fungal PLFA biomarkers decreased after glyphosate treatment compared to the control. These results demonstrate that long-term glyphosate use can affect rhizosphere bacterial activities and potentially shift bacterial community composition favoring more glyphosate-tolerant bacteria. Copyright © 2016 The Authors. Published by Elsevier B.V. All

  8. [Dysphonia following glyphosate exposition].

    Science.gov (United States)

    Ptok, M

    2009-11-01

    Glyphosate is a commonly used nonselective herbicide which inhibits plant growth through interference with the production of essential aromatic amino acids. Toxicity for humans has been reported after suicidal ingestion. Here we describe a 26-year-old teacher who used glyphosate correctly but suffered from severe dysphonia after some hours. Laryngostroboscopy revealed decreased vocal fold mobility suggesting innervation impairment. The symptoms resolved spontaneously 6 weeks later and vocal fold mobility returned to normal. Glyphosate neurotoxicity has been discussed in the literature therefore, the dysphonia observed here may have been due to an intermittent neuropraxia of the laryngeal nerve. However, to our knowledge a similar case has not been reported in literature.

  9. Developmental and reproductive outcomes in humans and animals after glyphosate exposure: a critical analysis.

    Science.gov (United States)

    Williams, Amy Lavin; Watson, Rebecca E; DeSesso, John M

    2012-01-01

    Glyphosate is the active ingredient of several widely used herbicide formulations. Glyphosate targets the shikimate metabolic pathway, which is found in plants but not in animals. Despite the relative safety of glyphosate, various adverse developmental and reproductive problems have been alleged as a result of exposure in humans and animals. To assess the developmental and reproductive safety of glyphosate, an analysis of the available literature was conducted. Epidemiological and animal reports, as well as studies on mechanisms of action related to possible developmental and reproductive effects of glyphosate, were reviewed. An evaluation of this database found no consistent effects of glyphosate exposure on reproductive health or the developing offspring. Furthermore, no plausible mechanisms of action for such effects were elucidated. Although toxicity was observed in studies that used glyphosate-based formulations, the data strongly suggest that such effects were due to surfactants present in the formulations and not the direct result of glyphosate exposure. To estimate potential human exposure concentrations to glyphosate as a result of working directly with the herbicide, available biomonitoring data were examined. These data demonstrated extremely low human exposures as a result of normal application practices. Furthermore, the estimated exposure concentrations in humans are >500-fold less than the oral reference dose for glyphosate of 2 mg/kg/d set by the U.S. Environmental Protection Agency (U.S. EPA 1993). In conclusion, the available literature shows no solid evidence linking glyphosate exposure to adverse developmental or reproductive effects at environmentally realistic exposure concentrations.

  10. Short-term transport of glyphosate with erosion in Chinese loess soil--a flume experiment.

    Science.gov (United States)

    Yang, Xiaomei; Wang, Fei; Bento, Célia P M; Xue, Sha; Gai, Lingtong; van Dam, Ruud; Mol, Hans; Ritsema, Coen J; Geissen, Violette

    2015-04-15

    Repeated applications of glyphosate may contaminate the soil and water and threaten their quality both within the environmental system and beyond it through water erosion related processes and leaching. In this study, we focused on the transport of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) related to soil erosion at two slope gradients (10 and 20°), two rates of pesticide with a formulation of glyphosate (Roundup®) application (360 and 720 mg m(-2)), and a rain intensity of 1.0 mm min(-1) for 1 h on bare soil in hydraulic flumes. Runoff and erosion rate were significantly different within slope gradients (psoil at the end of the experiment decreased significantly with depth (psoil layers, respectively. The risk of contamination in deep soil and the groundwater was thus low, but 5% of the initial application did reach the 2-10 cm soil layer. The risk of contamination of surface water through runoff and sedimentation, however, can be considerable, especially in regions where rain-induced soil erosion is common.

  11. Aplicação tardia de glyphosate e estande e desenvolvimento inicial do arroz em sistema de cultivo mínimo Delayed application of glyphosate and stand and initial growth of rice plants (Oryza sativa under a minimum tillage system

    Directory of Open Access Journals (Sweden)

    C.A.C. Crusciol

    2002-04-01

    Full Text Available O controle de plantas daninhas na cultura do arroz é ainda um problema, mesmo em cultivo mínimo, em razão do revolvimento do solo na linha de semeadura, que proporciona o reaparecimento de infestantes. Assim, objetivou-se estudar o efeito do atraso da aplicação de glyphosate sobre a formação do estande e o desenvolvimento inicial das plantas de arroz cv. IAC 102 irrigado por inundação. O experimento foi conduzido sob túnel plástico, em caixas d'água de 500 L, contendo NEOSSOLO FLÚVICO Ta Eutrófico. O delineamento experimental foi o de blocos casualizados, com quatro repetições. Os tratamentos consistiram da aplicação de glyphosate: seis horas antes da semeadura do arroz (testemunha; no início da emergência; três dias após a emergência; e seis dias após, sem e com lâmina d'água. A dose do herbicida foi de 1.920 g i.a. ha-1. Para todas as variáveis analisadas houve efeito significativo dos tratamentos; aos 42 dias após a emergência, constatou-se que a testemunha foi estatisticamente superior, na formação do estande, na altura de plantas, no comprimento de raiz e na massa seca das partes aérea e de raiz, aos demais tratamentos em que ocorreram atrasos na aplicação do glyphosate.Weed control is still one of the most important problems of rice production, even under a reduced-tillage system. The purpose of this research was to study the effect of delayed application of glyphosate on paddy rice cv. IAC 102. The experiment was conducted under plastic tunnels with rice plants growing in water tanks of 500 liters of capacity, containing Alluvial soil. Treatments consisted of glyphosate application on the soil surface six hours before sowing, (control at seedling emergence, three days after, and six days after, combined or not with water flooding. The experimental design was a randomized block with four replications and the herbicide dosage was 1,920 g a.i. ha-1. There was a significant effect of the treatments on the

  12. Timing of Glyphosate Applications to Wheat Cover Crops to Reduce Onion Stunting Caused by Rhizoctonia solana

    Science.gov (United States)

    Stunting caused by Rhizoctonia spp. is economically important in irrigated onion bulb crops in the semi-arid Columbia Basin of Oregon and Washington, where cereal winter cover crops commonly are planted the previous fall to prevent wind erosion of soil. The cover crop is killed with herbicide applic...

  13. Interactions of glyphosate use with farm characteristics and cropping patterns in Central Europe.

    Science.gov (United States)

    Wiese, Armin; Schulte, Michael; Theuvsen, Ludwig; Steinmann, Horst-Henning

    2017-02-02

    Although glyphosate is the most widely used herbicide in the European Union, little is known about the patterns of its usage in arable farming. Therefore, a nationwide survey of 2026 German farmers was analysed to obtain further knowledge about glyphosate applications in conventional European arable farming. Given its broad range of agri-environmental and farm-type conditions, Germany can be regarded as a suitable study region to represent Central European farming. The growing season 2013/2014 was set as a reference. Farmers who participated in the survey employ diverse patterns of glyphosate use. While 23% stated that they did not use glyphosate in the season in question, others applied glyphosate to their total arable area. However, most applications occurred on specific parts of the farm. Application patterns of oilseed rape, winter wheat, maize and sugar beet were studied in detail, and U-shaped distributions of glyphosate use intensity were observed. The effects of farm type and management practices on glyphosate use patterns were mixed in the various crops. Motivation for glyphosate use differs widely within the farming community. Agricultural researchers, extension services and policy makers are recommended to mitigate vulnerabilities associated with glyphosate use, such as routine spraying and practices that increase selection pressure for the evolution of glyphosate-resistant weeds. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Repeated application of organic waste affects soil organic matter composition

    DEFF Research Database (Denmark)

    Peltre, Clément; Gregorich, Edward G.; Bruun, Sander

    2017-01-01

    of different types of carbon compounds in soil. The objective of this study was to identify and characterise changes in soil organic matter (SOM) composition after repeated applications of organic waste. Soil from the CRUCIAL field experiment in Denmark was sampled after 12 years of annual application...... that there was accumulation in soil of different C compounds for the different types of applied organic waste, which appeared to be related to the degree to which microbial activity was stimulated and the type of microbial communities applied with the wastes or associated with the decomposition of applied wastes...

  15. Exploring the effects of glyphosate products on weed composition

    Directory of Open Access Journals (Sweden)

    Koning, Laurie Anne

    2016-02-01

    Full Text Available Glyphosate is a non-selective, broad-spectrum, systematic herbicide that is the world’s most widely used herbicide since its introduction in the 1970s as a pre-plant, post-directed and post-harvest herbicide application with further technological developments leading to its use within glyphosate resistant crops (GRCs as of the 1990s. In countries around the world, weed shifts have accompanied weed management systems employing glyphosate products. The farmer actions and weed reactions that have contributed to these weed shifts will be discussed. Evidence of glyphosate-induced weed shifts has not yet been documented in Germany, but through consideration of the conditions that have lead to glyphosate-induced weed shifts elsewhere the outlook for Germany will be assessed. An ongoing research project will be introduced in which weed monitoring is being employed to find out if glyphosate-induced weed shifts can be identified in northeastern German arable farm fields and in which field experiments are also being conducted to further explore the reactions of weed communities and populations under the intensive application of glyphosate products.

  16. Wind erosion as an environmental transport pathway of glyphosate and AMPA

    Science.gov (United States)

    Bento, Célia P. M.; Goossens, Dirk; Rezaei, Mahrooz; Riksen, Michel; Mol, Hans G. J.; Ritsema, Coen J.; Geissen, Violette

    2017-04-01

    Glyphosate is the active ingredient of many commercial formulations of herbicides extensively used worldwide for weed control. Because glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) are considered non-volatile, their loss to the atmosphere is considered negligible. Both compounds strongly adsorb to soil particles and wind-eroded sediment and dust are thus a possible environmental transport pathway. This can result in environmental and human exposure far beyond the agricultural areas where it has been applied. Therefore, special attention is required to the airborne transport of glyphosate and AMPA. In this study, we investigated the behavior of glyphosate and AMPA in wind-eroded sediment by measuring their content in different size fractions (median diameters between 715 and 8 µm) of a loess soil, during a period of 28 days after glyphosate application. Granulometrical extraction was done using a wind tunnel and a Soil Fine Particle Extractor. Extractions were conducted on days 0, 3, 7, 14, 21 and 28 after glyphosate application. Results indicated that glyphosate and AMPA contents were significantly higher in the finest particle fractions (median diameters between 8 and 18 µm), and lowered significantly with the increase in particle size. Glyphosate and AMPA contents correlated positively with clay, organic matter, and silt content. The dissipation of glyphosate over time was very low, which was associated to the low soil moisture content of the sediment. Consequently, the formation of AMPA was also very low. The low dissipation of glyphosate in our study indicates that the risk of glyphosate transport in dry sediment to off-target areas by wind can be very high. The highest glyphosate and AMPA contents were found in the smallest soil fractions (PM10 and less), which are easily inhaled. This contributes to the risk of human and animal exposure and, therefore, more attention should be paid to this route of exposure in environmental and human

  17. Physiology of Glyphosate-Resistant and Glyphosate-Susceptible Palmer Amaranth (Amaranthus palmeri Biotypes Collected from North Carolina

    Directory of Open Access Journals (Sweden)

    Jared R. Whitaker

    2013-01-01

    Full Text Available Glyphosate-resistant (GR biotypes of Palmer amaranth are now commonly found across the southern United States. Experiments were conducted to characterize physiological differences between a GR biotype and a glyphosate-susceptible (GS biotype from North Carolina. The GR biotype had an 18-fold level of resistance based upon rates necessary to reduce shoot fresh weight 50%. Shikimate accumulated in both biotypes following glyphosate application, but greater concentrations were found in GS plants. Absorption and translocation of 14C-glyphosate were studied in both biotypes with and without an overspray with commercial glyphosate potassium salt (840 g ae ha−1 immediately prior to 14C-glyphosate application. Greater absorption was noted 6 h after treatment (HAT in GS compared with GR plants, but no differences were observed at 12 to 72 HAT. Oversprayed plants absorbed 33 and 61% more 14C by 48 and 72 HAT, respectively, than plants not oversprayed. 14C distribution (above treated leaf, below treated leaf, roots was similar in both biotypes. Together, these results suggest that resistance in this biotype is not due to an altered target enzyme or translocation but may be in part due to the rate of glyphosate absorption. These results also are consistent with resistance being due to increased gene copy number for the target enzyme.

  18. Foliar-applied glyphosate substantially reduced uptake and transport of iron and manganese in sunflower (Helianthus annuus L.) plants.

    Science.gov (United States)

    Eker, Selim; Ozturk, Levent; Yazici, Atilla; Erenoglu, Bulent; Romheld, Volker; Cakmak, Ismail

    2006-12-27

    Evidence clearly shows that cationic micronutrients in spray solutions reduce the herbicidal effectiveness of glyphosate for weed control due to the formation of metal-glyphosate complexes. The formation of these glyphosate-metal complexes in plant tissue may also impair micronutrient nutrition of nontarget plants when exposed to glyphosate drift or glyphosate residues in soil. In the present study, the effects of simulated glyphosate drift on plant growth and uptake, translocation, and accumulation (tissue concentration) of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were investigated in sunflower (Helianthus annuus L.) plants grown in nutrient solution under controlled environmental conditions. Glyphosate was sprayed on plant shoots at different rates between 1.25 and 6.0% of the recommended dosage (i.e., 0.39 and 1.89 mM glyphosate isopropylamine salt). Glyphosate applications significantly decreased root and shoot dry matter production and chlorophyll concentrations of young leaves and shoot tips. The basal parts of the youngest leaves and shoot tips were severely chlorotic. These effects became apparent within 48 h after the glyphosate spray. Glyphosate also caused substantial decreases in leaf concentration of Fe and Mn while the concentration of Zn and Cu was less affected. In short-term uptake experiments with radiolabeled Fe (59Fe), Mn (54Mn), and Zn (65Zn), root uptake of 59Fe and 54Mn was significantly reduced in 12 and 24 h after application of 6% of the recommended dosage of glyphosate, respectively. Glyphosate resulted in almost complete inhibition of root-to-shoot translocation of 59Fe within 12 h and 54Mn within 24 h after application. These results suggest that glyphosate residues or drift may result in severe impairments in Fe and Mn nutrition of nontarget plants, possibly due to the formation of poorly soluble glyphosate-metal complexes in plant tissues and/or rhizosphere interactions.

  19. Losses of glyphosate and AMPA via drainflow in a typical Belgian residential area

    Science.gov (United States)

    Tang, Ting; Boënne, Wesley; van Griensven, Ann; Seuntjens, Piet; Bronders, Jan; Desmet, Nele

    2014-05-01

    Urban hard surfaces are considered as important facilitators for pesticide transport into urban streams. To obtain concurrent high-resolution data for a detailed investigation on the losses of pesticide runoff from hard surfaces, a monitoring campaign was performed in a typical Belgian residential area (9.5 ha) between 7 May and 7 August, 2013. The campaign yielded a concurrent dataset of rainfall (1-mm rainfall interval), discharge (1-min interval), glyphosate application by the residents and the occurrences of glyphosate and its major degradation product - aminomethylphosphonic acid (AMPA) in the separated storm drainage outflow during 12 rainfall events. In addition, detailed information was obtained on the spatial characteristics of the study area. The resulting dataset allows us to investigate the relevance of catchment hydrology, urban surface properties and pesticide application to the transport and losses of glyphosate in a residential environment. During the campaign, glyphosate was only applied by local residents, mainly on their private driveways. As a result of their continuous use, both glyphosate and AMPA were detected in all analysed outflow samples, with maximum concentrations of 6.1 μg/L and 5.8 μg/L, respectively. Overall, the storm drainage system collected 0.43% of the applied amount of glyphosate. However, this loss rate varied considerably among rainfall events, ranging from 0.04% to 23.36%. According to statistical analysis of the 12 rainfall events, the loss rate was significantly correlated with three factors: the application amount prior to a rainfall event (p glyphosate application and the start of the rainfall event (negatively, p glyphosate. Furthermore, three types of glyphosate runoff were classified by a clustering analysis based on these factors: events dominated by runoff availability (runoff-limited), dominated by glyphosate availability (pesticide-limited) and controlled by both runoff and glyphosate availability. To sum up

  20. 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.

  1. Trends in glyphosate herbicide use in the United States and globally

    OpenAIRE

    Charles M. Benbrook

    2016-01-01

    Background Accurate pesticide use data are essential when studying the environmental and public health impacts of pesticide use. Since the mid-1990s, significant changes have occurred in when and how glyphosate herbicides are applied, and there has been a dramatic increase in the total volume applied. Methods Data on glyphosate applications were collected from multiple sources and integrated into a dataset spanning agricultural, non-agricultural, and total glyphosate use from 1974–2014 in the...

  2. Glyphosate bioavailability in soil.

    Science.gov (United States)

    Shushkova, Tatyana; Ermakova, Inna; Leontievsky, Alexey

    2010-06-01

    Biodegradation of glyphosate in sod-podzol soil by both the indigenous micro flora and the introduced strain Ochrobactrum anthropi GPK 3 was studied with respect to its sorption and mobility. The experiments were carried out in columns simulating the vertical soil profile. Soil samples studied were taken from soil horizons 0-10, 10-20, and 20-30 cm deep. It was found out that the most of the herbicide (up to 84%) was adsorbed by soil during the first 24 h; the rest (16%) remained in the soluble fraction. The adsorbed glyphosate was completely extractable by alkali. No irreversible binding of glyphosate was observed. By the end of the experiment (21st day), glyphosate was only found in extractable fractions. The comparison of the effect of the introduced O. anthropi GPK 3 and indigenous microbial community on the total toxicant content (both soluble and absorbed) in the upper 10 cm soil layer showed its reduction by 42% (21 mg/kg soil) and 10-12% (5 mg/kg soil), respectively. Simultaneously, 14-18% glyphosate moved to a lower 10-20 cm layer. Watering (that simulated rainfall) resulted in a 20% increase of its content at this depth; 6-8% of herbicide was further washed down to the 20-30 cm layer. The glyphosate mobility down the soil profile reduced its density in the upper layer, where it was available for biodegradation, and resulted in its concentration in lower horizons characterized by the absence (or low level) of biodegradative processes. It was shown for the first time how the herbicide biodegradation in soil can be increased manifold by introduction of the selected strain O. anthropi GPK 3.

  3. Secondary effects of glyphosate on plants

    Science.gov (United States)

    Glyphosate is a unique herbicide with interesting secondary effects. Unfortunately, some have assumed that the secondary effects that occur in glyphosate-susceptible plants treated with glyphosate, such as altered mineral nutrition, reduced phenolic compound production and pathogen resistance, also ...

  4. Comparative environmental impacts of glyphosate and conventional herbicides when used with glyphosate-tolerant and non-tolerant crops

    Energy Technology Data Exchange (ETDEWEB)

    Mamy, Laure, E-mail: laure.mamy@versailles.inra.f [INRA-AgroParisTech, UMR 1091 Environnement et Grandes Cultures, 78850 Thiverval-Grignon (France); Gabrielle, Benoit, E-mail: benoit.gabrielle@agroparistech.f [INRA-AgroParisTech, UMR 1091 Environnement et Grandes Cultures, 78850 Thiverval-Grignon (France); Barriuso, Enrique, E-mail: barriuso@grignon.inra.f [INRA-AgroParisTech, UMR 1091 Environnement et Grandes Cultures, 78850 Thiverval-Grignon (France)

    2010-10-15

    The introduction of glyphosate-tolerant (GT) crops is expected to mitigate the environmental contamination by herbicides because glyphosate is less persistent and toxic than the herbicides used on non-GT crops. Here, we compared the environmental balances of herbicide applications for both crop types in three French field trials. The dynamic of herbicides and their metabolites in soil, groundwater and air was simulated with PRZM model and compared to field measurements. The associated impacts were aggregated with toxicity potentials calculated with the fate and exposure model USES for several environmental endpoints. The impacts of GT systems were lower than those of non-GT systems, but the accumulation in soils of one glyphosate metabolite (aminomethylphosphonic acid) questions the sustainability of GT systems. The magnitude of the impacts depends on the rates and frequency of glyphosate application being highest for GT maize monoculture and lowest for combination of GT oilseed rape and non-GT sugarbeet crops. - The impacts of herbicide applications on glyphosate-tolerant crops could be higher than expected due to the accumulation of a metabolite of glyphosate in soils.

  5. Glyphosate and AMPA distribution in wind-eroded sediment derived from loess soil.

    Science.gov (United States)

    Bento, Célia P M; Goossens, Dirk; Rezaei, Mahrooz; Riksen, Michel; Mol, Hans G J; Ritsema, Coen J; Geissen, Violette

    2017-01-01

    Glyphosate is one of the most used herbicides in agricultural lands worldwide. Wind-eroded sediment and dust, as an environmental transport pathway of glyphosate and of its main metabolite aminomethylphosphonic acid (AMPA), can result in environmental- and human exposure far beyond the agricultural areas where it has been applied. Therefore, special attention is required to the airborne transport of glyphosate and AMPA. In this study, we investigated the behavior of glyphosate and AMPA in wind-eroded sediment by measuring their content in different size fractions (median diameters between 715 and 8 μm) of a loess soil, during a period of 28 days after glyphosate application. Granulometrical extraction was done using a wind tunnel and a Soil Fine Particle Extractor. Extractions were conducted on days 0, 3, 7, 14, 21 and 28 after glyphosate application. Results indicated that glyphosate and AMPA contents were significantly higher in the finest particle fractions (median diameters between 8 and 18 μm), and lowered significantly with the increase in particle size. However, their content remained constant when aggregates were present in the sample. Glyphosate and AMPA contents correlated positively with clay, organic matter, and silt content. The dissipation of glyphosate over time was very low, which was most probably due to the low soil moisture content of the sediment. Consequently, the formation of AMPA was also very low. The low dissipation of glyphosate in our study indicates that the risk of glyphosate transport in dry sediment to off-target areas by wind can be very high. The highest glyphosate and AMPA contents were found in the smallest soil fractions (PM10 and less), which are easily inhaled and, therefore, contribute to human exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. The Fate and Transport of Glyphosate and AMPA into Surface Waters of Agricultural Watersheds

    Science.gov (United States)

    Coupe, R.; Kalkhoff, S.; Capel, P.; Gregoire, C.

    2010-12-01

    Glyphosate [N-(phosphonomethyl)glycine] is a herbicide used widely throughout the world in the production of many crops, but is particularly heavily used on crops which are genetically modified to be glyphosate tolerant: predominately soybeans, corn, potatoes, and cotton. Glyphosate is used extensively in almost all agricultural areas of the United States, and annual application has increased from less than 10,000 Mg in 1992 to more than 80,000 Mg in 2007. The greatest areal use is in the Midwest where glyphosate is applied on genetically modified corn and soybeans. Although use is increasing, the characterization of glyphosate transport on the watershed scale is lacking. Glyphosate, and its degradate AMPA [aminomethylphosphoric acid], was frequently detected in the surface waters of four agricultural watersheds. The load as a percent of use of glyphosate ranged from 0.009 to 0.86 percent and can be related to three factors: source strength, hydrology, and flowpath. Glyphosate use within a watershed results in some occurrence in surface water at the part per billion level; however watersheds most at risk for the offsite transport of glyphosate are those with high application rates, rainfall that results in overland runoff, and a flowpath that does not include transport through the soil.

  7. Glyphosate Effects on Plant Mineral Nutrition, Crop Rhizosphere Microbiota, and Plant Disease in Glyphosate-Resistant Crops

    Science.gov (United States)

    2012-01-01

    Claims have been made recently that glyphosate-resistant (GR) crops sometimes have mineral deficiencies and increased plant disease. This review evaluates the literature that is germane to these claims. Our conclusions are: (1) although there is conflicting literature on the effects of glyphosate on mineral nutrition on GR crops, most of the literature indicates that mineral nutrition in GR crops is not affected by either the GR trait or by application of glyphosate; (2) most of the available data support the view that neither the GR transgenes nor glyphosate use in GR crops increases crop disease; and (3) yield data on GR crops do not support the hypotheses that there are substantive mineral nutrition or disease problems that are specific to GR crops. PMID:23013354

  8. Glyphosate and Carcinogenicity Risk

    OpenAIRE

    Ötegen, Volkan Recai; Akbaba, Muhsin; Nazlıcan, Ersin

    2015-01-01

    IARC Glyphosate's IIA classification is still controversial, because dosages of this effect is not specified and also numerous studies show the opposite. However, the results must be noted by scientific institutions and public health authorities and risk assessment must be made considering doses and real-life conditions.

  9. Mineralization and degradation of glyphosate and atrazine applied in combination in a Brazilian Oxisol.

    Science.gov (United States)

    Bonfleur, Eloana J; Lavorenti, Arquimedes; Tornisielo, Valdemar L

    2011-01-01

    The aim of this study was to investigate the behavior of the association between atrazine and glyphosate in the soil through mineralization and degradation tests. Soil treatments consisted of the combination of a field dose of glyphosate (2.88 kg ha⁻¹) with 0, ½, 1 and 2 times a field dose of atrazine (3.00 kg ha⁻¹) and a field dose of atrazine with 0, ½, 1 and 2 times a field dose of glyphosate. The herbicide mineralization rates were measured after 0, 3, 7, 14, 21, 28, 35, 42, 49, 56 and 63 days of soil application, and degradation rates after 0, 7, 28 and 63 days. Although glyphosate mineralization rate was higher in the presence of 1 (one) dose of atrazine when compared with glyphosate alone, no significant differences were found when half or twice the atrazine dose was applied, meaning that differences in glyphosate mineralization rates cannot be attributed to the presence of atrazine. On the other hand, the influence of glyphosate on atrazine mineralization was evident, since increasing doses of glyphosate increased the atrazine mineralization rate and the lowest dose of glyphosate accelerated atrazine degradation.

  10. Efficacy and fate of glyphosate on Swedish railway embankments.

    Science.gov (United States)

    Torstensson, Lennart; Börjesson, Elisabet; Stenström, John

    2005-09-01

    The herbicide glyphosate, N-(phosphonomethyl)glycine, as Spectra (240 g AI litre(-1) SL; Monsanto Europe AB), RoundUp (360 g AI litre(-1) SL; Monsanto) and RoundUp Bio (360 g AI litre(-1) SL; Monsanto), have been used for weed control on Swedish railway embankments since 1986. This article summarizes results from studies of the weed effect and behaviour of glyphosate for the period 1984-2003. Studies on a railway embankment with a range of application rates showed excellent weed control at 5 litre ha(-1) of RoundUp Bio. The appearance of glyphosate and its metabolite AMPA [(aminomethyl)phosphonic acid] in the embankment, eg mobility and persistence, was also studied. Mobility was low in most cases, the main proportion of both glyphosate and AMPA being found in the upper 30-cm layer although minor amounts penetrated to lower depths. The 50% disappearance time of glyphosate was generally Bio to avoid groundwater contamination. A lower rate of glyphosate mixed with a low rate of another herbicide may achieve acceptable weed control and be environmentally safer. Copyright 2005 Society of Chemical Industry

  11. Decay characteristics and erosion-related transport of glyphosate in Chinese loess soil under field conditions

    NARCIS (Netherlands)

    Yang, X.; Wang, Fei; Martins Bento, Celia; Meng, L.; Dam, van R.C.J.; Mol, J.G.J.; Liu, Guobin; Ritsema, C.J.; Geissen, V.

    2015-01-01

    The decay characteristics and erosion-related transport of glyphosate and aminomethylphosphonic acid (AMPA) were monitored for 35 d at different slope gradients and rates of application in plots with loess soil on the Loess Plateau, China. The initial glyphosate decayed rapidly (half-life of 3.5 d)

  12. Glyphosate carryover in seed potato: effects on mother crop and daughter tubers

    Science.gov (United States)

    Field studies were conducted in 2008 and 2009 in Aberdeen, ID, Ontario, OR, and Paterson, WA to determine the effect of simulated glyphosate drift on ‘Ranger Russet’ potato during the application year and the crop growing the next year from the daughter tubers. Glyphosate was applied at 8.5, 54, 107...

  13. Glyphosate toxicity and the effects of long-term vegetation control on soil microbial communities

    Science.gov (United States)

    Matt D. Busse; Alice W. Ratcliff; Carol J. Stestak; Robert F. Powers

    2001-01-01

    We assessed the direct and indirect effect of the herbicide glyphosate on soil microbial communities from soil bioassays at glyphosate concentrations up to 100-fold greater than expected following a single field application. Indirect effects on microbial biomass, respiration, and metabolic diversity (Biolog and catabolic response profile) were compared seasonally after...

  14. Decay characteristics and erosion-related transport of glyphosate in Chinese loess soil under field conditions

    NARCIS (Netherlands)

    Yang, X.; Wang, Fei; Martins Bento, Celia; Meng, L.; Dam, van R.C.J.; Mol, J.G.J.; Liu, Guobin; Ritsema, C.J.; Geissen, V.

    2015-01-01

    The decay characteristics and erosion-related transport of glyphosate and aminomethylphosphonic acid (AMPA) were monitored for 35 d at different slope gradients and rates of application in plots with loess soil on the Loess Plateau, China. The initial glyphosate decayed rapidly (half-life of 3.5 d)

  15. Temporal Patterns of Glyphosate Leaching at a Loamy Agricultural Field in Denmark

    DEFF Research Database (Denmark)

    Nørgaard, Trine; Møldrup, Per; Olsen, Preben

    2013-01-01

    applications in combination with the effect of precipitation events, drain water runoff, soil water content at 25 cm soil depth, management, and particle leaching patterns, and compares this with monitored field-scale glyphosate and AMPA leaching to a tile drainage system. Preliminary findings indicate...... that there is an accumulation of glyphosate and AMPA in the soil after the successive applications of glyphosate, as the level of the peaking concentrations right after applications increases. Furthermore, large precipitation events with subsequent high drain water runoff together with management, especially plowing...... and harvesting, trigger the leaching of mobile colloids, glyphosate, and AMPA. As a likely consequence, glyphosate has occasionally been detected in groundwater monitoring wells installed at the location down to 3.5-4.5 m depth in concentrations exceeding the EU drinking water quality criterion....

  16. Glyphosate spray drift in Coffea arabica - sensitivity of coffee plants and possible use of shikimic acid as a biomarker for glyphosate exposure.

    Science.gov (United States)

    Schrübbers, Lars C; Valverde, Bernal E; Sørensen, Jens C; Cedergreen, Nina

    2014-10-01

    Glyphosate is widely used in coffee plantations to control weeds. Lacking selectivity, glyphosate spray drift is suspected to cause adverse effects in coffee plants. Symptoms caused by glyphosate can be similar to those produced by other stress factors. However, shikimic acid accumulation should be a useful biomarker for glyphosate exposure as shown for other crops. The aim of this study was to assess the sensitivity of coffee plants towards glyphosate on different biological response variables and to evaluate the use of shikimic acid as biomarker. Dose-response experiments yielded ED50 values (50% effect dose) in the range of 38-550 ga.e.ha(-1) depending on the quantitative or qualitative variable monitored. The frequency of plants showing symptoms was the most sensitive variable. The best sampling time for shikimic acid accumulation was 1-2 weeks after glyphosate application, depending on experimental conditions. The highest shikimic acid accumulation was observed in young leaves. Shikimic acid is a suitable biomarker for a glyphosate exposure in coffee, using only young leaves for the analysis. Young coffee plants are susceptible to glyphosate damage. If symptoms are absent the risk of severe crop damage or yield loss is low.

  17. 78 FR 60707 - Glyphosate; Pesticide Tolerances

    Science.gov (United States)

    2013-10-02

    ... AGENCY 40 CFR Part 180 Glyphosate; Pesticide Tolerances AGENCY: Environmental Protection Agency (EPA... herbicide glyphosate in or on canola, seed at 20 parts per million (ppm) by changing the tolerance expression from the combined residues of glyphosate only, to the combined residues of glyphosate and...

  18. Simulating changes in cropping practises in conventional and glyphosate-tolerant maize. I. Effects on weeds.

    Science.gov (United States)

    Colbach, Nathalie; Fernier, Alice; Le Corre, Valérie; Messéan, Antoine; Darmency, Henri

    2017-04-01

    Herbicide-tolerant (HT) crops such as those tolerant to glyphosate simplify weed management and make it more efficient, at least at short-term. Overreliance on the same herbicide though leads to the spread of resistant weeds. Here, the objective was to evaluate, with simulations, the impact on the advent of glyphosate resistance in weeds of modifications in agricultural practises resulting from introducing HT maize into cropping systems. First, we included a single-gene herbicide resistance submodel in the existing multispecific FLORSYS model. Then, we (1) simulated current conventional and probable HT cropping systems in two European regions, Aquitaine and Catalonia, (2) compared these systems in terms of glyphosate resistance, (3) identified pertinent cultural practises influencing glyphosate resistance, and (4) investigated correlations between cultural practises and species traits, using RLQ analyses. The simulation study showed that, during the analysed 28 years, (1) glyphosate spraying only results in glyphosate resistance in weeds when combined with other cultural factors favouring weed infestation, particularly no till; (2) pre-sowing glyphosate applications select more for herbicide resistance than post-sowing applications on HT crops; and (3) glyphosate spraying selects more for species traits avoiding exposure to the herbicide (e.g. delayed early growth, small leaf area) or compensating for fitness costs (e.g. high harvest index) than for actual resistance to glyphosate, (4) actual resistance is most frequent in species that do not avoid glyphosate, either via plant size or timing, and/or in less competitive species, (5) in case of efficient weed control measures, actual resistance proliferates best in outcrossing species. An advice table was built, with the quantitative, synthetic ranking of the crop management effects in terms of glyphosate-resistance management, identifying the optimal choices for each management technique.

  19. Physiological responses of glyphosate-resistant and glyphosate-sensitive soybean to aminomethylphosphonic acid, a metabolite of glyphosate.

    Science.gov (United States)

    Ding, Wei; Reddy, Krishna N; Zablotowicz, Robert M; Bellaloui, Nacer; Arnold Bruns, H

    2011-04-01

    Aminomethylphosphonic acid (AMPA) is formed in glyphosate-treated glyphosate-resistant (GR) and glyphosate-sensitive (GS) soybean [Glycine max (L.) Merr.] plants and is known to cause yellowing in soybean. Although, AMPA is less phytotoxic than glyphosate, its mode of action is different from that of glyphosate and is still unknown. Greenhouse studies were conducted at Stoneville, MS to determine the effects of AMPA on plant growth, chlorophyll content, photosynthesis, nodulation, nitrogenase activity, nitrate reductase activity, and shoot nitrogen content in GR and GS soybeans. AMPA was applied to one- to two-trifoliolate leaf stage soybeans at 0.1 and 1.0 kg ha(-1), representing a scenario of 10% and 100% degradation of glyphosate (1.0 kg ae ha(-1) use rate) to AMPA, respectively. Overall, AMPA effects were more pronounced at 1.0 kg ha(-1) than at 0.1 kg ha(-1) rate. Visual plant injury (18-27%) was observed on young leaves within 3d after treatment (DAT) with AMPA at the higher rate regardless of soybean type. AMPA injury peaked to 46-49% at 14 DAT and decreased to 17-18% by 28 DAT, in both soybean types. AMPA reduced the chlorophyll content by 37%, 48%, 66%, and 23% in GR soybean, and 17%, 48%, 57%, and 22% in GS soybean at 3, 7, 14, and 28 DAT, respectively. AMPA reduced the photosynthesis rate by 65%, 85%, and 77% in GR soybean and 59%, 88%, and 69% in GS soybean at 3, 7, and 14 DAT, respectively, compared to non-treated plants. Similarly, AMPA reduced stomatal conductance to water vapor and transpiration rates at 3, 7, and 14 DAT compared to non-treated plants in both soybean types. Photosynthesis rate, stomatal conductance, and transpiration rate recovered to the levels of non-treated plants by 28 DAT. Plant height and shoot dry weight at 28 DAT; nodulation, nitrogenase activity at 10 DAT, and nitrate reductase activity at 3 and 14 DAT were unaffected by AMPA. AMPA reduced root respiration and shoot nitrogen content at 10 DAT. These results suggest that a

  20. Glyphosate resistance: state of knowledge

    Science.gov (United States)

    Sammons, Robert Douglas; Gaines, Todd A

    2014-01-01

    Studies of mechanisms of resistance to glyphosate have increased current understanding of herbicide resistance mechanisms. Thus far, single-codon non-synonymous mutations of EPSPS (5-enolypyruvylshikimate-3-phosphate synthase) have been rare and, relative to other herbicide mode of action target-site mutations, unconventionally weak in magnitude for resistance to glyphosate. However, it is possible that weeds will emerge with non-synonymous mutations of two codons of EPSPS to produce an enzyme endowing greater resistance to glyphosate. Today, target-gene duplication is a common glyphosate resistance mechanism and could become a fundamental process for developing any resistance trait. Based on competition and substrate selectivity studies in several species, rapid vacuole sequestration of glyphosate occurs via a transporter mechanism. Conversely, as the chloroplast requires transporters for uptake of important metabolites, transporters associated with the two plastid membranes may separately, or together, successfully block glyphosate delivery. A model based on finite glyphosate dose and limiting time required for chloroplast loading sets the stage for understanding how uniquely different mechanisms can contribute to overall glyphosate resistance. PMID:25180399

  1. Glyphosate resistance: state of knowledge.

    Science.gov (United States)

    Sammons, Robert Douglas; Gaines, Todd A

    2014-09-01

    Studies of mechanisms of resistance to glyphosate have increased current understanding of herbicide resistance mechanisms. Thus far, single-codon non-synonymous mutations of EPSPS (5-enolypyruvylshikimate-3-phosphate synthase) have been rare and, relative to other herbicide mode of action target-site mutations, unconventionally weak in magnitude for resistance to glyphosate. However, it is possible that weeds will emerge with non-synonymous mutations of two codons of EPSPS to produce an enzyme endowing greater resistance to glyphosate. Today, target-gene duplication is a common glyphosate resistance mechanism and could become a fundamental process for developing any resistance trait. Based on competition and substrate selectivity studies in several species, rapid vacuole sequestration of glyphosate occurs via a transporter mechanism. Conversely, as the chloroplast requires transporters for uptake of important metabolites, transporters associated with the two plastid membranes may separately, or together, successfully block glyphosate delivery. A model based on finite glyphosate dose and limiting time required for chloroplast loading sets the stage for understanding how uniquely different mechanisms can contribute to overall glyphosate resistance. © 2014 The Authors. Pest Management Science published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.

  2. Testing Tools for Glyphosate Resistance

    Science.gov (United States)

    There are multiple tools available for testing for glyphosate resistance. Whole plant screens, whether in the field or greenhouse, should be used as an initial method to determine if a biotype is glyphosate resistant. Screening for resistance using seedling assays such as in Petri plates, sand cul...

  3. Mode of Action of Glyphosate

    Science.gov (United States)

    Although glyphosate is the most used and studied herbicide in the world, the available information is not enough to fully understand its mode of action. The molecular site of action of glyphosate is the enzyme 5-enolpyruvlyshikimate-3-phosphate synthase (EPSPS). It is the only known compound that ...

  4. Fate and transport of glyphosate and aminomethylphosphonic acid in surface waters of agricultural basins

    Science.gov (United States)

    Coupe, R.H.; Kalkhoff, S.J.; Capel, P.D.; Gregoire, C.

    2012-01-01

    Background: Glyphosate [N-(phosphonomethyl)glycine] is a herbicide used widely throughout the world in the production of many crops and is heavily used on soybeans, corn and cotton. Glyphosate is used in almost all agricultural areas of the United States, and the agricultural use of glyphosate has increased from less than 10 000 Mg in 1992 to more than 80 000 Mg in 2007. The greatest intensity of glyphosate use is in the midwestern United States, where applications are predominantly to genetically modified corn and soybeans. In spite of the increase in usage across the United States, the characterization of the transport of glyphosate and its degradate aminomethylphosphonic acid (AMPA) on a watershed scale is lacking. Results: Glyphosate and AMPA were frequently detected in the surface waters of four agricultural basins. The frequency and magnitude of detections varied across basins, and the load, as a percentage of use, ranged from 0.009 to 0.86% and could be related to three general characteristics: source strength, rainfall runoff and flow route. Conclusions: Glyphosate use in a watershed results in some occurrence in surface water; however, the watersheds most at risk for the offsite transport of glyphosate are those with high application rates, rainfall that results in overland runoff and a flow route that does not include transport through the soil. ?? 2011 Society of Chemical Industry.

  5. Annual Glyphosate Treatments Alter Growth of Unaffected Bentgrass (Agrostis) Weeds and Plant Community Composition

    Science.gov (United States)

    Ahrens, Collin W.; Auer, Carol A.

    2012-01-01

    Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB) and redtop (RT), where the glyphosate resistance (GR) trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities. PMID:23226530

  6. Annual glyphosate treatments alter growth of unaffected bentgrass (Agrostis) weeds and plant community composition.

    Science.gov (United States)

    Ahrens, Collin W; Auer, Carol A

    2012-01-01

    Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB) and redtop (RT), where the glyphosate resistance (GR) trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities.

  7. Annual glyphosate treatments alter growth of unaffected bentgrass (Agrostis weeds and plant community composition.

    Directory of Open Access Journals (Sweden)

    Collin W Ahrens

    Full Text Available Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB and redtop (RT, where the glyphosate resistance (GR trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities.

  8. Research on the weed control degree and glyphosate soil biodegradation in apple plantations (Pioneer variety

    Directory of Open Access Journals (Sweden)

    Ersilia ALEXA

    2010-05-01

    Full Text Available In this study we follow control degree of glyphosate herbicide on weeds in apple plantations (Pioneer variety of the Research Station Timisoara. It was also followed glyphosate biodegradation capacity in the soil by determining the amount of CO2 released by the action of microorganisms on C14 glyphosate marked isotope. Laboratory analysis of glyphosate residues in soil was made using a Liquid Scintillation TRIATHLER. Glyphosate biodegradation ability in the presence of soil microorganisms is high, so glyphosate residues remaining in soil, in terms of its use in weed combating, are minimal. Study of glyphosate biodegradation capacity in the experimental field indicates that the CO2 fraction accumulated after 50 days is 28.02% for samples exposed in the experimental field. Weather conditions, especially temperature variations between day and night, influences the activity of soilmicroorganisms and affect biodegraded glyphosate percentage.Chemical method of weed control consisted in: herbicide used was Roundup 3 l/ha (glyphosate isopropyl amine salt 360 g/l and are based on chemical application on weeds, on the rows of trees, on their uptake and translocation in their organs having as principal scope the total destruction of weeds. The experimental results obtained reveal a weed combat degree of 82.98% , in the case of chemical variant, compared with control variant. The species combated mainly due to glyphosate herbicide, which is no longer found in the final mapping are: Capsella bursa-pastoris, Chenopodium album, Echinochloa crus-galli, Plantago major, Polygonum aviculare. Total combated weeds /m2 with glyphosate is 126.67.

  9. Glyphosate effect on shikimate, nitrate reductase activity, yield, and seed composition in corn.

    Science.gov (United States)

    Reddy, Krishna N; Bellaloui, Nacer; Zablotowicz, Robert M

    2010-03-24

    When glyphosate is applied to glyphosate-resistant (GR) crops, drift to nonglyphosate-resistant (non-GR) crops may cause significant injury and reduce yields. Tools are needed to quantify injury and predict crop losses. In this study, glyphosate drift was simulated by direct application at 12.5% of the recommended label rate to non-GR corn (Zea mays L.) at 3 or 6 weeks after planting (WAP) during two field seasons in the Mississippi delta region of the southeastern USA. Visual plant injury, shikimate accumulation, nitrate reductase activity, leaf nitrogen, yield, and seed composition were evaluated. Effects were also evaluated in GR corn and GR corn with stacked glufosinate-resistant gene at the recommended label rate at 3 and 6 WAP. Glyphosate at 105 g ae/ha was applied once at 3 or 6 weeks after planting to non-GR corn. Glyphosate at 840 (lower label limit) or 1260 (upper label limit) g ae/ha was applied twice at 3 and 6 WAP to transgenic corn. Glyphosate caused injury (45-55%) and increased shikimate levels (24-86%) in non-GR compared to nontreated corn. In non-GR corn, glyphosate drift did not affect starch content but increased seed protein 8-21% while reducing leaf nitrogen reductase activity 46-64%, leaf nitrogen 7-16%, grain yield 49-54%, and seed oil 18-23%. In GR and GR stacked with glufosinate-resistant corn, glyphosate applied at label rates did not affect corn yield, leaf and seed nitrogen, or seed composition (protein, oil, and starch content). Yet, nitrate reductase activity was reduced 5-19% with glyphosate at 840 + 840 g/ha rate and 8-42% with glyphosate at 1260 + 1260 g/ha rate in both GR and GR stacked corn. These results demonstrate the potential for severe yield loss in non-GR corn exposed to glyphosate drift.

  10. Resposta de cultivares de algodoeiro a subdoses de glyphosate Response of cotton cultivars to reduced rates of glyphosate

    Directory of Open Access Journals (Sweden)

    O.M. Yamashita

    2005-12-01

    , BRS Facual, Antares and Coodetec 407. The plants were cultivated in plastic pots filled with soil substratum and kept under greenhouse conditions. Glyphosate application was performed 20 days post emergence, at which time they presented four true leaves. Reduced rates of glyphosate, simulating drift, ranged from 270 and 540 g. A control was also used, without herbicide application to compare the effects. Weekly evaluations were accomplished up to 42 days after application (DAA. During this period, plant height was also measured. Visual symptoms began 3 DAA, with the appearance of yellow spots at the tips of the youngest leaves, followed by withering at the apex of the plants. At the rate of 270 g ha-1, these symptoms showed low intensity but at the rate of 540 g ha-1 the symptoms caused "worrisome" to "very high'' toxicity, in most of the cases. BRS Facual and FM 986 were the most susceptible. Plant height was the most affected when the lowest glyphosate dose was applied. All cultivars treated with 270 g ha-1 glyphosate rate until 42 DAA were recovered. Fabrika, Coodetec 407, BRS Facual and ITA-90 cultivars, when treated with 540 g ha-1 glyphosate were more sensitive, presenting a height reduction between 84 and 90% 42 DAA. The less sensitive cultivars at the rate of 270 g ha-1 glyphosate were not the same at the 540 g ha-1 rate.

  11. Glyphosate Can Decrease Germination of Glyphosate-Resistant Soybeans.

    Science.gov (United States)

    Gomes, Marcelo Pedrosa; Bicalho, Elisa Monteze; Smedbol, Élise; Cruz, Fernanda Vieira da Silva; Lucotte, Marc; Garcia, Queila Souza

    2017-03-22

    We investigated the effects of different concentrations of glyphosate acid and one of its formulations (Roundup) on seed germination of two glyphosate-resistant (GR) and one non-GR variety of soybean. As expected, the herbicide affected the shikimate pathway in non-GR seeds but not in GR seeds. We observed that glyphosate can disturb the mitochondrial electron transport chain, leading to H2O2 accumulation in soybean seeds, which was, in turn, related to lower seed germination. In addition, GR seeds showed increased activity of antioxidant systems when compared to non-GR seeds, making them less vulnerable to oxidative stress induced by glyphosate. The differences in the responses of GR varieties to glyphosate exposure corresponded to their differences in enzymatic activity related to H2O2 scavenging and mitochondrial complex III (the proposed site of ROS induction by glyphosate). Our results showed that glyphosate ought to be used carefully as a pre-emergence herbicide in soybean field crop systems because this practice may reduce seed germination.

  12. DISPERSION OF GLYPHOSATE IN SOILS UNDERGOING EROSION

    Directory of Open Access Journals (Sweden)

    Gorana Todorovic Rampazzo

    2010-08-01

    Full Text Available Different physical, chemical and biological processes influence the behaviour of organic contaminants in soils. A better understanding of the organic pollutant behaviour in soils would improve the environmental protection. One possible way for better attenuation of the risk of pollution in agriculture can be achieved through ta better-specified pesticide management based on the adaptation of the pesticide type and application rates to the specific environmental characteristics of the area of application. Nowadays, one of the actually most applied herbicide world wide is glyphosate. Glyphosate is highly water soluble and traces have been found in surface and groundwater systems. For a better understanding of the natural influence of erosion processes on glyphosate behaviour and dispersion under heavy rain conditions after application in the field, two erosion simulation experiments were conducted on two different locations in Austria with completely different soil types in September 2008. The results of the experiments showed that under normal practical conditions (e.g. no rainfall is expected immediatly after application, the potential adsorption capacity of the Kirchberg soil (Stagnic Cambisol, with about 16.000 ppm Fe-oxides is confirmed compared to the low adsorption Chernosem soil (about 8.000 ppm pedogenic Fe-oxides.  Considering the enormous difference in the run-off amounts between the two sites Pixendorf and Kirchberg soils it can be concluded how important the soil structural conditions and vegetation type and cover are for the risks of erosion and, as a consequence, pollution of neighbouring waters. In the rainfall experiments under comparable simulation conditions, the amount of run-off was about 10 times higher at Kirchberg, owing to its better infiltration rate, than at the Pixendorf site. Moreover, the total loss of glyphosate (NT+CT through run-off at the Kirchberg site was more than double that at Pixendorf, which confirms the

  13. Glyphosate and aminomethylphosphonic acid chronic risk assessment for soil biota.

    Science.gov (United States)

    von Mérey, Georg; Manson, Philip S; Mehrsheikh, Akbar; Sutton, Peter; Levine, Steven L

    2016-11-01

    Glyphosate is a broad-spectrum herbicide used widely in agriculture, horticulture, private gardens, and public infrastructure, where it is applied to areas such as roadsides, railway tracks, and parks to control the growth of weeds. The exposure risk from glyphosate and the primary soil metabolite aminomethylphosphonic acid (AMPA) on representative species of earthworms, springtails, and predatory soil mites and the effects on nitrogen-transformation processes by soil microorganisms were assessed under laboratory conditions based on internationally recognized guidelines. For earthworms, the reproductive no-observed-effect concentration (NOEC) was 472.8 mg glyphosate acid equivalent (a.e.)/kg dry soil, which was the highest concentration tested, and 198.1 mg/kg dry soil for AMPA. For predatory mites, the reproductive NOEC was 472.8 mg a.e./kg dry soil for glyphosate and 320 mg/kg dry soil for AMPA, the highest concentrations tested. For springtails, the reproductive NOEC was 472.8 mg a.e./kg dry soil for glyphosate and 315 mg/kg dry soil for AMPA, the highest concentrations tested. Soil nitrogen-transformation processes were unaffected by glyphosate and AMPA at 33.1 mg a.e./kg soil and 160 mg/kg soil, respectively. Comparison of these endpoints with worst-case soil concentrations expected for glyphosate (6.62 mg a.e./kg dry soil) and AMPA (6.18 mg/kg dry soil) for annual applications at the highest annual rate of 4.32 kg a.e./ha indicate very low likelihood of adverse effects on soil biota. Environ Toxicol Chem 2016;35:2742-2752. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.

  14. Molecular basis of glyphosate resistance-different approaches through protein engineering.

    Science.gov (United States)

    Pollegioni, Loredano; Schonbrunn, Ernst; Siehl, Daniel

    2011-08-01

    Glyphosate (N-phosphonomethyl-glycine) is the most widely used herbicide in the world: glyphosate-based formulations exhibit broad-spectrum herbicidal activity with minimal human and environmental toxicity. The extraordinary success of this simple, small molecule is mainly attributable to the high specificity of glyphosate for the plant enzyme enolpyruvyl shikimate-3-phosphate synthase in the shikimate pathway, leading to the biosynthesis of aromatic amino acids. Starting in 1996, transgenic glyphosate-resistant plants were introduced, thus allowing application of the herbicide to the crop (post-emergence) to remove emerged weeds without crop damage. This review focuses on mechanisms of resistance to glyphosate as obtained through natural diversity, the gene-shuffling approach to molecular evolution, and a rational, structure-based approach to protein engineering. In addition, we offer a rationale for the means by which the modifications made have had their intended effect.

  15. Fate of glyphosate and degradates in cover crop residues and underlying soil: A laboratory study.

    Science.gov (United States)

    Cassigneul, A; Benoit, P; Bergheaud, V; Dumeny, V; Etiévant, V; Goubard, Y; Maylin, A; Justes, E; Alletto, L

    2016-03-01

    The increasing use of cover crops (CC) may lead to an increase in glyphosate application for their destruction. Sorption and degradation of (14)C-glyphosate on and within 4 decaying CC-amended soils were compared to its fate in a bare soil. (14)C-Glyphosate and its metabolites distribution between mineralized, water-soluble, NH4OH-soluble and non-extractable fractions was determined at 5 dates during a 20 °C/84-d period. The presence of CC extends (14)C-glyphosate degradation half-life from 7 to 28 days depending on the CC. (14)C-Glyphosate dissipation occurred mainly through mineralization in soils and through mineralization and bound residue formation in decaying CC. Differences in sorption and degradation levels were attributed to differences in composition and availability to microorganisms. CC- and soil-specific dissipation patterns were established with the help of explicit relationships between extractability and microbial activity.

  16. Fate and transport of glyphosate and aminomethylphosphonic acid in surface waters of agricultural basins

    Science.gov (United States)

    Gregoire, Caroline; Capel, Paul D.; Coupe, Richard H.; Kalkhoff, Stephen J.

    2011-01-01

    BACKGROUND: Glyphosate [N-(phosphonomethyl)glycine] is a herbicide used widely throughout the world in the production of many crops and is heavily used on soybeans, corn and cotton. Glyphosate is used in almost all agricultural areas of the United States, and the agricultural use of glyphosate has increased from less than 10 000 Mg in 1992 to more than 80 000 Mg in 2007. The greatest intensity of glyphosate use is in the midwestern United States, where applications are predominantly to genetically modified corn and soybeans. In spite of the increase in usage across the United States, the characterization of the transport of glyphosate and its degradate aminomethylphosphonic acid (AMPA) on a watershed scale is lacking.

  17. Differential susceptibility and resistance to glyphosate in annual ryegrass and wavy-leaved fleabane

    Directory of Open Access Journals (Sweden)

    Flávia Regina da Costa

    2014-09-01

    Full Text Available Annual ryegrass (Lolium multiflorum and wavy-leaved fleabane (Conyza bonariensis were tested, aiming to investigate the dose-response of biotypes of both species to glyphosate. Glyphosate herbicide at doses varying from 0 up to 1.440 g e.a. ha-1 was sprayed onto annual ryegrass plants showed four leaves and wavy-leaved fleabane showed three pair of leaves. The fresh weight of shoot was obtained at 21 days after herbicide application. The response of biotypes of L. multiflorum and C. bonariensis to glyphosate was clearly different. For L. multiflorum, the S2, R1, and R3 biotypes supported glyphosate doses 1.5, 3.0, and 8.3 times higher than the biotype S1. For C. bonariensis, the S2 and R biotypes supported glyphosate doses 2.0 and 15.5 times higher than the biotype S1. We found a low glyphosate-resistant (R1 and a high glyphosate-resistant (R2 biotypes of L. multiflorum, in agricultural regions where other biotypes had been found. In addition, a high glyphosate-resistant (R biotype of C. bonariensis was identified in an agricultural area of Santa Catarina State, Brazil, where weed resistant was not previously found.

  18. Fate of glyphosate and degradates in cover crop residues and underlying soil: A laboratory study

    Energy Technology Data Exchange (ETDEWEB)

    Cassigneul, A. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France); INRA, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Benoit, P.; Bergheaud, V.; Dumeny, V.; Etiévant, V. [INRA, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Goubard, Y. [AgroParisTech, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Maylin, A. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France); Justes, E. [INRA, UMR 1248 AGIR Auzeville — BP 52 627, 31 326, Castanet-Tolosan cedex (France); Alletto, L. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France)

    2016-03-01

    The increasing use of cover crops (CC) may lead to an increase in glyphosate application for their destruction. Sorption and degradation of {sup 14}C-glyphosate on and within 4 decaying CC-amended soils were compared to its fate in a bare soil. {sup 14}C-Glyphosate and its metabolites distribution between mineralized, water-soluble, NH{sub 4}OH-soluble and non-extractable fractions was determined at 5 dates during a 20 °C/84-d period. The presence of CC extends {sup 14}C-glyphosate degradation half-life from 7 to 28 days depending on the CC. {sup 14}C-Glyphosate dissipation occurred mainly through mineralization in soils and through mineralization and bound residue formation in decaying CC. Differences in sorption and degradation levels were attributed to differences in composition and availability to microorganisms. CC- and soil-specific dissipation patterns were established with the help of explicit relationships between extractability and microbial activity. - Highlights: • Glyphosate sorption on cover crop residues increases with their decomposition degree. • Glyphosate degradation and mineralization are lower in mulch than in soil. • Nonextractable residue formation is one of the main dissipation pathways of glyphosate in cover crop mulch.

  19. Influence of soil tillage and erosion on the dispersion of glyphosate and aminomethylphosphonic acid in agricultural soils

    Science.gov (United States)

    Todorovic, Gorana Rampazzo; Rampazzo, Nicola; Mentler, Axel; Blum, Winfried E. H.; Eder, Alexander; Strauss, Peter

    2014-03-01

    Erosion processes can strongly influence the dissipation of glyphosate and aminomethylphosphonic acid applied with Roundup Max® in agricultural soils; in addition, the soil structure state shortly before erosive precipitations fall can be a key parameter for the distribution of glyphosate and its metabolite. Field rain simulation experiments showed that severe erosion processes immediately after application of Roundup Max® can lead to serious unexpected glyphosate loss even in soils with a high presumed adsorption like the Cambisols, if their structure is unfavourable. In one of the no-tillage-plot of the Cambisol, up to 47% of the applied glyphosate amount was dissipated with surface run-off. Moreover, at the Chernozem site with high erosion risk and lower adsorption potential, glyphosate could be found in collected percolation water transported far outside the 2x2 m experimental plots. Traces of glyphosate were found also outside the treated agricultural fields.

  20. Methyldibromoglutaronitrile allergy: relationship between patch test and repeated open application test thresholds

    DEFF Research Database (Denmark)

    Fischer, L.A.; Johansen, J.D.; Menne, T.

    2008-01-01

    a significant relationship between the patch test and the repeated open application test (ROAT) reactivity. Objectives To study the relationship between elicitation threshold doses at single occluded exposure and repeated open application, using MDBGN as the allergen. Methods Eighteen subjects allergic to MDBGN...

  1. Repeated Games With Intervention: Theory and Applications in Communications

    CERN Document Server

    Xiao, Yuanzhang; van der Schaar, Mihaela

    2011-01-01

    In communication systems where users share common resources, users' selfish behavior usually results in suboptimal resource utilization. There have been extensive works that model communication systems with selfish users as one-shot games and propose incentive schemes to achieve Pareto optimal action profiles as non-cooperative equilibria. However, in many communication systems, due to strong negative externalities among users, the sets of feasible payoffs in one-shot games are nonconvex. Thus, it is possible to expand the set of feasible payoffs by having users choose convex combinations of different payoffs. In this paper, we propose a repeated game model generalized by intervention. First, we use repeated games to convexify the set of feasible payoffs in one-shot games. Second, we combine conventional repeated games with intervention, originally proposed for one-shot games, to achieve a larger set of equilibrium payoffs and loosen requirements for users' patience to achieve it. We study the problem of maxi...

  2. Resistência de Conyza canadensis e C. bonariensis ao herbicida glyphosate Glyphosate-resistance in Conyza canadensis and C. bonariensis

    Directory of Open Access Journals (Sweden)

    M.S. Moreira

    2007-03-01

    located in two different São Paulo state regions; and a susceptible one, collected in an area without herbicide application history. The experimental design adopted was randomized blocks, with four replicates. For each species, the treatments were the result of a factorial combination among the three populations and the herbicide treatments (eight rates of glyphosate or five alternative treatments. The glyphosate rates used were (g e.a. ha-1: 90, 180, 360, 720, 1.440, 2.880, 5.760 and checks without application. As control alternative, the following treatments (g ha-1 were tested: glyphosate + 2,4-D (1.440 + 1.005, glyphosate + metsulfuron (1.440 + 2,4, glyphosate + metsulfuron (1.440 + 3,6, glyphosate + metribuzin (1440 + 480 and checks without application. The results obtained proved the existence of populations of both species with glyphosate-resistant biotypes, with different levels of resistance. All the alternative herbicide treatments controlled efficiently the three populations of each species.

  3. Effects of glyphosate and foliar amendments on activity of microorganisms in the soybean rhizosphere.

    Science.gov (United States)

    Means, Nathan E; Kremer, Robert J; Ramsier, Clifford

    2007-02-01

    A field study was conducted to determine the effects of glyphosate on microbial activity in the rhizosphere of glyphosate-resistant (GR) soybean and to evaluate interactions with foliar amendments. Glyphosate at 0.84 kg ae ha(-1) was applied GR soybean at the V4-V5 development stages. Check treatments included a conventional herbicide tank mix (2003 study only) and no herbicides (hand-weeded). Ten days after herbicide application, a commercially available biostimulant and a urea solution (21.0% N) were applied to soybean foliage at 33.5 mL ha(-1) and 9.2 kg ha(-1), respectively. Soil and plant samples were taken 0, 5, 10, 15, 20 and 25 days after herbicide application then assayed for enzyme and respiration activities. Soil respiration and enzyme activity increased with glyphosate and foliar amendment applications during the 2002 growing season; however, similar increases were not observed in 2003. Contrasting cumulative rainfall between 2002 and 2003 likely accounted for differences in soil microbial activities. Increases in soil microbial activity in 2002 suggest that adequate soil water and glyphosate application acted together to increase microbial activity. Our study suggests that general soil microbial properties including those involving C and N transformations are not sensitive enough to detect effects of glyphosate on rhizosphere microbial activity. Measurements of soil-plant-microbe relationships including specific microbial groups (i.e., root-associated Fusarium spp.) are likely better indicators of impacts of glyphosate on soil microbial ecology.

  4. Impacto do glyphosate associado a inseticida e fungicida na atividade microbiana e no potencial de solubilização de fosfato em solo cultivado com soja Roundup Ready® Impact of glyphosate associated with insecticide and fungicide application on the microbial activity and potential phosphate solubilization in soil cultivated with Roundup Ready® soybean

    Directory of Open Access Journals (Sweden)

    M.R. Reis

    2009-01-01

    and phosphate solubilization potential of a soil cultivated with soybean under different phytosanitary management strategies. The experiment was conducted in the field in a Cambic red-yellow Argisol. Ten treatments were arranged in a randomized block design with four replications. The effect of fungicide + herbicide application (endosulphan + tebuconazole was evaluated in the plots, while weed control management was studied in the subplots (hoed or unhoed control; single-dose or sequential glyphosate application; single-dose fomesafen + fluazifop-p-butil application. Soil samples from the inter-row were collected when plants reached the R2 stage and were used to measure soil respiratory rate, microbial biomass carbon (MBC, metabolic quotient (qCO2, phosphate solubilization potential, and pH. The phyto-sanitary management strategies evaluated did not affect soil respiratory rates. The herbicides tested influenced soil MBC and qCO2, variables directly related to soil quality. Glyphosate applied in a single dose or sequentially, either in combination with endosulphan + tebuconazole or not, led to lower qCO2 values (0.075-0.079 mg μg-1 d-1 and higher MBC (239.64 - 312.82 μg g-1, indicating less soil disturbance. Higher phosphate solubilizing activity, 425 and 472 mg L-1 , were observed for the treatments with single-dose or sequential application of glyphosate, respectively, in the absence of endosulfan + tebuconazole. Agrochemical application on soybean shoots affects the activity of soil microorganisms in the plant rhizosphere.

  5. DIFFERENTIAL RESPONSE OF CLONES OF EUCALYPT TO GLYPHOSATE1

    Directory of Open Access Journals (Sweden)

    Leonardo Bianco de Carvalho

    2015-02-01

    Full Text Available Weed control is commonly performed by the inter-row mechanical weeding associated to intrarow glyphosate directed spraying, causing a risk for drift or accidental herbicide application, that can affect the crop of interest. The objective was to evaluate the response of clones C219, GG100, I144, and I224 of eucalypt (Eucalyptus grandis x E. urophylla to glyphosate doses of 0, 18, 36, 72, 180, 360, and 720 g of acid equivalent per hectare. The clones showed different growth patterns with regard to height, leaf number, stem dry weight, relative growth rate, net assimilation rate, and relative leaf growth rate. The clones I144 and GG100 were more susceptible to glyphosate, showing the doses required to reduce dry weight by 50% of 113.4 and 119.6 g acid equivalent per hectare, respectively. The clones C219 and I224 were less susceptible to glyphosate, showing the doses required to reduce dry weight by 50% of 237.5 and 313.5 g acid equivalent per hectare, respectively. Eucalyptus clones respond differently to glyphosate exposure, so that among I224, C219, GG100, and I144, the susceptibility to the herbicide is increasing.

  6. Yield of glyphosate-resistant sugar beets and efficiency of weed management systems with glyphosate and conventional herbicides under German and Polish crop production.

    Science.gov (United States)

    Nichterlein, Henrike; Matzk, Anja; Kordas, Leszek; Kraus, Josef; Stibbe, Carsten

    2013-08-01

    In sugar beet production, weed control is one of the most important and most expensive practices to ensure yield. Since glyphosate-resistant sugar beets are not yet approved for cultivation in the EU, little commercial experience exists with these sugar beets in Europe. Experimental field trials were conducted at five environments (Germany, Poland, 2010, 2011) to compare the effects of glyphosate with the effects of conventional weed control programs on the development of weeds, weed control efficiency and yield. The results show that the glyphosate weed control programs compared to the conventional methods decreased not only the number of herbicide applications but equally in magnitude decreased the dosage of active ingredients. The results also showed effective weed control with glyphosate when the weed covering was greater and sugar beets had a later growth stage of four true leaves. Glyphosate-resistant sugar beets applied with the glyphosate herbicide two or three times had an increase in white sugar yield from 4 to 18 % in comparison to the high dosage conventional herbicide systems. In summary, under glyphosate management sugar beets can positively contribute to the increasingly demanding requirements regarding efficient sugar beet cultivation and to the demands by society and politics to reduce the use of chemical plant protection products in the environment.

  7. Facile, green and clean one-step synthesis of carbon dots from wool: Application as a sensor for glyphosate detection based on the inner filter effect.

    Science.gov (United States)

    Wang, Long; Bi, Yidan; Hou, Juan; Li, Huiyu; Xu, Yuan; Wang, Bo; Ding, Hong; Ding, Lan

    2016-11-01

    In this work, we reported a green route for the fabrication of fluorescent carbon dots (CDs). Wool, a kind of nontoxic and natural raw material, was chosen as the precursor to prepare CDs via a one-step microwave-assisted pyrolysis process. Compared with previously reported methods for preparation of CDs based on biomass materials, this method was simple, facile and free of any additives, such as acids, bases, or salts, which avoid the complicated post-treatment process to purify the CDs. The CDs have a high quantum yield (16.3%) and their fluorescence could be quenched by silver nanoparticles (AgNPs) based on inner filter effect (IFE). The presence of glyphosate could induce the aggregation of AgNPs and thus result in the fluorescence recovery of the quenched CDs. Based on this phenomenon, we constructed a fluorescence system (CDs/AgNPs) for determination of glyphosate. Under the optimized conditions, the fluorescence intensity of the CDs/AgNPs system was proportional to the concentration of glyphosate in the range of 0.025-2.5μgmL(-1), with a detection limit of 12ngmL(-1). Furthermore, the established method has been successfully used for glyphosate detection in the cereal samples with satisfactory results.

  8. Study on pretreatment of the glyphosate wastewater and its engineering application%草甘膦废水预处理研究与工程应用

    Institute of Scientific and Technical Information of China (English)

    梅荣武; 韦彦斐; 沈浙萍; 陈雳华

    2012-01-01

    某草甘膦废水处理站已无法达到处理要求,需要进行改造.为了减轻后续的生化处理负荷,强化对草甘膦废水的除磷预处理,选用电絮凝氧化、Fenton氧化和电磁-Fenton氧化3种工艺作为草甘膦废水预处理工艺,进行了比选试验.试验结果表明,Fenton氧化为本工程的草甘膦废水最佳预处理工艺,可达到预期效果.%Some glyphosate wastewater treatment station could not meet the treatment requirements and needed to be upgraded. To reduce the biological treatment load of the following process, the dephosphorization - pretreatment process for glyphosate wastewater was enhanced. Three processes, including electric flocculation-oxidation, Fenton oxidation, and electromagnetism-Fen-ton oxidation were tested and studied to select the best pretreatment for glyphosate wastewater. The results showed: as the pretreatment for glyphosate wastewater in this project, Fenton oxidation could meet the expected standards.

  9. 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.

  10. Degradation Dynamics of Glyphosate in Different Types of Citrus Orchard Soils in China

    Directory of Open Access Journals (Sweden)

    Changpeng Zhang

    2015-01-01

    Full Text Available Glyphosate formulations that are used as a broad-spectrum systemic herbicide have been widely applied in agriculture, causing increasing concerns about residues in soils. In this study, the degradation dynamics of glyphosate in different types of citrus orchard soils in China were evaluated under field conditions. Glyphosate soluble powder and aqueous solution were applied at 3000 and 5040 g active ingredient/hm2, respectively, in citrus orchard soils, and periodically drawn soil samples were analyzed by high performance liquid chromatography. The results showed that the amount of glyphosate and its degradation product aminomethylphosphonic acid (AMPA in soils was reduced with the increase of time after application of glyphosate formulations. Indeed, the amount of glyphosate in red soil from Hunan and Zhejiang Province, and clay soil from Guangxi Province varied from 0.13 to 0.91 µg/g at 42 days after application of aqueous solution. Furthermore, the amount of glyphosate in medium loam from Zhejiang and Guangdong Province, and brown loam from Guizhou Province varied from less than 0.10 to 0.14 µg/g, while the amount of AMPA varied from less than 0.10 to 0.99 µg/g at 42 days after application of soluble powder. Overall, these findings demonstrated that the degradation dynamics of glyphosate aqueous solution and soluble powder as well as AMPA depend on the physicochemical properties of the applied soils, in particular soil pH, which should be carefully considered in the application of glyphosate herbicide.

  11. Glyphosate effects on gas exchange and chlorophyll fluorescence responses of two Lolium perenne L. biotypes with differential herbicide sensitivity.

    Science.gov (United States)

    Yanniccari, Marcos; Tambussi, Eduardo; Istilart, Carolina; Castro, Ana María

    2012-08-01

    Despite the extensive use of glyphosate, how it alters the physiology and metabolism of plants is still unclear. Photosynthesis is not regarded to be a primary inhibitory target of glyphosate, but it has been reported to be affected by this herbicide. The aim of the current research was to determine the effects of glyphosate on the light and dark reactions of photosynthesis by comparing glyphosate-susceptible and glyphosate-resistant Lolium perenne biotypes. After glyphosate treatment, accumulation of reduced carbohydrates occurred before a decrease in gas exchange. Stomatal conductance and CO(2) assimilation were reduced earlier than chlorophyll fluorescence and the amount of chlorophyll in susceptible plants. In the glyphosate-resistant biotype, stomatal conductance was the only parameter slightly affected only 5 days post-application. In susceptible plants, the initial glyphosate effects on gas exchange could be a response to a feedback regulation of photosynthesis. Since the herbicide affects actively growing tissues regardless of the inhibition of photosynthesis, the demand of assimilates decreased and consequently induced an accumulation of carbohydrates in leaves. We concluded that stomatal conductance could be a very sensitive parameter to assess both the susceptibility/resistance to glyphosate before the phytotoxic symptoms become evident.

  12. Glyphosate inhibits rust diseases in glyphosate-resistant wheat and soybean

    OpenAIRE

    Feng, Paul C. C.; Baley, G. James; Clinton, William P.; Bunkers, Greg J.; Alibhai, Murtaza F.; Timothy C. Paulitz; Kidwell, Kimberlee K.

    2005-01-01

    Glyphosate is a broad-spectrum herbicide used for the control of weeds in glyphosate-resistant crops. Glyphosate inhibits 5-enolpyruvyl shikimate 3-phosphate synthase, a key enzyme in the synthesis of aromatic amino acids in plants, fungi, and bacteria. Studies with glyphosate-resistant wheat have shown that glyphosate provided both preventive and curative activities against Puccinia striiformis f. sp. tritici and Puccinia triticina, which cause stripe and leaf rusts, respectively, in wheat. ...

  13. Glyphosate inhibits rust diseases in glyphosate-resistant wheat and soybean

    OpenAIRE

    Feng, Paul C. C.; Baley, G. James; Clinton, William P.; Bunkers, Greg J.; Alibhai, Murtaza F.; Paulitz, Timothy C.; Kidwell, Kimberlee K.

    2005-01-01

    Glyphosate is a broad-spectrum herbicide used for the control of weeds in glyphosate-resistant crops. Glyphosate inhibits 5-enolpyruvyl shikimate 3-phosphate synthase, a key enzyme in the synthesis of aromatic amino acids in plants, fungi, and bacteria. Studies with glyphosate-resistant wheat have shown that glyphosate provided both preventive and curative activities against Puccinia striiformis f. sp. tritici and Puccinia triticina, which cause stripe and leaf rusts, respectively, in wheat. ...

  14. 75 FR 24969 - Glyphosate From China

    Science.gov (United States)

    2010-05-06

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Glyphosate From China AGENCY: United States International Trade Commission. ACTION: Notice of... gives notice that its antidumping investigation concerning glyphosate from China (investigation No. 731...

  15. THE REMOVAL OF GLYPHOSATE FROM DRINKING WATER

    Science.gov (United States)

    The effectiveness of granulated activated carbon (GAC), packed activated carbon (PAC), conventional treatment, membranes, and oxidation for removing glyphosate from natural waters is evaluated. Results indicate that GAC and PAC are not effective in removing glyphosate, while oxid...

  16. 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.

  17. Crop Response to Glyphosate Trimesium Sulphosate

    Directory of Open Access Journals (Sweden)

    Danijela PAVLOVIC

    2013-12-01

    Full Text Available Glyphosate may cause injury to non-target plants. The first detectable symptom after glyphosate treatment is the growth inhibition, followed by noticeable yellowing (chlorosis of the treated tissue. Five to ten days after the treatment, the chlorosis turns into necrosis and the plants begin to die. Greenhouse research was conducted in 2007 to investigate the response of glyphosate resistant (GR soybeans PAN 520 line and non-glyphosate resistant EGRET line of soybeans to glyphosate trimesium sulphosate and to evaluate soybeans injury to help in weed resistance detection. The methods used to detect changes were dose response test, HPLC measurement based on glyphosate induced accumulation of shikimate, and morpho-anatomical changes (light and electron microscopy. Damaged chloroplasts are a clear indication of a glyphosate injury. If the injury rating is related to increased shikimate levels, there is greater certainty that differences among biotypes are due to glyphosate tolerance.

  18. THE REMOVAL OF GLYPHOSATE FROM DRINKING WATER

    Science.gov (United States)

    The effectiveness of granulated activated carbon (GAC), packed activated carbon (PAC), conventional treatment, membranes, and oxidation for removing glyphosate from natural waters is evaluated. Results indicate that GAC and PAC are not effective in removing glyphosate, while oxid...

  19. Modeling intraindividual variability with repeated measures data methods and applications

    CERN Document Server

    Hershberger, Scott L

    2013-01-01

    This book examines how individuals behave across time and to what degree that behavior changes, fluctuates, or remains stable.It features the most current methods on modeling repeated measures data as reported by a distinguished group of experts in the field. The goal is to make the latest techniques used to assess intraindividual variability accessible to a wide range of researchers. Each chapter is written in a ""user-friendly"" style such that even the ""novice"" data analyst can easily apply the techniques.Each chapter features:a minimum discussion of mathematical detail;an empirical examp

  20. A quick telemanipulator calibration and repeatability method with applications

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, J.F.; Haley, D.C. [Oak Ridge National Lab., TN (United States). Robotics & Process Systems Div.

    1994-09-01

    This paper will present a methodology that was used to calibrate and measure the repeatability of two telemanipulators at Oak Ridge National Laboratory. The global accuracy of the method was 0.05 in. ({approx_equal} 1.3 mm), and the orientation accuracy was approximately 6 min ({approx_equal} 0.002 rads). For most teleoperator systems, these accuracies are more than adequate because of the construction of the mechanism and sensor capabilities (e.g., typically 12 bits of resolution). Although industrial robots require accuracies of about 0.05 mm or better, telemanipulators do not.

  1. Effects of glyphosate on brachypodium distachyon

    OpenAIRE

    Altıntaş, Ayşegul; Altintas, Aysegul

    2010-01-01

    Glyphosate is a non-selective herbicide used widely as the most popular weed management tool, especially since the commercialization of glyphosate-resistant crops. Due to overuse, several weed species have evolved resistance towards glyphosate and this trend threatens the future of world food production. Brachypodium distachyon has been proposed as a model organism specifically for economically important crops such as wheat and barley. Thus, evaluating the effects of glyphosate on Brachypodiu...

  2. Glyphosate: too much of a good thing?

    OpenAIRE

    Marek eCuhra; Thomas eBøhn; Petr eCuhra

    2016-01-01

    Although previously accepted as the less toxic alternative, with low impact on animals, farmers as well as consumers who are exposed to residues in food, glyphosate chemicals are now increasingly controversial as new evidence from research is emerging. We argue that specific aspects of the history, chemistry and safety of glyphosate and glyphosate-based herbicides should be thoroughly considered in present and future re-evaluations of these dominant agrochemicals:· Glyphosate is not a si...

  3. Co-expression of G2-EPSPS and glyphosate acetyltransferase GAT genes conferring high tolerance to glyphosate in soybean

    OpenAIRE

    Bingfu eGuo; Yong eGuo; Huilong eHong; Longguo eJin; Lijuan eZhang; Ru-Zhen eChang; Wei eLu; Min eLin; Li-Juan eQiu

    2015-01-01

    Glyphosate is a widely used non-selective herbicide with broad spectrum of weed control around the world. At present, most of the commercial glyphosate tolerant soybeans utilize glyphosate tolerant gene CP4-EPSPS or glyphosate acetyltransferase gene GAT separately. In this study, both glyphosate tolerant gene G2-EPSPS and glyphosate degraded gene GAT were co-transferred into soybean and transgenic plants showed high tolerance to glyphosate. Molecular analysis including PCR, Sothern blot, qRT-...

  4. 76 FR 27268 - Glyphosate; Pesticide Tolerance

    Science.gov (United States)

    2011-05-11

    ... AGENCY 40 CFR Part 180 Glyphosate; Pesticide Tolerance AGENCY: Environmental Protection Agency (EPA... glyphosate in or on corn, field, forage. Monsanto Company requested this tolerance under the Federal Food... tolerance for residues of the herbicide glyphosate, N-(phosphonomethyl) glycine, in or on corn, field...

  5. Applications of inter simple sequence repeat (ISSR) rDNA in ...

    African Journals Online (AJOL)

    Applications of inter simple sequence repeat (ISSR) rDNA in detecting ... and phylogenetic relationships between Lymnaea natalensis collected from Giza, ... in water samples of all tested governorates with different significant differences.

  6. Occurrence and fate of the herbicide glyphosate and its degradate aminomethylphosphonic acid in the atmosphere

    Science.gov (United States)

    Chang, Feng-Chih; Simcik, M.F.; Capel, P.D.

    2011-01-01

    This is the first report on the ambient levels of glyphosate, the most widely used herbicide in the United States, and its major degradation product, aminomethylphosphonic acid (AMPA), in air and rain. Concurrent, weekly integrated air particle and rain samples were collected during two growing seasons in agricultural areas in Mississippi and Iowa. Rain was also collected in Indiana in a preliminary phase of the study. The frequency of glyphosate detection ranged from 60 to 100% in both air and rain. The concentrations of glyphosate ranged from 3 and from glyphosate in air were similar or greater to those of the other high-use herbicides observed in the Mississippi River basin, whereas its concentration in rain was greater than the other herbicides. It is not known what percentage of the applied glyphosate is introduced into the air, but it was estimated that up to 0.7% of application is removed from the air in rainfall. Glyphosate is efficiently removed from the air; it is estimated that an average of 97% of the glyphosate in the air is removed by a weekly rainfall ≥30 mm.

  7. Physiological effects of the herbicide glyphosate on the cyanobacterium Microcystis aeruginosa.

    Science.gov (United States)

    Wu, Liang; Qiu, Zhihao; Zhou, Ya; Du, Yuping; Liu, Chaonan; Ye, Jing; Hu, Xiaojun

    2016-09-01

    Glyphosate has been used extensively for weed control in agriculture in many countries. However, glyphosate can be transported into the aquatic environment and might cause adverse effects on aquatic life. This study investigated the physiological characteristics of cyanobacteria Microcystis aeruginosa (M. aeruginosa) after exposure to glyphosate, and the results showed that changes in cell density production, chlorophyll a and protein content are consistent. In M. aeruginosa, oxidative stress caused by glyphosate indicated that 48h of exposure increased the concentration of malondialdehyde (MDA) and enhanced the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). To further investigate the toxicity of glyphosate on M. aeruginosa, the viability of treated cells was monitored and the toxin release was determined. The results indicated that glyphosate induced apoptosis of and triggered toxin release in M. aeruginosa. These results are helpful for understanding the toxic effects of glyphosate on cyanobacteria, which is important for environmental assessment and protection. These results are also useful for guidance on the application of this type of herbicide in agricultural settings.

  8. Effects of glyphosate and endosulfan on soil microorganisms in soybean crop Efeitos do endosulfan e glyphosate sobre microrganismos do solo na cultura da soja

    Directory of Open Access Journals (Sweden)

    J.L. Pereira

    2008-01-01

    Full Text Available Transgenic soybean, resistant to glyphosate, is the most dominant transgenic crop grown commercially in the world. Research works on herbicide and insecticide mixtures and their effects on microorganisms are rarely reported. This work aimed to study the impact of glyphosate, endosulfan and their mixtures on the microbial soil activity in soybean crop. The experiment was carried out in a complete randomized block design with four treatments and five replications. The treatments were glyphosate 480 SL [540 g of active ingredient (a.i. ha-1], endosulfan 350 EC (525 g a.i. ha-1, the glyphosate 480 SL [540 g of active ingredient (a.i. ha-1] mixed with endosulfan 350 EC (525 g a.i. ha-1 and the control. Microbial activity was evaluated five days after treatment application. Glyphosate application was not an impacting factor for soil CO2 production. Endosulfan application (alone or mixed with glyphosate suppressed CO2 production by microorganisms in the soil. Microbial biomass and microbial quotient were lower in the treatments using endosulfan alone and in those using endosulfan mixed with glyphosate than in the treatments using glyphosate alone and control.A soja resistente ao glyphosate é a cultura transgênica mais cultivada em todo o mundo. Pesquisas envolvendo o impacto de mistura de herbicidas e inseticidas e seus efeitos sobre microrganismos do solo são raramente reportadas. Este trabalho teve por objetivo avaliar o impacto do herbicida (glyphosate, do inseticida (endosulfan e da mistura de ambos sobre a atividade microbiana do solo na cultura da soja. O delineamento experimental foi em blocos casualizados, com quatro tratamentos e cinco repetições. Os tratamentos foram o herbicida glyphosate 480 SL [540 g de ingrediente ativo (i.a. ha-1], endosulfan 350 EC (525 g i.a. ha-1, a mistura de glyphosate 480 SL (540 g de i.a. ha-1 com endosulfan 350 EC (525 g i.a. ha-1 e a testemunha onde se aplicou água. A atividade microbiana foi avaliada aos

  9. Bayesian Concordance Correlation Coefficient with Application to Repeatedly Measured Data

    Directory of Open Access Journals (Sweden)

    Atanu BHATTACHARJEE

    2015-10-01

    Full Text Available Objective: In medical research, Lin's classical concordance correlation coefficient (CCC is frequently applied to evaluate the similarity of the measurements produced by different raters or methods on the same subjects. It is particularly useful for continuous data. The objective of this paper is to propose the Bayesian counterpart to compute CCC for continuous data. Material and Methods: A total of 33 patients of astrocytoma brain treated in the Department of Radiation Oncology at Malabar Cancer Centre is enrolled in this work. It is a continuous data of tumor volume and tumor size repeatedly measured during baseline pretreatment workup and post surgery follow-ups for all patients. The tumor volume and tumor size are measured separately by MRI and CT scan. The agreement of measurement between MRI and CT scan is calculated through CCC. The statistical inference is performed through Markov Chain Monte Carlo (MCMC technique. Results: Bayesian CCC is found suitable to get prominent evidence for test statistics to explore the relation between concordance measurements. The posterior mean estimates and 95% credible interval of CCC on tumor size and tumor volume are observed with 0.96(0.87,0.99 and 0.98(0.95,0.99 respectively. Conclusion: The Bayesian inference is adopted for development of the computational algorithm. The approach illustrated in this work provides the researchers an opportunity to find out the most appropriate model for specific data and apply CCC to fulfill the desired hypothesis.

  10. Non-target-site glyphosate resistance in Conyza bonariensis is based on modified subcellular distribution of the herbicide.

    Science.gov (United States)

    Kleinman, Ziv; Rubin, Baruch

    2017-01-01

    Conyza spp. were the first broadleaf weeds reported to have evolved glyphosate resistance. Several mechanisms have been proposed for glyphosate resistance. In an effort to elucidate the mechanism of this resistance in Conyza bonariensis, possible target-site and non-target-site mechanisms were investigated in glyphosate-resistant (GR) C. bonariensis biotypes. Using differential glyphosate applications and analyses of shikimate accumulation, we followed the herbicide effect in different plant organs and monitored the herbicide's apparent mobility. We found high shikimate levels in the roots and young leaves of glyphosate-sensitive (GS) plants, regardless of the site of application, whereas in GR plants, shikimate accumulated mainly in treated young leaves. (14) C-glyphosate studies, however, revealed the expected source-to-sink translocation pattern in both GS and GR plants. Sequencing of the appropriate EPSPS DNA fragments of GR and GS plants revealed no alteration at the Pro106 position. These data support the hypothesis that the glyphosate resistance of our C. bonariensis GR biotypes is associated with altered subcellular distribution of glyphosate, which keeps the herbicide sequestered away from the EPSPS target site in the chloroplast. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  11. Glyphosate-resistant and conventional canola (Brassica napus L.) responses to glyphosate and Aminomethylphosphonic Acid (AMPA) treatment

    Science.gov (United States)

    Glyphosate-resistant (GR) canola expresses two transgenes: 1) the microbial glyphosate oxidase gene (gox) encoding the glyphosate oxidase enzyme (GOX) that metabolizes glyphosate to aminomethylphosphonic acid (AMPA) and 2) cp4 that encodes a GR form of the glyphosate target enzyme 5-enolpyruvylshiki...

  12. 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

    2014-07-01

    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.

  13. Uptake and toxicity of glyphosate in the lichen Xanthoria parietina (L.) Th. Fr.

    Science.gov (United States)

    Vannini, Andrea; Guarnieri, Massimo; Bačkor, Martin; Bilová, Ivana; Loppi, Stefano

    2015-12-01

    This study investigated if treatment of the lichen Xanthoria parietina (L.) Th. Fr. with glyphosate caused uptake of this herbicide as well as physiological alterations. Samples were treated with Glifene SL®, a common commercial glyphosate-based herbicide, at the lowest recommended doses (3.6g/L) as well as with doses slightly higher than the highest suggested (36 g/L). The results clearly showed glyphosate uptake in X. parietina proportionally to the dose provided. Adverse physiological effects were evident on the photosynthetic apparatus (photosynthetic efficiency, chlorophyll a content, chlorophyll degradation) as well as on the fungal respiration rates and cell membrane integrity (ergosterol content, dehydrogenase activity) already after 24h from treatment, also at the low application dose. It is concluded that lichens are suitable organisms for monitoring unwanted biological effects from the application of glyphosate-based herbicides, as well as for detecting the accumulation of this compound in the biota, thus screening for its environmental fate.

  14. Factors affecting the fate and transport of glyphosate and AMPA into surface waters of agricultural watersheds in the United States and Europe

    Science.gov (United States)

    Coupe, R.; Kalkhoff, S.; Capel, P.; Gregoire, C.

    2012-04-01

    Glyphosate [N-(phosphonomethyl)glycine] is a herbicide used extensively in almost all agricultural and urban areas of the United States and Europe. Although, glyphosate is used widely throughout the world in the production of many crops, it is predominately used in the United States on soybeans, corn, potatoes, and cotton that have been genetically modified to be tolerant to glyphosate. From 1992 to 2007, the agricultural use of glyphosate has increased from less than 10,000 Mg to more than 80,000 Mg, respectively. The greatest areal use is in the midwestern United States where glyphosate is applied on transgenic corn and soybeans. Because of the difficulty and expense in analyzing for glyphosate and AMPA (aminomethylphosphonic acid, a primary glyphosate degradate) in water, there have been only small scale studies on the fate and transport of glyphosate. The characterization of the transport of glyphosate and AMPA on a watershed scale is lacking. Glyphosate and AMPA were frequently detected in the surface waters of 4 agricultural watersheds in studies conducted by the U.S. Geological Survey in the United States and at the Laboratory of Hydrology and Geochemistry of Strasbourg. Two of these basins were located in the midwestern United States where the major crops are corn and soybean, the third is located the lower Mississippi River Basin where the major crops are soybean, corn, rice, and cotton, and the fourth was located near Strasbourg, France where the use of glyphosate was on a vineyard. The load as a percent of use ranged from 0.009 to 0.86 percent and could be related to 3 factors: source strength, hydrology, and flowpath. Glyphosate use in a watershed results in some occurrence in surface water at the part per billion level; however, those watersheds most at risk for the offsite transport of glyphosate are those with high application rates, rainfall that results in overland runoff, and a flowpath that does not include transport through the soil.

  15. Effects of repeated applications of fungicide carbendazim on its persistence and microbial community in soil

    Institute of Scientific and Technical Information of China (English)

    YU Yunlong; CHU Xiaoqiang; PANG Guohui; XIANG Yueqin; FANG Hua

    2009-01-01

    Carbendazim, a systemic benzimidazole fungicide, is applied repeatedly to control of plant diseases including soilborne diseases, over a growing season. Studies were carried out under laboratory conditions to assess the effects of repeated carbendazim applications on its persistence and microbial community in soil. The results indicate that dissipation of carbendazim in soil was accelerated with its application frequency. The degradation rate constant of carbendazim was increased significantly from 0.074 d-1 to 0.79 d-1. The corresponding half-life was shorten markedly from 9.3 d to 0.9 d after four repeated applications. No significant inhibitory effect of carbendazim on soil microbial utilization of the carbon sources was observed after first treatment, but a slight increase in average well color development (AWCD) was shown after second, third, and fourth applications. It suggested that soil microorganisms become adapted to carbendazim after repeated application. Simpson and Shannon indexes of soil microbial community from carbendazim treated soil were also similar to those from the control soil, indicating that the richness and dominant character of soil microorganisms remain unchangeable after repeated application. However, after first, second, and third addition of carbendazim, McIntosh indexes on day 21 were significantly increased as compared with the control, suggesting that balance of soil microorganisms was altered due to the enrichment of the specific carbendazim-adapting strains in soil.

  16. Soil Properties Control Glyphosate Sorption in Soils Amended with Birch Wood Biochar

    DEFF Research Database (Denmark)

    Kahawaththa Gamage, Inoka Damayanthi Kumari; Moldrup, Per; Paradelo, Marcos

    2016-01-01

    , Kd (L kg−1), of the herbicide glyphosate. We measured Kd in equilibrium batch sorption experiments with triplicate soil samples from 20 field plots that received biochar at different application rates (0 to 100 Mg ha−1). The results showed that pure biochar had a lower glyphosate Kd value as compared...... to soils. Yet, at the Kalundborg soils, the application of biochar enhanced the sorption of glyphosate when tested after 7–19 months of soil–biochar interaction. The relative enhancement effect on glyphosate sorption diminished with increasing biochar application rate, presumably due to increased mineral......–biochar interactions. In the Risoe soils, potential biochar effects on glyphosate sorption were affected by a distinct gradient in soil pH (7.4 to 8.3) and electrical conductivity (0.40–0.90 mS cm −1) resulting from a natural CaCO3 gradient. Thus, glyphosate Kd showed strong linear correlation with pH and EC...

  17. Fluorescence enhancement of CdTe/CdS quantum dots by coupling of glyphosate and its application for sensitive detection of copper ion

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhengqing; Liu Shaopu; Yin Pengfei [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); He Youqiu, E-mail: heyq@swu.edu.cn [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

    2012-10-01

    Graphical abstract: Glyphosate (Glyp) had been used to modify the surface of CdTe/CdS QDs, resulting in the enhancement of fluorescence intensity. The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu{sup 2+} based on the fluorescence quenching. Highlights: Black-Right-Pointing-Pointer Water soluble CdTe/CdS quantum dots capped with glyphosate were firstly synthesized. Black-Right-Pointing-Pointer The fluorescence of the Glyp-functionalized QDs was quenched by copper ion. Black-Right-Pointing-Pointer A new fluorescent sensor for copper ion was developed based on the prepared QDs. Black-Right-Pointing-Pointer The sensor exhibited high sensitivity and good selectivity for copper ion. - Abstract: A novel fluorescent probe for Cu{sup 2+} determination based on the fluorescence quenching of glyphosate (Glyp)-functionalized quantum dots (QDs) was firstly reported. Glyp had been used to modify the surface of QDs to form Glyp-functionalized QDs following the capping of thioglycolic acid on the core-shell CdTe/CdS QDs. Under the optimal conditions, the response was linearly proportional to the concentration of Cu{sup 2+} between 2.4 Multiplication-Sign 10{sup -2} {mu}g mL{sup -1} and 28 {mu}g mL{sup -1}, with a detection limit of 1.3 Multiplication-Sign 10{sup -3} {mu}g mL{sup -1} (3{delta}). The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu{sup 2+}. The fluorescent probe was successfully used for the determination of Cu{sup 2+} in environmental samples. The mechanism of reaction was also discussed.

  18. Behavioral responses of juvenile Daphnia magna after exposure to glyphosate and glyphosate-copper complexes.

    Science.gov (United States)

    Hansen, Lone Rykær; Roslev, Peter

    2016-10-01

    Glyphosate (N-(phosphonomethyl)glycine) is the active ingredient in a range of popular broad-spectrum herbicide formulations. Glyphosate is a chelating agent that can form stable complexes with divalent metal ions including Cu(II). Little is known about the bioavailability and ecotoxicity of glyphosate-Cu(II) complexes to aquatic organisms. In this study, we used video tracking and behavior analysis to investigate sublethal effects of binary mixtures of glyphosate and Cu(II) to juvenile D. magna. Behavioral responses were quantified for individual D. magna after 24h and 48h exposure to glyphosate and glyhosate-Cu(II) mixtures. Sublethal concentrations resulted in decreases in swimming velocity, acceleration speed, and distance moved whereas inactive time of D. magna increased. Distance moved and inactive time were the most responsive parameters to glyphosate and glyphosate-Cu(II) exposure. On a molar basis, glyphosate-Cu(II) complexes appeared more toxic to D. magna than glyphosate alone. The 48h EC50 for glyphosate and glyphosate-Cu(II) determined from swimming distance were 75.2μM and 8.4μM, respectively. In comparison, traditional visual observation of mobility resulted in 48h EC50 values of 52.8μM and 25.5μM for glyphosate and glyphosate-Cu(II), respectively. The behavioral responses indicated that exposure of D. magna to mixtures of glyphosate and Cu(II) attenuated acute metal toxicity but increased apparent glyphosate toxicity due to complexation with Cu(II). The study suggests that glyphosate is a likely mediator of aquatic metal toxicity, and that video tracking provides an opportunity for quantitative studies of sublethal effects of pesticide complexes. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Glyphosate sobre a resistência à ferrugem (Puccinia psidii do eucalipto Glyphosate on eucalyptus resistance to rust (Puccinia psidii

    Directory of Open Access Journals (Sweden)

    L.D. Tuffi Santos

    2007-03-01

    ça. Conclui-se que o glyphosate não afetou a resistência do eucalipto a Puccinia psidii, ocorrendo diminuição da severidade da doença em plantas expostas ao glyphosate via deriva, e que existe tolerância diferencial entre os clones ao herbicida.Glyphosate is the herbicide most applied on eucalyptus plantations for weed control, acting directly on the shikimic acid pathway, the main via for the formation of compounds connected with the natural defenses of the plant, such as lignin, salicytic acid and phytoalexins. Thus, glyphosate contact with the leaves of the plant through drift may have important consequences for disease resistance. The aim of our research was to evaluate glyphosate drift involvement with severity of rust caused by Puccinia psidii in genotypes with different levels of resistance to the pathogen, after inoculation in a controlled environment. Seedlings of four clones, two heterozygote clones resistant to rust (UFV01 and UFV02 and two homozygote clones susceptible to rust (UFV03 and UFV04 were submitted to sub-doses of 0 (control; 28.8, 57.6, 86.4 and 115.2 g ha-1 of glyphosate simulating drift. Three days after glyphosate application, the plants were inoculated with UFV01 isolated from P. psidii obtained from Eucalyptus grandis in the Itapetininga region. On day 21 after inoculation, the following parameters were evaluated: rust intensity, by means of a diagrammatic scale with four classes of severity (SO and S2 resistant to rust and S2 and S3 susceptible to rust, number of pustules per leaf area, area affected by rust, average number of urediniospores cm-2, glyphosate percentage intoxication, and average number of urediniospores/pustule. Clone UFV04 was found to be the most susceptible while UFV01 was the most tolerant to the herbicide. Drift did not change the level of resistance to rust with respect to the resistant genotypes (UFV01 and UFV02 which presented no pustule both in plants exposed to drift and control plants. Susceptibility was maintained

  20. Agricultural impacts of glyphosate-resistant soybean cultivation in South America.

    Science.gov (United States)

    Cerdeira, Antonio L; Gazziero, Dionsio L P; Duke, Stephen O; Matallo, Marcus B

    2011-06-08

    In the 2009/2010 growing season, Brazil was the second largest world soybean producer, followed by Argentina. Glyphosate-resistant soybeans (GRS) are being cultivated in most of the soybean area in South America. Overall, the GRS system is beneficial to the environment when compared to conventional soybean. GRS resulted in a significant shift toward no-tillage practices in Brazil and Argentina, but weed resistance may reduce this trend. Probably the highest agricultural risk in adopting GRS in Brazil and South America is related to weed resistance due to use of glyphosate. Weed species in GRS fields have shifted in Brazil to those that can more successfully withstand glyphosate or to those that avoid the time of its application. Five weed species, in order of importance, Conyza bonariensis (L.) Cronquist, Conyza canadensis (L.) Cronquist, Lolium multiflorum Lam., Digitaria insularis (L.) Mez ex Ekman, and Euphorbia heterophylla L., have evolved resistance to glyphosate in GRS in Brazil. Conyza spp. are the most difficult to control. A glyphosate-resistant biotype of Sorghum halepense L. has evolved in GRS in Argentina and one of D. insularis in Paraguay. The following actions are proposed to minimize weed resistance problem: (a) rotation of GRS with conventional soybeans in order to rotate herbicide modes of action; (b) avoidance of lower than recommended glyphosate rates; (c) keeping soil covered with a crop or legume at intercrop intervals; (d) keeping machinery free of weed seeds; and (d) use of a preplant nonselective herbicide plus residuals to eliminate early weed interference with the crop and to minimize escapes from later applications of glyphosate due to natural resistance of older weeds and/or incomplete glyphosate coverage.

  1. GLYPHOSATE REMOVAL FROM DRINKING WATER

    Science.gov (United States)

    Activated-carbon, oxidation, conventional-treatment, filtration, and membrane studies are conducted to determine which process is best suited to remove the herbicide glyphosate from potable water. Both bench-scale and pilot-scale studies are completed. Computer models are used ...

  2. GLYPHOSATE REMOVAL FROM DRINKING WATER

    Science.gov (United States)

    Activated-carbon, oxidation, conventional-treatment, filtration, and membrane studies are conducted to determine which process is best suited to remove the herbicide glyphosate from potable water. Both bench-scale and pilot-scale studies are completed. Computer models are used ...

  3. Glyphosate effects on photosynthesis, nutrient accumulation, and nodulation in glyphosate-resistant soybean.

    Science.gov (United States)

    Previous studies demonstrated that the photosynthesis of some cultivars of first (GR1) and second generation (GR2) glyphosate-resistant soybean was reduced by glyphosate. The reduction in photosynthesis caused by glyphosate might affect nutrient uptake and lead to lower plant biomass production and ...

  4. Ecological risk assessment for aquatic organisms from over-water uses of glyphosate.

    Science.gov (United States)

    Solomon, Keith R; Thompson, Dean G

    2003-01-01

    Although the herbicide glyphosate is most widely used in agriculture, some is used for the control of emergent aquatic weeds in ditches, wetlands, and margins of water bodies, largely as the formulation Rodeo. This article presents an ecological risk assessment (ERA) of glyphosate and some of the recommended surfactants as used in or near aquatic systems. Glyphosate does not bioaccumulate, biomagnify, or persist in a biologically available form in the environment. Its mechanism of action is specific to plants and it is relatively nontoxic to animals. As a commercial product, glyphosate may be formulated with surfactants that increased efficacy but, in some cases, are more toxic to aquatic organisms than the parent material. For this risk assessment, three model exposure scenarios--static or low-flow systems such as ponds, flowing waters such as streams, and systems subjected to tidal flows such as estuaries--were chosen and application rates from 1 to 8 kg glyphosate/ha were modeled. Additional measured exposure data from several field studies were also used. As acute exposures are most likely to occur, acute toxicity data were used as effect measures for the purposes of risk assessment. Toxicity data were obtained from the literature and characterized using probabilistic techniques. Risk assessments based on estimated and measured concentrations of glyphosate that would result from its use for the control of undesirable plants in wetlands and over-water situations showed that the risk to aquatic organisms is negligible or small at application rates less than 4 kg/ha and only slightly greater at application rates of 8 kg/ha. Less is known about the environmental fate and toxicology of the surfactants commonly used in combination with the Rodeo formulation of glyphosate. The surfactants used for this purpose were judged not to be persistent nor bioaccumulative in the environment. Distributional analysis of measured deposition concentrations of LI 700, suggest that

  5. The role of L-type amino acid transporters in the uptake of glyphosate across mammalian epithelial tissues.

    Science.gov (United States)

    Xu, Jiaqiang; Li, Gao; Wang, Zhuoyi; Si, Luqin; He, Sijie; Cai, Jialing; Huang, Jiangeng; Donovan, Maureen D

    2016-02-01

    Glyphosate is one of the most commonly used herbicides worldwide due to its broad spectrum of activity and reported low toxicity to humans. Glyphosate has an amino acid-like structure that is highly polar and shows low bioavailability following oral ingestion and low systemic toxicity following intravenous exposures. Spray applications of glyphosate in agricultural or residential settings can result in topical or inhalation exposures to the herbicide. Limited systemic exposure to glyphosate occurs following skin contact, and pulmonary exposure has also been reported to be low. The results of nasal inhalation exposures, however, have not been evaluated. To investigate the mechanisms of glyphosate absorption across epithelial tissues, the permeation of glyphosate across Caco-2 cells, a gastrointestinal epithelium model, was compared with permeation across nasal respiratory and olfactory tissues excised from cows. Saturable glyphosate uptake was seen in all three tissues, indicating the activity of epithelial transporters. The uptake was shown to be ATP and Na(+) independent, and glyphosate permeability could be significantly reduced by the inclusion of competitive amino acids or specific LAT1/LAT2 transporter inhibitors. The pattern of inhibition of glyphosate permeability across Caco-2 and nasal mucosal tissues suggests that LAT1/2 play major roles in the transport of this amino-acid-like herbicide. Enhanced uptake into the epithelial cells at barrier mucosae, including the respiratory and gastrointestinal tracts, may result in more significant local and systemic effects than predicted from glyphosate's passive permeability, and enhanced uptake by the olfactory mucosa may result in further CNS disposition, potentially increasing the risk for brain-related toxicities.

  6. Glyphosate-Resistant Goosegrass from Mississippi

    OpenAIRE

    Vijay K. Nandula; Wright, Alice A.; Molin, William T.

    2013-01-01

    A suspected glyphosate-resistant goosegrass [Eleusine indica (L.) Gaertn.] population, found in Washington County, Mississippi, was studied to determine the level of resistance and whether the resistance was due to a point mutation, as was previously identified in a Malaysian population. Whole plant dose response assays indicated a two- to four-fold increase in resistance to glyphosate. Leaf disc bioassays based on a glyphosate-dependent increase in shikimate levels indicated a five- to eight...

  7. Glyphosate drift promotes changes in fitness and transgene gene flow in canola (Brassica napus) and hybrids

    Science.gov (United States)

    Londo, Jason P.; Bautista, Nonnatus S.; Sagers, Cynthia L.; Lee, E. Henry; Watrud, Lidia S.

    2010-01-01

    Background and Aims With the advent of transgenic crops, genetically modified, herbicide-resistant Brassica napus has become a model system for examining the risks and potential ecological consequences of escape of transgenes from cultivation into wild compatible species. Escaped transgenic feral B. napus and hybrids with compatible weedy species have been identified outside of agriculture and without the apparent selection for herbicide resistance. However, herbicide (glyphosate) exposure can extend beyond crop field boundaries, and a drift-level of herbicide could function as a selective agent contributing to increased persistence of transgenes in the environment. Methods The effects of a drift level (0·1 × the field application rate) of glyphosate herbicide and varied levels of plant competition were examined on plant fitness-associated traits and gene flow in a simulated field plot, common garden experiment. Plants included transgenic, glyphosate-resistant B. napus, its weedy ancestor B. rapa, and hybrid and advanced generations derived from them. Key Results The results of this experiment demonstrate reductions in reproductive fitness for non-transgenic genotypes and a contrasting increase in plant fitness for transgenic genotypes as a result of glyphosate-drift treatments. Results also suggest that a drift level of glyphosate spray may influence the movement of transgenes among transgenic crops and weeds and alter the processes of hybridization and introgression in non-agronomic habitats by impacting flowering phenology and pollen availability within the community. Conclusions The results of this study demonstrate the potential for persistence of glyphosate resistance transgenes in weedy plant communities due to the effect of glyphosate spray drift on plant fitness. Additionally, glyphosate drift has the potential to change the gene-flow dynamics between compatible transgenic crops and weeds, simultaneously reducing direct introgression into weedy species

  8. The rise and future of glyphosate and glyphosate-resistant crops.

    Science.gov (United States)

    Green, Jerry M

    2016-10-18

    Glyphosate and glyphosate-resistant crops had a revolutionary impact on weed management practices, but the epidemic of glyphosate-resistant (GR) weeds is rapidly decreasing the value of these technologies. In areas that fully adopted glyphosate and GR crops, GR weeds evolved and glyphosate and glyphosate traits now must be combined with other technologies. The chemical company solution is to combine glyphosate with other chemicals, and the seed company solution is to combine glyphosate resistance with other traits. Unfortunately, companies have not discovered a new commercial herbicide mode-of-action for over 30 years and have already developed or are developing traits for all existing herbicide types with high utility. Glyphosate mixtures and glyphosate trait combinations will be the mainstays of weed management for many growers, but are not going to be enough to keep up with the capacity of weeds to evolve resistance. Glufosinate, auxin, HPPD-inhibiting and other herbicide traits, even when combined with glyphosate resistance, are incremental and temporary solutions. Herbicide and seed businesses are not going to be able to support what critics call the chemical and transgenic treadmills for much longer. The long time without the discovery of a new herbicide mode-of-action and the epidemic of resistant weeds is forcing many growers to spend much more to manage weeds and creating a worst of times, best of times predicament for the crop protection and seed industry. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  9. Glyphosate degradation in glyphosate-resistant and -susceptible crops and weeds.

    Science.gov (United States)

    Duke, Stephen O

    2011-06-08

    High levels of aminomethylphosphonic acid (AMPA), the main glyphosate metabolite, have been found in glyphosate-treated, glyphosate-resistant (GR) soybean, apparently due to plant glyphosate oxidoreductase (GOX)-like activity. AMPA is mildly phytotoxic, and under some conditions the AMPA accumulating in GR soybean correlates with glyphosate-caused phytotoxicity. A bacterial GOX is used in GR canola, and an altered bacterial glyphosate N-acetyltransferase is planned for a new generation of GR crops. In some weed species, glyphosate degradation could contribute to natural resistance. Neither an isolated plant GOX enzyme nor a gene for it has yet been reported in plants. Gene mutation or amplification of plant genes for GOX-like enzyme activity or horizontal transfer of microbial genes from glyphosate-degrading enzymes could produce GR weeds. Yet, there is no evidence that metabolic degradation plays a significant role in evolved resistance to glyphosate. This is unexpected, considering the extreme selection pressure for evolution of glyphosate resistance in weeds and the difficulty in plants of evolving glyphosate resistance via other mechanisms.

  10. The DRPLA CAG repeats in an Italian population sample: evaluation of the polymorphism for forensic applications.

    Science.gov (United States)

    Pelotti, S; Mantovani, V; Esposti, P D; D'Apote, L; Bragliani, M; Maiolini, E; Abbondanza, A; Pappalardo, G

    1998-03-01

    The DRPLA CAG repeats polymorphism has been studied in an Italian population sample. PCR amplification, manual PAGE and silver staining were employed. A total of 16 different alleles, spanning the range from 5 to 21 CAG triplettes, was observed. The heterozygosity was 0.81 and no significant deviation from Hardy-Weinberg equilibrium was found 81 meioses from parentage testing were also analyzed and a Mendelian pattern of inheritance was observed in all cases. In addition, we could successfully type DRPLA locus in some forensic specimens, 1 ng of DNA allowing clear definition of alleles. The authors conclude that the DRPLA CAG repeats analysis may be useful for forensic applications.

  11. Glyphosate-Degrading Microorganisms from Industrial Activated Sludge

    OpenAIRE

    Balthazor, Terry M.; Hallas, Laurence E.

    1986-01-01

    A plating medium was developed to isolate N-phosphonomethylglycine (glyphosate)-degrading microorganisms, with glyphosate as the sole phosphorus source. Two industrial biosystems treating glyphosate wastes contained elevated microbial counts on the medium. One purified isolate metabolized glyphosate to aminomethylphosphonic acid, mineralizing this accumulating intermediate during log growth. This microorganism has been identified as a Flavobacterium species.

  12. Development and application of a liquid chromatography-mass spectrometry method to evaluate the glyphosate and aminomethylphosphonic acid dissipation in maize plants after foliar treatment.

    Science.gov (United States)

    Bernal, José; Martin, María T; Soto, María E; Nozal, María J; Marotti, Ilaria; Dinelli, Giovanni; Bernal, José L

    2012-04-25

    A simple and fast method has been developed and validated to measure glyphosate (GLYP) and aminomethylphosphonic acid (AMPA), which were previously derivatized with 9-fluorenylmethylchloroformate (FMOC-Cl), in maize plants using liquid chromatography (LC) coupled to fluorescence (FLD) and electrospray ionization mass spectrometry (ESI-MS) detection. The method has shown to be consistent, reliable, precise, and efficient. Moreover, the limits of detection (LOD) and quantification (LOQ) reached with the proposed method for GLYP and AMPA are lower than the established maximum residue levels (MRLs). The validated method was applied to quantify GLYP and AMPA in genetically modified (GM) maize foliar treated with the herbicide. It has been found that the GLYP dissipation was mainly due to the progressive dilution effect after herbicide treatment. Finally, it was also observed that the GLYP residue dissipation trend in maize shoot (leaves and stem) tissue determined by LC-ESI-MS matched that determined by liquid scintillation.

  13. Rapid degradation of bensulfuron-methyl upon repeated application in paddy soils

    Institute of Scientific and Technical Information of China (English)

    XIE Xiao-mei; LIU Wei-ping; ABID Subhani

    2004-01-01

    Rapid degradation of bensulfuron-methyl upon repeated application in paddy soils was studied. The results showed that the DT50of bensulfuron-methyl was reduced from 16 d to 9 d in soil with one-year bensulfuron-methyl application. Rapid bensulfuron-methyl degradation was happened to previously untreated soil by addition 5% rapid bensuifuron-methyl adapted soil and was inhibited following pre-treatment with broad-spectrum antibiotic chloramphenicol. In bensulfuron-methyl adapted soil mineralisation of 14C labeled bensulfuronmethyl to 14 CO2 occurred at a faster rate than with previously untreated soil. It was concluded that rapid bensulfuron-methyl degradation upon repeated application is probably linked to the adaptation of soil bacteria which can utilize bensulfuron-methyl as a source of carbon and energy.

  14. Evaluation of spectrophotometric and HPLC methods for shikimic acid determination in plants: models in glyphosate-resistant and -susceptible crops.

    Science.gov (United States)

    Zelaya, Ian A; Anderson, Jennifer A H; Owen, Micheal D K; Landes, Reid D

    2011-03-23

    Endogenous shikimic acid determinations are routinely used to assess the efficacy of glyphosate in plants. Numerous analytical methods exist in the public domain for the detection of shikimic acid, yet the most commonly cited comprise spectrophotometric and high-pressure liquid chromatography (HPLC) methods. This paper compares an HPLC and two spectrophotometric methods (Spec 1 and Spec 2) and assesses the effectiveness in the detection of shikimic acid in the tissues of glyphosate-treated plants. Furthermore, the study evaluates the versatility of two acid-based shikimic acid extraction methods and assesses the longevity of plant extract samples under different storage conditions. Finally, Spec 1 and Spec 2 are further characterized with respect to (1) the capacity to discern between shikimic acid and chemically related alicyclic hydroxy acids, (2) the stability of the chromophore (t1/2), (3) the detection limits, and (4) the cost and simplicity of undertaking the analytical procedure. Overall, spectrophotometric methods were more cost-effective and simpler to execute yet provided a narrower detection limit compared to HPLC. All three methods were specific to shikimic acid and detected the compound in the tissues of glyphosate-susceptible crops, increasing exponentially in concentration within 24 h of glyphosate application and plateauing at approximately 72 h. Spec 1 estimated more shikimic acid in identical plant extract samples compared to Spec 2 and, likewise, HPLC detection was more effective than spectrophotometric determinations. Given the unprecedented global adoption of glyphosate-resistant crops and concomitant use of glyphosate, an effective and accurate assessment of glyphosate efficacy is important. Endogenous shikimic acid determinations are instrumental in corroborating the efficacy of glyphosate and therefore have numerous applications in herbicide research and related areas of science as well as resolving many commercial issues as a consequence of

  15. Eficácia de glyphosate em plantas de cobertura Efficacy of glyphosate in cover crops

    Directory of Open Access Journals (Sweden)

    P.C. Timossi

    2006-09-01

    Full Text Available Objetivou-se comparar a eficácia de três dosagens do herbicida glyphosate para a dessecação de Brachiaria decumbens, B. brizantha cv. Marandu e vegetação espontânea, visando a adoção do sistema plantio direto. Utilizou-se delineamento experimental de blocos ao acaso, num esquema fatorial 3 x 3, com quatro repetições. Testaram-se três tipos de cobertura vegetal e três dosagens de glyphosate (1,44, 2,16 e 2,88 kg ha-1. Aos 7, 14, 21 e 28 dias após a aplicação (DAA, foram feitas avaliações visuais da porcentagem de controle das coberturas vegetais e, aos 45 DAA, avaliações visuais da porcentagem de reinfestação da área. Conclui-se que, para as espécies que compunham a vegetação espontânea, o uso de 1,44 kg ha-1 proporcionou bom controle, sem no entanto evitar rebrotes de Digitaria insularis. Para as braquiárias, a mesma taxa de controle foi observada a partir de 2,16 kg ha-1. A camada de palha das braquiárias sobre o solo não foi capaz de suprimir a emergência de Cyperus rotundus, Alternanthera tenella, Raphanus raphanistrum, Bidens pilosa e Euphorbia heterophylla.This work aimed to compare rates of glyphosate to desiccate Brachiaria decumbens, B. brizantha cv. Marandu and spontaneous plants (weeds, aiming to adopt the no-tillage system. A randomized block experimental design in a factorial scheme was used (3x3, with four replications. The factors consisted of three species of cover crops and three rates of glyphosate (1.44, 2.16 and 2.88 kg ha-1. At 7, 14, 21 and 28 days after application of the herbicide, visual evaluations of the percentage of cover crop control were carried out and at 45 days of the reinfestation percentage of the area. It was concluded that the spontaneous plants presented a good control at 1.44 kg ha-1, without, however, preventing Digitaria insularis sprouts. The same control rate starting at 2.16 kg ha-1 was observed for the Brachiaria species. The straw layer of these cover crops on the soil

  16. 75 FR 17768 - Glyphosate From China

    Science.gov (United States)

    2010-04-07

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Glyphosate From China AGENCY: United States International Trade Commission. ACTION: Institution of... United States is materially retarded, by reason of imports from China of glyphosate, provided for in...

  17. Bioremediation of glyphosate-contaminated soils.

    Science.gov (United States)

    Ermakova, Inna T; Kiseleva, Nina I; Shushkova, Tatyana; Zharikov, Mikhail; Zharikov, Gennady A; Leontievsky, Alexey A

    2010-09-01

    Based on the results of laboratory and field experiments, we performed a comprehensive assessment of the bioremediation efficiency of glyphosate-contaminated soddy-podzol soil. The selected bacterial strains Achromobacter sp. Kg 16 (VKM B-2534D) and Ochrobactrum anthropi GPK 3 (VKM B-2554D) were used for the aerobic degradation of glyphosate. They demonstrated high viability in soil with the tenfold higher content of glyphosate than the recommended dose for the single in situ treatment of weeds. The strains provided a two- to threefold higher rate of glyphosate degradation as compared to indigenous soil microbial community. Within 1-2 weeks after the strain introduction, the glyphosate content of the treated soil decreased and integral toxicity and phytotoxicity diminished to values of non-contaminated soil. The decrease in the glyphosate content restored soil biological activity, as is evident from a more than twofold increase in the dehydrogenase activity of indigenous soil microorganisms and their biomass (1.2-fold and 1.6-fold for saprotrophic bacteria and fungi, respectively). The glyphosate-degrading strains used in this study are not pathogenic for mammals and do not exhibit integral toxicity and phytotoxicity. Therefore, these strains are suitable for the efficient, ecologically safe, and rapid bioremediation of glyphosate-contaminated soils.

  18. Resposta de biótipos de Euphorbia heterophylla a doses de glyphosate Response of Euphorbia heterophylla biotypes to glyphosate rates

    Directory of Open Access Journals (Sweden)

    L Vargas

    2011-01-01

    Full Text Available A leiteira (Euphorbia heterophylla é uma planta daninha de ciclo anual encontrada com frequência em lavouras de soja na região Sul do Brasil, controlada em lavouras de soja geneticamente modificada (Roundup Ready® - RR com uso do herbicida glyphosate. Entretanto, nos últimos anos, o controle dessa espécie não tem sido satisfatório em alguns locais, provocando a suspeita de que foram selecionados biótipos resistentes ao herbicida. Diante disso, o objetivo deste trabalho foi avaliar, por meio de curvas de dose-resposta, biótipos de leiteira com suspeita de resistência ao glyphosate. O experimento foi realizado em casa de vegetação, em delineamento experimental completamente casualizado, com quatro repetições. Os tratamentos constituíram-se de doses crescentes de glyphosate (0, 90, 180, 360, 720, 1.080, 1.440 e 2.160 g e.a. ha-1, aplicadas sobre cinco biótipos de leiteira, oriundos de lavouras de soja RR do Estado do Rio Grande do Sul. As variáveis avaliadas foram controle e matéria seca da parte aérea. Os resultados evidenciam que os biótipos de leiteira avaliados são suscetíveis ao glyphosate.Wild poinsettia is an annual cycle weed, commonly found in soybean crop in southern Brazil. It is controlled by glyphosate in genetically- modified soybean (Roundup Ready® - RR. The control of this species has not proven to be satisfactory in some places in the last years, leading to the suspicion that biotypes resistant to glyphosate have been selected. The objective this work was to evaluate, by response-dose curve, wild poinsettia biotypes with suspected resistance to glyphosate. The experiment was conducted under greenhouse conditions and the experiment was arranged in a randomized complete block design, with four replications. The treatments consisted of increased application rates of glyphosate (0, 90, 180, 360, 720, 1,080, 1,440 and 2,160 g a.e. ha-1 on five wild poinsettia biotypes, from crop soybean RR in the state of Rio

  19. Effect of formulation and repeated applications on the enantioselectivity of metalaxyl dissipation and leaching in soil.

    Science.gov (United States)

    Celis, Rafael; Gámiz, Beatriz; Adelino, María A; Cornejo, Juan; Hermosín, María C

    2015-11-01

    Soil incubation and column leaching experiments were conducted to address the question of whether the type of formulation (unsupported versus clay supported) and repeated applications of the chiral fungicide (RS)-metalaxyl affected the enantioselectivity of its dissipation and leaching in a slightly alkaline, loamy sand agricultural soil. Regardless of the type of formulation and the number of fungicide applications, the R-enantiomer of metalaxyl was degraded faster than the S-enantiomer, but the individual degradation rates of R- and S-metalaxyl were highly affected by the different application regimes assayed (t1/2 = 2-104 days). Repeated applications accelerated the degradation of the biologically active R-metalaxyl enantiomer, whereas they led to slower degradation of the non-active S-metalaxyl enantiomer. The type of formulation had less influence on the dissipation rates of the enantiomers. For all formulations tested, soil column leachates became increasingly enriched in S-enantiomer as the number of fungicide applications was increased, and application of metalaxyl to soil columns as clay-based formulations reduced the leaching of both enantiomers. Pesticide application conditions can greatly influence the enantioselective dissipation of chiral pesticides in soil, and hence are expected to exert a great impact on both the biological efficacy and the environmental chiral signatures of pesticides applied as mixtures of enantiomers or racemates to agricultural soils. © 2014 Society of Chemical Industry.

  20. Glyphosate: too much of a good thing?

    Directory of Open Access Journals (Sweden)

    Marek eCuhra

    2016-04-01

    Full Text Available Although previously accepted as the less toxic alternative, with low impact on animals, farmers as well as consumers who are exposed to residues in food, glyphosate chemicals are now increasingly controversial as new evidence from research is emerging. We argue that specific aspects of the history, chemistry and safety of glyphosate and glyphosate-based herbicides should be thoroughly considered in present and future re-evaluations of these dominant agrochemicals:· Glyphosate is not a single chemical, it is a family of compounds with different chemical, physical and toxicological properties.· Glyphosate is increasingly recognized as having more profound toxicological effects than assumed from previous assessments.· Global use of glyphosate is continuously increasing and residues are detected in food, feed and drinking water. Thus, consumers are increasingly exposed to higher levels of glyphosate residues, and from an increasing number of sources.· Glyphosate regulation is predominantly still based on primary safety-assessment testing in various indicator organisms. However, archive studies indicate fraud and misbehavior committed by the commercial laboratories providing such research.We see emerging evidences from studies in test-animals, ecosystems indicators and studies in human health, which justify stricter regulatory measures. This implies revising glyphosate residue definitions and lowering Maximum Residue Limits (MRLs permissible in biological material intended for food and feed, as well as strengthening environmental criteria such as accepted residue concentrations in surface waters.It seems that although recent research indicates that glyphosates are less harmless than previously assumed and have complex toxicological potential, still regulatory authorities accept industry demands for approving higher levels of these residues in food and feed.

  1. [Clustered regularly interspaced short palindromic repeats: structure, function and application--a review].

    Science.gov (United States)

    Cui, Yujun; Li, Yanjun; Yan, Yanfeng; Yang, Ruifu

    2008-11-01

    CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats), the basis of spoligotyping technology, can provide prokaryotes with heritable adaptive immunity against phages' invasion. Studies on CRISPR loci and their associated elements, including various CAS (CRISPR-associated) proteins and leader sequences, are still in its infant period. We introduce the brief history', structure, function, bioinformatics research and application of this amazing immunity system in prokaryotic organism for inspiring more scientists to find their interest in this developing topic.

  2. Improving Glyphosate Oxidation Activity of Glycine Oxidase from Bacillus cereus by Directed Evolution

    Science.gov (United States)

    Zhan, Tao; Zhang, Kai; Chen, Yangyan; Lin, Yongjun; Wu, Gaobing; Zhang, Lili; Yao, Pei; Shao, Zongze; Liu, Ziduo

    2013-01-01

    Glyphosate, a broad spectrum herbicide widely used in agriculture all over the world, inhibits 5-enolpyruvylshikimate-3-phosphate synthase in the shikimate pathway, and glycine oxidase (GO) has been reported to be able to catalyze the oxidative deamination of various amines and cleave the C-N bond in glyphosate. Here, in an effort to improve the catalytic activity of the glycine oxidase that was cloned from a glyphosate-degrading marine strain of Bacillus cereus (BceGO), we used a bacteriophage T7 lysis-based method for high-throughput screening of oxidase activity and engineered the gene encoding BceGO by directed evolution. Six mutants exhibiting enhanced activity toward glyphosate were screened from two rounds of error-prone PCR combined with site directed mutagenesis, and the beneficial mutations of the six evolved variants were recombined by DNA shuffling. Four recombinants were generated and, when compared with the wild-type BceGO, the most active mutant B3S1 showed the highest activity, exhibiting a 160-fold increase in substrate affinity, a 326-fold enhancement in catalytic efficiency against glyphosate, with little difference between their pH and temperature stabilities. The role of these mutations was explored through structure modeling and molecular docking, revealing that the Arg51 mutation is near the active site and could be an important residue contributing to the stabilization of glyphosate binding, while the role of the remaining mutations is unclear. These results provide insight into the application of directed evolution in optimizing glycine oxidase function and have laid a foundation for the development of glyphosate-tolerant crops. PMID:24223901

  3. Linker-assisted immunoassay and liquid chromatography/mass spectrometry for the analysis of glyphosate

    Science.gov (United States)

    Lee, E.A.; Zimmerman, L.R.; Bhullar, B.S.; Thurman, E.M.

    2002-01-01

    A novel, sensitive, linker-assisted enzyme-linked immunosorbent assay (L'ELISA) was compared to on-line solidphase extraction (SPE) with high-performance liquid chromatography/mass spectrometry (HPLC/MS) for the analysis of glyphosate in surface water and groundwater samples. The L'ELISA used succinic anhydride to derivatize glyphosate, which mimics the epitotic attachment of glyphosate to horseradish peroxidase hapten. Thus, L'ELISA recognized the derivatized glyphosate more effectively (detection limit of 0.1 ??g/L) and with increased sensitivity (10-100 times) over conventional ELISA and showed the potential for other applications. The precision and accuracy of L'ELISA then was compared with on-line SPE/HPLC/MS, which detected glyphosate and its degradate derivatized with 9-fluorenylmethyl chloroformate using negative-ion electrospray (detection limit 0.1 ??g/L, relative standard deviation ??15%). Derivatization efficiency and matrix effects were minimized by adding an isotope-labeled glyphosate (2-13C15N). The accuracy of L'ELISA gave a false positive rate of 18% between 0.1 and 1.0 ??g/L and a false positive rate of only 1% above 1.0 ??g/L. The relative standard deviation was ??20%. The correlation of L'ELISA and HPLC/MS for 66 surface water and groundwater samples was 0.97 with a slope of 1.28, with many detections of glyphosate and its degradate in surface water but not in groundwater.

  4. Evaluating exposure and potential effects on honeybee brood (Apis mellifera) development using glyphosate as an example.

    Science.gov (United States)

    Thompson, Helen M; Levine, Steven L; Doering, Janine; Norman, Steve; Manson, Philip; Sutton, Peter; von Mérey, Georg

    2014-07-01

    This study aimed to develop an approach to evaluate potential effects of plant protection products on honeybee brood with colonies at realistic worst-case exposure rates. The approach comprised 2 stages. In the first stage, honeybee colonies were exposed to a commercial formulation of glyphosate applied to flowering Phacelia tanacetifolia with glyphosate residues quantified in relevant matrices (pollen and nectar) collected by foraging bees on days 1, 2, 3, 4, and 7 postapplication and glyphosate levels in larvae were measured on days 4 and 7. Glyphosate levels in pollen were approximately 10 times higher than in nectar and glyphosate demonstrated rapid decline in both matrices. Residue data along with foraging rates and food requirements of the colony were then used to set dose rates in the effects study. In the second stage, the toxicity of technical glyphosate to developing honeybee larvae and pupae, and residues in larvae, were then determined by feeding treated sucrose directly to honeybee colonies at dose rates that reflect worst-case exposure scenarios. There were no significant effects from glyphosate observed in brood survival, development, and mean pupal weight. Additionally, there were no biologically significant levels of adult mortality observed in any glyphosate treatment group. Significant effects were observed only in the fenoxycarb toxic reference group and included increased brood mortality and a decline in the numbers of bees and brood. Mean glyphosate residues in larvae were comparable at 4 days after spray application in the exposure study and also following dosing at a level calculated from the mean measured levels in pollen and nectar, showing the applicability and robustness of the approach for dose setting with honeybee brood studies. This study has developed a versatile and predictive approach for use in higher tier honeybee toxicity studies. It can be used to realistically quantify exposure of colonies to pesticides to allow the

  5. Dissipation of antibiotics in three different agricultural soils after repeated application of biosolids.

    Science.gov (United States)

    Yang, Lu; Wu, Longhua; Liu, Wuxing; Huang, Yujuan; Luo, Yongming; Christie, Peter

    2016-11-21

    Application of biosolids to agricultural soils is one of the pathways by which antibiotics can be introduced into agricultural ecosystems. A pot experiment was conducted with repeated soil amendment with biosolids to examine the concentrations of four classes of antibiotics (tetracyclines, sulfonamides, fluoroquinolones, and macrolides) and their dissipation in three different soil types in wheat-rice rotations. Antibiotics accumulate in the soils after repeated application of biosolids. Fluoroquinolones showed stronger accumulation and persistence in the test soils than the other three classes of antibiotics. The maximum residual antibiotic concentration was that of norfloxacin at 155 ± 16 μg kg(-1) in the Typic Hapli-Stagnic Anthrosols (paddy soil). Predicted half-lives were up to 3.69 years, a much longer period than that between biosolid applications (twice each year on average). Antibiotic accumulation followed the rough order fluoroquinolones > tetracyclines > macrolides > sulfonamides, and the sulfonamides were seldom encountered. When biosolid application was suspended, the dissipation rate accelerated. Antibiotic dissipation was slightly slower when biosolids with high heavy metal concentrations were applied and microbial degradation may have been the main mechanism of dissipation. Norfloxacin persistence was positively correlated with its soil adsorption capacity. Cation exchange capacity and soil organic matter content may have vital roles in the soil adsorption of fluoroquinolones. Because of their persistence, the fluoroquinolones must be taken into account in the planning of biosolid applications in agricultural practice.

  6. Gene flow from glyphosate-resistant crops.

    Science.gov (United States)

    Mallory-Smith, Carol; Zapiola, Maria

    2008-04-01

    Gene flow from transgenic glyphosate-resistant crops can result in the adventitious presence of the transgene, which may negatively impact markets. Gene flow can also produce glyphosate-resistant plants that may interfere with weed management systems. The objective of this article is to review the gene flow literature as it pertains to glyphosate-resistant crops. Gene flow is a natural phenomenon not unique to transgenic crops and can occur via pollen, seed and, in some cases, vegetative propagules. Gene flow via pollen can occur in all crops, even those that are considered to be self-pollinated, because all have low levels of outcrossing. Gene flow via seed or vegetative propagules occurs when they are moved naturally or by humans during crop production and commercialization. There are many factors that influence gene flow; therefore, it is difficult to prevent or predict. Gene flow via pollen and seed from glyphosate-resistant canola and creeping bentgrass fields has been documented. The adventitious presence of the transgene responsible for glyphosate resistance has been found in commercial seed lots of canola, corn and soybeans. In general, the glyphosate-resistant trait is not considered to provide an ecological advantage. However, regulators should consider the examples of gene flow from glyphosate-resistant crops when formulating rules for the release of crops with traits that could negatively impact the environment or human health.

  7. The toxicity of glyphosate alone and glyphosate-surfactant mixtures to western toad (Anaxyrus boreas) tadpoles.

    Science.gov (United States)

    Vincent, Kim; Davidson, Carlos

    2015-12-01

    Pesticide choice based on toxicity to nontarget wildlife is reliant on available toxicity data. Despite a number of recent studies examining the effects of glyphosate on amphibians, very few have aimed to understand the toxicological effects of glyphosate in combination with surfactants as it is commonly applied in the field. Land managers interested in making pesticide choices based on minimizing impacts to nontarget wildlife are hindered by a lack of published toxicity data. Short-term acute toxicity trials were conducted for glyphosate in the form of isopropylamine salt (IPA) alone and mixed with 2 surfactants: Agri-dex and Competitor with western toad (Anaxyrus [Bufo] boreas) tadpoles. Glyphosate IPA mixed with Competitor was 6 times more toxic than glyphosate IPA mixed with Agri-dex, and both mixtures were more toxic than glyphosate IPA alone. The median lethal concentrations reported for 24-h and 48-h exposures were 8279 mg/L (24 h) and 6392 mg/L (48 h) for glyphosate IPA alone; 5092 mg/L (24 h) and 4254 mg/L (48 h) for glyphosate IPA mixed with Agri-dex; and 853 mg/L (24 h) and 711 mg/L (48 h) for glyphosate IPA mixed with Competitor. The present study indicates that the toxicity of a tank mix may be greatly increased by the addition of surfactants and may vary widely depending on the specific surfactant.

  8. 草甘膦原粉母液处理的探讨%Discussion on Treatment of Glyphosate Mother Liquor

    Institute of Scientific and Technical Information of China (English)

    陈元群; 卢孙荣; 林庆才

    2013-01-01

      用过氧化氢氧化还原双甘膦制备草甘膦后,提取草甘膦原粉,对剩余草甘膦母液的处理条件进行摸索,进而提高草甘膦的生产收率,增加草甘膦母液的利用途径。%Glyphosate was prepared from N-(phosphonomethyl)iminodiacetic acid (PMIDA) by hydrogen peroxide oxidation and reduction reaction. The treatment conditions of glyphosate mother liquor were investigated in order to increase the production yield of glyphosate and expand the application of glyphosate mother liquor.

  9. Corneal epithelial toxicity of antiglaucoma formulations: in vitro study of repeated applications

    Directory of Open Access Journals (Sweden)

    Meloni M

    2012-09-01

    Full Text Available Marisa Meloni,1 Giampiero Cattaneo,2 Barbara De Servi11VitroScreen In Vitro Research Laboratories, 2Thea Farma, Milan, ItalyBackground: By using a biologically relevant and sensitive three-dimensional model of human corneal epithelium and multiple endpoint analysis, assessment of the potential for eye irritation and long-term compatibility of four registered ophthalmological preparations, ie, Timolabak®, Timoptol®, Nyogel®, and Timogel®, was performed. This approach enables classification of the potential for irritation, discriminating between mildly irritant and non-irritant ocular substances.Methods: The exposure protocol included two time periods, ie, 24 hours (acute application and 72 hours (repeated applications twice daily. This approach allows assessment of not only the acute reaction but also possible recovery, as well as mimicking the potential cumulative effects associated with long-term application. Using benzalkonium chloride (BAK 0.01% as a positive control, the following parameters were quantified: cellular viability by MTT test, histological analysis by hematoxylin and eosin staining, passive release of interleukin-1a by enzyme-linked immunosorbent assay, and OCLN gene expression by quantitative real-time polymerase chain reaction.Results: Cell viability was reduced to under the 50% cutoff value after acute exposure (24 hours to BAK 0.01%, and after repeated application (72 hours of Timoptol and Nyogel. Histological analysis after acute exposure showed signs of superficial damage with all formulations, and severe changes after repeated applications of Timoptol, BAK 0.01%, and Nyogel. Timolabak and Timogel did not significantly alter the morphology of the human corneal epithelial cells after the different exposure times. Interleukin-1α release was greater than that for the negative control (>20 pg/mL and the positive control (BAK 0.01%, Nyogel, and Timoptol treatments and not different after treatment with Timolabak and

  10. Dynamics of soil bacterial communities in response to repeated application of manure containing sulfadiazine.

    Directory of Open Access Journals (Sweden)

    Guo-Chun Ding

    Full Text Available Large amounts of manure have been applied to arable soils as fertilizer worldwide. Manure is often contaminated with veterinary antibiotics which enter the soil together with antibiotic resistant bacteria. However, little information is available regarding the main responders of bacterial communities in soil affected by repeated inputs of antibiotics via manure. In this study, a microcosm experiment was performed with two concentrations of the antibiotic sulfadiazine (SDZ which were applied together with manure at three different time points over a period of 133 days. Samples were taken 3 and 60 days after each manure application. The effects of SDZ on soil bacterial communities were explored by barcoded pyrosequencing of 16S rRNA gene fragments amplified from total community DNA. Samples with high concentration of SDZ were analyzed on day 193 only. Repeated inputs of SDZ, especially at a high concentration, caused pronounced changes in bacterial community compositions. By comparison with the initial soil, we could observe an increase of the disturbance and a decrease of the stability of soil bacterial communities as a result of SDZ manure application compared to the manure treatment without SDZ. The number of taxa significantly affected by the presence of SDZ increased with the times of manure application and was highest during the treatment with high SDZ-concentration. Numerous taxa, known to harbor also human pathogens, such as Devosia, Shinella, Stenotrophomonas, Clostridium, Peptostreptococcus, Leifsonia, Gemmatimonas, were enriched in the soil when SDZ was present while the abundance of bacteria which typically contribute to high soil quality belonging to the genera Pseudomonas and Lysobacter, Hydrogenophaga, and Adhaeribacter decreased in response to the repeated application of manure and SDZ.

  11. Micromorfologia foliar na análise da fitotoxidez por glyphosate em Eucalyptus grandis Leaf micromorphology in the analysis of glyphosate toxicity in Eucalyptus grandis

    Directory of Open Access Journals (Sweden)

    L.D. Tuffi Santos

    2009-01-01

    reduced height of the plants exposed to Scout® and Roundup transorb®. Leaf surface characteristics were not affected by glyphosate application. However, the micromorphological damages occurred prior to the appearance of visible symptoms, and were observed on both faces of the epidermis, in all clones tested. Damages such as erosion and amorphous aspect of epicuticular waxes and infestation of fungal hyphae occurred, independently of the formulation used. The anatomical evaluation of the leaf surface effectively described the damages caused by glyphosate. The growth and intoxication data indicate Zapp QI® formulation as presenting the lowest risk to eucalypt culture, in relation to the undesirable herbicide drift effects.

  12. Influence of glyphosate on the copper dissolution in phosphate buffer

    Science.gov (United States)

    Coutinho, C. F. B.; Silva, M. O.; Machado, S. A. S.; Mazo, L. H.

    2007-01-01

    The electrochemical behavior of copper microelectrode in phosphate buffer in the presence of glyphosate was investigated by electrochemical techniques. It was observed that the additions of glyphosate in the phosphate buffer increased the anodic current of copper microelectrode and the electrochemical dissolution was observed. This phenomenon could be associated with the Cu(II) complexation by glyphosate forming a soluble complex. Physical characterization of the surface showed that, in absence of glyphosate, an insoluble layer covered the copper surface; on the other hand, in presence of glyphosate, it was observed a corroded copper surface with the formation of glyphosate complex in solution.

  13. Resistência de genótipos de soja ao herbicida glyphosate Resistance of soybean genotypes to glyphosate

    Directory of Open Access Journals (Sweden)

    E Matsuo

    2009-12-01

    were evaluated: plant intoxication, number of nodes at the main stem, plant height and dry mass. When evaluating plant intoxication either at four days after application (DAA of the herbicide and at 28 DAA, the conventional genotypes showed statistically higher averages, compared to the glyphosate-resistant genotypes (RR. In evaluations accomplished at 0 DAA or at 28 DAA under 0.0 g e.a. ha-1, the genotype responses were different for all characters under evaluation, except for the number of nodes at 28 DAA. These differences were attributed to the physiological and environmental effects or to the characteristics of the material itself. At other doses, the behavior of the RR genotypes was superior to that of the conventional ones. Taking into account all characters under evaluation, it can be stated that Valiosa RR, BCR945G110, BCR945G114, BCR892G132, BCR892G140, BCR1067G210, BCR1070G244 and M-SOY 8008RR behaved similarly for glyphosate resistance when subjected to doses up to 2.160 g e.a. ha-1 .

  14. Single versus repeated applications of CuO and Ag nanomaterials and their effect on soil microflora.

    Science.gov (United States)

    Schlich, Karsten; Beule, Lukas; Hund-Rinke, Kerstin

    2016-08-01

    Nanomaterials enter the terrestrial environment via the repeated application of sludge to soils over many years. The goal of this investigation was to compare the effects of CuO and Ag nanomaterials on soil microorganisms after a single application and after repeated applications ultimately resulting in the same test concentrations. The effect on soil microorganisms was determined using the ammonium oxidation (ISO 15685), enzymatic activity patterns (ISO 22939) and MicroResp™ tests on days 28, 56 and 84. The comparability of single and repeated applications of ion-releasing nanomaterials depended on the test endpoint and duration. No significant differences between single and repeated applications were observed when testing nitrifying microorganisms and exoenzymes, but differences were observed in the substrate-induced respiration test. The three test systems used together provide more comprehensive information about the impact of different nanomaterials on the soil microflora and its diversity.

  15. 核磁共振磷谱在有机化合物草甘膦合成过程中的监控%The Application of 31^P-NMR Spectrum in Monitoring the Synthesis of Glyphosate

    Institute of Scientific and Technical Information of China (English)

    赵黎黎; 王敏; 钟江春; 林吉柏

    2012-01-01

    The 31^P-NMR is one of important technologies of Nuclear magnetic resonance; it plays a very important role in the quality and quantity of compound in organic chemistry and monitoring the synthesis. The article makes a brief introduction for the tested method in the Synthesis of Glyphosate by 31^P-NMR to supply a reference for the application of NMR in the field of organic pesticide.%磷谱是核磁共振的一项重要应用,它在有机化学的定性、定量以及合成过程的监控实验中具有非常重要的作用。本文开发了利用核磁共振磷谱进行有机农药草甘磷部分合成过程监控的实验方法。为草甘膦质量控制和品质提升提供方法支持,同时为进一步扩大核磁共振在有机农药化合物研究领域中的应用提供参考。

  16. Non-target effects of repeated chlorothalonil application on soil nitrogen cycling: The key functional gene study.

    Science.gov (United States)

    Zhang, Manyun; Xu, Zhihong; Teng, Ying; Christie, Peter; Wang, Jun; Ren, Wenjie; Luo, Yongming; Li, Zhengao

    2016-02-01

    The widespread and increasing application of chlorothalonil (CTN) raises concerns about its non-target impacts, but little information is available on the effect of CTN on the key functional genes related to soil nitrogen (N) cycling, especially in the case of repeated applications. In the present study, a microcosm incubation was conducted to determine CTN residues and the impacts on the abundances of key functional genes related to N cycling after repeated CTN applications. The results demonstrated that repeated CTN applications at the recommended application rate and five times the recommended rate led to the accumulation of CTN residue in soil at concentrations of 5.59 and 78.79 mg kg(-1), respectively, by the end of incubation. Real time PCR (RT-PCR) revealed that repeated CTN applications had negative effects on the chiA and aprA gene abundances. There were significantly negative correlations between CTN residues and abundances of AOA and AOB genes. In addition, the abundances of key functional genes involved in soil denitrification were declined by repeated CTN applications with the sole exception of the nosZ gene. This study suggests that repeated CTN applications could lead to the accumulation of CTN residue and generate somewhat inconsistent and erratic effects on the abundances of key functional genes related to soil N cycling.

  17. Glyphosate e nitrgênio no controle de Brachiaria decumbens Stapf em capineiras estabelecidas Glyphosate and nitrogen in the control of Brachiaria decumbens Stapf in established elephant grass stocking piles

    Directory of Open Access Journals (Sweden)

    Joadil Gonçalves de Abreu

    2006-10-01

    Full Text Available O objetivo do experimento foi avaliar a eficiência de utilização do herbicida glyphosate associado com adubação nitrogenada no controle de Brachiaria decumbens Stapf em capineiras estabelecidas. O delineamento experimental foi em blocos casualizados, com dezessete tratamentos e três repetições. Os tratamentos foram arranjados em esquema fatorial 4 x 4 + 1, sendo quatro doses de glyphosate (0, 720, 1440 e 2160 g/ha/aplicação, quatro doses de nitrogênio (0, 75, 150 e 225 kg/ha/ano e um tratamento adicional (testemunha com capina. As aplicações do nitrogênio e glyphosate, nas respectivas doses, foram realizadas imediatamente após o corte do capim-elefante. A associação entre o herbicida glyphosate (2160 g/ha/aplicação e nitrogênio (225 kg/ha/ano foi eficiente no controle de capim-braquiária em capineiras estabelecidas. A aplicação do herbicida glyphosate (2160 g/ha/aplicação reduziu o tamanho do banco de sementes de capim-braquiária no solo em 64%.The objective of this experiment was to evaluate the efficiency of the use of the herbicide glyphosate associated with nitrogen fertilization in the control of Brachiaria decumbens Stapf in elephant grass stocking piles. The experimental design used was a randomized blocks with 17 treatments and three replications. The treatments were arranged in 4x4+1 factorial scheme, namely four doses of glyphosate (0, 720, 1440 e 2160 g/ha/application, four doses of nitrogen (0, 75, 150 e 225 kg/ha/ano and one additional treatment (control with a hoeing. The application of the nitrogen and glyphosate, in the respective doses were performed immediately after the cutting of elephant grass. The association between glyphosate (2160 g/ha/application and nitrogen (225 kg/ha/ano was efficient in the control brachiaria grass in established elephant grass stocking piles. The application of the glyphosate (2160 g/ha/application reduced the size of the bank of brachiaria grass seeds in the soil in 64%.

  18. Concerns over use of glyphosate-based herbicides and risks associated with exposures: a consensus statement.

    Science.gov (United States)

    Myers, John Peterson; Antoniou, Michael N; Blumberg, Bruce; Carroll, Lynn; Colborn, Theo; Everett, Lorne G; Hansen, Michael; Landrigan, Philip J; Lanphear, Bruce P; Mesnage, Robin; Vandenberg, Laura N; Vom Saal, Frederick S; Welshons, Wade V; Benbrook, Charles M

    2016-02-17

    The broad-spectrum herbicide glyphosate (common trade name "Roundup") was first sold to farmers in 1974. Since the late 1970s, the volume of glyphosate-based herbicides (GBHs) applied has increased approximately 100-fold. Further increases in the volume applied are likely due to more and higher rates of application in response to the widespread emergence of glyphosate-resistant weeds and new, pre-harvest, dessicant use patterns. GBHs were developed to replace or reduce reliance on herbicides causing well-documented problems associated with drift and crop damage, slipping efficacy, and human health risks. Initial industry toxicity testing suggested that GBHs posed relatively low risks to non-target species, including mammals, leading regulatory authorities worldwide to set high acceptable exposure limits. To accommodate changes in GBH use patterns associated with genetically engineered, herbicide-tolerant crops, regulators have dramatically increased tolerance levels in maize, oilseed (soybeans and canola), and alfalfa crops and related livestock feeds. Animal and epidemiology studies published in the last decade, however, point to the need for a fresh look at glyphosate toxicity. Furthermore, the World Health Organization's International Agency for Research on Cancer recently concluded that glyphosate is "probably carcinogenic to humans." In response to changing GBH use patterns and advances in scientific understanding of their potential hazards, we have produced a Statement of Concern drawing on emerging science relevant to the safety of GBHs. Our Statement of Concern considers current published literature describing GBH uses, mechanisms of action, toxicity in laboratory animals, and epidemiological studies. It also examines the derivation of current human safety standards. We conclude that: (1) GBHs are the most heavily applied herbicide in the world and usage continues to rise; (2) Worldwide, GBHs often contaminate drinking water sources, precipitation, and air

  19. Impact of phosphate on glyphosate uptake and toxicity in willow.

    Science.gov (United States)

    Gomes, Marcelo Pedrosa; Le Manac'h, Sarah Gingras; Moingt, Matthieu; Smedbol, Elise; Paquet, Serge; Labrecque, Michel; Lucotte, Marc; Juneau, Philippe

    2016-03-05

    Phosphate (PO4(3-)) has been shown to increase glyphosate uptake by willow, a plant species known for its phytoremediation potential. However, it remains unclear if this stimulation of glyphosate uptake can result in an elevated glyphosate toxicity to plants (which could prevent the use of willows in glyphosate-remediation programs). Consequently, we studied the effects of PO4(3-) on glyphosate uptake and toxicity in a fast growing willow cultivar (Salix miyabeana SX64). Plants were grown in hydroponic solution with a combination of glyphosate (0, 0.001, 0.065 and 1 mg l(-1)) and PO4(3-) (0, 200 and 400 mg l(-1)). We demonstrated that PO4(3-) fertilization greatly increased glyphosate uptake by roots and its translocation to leaves, which resulted in increased shikimate concentration in leaves. In addition to its deleterious effects in photosynthesis, glyphosate induced oxidative stress through hydrogen peroxide accumulation. Although it has increased glyphosate accumulation, PO4(3-) fertilization attenuated the herbicide's deleterious effects by increasing the activity of antioxidant systems and alleviating glyphosate-induced oxidative stress. Our results indicate that in addition to the glyphosate uptake, PO4(3-) is involved in glyphosate toxicity in willow by preventing glyphosate induced oxidative stress.

  20. 75 FR 20862 - Glyphosate From China

    Science.gov (United States)

    2010-04-21

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Glyphosate From China AGENCY: United States International Trade Commission. ACTION: Revised schedule for the subject investigation. DATES: Effective Date: April 16, 2010. FOR FURTHER INFORMATION...

  1. Apparent effects of glyphosate on alkaloid production in coca plants grown in Colombia.

    Science.gov (United States)

    Casale, John; Lydon, John

    2007-05-01

    During the routine analysis of coca leaf material from South America, alkaloids in Erythroxylum coca var. ipadu (ECVI) leaf samples from fields suspected of being treated with glyphosate were compared with those from non-treated E. coca var. ipadu and Erythroxylum novogranatense var. novogranatense (ENVN) plants. Cocaine levels in leaf tissue from non-treated ECVI and ENVN were 0.53+/-0.08% and 0.64+/-0.08% (w/w), respectively, whereas leaves from treated plants were nearly devoid of cocaine. Further analysis demonstrated the presence of several previously undescribed N-nortropane alkaloids, several of which were tentatively identified. The results suggest that applications of glyphosate to coca plants can have dramatic effects on the quantity and quality of alkaloids produced by surviving or subsequent leaves. The analytical data presented will be of value to forensic chemists who encounter illicit cocaine preparations containing alkaloids produced from coca plants treated with glyphosate.

  2. Design and Application of the Drying Process for Ammonium Glyphosate%草甘膦铵盐干燥过程的设计与应用

    Institute of Scientific and Technical Information of China (English)

    张柏青; 程榕; 杨阿三; 孙勤; 郑燕萍; 李俊

    2013-01-01

    [Aims] The aim was to design and establish an ammonium glyphosate drying system with the output of 2 tons per hour. [Methods] The spin flash dryer and cyclone dryer combined drying technology was selected by bench test. The spin flash dryer and cyclone dryer were designed, and the main structure parameters were determined. [Results] The drying system was run at the superficial gas velocity of 3.5 and 1.5 m/s, exhaust temperature of 60 and 80 ℃. The results showed that design was reasonable, the system was convenient to operate and had low enery levels. The design objectives were achieved. [Conclusions] This combined drying technology was suitable for drying the powder and granular materials which was easy to agglomerate, and had low requirement of moisture content.%[目的]设计建立2 t/h草甘膦铵盐干燥系统.[方法]通过小试试验选择旋转闪蒸与旋流相结合的组合干燥工艺用于草甘膦铵盐的干燥.对旋转闪蒸干燥机和旋流干燥机进行设计计算,确定主要的结构参数.[结果]运行结果表明:分别选取操作气速3.5、1.5 m/s,排气温度60、80℃,对旋转闪蒸干燥机和旋流干燥机进行设计是合理的,系统操作方便,能耗较低,达到了设计目标.[结论]该组合干燥工艺适合干燥过程中易结块、产品湿含量要求较低粉粒状物料的干燥.

  3. On the Applicability of Elastic Network Models for the Study of RNA CUG Trinucleotide Repeat Overexpansion.

    Directory of Open Access Journals (Sweden)

    Àlex L González

    Full Text Available Non-coding RNAs play a pivotal role in a number of diseases promoting an aberrant sequestration of nuclear RNA-binding proteins. In the particular case of myotonic dystrophy type 1 (DM1, a multisystemic autosomal dominant disease, the formation of large non-coding CUG repeats set up long-tract hairpins able to bind muscleblind-like proteins (MBNL, which trigger the deregulation of several splicing events such as cardiac troponin T (cTNT and insulin receptor's, among others. Evidence suggests that conformational changes in RNA are determinant for the recognition and binding of splicing proteins, molecular modeling simulations can attempt to shed light on the structural diversity of CUG repeats and to understand their pathogenic mechanisms. Molecular dynamics (MD are widely used to obtain accurate results at atomistic level, despite being very time consuming, and they contrast with fast but simplified coarse-grained methods such as Elastic Network Model (ENM. In this paper, we assess the application of ENM (traditionally applied on proteins for studying the conformational space of CUG repeats and compare it to conventional and accelerated MD conformational sampling. Overall, the results provided here reveal that ANM can provide useful insights into dynamic rCUG structures at a global level, and that their dynamics depend on both backbone and nucleobase fluctuations. On the other hand, ANM fail to describe local U-U dynamics of the rCUG system, which require more computationally expensive methods such as MD. Given that several limitations are inherent to both methods, we discuss here the usefulness of the current theoretical approaches for studying highly dynamic RNA systems such as CUG trinucleotide repeat overexpansions.

  4. Impacto do glyphosate associado com endossulfan e tebuconazole sobre microrganismos endossimbiontes da soja Impact of glyphosate associated with endosulphan and tebuconazole on the endosymbiotic microorganisms of the soybean

    Directory of Open Access Journals (Sweden)

    M.R. Reis

    2010-01-01

    ção micorrízica e a nodulação da da soja.The objective of this work was to evaluate the effects of glyphosate, in sequential applications, and its interaction with endosulphan + tebuconazole on mycorrhizal colonization, nodulation, and leaf concentrations of P and N of soybean plants. The experiment was conducted in the field in a Yellow-Red Argisol in the 2007/2008 crop year. Ten treatments were installed in split plots following a randomized block design with four replications. Endosulphan + tebuconazole application was done in the main plots, while the different methods of weed control in the sub-plots (unhoed control, hoed control, single application of glyphosate, sequential application of glyphosate, single application of fomesafen + fluazifop-p-butyl. Shoot and nodule dry matter, nodule number, mycorrhizal colonization, and N and P concentrations were evaluated when the soybean plants reached the R2 stage. Glyphosate and fomesafen + fluazifop-p-butyl did not cause reductions in nodule dry matter, except in the presence of endosulphan + tebuconazole. Glyphosate in sequential applications, in the absence of endosulphan + tebuconazole, promoted decreases in nodule number. Fomesafen + fluazifop-p-butyl and glyphosate in sequential applications negatively affected N concentrations in the leaves compared to the hoed control, in the absence of endosulphan + tebuconazole. Glyphosate did not affect the mycorrhizal colonization regardless of the application of endosulphan + tebuconazole. However, fomesafen + fluazifop-p-butyl led to increases in the mycorrhizal colonization in the absence of endosulphan + tebuconazole. Glyphosate applied sequentially on soybean plants, under the conditions studied, did not affect the mycorrhizal colonization and nodulation.

  5. Manejo de Conyza bonariensis resistente ao glyphosate: coberturas de inverno e herbicidas em pré-semeadura da soja Management of glyphosate resistant Conyza bonariensis: winter cover crops and herbicides in soybean pre-seeding

    Directory of Open Access Journals (Sweden)

    F.P. Lamego

    2013-06-01

    cover crops lopsided oat, radish, common vetch, Italian ryegrass, wheat, and fallow in the main plots, and in the subplots, the following burn-down treatments: glyphosate (720 g e.a ha-1, glyphosate (720 g e.a ha-1 + 2,4-D (1.050 g e.a ha-1, glyphosate (720 g e.a ha-1 + 2,4-D (1.050 g e.a ha‑1/paraquat (200 g i.a ha-1 + diuron (100 g i.a ha-1, glyphosate (720 g e.a ha-1 + chlorimuron-ethyl (80 g i.a ha-1, glyphosate (720 g e.a ha-1 + chlorimuron-ethyl (80 g i.a ha-1/paraquat (200 g i.a ha-1 + diuron (100 g i.a ha-1 and mowing. Radish was the cover crop species that produced the highest amount of shoot dry mass during the winter season, while common vetch had the highest suppressive effect on germination and initial development of C. bonariensis. Associations of glyphosate with 2,4-D or chlorimuron-ethyl, followed by the sequential application of paraquat + diuron, caused the highest reductions in C. bonariensis infestation.

  6. Optical detection of glyphosate in water

    Science.gov (United States)

    de Góes, R. E.; Possetti, G. R. C.; Muller, M.; Fabris, J. L.

    2017-04-01

    This work shows preliminary results of the detection of Glyphosate in water by using optical fiber spectroscopy. A colloid with citrate-caped silver nanoparticles was employed as substrate for the measurements. A cross analysis between optical absorption and inelastic scattering evidenced a controlled aggregation of the sample constituents, leading to the possibility of quantitative detection of the analyte. The estimate limit of detection for Glyphosate in water for the proposed sensing scheme was about 1.7 mg/L.

  7. Mechanism of glyphosate control of Phelipanche aegyptiaca.

    Science.gov (United States)

    Shilo, Tal; Zygier, Lilach; Rubin, Baruch; Wolf, Shmuel; Eizenberg, Hanan

    2016-11-01

    Despite its total reliance on its host plant, the holoparasite Phelipanche aegyptiaca suffers from a deficiency of aromatic amino acids upon exposure to glyphosate. The herbicide glyphosate inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), a key enzyme in the biosynthesis of aromatic amino acids. However, the functionality of the EPSPS pathway in the obligate root holoparasite Phelipanche aegyptiaca is not straightforward because of the parasite's total dependence on the host plant. Despite the importance of glyphosate as a means of controlling P. aegyptiaca, the mechanism of action of the herbicide in this parasite is not clearly understood. We characterized glyphosate control of P. aegyptiaca by using a glyphosate-resistant tomato (GRT) genotype as the host plant and evaluating the activity of EPSPS and the levels of free aromatic amino acids in the parasite. The viability of the parasite's tissues deteriorated within the first 40 h after treatment (HAT) with glyphosate. In parallel, shikimate accumulation in the parasite was first detected at 24 HAT and increased over time. However, shikimate levels in the GRT host did not increase, indicating that the host was indeed glyphosate tolerant. Free phenylalanine and tyrosine levels decreased by 48 HAT in the parasite, indicating a deficiency of aromatic amino acids. The use of GRT as the host enabled us to observe, in an in situ experimental system, both endogenous EPSPS inhibition and a deficiency of aromatic amino acids in the parasite. We thus provided evidence for the presence of an active EPSPS and aromatic amino acid biosynthesis pathway in P. aegyptiaca and pinpointed this pathway as the target of glyphosate action in this parasite.

  8. Glyphosate in German adults - Time trend (2001 to 2015) of human exposure to a widely used herbicide.

    Science.gov (United States)

    Conrad, André; Schröter-Kermani, Christa; Hoppe, Hans-Wolfgang; Rüther, Maria; Pieper, Silvia; Kolossa-Gehring, Marike

    2017-01-01

    The broadband herbicide glyphosate (N-[phosphonomethyl]-glycine) and its main metabolite aminomethylphosphonic acid (AMPA) were analyzed by GC-MS-MS in 24h-urine samples cryo-archived by the German Environmental Specimen Bank (ESB). Samples collected in 2001, 2003, 2005, 2007, 2009, 2011, 2012, 2013, 2014, and 2015 were chosen for this retrospective analysis. All urine samples had been provided by 20 to 29 years old individuals living in Greifswald, a city in north-eastern Germany. Out of the 399 analyzed urine samples, 127 (=31.8%) contained glyphosate concentrations at or above the limit of quantification (LOQ) of 0.1μg/L. For AMPA this was the case for 160 (=40.1%) samples. The fraction of glyphosate levels at or above LOQ peaked in 2012 (57.5%) and 2013 (56.4%) after having discontinuously increased from 10.0% in 2001. Quantification rates were lower again in 2014 and 2015 with 32.5% and 40.0%, respectively. The overall trend for quantifiable AMPA levels was similar. Glyphosate and AMPA concentrations in urine were statistically significantly correlated (spearman rank correlation coefficient=0.506, p≤0.001). Urinary glyphosate and AMPA levels tended to be higher in males. The possible reduction in exposure since 2013 indicated by ESB data may be due to changes in glyphosate application in agricultural practice. The ESB will continue monitoring internal exposures to glyphosate and AMPA for following up the time trend, elucidating inter-individual differences, and contributing to the ongoing debate on the further regulation of glyphosate-based pesticides. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

  9. New insights on glyphosate mode of action in nodular metabolism: Role of shikimate accumulation.

    Science.gov (United States)

    de María, Nuria; Becerril, José M; García-Plazaola, José I; Hernandez, Antonio; De Felipe, María R; Fernandez-Pascual, Mercedes

    2006-04-05

    The short-term effects of the herbicide glyphosate (1.25-10 mM) on the growth, nitrogen fixation, carbohydrate metabolism, and shikimate pathway were investigated in leaves and nodules of nodulated lupine plants. All glyphosate treatments decreased nitrogenase activity rapidly (24 h) after application, even at the lowest and sublethal dose used (1.25 mM). This early effect on nitrogenase could not be related to either damage to nitrogenase components (I and II) or limitation of carbohydrates supplied by the host plant. In fact, further exposure to increasing glyphosate concentrations (5 mM) and greater time after exposure (5 days) decreased nodule starch content and sucrose synthase (SS; EC 2.4.1.13) activity but increased sucrose content within the nodule. These effects were accompanied by a great inhibition of the activity of phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31). There were remarkable and rapid effects on the increase of shikimic and protocatechuic (PCA) acids in nodules and leaves after herbicide application. On the basis of the role of shikimic acid and PCA in the regulation of PEPC, as potent competitive inhibitors, this additional effect provoked by glyphosate on 5-enolpyruvylshikimic-3-phosphate synthase enzyme (EPSPS; EC 2.5.1.19) inhibition would divert most PEP into the shikimate pathway, depriving energy substrates to bacteroids to maintain nitrogen fixation. These findings provide a new explanation for the effectiveness of glyphosate as a herbicide in other plant tissues, for the observed differences in tolerance among species or cultivars, and for the transitory effects on glyphosate-resistant transgenic crops under several environmental conditions.

  10. Electrochemical degradation and mineralization of glyphosate herbicide.

    Science.gov (United States)

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

    2017-01-23

    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/PbO2 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 (C0 = 16.9 mg L(-1)) decreased up to 0.6 mg L(-1) when the optimal conditions were imposed (current intensity of 4.77A 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.

  11. Comparison of glyphosate and Roundup preparations influence on inorganic pyrophosphatase activity and available phosphorus content in sandy loam

    Directory of Open Access Journals (Sweden)

    Maciej Płatkowski

    2016-03-01

    Full Text Available The aim of the study was to compare the effect of glyphosate and its formulations: Roundup 360 SL (containing isopropylamine salt of glyphosate and polyethoxylated tallow amine and Roundup TransEnergy 450 SL (containing potassium salt of glyphosate and polyethoxylated ether amine on inorganic pyrophosphatase activity and available phosphorus content in soil. The experiment was carried out on loamy sand with organic carbon content 10.9 g·kg-1. Glyphosate and its salts amounts added to soil were: 0 (control, 1, 10, 100 mg·kg-1. Samples were adjusted to 60% maximum water capacity and they were incubated in temperature 20°C. Inorganic pyrophosphatase and available phosphorus content were measured on days 1, 7, 14, 28 and 56. The obtained results show that the observed effect of glyphosate and its formulations depended on the dosage and day of experiment. The largest changes of the measured parameters were observed after application of Roundup 360 SL – formulation containing glyphosate isopro­pylamine salt and polyethoxylated tallow amine. The positive statistically significant correlation between inorganic pyrophosphatase activity and available phosphorus content was reported only in soil treated with Roundup 360 SL.

  12. Mapping Proteome-wide Targets of Glyphosate in Mice.

    Science.gov (United States)

    Ford, Breanna; Bateman, Leslie A; Gutierrez-Palominos, Leilani; Park, Robin; Nomura, Daniel K

    2017-02-16

    Glyphosate, the active ingredient in the herbicide Roundup, is one of the most widely used pesticides in agriculture and home garden use. Whether glyphosate causes any mammalian toxicity remains highly controversial. While many studies have associated glyphosate with numerous adverse health effects, the mechanisms underlying glyphosate toxicity in mammals remain poorly understood. Here, we used activity-based protein profiling to map glyphosate targets in mice. We show that glyphosate at high doses can be metabolized in vivo to reactive metabolites such as glyoxylate and react with cysteines across many proteins in mouse liver. We show that glyoxylate inhibits liver fatty acid oxidation enzymes and glyphosate treatment in mice increases the levels of triglycerides and cholesteryl esters, likely resulting from diversion of fatty acids away from oxidation and toward other lipid pathways. Our study highlights the utility of using chemoproteomics to identify novel toxicological mechanisms of environmental chemicals such as glyphosate. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    African Journals Online (AJOL)

    USER

    2010-06-28

    Jun 28, 2010 ... comparative effects of glyphosate as carbon and/or phosphorus source on the growth of the isolates showed that ... hazardous effects of these chemicals on soil biological ... The removal of glyphosate from the environment.

  14. Repeated applications of photodynamic therapy on Candida glabrata biofilms formed in acrylic resin polymerized.

    Science.gov (United States)

    de Figueiredo Freitas, Lírian Silva; Rossoni, Rodnei Dennis; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos

    2017-04-01

    Previous studies have been suggested that photodynamic therapy (PDT) can be used as an adjuvant treatment for denture stomatitis. In this study, we evaluated the effects of multiple sessions of PDT on Candida glabrata biofilms in specimens of polymerized acrylic resin formed after 5 days. Subsequently, four applications of PDT were performed on biofilms in 24-h intervals (days 6-9). Also, we evaluated two types of PDT, including application of laser and methylene blue or light-emitting diode (LED) and erythrosine. The control groups were treated with physiological solution. The effects of PDT on biofilm were evaluated after the first and fourth application of PDT. The biofilm analysis was performed by counting the colony-forming units. The results showed that between the days 6 and 9, the biofilms not treated by PDT had an increase of 5.53 to 6.05 log (p = 0.0271). Regarding the treatments, after one application of PDT, the biofilms decreased from 5.53 to 0.89 log. When it was done four applications, the microbial reduction ranged from 6.05 log to 0.11 log. We observed that one application of PDT with laser or LED caused a reduction of 3.36 and 4.64 compared to the control groups, respectively (p = 0.1708). When it was done four applications of PDT, the reductions achieved were 1.57 for laser and 5.94 for LED (p = 0.0001). It was concluded that repeated applications of PDT on C. glabrata biofilms showed higher antimicrobial activity compared to single application. PDT mediated by LED and erythrosine was more efficient than the PDT mediated by laser and methylene blue.

  15. Repeated soil application of organic waste amendments reduces draught force and fuel consumption for soil tillage

    DEFF Research Database (Denmark)

    Peltrea, Clément; Nyord, Tavs; Bruun, Sander

    2015-01-01

    for different organic wastes influenced the specific draught. Overall, the decrease in draught force could lead to a decrease in tractor fuel consumption for soil tillage of up to 25% for compost applied at an accelerated rate and up to 14% for compost applied at a normal rate. This reduced fuel consumption......Abstract Soil application of organic waste products (OWP) can maintain or increase soil organic carbon (SOC) content, which in turn could lead to increased porosity and potentially to reduced energy use for soil tillage. Only a few studies have addressed the effect of SOC content on draught force...... for soil tillage, and this still needs to be addressed for fields that receive diverse types of organic waste of urban, agricultural and agro-industrial origin. The objective of this study was to determine the effect of changes in SOC induced by repeated soil application of OWP on draught force for soil...

  16. Development of sampling for quantification of glyphosate in natural waters

    OpenAIRE

    Tzaskos,Danilla Fernanda; Marcovicz,Crislaine; Dias,Nivea Maria Piccolomini; Rosso,Neiva Deliberali

    2012-01-01

    Glyphosate is a systemic, post-emergent, non-selective herbicide widely used in agriculture. The objective of this study was to develop a method for sample preparation, to partially purified natural water samples contaminated with residues of glyphosate, and to quantify them by derivation and spectroscopically. To assess the accuracy of the method, samples of water from an artesian well and from a stream were fortified with known amounts of glyphosate. The concentration of glyphosate was dete...

  17. 抗草甘膦杂草的抗性机理研究进展%Advances on Resistance Mechanism of Glyphosate-Resistant Weeds

    Institute of Scientific and Technical Information of China (English)

    巩元勇; 郭书巧; 束红梅; 王庆南; 倪万潮

    2012-01-01

    草甘膦因其独特而优异的理化特性,自上市起便受到广泛的关注,现在已经成为全世界应用最广的除草剂之一.但是随着草甘膦抗性杂草的不断出现,草甘膦的应用前景受到严峻的挑战.文章综述了草甘膦生产及应用现状、草甘膦作用机理和草甘膦抗性杂草的发展,重点阐述了草甘膦抗性杂草的抗性机理.最后对如何通过延缓草甘膦抗性杂草的出现,保护草甘膦提出建议.%Glyphosate, because of its unique and excellent physical and chemical properties, has attracted much attention since it was commercialized. At present, glyphosate has become one of the most widely used herbicide around the world. But with the emergence of glyphosate - resistant weeds population, the application prospect of glyphosate has been seriously challenged. In this paper it was reviewed in the production and application status, the mechanism of action of glyphosate and the development of glyphosate — resistant weeds especially focused on introduction of the resistance mechanism of glyphosate - resistant weeds. Finally, how to delay the emergence of glyphosate - resistant weeds to protect the application of glyphosate has been also proposed in this paper.

  18. Glyphosate and its formulations – Toxicity, occupational and environmental exposure

    Directory of Open Access Journals (Sweden)

    Marta Kwiatkowska

    2013-10-01

    Full Text Available Glyphosate (N-(phosphonomethylglycine is an active ingredient of the most widely used herbicide formulations in protecting agricultural and horticultural crops. Numerous results (mostly published in the years 2010-2013 concerning the action of glyphosate and its formulations in the recent decade were analyzed. Initial reports about alleged biodegradability of glyphosate in the environment turned out to be wrong. It has been shown that glyphosate remains in the soil and can reach people by spreading along with groundwater. Recent publications have shown that glyphosate is detected at low concentrations in the human blood. Publications cited in this article, which indicate a possible induction of neoplastic changes by glyphosate formulation, have raised great concern and controversy in the scientific world. Presenting adverse effects of glyphosate and its formulations we focused on the role of glyphosate formulations in hormonal disorders by impeding the expression of steroidogenic acute regulatory protein and the inhibition of aromatase activity. The impact of glyphosate on oxygen reactive species formation, changes in redox system and the effect on necrosis and apoptosis in various types of cells was shown. We also revealed that glyphosate as a phosphonate herbicide does not inhibit directly the activity of acetylcholinesterase. Based on numerous studies it was noted that commercial formulations of glyphosate exhibit higher toxicity than that of the active substance itself. The discussed problems clearly show the need to evaluate the toxicity of glyphosate and its formulations and related potential threat to humans. Med Pr 2013;64(5:717–729

  19. Exsudação radicular de glyphosate por Brachiaria decumbens e seus efeitos em plantas de eucalipto Radicular exudation of glyphosate by Brachiaria decumbens and its effects on eucalypt plant

    Directory of Open Access Journals (Sweden)

    L.D. Tuffi Santos

    2008-06-01

    weed and later, plant absorption. This study aimed to evaluate glyphosate exudation by Brachiaria decumbens and its effects on eucalypt plants when 14C-glyphosate, mixed to the solution of the commercial product Scout® was applied. Seedlings of two eucalypt clones (UFV05 and UFV06 were cultivated in pots, intercropped with Brachiaria decumbens, on two types of soil (clayey and sandy. At 35 days after transplantation, 50 µL of the mixture was applied on brachiaria by using a precision micro-syringe. After application, 2, 8, 16 and 24 days, samples of eucalypt plants were collected and fractioned in the primary apices, secondary apices, leaves and roots, following the usual methodology to determine radioactivity. Symptoms of intoxication were not observed in any eucalypt plant evaluation. However, 14C-glyphosate was found in all plants, regardless of the soil type, clone or evaluation time, with the highest concentration being found in the sandy soil. Results show radicular exudation of glyphosate by B. decumbens and its absorption by eucalypt plants through roots. However, concentrations lower than necessary may cause crop intoxication.

  20. Lack of transgene and glyphosate effects on mineral nutrition and amino acid content of glyphosate-resistant soybean

    Science.gov (United States)

    There has been controversy as to whether the glyphosate resistance gene and/or glyphosate applied to glyphosate-resistant (GR) soybean affect mineral content (especially Mg, Mn, and Fe), yield and amino acid content of GR soybean. A two-year field study (2013 and 2014) examined these questions at si...

  1. Impact of glyphosate-resistant sugar beet.

    Science.gov (United States)

    Morishita, Don W

    2016-12-19

    Glyphosate-resistant (GR) sugar beet became commercially available to US sugar beet growers in 2008 and was rapidly adopted. Prior to the availability of GR sugar beet, growers would commonly make 3-5 herbicide applications. This often resulted in some crop injury, but was accepted to reduce the impact of weeds. In addition, non-GR sugar beet was cultivated 1-3 times and often followed by hand weeding. The introduction of GR sugar beet drastically reduced the complexity of weed management. Concerns about GR weeds in the United States also apply to sugar beet growers. Changes in weed management strategies will be required to keep this technology. Sugar beet is arguably one of the most suitable crops for GR technology because: (1) none of the herbicides registered for use in this crop was very effective without risking crop injury; (2) sugar beet cannot be grown in the same field year after year owing to disease concerns and thus requires a 3-4 year rotation; (3) pollen-mediated gene flow is negligible from the sugar beet crop because it is a biennial and harvested before it flowers; (4) the processing of harvested roots to extract the sucrose rapidly degrades the DNA in the extracted raw juice and subsequent refining so that no DNA is present in the finished sugar; (5) studies have shown that processed GR beet sugar is identical to non-GR beet sugar, as well as cane sugar. © 2016 Society of Chemical Industry.

  2. Multi-criteria indexes to evaluate the effects of repeated organic amendment applications on soil quality

    Science.gov (United States)

    Obriot, Fiona; Stauffer, Marie; Goubard, Yolaine; Vieuble-Gonod, Laure; Revallier, Agathe; Houot, Sabine

    2015-04-01

    Objectives The soil application of organic waste products (OWP) favours the recycling of nutrients, the crop production, the increase of soil biological activity and biodiversity. It may also lead to soil contamination. All these effects occurred simultaneously and must be considered in the evaluation of the practice. This study aims at deciphering the long-term impact of repeated applications and the short-term effect of an additional application on soil quality using 5 different Soil Quality Indices (SQI)[a]: fertility, microbial activity, biodiversity, physical properties and productivity and one pollution index by heavy metals. Methodology A long term field experiment was used (QualiAgro, Ile de France) where repeated applications of 4 amendments (a municipal solid waste compost, MSW; a biowaste compost, BIO; a co-compost of sewage sludge and green waste, GWS and a farmyard manure, FYM) have differentiated soil characteristics and crop production compared to a control treatments without organic residue and receiving mineral fertilizer or not (CONT+N and CONT). The OWP are applied every 2 years, in September, at doses equivalent to 4 t C/ha (4 replicates) on a maize-wheat succession. We used 2 sampling dates: 3 weeks before application (cumulative residual effect of 7 applications) and 3 weeks just after the 8th application (short-term additional effect of a recent application), in 2011. More than 30 different variables were used: chemical (pH, Polsen…), physical (bulk density, plasticity…) and biological (microbial biomass, enzymatic activity…) soil indicators. All of these were classified in 6 classes: fertility, microbial activity, biodiversity, physical properties, productivity and pollution. Five SQI and one pollution index by heavy metals were estimated using a weighted additive index calculation method described by Velasquez et al. (2007)[a]. Only parameters with statistically significant differences (pamendments increased soil fertility and

  3. Isolation Improvement of a Microstrip Patch Array Antenna for WCDMA Indoor Repeater Applications

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    Hongmin Lee

    2012-01-01

    Full Text Available This paper presents the isolation improvement techniques of a microstrip patch array antenna for the indoor wideband code division multiple access (WCDMA repeater applications. One approach is to construct the single-feed switchable feed network structure with an MS/NRI coupled-line coupler in order to reduce the mutual coupling level between antennas. Another approach is to insert the soft surface unit cells near the edges of the microstrip patch elements in order to reduce backward radiation waves. In order to further improve the isolation level, the server antenna and donor antenna are installedinorthogonal direction. The fabricated antenna exhibits a gain over 7 dBi and higher isolation level between server and donor antennas below −70 dB at WCDMA band.

  4. Dual-Band On-Body Repeater Antenna for In-on-On WBAN Applications

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    Jinpil Tak

    2013-01-01

    Full Text Available A dual-band on-body repeater antenna for in-on-on wireless body area network applications is proposed. The proposed antenna has a maximum radiation normal to the human-body surface for communication with implanted devices in the 5.8 GHz industrial, scientific, and medical (ISM band. In addition, to transmit the biological information received from the implanted devices to other on-body devices, the proposed antenna was designed to have a monopole-like radiation pattern along the surface of the human body for communication in the 2.45 GHz ISM band. The antenna was fabricated, and its performance was measured by attaching it to a human-equivalent semisolid phantom. In addition, the human-body effect was studied to ensure antenna performance under an actual situation.

  5. Persistência do herbicida imazaquin associado ao glyphosate ou paraquat em plantio direto Persistence of imazaquin associated to glyphosate or paraquat under no-tillage

    Directory of Open Access Journals (Sweden)

    R.A Vidal

    2010-12-01

    720 g ha-1 were applied on the main plots and the residual herbicide imazaquin (300 g ha-1 on the subplots,sequentially or in association with the non-selective herbicides, plus a control, where only a non-selective herbicide was applied. The persistence of imazaquin is longer in the presence of glyphosate when compared to paraquat. No difference was found between simultaneous and sequential application of the non-selective and residual herbicides.

  6. Efficacy of repeated intrathecal triamcinolone acetonide application in progressive multiple sclerosis patients with spinal symptoms

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    Przuntek Horst

    2004-11-01

    Full Text Available Abstract Background There are controversial results on the efficacy of the abandoned, intrathecal predominant methylprednisolone application in multiple sclerosis (MS in contrast to the proven effectiveness in intractable postherpetic neuralgia. Methods We performed an analysis of the efficacy of the application of 40 mg of the sustained release steroid triamcinolone acetonide (TCA. We intrathecally injected in sterile saline dissolved TCA six times within three weeks on a regular basis every third day in 161 hospitalized primary and predominant secondary progressive MS patients with spinal symptoms. The MS patients did not experience an acute onset of exacerbation or recent distinct increased progression of symptoms. We simultaneously scored the MS patients with the EDSS and the Barthel index, estimated the walking distance and measured somatosensory evoked potentials. Additionally the MS patients received a standardized rehabilitation treatment. Results EDSS score and Barthel index improved, walking distance increased, latencies of somatosensory evoked potentials of the median and tibial nerves shortened in all MS patients with serial evaluation (p Conclusions Repeated intrathecal TCA application improves spinal symptoms, walking distance and SSEP latencies in progressive MS patients in this uncontrolled study. Future trials should evaluate the long-term benefit of this invasive treatment.

  7. Repeating Knowledge Application Practice to Improve Student Performance in a Large, Introductory Science Course

    Science.gov (United States)

    Fujinuma, Ryosuke; Wendling, Laura A.

    2015-11-01

    There is a tendency for lecture-based instruction in large introductory science courses to strongly focus on the delivery of discipline-specific technical terminology and fundamental concepts, sometimes to the detriment of opportunities for application of learned knowledge in evidence-based critical-thinking activities. We sought to improve student performance on evidence-based critical-thinking tasks through the implementation of peer learning and problem-based learning tutorial activities. Small-group discussions and associated learning activities were used to facilitate deeper learning through the application of new knowledge. Student performance was assessed using critical-thinking essay assignments and a final course exam, and student satisfaction with tutorial activities was monitored using online surveys. Overall, students expressed satisfaction with the small-group-discussion-based tutorial activities (mean score 7.5/10). Improved critical thinking was evidenced by improved student performance on essay assignments during the semester, as well as a 25% increase in mean student scores on the final course exam compared to previous years. These results demonstrate that repeated knowledge application practice can improve student learning in large introductory-level science courses.

  8. Sensitivity to glyphosate and dynamics of shikimate accumulation in three weed species following glyphosate application%三种杂草对草甘膦的敏感性及处理后植株体内莽草酸积累量差异

    Institute of Scientific and Technical Information of China (English)

    陈景超; 张朝贤; 黄红娟; 魏守辉; 张猛; 郭峰

    2011-01-01

    为明确不同杂草对草甘膦的敏感性,以稗Echinochloa crusgalli、马唐Digitaria sanguinalis、藜Chenopodium album为供试材料,采用生物测定法和吸光光度法分别测定了草甘膦对3种杂草的抑制中浓度( GR50),以及不同剂量处理后杂草体内莽草酸积累量的变化.经410 g/hm2(有效成分)的草甘膦处理后,稗体内莽草酸积累量呈上升-下降-上升趋势,而马唐和藜则表现为缓慢上升,根据此剂量处理下莽草酸积累趋势得出,3种杂草对草甘膦的敏感性由高到低依次为稗、藜和马唐,与生测法的结果一致.经820 ~3 280 g/hm2(有效成分)的草甘膦处理后,3种杂草体内莽草酸积累量从第2d开始急剧升高,增长速率随着草甘膦处理剂量的增加而加大;处理后稗、马唐和藜体内莽草酸积累量最高值差异显著,分别为1 137.9、4 989.7和2 084.2 μg/g,为各自对照水平的16.7、23.7和82.9倍.该研究结果可为系统检测杂草对草甘膦的敏感性提供依据.%The GR50 value and shikimate accumulation in three problematic weed species were determined by whole plant bioassay and spectrophotometric assay, respectively, after treated by glyphosate. After treated by glyphosate at 410 g (a. I. )/ha, shikimate accumulation in Echinochloa crusgalli was first increased, then declined, increased slightly finally. However, it kept increasing in Chenopodium album and Digitaria sanguinalis. Based on the accumulation of shikimate by glyphosate treated within this dosage, the order of sensitivity to glyphosate from high to low was E. Crusgalli, C. Album and D. Sanguinalis, which was similar to the result of whole plant bioassay. Shikimate accumulation was increased rapidly in all three weeds after treated 2 days by glyphosate within the dose range of 820 to 3 280 g(a. I. )/ha, and the accumulation rate showed positive relationship to the treatment dosage. The highest shikimate accumulation in E. Crusgalli,D. Sanguinalis and C

  9. Glyphosate induces cardiovascular toxicity in Danio rerio.

    Science.gov (United States)

    Roy, Nicole M; Ochs, Jeremy; Zambrzycka, Ewelina; Anderson, Ariann

    2016-09-01

    Glyphosate is a broad spectrum herbicide used aggressively in agricultural practices as well as home garden care. Although labeled "safe" by the chemical industry, doses tested by industry do not mimic chronic exposures to sublethal doses that organisms in the environment are exposed to over long periods of time. Given the widespread uses of and exposure to glyphosate, studies on developmental toxicity are needed. Here we utilize the zebrafish vertebrate model system to study early effects of glyphosate on the developing heart. Treatment by embryo soaking with 50μg/ml glyphosate starting at gastrulation results in structural abnormalities in the atrium and ventricle, irregular heart looping, situs inversus as well as decreased heartbeats by 48h as determined by live imaging and immunohistochemistry. Vasculature in the body was also affected as determined using fli-1 transgenic embryos. To determine if the effects noted at 48h post fertilization are due to early stage alterations in myocardial precursors, we also investigate cardiomyocyte development with a Mef2 antibody and by mef2ca in situ hybridization and find alterations in the Mef2/mef2ca staining patterns during early cardiac patterning stages. We conclude that glyphosate is developmentally toxic to the zebrafish heart.

  10. Glyphosate-Resistant Goosegrass from Mississippi

    Directory of Open Access Journals (Sweden)

    Vijay K. Nandula

    2013-05-01

    Full Text Available A suspected glyphosate-resistant goosegrass [Eleusine indica (L. Gaertn.] population, found in Washington County, Mississippi, was studied to determine the level of resistance and whether the resistance was due to a point mutation, as was previously identified in a Malaysian population. Whole plant dose response assays indicated a two- to four-fold increase in resistance to glyphosate. Leaf disc bioassays based on a glyphosate-dependent increase in shikimate levels indicated a five- to eight-fold increase in resistance. Sequence comparisons of messenger RNA for epsps, the gene encoding the enzyme 5-enolpyruvylshikimate-3-phosphate synthase, from resistant and sensitive goosegrass, revealed a cytosine to thymine nucleotide change at position 319 in the resistant accessions. This single nucleotide polymorphism causes a proline to serine amino acid substitution at position 106 in 5-enolpyruvylshikimate-3-phosphate synthase. A real-time polymerase chain reaction assay using DNA probes specific for the nucleotide change at position 319 was developed to detect this polymorphism. Goosegrass from 42 locations were screened, and the results indicated that glyphosate-resistant goosegrass remained localized to where it was discovered. Pendimethalin, s-metolachlor, clethodim, paraquat and fluazifop controlled resistant goosegrass 93% to 100%, indicating that several control options for glyphosate-resistant goosegrass are available.

  11. EFFECTIVENESS OF GLYPHOSATE AND 2.4 D AMIN HERBICIDES TO CONTROL WEEDS UNDER Shorea selanica Bl. PLANTATION IN CARITA TRIAL GARDEN, BANTEN

    Directory of Open Access Journals (Sweden)

    Ari Wibowo

    2007-03-01

    Full Text Available A trial was carried out in Carita, West Java, to identify the effectiveness of Glyphosate and 2.4 D Amin Herbicide to control weeds under Shorea selanica Bl. plantation. The trial was conducted through the application of Glyphosate and 2.4 D Amin Herbicide with dosages of 5, 6, 7, 8 and 9 liter per ha and compared with Glyphosate herbicide 5 liter per ha, manual treatment, and control (no treatment. The result showed that Glyphosate and 2.4 D Amin Herbicide could be used to control weeds in order to maintaining S. selanica Bl. plantation. Minimum dosage of 6 liter/ha was effective to control weeds such as Chromolaena odorata DC, Mikania micrantha Will, Lantana camara L, Imperata cylindrica Beauv., Melastoma malabathricum L, and Boreria latifolia Bl. Furthermore, there was no symptom of poison on S. selanica Bl. plantation after herbicide application with all dosages applied.

  12. Possible glyphosate tolerance mechanism in pitted morningglory (Ipomoea lacunosa L.).

    Science.gov (United States)

    Ribeiro, Daniela N; Nandula, Vijay K; Dayan, Franck E; Rimando, Agnes M; Duke, Stephen O; Reddy, Krishna N; Shaw, David R

    2015-02-18

    Natural tolerance of Ipomoea lacunosa to glyphosate has made it problematic in the southeastern U.S. since the adoption of glyphosate-resistant crops. Experiments were conducted to determine (i) the variability in tolerance to glyphosate among accessions, (ii) if there is any correlation between metabolism of glyphosate to aminomethylphosponic acid (AMPA) or sarcosine and the level of tolerance, and (iii) the involvement of differential translocation in tolerance to glyphosate. Fourteen I. lacunosa accessions had GR50 values ranging from 58 to 151 grams of acid equivalent per hectare (ae/ha) glyphosate, a 2.6-fold variability in tolerance to glyphosate. There was no evidence of the most tolerant (MT) accession metabolizing glyphosate to AMPA more rapidly than the least tolerant (LT) accession. Metabolism to sarcosine was not found. (14)C-glyphosate absorption was similar in the two accessions. LT accession translocated more (14)C-glyphosate than MT accession at 24 and 48 h after treatment. Differential translocation partly explains glyphosate tolerance in MT accession.

  13. Oral bioavailability of glyphosate: studies using two intestinal cell lines.

    Science.gov (United States)

    Vasiluk, Luba; Pinto, Linda J; Moore, Margo M

    2005-01-01

    Glyphosate is a commonly used nonselective herbicide that inhibits plant growth through interference with the production of essential aromatic amino acids. In vivo studies in mammals with radiolabeled glyphosate have shown that 34% of radioactivity was associated with intestinal tissue 2 h after oral administration. The aim of our research was to investigate the transport, binding, and toxicity of glyphosate to the cultured human intestinal epithelial cell line, Caco-2, and the rat small intestinal crypt-derived cell line, ileum epithelial cells-18 (IEC-18). An in vitro analysis of the transport kinetics of [14C]-glyphosate showed that 4 h after exposure, approximately 8% of radiolabeled glyphosate moved through the Caco-2 monolayer in a dose-dependent manner. Binding of glyphosate to cells was saturable and approximately 4 x 10(11) binding sites/cell were estimated from bound [14C]. Exposure of Caco-2 cells to > or =10 mg/ml glyphosate reduced transmembrane electrical resistance (TEER) by 82 to 96% and increased permeability to [3H]-mannitol, indicating that paracellular permeability increased in glyphosate-treated cells. At 10-mg/ml glyphosate, both IEC-18 and Caco-2 cells showed disruption in the actin cytoskeleton. In Caco-2 cells, significant lactate dehydrogenase leakage was observed when cells were exposed to 15 mg/ml of glyphosate. These data indicate that at doses >10 mg/ml, glyphosate significantly disrupts the barrier properties of cultured intestinal cells.

  14. Characterization of glyphosate resistance in Amaranthus tuberculatus populations.

    Science.gov (United States)

    Lorentz, Lothar; Gaines, Todd A; Nissen, Scott J; Westra, Philip; Strek, Harry J; Dehne, Heinz W; Ruiz-Santaella, Juan Pedro; Beffa, Roland

    2014-08-13

    The evolution of glyphosate-resistant weeds has recently increased dramatically. Six suspected glyphosate-resistant Amaranthus tuberculatus populations were studied to confirm resistance and determine the resistance mechanism. Resistance was confirmed in greenhouse for all six populations with glyphosate resistance factors (R/S) between 5.2 and 7.5. No difference in glyphosate absorption or translocation was observed between resistant and susceptible individuals. No mutation at amino acid positions G101, T102, or P106 was detected in the EPSPS gene coding sequence, the target enzyme of glyphosate. Analysis of EPSPS gene copy number revealed that all glyphosate-resistant populations possessed increased EPSPS gene copy number, and this correlated with increased expression at both RNA and protein levels. EPSPS Vmax and Kcat values were more than doubled in resistant plants, indicating higher levels of catalytically active expressed EPSPS protein. EPSPS gene amplification is the main mechanism contributing to glyphosate resistance in the A. tuberculatus populations analyzed.

  15. Effect of glyphosate on reproductive organs in male rat.

    Science.gov (United States)

    Dai, Pengyuan; Hu, Ping; Tang, Juan; Li, Yansen; Li, Chunmei

    2016-06-01

    Glyphosate as an active ingredient of Roundup(®) which is thought to be one of the most popular herbicide was used worldwide. Many studies have focused on reproductive toxicity on glyphosate-based herbicide, but few evidence exists to imply the male reproductive toxicity of glyphosate alone in vivo. In this study SD rats were Lavaged with glyphosate at doses of 5, 50, 500mg/kg to detect the toxicity of glyphosate on rat testis. Glyphosate significantly decreased the average daily feed intake at dose of 50mg/kg, and the weight of seminal vesicle gland, coagulating gland as well as the total sperm count at dose of 500mg/kg. Immunohistochemistry of androgen receptor (AR) has no difference among all groups. As to testosterone, estradiol, progesterone and oxidative stress parameters, the level of them has no differences amidst all doses. Taken together, we conclude that glyphosate alone has low toxicity on male rats reproductive system.

  16. Cadmium adsorption in montmorillonite as affected by glyphosate

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-jun; ZHOU Dong-mei; LUO Xiao-san; SUN Rui-juan; CHEN Huai-man

    2004-01-01

    Behaviors of soil heavy metals are often affected by coexisting herbicides due to their physical and chemical interaction. Effect of glyphosate, an herbicide containing -PO32- and -COOH groups, on cadmium adsorption in montmorillonite was studied in detail. The results showed that cadmium adsorption quantity in montmorillonite increased with increasing soil solution pH and cadmium concentration as usual, but decreased with glyphosate, which is due to the formation of a low affinity complex of Cd and glyphosate and decreasing solution pH induced by glyphosate addition. When the equilibrium solution pH was below 6.7, glyphosate has little effect on cadmium adsorption, but when the equilibrium solution pH was above 6.7, glyphosate significantly decreased cadmium adsorption quantity in montmorillonite. In addition, the adding order of Cd and glyphosate also influenced Cd adsorption quantity in montmorillonite.

  17. Identificação de biótipos de azevém (Lolium multiflorum resistentes ao herbicida glyphosate em pomares de maçã Identification of glyphosate-resistant ryegrass (Lolium multiflorum biotypes in apple orchards

    Directory of Open Access Journals (Sweden)

    L. Vargas

    2004-12-01

    geral, evidenciam que o biótipo sensível é facilmente controlado com o herbicida glyphosate e pelos demais herbicidas pós-emergentes avaliados, independentemente do estádio vegetativo. Demonstram, ainda, que o biótipo resistente apresenta-se, igualmente ao biótipo sensível, altamente suscetível aos herbicidas com mecanismo de ação distinto daquele do glyphosate. No entanto, o biótipo resistente apresenta baixa resposta ao herbicida glyphosate, mesmo se este for empregado em altas doses, evidenciando ter adquirido resistência a esse produto.Glyphosate is a wide spectrum herbicide used for over 15 years in apple orchards in Vacaria-RS for weed control in rows of trees. Usually, 3 to 4 applications per year are made at a rate of 720 to 1080 g a.e. glyphosate ha-1 (2 to 3 L ha-1 of commercial product. Ryegrass (Lolium multiflorum is a common weed in orchards and traditionally sensitive to glyphosate. However, in the last years, some ryegrass plants have not been found to show significant toxicity symptoms after treatment with glyphosate, suggesting that they acquired resistance to this product. To evaluate the response of a ryegrass plant population to glyphosate, one field and two greenhouse experiments were carried out. The field experiment treatments had increasing rates of glyphosate (0; 360; 720; 1,440; 2,880; 5,760 and 11,520 g a.e. ha-1, in addition to the herbicides paraquat, glufosinate-ammonium, haloxyfop and diclofop-methyl as standards, sprayed at two different vegetative growth stages of ryegrass. The greenhouse experiments had increasing rates of glyphosate (0; 360; 720; 1,440; 2,880 and 5,760 g a.e. ha-1 plus the above listed check herbicides sprayed on biotypes considered resistant and on plants of one susceptible biotype. In the second greenhouse experiment, glyphosate rates (720; 1,440; 2,880; 720 + 720 and 720 + 1,440 g a.e. ha-1 were sprayed in single and sequential applications, in addition to the herbicides paraquat, glufosinate

  18. 草甘膦对土壤微生物的影响%Effects of glyphosate on soil microorganisms

    Institute of Scientific and Technical Information of China (English)

    陶波; 蒋凌雪; 沈晓峰; 栾凤侠; 邱丽娟

    2011-01-01

    Black soil in northeast region of China was used to investigate the effects of glyphosate on soil respiration, soil cultural bacteria, Rhizobium japonicum and Fusarium oxysporum, to provide a theoretical basis for the evaluation of environmental safety of glyphosate. The results showed that increasing glyphosate concentration increased the inhibition on soil respiration. When glyphosate concentration in soil were ling · kg-1 , 10mg · kg-1 and 100 mg · kg-1 , the risk index were 1.20, 0. 322 and 0.076, which were less than the standard index of 20.Glyphosate influenced quantities of soil fungi and actinomycetes. High glyphosate concentration increased the inhibition to population of soil cultural bacteria. With the extended application of glyphosate, soil fungus, bacteria and actinomycetes populations had been restored. Actinomycetes were more sensitive to glyphosate than fungus and bacteria, and soil bacteria had a strong tolerance or degrading ability to glyphosate. Glyphosate impacted on inhibiting Rhizobium japonicum and Fusarium oxysporum, and the inhibition of Rhizobium japonicum was in direct proportion with the concentration of glyphosate. Low glyphosate concentration promoted Fusarium oxysporum populations,while high concentration inhibited them. The extended application time of glyphosate decreased the inhibition of glyphosate on Rhizobium japonicum and Fusarium oxysporum.%以东北地区黑土为材料,探讨草甘膦对土壤呼吸、土壤可培养菌种群数量、大豆固氮根瘤菌和大豆根腐镰刀菌数量的影响.研究结果表明,随着草甘膦浓度的加大,土壤呼吸的抑制作用增强,土壤中草甘膦含量为1mg·kg-1、10mg·kg-1、100mg·kg-1时,危害系数分别为1.20、0.322、0.076,远小于无危害标准系数20,确定草甘膦对土壤微生物低毒或无实际危害.不同浓度的草甘膦对土壤真菌、放线菌种群数量具有一定影响.土壤可培养菌种群数量随草甘膦浓度的升高抑制作

  19. Glyphosate-resistant crops: adoption, use and future considerations.

    Science.gov (United States)

    Dill, Gerald M; Cajacob, Claire A; Padgette, Stephen R

    2008-04-01

    Glyphosate-resistant crops (GRCs) were first introduced in the United States in soybeans in 1996. Adoption has been very rapid in soybeans and cotton since introduction and has grown significantly in maize in recent years. GRCs have grown to over 74 million hectares in five crop species in 13 countries. The intent of this paper is to update the hectares planted and the use patterns of GRC globally, and to discuss briefly future applications and uses of the technology. The largest land areas of GRCs are occupied by soybean (54.2 million ha), maize (13.2 million ha), cotton (5.1 million ha), canola (2.3 million ha) and alfalfa (0.1 million ha). Currently, the USA, Argentina, Brazil and Canada have the largest plantings of GRCs. Herbicide use patterns would indicate that over 50% of glyphosate-resistant (GR) maize hectares and 70% of GR cotton hectares receive alternative mode-of-action treatments, while approximately 25% of GR soybeans receive such a treatment in the USA. Alternative herbicide use is likely driven by both agronomic need and herbicide resistance limitations in certain GR crops such as current GR cotton. Tillage practices in the USA indicate that > 65% of GR maize hectares, 70% of GR cotton hectares and 50% of GR soybean hectares received some tillage in the production system. Tillage was likely used for multiple purposes ranging from seed-bed preparation to weed management. GRCs represent one of the more rapidly adopted weed management technologies in recent history. Current use patterns would indicate that GRCs will likely continue to be a popular weed management choice that may also include the use of other herbicides to complement glyphosate. Stacking with other biotechnology traits will also give farmers the benefits and convenience of multiple pest control and quality trait technologies within a single seed. Copyright (c) 2007 Society of Chemical Industry.

  20. Aminomethylphosphonic acid accumulation in plant species treated with glyphosate.

    Science.gov (United States)

    Reddy, Krishna N; Rimando, Agnes M; Duke, Stephen O; Nandula, Vijay K

    2008-03-26

    Aminomethylphosphonic acid (AMPA) is the most frequently detected metabolite of glyphosate in plants. The objective of this study was to determine if there is any correlation of metabolism of glyphosate to AMPA in different plant species and their natural level of resistance to glyphosate. Greenhouse studies were conducted to determine the glyphosate I 50 values (rate required to cause a 50% reduction in plant growth) and to quantify AMPA and shikimate concentrations in selected leguminous and nonleguminous species treated with glyphosate at respective I 50 rates. Coffee senna [ Cassia occidentalis (L.) Link] was the most sensitive ( I 50 = 75 g/ha) and hemp sesbania [ Sesbania herbacea (P.Mill.) McVaugh] was the most resistant ( I 50 = 456 g/ha) to glyphosate. Hemp sesbania was 6-fold and Illinois bundleflower [ Desmanthus illinoensis (Michx.) MacM. ex B.L.Robins. & Fern.] was 4-fold more resistant to glyphosate than coffee senna. Glyphosate was present in all plant species, and its concentration ranged from 0.308 to 38.7 microg/g of tissue. AMPA was present in all leguminous species studied except hemp sesbania. AMPA concentration ranged from 0.119 to 4.77 microg/g of tissue. Shikimate was present in all plant species treated with glyphosate, and levels ranged from 0.053 to 16.5 mg/g of tissue. Non-glyphosate-resistant (non-GR) soybean accumulated much higher shikimate than glyphosate-resistant (GR) soybean. Although some leguminous species were found to be more resistant to glyphosate than others, and there was considerable variation between species in the glyphosate to AMPA levels found, metabolism of glyphosate to AMPA did not appear to be a common factor in explaining natural resistance levels.

  1. Schemes of Repeater Optimizing Distribution based on the MLC Application and CBLRD Simulation

    Directory of Open Access Journals (Sweden)

    Qian Qiuye

    2013-07-01

    Full Text Available The widely use of repeaters raises concern about their coordination among the public. Since repeaters may suffer interaction and limitation bearing capacity, designing a reasonable repeaters coordination method is of great significance. This study address the problem if repeater coordination in a circular flat area with minimal number of repeaters with seamless coverage theory, system simulation method. With 1,000 users, this study model the coverage, getting the minimal number of repeaters of different coverage radius based on extensive used regular hexagon coverage theory. A numerical example was given in this case. When the number of users increases to 10,000, this study simulate to get the signal density across the area according to the consideration of repeaters and the different distribution of users, which are divided into uniform distribution, linear distribution, normal distribution and lognormal distribution. Then, Multi-Layer Coverage (MLC and Coverage by Link Rate Density (CBLRD are created as the distribution scheme on the area where repeat service demand is large. Moreover, for solution on the distribution of the repeaters with barriers, distribution schemes are given considering the transmission of VHF spectrums and the distribution of users around the barrier. Additionally, Spring Comfortable Degree (SCD is used for evaluation of the results and the developing tends are given to improve the model. Due to the reasonable assumption, the solution of repeater distribution is of pivotal reference value based on the reasonable results.

  2. Efeito de formulações na absorção e translocação do glyphosate em soja transgênica Effect of formulations on the absorption and translocation of glyphosate in transgenic soybean

    Directory of Open Access Journals (Sweden)

    J.B. Santos

    2007-01-01

    , and Zapp Qi®, formulated from potassic salt , using a precision micro syringe. Plant samples were collected after herbicide application (4, 16, 40 and 64 hours and then divided into leaf (trifolium, aerial part, roots and root nodes for radiation reading. 14C-glyphosate that was not absorbed was recovered and counted by washing the leaf with methanol. Penetration and translocation of 14C-glyphosate to the different parts evaluated was found to vary. However, the highest absorption was verified at intervals after 16 hours of application. The highest herbicide percentage in the aerial part of the soybean plants was found when Zapp (potassic salt was applied on the aerial part and when isopropylamin salt was applied on the roots; 14C-glyphosate was found in the plant root nodules in all treatments, with the highest percentage being observed with R. Transorb®, 40 hours after application (0.13% of the total measured or 0.4%, considering only the plant total. Results highlight the hypothesis that glyphosate could harm symbiosis between rhizobium and soybean, since the former also shows in its metabolism EPSPS, which is susceptible to this herbicide.

  3. Adição simultânea de sulfato de amônio e ureia à calda de pulverização do herbicida glyphosate Simultaneous addition of ammonium sulfate and urea to glyphosate spray solution

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    S.J.P. Carvalho

    2010-01-01

    Full Text Available Dois experimentos foram desenvolvidos em casa de vegetação, com o objetivo de avaliar a eficácia do herbicida glyphosate sobre plantas de Digitaria insularis quando soluções de ureia (U; 5 g L-1, sulfato de amônio (SA; 15 g L-1 ou U+SA (2,5 + 7,5 g L-1 foram utilizadas como veículo de pulverização. Aos 28 dias após aplicação, de acordo com as curvas de dose-resposta (primeiro experimento, foram necessários 409 g ha-1 de glyphosate para atingir 50% de controle da planta daninha (C50 quando água sem adjuvantes foi usada como veículo de pulverização. Para obtenção dos mesmos 50% de controle, as doses de glyphosate foram reduzidas para 373, 208 e 189 g ha-1; quando o herbicida foi pulverizado utilizando solução de U, SA ou U+SA, respectivamente. A redução na dose oriunda da combinação de glyphosate e U+SA também foi observada para controles de 80% (C80. No segundo experimento, a adição de U+SA à calda elevou o controle obtido com a menor dose de glyphosate (360 g ha-1, igualando-o à aplicação da maior dose (720 g ha-1 sem adjuvantes. Esses resultados evidenciam efeito complementar de U e SA em elevar a eficácia do glyphosate para controle de D. insularis.Two trials were carried out under greenhouse conditions to evaluate the efficacy of glyphosate on Digitaria insularis plants when urea (U; 5 g L-1; ammonium sulfate (AMS; 15 g L-1 or U+AMS (2.5 + 7.5 g L-1 were used as spray solutions. At 28 days after application, according to dose-response curves (first trial, 409 g ha-1 of glyphosate application were necessary to obtain 50% of weed control (C50 when water without adjuvants was used as spray solution. To reach the same 50% of weed control, glyphosate rates were reduced to 373, 208 and 189 g ha-1, when the herbicide was sprayed using a solution of U, AMS or U+AMS, respectively. Reduction in the dose of glyphosate combined with U+AMS was also observed for controls of 80% (C80. In the second trial, the addition of U

  4. IMPACT OF GLYPHOSATE ON MICROBIAL ATTRIBUTES OF SOI L PLANTED WITH TWO SPECIES OF PASSION FRUIT

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    ERIKA VALENTE DE MEDEIROS

    2014-01-01

    Full Text Available Glyphosate is one of best known agrochemicals and i s used to prevent the spread of weeds. However, little is known about the impact of this c hemical on non-target organisms such as the soil mi crobial community. Therefore, the objective of this study w as to evaluate the effect of glyphosate on the micr oorgan- ism population and the microbial attributes of soil s cultivated with yellow and sweet passion fruits. The experi- mental design used was complete randomized blocks i n a 3 x 2 factorial scheme with the times of soil s ample collection (0, 5 and 47 days after herbicide applic ation- DAH and the two species of passion fruit ye llow ( Passiflorae dulis f. flavicarpa O. Deg. and sweet ( Passiflora alata Dryand as the factors,with three replica- tions. No impact of the glyphosate herbicide was fo undon the bacterial communities of soil. However, a mild and transitory impact was observedon the fungal pop ulations, encouraging these populationsat 47 DHA. G ly- phosate changed the carbon microbial biomass and so il microbial attributes, except for total organic c arbon. Multivariate, principal component analysis revealed that the total bacteria, endospore-forming bacteri a, total fungi, carbon microbial biomass and metabolic quoti ent attributes of soil are the most sensitive facto rs for pre- dicting the impact of glyphosate on biological indi cators of soil planted with two species of passion fruit yellow ( P. edulis f. Flavicarpa and sweet ( P. alata .

  5. EPSPS variability, gene expression, and enzymatic activity in glyphosate-resistant biotypes of Digitaria insularis.

    Science.gov (United States)

    Galeano, E; Barroso, A A M; Vasconcelos, T S; López-Rubio, A; Albrecht, A J P; Victoria Filho, R; Carrer, H

    2016-08-12

    Weed resistance to herbicides is a natural phenomenon that exerts selection on individuals in a population. In Brazil, glyphosate resistance was recently detected in Digitaria insularis. The objective of this study was to elucidate mechanisms of weed resistance in this plant, including genetic variability, allelism, amino acid substitutions, gene expression, and enzymatic activity levels. Most of these have not previously been studied in this species. D. insularis DNA sequences were used to analyze genetic variability. cDNA from resistant and susceptible plants was used to identify mutations, alleles, and 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) expression, using real-time quantitative reverse transcription-polymerase chain reaction. In addition, EPSPS activity was measured. We found a decrease in genetic variability between populations related to glyphosate application. Substitutions from proline to threonine and tyrosine to cysteine led to a decrease in EPSPS affinity for the glyphosate. In addition, the EPSPS enzymatic activity was slightly higher in resistant plants, whereas EPSPS gene expression was almost identical in both biotypes, suggesting feedback regulation at different levels. To conclude, our results suggest new molecular mechanisms used by D. insularis to increase glyphosate resistance.

  6. Leaf anatomy and morphometry in three eucalypt clones treated with glyphosate

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    LD. Tuffi Santos

    Full Text Available This work aimed to evaluate the effects of simulated drift of glyphosate on the morphoanatomy of three eucalypt clones and to correlate the intoxication symptoms on a microscopic scale with those observed in this visual analysis. The effects of glyphosate drift were proportional to the five doses tested, with Eucalyptus urophylla being more tolerant to the herbicide than E. grandis and urograndis hybrid. The symptoms of intoxication which were similar for the different clones at 7 and 15 days after application were characterized by leaf wilting, chlorosis and curling and, at the highest rates, by necrosis, leaf senescence and death. Anatomically glyphosate doses higher than 86.4 g.ha-1 caused cellular plasmolysis, hypertrophy and hyperplasia, formation of the cicatrization tissue and dead cells on the adaxial epidermis. The spongy parenchyma had a decrease, and the palisade parenchyma and leaf blade thickness had an increase. The increased thickness in leaf blade and palisade parenchyma may be related to the plant response to glyphosate action, as a form of recovering the photosynthetically active area reduced by necroses and leaf senescence caused by the herbicide.

  7. Glyphosate transport through weathered granite soils under irrigated and non-irrigated conditions--Barcelona, Spain.

    Science.gov (United States)

    Candela, Lucila; Caballero, Juan; Ronen, Daniel

    2010-05-15

    The transport of Glyphosate ([N-phosphonomethyl] glycine), AMPA (aminomethylphosphonic acid, CH(6)NO(3)P), and Bromide (Br(-)) has been studied, in the Mediterranean Maresme area of Spain, north of Barcelona, where groundwater is located at a depth of 5.5m. The unsaturated zone of weathered - granite soils was characterized in adjacent irrigated and non-irrigated experimental plots where 11 and 10 boreholes were drilled, respectively. At the non irrigated plot, the first half of the period was affected by a persistent and intense rainfall. After 69 days of application residues of Glyphosate up to 73.6 microgg(-1) were detected till a depth of 0.5m under irrigated conditions, AMPA, analyzed only in the irrigated plot was detected till a depth of 0.5m. According to the retardation coefficient of Glyphosate as compared to that of Br(-) for the topsoil and subsoil (80 and 83, respectively) and the maximum observed migration depth of Br(-) (2.9 m) Glyphosate and AMPA should have been detected till a depth of 0.05 m only. Such migration could be related to the low content of organic matter and clays in the soils; recharge generated by irrigation and heavy rain, and possible preferential solute transport and/or colloidal mediated transport. Copyright 2010 Elsevier B.V. All rights reserved.

  8. Glyphosate in Runoff Waters and in the Root-Zone: A Review

    OpenAIRE

    Lyndsay E. Saunders; Reza Pezeshki

    2015-01-01

    Glyphosate is the most commonly-used herbicide in the world. The present review summarizes the discovery, prevalence, chemical and physical properties, mode of action and effects in plants, glyphosate resistance and the environmental fate of glyphosate. Numerous studies are reviewed that demonstrate that glyphosate may run off of fields where it is applied, while other studies provide evidence that plant roots can take up glyphosate. Non-target vegetation may be exposed to glyphosate in the r...

  9. Deriva simulada de formulações comerciais de glyphosate sobre maracujazeiro amarelo Drift simulation of glyphosate commercial formulations on yellow passion fruit growth

    Directory of Open Access Journals (Sweden)

    A. Wagner Júnior

    2008-01-01

    experiment was arranged in a completely randomized block design, with five replications, in a factorial 3 x 4 + 1, consisting of three glyphosate formulations and five doses, (one being the control without herbicide. Each plot was constituted by one plant. The applied doses of glyphosate were 43.2; 86.4; 172.8 and 345.6 g ha-1, using the commercial formulations: Roundup Transorb®, Roundup Original® and Zapp QI®. After 28 days of application, aerial part, root and total length (cm, stem diameter (mm, number of leaves and primary ramifications, aerial part and root dry mass,(g and the foliar area per plant (cm² were evaluated. After 7, 14 and 28 application days, intoxication percentage of the plants was also evaluated. Regardless of the formulations used, glyphosate drift simulation caused injury to the yellow passion fruit, reducing plant growth. The herbicides Roundup Transorb® and Roundup Original® were more harmful than Zapp Qi®. The yellow passion fruit was susceptible to drift simulation; thus, glyphosate must be used carefully, so as to reach only the weeds to be controlled.

  10. Coca (Erythroxylum coca) Control is Affected by Glyphosate Formulations and Adjuvants.

    Science.gov (United States)

    Marshall, E J P; Solomon, Keith R; Carrasquilla, Gabriel

    2009-01-01

    The aerial spray program for the eradication of coca in Colombia uses Glyphos, a local formulation of glyphosate tank-mixed with an adjuvant product, Cosmo-Flux. There are some potential risks to amphibians from direct overspraying of shallow waters. In order to evaluate potential alternative mixtures, a field experiment was conducted at the Center of National Training of Police Operations in Tolima province, Colombia. Plants of coca were established with irrigation and grown to 75 cm tall. A randomized split-plot design experiment was laid out and sprayed with a range of glyphosate formulations and different adjuvants using an experimental ground sprayer. Assessments were made of plant vigor, height, and above-ground standing crop (fresh weight) 3 wk after application. Resprouting of plants was assessed at 9 wk after treatment. Unformulated glyphosate applied as the product Rodeo gave poorer control of coca than two formulated products, Roundup Biactive (from Europe) and Colombian Glyphos. In general, these products performed well without added adjuvants, giving control similar to that of the eradication mixture with Cosmo-Flux. There was some evidence that addition of the adjuvant Silwet L-77 and to a lesser extent Mixture B (from the United Kingdom) gave more rapid herbicide symptoms. There were also indications that glyphosate rates of less than 3.69 kg acid equivalents (a.e.)/ha could give control in the range of 95%. Depending on the environmental risk requirements, the experiment indicates that, should other spray mixtures be required, there are potential alternatives. These would require extensive field testing to cover different environmental conditions, different coca varieties, and particularly aerial application, prior to a recommendation. Should the glyphosate product require changing, Roundup Biactive may be considered. Should the adjuvant require changing, then on the basis of this research, Silwet L-77 and Mixture B would be good candidates for

  11. Repeated application of composted tannery sludge affects differently soil microbial biomass, enzymes activity, and ammonia-oxidizing organisms.

    Science.gov (United States)

    Araújo, Ademir Sérgio Ferreira; Lima, Luciano Moura; Santos, Vilma Maria; Schmidt, Radomir

    2016-10-01

    Repeated application of composted tannery sludge (CTS) changes the soil chemical properties and, consequently, can affect the soil microbial properties. The aim of this study was to evaluate the responses of soil microbial biomass and ammonia-oxidizing organisms to repeated application of CTS. CTS was applied repeatedly during 6 years, and, at the sixth year, the soil microbial biomass, enzymes activity, and ammonia-oxidizing organisms were determined in the soil. The treatments consisted of 0 (without CTS application), 2.5, 5, 10, and 20 t ha(-1) of CTS (dry basis). Soil pH, EC, SOC, total N, and Cr concentration increased with the increase in CTS rate. Soil microbial biomass did not change significantly with the amendment of 2.5 Mg ha(-1), while it decreased at the higher rates. Total and specific enzymes activity responded differently after CTS application. The abundance of bacteria did not change with the 2.5-Mg ha(-1) CTS treatment and decreased after this rate, while the abundance of archaea increased significantly with the 2.5-Mg ha(-1) CTS treatment. Repeated application of different CTS rates for 6 years had different effects on the soil microbial biomass and ammonia-oxidizing organisms as a response to changes in soil chemical properties.

  12. Glyphosate resistance in Ambrosia trifida: Part 1. Novel rapid cell death response to glyphosate.

    Science.gov (United States)

    Van Horn, Christopher R; Moretti, Marcelo L; Robertson, Renae R; Segobye, Kabelo; Weller, Stephen C; Young, Bryan G; Johnson, William G; Schulz, Burkhard; Green, Amanda C; Jeffery, Taylor; Lespérance, Mackenzie A; Tardif, François J; Sikkema, Peter H; Hall, J Christopher; McLean, Michael D; Lawton, Mark B; Sammons, R Douglas; Wang, Dafu; Westra, Philip; Gaines, Todd A

    2017-03-07

    Glyphosate-resistant (GR) Ambrosia trifida is now present in the midwestern United States and in southwestern Ontario, Canada. Two distinct GR phenotypes are known, including a rapid response (GR RR) phenotype, which exhibits cell death within hours after treatment, and a non-rapid response (GR NRR) phenotype. The mechanisms of resistance in both GR RR and GR NRR remain unknown. Here, we present a description of the RR phenotype and an investigation of target-site mechanisms on multiple A. trifida accessions. Glyphosate resistance was confirmed in several accessions, and whole-plant levels of resistance ranged from 2.3- to 7.5-fold compared with glyphosate-susceptible (GS) accessions. The two GR phenotypes displayed similar levels of resistance, despite having dramatically different phenotypic responses to glyphosate. Glyphosate resistance was not associated with mutations in EPSPS sequence, increased EPSPS copy number, EPSPS quantity, or EPSPS activity. These encompassing results suggest that resistance to glyphosate in these GR RR A. trifida accessions is not conferred by a target-site resistance mechanism. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  13. Interação de glyphosate com carfentrazone-ethyl Glyphosate - carfentrazone-ethyl interaction

    Directory of Open Access Journals (Sweden)

    R.C. Werlang

    2002-04-01

    Full Text Available Foi conduzido um experimento em condições controladas para determinar a interação do carfentrazone-ethyl em mistura no tanque com o herbicida glyphosate, no controle de seis espécies de plantas daninhas. Glyphosate aplicado isoladamente na dose de 720 g ha-1 foi eficaz no controle de Amaranthus hybridus (100%, Desmodium tortuosum (100%, Bidens pilosa (99%, Eleusine indica (96%, Digitaria horizontalis (100% e Commelina benghalensis (93% aos 21 DAA. Carfentrazone-ethyl aplicado isoladamente controlou eficazmente C. benghalensis. As misturas de glyphosate nas doses de 252 e 720 g ha-1 com carfentrazone-ethyl nas doses de 15 e 30 g ha¹ demonstraram efeito aditivo no controle de A. hybridus, D. tortuosum e Bidens pilosa, à exceção das misturas de glyphosate na dose de 252 g ha-1 com as doses de 15 e 30 g ha-1 de carfentrazone-ethyl, que proporcionam efeito sinergístico no controle de D. tortuosum. A adição das duas doses de carfentrazone-ethyl antagonizou o efeito de glyphosate na menor dose (252 g ha-1 no controle de E. indica, apresentando, no entanto, efeito aditivo com o glyphosate na maior dose (720 g ha-1. Já para D. horizontalis, as misturas de carfentrazone-ethyl com glyphosate na menor dose (252 g ha-1 apresentaram efeito sinergístico no controle dessa espécie, demonstrando, ainda, efeito aditivo na mistura com glyphosate na dose de 720 g ha-1. A mistura de carfentrazone-ethyl com glyphosate proporcionou efeito aditivo no controle de C. benghalensis, independentemente das combinações de doses avaliadas. Os resultados deste experimento indicam que carfentrazone-ethyl apresenta comportamento diferenciado quanto à interação com glyphosate, dependendo da espécie de planta daninha e da dose dos herbicidas utilizados na mistura em tanque, sendo complementar na mistura em tanque com glyphosate, pois demonstrou efeito antagônico em poucas das combinações estudadas, prevalecendo seu efeito aditivo na mistura com glyphosate, no

  14. Glyphosate induces human breast cancer cells growth via estrogen receptors.

    Science.gov (United States)

    Thongprakaisang, Siriporn; Thiantanawat, Apinya; Rangkadilok, Nuchanart; Suriyo, Tawit; Satayavivad, Jutamaad

    2013-09-01

    Glyphosate is an active ingredient of the most widely used herbicide and it is believed to be less toxic than other pesticides. However, several recent studies showed its potential adverse health effects to humans as it may be an endocrine disruptor. This study focuses on the effects of pure glyphosate on estrogen receptors (ERs) mediated transcriptional activity and their expressions. Glyphosate exerted proliferative effects only in human hormone-dependent breast cancer, T47D cells, but not in hormone-independent breast cancer, MDA-MB231 cells, at 10⁻¹² to 10⁻⁶M in estrogen withdrawal condition. The proliferative concentrations of glyphosate that induced the activation of estrogen response element (ERE) transcription activity were 5-13 fold of control in T47D-KBluc cells and this activation was inhibited by an estrogen antagonist, ICI 182780, indicating that the estrogenic activity of glyphosate was mediated via ERs. Furthermore, glyphosate also altered both ERα and β expression. These results indicated that low and environmentally relevant concentrations of glyphosate possessed estrogenic activity. Glyphosate-based herbicides are widely used for soybean cultivation, and our results also found that there was an additive estrogenic effect between glyphosate and genistein, a phytoestrogen in soybeans. However, these additive effects of glyphosate contamination in soybeans need further animal study.

  15. Glyphosate fate in soils when arriving in plant residues.

    Science.gov (United States)

    Mamy, Laure; Barriuso, Enrique; Gabrielle, Benoît

    2016-07-01

    A significant fraction of pesticides sprayed on crops may be returned to soils via plant residues, but its fate has been little documented. The objective of this work was to study the fate of glyphosate associated to plants residues. Oilseed rape was used as model plant using two lines: a glyphosate-tolerant (GT) line and a non-GT one, considered as a crucifer weed. The effects of different fragmentation degrees and placements in soil of plant residues were tested. A control was set up by spraying glyphosate directly on the soil. The mineralization of glyphosate in soil was slower when incorporated into plant residues, and the amounts of extractable and non-extractable glyphosate residues increased. Glyphosate availability for mineralization increased when the size of plant residues decreased, and as the distribution of plant residues in soil was more homogeneous. After 80 days of soil incubation, extractable (14)C-residues mostly involved one metabolite of glyphosate (AMPA) but up to 2.6% of initial (14)C was still extracted from undecayed leaves as glyphosate. Thus, the trapping of herbicides in plant materials provided a protection against degradation, and crops residues returns may increase the persistence of glyphosate in soils. This pattern appeared more pronounced for GT crops, which accumulated more non-degraded glyphosate in their tissues.

  16. Soil concentration of glyphosate and AMPA under rice cultivation with contrasting levels of fertilization

    Science.gov (United States)

    Rey Montoya, Tania; Micaela Biassoni, María; Graciela Herber, Luciana; De Geronimo, Eduardo; Aparicio, Virginia

    2017-04-01

    Rice (Oryza sativa) is the world's most important crop species and occupies c. 150 mill ha. The province of Corrientes in Argentina leads the national production of rice cultivation. Glyphosate is a non-selective herbicide commonly used to control weeds. The molecule is inactivated once applied due to its adsorption in the soil, and once desorbed is degraded by soil microflora resulting in sarcosine and aminomethylphosphoric acid (AMPA) molecules. The objective of this investigation was to compare glyphosate and AMPA concentration in soil under different levels of fertilization along the growth season of the rice crop. A field experiment following a completely randomized design was carried out with four replicates. We evaluated four levels of fertilization (0-18-40): Control: 0 kg ha-1, Dose 1: 120 kg ha-1, Dose 2: 150 kg ha-1, Dose 3: 180 kg ha-1; and two levels of Glyphosate: with (Gly) or without (No) application. Four sampling moments were defined: pre-sowing (taken as reference), vegetative stage (V4, 30 days after application), in floral primordial differentiation-DPF (80 days post-application), and at physiological maturity-MF (125 days after application). Flooding was applied in V4 after sampling. The method used for determination and quantification was by ultra high-pressure liquid chromatography coupled to ESI UHPLC-MS / MS tandem mass spectrometer (+/-) (Acquit-Quattro Premier). We found that glyphosate and AMPA varied their concentration in soil according to the time of sampling. Detected levels of both molecules at pre-sowing indicate the persistence of this herbicide from earlier crop seasons. The highest concentration was measured in MF followed by V4. Interestingly, AMPA concentration showed higher values in V4 without application compared to the treatment with glyphosate application. On the other hand, in flooded soil both molecules presented a decrease in their concentration probably because of their dilution in water, increasing it again after

  17. Low-Profile Repeater Antenna with Parasitic Elements for On-On-Off WBAN Applications

    Directory of Open Access Journals (Sweden)

    Do-Gu Kang

    2016-01-01

    Full Text Available A low-profile repeater antenna with parasitic elements for on-on-off WBAN applications is proposed. The proposed antenna consists of a planar inverted-F antenna (PIFA, two parasitic elements, and a ground plane with a slot. Due to the slot, the impedance matching of the resonance formed by the PIFA is improved, which makes the proposed antenna operate in the 5.8 GHz industrial, scientific, and medical (ISM band. To cover the 5.2 GHz wireless local area network (WLAN band, a dual resonance characteristic is realized by the slot and the two parasitic elements. The first coupling between the PIFA and the slot not only makes the slot operate as a resonator, but also forms secondary coupling between the slot and the two parasitic elements. The two parasitic elements operate as an additional resonator due to secondary coupling. The antenna has the enhanced near surface radiation in the 5.8 GHz ISM band due to addition of the slot and radiation toward off-body direction in the 5.2 GHz WLAN band. In order to evaluate antenna performance considering the human body effect, the antenna characteristics on a human equivalent phantom are analyzed.

  18. Repeated open application test with methyldibromo glutaronitrile, a multicentre study within the EECDRG.

    Science.gov (United States)

    Gruvberger, B; Andersen, K E; Brandão, F M; Bruynzeel, D P; Bruze, M; Frosch, P J; Goossens, A; Lahti, A; Maibach, H I; Menné, T; Orton, D; Seidenari, S

    2005-01-01

    Contact allergy to and allergic contact dermatitis from methyldibromo glutaronitrile (MDBGN) have frequently been reported. This study was initiated to help determine the optimal patch test preparation for MDBGN. In 51 patients with a doubtful or a positive patch test reaction to at least 1 of 4 test preparations with MDBGN in petrolatum at 1.0% w/w, 0.5%, 0.3% and 0.1%, a repeated open application test (ROAT) with moisturizers with and without MDBGN at 0.03% w/w was performed on the upper arms for 2 weeks. 18 of the 51 (35.3%) patients developed a positive ROAT. In all patients, there was a positive ROAT only to the moisturizer with MDBGN (P < 0.001). A statistically significant association was also found between the patch test reactivity (PTRL) and the outcome of the ROAT (P < 0.001). If only considering those with a PTRL above 0.3%, thus with negative or doubtful test reactions to 0.1% and 0.3%, there were still statistically significantly more patients with a positive ROAT to the moisturizer with MDBGN than to the moisturizer without MDBGN. The study demonstrates that patch testing with MDBGN at 0.3% and 0.1% will miss clinically relevant patch test reactions to MDBGN.

  19. Analyzing repeated measures semi-continuous data, with application to an alcohol dependence study.

    Science.gov (United States)

    Liu, Lei; Strawderman, Robert L; Johnson, Bankole A; O'Quigley, John M

    2016-02-01

    Two-part random effects models (Olsen and Schafer,(1) Tooze et al.(2)) have been applied to repeated measures of semi-continuous data, characterized by a mixture of a substantial proportion of zero values and a skewed distribution of positive values. In the original formulation of this model, the natural logarithm of the positive values is assumed to follow a normal distribution with a constant variance parameter. In this article, we review and consider three extensions of this model, allowing the positive values to follow (a) a generalized gamma distribution, (b) a log-skew-normal distribution, and (c) a normal distribution after the Box-Cox transformation. We allow for the possibility of heteroscedasticity. Maximum likelihood estimation is shown to be conveniently implemented in SAS Proc NLMIXED. The performance of the methods is compared through applications to daily drinking records in a secondary data analysis from a randomized controlled trial of topiramate for alcohol dependence treatment. We find that all three models provide a significantly better fit than the log-normal model, and there exists strong evidence for heteroscedasticity. We also compare the three models by the likelihood ratio tests for non-nested hypotheses (Vuong(3)). The results suggest that the generalized gamma distribution provides the best fit, though no statistically significant differences are found in pairwise model comparisons.

  20. Repeated annual paper mill and alkaline residuals application affects soil metal fractions.

    Science.gov (United States)

    Gagnon, Bernard; Robichaud, Annie; Ziadi, Noura; Karam, Antoine

    2014-03-01

    The application of industrial residuals in agriculture may raise concerns about soil and crop metal accumulation. A complete study using a fractionation scheme would reveal build-up in metal pools occurring after material addition and predict the transformation of metals in soil between the different forms and potential metal release into the environment. An experimental study was conducted from 2000 to 2008 on a loamy soil at Yamachiche, Quebec, Canada, to evaluate the effects of repeated annual addition of combined paper mill biosolids when applied alone or with several liming by-products on soil Cu, Zn, and Cd fractions. Wet paper mill biosolids at 0, 30, 60, or 90 Mg ha and calcitic lime, lime mud, or wood ash, each at 3 Mg ha with 30 Mg paper mill biosolids ha, were surface applied after seeding. The soils were sampled after 6 (soybean [ (L.) Merr.]) and 9 [corn ( L.)] crop years and analyzed using the Tessier fractionation procedure. Results indicated that biosolids addition increased exchangeable Zn and Cd, carbonate-bound Cd, Fe-Mn oxide-bound Zn and Cd, organically bound Cu and Zn, and total Zn and Cd fractions but decreased Fe-Mn oxide-bound Cu in the uppermost 30-cm layer. With liming by-products, there was a shift from exchangeable to carbonate-bound forms. Even with very small metals addition, paper mill and liming materials increased the mobility of soil Zn and Cd after 9 yr of application, and this metal redistribution resulted into higher crop grain concentrations.

  1. Laboratory calibration of a POCIS-like sampler based on molecularly imprinted polymers for glyphosate and AMPA sampling in water.

    Science.gov (United States)

    Berho, Catherine; Claude, Bérengère; Coisy, Emeline; Togola, Anne; Bayoudh, Sami; Morin, Philippe; Amalric, Laurence

    2017-03-01

    For more than 15 years, integrative passive sampling has been successfully used for monitoring contaminants in water, but no passive sampling device exists for strongly polar organic compounds, such as glyphosate. We thus propose a polar organic chemical integrative sampler (POCIS)-like tool dedicated to glyphosate and its main degradation product aminomethylphosphonic acid (AMPA), and describe the laboratory calibration of such a tool for calculating the sampling rates of glyphosate and AMPA. This passive sampler consists of a POCIS with molecularly imprinted polymer as a receiving phase and a polyethersulfone diffusion membrane. The calibration experiment for the POCIS was conducted for 35 days in a continuous water-flow-through exposure system. The calibration results show that the sampling rates are 111 and 122 mL day(-1) for glyphosate and AMPA respectively, highlighting the potential interest in and the applicability of this method for environmental monitoring. The influence of membrane porosity on the glyphosate sampling rate was also tested. Graphical Abstract ᅟ.

  2. Glyphosate: useful, dangerous? To license or to phase out?

    Directory of Open Access Journals (Sweden)

    Karl Ernst v. Mühlendahl, Matthias Otto

    2016-12-01

    Full Text Available Glyphosate, a herbicide blocking an enzyme essential for all plants, but not for animals and humans, has certain advantages as compared to other plant protection products. It is not persistent. Due to the production and application of more than 700.000 tons per year, large portions of mankind are exposed. The International Agency on Research on Cancer (IARC of the World Health Organisation (WHO has looked more closely on glyphosate and has classified it as “probably carcinogenic for humans (2A” The German Bundesamt für Risikobewertung (BfR and the European Food Safety Authority (EFSA have analysed the data and contradict the IARC classification. In this paper, the process of decision finding and essential arguments for the contradictory classification are commented. In the ensuing public discussions, conflicts could have been rationalized if the BfR and the EFSA had offered more transparency regarding their evaluation and had restricted their opinions and their proposals to their genuine task: to propose regulations concerning the risks (which follow from possible hazards.

  3. The repeated homogeneous balance method and its applications to nonlinear partial differential equations

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Xiqiang [Department of Mathematics, Ocean University of China, Qingdao Shandong 266071 (China)] e-mail: zhaodss@yahoo.com.cn; Wang Limin [Shandong University of Technology, Zibo Shandong 255049 (China); Sun Weijun [Shandong University of Technology, Zibo Shandong 255049 (China)

    2006-04-01

    In this letter, a new method, called the repeated homogeneous balance method, is proposed for seeking the traveling wave solutions of nonlinear partial differential equations. The Burgers-KdV equation is chosen to illustrate our method. It has been confirmed that more traveling wave solutions of nonlinear partial differential equations can be effectively obtained by using the repeated homogeneous balance method.

  4. Glyphosate biodegradation by plant growth promoting bacteria and their effect to paddy germination in glyphosate contaminated soil

    Directory of Open Access Journals (Sweden)

    Lutfi Tri Andriani

    2017-10-01

    Full Text Available Glyphosate is the most widely used herbicide in Indonesia. Glyphosate persistence between 55 days to 3 years. Widespread and uncontrolled use can cause weeds to become resistant and residue contaminates the soil and water environment. Due to the residual impact of glyphosate, it is necessary to identify a method that can increase the degradation of glyphosate. Several studies have shown that glyphosate can be degraded by microorganisms (fungi, rhizosphere and endophytic bacteria, some of which are members of plant growth-promoting bacteria. This study used the bacteria Enterobacter cloacae, Enterobacter sp and Pseudomonas fluorescens. These three types of bacteria have growth-promoting properties and potentially increase glyphosate degradation. Results of chromatogram on the residual test of glyphosate in liquid medium and soil containing glyphosate showed that glyphosate residue decreased with the addition of bacterial treatment when compared to control. The percentage of degradation in liquid medium are 96.06%  by Enterobacter cloacae, 57% by Enterobacter spand 93.45%  by Pseudomonas fluorescens.The percentage of degradation in soil medium are 4.32%  by Enterobacter cloacae, 23.49% by Enterobacter spand 12.19% by Pseudomonas fluorescens.A positive result indicates that bacterial growth boosters from the plant (endophyte as well as the area of rooting (rhizosphere have additional potential as biofertilizer, bio stimulant, bio protectant but also as bio degradator pollutants such as the herbicide glyphosate

  5. Tissue deposition of the insect repellent DEET and the sunscreen oxybenzone from repeated topical skin applications in rats.

    Science.gov (United States)

    Fediuk, Daryl J; Wang, Tao; Raizman, Joshua E; Parkinson, Fiona E; Gu, Xiaochen

    2010-12-01

    Insect repellent N,N-diethyl-m-toluamide (DEET) and sunscreen oxybenzone are capable of enhancing skin permeation of each other when applied simultaneously. We carried out a cellular study in rat astrocytes and neurons to assess cell toxicity of DEET and oxybenzone and a 30-day study in Sprague-Dawley rats to characterize skin permeation and tissue disposition of the compounds. Cellular toxicity occurred at 1 µg/mL for neurons and 7-day treatment for astrocytes and neurons. DEET and oxybenzone permeated across the skin to accumulate in blood, liver, and brain after repeated topical applications. DEET disappeared from the application site faster than oxybenzone. Combined application enhanced the disposition of DEET in liver. No overt sign of behavioral toxicity was observed from several behavioral testing protocols. It was concluded that despite measurable disposition of the study compounds in vivo, there was no evidence of neurotoxicological deficits from repeated topical applications of DEET, oxybenzone, or both.

  6. 150 ACUTE TOXICITY OF GLYPHOSATE ON CLARIAS ...

    African Journals Online (AJOL)

    The lethal concentration (LC50) value of glyphosate on fingerlings of Clarias gariepinus was 0.0018 ml/l for 96 ... this to fish as a result of run-off from treated fields to ground water, ... Feeding was stopped 24 hours prior to and during exposure ...

  7. 78 FR 25396 - Glyphosate; Pesticide Tolerances

    Science.gov (United States)

    2013-05-01

    ....2 ppm to fruit, pome, group 11- 10 at 0.2 ppm; cranberry, grape, juneberry, kiwifruit, lingonberry... and existing commodities. iii. Cancer. Based on the data summarized in Unit III.A., EPA has concluded that glyphosate does not pose a cancer risk to humans. Therefore, a dietary exposure assessment for the...

  8. Manejo de Conyza bonariensis resistente ao herbicida glyphosate Management of Glyphosate-resistant Conyza bonariensis

    Directory of Open Access Journals (Sweden)

    J.M. Paula

    2011-03-01

    Full Text Available C. bonariensis (Conyza bonariensis é uma planta daninha da família Asteraceae, amplamente distribuída no Brasil, com presença marcante nos Estados do Rio Grande do Sul e do Paraná. Biótipos de C. bonariensis resistentes ao glyphosate foram identificados nos Estados do Rio Grande do Sul, Paraná e São Paulo. O objetivo deste trabalho foi avaliar o efeito de diferentes manejos de inverno e na pré-semeadura da soja sobre a população de plantas de C. bonariensis resistente ao herbicida glyphosate. Os resultados evidenciaram que a população de C. bonariensis é maior em áreas mantidas sem cultivo (pousio do que naquelas áreas cultivadas com trigo ou aveia-preta durante o inverno. Observou-se que o trigo e a aveia-preta exercem efeito supressor sobre a população de C. bonariensis, proporcionando maior facilidade de controle com herbicida na pré-semeadura da cultura usada em sucessão. O controle de C. bonariensis resistente ao herbicida glyphosate foi satisfatório quando se utilizaram herbicidas pós-emergentes na cultura do trigo e glyphosate + 2,4-D ou glyphosate + diuron + paraquat na pré-semeadura da soja.Horseweed (Conyza bonariensis, which belongs to the Asteraceae family, is a weed species widely spread in Brazil. Horseweed biotypes resistant to glyphosate, the main herbicide used in Roundup Ready soybean fields, were identified in the states of Rio Grande do Sul and Parana. The aim of this study was to evaluate the effect of different winter and pre-sowing management techniques on soybean plant population of C. bonariensis resistant to glyphosate. The results showed that the population of C. bonariensis is larger in areas maintained fallow than in areas planted with wheat or oats during the winter. Wheat and oats were found to exert a suppressive effect on the population of C. bonariensis, providing greater ease of control with herbicide before seeding in the culture used in succession. The control of glyphosate-resistant C

  9. Herbicidas alternativos para controle de biótipos de Conyza bonariensis e C. canadensis resistentes ao glyphosate Alternative herbicides to control glyphosate-resistant biotypes of Conyza bonariensis and C. canadensis

    Directory of Open Access Journals (Sweden)

    M.S. Moreira

    2010-01-01

    Full Text Available Após sucessivos anos, aplicações do herbicida glyphosate em pomares de citros no Estado de São Paulo selecionaram biótipos resistentes de Conyza bonariensis e C. canadensis. Na ocorrência de plantas daninhas resistentes em uma área agrícola, tornam-se necessárias mudanças nas práticas de manejo para obtenção de adequado controle das populações resistentes, bem como para a redução da pressão de seleção sobre outras espécies. Assim, este trabalho foi realizado com o objetivo de identificar herbicidas alternativos para controle de biótipos de Conyza spp. resistentes ao herbicida glyphosate, com aplicações em diferentes estádios fenológicos da planta daninha. Três experimentos foram conduzidos em campo, em pomares de citros em formação, sobre plantas de buva em estádio fenológico de dez folhas e no pré-florescimento. Para plantas no estádio de dez folhas, controle satisfatório foi obtido com aplicações de glyphosate + bromacil + diuron (1.440 + 1.200 + 1.200 g ha-1, glyphosate + atrazina (1.440 + 1.500 g ha-1 e glyphosate + diuron (1.440 + 1.500 g ha-1. Quando em estádio de pré-florescimento de Conyza spp., a aplicação do herbicida amônio-glufosinato, na dose de 400 g ha-1, isolado ou associado a MSMA, bromacil+diuron, metsulfuron, carfentrazone e paraquat, foi a alternativa viável para controle dos biótipos resistentes ao glyphosate.After successive years, glyphosate applications on São Paulo-Brazil citrus orchards selected resistant biotypes of Conyza bonariensis and C. canadensis. The occurrence of herbicide-resistant weed biotypes at some agricultural area makes it necessary to change the management practices to reach effective control of the selected resistant populations, as well as to reduce selection pressure on the other species. Thus, this work aimed to identify the alternative herbicides to control glyphosate-resistant biotypes of Conyza spp., with applications at different weed phenological

  10. Biomonitoring of genotoxic risk in agricultural workers from five colombian regions: association to occupational exposure to glyphosate.

    Science.gov (United States)

    Bolognesi, C; Carrasquilla, G; Volpi, S; Solomon, K R; Marshall, E J P

    2009-01-01

    In order to assess possible human effects associated with glyphosate formulations used in the Colombian aerial spray program for control of illicit crops, a cytogenetic biomonitoring study was carried out in subjects from five Colombian regions, characterized by different exposure to glyphosate and other pesticides. Women of reproductive age (137 persons 15-49 yr old) and their spouses (137 persons) were interviewed to obtain data on current health status, history, lifestyle, including past and current occupational exposure to pesticides, and factors including those known to be associated with increased frequency of micronuclei (MN). In regions where glyphosate was being sprayed, blood samples were taken prior to spraying (indicative of baseline exposure), 5 d after spraying, and 4 mo after spraying. Lymphocytes were cultured and a cytokinesis-block micronucleus cytome assay was applied to evaluate chromosomal damage and cytotoxicity. Compared with Santa Marta, where organic coffee is grown without pesticides, the baseline frequency of binucleated cells with micronuclei (BNMN) was significantly greater in subjects from the other four regions. The highest frequency of BNMN was in Boyaca, where no aerial eradication spraying of glyphosate was conducted, and in Valle del Cauca, where glyphosate was used for maturation of sugar cane. Region, gender, and older age (> or =35 yr) were the only variables associated with the frequency of BNMN measured before spraying. A significant increase in frequency of BNMN between first and second sampling was observed in Narino, Putumayo, and Valle immediately (glyphosate exposure. The increase in frequency of BNMN observed immediately after the glyphosate spraying was not consistent with the rates of application used in the regions and there was no association between self-reported direct contact with eradication sprays and frequency of BNMN. Four months after spraying, a statistically significant decrease in the mean frequency of

  11. Distribuição de glyphosate e acúmulo de nutrientes em biótipos de azevém Glyphosate distribution and nutrient accumulation in ryegrass biotypes

    Directory of Open Access Journals (Sweden)

    E.A. Ferreira

    2008-03-01

    produto.This work aimed to evaluate nutrient accumulation and glyphosate translocation in ryegrass biotypes. Two trials were conducted: in the first, 10 uL of 14C-glyphosate ware applied on the upper side of the first leaf showing completely visible ligule, with ryegrass plants at the three-tiller stage. The amount of glyphosate absorbed, translocated and exudated was evaluated 64 hours after application, by using a liquid scintillation spectrometer. Glyphosate was quantified in the leaf it had been applied, in the tillers, roots and in the nutritive solution the plants were grown. In the second trial, glyphosate was applied on the resistant and the susceptible biotypes at the rate of 480 g L-1. Ten days after application, the shoot and roots were collected and oven-dried and the levels of macronutrients were determined. In the first trial, root exudation was observed in both biotypes, in which the amount of exudated glyphosate was similar and not greater than 5% of the absorbed glyphosate. In the main tiller of the susceptible biotype, a higher concentration of 14C-glyphosate was observed, compared to the resistant one. The resistant biotype showed more glyphosate accumulation in the leaf it had been applied and in the susceptible biotype; most 14-C glyphosate was found in the root system. In the second trial, the susceptible biotype showed less P accumulation than the resistant one. Both the resistant and susceptible biotypes tended to accumulate more total N and inorganic N in the shoot and in the whole plant in the absence of glyphosate, compared to the applied treatments. Both biotypes presented the same absorption capacity and macronutrients accumulation in the absence of the glyphosate.

  12. Glyphosate translocation in hairy fleabane (Conyza bonariensis biotypes Translocação do glyphosate em biótipos de buva (Conyza bonariensis

    Directory of Open Access Journals (Sweden)

    E.A. Ferreira

    2008-01-01

    Full Text Available The objective of this work was to evaluate the translocation of glyphosate in C. bonariensis plants resistant and susceptible to that herbicide. The 14C-glyphosate was mixed with commercial gyhphosate (800 g ha-1 and applied on the center of the adaxial face of a third node leaf, using a micro syringe, and adding 10 µL of a solution with specific activity of 1,400 Bq, 45 days after plant emergence. The concentration of the glyphosate translocated in the plant was evaluated at time intervals of 6, 12, 36 and 72 hours after being applied on the application leaf, stem, roots and leaves. Ten hours after treatment application, the distribution of the product in the application leaf, divided into base, center and apex, was also evaluated by measuring the radiation emitted by 14C-glyphosate in a liquid scintillation spectrometer. Greater glyphosate retention was observed in the resistant biotype leaf, approximately 90% of the total absorbed up to 72 hours. In the susceptible biotype, this value was close to 70% in the same period. Susceptible biotype leaves, stem and roots showed greater concentration of glyphosate, indicating greater translocation efficiency in this biotype. In the resistant biotype, the herbicide accumulated in greater quantity at the apex and center of the application leaf, while in the susceptible biotype greater accumulation was observed at the base and center leaf. Thus, it can be stated that the resistance mechanism is related to the differential translocation of this herbicide in the biotypes.Objetivou-se com este trabalho avaliar a translocação do glyphosate em plantas de C. bonariensis resistentes e suscetíveis a esse herbicida. Para isso aplicou-se o 14C-glyphosate em mistura com glyphosate comercial (800 g ha-1 sobre o centro da face adaxial da folha do terceiro nó, utilizando-se uma microsseringa, adicionando-se 10 µL da calda com atividade específica de 1.400 Bq, aos 45 dias após a emergência da buva. A concentra

  13. Urban and agricultural contribution of annual loads of glyphosate and AMPA towards surface waters at the Orge River catchment scale (France)

    Science.gov (United States)

    Botta, Fabrizio; Chevreuil, Marc; Blanchoud, Hélène

    2010-05-01

    The general use of pesticides in the Orge Basin, located in the southern part of the Paris suburb (France), is damaging surface water quality. Consequently, an increase in the water supply costs is registered by the water supply agencies that are situated downstream the Orge confluence with the Seine River. In this catchment, high uses of glyphosate are registered for fallow fields (upstream part) and for roadway weed control (downstream part). The proportion of glyphosate coming from these two zones was not well known, along with the double source of its metabolite AMPA originated from the degradation of some detergent phosphonates. The aim of this work was firstly to identify the potential sources of glyphosate and AMPA in urban sectors (such as sewerage system inputs) and in agricultural areas and to quantify the origins of urban pesticides pathways towards surface waters at the basin scale. The new approach of this project was to collect information at three different scales to establish a first step of modeling. At the basin scale, 1 year of surface water monitoring at the outlet of the Orge River was useful to establish the inputs towards the Seine River. At the urban catchment scale, the investigations have permitted to record glyphosate and AMPA loads transferred by storm waters and by wastewaters. Loads were estimated during and out of application calendar, in different hydrological conditions such as rainfall with high intensity or dry conditions. Impact of WWTP on surface water was also demonstrated. The third phase of this work was the interpretation of agricultural inputs from two different agricultural catchments of the Orge River. The results showed the impact of urban uses of glyphosate upon the Orge River contamination with annual loads from 100 times higher from the urban zone than from the agricultural one. Storm sewers were recognized to be the main way for glyphosate transfer towards surface waters. A budget of glyphosate and AMPA inputs and

  14. Sensibilidade de estirpes de Bradyrhizobium ao glyphosate

    Directory of Open Access Journals (Sweden)

    Rodrigo Josemar Seminoti Jacques

    2010-02-01

    Full Text Available A aplicação do glyphosate sobre a soja resistente a este herbicida pode causar prejuízos à simbiose com o rizóbio. O objetivo deste trabalho foi avaliar a sensibilidade ao herbicida glyphosate de três estirpes de Bradyrhizobium recomendadas para a produção de inoculantes de sementes de soja no Brasil. Avaliou-se o efeito das concentrações de 0,0; 5,4; 10,8; 21,6 e 43,2 µg L-1 do ingrediente ativo do glyphosate [N-(fosfonometil glicina] no meio YM líquido sobre o crescimento de B. japonicum (estirpe SEMIA 5079 e de B. elkanii (estirpe SEMIA 5019 e estirpe SEMIA 587, por meio de leituras das densidades óticas e geração de curvas de crescimento. As reduções de crescimento na presença da menor concentração do glyphosate foram de 18% para SEMIA 5079, 29% para SEMIA 5019 e de 35% para SEMIA 587, sendo, de modo geral, quanto maior a concentração do herbicida no meio de cultura maior a inibição do crescimen­to. As estirpes apresentaram sensibilidade diferencial somente às concentrações mais baixas do glyphosate; nesse caso, foi possível determinar a seguinte ordem de sensibilidade: SEMIA 587 > SEMIA 5019 > SEMIA 5079. Essa sensibilidade diferencial é dependente da concentração do herbicida, pois na presença de 43,2 µg L-1 todas as estirpes tiveram seu crescimento severamente reduzido, não havendo diferença entre elas.

  15. Glyphosate Dissipation in Different Soils Under No-Till and Conventional Till

    Science.gov (United States)

    Okada, Elena; Costa, Jose Luis; Francisco, Bedmar

    2017-04-01

    Glyphosate is the most used herbicide in Argentina, accounting for 62% of the commercialized pesticides in the market. It is used as a weed controller in chemical fallow under no-till systems, and it is also applied in various genetically modified crops (e.g. soybean, corn, cotton). Though it has a high solubility in water, it tends to adsorb and accumulate in agricultural soils. The description of glyphosate biodegradation in soils with a long term history under agricultural practices is of interest. The main objectives of this work were to compare the dissipation of glyphosate and the accumulation of its metabolite aminomethylphosphonic acid (AMPA) over time in three soils from Argentina. The studied soils belong to areas of high agronomic land use and different edaphoclimatic conditions, situated in Manfredi (MAN), Pergamino (PER) and Paraná (PAR). Soil samples were taken from long-term field trials with a history of more than 16 years under no-till and conventional tillage management. To study glyphosate dissipation in soil under controlled laboratory conditions, 400 g of dry soil sample were placed in 1.5 L flasks. A dose corresponding to 6 L ha-1 of commercial glyphosate ATANOR II® (35.6 % a.i.) was applied on day 0. The dose applied was equivalent to a final concentration in soil of 4000 μg Kg-1 of active ingredient. The moisture of the soil samples was kept at 60 % of the field capacity. Samples were incubated in the dark at a constant temperature of 22°C ± 1°C. A sub-sample of 5 g was taken from each flask at day 0 (after application), 1, 3, 7, 15, 20, 28, 44 and 62. Glyphosate and AMPA in soil samples was extracted with a strong basic solution (100 mM Na2B4O7•10H2O/ 100 mM K3PO4, pH=9) and then derivitazed with FMOC-Cl. Detection and quantification of the compounds was performed by ultra-performance liquid chromatography coupled with a mass spectrometer (UPLC MS/MS). The results showed that forty percent of the applied glyphosate was degraded

  16. Agricultural non-point source pollution of glyphosate and AMPA at a catchment scale

    Science.gov (United States)

    Okada, Elena; Perez, Debora; De Geronimo, Eduardo; Aparicio, Virginia; Costa, Jose Luis

    2017-04-01

    can be attributed to deposition of soil particles that are washed from the field. On the other hand, more than 90 % of the soil samples had glyphosate and AMPA. The highest concentrations were found in the month of June, corresponding to the fallow period were glyphosate is applied as a chemical weed controller in no-till systems. Glyphosate and AMPA detection in groundwater samples was 24% and 35%, respectively. The highest glyphosate levels in groundwater also corresponded to the month of June. Glyphosate occurrence in groundwater was transient, that is, in most of the cases glyphosate was not detected in the subsequent sampling months. The contamination of shallow groundwater (agricultural non-point source pollution in the months of herbicide application, that may contribute to groundwater contamination. This is of extreme relevance in the southeast of the Buenos Aires Province, since the main source of drinking water and irrigation is from groundwater resources

  17. Impact of glyphosate and glyphosate-based herbicides on the freshwater environment.

    Science.gov (United States)

    Annett, Robert; Habibi, Hamid R; Hontela, Alice

    2014-05-01

    Glyphosate [N-(phosphonomethyl) glycine] is a broad spectrum, post emergent herbicide and is among the most widely used agricultural chemicals globally. Initially developed to control the growth of weed species in agriculture, this herbicide also plays an important role in both modern silviculture and domestic weed control. The creation of glyphosate tolerant crop species has significantly increased the demand and use of this herbicide and has also increased the risk of exposure to non-target species. Commercially available glyphosate-based herbicides are comprised of multiple, often proprietary, constituents, each with a unique level of toxicity. Surfactants used to increase herbicide efficacy have been identified in some studies as the chemicals responsible for toxicity of glyphosate-based herbicides to non-target species, yet they are often difficult to chemically identify. Most glyphosate-based herbicides are not approved for use in the aquatic environment; however, measurable quantities of the active ingredient and surfactants are detected in surface waters, giving them the potential to alter the physiology of aquatic organisms. Acute toxicity is highly species dependant across all taxa, with toxicity depending on the timing, magnitude, and route of exposure. The toxicity of glyphosate to amphibians has been a major focus of recent research, which has suggested increased sensitivity compared with other vertebrates due to their life history traits and reliance on both the aquatic and terrestrial environments. This review is designed to update previous reviews of glyphosate-based herbicide toxicity, with a focus on recent studies of the aquatic toxicity of this class of chemicals.

  18. Fenologia da trapoeraba como indicador para tolerância ao herbicida glyphosate Phenology of bengal dayflower as indicator of glyphosate tolerance

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    A.C.R Dias

    2013-03-01

    Full Text Available Rotineiramente, tem sido desconsiderada a contribuição do estádio de desenvolvimento das espécies de plantas daninhas nas análises de tolerância ou resistência a herbicidas, o que pode resultar em divergências entre a pesquisa teórica e a aplicação prática dos dados. Nesse sentido, este trabalho foi desenvolvido com o objetivo de avaliar a resposta biológica da trapoeraba (Commelina benghalensis, comparativamente ao capim-marmelada (Brachiaria plantaginea, a aplicações de doses do herbicida glyphosate, em seis estádios fenológicos. Dois experimentos foram desenvolvidos em casa de vegetação, submetendo-se plantas de trapoeraba e capim-marmelada ao esquema fatorial de tratamentos 9 x 6, em que nove foram as doses de glyphosate e seis foram os estádios fenológicos das plantas daninhas, variáveis entre a emissão da primeira folha definitiva e o início do florescimento. Por meio do emprego de curvas de dose-resposta e de regressões polinomiais, concluiu-se que o estádio de desenvolvimento da trapoeraba contribui significativamente para o grau de tolerância da espécie ao herbicida glyphosate, de modo que, comparativamente ao capim-marmelada, plantas de trapoeraba tornam-se quatro vezes mais tolerantes ao glyphosate a cada dez unidades de desenvolvimento fenológico na escala BBCH. Essas considerações possuem importante aplicabilidade prática, justificando medidas de controle químico em estádios iniciais do crescimento da trapoeraba.The importance of the phenological development of weeds has been frequently ignored when analyzing plant-herbicide tolerance or resistance, what may result on divergences between theoretical research and practical data application. Thus, this work was carried out to evaluate the biological response of Bengal dayflower (Commelina benghalensis, comparatively to alexandergrass (Brachiaria plantaginea, to the application of different rates of glyphosate, at six phenological stages. Two

  19. Persistence of the herbicide butachlor in soil after repeated applications and its effects on soil microbial functional diversity.

    Science.gov (United States)

    Fang, Hua; Yu, Yun L; Wang, Xiu G; Chu, Xiao Q; Yang, Xiao E

    2009-02-01

    Effects of repeated applications of the herbicide butachlor (N-(butoxymethyl)-2-chloro -N-2',6'-dimethyl acetanilide) in soil on its persistence and soil microbial functional diversity were investigated under laboratory conditions. The degradation half-lives of butachlor at the recommended dosage in soil were calculated to be 12.5, 4.5, and 3.2 days for the first, second, and third applications, respectively. Throughout this study, no significant inhibition of the Shannon-Wiener index H' was observed. However, the Simpson index 1/D and McIntosh index U were significantly reduced (P butachlor, and thereafter gradually recovered to a similar level to that of the control soil. A similar variation but faster recovery in 1/D and U was observed after the second and third Butachlor applications. Therefore, repeated applications of butachlor led to more rapid degradation of the herbicide, and more rapid recovery of soil microorganisms. It is concluded that repeated butachlor applications in soil had a temporary or short-term inhibitory effect on soil microbial communities.

  20. A tandem repeats database for bacterial genomes: application to the genotyping of Yersinia pestis and Bacillus anthracis

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    Denoeud France

    2001-03-01

    Full Text Available Abstract Background Some pathogenic bacteria are genetically very homogeneous, making strain discrimination difficult. In the last few years, tandem repeats have been increasingly recognized as markers of choice for genotyping a number of pathogens. The rapid evolution of these structures appears to contribute to the phenotypic flexibility of pathogens. The availability of whole-genome sequences has opened the way to the systematic evaluation of tandem repeats diversity and application to epidemiological studies. Results This report presents a database (http://minisatellites.u-psud.fr of tandem repeats from publicly available bacterial genomes which facilitates the identification and selection of tandem repeats. We illustrate the use of this database by the characterization of minisatellites from two important human pathogens, Yersinia pestis and Bacillus anthracis. In order to avoid simple sequence contingency loci which may be of limited value as epidemiological markers, and to provide genotyping tools amenable to ordinary agarose gel electrophoresis, only tandem repeats with repeat units at least 9 bp long were evaluated. Yersinia pestis contains 64 such minisatellites in which the unit is repeated at least 7 times. An additional collection of 12 loci with at least 6 units, and a high internal conservation were also evaluated. Forty-nine are polymorphic among five Yersinia strains (twenty-five among three Y. pestis strains. Bacillus anthracis contains 30 comparable structures in which the unit is repeated at least 10 times. Half of these tandem repeats show polymorphism among the strains tested. Conclusions Analysis of the currently available bacterial genome sequences classifies Bacillus anthracis and Yersinia pestis as having an average (approximately 30 per Mb density of tandem repeat arrays longer than 100 bp when compared to the other bacterial genomes analysed to date. In both cases, testing a fraction of these sequences for

  1. Efficacy of ‘hack and squirt’ application of imazapyr, triclopyr, and glyphosate to control the invasive tree species Chinese tallowtree

    Science.gov (United States)

    Charles A. Gresham

    2010-01-01

    In May 2005, 12 plots approximately 21 by 27 m each were established on the exterior bank of a dredge spoil area in Georgetown, SC. The tree cover was primarily Chinese tallowtree, but there were also live oak trees in each plot. Also in May 2005, Chinese tallowtree s (d.b.h. > 2.4 cm) in three randomly selected plots received a ‘hack and squirt’ application of...

  2. Evaluating exposure and potential effects on honeybee brood (Apis mellifera) development using glyphosate as an example

    Science.gov (United States)

    Thompson, Helen M; Levine, Steven L; Doering, Janine; Norman, Steve; Manson, Philip; Sutton, Peter; von Mérey, Georg

    2014-01-01

    This study aimed to develop an approach to evaluate potential effects of plant protection products on honeybee brood with colonies at realistic worst-case exposure rates. The approach comprised 2 stages. In the first stage, honeybee colonies were exposed to a commercial formulation of glyphosate applied to flowering Phacelia tanacetifolia with glyphosate residues quantified in relevant matrices (pollen and nectar) collected by foraging bees on days 1, 2, 3, 4, and 7 postapplication and glyphosate levels in larvae were measured on days 4 and 7. Glyphosate levels in pollen were approximately 10 times higher than in nectar and glyphosate demonstrated rapid decline in both matrices. Residue data along with foraging rates and food requirements of the colony were then used to set dose rates in the effects study. In the second stage, the toxicity of technical glyphosate to developing honeybee larvae and pupae, and residues in larvae, were then determined by feeding treated sucrose directly to honeybee colonies at dose rates that reflect worst-case exposure scenarios. There were no significant effects from glyphosate observed in brood survival, development, and mean pupal weight. Additionally, there were no biologically significant levels of adult mortality observed in any glyphosate treatment group. Significant effects were observed only in the fenoxycarb toxic reference group and included increased brood mortality and a decline in the numbers of bees and brood. Mean glyphosate residues in larvae were comparable at 4 days after spray application in the exposure study and also following dosing at a level calculated from the mean measured levels in pollen and nectar, showing the applicability and robustness of the approach for dose setting with honeybee brood studies. This study has developed a versatile and predictive approach for use in higher tier honeybee toxicity studies. It can be used to realistically quantify exposure of colonies to pesticides to allow the

  3. Cana-de-açúcar: avaliação da taxa de aplicação e deposição do herbicida glifosato Sugarcane: evaluation of application rates and deposition of the glyphosate herbicide

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    Euripedes B. Rodrigues

    2011-01-01

    Full Text Available No Brasil, o uso de agrotóxicos consumirá, anualmente, mais de seis milhões de m3 de água como veículo, na cultura da cana-de-açúcar. O menor volume de calda aumenta a autonomia e a capacidade operacional dos pulverizadores, diminuindo o risco de perdas por escorrimento. Este trabalho teve como objetivo comparar diferentes taxas de aplicação do glifosato quanto à eficiência no controle e à deposição da calda em plantas daninhas na operação de “repasse” ou “catação”. Foram executados oito tratamentos com quatro repetições distribuídos em blocos ao acaso. As taxas de aplicação avaliadas foram: 8,8, 73, 96,7, 190, 260, 380 e 467 L ha-1, aplicadas com equipamentos costal de acionamento manual, costal pressurizado e micronizador rotativo tipo CDA. Realizou-se a eficiência no controle das plantas daninhas considerando-se o efeito das aplicações em cada um dos tratamentos. A avaliação qualitativa, comparando-se os depósitos obtidos em cada um dos tratamentos, foi feita pela pulverização sobre as plantas daninhas de uma solução de água e cloreto de sódio com os mesmos equipamentos e nas mesmas condições. Os resultados indicam a possibilidade de utilização de menores volumes de aplicação sem prejuízo da qualidade.The growing use of pesticides in agriculture will consume more than six million cubic meters of water annually in Brazil, on sugarcane crop alone. The minor volumes of water can give an increase in autonomy and capacity of sprayer, and reduces the chance of loss by runoff. This work has the purpose to compare different rates of the glyphosate herbicide application, concerning efficiency of control and volume deposition on weeds, at operations of “repass” on sugarcane crop. Eight treatments with four replications were studied in randomized blocks. Application rates evaluated were: 8.8, 73, 96.7, 190, 260, 380 and 467 L ha-1, using a pressurized knapsack sprayer and another with hand operation

  4. Crescimento e morfoanatomia foliar de eucalipto sob efeito de deriva do glyphosate Leaf growth and morphoanatomy of eucalypt under the effect of glyphosate drift

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    L.D. Tuffi Santos

    2005-03-01

    -se aumento na espessura do limbo e do PPA submetidos a 345,6 g e.a. ha¹ de glyphosate, enquanto o PLA e a EAD demonstraram acréscimo na espessura somente aos 15 DAA sob a mesma dosagem. As doses de 172,8 e 345,6 g e.a. ha-1 de glyphosate promoveram aumento na espessura do limbo e do PPA aos 15 DAA. O aumento na espessura do limbo é resultante da expansão das células do parênquima paliçádico, podendo estar relacionado à resposta das plantas à perda de área foliar específica, bem como à síntese de compostos secundários, como celulases, provocados pela ação do glyphosate.The effects of glyphosate drift during application are harmful to the eucalypt culture. This work evaluated the effects of simulated glyphosate drift on leaf growth and morphoanatomy of the clone 15-CENIBRA (Eucalyptus urophylla X E. grandis. A randomized block design was used with four replications. Each experimental plot was represented by one plant cultivated in a 10 liter pot with soil. The treatments were 0; 43.2; 86.4; 172.8 and 34.6 g a.e. ha-1 of glyphosate, applied 40 days after seedling planting with a precision sprayer, so that the upper third of the plants was unaffected. The morphological alterations in the plant shoot were described .Intoxication percentage in relation to the control was evaluated 7, 15, and 30 days after application (DAA. Leaves were collected from the third node of the first basal branch of the plants, fixed in FAA50 and stored in 70% ethanol 7 and 15 DAA. Cross section of the intermediate region was stained with astra blue and basic fuchsia and installed on permanent slides to measure thickness, of the palisade (PPA and spongy (PLA parenchyma, epidermis of the adaxial (EAD and abaxial (EAB sides, as well as the proportion of each tissue area using software "Image-Pro Plus". From the 5th DAA, leaf wilt, chlorosis and curling were observed in the plant apices sprayed with 17.8 and 345.6 g a.e. ha¹ of glyphosate. The plants subjected to 24% of the rate attained

  5. Eficiência de glyphosate no controle de Commelina benghalensis e Commelina diffusa Efficiency of glyphosate in the control of Commelina benghalensis and Commelina diffusa

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    I.C. Santos

    2001-04-01

    is repeatedly applied to control weeds, but Commelina benghalensis and C. diffusa have not been successfully controlled. To confirm such fact and to verify the effect of increasing doses of glyphosate (720, 1,400, 2,160, 2,880 and 3,600 g a.i. ha-1 on these weed species, an experiment was installed in a randomized block design with six replications. The rates of herbicide were applied in the flowering period of plants grown in polyethylene boxes 10 cm high, 27.5 cm wide and 39.5 cm long, in unprotected environment. The effectiveness of the treatments was evaluated through the percentage of weed control related to the check treatment (no herbicide, and by the shoot dry biomass that survived the treatments. C. benghalensis was efficiently controlled by glyphosate, but C. diffusa presented herbicide tolerance. The control of C. benghalensis was above 94%, starting from the smallest rate, 25 days after treatments (DAT, and it was 100% in all the doses at 63 DAT. For C. diffusa, in general, as the doses of glyphosate increased, the shoot dry biomass became smaller. However, even with the three higher doses, when up to 98.3% of control at 46 DAT was observed, plant recovery occurred at 88 DAT. Under the conditions of this experiment, glyphosate provided an excellent control of C. benghalensis starting from 720 g a.i. ha-1, 25 DAT. However, excellent control of C. diffusa for over 60 DAT was only achieved with glyphosate rate starting from 2.880 g a.i. ha-1.

  6. Determination of Glyphosate Levels in Breast Milk Samples from Germany by LC-MS/MS and GC-MS/MS

    NARCIS (Netherlands)

    Steinborn, Angelika; Alder, Lutz; Michalski, Britta; Zomer, Paul; Bendig, Paul; Martinez, Sandra Aleson; Mol, Hans G.J.; Class, Thomas J.; Costa Pinheiro, Nathalie

    2016-01-01

    This study describes the validation and application of two independent analytical methods for the determination of glyphosate in breast milk. They are based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively. For L

  7. Determination of Glyphosate Levels in Breast Milk Samples from Germany by LC-MS/MS and GC-MS/MS

    NARCIS (Netherlands)

    Steinborn, Angelika; Alder, Lutz; Michalski, Britta; Zomer, Paul; Bendig, Paul; Martinez, Sandra Aleson; Mol, Hans G.J.; Class, Thomas J.; Costa Pinheiro, Nathalie

    2016-01-01

    This study describes the validation and application of two independent analytical methods for the determination of glyphosate in breast milk. They are based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively. For L

  8. Fate and availability of glyphosate and AMPA in agricultural soil.

    Science.gov (United States)

    Simonsen, Louise; Fomsgaard, Inge S; Svensmark, Bo; Spliid, Niels Henrik

    2008-06-01

    The fate of glyphosate and its degradation product aminomethylphosphonic acid (AMPA) was studied in soil. Labeled glyphosate was used to be able to distinguish the measured quantities of glyphosate and AMPA from the background values since the soil was sampled in a field where glyphosate had been used formerly. After addition of labeled glyphosate, the disappearance of glyphosate and the formation and disappearance of AMPA were monitored. The resulting curves were fitted according to a new EU guideline. The best fit of the glyphosate degradation data was obtained using a first-order multi compartment (FOMC) model. DT(50) values of 9 days (glyphosate) and 32 days (AMPA) indicated relatively rapid degradation. After an aging period of 6 months, the leaching risk of each residue was determined by treating the soil with pure water or a phosphate solution (pH 6), to simulate rain over a non-fertilized or fertilized field, respectively. Significantly larger (p glyphosate and AMPA were extracted from the soil when phosphate solution was used as an extraction agent, compared with pure water. This indicates that the risk of leaching of aged glyphosate and AMPA residues from soil is greater in fertilized soil. The blank soil, to which 252 g glyphosate/ha was applied 21 months before this study, contained 0.81 ng glyphosate/g dry soil and 10.46 ng AMPA/g dry soil at the start of the study. Blank soil samples were used as controls without glyphosate addition. After incubation of the blank soil samples for 6 months, a significantly larger amount of AMPA was extracted from the soil treated with phosphate solution than from that treated with pure water. To determine the degree of uptake of aged glyphosate residues by crops growing in the soil, (14)C-labeled glyphosate was applied to soil 6.5 months prior to sowing rape and barley seeds. After 41 days, 0.006 +/- 0.002% and 0.005 +/- 0.001% of the applied radioactivity was measured in rape and barley, respectively.

  9. Toxicity of formulated glyphosate (glyphos) and cosmo-flux to larval Colombian frogs 1. Laboratory acute toxicity.

    Science.gov (United States)

    Bernal, M H; Solomon, K R; Carrasquilla, G

    2009-01-01

    The spraying of coca (Erythroxylum coca) with glyphosate in Colombia has raised concerns about possible impacts on amphibians. There are few toxicity data for species other than those from temperate regions, and these have not been generated with the combination of formulated glyphosate (Glyphos) and the adjuvant, Cosmo-Flux (coca mix) as used in coca control in Colombia. In order to characterize toxicity of the spray mixture to frogs from Colombia, Gosner stage-25 tadpoles of Scinax ruber, Dendropophus microcephalus, Hypsiboas crepitans, Rhinella granulosa, Rhinella marina, Rhinella typhonius, Centrolene prosoblepon, and Engystomops pustulosus were exposed to the coca mix at concentrations of glyphosate ranging from 1 to 4.2 mg a.e./L diluted in dechlorinated tap water in glass containers. Cosmo-Flux was added to Glyphos in the proportion of 2.3% v/v, as used in aerial application for coca control. Exposures were for 96 h at 23 +/- 1.5 degrees C with 12:12-h light/dark cycle. Test solutions were renewed every 24 h. Concentrations, measured within the first hour and at 24 and 96 h using enzyme-linked immunosorbent assay (ELISA) (Abraxis, LLC), ranged from 70 to 130% of nominal values. LC50 values ranged from 1200 to 2780 microg glyphosate acid equivalents (a.e.)/L for the 8 species tested. Data suggest that sensitivity to Roundup-type formulations of glyphosate in these species is similar to that observed in other tropical and temperate species. In addition, sensitivity of larval amphibians to Roundup-type formulations spans a relatively narrow range. Finally, toxicity of the mixture as used to spray coca was likely driven by the surfactant in the glyphosate formulation, as the addition of Cosmo-Flux did not enhance toxicity above those reported for Vision = Roundup.

  10. Resposta de varjão (Parkia multijuga a subdoses de glyphosate Response of varjão (Parkia multijuga seedlings to reduced glyphosate rates

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    O.M. Yamashita

    2006-09-01

    -month-old plants by observing plant toxicity, plant height, stem diameter, and leaf number. A control was also used without herbicide application to compare the effects. Under the conditions of this experiment, Varjão presented tolerance to and ability to recover from glyphosate up to the rate of 360 g ha-1. Higher rates delayed plant development. The damage caused by glyphosate drift in these plants was directly proportional to rate increase. The symptoms included leaf fall, compromising plant growth.

  11. Tandem repeat regions within the Burkholderia pseudomallei genome and their application for high resolution genotyping

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    Harvey Steven P

    2007-03-01

    Full Text Available Abstract Background The facultative, intracellular bacterium Burkholderia pseudomallei is the causative agent of melioidosis, a serious infectious disease of humans and animals. We identified and categorized tandem repeat arrays and their distribution throughout the genome of B. pseudomallei strain K96243 in order to develop a genetic typing method for B. pseudomallei. We then screened 104 of the potentially polymorphic loci across a diverse panel of 31 isolates including B. pseudomallei, B. mallei and B. thailandensis in order to identify loci with varying degrees of polymorphism. A subset of these tandem repeat arrays were subsequently developed into a multiple-locus VNTR analysis to examine 66 B. pseudomallei and 21 B. mallei isolates from around the world, as well as 95 lineages from a serial transfer experiment encompassing ~18,000 generations. Results B. pseudomallei contains a preponderance of tandem repeat loci throughout its genome, many of which are duplicated elsewhere in the genome. The majority of these loci are composed of repeat motif lengths of 6 to 9 bp with 4 to 10 repeat units and are predominately located in intergenic regions of the genome. Across geographically diverse B. pseudomallei and B.mallei isolates, the 32 VNTR loci displayed between 7 and 28 alleles, with Nei's diversity values ranging from 0.47 and 0.94. Mutation rates for these loci are comparable (>10-5 per locus per generation to that of the most diverse tandemly repeated regions found in other less diverse bacteria. Conclusion The frequency, location and duplicate nature of tandemly repeated regions within the B. pseudomallei genome indicate that these tandem repeat regions may play a role in generating and maintaining adaptive genomic variation. Multiple-locus VNTR analysis revealed extensive diversity within the global isolate set containing B. pseudomallei and B. mallei, and it detected genotypic differences within clonal lineages of both species that were

  12. Glyphosate and AMPA content in the PM10 emitted by a soil of the central semiarid region of Argentine (CSRA)

    Science.gov (United States)

    Mendez, Mariano; Aimar, Silvia; Aparicio, Virginia; Buschiazzo, Daniel; De Geronimo, Eduardo; Costa, Jose Luis

    2017-04-01

    150 ppb, while than in PM10 emitted by them ranged between 520 ppb and 750 ppb. The enrichment ratio (ER, quotient between concentration or content in PM10 and aggregates) of glyphosate and AMPA (between 4 and 17) were higher than ER of clay and OM (between 1 and 3). ERglyphosate and ERAMPA were different among aggregate fractions (p19.2 (ERglyphosate = 17 and ERAMPA = 10). Our results showed contents variable of glyphosate and AMPA in the soil and its aggregate fractions after 12 month from the last glyphosate application in a haplustoll soil of the CSRA. High glyphosate content were also found in PM10 emitted by the soil and its aggregate fractions. More studies are necessary to evaluate the glyphosate content in PM10 and its potential impact in the heath.

  13. Differentiating glyphosate-resistant and glyphosate-sensitive Italian ryegrass using hyperspectral imagery

    Science.gov (United States)

    Lee, Matthew A.; Huang, Yanbo; Nandula, Vijay K.; Reddy, Krishna N.

    2014-05-01

    Glyphosate based herbicide programs are most preferred in current row crop weed control practices. With the increased use of glyphosate, weeds, including Italian ryegrass (Lolium multiflorum), have developed resistance to glyphosate. The identification of glyphosate resistant weeds in crop fields is critical because they must be controlled before they reduce the crop yield. Conventionally, the method for the identification with whole plant or leaf segment/disc shikimate assays is tedious and labor-intensive. In this research, we investigated the use of high spatial resolution hyperspectral imagery to extract spectral curves derived from the whole plant of Italian ryegrass to determine if the plant is glyphosate resistant (GR) or glyphosate sensitive (GS), which provides a way for rapid, non-contact measurement for differentiation between GR and GS weeds for effective site-specific weed management. The data set consists of 226 greenhouse grown plants (119 GR, 107 GS), which were imaged at three and four weeks after emergence. In image preprocessing, the spectral curves are normalized to remove lighting artifacts caused by height variation in the plants. In image analysis, a subset of hyperspectral bands is chosen using a forward selection algorithm to optimize the area under the receiver operating characteristic (ROC) between GR and GS plants. Then, the dimensionality of selected bands is reduced using linear discriminant analysis (LDA). Finally, the maximum likelihood classification was conducted for plant sample differentiation. The results show that the overall classification accuracy is between 75% and 80% depending on the age of the plants. Further refinement of the described methodology is needed to correlate better with plant age.

  14. Levels of glyphosate in surface waters, sediments and soils associated with direct sowing soybean cultivation in north pampasic region of Argentina.

    Science.gov (United States)

    Peruzzo, Pablo J; Porta, Atilio A; Ronco, Alicia E

    2008-11-01

    Levels of glyphosate were determined in water, soil and sediment samples from a transgenic soybean cultivation area located near to tributaries streams of the Pergamino-Arrecifes system in the north of the Province of Buenos Aires, Argentina. Field work took into account both the pesticide application and the rains occurring after applications. The pesticide was analysed by HPLC-UV detection, previous derivatization with 9-fluorenylmethylchloroformate (FMOC-Cl). In addition, SoilFug multimedia model was used to analyse the environmental distribution of the pesticides. In the field, levels of glyphosate in waters ranged from 0.10 to 0.70 mg/L, while in sediments and soils values were between 0.5 and 5.0 mg/Kg. Temporal variation of glyphosate levels depended directly on the time of application and the rain events. The results obtained from the application of the model are in accordance with the values found in the field.

  15. Molybdenum mixed with glyphosate and alone via foliar spray in no-tillage common bean grown on corn stover

    Directory of Open Access Journals (Sweden)

    Gessimar Nunes Camelo

    2014-02-01

    Full Text Available The effect of molybdenum (Mo on common bean grown in desiccated corn stover in a no-tillage system was evaluated under two application modes: Mo mixed with the desiccant glyphosate and Mo direct spray to the bean leaves. The treatments (four replicates were assigned to a completely randomized block design in a split-plot arrangement with the application of Mo (0, 100, 200, 400 and 800 g ha-1 mixed with glyphosate in the main plots and Mo foliar spray (0 and 100 g ha-1 in the sub-plots. The field experiments were carried out in 2009 and 2010 in the municipality of Coimbra, Minas Gerais State, with the common bean cultivar Ouro Vermelho. Mo mixed with glyphosate had neither an effect on common bean yield nor on the Mo and N contents in leaves, however it increased the Mo and N contents in seeds. Application of Mo via foliar spray increased Mo content in leaves and Mo and N contents in seeds. The reapplication of molybdenum with glyphosate for desiccation in subsequent crops caused a cumulative effect of Mo content in bean seeds.

  16. Dessecação de plantas daninhas com glyphosate em mistura com ureia ou sulfato de amônio Weed desiccation with glyphosate mixed with urea or ammonium sulfate

    Directory of Open Access Journals (Sweden)

    S.J.P. Carvalho

    2009-06-01

    Full Text Available O glyphosate é um herbicida não-seletivo, sistêmico, usado para controle de plantas daninhas anuais e perenes em todo o mundo. A absorção da molécula do glyphosate ocorre pelos tecidos fotossinteticamente ativos das plantas, porém alguns fatores podem reduzir sua eficácia, como a morfologia e diversidade de espécies, chuva após aplicação, qualidade da água e misturas em tanque com outros defensivos, entre outros. Objetivou-se com este trabalho avaliar a influência da adição de sulfato de amônio ou ureia em calda na eficácia do herbicida glyphosate para dessecação de plantas daninhas. Dois experimentos foram desenvolvidos em Piracicaba - SP, com aplicações de glyphosate (720 e 1.440 g ha-1 isolado ou combinado com duas doses de sulfato de amônio (7,5 e 15,0 g L-1 ou ureia (2,5 e 5,0 g L-1 sobre as plantas daninhas: apaga-fogo (Alternanthera tenella e capim-massambará (Sorghum halepense. Para a espécie menos suscetível ao herbicida (capim-massambará, a adição de fontes nitrogenadas à menor dose de glyphosate acelerou a morte das plantas, elevando os níveis de controle em até 7,3% na avaliação de 21 dias após aplicação (DAA dos tratamentos. Contudo, os efeitos não foram observados nas avaliações de controle, massa fresca e seca, conduzidas aos 28 DAA. A dose recomendada de glyphosate para cada espécie proporcionou controle satisfatório, sem a necessidade de adição de sulfato de amônio ou ureia.Glyphosate is a non-selective systemic herbicide used to control annual and perennial weeds worldwide. Molecule absorption occurs through the plant's photosynthetically-active tissues; however, some factors might reduce its efficacy, such as morphology and specific diversity, rain after application, water quality and tank mixtures with other chemicals. Thus, this work aimed to evaluate the influence of ammonium sulfate or urea addiction to spray tank on glyphosate efficacy for weed desiccation. Two trials were

  17. Repeatability in computer-aided diagnosis: application to breast cancer diagnosis on sonography.

    Science.gov (United States)

    Drukker, Karen; Pesce, Lorenzo; Giger, Maryellen

    2010-06-01

    The aim of this study was to investigate the concept of repeatability in a case-based performance evaluation of two classifiers commonly used in computer-aided diagnosis in the task of distinguishing benign from malignant lesions. The authors performed .632+ bootstrap analyses using a data set of 1251 sonographic lesions of which 212 were malignant. Several analyses were performed investigating the impact of sample size and number of bootstrap iterations. The classifiers investigated were a Bayesian neural net (BNN) with five hidden units and linear discriminant analysis (LDA). Both used the same four input lesion features. While the authors did evaluate classifier performance using receiver operating characteristic (ROC) analysis, the main focus was to investigate case-based performance based on the classifier output for individual cases, i.e., the classifier outputs for each test case measured over the bootstrap iterations. In this case-based analysis, the authors examined the classifier output variability and linked it to the concept of repeatability. Repeatability was assessed on the level of individual cases, overall for all cases in the data set, and regarding its dependence on the case-based classifier output. The impact of repeatability was studied when aiming to operate at a constant sensitivity or specificity and when aiming to operate at a constant threshold value for the classifier output. The BNN slightly outperformed the LDA with an area under the ROC curve of 0.88 versus 0.85 (p 90%) and low specificity (clinical decision making.

  18. Multiple Myeloma and Glyphosate Use: A Re-Analysis of US Agricultural Health Study (AHS) Data

    Science.gov (United States)

    Sorahan, Tom

    2015-01-01

    A previous publication of 57,311 pesticide applicators enrolled in the US Agricultural Health Study (AHS) produced disparate findings in relation to multiple myeloma risks in the period 1993–2001 and ever-use of glyphosate (32 cases of multiple myeloma in the full dataset of 54,315 applicators without adjustment for other variables: rate ratio (RR) 1.1, 95% confidence interval (CI) 0.5 to 2.4; 22 cases of multiple myeloma in restricted dataset of 40,719 applicators with adjustment for other variables: RR 2.6, 95% CI 0.7 to 9.4). It seemed important to determine which result should be preferred. RRs for exposed and non-exposed subjects were calculated using Poisson regression; subjects with missing data were not excluded from the main analyses. Using the full dataset adjusted for age and gender the analysis produced a RR of 1.12 (95% CI 0.50 to 2.49) for ever-use of glyphosate. Additional adjustment for lifestyle factors and use of ten other pesticides had little effect (RR 1.24, 95% CI 0.52 to 2.94). There were no statistically significant trends for multiple myeloma risks in relation to reported cumulative days (or intensity weighted days) of glyphosate use. The doubling of risk reported previously arose from the use of an unrepresentative restricted dataset and analyses of the full dataset provides no convincing evidence in the AHS for a link between multiple myeloma risk and glyphosate use. PMID:25635915

  19. Multiple myeloma and glyphosate use: a re-analysis of US Agricultural Health Study (AHS) data.

    Science.gov (United States)

    Sorahan, Tom

    2015-01-28

    A previous publication of 57,311 pesticide applicators enrolled in the US Agricultural Health Study (AHS) produced disparate findings in relation to multiple myeloma risks in the period 1993-2001 and ever-use of glyphosate (32 cases of multiple myeloma in the full dataset of 54,315 applicators without adjustment for other variables: rate ratio (RR) 1.1, 95% confidence interval (CI) 0.5 to 2.4; 22 cases of multiple myeloma in restricted dataset of 40,719 applicators with adjustment for other variables: RR 2.6, 95% CI 0.7 to 9.4). It seemed important to determine which result should be preferred. RRs for exposed and non-exposed subjects were calculated using Poisson regression; subjects with missing data were not excluded from the main analyses. Using the full dataset adjusted for age and gender the analysis produced a RR of 1.12 (95% CI 0.50 to 2.49) for ever-use of glyphosate. Additional adjustment for lifestyle factors and use of ten other pesticides had little effect (RR 1.24, 95% CI 0.52 to 2.94). There were no statistically significant trends for multiple myeloma risks in relation to reported cumulative days (or intensity weighted days) of glyphosate use. The doubling of risk reported previously arose from the use of an unrepresentative restricted dataset and analyses of the full dataset provides no convincing evidence in the AHS for a link between multiple myeloma risk and glyphosate use.

  20. Multiple Myeloma and Glyphosate Use: A Re-Analysis of US Agricultural Health Study (AHS Data

    Directory of Open Access Journals (Sweden)

    Tom Sorahan

    2015-01-01

    Full Text Available A previous publication of 57,311 pesticide applicators enrolled in the US Agricultural Health Study (AHS produced disparate findings in relation to multiple myeloma risks in the period 1993–2001 and ever-use of glyphosate (32 cases of multiple myeloma in the full dataset of 54,315 applicators without adjustment for other variables: rate ratio (RR 1.1, 95% confidence interval (CI 0.5 to 2.4; 22 cases of multiple myeloma in restricted dataset of 40,719 applicators with adjustment for other variables: RR 2.6, 95% CI 0.7 to 9.4. It seemed important to determine which result should be preferred. RRs for exposed and non-exposed subjects were calculated using Poisson regression; subjects with missing data were not excluded from the main analyses. Using the full dataset adjusted for age and gender the analysis produced a RR of 1.12 (95% CI 0.50 to 2.49 for ever-use of glyphosate. Additional adjustment for lifestyle factors and use of ten other pesticides had little effect (RR 1.24, 95% CI 0.52 to 2.94. There were no statistically significant trends for multiple myeloma risks in relation to reported cumulative days (or intensity weighted days of glyphosate use. The doubling of risk reported previously arose from the use of an unrepresentative restricted dataset and analyses of the full dataset provides no convincing evidence in the AHS for a link between multiple myeloma risk and glyphosate use.

  1. Variation in glyphosate and AMPA concentrations of surface water and groundwater

    Science.gov (United States)

    Caprile, Ana Clara; Aparicio, Virginia; Sasal, Carolina; Andriulo, Enrique

    2017-04-01

    . Under rural land use, AMPA differences between seasons were found, being the highest concentration in spring (1.9 µg L-1). In groundwater glyphosate and AMPA concentrations were detected in 32 and 36% of the analyzed samples respectively. Medium and maximum glyphosate and AMPA concentrations were 0.7 and 1.0 µg L-1, and 2.3 and 6.0 µg L-1, respectively. In the first sampling date, glyphosate and AMPA were not detected probably associated with a dilution during a period of high groundwater recharge. On the contrary, in the second date the two molecules were detected in coincidence with a previous period with lowering water table accompanied by the first recharges. The temporal dynamics showed that herbicides are found in higher concentrations in surface water during the spring, and this is possibly associated with overlapping applications with rains that produce runoff. In groundwater, detections were associated with periods where the first small recharges are produced, which are concentrated in solutes. Loss of the environmental services retention and degradation of glyphosate of the agricultural soils was confirmed

  2. Characterization of glyphosate resistance in cloned Amaranthus palmeri plants

    Science.gov (United States)

    Glyphosate resistant Palmer amaranth from Georgia (GA) possesses multiple copies of the target site, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) of this herbicide. Cloned plants of glyphosate-resistant Palmer amaranth biotypes from Mississippi (MS) were compared with GA populations using le...

  3. Transcriptome response to glyphosate in sensitive and resistant soybean

    Science.gov (United States)

    The majority of soybeans planted in the United States are resistant to glyphosate due to introduction of a gene encoding for a glyphosate-insensitive 5-enolypyruvylshikimate-3-phosphate synthase (EPSPS). Gene expression profiling was conducted using cDNA microarrays to address questions related to p...

  4. Hormesis with glyphosate depends on coffee growth stage

    Science.gov (United States)

    Weed management systems in almost all Brazilian coffee plantations allow herbicide spray to drift on crop plants. In order to evaluate if there is any effect of the most commonly used herbicide in coffee production, glyphosate, on coffee plants, a range of glyphosate doses were applied directly on ...

  5. Assessing the Value of Glyphosate in the South African Agricultural Sector

    OpenAIRE

    Gouse, Marnus

    2014-01-01

    This study assessed the value of glyphosate in the South African agricultural sector with focus on the 2012/13 agricultural season. Glyphosate is the most used herbicide in South African and in 2012 more than 23 million litres of glyphosate was sold at an estimated value of R641 million. Glyphosate is a highly effective broad spectrum herbicide and the only herbicide on the market with a systemic mode of action. Glyphosate is considered to be, based on numerous scientific studies environmenta...

  6. Assessing the spatial distribution of glyphosate-AMPA in an Argentinian farm field using a pedometric technique

    Science.gov (United States)

    Barbera, Agustin; Zamora, Martin; Domenech, Marisa; Vega-Becerra, Andres; Castro-Franco, Mauricio

    2017-04-01

    The cultivation of transgenic glyphosate-resistant crops has been the most rapidly adopted crop technology in Argentina since 1997. Thus, more than 180 million liters of the broad-spectrum herbicide glyphosate (N - phosphonomethylglicine) are applied every year. The intensive use of glyphosate combined with geomorphometrical characteristics of the Pampa region is a matter of environmental concern. An integral component of assessing the risk of soil contamination in farm fields is to describe the spatial distribution of the levels of contaminant agent. Application of pedometric techniques for this purpose has been scarcely demonstrated. These techniques could provide an estimate of the concentration at a given unsampled location, as well as the probability that concentration will exceed the critical threshold concentration. In this work, a pedometric technique for assessing the spatial distribution of glyphosate in farm fields was developed. A field located at INTA Barrow, Argentina (Lat: -38.322844, Lon: -60.25572) which has a great soil spatial variability, was divided by soil-specific zones using a pedometric technique. This was developed integrating INTA Soil Survey information and a digital elevation model (DEM) obtained from a DGPS. Firstly, 10 topographic indices derived from a DEM were computed in a Random Forest algorithm to obtain a classification model for soil map units (SMU). Secondly, a classification model was applied to those topographic indices but at a scale higher than 1:1000. Finally, a spatial principal component analysis and a clustering using Fuzzy K-means were used into each SMU. From this clustering, three soil-specific zones were determined which were also validated through apparent electrical conductivity (CEa) measurements. Three soil sample points were determined by zone. In each one, samples from 0-10, 10-20 and 20-40cm depth were taken. Glyphosate content and AMPA in each soil sample were analyzed using de UPLC-MS/MS ESI (+/-). Only

  7. Spray droplet size, drift potential, and risks to nontarget organisms from aerially applied glyphosate for coca control in Colombia.

    Science.gov (United States)

    Hewitt, Andrew J; Solomon, Keith R; Marshall, E J P

    2009-01-01

    A wind tunnel atomization study was conducted to measure the emission droplet size spectra for water and Glyphos (a glyphosate formulation sold in Colombia) + Cosmo-flux sprays for aerial application to control coca and poppy crops in Colombia. The droplet size spectra were measured in a wind tunnel for an Accu-Flo nozzle (with 16 size 0.085 [2.16 mm] orifices), under appropriate simulated aircraft speeds (up to 333 km/h), using a laser diffraction instrument covering a dynamic size range for droplets of 0.5 to 3,500 microm. The spray drift potential of the glyphosate was modeled using the AGDISP spray application and drift model, using input parameters representative of those occurring in Colombia for typical aerial application operations. The droplet size spectra for tank mixes containing glyphosate and Cosmo-Flux were considerably finer than water and became finer with higher aircraft speeds. The tank mix with 44% glyphosate had a D(v0.5) of 128 microm, while the value at the 4.9% glyphosate rate was 140 microm. These are classified as very fine to fine sprays. Despite being relatively fine, modeling showed that the droplets would not evaporate as rapidly as most similarly sized agricultural sprays because the nonvolatile proportion of the tank mix (active and inert adjuvant ingredients) was large. Thus, longer range drift is small and most drift that does occur will deposit relatively close to the application area. Drift will only occur downwind and, with winds of velocity less than the modeled maximum of 9 km/h, the drift distance would be substantially reduced. Spray drift potential might be additionally reduced through various practices such as the selection of nozzles, tank mix adjuvants, aircraft speeds, and spray pressures that would produce coarser sprays. Species sensitivity distributions to glyphosate were constructed for plants and amphibians. Based on modeled drift and 5th centile concentrations, appropriate no-spray buffer zones (distance from the

  8. Evaluation of two methods to determine glyphosate and AMPA in soils of Argentina

    Science.gov (United States)

    De Geronimo, Eduardo; Lorenzon, Claudio; Iwasita, Barbara; Faggioli, Valeria; Aparicio, Virginia; Costa, Jose Luis

    2017-04-01

    Argentine agricultural production is fundamentally based on a technological package combining no-tillage and the dependence of glyphosate applications to control weeds in transgenic crops (soybean, maize and cotton). Therefore, glyphosate is the most employed herbicide in the country, where 180 to 200 million liters are applied every year. Due to its widespread use, it is important to assess its impact on the environment and, therefore, reliable analytical methods are mandatory. Glyphosate molecule exhibits unique physical and chemical characteristics which difficult its quantification, especially in soils with high organic matter content, such as the central eastern Argentine soils, where strong interferences are normally observed. The objective of this work was to compare two methods for extraction and quantification of glyphosate and AMPA in samples of 8 representative soils of Argentina. The first analytical method (method 1) was based on the use of phosphate buffer as extracting solution and dichloromethane to minimize matrix organic content. In the second method (method 2), potassium hydroxide was used to extract the analytes followed by a clean-up step using solid phase extraction (SPE) to minimize strong interferences. Sensitivity, recoveries, matrix effects and robustness were evaluated. Both methodologies involved a derivatization with 9-fluorenyl-methyl-chloroformate (FMOC) in borate buffer and detection based on ultra-high-pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Recoveries obtained from soil samples spiked at 0.1 and 1 mg kg-1 and were satisfactory in both methods (70% - 120%). However, there was a remarkable difference regarding the matrix effect, being the SPE clean-up step (method 2) insufficient to remove the interferences. Whereas the dilution and the clean-up with dichloromethane (method 1) were more effective minimizing the ionic suppression. Moreover, method 1 had fewer steps in the protocol of sample

  9. Mode of action of glyphosate in Candida maltosa.

    Science.gov (United States)

    Bode, R; Melo, C; Birnbaum, D

    1984-11-01

    The broad-spectrum herbicide glyphosate inhibits the growth of Candida maltosa and causes the accumulation of shikimic acid and shikimate-3-phosphate. Glyphosate is a potent inhibitor of three enzymes of aromatic amino acid biosynthesis in this yeast. In relation to tyrosine-sensitive 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase and dehydroquinate synthase, the inhibitory effect appears at concentrations in the mM range, but 5-enolpyruvylshikimate 3-phosphate (EPSP) synthase is inhibited by micromolar concentrations of glyphosate. Inhibition of partially purified EPSP synthase reaction by glyphosate is competitive with respect to phosphoenolpyruvate (PEP) with a Ki-value of 12 microM. The app. Km for PEP is about 5-fold higher and was 62 microM. Furthermore, the presence of glyphosate leads to derepression of many amino acid biosynthetic enzymes.

  10. Effect of different doses of glyphosate in soybean

    Directory of Open Access Journals (Sweden)

    S. A. Gomes

    2013-07-01

    Full Text Available Abstract: Brazil ranks second in production of conventional soybeans and third in production of transgenic soybeans. The main advantage of transgenic soybean is resistant to the herbicide glyphosate, but the continued use of exaggeration and even of the same herbicide on soybean can significantly decrease acquired resistance. This work aimed to evaluate the effects of different doses of glyphosate can result in soybean. The experiment was conducted in a greenhouse on the Campus of UFMT in Sinop-MT, and evaluated five doses of glyphosate in transgenic soybeans intercropped with two conventional soybeans. The characters were evaluated for phytotoxicity scores and length of the root system. It was found that, regardless of the amount of glyphosate applied occur symptoms of phytotoxicity in conventional and transgenic soybean. Whereas the most damage will be in conventional soybean, and transgenic soybean little affected by the action of the herbicide.Key words: Glycine max, glyphosate, phytotoxicity

  11. Identification of Glyphosate Resistance in Lolium rigidum Gaudin

    Directory of Open Access Journals (Sweden)

    Danijela Pavlović

    2011-01-01

    Full Text Available Glyphosate resistance was found in Lolium rigidum Gaudin (Rigid ryegrass, LOLRI inSouth Africa. Suspected glyphosate-resistant L. rigidum populations were collected andgrown under greenhouse conditions. The plants were sprayed with a range of doses of glyphosate35 days after planting and shoot dry biomass was determined 17 days after herbicidetreatment. Based on the dose-response experiment conducted in the greenhouse,one population of L. rigidum suspected to be resistant to glyphosate was approximately 5.3fold more resistant than susceptible population. The other population was 2.8 fold moreresistant than susceptible population. Difference between the two suspected resistant populationswas 1.9 fold. All plants were treated with glyphosate (1000 g a.i. ha-1 and shikimicacid was extracted 2, 4 and 6 days after treatment. The plants of susceptible populationsaccumulated more shikimic acid than other two populations.

  12. Refractory cardiopulmonary failure after glyphosate surfactant intoxication: a case report

    Directory of Open Access Journals (Sweden)

    Chang Chia-Chu

    2009-01-01

    Full Text Available Abstract Background Glyphosate is an herbicide considered to be of low toxicity to humans because its effects are specific to plants. However, fatal reactions to glyphosate have been reported after the ingestion of large amounts. Pulmonary edema, shock, and arrhythmia were the reported causes of mortality. Case presentation We present the case of a 57-year-old woman who was admitted to the emergency department unconsciousness after ingestion of glyphosate surfactant in a suicide attempt. Metabolic acidosis, refractory respiratory failure, and shock developed during hospitalization. Despite aggressive supportive care, the patient died in the hospital. Conclusion The toxicokinetics of glyphosate surfactant is complicated. Respiratory failure, metabolic acidosis, tachycardia, elevated creatinine, and hyperkalemia are poor prognostic factors if presented. Physicians should consider using hemodialysis early to improve the outcome of patients with glyphosate surfactant intoxication.

  13. 草甘膦毒性研究进展%Research advance in ecotoxicity of glyphosate

    Institute of Scientific and Technical Information of China (English)

    周垂帆; 李莹; 张晓勇; 俞元春

    2013-01-01

    随着现代农业的飞速发展,农药的应用越来越广泛。而目前草甘膦是使用最广泛、用量最大的除草剂种类之一,其在环境中的大量残留给环境带来了巨大潜在风险。介绍了草甘膦对靶标生物(植物)的制毒机理和非靶标生物(如:水生生物、两栖类动物、土壤生物和哺乳动物)的生态毒性,总结了草甘膦在群落、个体、细胞和分子水平上的生态毒性。综合国内外最新的研究表明:草甘膦制剂具有低毒性,且毒性要远远高于草甘膦酸的毒性,农药草甘膦制剂对非光合生物产生毒性的原因主要是由于表面活性剂的存在。而大多研究都表明,不同的草甘膦制剂及其组成成分毒性强弱为表面活性剂>草甘膦制剂>草甘膦酸>草甘膦异丙胺盐,而草甘膦酸产生的毒性原因主要和其产生的酸性物质有关,并认为在当前的使用品种和剂量的状况下,草甘膦对人类的危害风险是很低的。最后,分析了草甘膦在土壤中与无机重金属共存的的生态毒性研究现状,认为由于草甘膦分子结构中含有磷酸基、羧基、氨基等配位基团,能够与土壤或水体中金属离子发生络合反应,使得重金属在一定程度上能够降低草甘膦的除草效率,草甘膦一定程度上也能够降低重金属对生物的毒性和有效性,此外对今后的研究重点进行了展望。%It has been widely recognized that pesticides represent a potential threat in aquatic and soil ecosystems. Glyphosate is a kind of antibiotics which has been extensively used in most countries. Its residues in environment bring to a potential hazard. However, the knowledge on the toxicity of pesticides to organism is still limited. The present work attempts to provide a summary of the utility and the environmental health problems of glyphosate applications. It comes in a number of chemical forms but most of the formulated

  14. Quantitative patch and repeated open application testing in methyldibromo glutaronitrile-sensitive patients.

    Science.gov (United States)

    Schnuch, A; Kelterer, D; Bauer, A; Schuster, Ch; Aberer, W; Mahler, V; Katzer, K; Rakoski, J; Jappe, U; Krautheim, A; Bircher, A; Koch, P; Worm, M; Löffler, H; Hillen, U; Frosch, P J; Uter, W

    2005-04-01

    Contact allergy to methyldibromo glutaronitrile (MDBGN), often combined with phenoxyethanol (PE) (e.g., Euxyl K 400), increased throughout the 1990s in Europe. Consequently, in 2003, the European Commission banned its use in leave-on products, where its use concentration was considered too high and the non-sensitizing use concentration as yet unknown. The 2 objectives of the study are (a) to find a maximum non-eliciting concentration in a leave-on product in MDBGN/PE-sensitized patients, which could possibly also be considered safe regarding induction and (b) to find the best patch test concentration for MDBGN. We, therefore, performed a use-related test (ROAT) in patients sensitized to MDBGN/PE (n = 39) with 3 concentrations of MDBGN/PE (50, 100 and 250 p.p.m. MDBGN, respectively). A subset of these patients (n = 24) was later patch-tested with various concentrations (0.1, 0.2, 0.3 and 0.5% MDBGN, respectively). 15 patients (38%, 95% confidence interval (CI) = 23-55%) had a negative and 24 (62%; 95% CI = 45-77%) a positive overall repeated open application test (ROAT) result. 13 reacted to the lowest (50 p.p.m.), 8 to the middle (100 p.p.m.) and 3 to the highest concentration (250 p.p.m.) only. In those 13 reacting to the lowest ROAT concentration, dermatitis developed within a few days (1-7). The strength of the initial and the confirmatory patch test result, respectively, and the outcome of the ROAT were positively associated. Of the 24 patients with a use and confirmatory patch test, 15 reacted to 0.1% MDBGN, 16 to 0.2%, 17 to 0.3% and 22 to 0.5%. With the patch test concentration of 0.5%, the number of ROAT-negative patients but patch-test-positive patients increases considerably, particularly due to + reactions. A maximum sensitivity of 94% (95% CI = 70-100%) is reached with a patch test concentration of 0.2%, and is not further improved by increasing the concentration. However, the specificity decreases dramatically from 88 (95% CI = 47-100%) with 0.2% to a

  15. Lack of transgene and glyphosate effects on yield, and mineral and amino acid content of glyphosate-resistant soybean.

    Science.gov (United States)

    Duke, Stephen O; Rimando, Agnes M; Reddy, Krishna N; Cizdziel, James V; Bellaloui, Nacer; Shaw, David R; Williams, Martin M; Maul, Jude E

    2017-05-25

    There has been controversy as to whether the glyphosate resistance gene and/or glyphosate applied to glyphosate-resistant (GR) soybean affect the content of cationic minerals (especially Mg, Mn and Fe), yield and amino acid content of GR soybean. A two-year field study (2013 and 2014) examined these questions at sites in Mississippi, USA. There were no effects of glyphosate, the GR transgene or field crop history (for a field with both no history of glyphosate use versus one with a long history of glyphosate use) on grain yield. Furthermore, these factors had no consistent effects on measured mineral (Al, As, Ba, Cd, Ca, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Ni, Pb, Rb, Se, Sr, Tl, U, V, Zn) content of leaves or harvested seed. Effects on minerals were small and inconsistent between years, treatments and mineral, and appeared to be random false positives. No notable effects on free or protein amino acids of the seed were measured, although glyphosate and its degradation product, aminomethylphosphonic acid (AMPA), were found in the seed in concentrations consistent with previous studies. Neither glyphosate nor the GR transgene affect the content of the minerals measured in leaves and seed, harvested seed amino acid composition, or yield of GR soybean. Furthermore, soils with a legacy of GR crops have no effects on these parameters in soybean. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  16. Genotoxicity Expert Panel review: weight of evidence evaluation of the genotoxicity of glyphosate, glyphosate-based formulations, and aminomethylphosphonic acid.

    Science.gov (United States)

    Brusick, David; Aardema, Marilyn; Kier, Larry; Kirkland, David; Williams, Gary

    2016-09-01

    In 2015, the International Agency for Research on Cancer (IARC) published a monograph concluding there was strong evidence for genotoxicity of glyphosate and glyphosate formulations and moderate evidence for genotoxicity of the metabolite aminomethylphosphonic acid (AMPA). These conclusions contradicted earlier extensive reviews supporting the lack of genotoxicity of glyphosate and glyphosate formulations. The IARC Monograph concluded there was strong evidence of induction of oxidative stress by glyphosate, glyphosate formulations, and AMPA. The Expert Panel reviewed the genotoxicity and oxidative stress data considered in the IARC Monograph, together with other available data not considered by IARC. The Expert Panel defined and used a weight of evidence (WoE) approach that included ranking of studies and endpoints by the strength of their linkage to events associated with carcinogenic mechanisms. Importantly, the Expert Panel concluded that there was sufficient information available from a very large number of regulatory genotoxicity studies that should have been considered by IARC. The WoE approach, the inclusion of all relevant regulatory studies, and some differences in interpretation of individual studies led to significantly different conclusions by the Expert Panel compared with the IARC Monograph. The Expert Panel concluded that glyphosate, glyphosate formulations, and AMPA do not pose a genotoxic hazard and the data do not support the IARC Monograph genotoxicity evaluation. With respect to carcinogenicity classification and mechanism, the Expert Panel concluded that evidence relating to an oxidative stress mechanism of carcinogenicity was largely unconvincing and that the data profiles were not consistent with the characteristics of genotoxic carcinogens.

  17. Repeatability in computer-aided diagnosis: Application to breast cancer diagnosis on sonography.

    Science.gov (United States)

    Drukker, Karen; Pesce, Lorenzo; Giger, Maryellen

    2010-06-01

    The aim of this study was to investigate the concept of repeatability in a case-based performance evaluation of two classifiers commonly used in computer-aided diagnosis in the task of distinguishing benign from malignant lesions. The authors performed .632+ bootstrap analyses using a data set of 1251 sonographic lesions of which 212 were malignant. Several analyses were performed investigating the impact of sample size and number of bootstrap iterations. The classifiers investigated were a Bayesian neural net (BNN) with five hidden units and linear discriminant analysis (LDA). Both used the same four input lesion features. While the authors did evaluate classifier performance using receiver operating characteristic (ROC) analysis, the main focus was to investigate case-based performance based on the classifier output for individual cases, i.e., the classifier outputs for each test case measured over the bootstrap iterations. In this case-based analysis, the authors examined the classifier output variability and linked it to the concept of repeatability. Repeatability was assessed on the level of individual cases, overall for all cases in the data set, and regarding its dependence on the case-based classifier output. The impact of repeatability was studied when aiming to operate at a constant sensitivity or specificity and when aiming to operate at a constant threshold value for the classifier output. The BNN slightly outperformed the LDA with an area under the ROC curve of 0.88 versus 0.85 (p90%) and low specificity (clinical decision making. © 2010 American Association of Physicists in Medicine.

  18. Semiparametric Methods to Contrast Gap Time Survival Functions: Application to Repeat Kidney Transplantation

    OpenAIRE

    Shu, Xu; Schaubel, Douglas E.

    2015-01-01

    Times between successive events (i.e., gap times) are of great importance in survival analysis. Although many methods exist for estimating covariate effects on gap times, very few existing methods allow for comparisons between gap times themselves. Motivated by the comparison of primary and repeat transplantation, our interest is specifically in contrasting the gap time survival functions and their integration (restricted mean gap time). Two major challenges in gap time analysis are non-ident...

  19. Repeated applications of cold atmospheric pressure plasma does not induce resistance in Staphylococcus aureus embedded in biofilms

    Directory of Open Access Journals (Sweden)

    Matthes, Rutger

    2014-09-01

    Full Text Available [english] Introduction: The increasing microbial resistance against antibiotics complicates the therapy of bacterial infections. Therefore new therapeutic options, particularly those causing no resistance, are of high interest. Cold atmospheric plasma is one possible option to eradicate multidrug resistant microorganisms, and so far no resistance development against physical plasma is known.Method: We tested 6-fold repeated plasma applications on a strain embedded in biofilm and compared the reduction of the colony forming units between the different treatment periods to asses a possible development of resistance.Result: For all treatment periods, the control biofilms were reduced by plasma in average by 1.7 log CFU, and decreased from 7.6 to 5.8 log (CFU/cm within 5 hours. The results demonstrated that repeated plasma doses not induce resistance or habituation against plasma applied within short time periods.Conclusion: The repeated application of cold plasma is a promising option for the treatment of infected wounds without the risk of development of resistance against plasma.

  20. Resistência ao glyphosate em biótipos de buva (Conyza spp. das regiões oeste e sudoeste do Paraná Resistance to glyphosate in Conyza spp. biotypes in western and southwestern Parana, Brazil

    Directory of Open Access Journals (Sweden)

    M.M Trezzi

    2011-01-01

    and southwestern Parana, comparing them with susceptible biotypes. The experimental design was completely randomized in a factorial 12 x 8 x 3. The factors consisted of twelve biotypes of horseweed, eight glyphosate doses (0, 100, 180, 324, 583, 1.050, 1.888, and 3.345 g ha-1 and three evaluation periods for the control (7, 14 and 21 days after application. For the fresh and dry matter variables, the factorial design used was 12 x 8. The variables evaluated were visual inspection, fresh and dry matter, C50, GR50 and resistance factor. The dose of 3.345 g glyphosate ha-1 presented the highest control levels of all biotypes, but the control of the suspected biotypes was not effective, requiring higher doses. All the horseweed biotypes suspected of resistancetoglyphosatehaveconfirmedthisfeature.However,awiderangeofresistancefactorswas verified, characterizing the variability among the resistant biotypes. This information may be used for planning management strategies of resistant populations, as well as in preventing the occurrence of new areas infested with glyphosate-resistant horseweed.

  1. Efeito da deriva simulada de glyphosate no crescimento inicial de plantas de pinhão-manso Effect of simulated glyphosate drift on the initial growth of physic nut plants

    Directory of Open Access Journals (Sweden)

    N.V Costa

    2009-12-01

    showed reductions after glyphosate drift simulation, compared with the control. Thus, it can be concluded that the initial growth of the physic nut plants was influenced by simulated glyphosate drift, and that the drift of rates higher than 45.0 g ha-1 can cause severe damage to the plants during the period of 41 days after application.

  2. Low doses of glyphosate change the response of soybean to later glyphosate exposures

    Science.gov (United States)

    The stimulatory effect of low doses of toxic substances is known as hormesis. Many herbicides that cause severe injury to plants at recommended rates, promote growth or have other stimulatory effects at very low doses. The objective of this study was to evaluate glyphosate-induced hormesis in soyb...

  3. Manejo de Conyza bonariensis resistente ao herbicida glyphosate Management of Glyphosate-resistant Conyza bonariensis

    National Research Council Canada - National Science Library

    J.M. Paula; L. Vargas; D. Agostinetto; M.A. Nohatto

    2011-01-01

    ... distribuída no Brasil, com presença marcante nos Estados do Rio Grande do Sul e do Paraná. Biótipos de C. bonariensis resistentes ao glyphosate foram identificados nos Estados do Rio Grande do Sul...

  4. 转基因抗草甘膦作物的新发展%The New Development of Transgenic-resistant Glyphosate Crops

    Institute of Scientific and Technical Information of China (English)

    苏少泉

    2012-01-01

    Glyphosate is the most widely used herbicide in the world after adoption of glyphosate-tolerant crops were accepted, new and improved glphosate-tolerant crops continue to be rapidly developed. These crops showed great crop safety to multiple glyphosate application, higher rates and wider application timings. This papers reviews the current development, varieties improvent, multiple resistance of glyphosate-tolerant crops, as well as formulation and combination of glyphosate.%在接受抗草甘膦作物后,草甘膦成为世界应用最广泛的除草剂,新的与改进的抗草甘膦作物继续迅速发展,草甘膦多次处理、较高剂量以及较宽的喷药时间对此类作物具有较高的安全性.评述了草甘膦抗性作物最近的发展,抗性品种的改进、多抗性以及草甘膦剂型与混用.

  5. Multiple resistance to glyphosate and pyrithiobac in Palmer amaranth (Amaranthus palmeri) from Mississippi and response to flumiclorac

    Science.gov (United States)

    Greenhouse and laboratory studies were conducted to confirm and quantify glyphosate resistance, to investigate interactions between flumiclorac and glyphosate mixtures on weed control, to determine patterns of absorption and translocation of glyphosate applied alone and in combination with flumiclor...

  6. A novel 5-enolpyruvylshikimate-3-phosphate synthase shows high glyphosate tolerance in Escherichia coli and tobacco plants

    National Research Council Canada - National Science Library

    Cao, Gaoyi; Liu, Yunjun; Zhang, Shengxue; Yang, Xuewen; Chen, Rongrong; Zhang, Yuwen; Lu, Wei; Liu, Yan; Wang, Jianhua; Lin, Min; Wang, Guoying

    2012-01-01

    ...) is the primary target of the broad-spectrum herbicide glyphosate. Identification of new aroA genes coding for EPSPS with a high level of glyphosate tolerance is essential for the development of glyphosate-tolerant crops...

  7. 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

  8. Application of inter simple sequence repeat (ISSR) markers to plant genetics.

    Science.gov (United States)

    Godwin, I D; Aitken, E A; Smith, L W

    1997-08-01

    Microsatellites or simple sequence repeats (SSRs) are ubiquitous in eukaryotic genomes. Single-locus SSR markers have been developed for a number of species, although there is a major bottleneck in developing SSR markers whereby flanking sequences must be known to design 5'-anchors for polymerase chain reaction (PCR) primers. Inter SSR (ISSR) fingerprinting was developed such that no sequence knowledge was required. Primers based on a repeat sequence, such as (CA)n, can be made with a degenerate 3'-anchor, such as (CA)8RG or (AGC)6TY. The resultant PCR reaction amplifies the sequence between two SSRs, yielding a multilocus marker system useful for fingerprinting, diversity analysis and genome mapping. PCR products are radiolabelled with 32P or 33P via end-labelling or PCR incorporation, and separated on a polyacrylamide sequencing gel prior to autoradiographic visualisation. A typical reaction yields 20-100 bands per lane depending on the species and primer. We have used ISSR fingerprinting in a number of plant species, and report here some results on two important tropical species, sorghum and banana. Previous investigators have demonstrated that ISSR analysis usually detects a higher level of polymorphism than that detected with restriction fragment length polymorphism (RFLP) or random amplified polymorphic DNA (RAPD) analyses. Our data indicate that this is not a result of greater polymorphism genetically, but rather technical reasons related to the detection methodology used for ISSR analysis.

  9. Semiparametric methods to contrast gap time survival functions: Application to repeat kidney transplantation.

    Science.gov (United States)

    Shu, Xu; Schaubel, Douglas E

    2016-06-01

    Times between successive events (i.e., gap times) are of great importance in survival analysis. Although many methods exist for estimating covariate effects on gap times, very few existing methods allow for comparisons between gap times themselves. Motivated by the comparison of primary and repeat transplantation, our interest is specifically in contrasting the gap time survival functions and their integration (restricted mean gap time). Two major challenges in gap time analysis are non-identifiability of the marginal distributions and the existence of dependent censoring (for all but the first gap time). We use Cox regression to estimate the (conditional) survival distributions of each gap time (given the previous gap times). Combining fitted survival functions based on those models, along with multiple imputation applied to censored gap times, we then contrast the first and second gap times with respect to average survival and restricted mean lifetime. Large-sample properties are derived, with simulation studies carried out to evaluate finite-sample performance. We apply the proposed methods to kidney transplant data obtained from a national organ transplant registry. Mean 10-year graft survival of the primary transplant is significantly greater than that of the repeat transplant, by 3.9 months (p=0.023), a result that may lack clinical importance.

  10. Variabilidade genética e sensibilidade de acessos de Pistia stratiotes ao herbicida glyphosate Genetic variability and sensitivity of Pistia stratiotes accesses to glyphosate

    Directory of Open Access Journals (Sweden)

    E.A.S. Cícero

    2007-09-01

    . Plant samples were collected in 12 water bodies in different regions in Brazil (Americana-AMC, Cambaratiba-CBT, Curitiba-CRB, Itapura-ITP, Jaboticabal-JBT, Lagoa Santa-LST, Piraí-PRI, Rio Grande-RGD, Rubinéia-RBN, Salto Grande-SGD, Santa Gertrudes-SGT and Três Lagoas-TLG. The accesses were characterized by the use of RAPD markers (Random Amplified Polymorphic DNA, whose unspecific starters allowed the analysis of polymorphic loci, which evidenced the distribution of the accesses into two groups, with high genetic similarity inside the sub-groups, but with high genetic divergence between them. The use of the RAPD technique evidenced the existence of genetic differences between the accesses. Plants growing in plastic pots (5 L were sprayed with glyphosate at the concentrations of 0.0, 0.6, 1.2, 1.8, 2.4 kg ha-1. Herbicide effects were evaluated on the 7th, 14th, and 21st days after application (DAA with control note attributions (0% without control and 100% leading to the complete death of the plants. No correspondence was observed between the structure of the access groups by the grouping multi-varied analysis using the RAPD technique and water lettuce susceptibility to glyphosate.

  11. Chemical evidence for the effect of Urochloa ruziziensis on glyphosate-resistant soybeans.

    Science.gov (United States)

    Nepomuceno, Mariluce; Chinchilla, Nuria; Varela, Rosa M; Molinillo, José Mg; Lacret, Rodney; Alves, Pedro Lca; Macias, Francisco A

    2017-10-01

    Soybean (Glycine max) is an important oleaginous legume that has been cultivated in new areas in Brazil, including pastures. Problems of reduced production yields have been reported by soybean growers when the crop is sown immediately after desiccation of pastures of Urochloa spp. using glyphosate. The objective of this work was to extract, isolate and identify the major chemicals from U. ruziziensis that have phytotoxic activity and to evaluate the possible relation between this effect and reduced soybean yield. U. ruziziensis plants at the flowering stage were desiccated using glyphosate at 1.44 kg ha(-1) . The plants were collected between five and ten days after treatment. Extracts of dried and ground shoots were obtained by sequential extraction with hexane, dichloromethane and methanol. The results of wheat coleoptile bioassays indicated that the methanol extract was more inhibitory than the dichloromethane extract regardless of glyphosate application. Protodioscin, a steroidal saponin, was isolated from the extract as the major component and the activities of this compound were in good agreement with those found for the extract. The release of this compound into the soil is a plausible explanation for the decrease in production observed in transgenic soybean crop after desiccation of U. ruziziensis. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Uptake, Translocation, Metabolism, and Distribution of Glyphosate in Nontarget Tea Plant (Camellia sinensis L.).

    Science.gov (United States)

    Tong, Mengmeng; Gao, Wanjun; Jiao, Weiting; Zhou, Jie; Li, Yeyun; He, Lili; Hou, Ruyan

    2017-09-06

    The uptake, translocation, metabolism, and distribution behavior of glyphosate in nontarget tea plant were investigated. The negative effects appeared to grown tea saplings when the nutrient solution contained glyphosate above 200 mg L(-1). Glyphosate was highest in the roots of the tea plant, where it was also metabolized to aminomethyl phosphonic acid (AMPA). The glyphosate and AMPA in the roots were transported through the xylem or phloem to the stems and leaves. The amount of AMPA in the entire tea plant was less than 6.0% of the amount of glyphosate. The glyphosate level in fresh tea shoots was less than that in mature leaves at each day. These results indicated that free glyphosate in the soil can be continuously absorbed by, metabolized in, and transported from the roots of the tea tree into edible leaves, and therefore, free glyphosate residues in the soil should be controlled to produce teas free of glyphosate.

  13. Glyphosate in Runoff Waters and in the Root-Zone: A Review

    Directory of Open Access Journals (Sweden)

    Lyndsay E. Saunders

    2015-11-01

    Full Text Available Glyphosate is the most commonly-used herbicide in the world. The present review summarizes the discovery, prevalence, chemical and physical properties, mode of action and effects in plants, glyphosate resistance and the environmental fate of glyphosate. Numerous studies are reviewed that demonstrate that glyphosate may run off of fields where it is applied, while other studies provide evidence that plant roots can take up glyphosate. Non-target vegetation may be exposed to glyphosate in the root-zone, where it has the potential to remove aqueous glyphosate from the system. Further study on the effects of root-zone glyphosate on non-target vegetation is required to develop best management practices for land managers seeking to ameliorate the effects of root-zone glyphosate exposure.

  14. Glyphosate effects on the gene expression of the apical bud in soybean (Glycine max).

    Science.gov (United States)

    Jiang, Ling-Xue; Jin, Long-Guo; Guo, Yong; Tao, Bo; Qiu, Li-Juan

    2013-08-09

    Glyphosate is a broad spectrum, non-selective herbicide which has been widely used for weed control. Much work has focused on elucidating the high accumulation of glyphosate in shoot apical bud (shoot apex). However, to date little is known about the molecular mechanisms of the sensitivity of shoot apical bud to glyphosate. Global gene expression profiling of the soybean apical bud response to glyphosate treatment was performed in this study. The results revealed that the glyphosate inhibited tryptophan biosynthesis of the shikimic acid pathway in the soybean apical bud, which was the target site of glyphosate. Glyphosate inhibited the expression of most of the target herbicide site genes. The promoter sequence analysis of key target genes revealed that light responsive elements were important regulators in glyphosate induction. These results will facilitate further studies of cloning genes and molecular mechanisms of glyphosate on soybean shoot apical bud. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. What have the mechanisms of resistance to glyphosate taught us?

    Science.gov (United States)

    Shaner, Dale L; Lindenmeyer, Richard Bradley; Ostlie, Michael H

    2012-01-01

    The intensive use of glyphosate alone to manage weeds has selected populations that are glyphosate resistant. The three mechanisms of glyphosate resistance that have been elucidated are (1) target-site mutations, (2) gene amplification and (3) altered translocation due to sequestration. What have we learned from the selection of these mechanisms, and how can we apply those lessons to future herbicide-resistant crops and new mechanisms of action? First, the diversity of glyphosate resistance mechanisms has helped further our understanding of the mechanism of action of glyphosate and advanced our knowledge of plant physiology. Second, the relatively rapid evolution of glyphosate-resistant weed populations provides further evidence that no herbicide is invulnerable to resistance. Third, as new herbicide-resistant crops are developed and new mechanisms of action are discovered, the weed science community needs to ensure that we apply the lessons we have learned on resistance management from the experience with glyphosate. Every new weed management system must be evaluated during development for its potential to select for resistance, and stewardship programs should be in place when the new program is introduced.

  16. Lack of glyphosate resistance gene transfer from Roundup Ready soybean to Bradyrhizobium japonicum under field and laboratory conditions.

    Science.gov (United States)

    Isaza, Laura Arango; Opelt, Katja; Wagner, Tobias; Mattes, Elke; Bieber, Evi; Hatley, Elwood O; Roth, Greg; Sanjuán, Juan; Fischer, Hans-Martin; Sandermann, Heinrich; Hartmann, Anton; Ernst, Dieter

    2011-01-01

    A field study was conducted at the Russell E. Larson Agricultural Research Center to determine the effect of transgenic glyphosate-resistant soybean in combination with herbicide (Roundup) application on its endosymbiont Bradyrhizobium japonicum. DNA of bacteroids from isolated nodules was analysed for the presence of the transgenic 5-enolpyruvylshikimate-3-phosphate synthase (CP4-EPSPS) DNA sequence using polymerase chain reaction (PCR). To further assess the likelihood that the EPSPS gene may be transferred from the Roundup Ready (RR) soybean to B. japonicum, we have examined the natural transformation efficiency of B. japonicum strain 110spc4. Analyses of nodules showed the presence of the transgenic EPSPS DNA sequence. In bacteroids that were isolated from nodules of transgenic soybean plants and then cultivated in the presence of glyphosate this sequence could not be detected. This indicates that no stable horizontal gene transfer (HGT) of the EPSPS gene had occurred under field conditions. Under laboratory conditions, no natural transformation was detected in B. japonicum strain 110spc4 in the presence of various amounts of recombinant plasmid DNA. Our results indicate that no natural competence state exists in B. japonicum 110spc4. Results from field and laboratory studies indicate the lack of functional transfer of the CP4-EPSPS gene from glyphosate-tolerant soybean treated with glyphosate to root-associated B. japonicum.

  17. Determination of Glyphosate Levels in Breast Milk Samples from Germany by LC-MS/MS and GC-MS/MS.

    Science.gov (United States)

    Steinborn, Angelika; Alder, Lutz; Michalski, Britta; Zomer, Paul; Bendig, Paul; Martinez, Sandra Aleson; Mol, Hans G J; Class, Thomas J; Pinheiro, Nathalie Costa

    2016-02-17

    This study describes the validation and application of two independent analytical methods for the determination of glyphosate in breast milk. They are based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively. For LC-MS/MS, sample preparation involved an ultrafiltration followed by chromatography on an anion exchange column. The analysis by GC-MS/MS involved an extraction step, cleanup on a cation exchange column, and derivatization with heptafluorobutanol and trifluoroacetic acid anhydride. Both methods were newly developed for breast milk and are able to quantify glyphosate residues at concentrations as low as 1 ng/mL. The methods were applied to quantify glyphosate levels in 114 breast milk samples, which had been collected from August to September of 2015 in Germany. The mothers participated at their own request and thus do not form a representative sample. In none of the investigated samples were glyphosate residues above the limit of detection found.

  18. EPSPS amplification in glyphosate-resistant spiny amaranth (Amaranthus spinosus): a case of gene transfer via interspecific hybridization from glyphosate-resistant Palmer amaranth (Amaranthus palmeri

    Science.gov (United States)

    Amaranthus spinosus, a common weed of pastures, is a close relative of Amaranthus palmeri, a problematic agricultural weed with widespread glyphosate resistance. These two species have been known to hybridize, allowing for transfer of glyphosate resistance. Glyphosate-resistant A. spinosus was rec...

  19. Glyphosate-resistant and glyphosate-susceptible Palmer amaranth (Amaranthus palmeri S Wats.): hyperspectral reflectance properties of plants and potential for classification

    Science.gov (United States)

    BACKGROUND: Palmer amaranth (Amaranthus palmeri S. Wats.) is a troublesome agronomic weed in the southern United States, and several populations have evolved resistance to glyphosate. This paper reports spectral signatures of glyphosate-resistant (GR) and glyphosate-sensitive (GS) plants, and explor...

  20. Glyphosate Use in Forest Plantations Uso de Glifosato en Plantaciones Forestales

    Directory of Open Access Journals (Sweden)

    Marcelo Kogan

    2010-12-01

    Full Text Available Under Chilean conditions the lack of weed control at forest tree establishment results in an average of at least 60% less biomass accumulation during the first year of growth of radiate pine or eucaliptus, and glyphosate offers a series of advantages in forestry weed management because its activity in both herbaceous weed groups, monocots and dicots, as well as annuals, biennials and perennials. Also, its efficacy in woody undesirable vegetation makes glyphosate a very important herbicide that can be applied to control herbaceous and woody weeds as pre-planting and during the second or third years of trees growth as strip applications. The aim of this review is to discuss the main uses of glyphosate in reforestation worldwide, during the first 2 yr after tree establishment, as broadcast application over the top of the forest trees and the most important factors that could affect glyphosate efficacy as a forest herbicide, like weed growth stage, application technique, volume and water quality, rainfastness, dew effect and the use of extra adjuvant with formulated glyphosate.Bajo las condiciones chilenas la falta de control de malezas al establecimiento de los árboles resulta en un promedio de al menos 60% menos acumulación de biomasa durante el primer año de crecimiento de pino radiata o eucalipto, y glifosato ofrece una serie de ventajas en el manejo de malezas forestales debido a su actividad en ambos grupos de malezas herbáceas, monocotiledóneas y dicotiledóneas, así como anuales, bianuales y perennes. Además, su eficacia en la vegetación leñosa indeseable hace al glifosato un herbicida muy importante que puede ser aplicado para controlar malezas herbáceas y leñosas en pre-plantación y durante el segundo o tercer año de crecimiento de los árboles como aplicaciones en franja. El objetivo de esta revisión es discutir los principales usos de glifosato en reforestación a lo largo del mundo, durante los primeros 2 años despu

  1. Evidence, Mechanism and Alternative Chemical Seedbank-Level Control of Glyphosate Resistance of a Rigid Ryegrass (Lolium rigidum) Biotype from Southern Spain.

    Science.gov (United States)

    Fernández-Moreno, Pablo T; Bastida, Fernando; De Prado, Rafael

    2017-01-01

    Rigid ryegrass (Lolium rigidum) is one of the most troublesome weeds in different crops in the Mediterranean region. A rigid ryegrass biotype from an olive grove in Jaén province (Andalusía, southern Spain), potentially resistant to glyphosate (RG), was tested for its resistance level through dose-response assays using a susceptible biotype (SG). To test the hypothesis of a non-target-site-based resistance, as point mutations are far less common mechanisms of glyphosate resistance, studies were also conducted to elucidate whether resistance was associated with biochemical, metabolism, molecular and/or physiological mechanisms. Alternative herbicide-based control options, including single-herbicide or herbicide mixtures with glyphosate, applied at seedling, tillering or full heading stages, were tested in field experiments for 2 years for their efficacy against rigid ryegrass plants and their effects on the soil seed bank. Resistance levels of the RG biotype were 23- (LD50) and 7-fold (GR50) higher compared to the SG biotype. The SG biotype exhibited a significantly greater shikimic acid accumulation than the RG one. At 96 HAT, 58 and 89% of applied (14)C-glyphosate was up taken by leaves of RG and SG biotype plants, respectively, and, at this time, a significantly higher proportion of the glyphosate taken up by the treated leaf remained in its tissue in RG plants compared to the SG ones. The RG biotype did not reveal any point mutation in the glyphosate target site EPSP synthase. Overall, results confirmed reduced glyphosate uptake and translocation as being the mechanism involved in glyphosate resistance in the RG biotype. RG biotype responses to the alternative treatments tested in situ indicated that herbicide applications at the later growth stage tended to be less effective in terms of immediate effects on population size than earlier applications, and that only in some cases, the removal of at least 85% of the RG biotype was achieved. However, with few

  2. Assessment of bone loss with repeated bone mineral measurements: Application to measurements on the individual patient

    Energy Technology Data Exchange (ETDEWEB)

    Wahner, H.W.

    1987-02-01

    Longitudinal measurements on lumbar spine and mid-radius were made by bone absorptiometry techniques in 139 normal women. Bone mineral was measured every 6 months over an median interval of 2.1 years. The results revealed that bone loss at different skeletal sites is non-uniform with equal bone loss patterns in all patients and relatively small variations in bone loss rate between normal women. For achieving these results there is strong demand on high precision and properly spaced measuring intervals for long-term rate of loss measurements. For exclusion of progressive degenerative disease a radiographic evaluation of the spine in the beginning and at the end of the study is mandatory as compression fractures or trauma reveal bone mineral changes independent from the agerelated bone loss. These repeated bone mineral measurements are useful for monitoring and follow-up studies during different therapeutic regimens.

  3. WEED CONTROL IN GENETICALLY MODIFIED GLYPHOSATE-TOLERANT SOYBEAN MANEJO DE PLANTAS DANINHAS EM SOJA GENETICAMENTE MODIFICADA TOLERANTE AO GLYPHOSATE

    Directory of Open Access Journals (Sweden)

    Júlio Cezar Durigan

    2011-04-01

    Full Text Available The transgenic production systems, as well as conventional systems, require, in addition to chemical control, the adoption of other weed management strategies. This study was developed to evaluate the weed chemical control in glyphosate tolerant soybean, associated to cover crops cultivated in the autumn/winter. The experiment was carried out under field conditions at the FCAV/Unesp, Jaboticabal, São Paulo State, Brazil. A randomized split-plot block design was used, with four replications. St. Lucia Grass (Brachiaria brizantha ‘Marandu’, forage millet (Pennisetum americanum ‘BN2’, and a treatment with spontaneous growth vegetation were evaluated for plots, and, for subplots, the herbicides glyphosate, chlorimuron - ethyl plus lactofen, and fluazifop-p-butyl, in a sequential spraying, and two controls without any application. Grass cover contributed to the chemical control, suppressing weeds, and the single application of 720 g a.e. ha-1 of glyphosate, independently of the cover crop cultivated in the autumn/winter, was sufficient for adequately controlling Acanthospermum hispidum, Alternanthera tenella, Amaranthus sp., Bidens pilosa, Xanthium strumarium, Cenchrus echinatus, Digitaria sp., and Eleusine indica, with results similar to the treatment (chlorimuron-ethyl + lactofen + fluazifop-p-buthyl. When compared to the weeded control, the herbicides did not affect plants height, dry matter of the aerial parts, mass of 100 grains, and grain yield. Soybean plants grown over St. Lucia Grass and forage millet presented a higher height, however, no other feature was influenced by the cover crop.

    KEY-WORDS: Brachiaria brizantha; Pennisetum americanum; no-tillage; Roundup Ready; spontaneous vegetation.

    Os sistemas de produção transgênicos, assim como os

  4. Adsorption of glyphosate and aminomethylphosphonic acid in soils

    Science.gov (United States)

    Rampazzo, N.; Rampazzo Todorovic, G.; Mentler, A.; Blum, W. E. H.

    2013-03-01

    The results showed that glyphosate is initially adsorbed mostly in the upper 2 cm. It is than transported and adsorbed after few days in deeper soil horizons with concomitant increasing content of its metabolite aminomethylphosphonic acid. Moreover, Fe-oxides seem to be a key parameter for glyphosate and aminomethylphosphonic adsorption in soils. This study confirmed previous studies: the analysis showed lower contents of dithionite-soluble and Fe-oxides for the Chernozem, with consequently lower adsorption of glyphosate and aminomethylphosphonic as compared with the Cambisol and the Stagnosol.

  5. 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

  6. Characterization of Halomonas Varabilis Strain HTG7 Conferring Glyphosate Resistance

    Institute of Scientific and Technical Information of China (English)

    Liu Zhu(刘柱); Liang Aimin; Ping Shuzhen; Zhang Wei; Chen Ming; Yang Zhirong; Lin Min

    2004-01-01

    Bcterial strain HTG7 is isolated from extremely glyphosate-polluted soil. It is identified as Halomonas Varabilis. It can tolerate in 500 m mol/L glyphosate concentration. Physiological characterization of strain HTG7 shows that the optimum pH and temperature are 7.0 and 30℃, respectively. It grows well in the NaCl concentrations ranging from 0% to 10%. A plasmid pACYC184 carrying a 3.5 kb DNA fragment, which confers increased glyphosate tolerance, is cloned. The DNA fragment is able to complement with an E.coli auxotrophic aroA mutant.

  7. Glyphosate on digestive enzymes activity in piava (Leporinus obtusidens

    Directory of Open Access Journals (Sweden)

    Joseânia Salbego

    2014-09-01

    Full Text Available The effects of glyphosate, a nonselective herbicide (1.0 or 5.0mg L-1 on digestive enzymes activity (stomach and intestine were evaluated in juveniles of piava (Leporinus obtusidens after 90 days of exposure. The activity of acid protease, trypsin, chymotrypsin and amylase increased with the increase of glyphosate concentration. These results indicate that glyphosate affects digestive enzyme activities in this species, and may be an indicator of poor nutrient availability when fish survive in herbicide-contaminated water.

  8. 锰盐沉淀法处理草甘膦废水的草甘膦回收试验%Reclamation of Glyphosate in Treatment of Glyphosate Wastewater by Manganese Chemical Sedimentation Process

    Institute of Scientific and Technical Information of China (English)

    袁志文; 宋艳艳

    2012-01-01

    草甘膦生产过程中产生的大量草甘膦废水至今无有效的回收方法.采用化学沉淀法处理草甘膦废水,试验结果表明:当投加的锰盐与模拟废水溶液中草甘膦的摩尔比值为1.0~1.3,pH为4.2~5.6时,草甘膦与锰盐反应沉淀,沉淀率可达96%以上.继续向回收的草甘膦锰盐沉淀中加酸使pH小于2.0,沉淀将重新溶解形成草甘膦过饱和溶液,静置后草甘膦重新结晶,得到纯度95%以上的草甘膦晶体.该技术应用到实际草甘膦废水处理中时,废水的高盐度和复杂成分显著降低了草甘膦的沉淀及结晶效率,限制了该技术的应用,其机理研究有着重大的理论和现实意义.%The large quantities of wastewater generated in the process of glyphosate production can not be recycled effectively now. The experiment showed that the addition of manganese salt into the aqueous solution of glyphosate(Mn2+/glyphosate=1.0~1.3,pH=4.2~ 5.6) could precipitate over 96 % of the glyphosate. By adding acid to the precipitation and making the pH of solution less than 2.0, the precipitation could be dissolved and became supersaturated aqueous solution of glyphosate, then glyphosate would crystallize, the purity of the crystal was above 95 %. When this technique was applied to the treatment of mother liquor of glyphosate, the efficiency of precipitation and crystallization decreased remarkably due to the complexity and high salinity of the mother liquid, and the application of this technology may be limited. Thus the mechanism research was highly theoretically and practically meaningful.

  9. The occurrence of glyphosate, atrazine, and other pesticides in vernal pools and adjacent streams in Washington, DC, Maryland, Iowa, and Wyoming, 2005-2006

    Science.gov (United States)

    Battaglin, William A.; Rice, Karen C.; Focazio, Michael J.; Salmons, Sue; Barry, Robert X.

    2009-01-01

    Vernal pools are sensitive environments that provide critical habitat for many species, including amphibians. These small water bodies are not always protected by pesticide label requirements for no-spray buffer zones, and the occurrence of pesticides in them is poorly documented. In this study, we investigated the occurrence of glyphosate, its primary degradation product aminomethylphosphonic acid, and additional pesticides in vernal pools and adjacent flowing waters. Most sampling sites were chosen to be in areas where glyphosate was being used either in production agriculture or for nonindigenous plant control. The four site locations were in otherwise protected areas (e.g., in a National Park). When possible, water samples were collected both before and after glyphosate application in 2005 and 2006. Twenty-eight pesticides or pesticide degradation products were detected in the study, and as many as 11 were identified in individual samples. Atrazine was detected most frequently and concentrations exceeded the freshwater aquatic life standard of 1.8 micrograms per liter (μg/l) in samples from Rands Ditch and Browns Ditch in DeSoto National Wildlife Refuge. Glyphosate was measured at the highest concentration (328 μg/l) in a sample from Riley Spring Pond in Rock Creek National Park. This concentration exceeded the freshwater aquatic life standard for glyphosate of 65 μg/l. Aminomethylphosphonic acid, triclopyr, and nicosulfuron also were detected at concentrations greater than 3.0 μg/l.

  10. Urinary excretion of phthalates and paraben after repeated whole-body topical application in humans

    DEFF Research Database (Denmark)

    Janjua, Nadeem Rezaq; Frederiksen, Hanne; Skakkebaek, Niels E

    2008-01-01

    were given a whole body topical application of basic cream 2 mg/cm(2) (control week) and then a cream containing 2% (w/w) of DEP, DBP and BP each (treatment week) daily. Twenty-four-hour urine samples were collected. Urinary total, and unconjugated BP, monoethyl phthalate (MEP) and monobutyl phthalate...... through dermal absorption, but there are no published data on absorption, metabolism, and excretion after dermal application. This study investigates urinary concentrations of BP and metabolites of DEP and DBP after topical application. In a 2-week single-blinded study, 26 healthy Caucasian male subjects...... (MBP) metabolites were analysed by Liquid Chromatography-Tandem Mass Spectroscopy (LC-MS/MS). All 26 subjects showed increased excretion of MEP, MBP and BP following topical application. Total MEP, MBP and BP (mean +/- SEM) excreted in urine in the treatment week were, respectively, 41 +/- 1.9, 11...

  11. Monitoring heavy metal concentrations in leachates from a forest soil subjected to repeated applications of sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Egiarte, G.; Pinto, M. [NEIKER-Basque Institute of Agricultural Research and Development, Berreaga, 1, 48160 Derio, Bizkaia, Basque Country (Spain); Ruiz-Romera, E. [Departamento de Quimica e Ingenieria Ambiental, Escuela de Ingenieros, Alameda Urquijo, s/n. 48013 Bilbo, UPV, Basque Country (Spain); Camps Arbestain, M. [NEIKER-Basque Institute of Agricultural Research and Development, Berreaga, 1, 48160 Derio, Bizkaia, Basque Country (Spain)], E-mail: mcamps@neiker.net

    2008-12-15

    The aim of the study was to establish whether the repeated application of sewage sludge to an acid forest soil (Dystric Cambisol) would lead to short-term groundwater contamination. Sludge was applied at four loading rates (0, 2.4, 17 and 60 Mg ha{sup -1}) in two consecutive years and leachates were analysed. Heavy metal inputs to soils at the lowest dose were below EC regulations but, at higher doses, limits for Zn, Cd, Cr and Ni were exceeded. Repeated application of sludge at 60 Mg ha{sup -1} resulted in significantly (P < 0.05) higher concentrations of Zn, Cd, Cr and Ni in the leachates than with other treatments. The drinking water standards for Cd and Ni were surpassed in all treatments. Control plots were contaminated by groundwater flow despite the existence of buffer zones between plots. This complicated interpretation of the results, highlighting the importance of careful design of this type of experiment. - The experimental design of field studies on groundwater contamination by soil amendments should ensure that subsurface lateral flow does not occur between plots.

  12. Combining glyphosate with burning or mowing improves control of Yellow Bluestem (Bothriochloa ischaemum)

    Science.gov (United States)

    Robertson, S.; Hickman, Karen R.; Harmoney, Keith R.; Leslie,, David M.

    2013-01-01

    The invasive yellow bluestem (Bothriochloa ischaemum [L.] Keng) threatens native biodiversity, and its control is of interest to land managers involved in restoration of invaded grasslands. We used single, double, and triple applications of glyphosate (2.125 kg ai.ha-1.application-1) over the course of one growing season in combinations at different timings (early, middle, late season) with and without a mechanical treatment of mowing or burning to determine the most effective control method. One year after treatment, burning and mowing prior to a mid-season single or double early, middle, and/or late season herbicide application resulted in a similar level of control of yellow bluestem relative to a triple herbicide application, all of which had greater control relative to herbicide treatment alone. Reproductive tiller density and visual obstruction increased 2 yr after treatment with two herbicide treatments applied either early and middle season or early and late season, but it was prevented with burning and mowing prior to herbicide application. With the exception of three herbicide applications, combining burning or mowing with herbicide applications provided more effective control of yellow bluestem than any individual herbicide applications. Burning or mowing likely improves glyphosate effectiveness by altering the invasive grass structure so that plants are clear of standing dead and have shorter, active regrowth to enhance herbicide effectiveness. During restoration projects requiring control of invasive yellow bluestem, an effective management option is a combination of mechanical and chemical control.

  13. Persistence and distribution of 4-nonylphenol following repeated application to littoral enclosures

    Energy Technology Data Exchange (ETDEWEB)

    Heinis, L.J.; Liber, K.; Tunell, R.L. [Univ. of Wisconsin, Superior, WI (United States). Lake Superior Research Inst.; Knuth, M.L.; Sheedy, B.R.; Ankley, G.T. [Environmental Protection Agency, Duluth, MN (United States). Mid-Continent Ecology Div.

    1999-03-01

    The persistence and distribution of 4-nonylphenol (NP) were monitored for 440 d, following application to 18 littoral enclosures situated in a 2-ha mesotrophic pond near Duluth, Minnesota. Application was accomplished by subsurface, gravity-fed injection over a 20-d period, with a 2-d frequency, to achieve nominal aqueous concentrations of 0, 3, 30, 100, and 300 {micro}g/L. Mean maximum concentrations in the water over the 20-d application period ranged from 75.7 to 81.0% of nominal for the three highest treatment levels and was 181% of nominal at the lowest treatment level. Water was the major compartment, on a mass balance basis, for NP until 2 to 4 d after the application period, with a mean time to 50% dissipation (DT50) of 0.74 d and a mean time to 95% dissipation (DT95) of 13.8 d. 4-Nonylphenol partitioned to enclosure wall material, macrophytes, and sediment within 2 d of initial application. Macrophytes accumulated maximum NP concentrations of 11.5 and 139 mg/kg 1 to 2 d after the application period at the 30- and 300-{micro}g/L treatment levels, respectively. Mean DT50 and DT95 estimates of NP persistence in/on the macrophytes were 10.3 and 189 d, respectively. Sediment from the 30- and 300-{micro}g/L treatments accumulated maximum dry weight NP concentrations of 2.74 and 27.4 mg/kg, respectively within 20 to 48 d of the first application. The mean sediment porewater NP concentration was 18.6 {micro}g/L for the period 2 to 34 d after application 1 at the 300-{micro}g/L treatment. The sediment was the primary sink for NP 440 d after the initial application with a concentration of 1.97 mg/kg at the 300-{micro}g/L treatment. Mean sediment DT50 and DT95 values were 66.0 and 401 d, respectively, indicating a long-term persistence of NP. Ecocores collected 1 d after the final NP application did not show significant decreases in sediment NP concentration during a 55-d incubation period, corroborating the NP persistence observed in the littoral enclosures.

  14. Establishment of PCR-ELISA for Detecting Glyphosate Resistant Transgenic Soybean

    Institute of Scientific and Technical Information of China (English)

    Yuan Qiang; Wei Yun-min; Fu Ming-ming; Qiu You-wen; Wen Hong-tao; Zhang Ming-hui; Liu Ying; Ao Jin-xia

    2016-01-01

    A PCR-ELISA method for detecting the glyphosate resistant transgenic soybean was established and optimized. The results showed that the key parameters of PCR-ELISA were as follows: the concentration of digoxin tag probe was 0.5 μmol• L-1, the time of hybridization reaction was 15 min and the chromogenic reaction should last for 30 min. The sensitivity and the repeatability of our PCR-ELISA method were evaluated, and the results showed that it could be detected when the concentration of DNA template from transgenic soybean samples was 0.01% or higher, and the coefficient of variation of this method was less than 5% in our research condition. These results suggested that PCR-ELISA method establishment in this study had good repeatability and high precision for detecting the transgenic soybean samples.

  15. Efeito de doses reduzidas de glyphosate e paraquat simulando deriva na cultura do sorgo Effect of reduced rates of glyphosate and paraquat simulating drift on sorghum crop

    Directory of Open Access Journals (Sweden)

    P.C. Magalhães

    2001-08-01

    glyphosate como de paraquat, correspondentes a 12% ou menos da dose recomendada, podem influir no desenvolvimento das plantas, comprometendo a produtividade de grãos, sobretudo quando as condições climáticas são favoráveis à ação desses herbicidas.Herbicide application for crop desiccation or weed control has been growing due to the expansion of the Brazilian agricultural frontier. This fact increases the risks of drift to susceptible crops grown in the vicinity areas; however, several questions are frequently raised about possible losses in grain yield of these crops due to herbicide drift. The objective of this work was to evaluate injuries caused by reduced rates of glyphosate and paraquat simulating drift and its effect on sorghum plant development and grain production. The study was carried out during the crop growing seasons of 1996/97 and 1997/98. The hybrid BR 700 was used in a randomized complete block design, with 12 treatments and four replications. The treatments were performed by the combination of two herbicides with five concentrations of simulated drift: 2, 4, 6, 8 and 12% of the recommended rates (1,440 g ha-1 of glyphosate and 400 g ha-1 of paraquat, and two check treatments without herbicide application for compressions. Leaf area and dry matter weight were not affected by drift, whereas plant height was reduced, especially by the highest herbicide reduced rate. The chlorophyll content was slightly affected in the growing season 1997/98, whereas the visual symptoms, in both growing seasons, resulted in higher percentage of injuries while concentration drift increased. The leaf damages observed were greater at the growing season 1996/97. Also in this growing season, the final stand was reduced by the highest glyphosate rate. As far as grain production is concerned, only the growing season 1996/97 presented yield reduction due to drift, when the highest rate of glyphosate resulted in the lowest grain weight. In the 1997/98 trial, there was no drift

  16. Eficiência fotossintética e uso da água em plantas de eucalipto pulverizadas com glyphosate Photosynthetic efficiency and water use in eucalyptus plants sprayed with glyphosate

    Directory of Open Access Journals (Sweden)

    A.F.L. Machado

    2010-06-01

    after herbicide application (DAA, plant intoxication was evaluated and at 7 and 21 DAA, stomatal gas flow (U - mmol s-1, photosynthetic activity (A -mmol m-2 s-1, stomatal conductance (Gs - mol m-1 s-1, transpiration (E - mol H2O m-2 s-1 and water use efficiency (WUE - mol CO2 mol H2O-1. At 50 DAA, the eucalyptus plants were collected and placed in a forced-ventilation oven at 70 °C until constant weight to determine dry mass. At 21 DAA, clone 1203 was found to be the most sensitive to the herbicide. There was no difference among the clones for the assessed physiological variables. At 21DAA, it was verified that increasing doses of glyphosate led to a reduction in stomatal conductance, stomatal gas flow rate, photosynthetic rate and water use efficiency. Plants of clones 1213 and 1203 showed a higher accumulation of dry mass. Increasing doses of glyphosate promoted less accumulation of dry mass in the eucalyptus plants. Glyphosate negatively affected growth, photosynthetic efficiency and water use of the evaluated clones.

  17. Reliability characteristics and applicability of a repeated sprint ability test in male young soccer players.

    Science.gov (United States)

    Castagna, Carlo; Francini, Lorenzo; Krustrup, Peter; Fenarnandes-da-Silva, Juliano; Póvoas, Susana C A; Bernardini, Andrea; D'Ottavio, Stefano

    2017-07-28

    The aim of this study was to examine the usefulness and reliability characteristics of a repeated sprint ability test considering 5 line sprints of 30-m interspersed with 30-s of active recovery in non-elite outfield young male soccer players. Twenty-six (age 14.9±1.2 years, height 1.72±0.12 cm, body mass 62.2±5.1 kg) players were tested 48 hours and 7 days apart for 5x30-m performance over 5 trials (T1-T5). Short- (T1-T2) and long-term reliability (T1-T3-T4-T5) were assessed with Intraclass Correlation Coefficient (ICC) and with typical error for measurement (TEM). Short- and long-term reliability ICCs and TEMs for total sprint time and best sprint performance were nearly perfect and satisfactory, respectively. Usefulness (as smallest worthwhile change and TEM ratio) resulted acceptable (i.e =1) and good (i.e >1) for total sprint time and best sprint performance, respectively. The present study revealed that the 5x30-m sprint test is a reliable field test in the short and long-term when the sum of sprint times and the best sprint performance are considered as outcome variables. Sprint performance decrements variables showed large variability across trials.

  18. Percutaneous absorption of diclofenac in healthy volunteers after single and repeated topical application of diclofenac Emulgel.

    Science.gov (United States)

    Sioufi, A; Pommier, F; Boschet, F; Godbillon, J; Lavoignat, D; Salliere, D

    1994-08-01

    The percutaneous absorption of diclofenac was studied in ten healthy volunteers treated with Emulgel containing 1.16% diclofenac diethylammonium for 8 d as follows: a single application of 5 g Emulgel on days 1 and 8, and two applications d-1 on days 2-7. Plasma concentration profiles of unchanged diclofenac and urinary concentrations of total diclofenac and metabolites (sum of free and conjugated) were determined. High inter-individual variations in plasma and urine data were recorded, due probably to the permeability and the hydration of the skin. Steady state was reached after 2 d of twice-daily administration. Plasma concentrations were low but remained in the range 10-50 nmol L-1 over the full day for most of the subjects, indicating prolonged absorption from the application site.

  19. Evolved glyphosate-resistant weeds around the world: lessons to be learnt.

    Science.gov (United States)

    Powles, Stephen B

    2008-04-01

    Glyphosate is the world's most important herbicide, with many uses that deliver effective and sustained control of a wide spectrum of unwanted (weedy) plant species. Until recently there were relatively few reports of weedy plant species evolving resistance to glyphosate. Since 1996, the advent and subsequent high adoption of transgenic glyphosate-resistant crops in the Americas has meant unprecedented and often exclusive use of glyphosate for weed control over very large areas. Consequently, in regions of the USA where transgenic glyphosate-resistant crops dominate, there are now evolved glyphosate-resistant populations of the economically damaging weed species Ambrosia artemissifolia L., Ambrosia trifida L., Amaranthus palmeri S Watson, Amaranthus rudis JD Sauer, Amaranthus tuberculatus (Moq) JD Sauer and various Conyza and Lolium spp. Likewise, in areas of transgenic glyphosate-resistant crops in Argentina and Brazil, there are now evolved glyphosate-resistant populations of Sorghum halepense (L.) Pers and Euphorbia heterophylla L. respectively. As transgenic glyphosate-resistant crops will remain very popular with producers, it is anticipated that glyphosate-resistant biotypes of other prominent weed species will evolve over the next few years. Therefore, evolved glyphosate-resistant weeds are a major risk for the continued success of glyphosate and transgenic glyphosate-resistant crops. However, glyphosate-resistant weeds are not yet a problem in many parts of the world, and lessons can be learnt and actions taken to achieve glyphosate sustainability. A major lesson is that maintenance of diversity in weed management systems is crucial for glyphosate to be sustainable. Glyphosate is essential for present and future world food production, and action to secure its sustainability for future generations is a global imperative.

  20. Glyphosate-resistant weeds of South American cropping systems: an overview.

    Science.gov (United States)

    Vila-Aiub, Martin M; Vidal, Ribas A; Balbi, Maria C; Gundel, Pedro E; Trucco, Frederico; Ghersa, Claudio M

    2008-04-01

    Herbicide resistance is an evolutionary event resulting from intense herbicide selection over genetically diverse weed populations. In South America, orchard, cereal and legume cropping systems show a strong dependence on glyphosate to control weeds. The goal of this report is to review the current knowledge on cases of evolved glyphosate-resistant weeds in South American agriculture. The first reports of glyphosate resistance include populations of highly diverse taxa (Lolium multiflorum Lam., Conyza bonariensis L., C. canadensis L.). In all instances, resistance evolution followed intense glyphosate use in fruit fields of Chile and Brazil. In fruit orchards from Colombia, Parthenium hysterophorus L. has shown the ability to withstand high glyphosate rates. The recent appearance of glyphosate-resistant Sorghum halepense L. and Euphorbia heterophylla L. in glyphosate-resistant soybean fields of Argentina and Brazil, respectively, is of major concern. The evolution of glyphosate resistance has clearly taken place in those agroecosystems where glyphosate exerts a strong and continuous selection pressure on weeds. The massive adoption of no-till practices together with the utilization of glyphosate-resistant soybean crops are factors encouraging increase in glyphosate use. This phenomenon has been more evident in Argentina and Brazil. The exclusive reliance on glyphosate as the main tool for weed management results in agroecosystems biologically more prone to glyphosate resistance evolution.

  1. Pisolithus sp. tolerance to glyphosate and isoxaflutole in vitro

    Directory of Open Access Journals (Sweden)

    Mayara Cristina Silva Fernandes

    2014-06-01

    Full Text Available The ectomycorrhizal fungi have different tolerance to herbicides and may promote the survival and growth of the eucalypts tree. This study aimed to evaluate the tolerance of Pisolithus sp. isolates to glyphosate and isoxaflutole. The isolates evaluated were D3, D16, D17, Pt24 and UFVJM04. Glyphosate concentrations were: 0, 32, 63, 127 and 254 mg L-1 in liquid medium; 0, 32, 63, 127, 254, 507 and 1014 mg L-1 in solid medium. For isoxaflutole, the concentrations were 0, 295, 589, 1178 and 2355 mg L-1 for both media. Assays were independent for each herbicide and culture medium. The tolerance of isolates depended on the herbicide and its concentration in each type of culture medium. Pt24 was the most tolerant to glyphosate and the UFVJM04 to isoxaflutole. Glyphosate was more toxic to isolates of Pisolithus than isoxaflutole.

  2. [Effect of glyphosate on the energy exchange in carp organs].

    Science.gov (United States)

    Zhidenko, A A; Bibchuk, E V; Barbukho, E V

    2013-01-01

    The use of glyphosate as a herbicide in agriculture can lead to the presence of its residues and metabolites (aminomethylphosphonic acid) in food for human consumption and pose a threat to health. The effect of these herbicides on the fish organism at the biochemical level has been insufficiently studied. We studied changes in the content of adenine nucleotides, enzyme activity, quantitative indexes of energy metabolism substrates in carp under the action of glyphosate. It has been found that proteins are the major energy substrate under the influence of glyphosate in the liver, brain, white muscle of carp yearlings. Glyphosphate decreases energy metabolism in the brain of carp and increases it in the white muscles. The growth of activity of catabolic enzymes in the liver under the influence of glyphosate can be attributed to the adaptive remodelling of metabolic pathways for homeostasis and enantiostasis in response to herbicides.

  3. Modeling biodegradation and kinetics of glyphosate by artificial neural network.

    Science.gov (United States)

    Nourouzi, Mohsen M; Chuah, Teong G; Choong, Thomas S Y; Rabiei, F

    2012-01-01

    An artificial neural network (ANN) model was developed to simulate the biodegradation of herbicide glyphosate [2-(Phosphonomethylamino) acetic acid] in a solution with varying parameters pH, inoculum size and initial glyphosate concentration. The predictive ability of ANN model was also compared with Monod model. The result showed that ANN model was able to accurately predict the experimental results. A low ratio of self-inhibition and half saturation constants of Haldane equations (glyphosate on bacteria growth. The value of K(i)/K(s) increased when the mixed inoculum size was increased from 10(4) to 10(6) bacteria/mL. It was found that the percentage of glyphosate degradation reached a maximum value of 99% at an optimum pH 6-7 while for pH values higher than 9 or lower than 4, no degradation was observed.

  4. Partial desalination and concentration of glyphosate liquor by nanofiltration.

    Science.gov (United States)

    Xie, Ming; Xu, Yanhua

    2011-02-15

    Partial desalination and concentration of glyphosate liquor by nanofiltration under different operation modes were investigated experimentally in this study. These operation modes were direct nanofiltration, diafiltration, dilute-diafiltration and interval washing-nanofiltration. The four different operation modes were evaluated and compared in terms of glyphosate recovery and NaCl removal. Diafiltration and dilute-diafiltration performed better than direct nanofiltration. The glyphosate loss was between 11.5% and 18.8% when the dilution factor varied from 0.4 to 0.8. Interval washing-nanofiltration alleviated the concentration polarization and membrane fouling to a certain extent. Dilute-diafiltration may be the best operation mode in terms of glyphosate recovery, salt removal and cost.

  5. Quantum repeated games revisited

    CERN Document Server

    Frackiewicz, Piotr

    2011-01-01

    We present a scheme for playing quantum repeated 2x2 games based on the Marinatto and Weber's approach to quantum games. As a potential application, we study twice repeated Prisoner's Dilemma game. We show that results not available in classical game can be obtained when the game is played in the quantum way. Before we present our idea, we comment on the previous scheme of playing quantum repeated games.

  6. 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

  7. Transgenic tobacco simultaneously overexpressing glyphosate N-acetyltransferase and 5-enolpyruvylshikimate-3-phosphate synthase are more resistant to glyphosate than those containing one gene.

    Science.gov (United States)

    Liu, Yunjun; Cao, Gaoyi; Chen, Rongrong; Zhang, Shengxue; Ren, Yuan; Lu, Wei; Wang, Jianhua; Wang, Guoying

    2015-08-01

    5-Enolpyruvylshikimate-3-phosphate synthase (EPSPS) and glyphosate N-acetyltransferase (GAT) can detoxify glyphosate by alleviating the suppression of shikimate pathway. In this study, we obtained transgenic tobacco plants overexpressing AM79 aroA, GAT, and both of them, respectively, to evaluate whether overexpression of both genes could confer transgenic plants with higher glyphosate resistance. The transgenic plants harboring GAT or AM79 aroA, respectively, showed good glyphosate resistance. As expected, the hybrid plants containing both GAT and AM79 aroA exhibited improved glyphosate resistance than the transgenic plants overexpressing only a single gene. When grown on media with high concentration of glyphosate, seedlings containing a single gene were severely inhibited, whereas plants expressing both genes were affected less. When transgenic plants grown in the greenhouse were sprayed with glyphosate, less damage was observed for the plants containing both genes. Metabolomics analysis showed that transgenic plants containing two genes could maintain the metabolism balance better than those containing one gene after glyphosate treatment. Glyphosate treatment did not lead to a huge increase of shikimate contents of tobacco leaves in transgenic plants overexpressing two genes, whereas significant increase of shikimate contents in transgenic plants containing only a single gene was observed. These results demonstrated that pyramiding both aroA and GAT in transgenic plants can enhance glyphosate resistance, and this strategy can be used for the development of transgenic glyphosate-resistant crops.

  8. Dynamics of changes in methanogenesis and associated microflora in a flooded alluvial soil following repeated application of dicyandiamide, a nitrification inhibitor.

    Science.gov (United States)

    Mohanty, S R; Bharati, K; Rao, V R; Adhya, T K

    2009-01-01

    Influence of repeated application of the nitrification inhibitor dicyandiamide (DCD), on CH(4) production and associated microflora in a flooded alluvial soil, was investigated in a laboratory incubation study. Application of DCD at the time of soil incubation resulted in a substantial reduction in CH(4) production (31% over that of untreated control). Second repeat application of DCD, on the contrary, annulled the inhibitory effect on CH(4) production, restoring it to the level of unamended soil. Application of the third dose of DCD maintained CH(4) production almost to the same extent as that of second application. The alleviation of the initial inhibitory effect of DCD on CH(4) production was linked to the enhanced degradation of DCD following its repeated application to the flooded soil. Admittedly, abatement of the initial inhibitory effect of DCD on CH(4) production in soil repeatedly amended with DCD was also related to the inhibition of CH(4)-oxidizing bacterial population and noticeable stimulation of heterotrophic bacterial population. Results suggest that repeat application of DCD with fertilizer-N to flooded rice soils might not be effective in controlling CH(4) production under field condition.

  9. Tracing the origin and mobilization of Glyphosate and AMPA in a vineyard catchment

    Science.gov (United States)

    Gassmann, Matthias; Olsson, Oliver; Payraudeau, Sylvain; Imfeld, Gwenaël; Kümmerer, Klaus

    2014-05-01

    Pesticides residues are often found in storm-water runoff in agricultural areas. There are several pathways along which pesticides may be transported from their application point towards the river. Although the primary target of pesticide application is the agricultural area, wind drift transports pesticide droplets to non-target areas. Furthermore, miss-operation of application machines results in the deposition of pesticides at filter strips or roads from where they can be washed off. Therefore, it may be difficult to identify the origin of pesticides in storm-water runoff. However, management of water quality requires that critical source areas are clearly delineated in order to effectively reduce water pollution. In the Rouffach catchment, a 42.7 ha vineyard catchment in France, Glyphosate and its transformation product AMPA occurred frequently and in high concentrations in runoff water during rainfall-runoff events in 2008. In order to identify the source areas of Glyphosate residue pollution and its mobilization, we used here a combination of sampling data analysis techniques and distributed pollutant transfer modelling. Available sampling data allowed for an analysis by Normalized Cumulative Loads (NCL) at a high temporal resolution (10 min). The results imply that pollutant mobilization took place mainly at the beginning of an event. This First Flush suggests a wash off of substances from impervious surfaces such as roads. This assumption was confirmed by local hydrological knowledge about infiltration rates in the vineyard, which were not exceeded by rainfall intensities in most considered events. Additionally, the distributed process-based reactive transport model ZIN-AgriTra was used as a learning tool to evaluate the pesticide mobilization and export processes. The hydrological model was successfully calibrated and validated for long high-resolution time series of discharge data. Pesticide export modelling focused on the first rainfall-runoff event

  10. Tolerância do Tifton 85 (Cynodon spp. e da Brachiaria brizantha ao glyphosate Tifton 85 (Cynodon spp. and Brachiaria brizantha tolerance to glyphosate

    Directory of Open Access Journals (Sweden)

    M.V. Santos

    2008-06-01

    .440; 2.160; and 2.880 g ha-1 of glyphosate were tested in to an experiment arranged in a randomized block design, with four replicates divided into 3.5 m x 3.0 m, totaling 10.5 m², and only 7.5 m² of useful area. Herbicide efficiency in B. brizantha control and intoxication level on Tifton 85 plants were evaluated at 15, 30 and 60 days after application (DAA, following the scale from 0 (absence of control and/or intoxication to 100 (total control or plant death. At 300 DAA, the forage plants of both species were cut and dried to evaluate production and sprouting potential. Control superior to 90% of B. brizantha plants was observed from 1,473.75 and 1,721.25 g ha-1 of glyphosate rates, respectively at 30 and 60 DAA. The intoxication of Tifton 85 plants referring to B. brizantha control rates were 24.90 and 4.13%, respectively. At 60 DAA, 18.22% of Tifton 85 plants intoxication was observed at the highest rate evaluated (2.880 g ha-1 of glyphosate. Absence of B. brizantha dry matter production occurred at 300 DAA, at 2.160 g ha¹ herbicide rate as a result of efficient control. Results showed higher tolerance of Tifton 85 plants to glyphosate in relation to B. brizantha plants, allowing this species control in established Tifton 85 pasture, with no damage to the cultivated forage.

  11. First resistance mechanisms characterization in glyphosate-resistant Leptochloa virgata.

    Directory of Open Access Journals (Sweden)

    Ricardo Alcántara-de la Cruz

    2016-11-01

    Full Text Available Leptochloa virgata (L. P. Beauv. is an annual weed common in citrus groves in the states of Puebla and Veracruz, Mexico limiting their production. Since 2010, several L. virgata populations were identified as being resistant to glyphosate, but studies of their resistance mechanisms developed by this species have been conducted. In this work, three glyphosate-resistant populations (R8, R14 and R15 collected in citrus orchards from Mexico, were used to study their resistance mechanisms comparing them to one susceptible population (S. Dose-response and shikimic acid accumulation assays confirmed the glyphosate resistance of the three resistant populations. Higher doses of up to 720 g ae ha-1 (field dose were needed to control by 50% plants of resistant populations. The S population absorbed between 7 and 13% more 14C-glyphosate than resistant ones, and translocated up to 32.2% of 14C-glyphosate to the roots at 96 h after treatment (HAT. The R8, R14 and R15 populations translocated only 24.5, 26.5 and 21.9%, respectively. The enzyme activity of 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS was not different in the S, R8 and R14 populations. The R15 Population exhibited 165.9 times greater EPSPS activity. Additionally, this population showed a higher EPSPS basal activity and a substitution in the codon 106 from Proline to Serine in the EPSPS protein sequence. EPSPS gene expression in the R15 population was similar to that of S population. In conclusion, the three resistant L. virgata populations show reduced absorption and translocation of 14C-glyphosate. Moreover, a mutation and an enhanced EPSPS basal activity at target-site level confers higher resistance to glyphosate. These results describe for the first time the glyphosate resistance mechanisms developed by resistant L. virgata populations of citrus orchards from Mexico.

  12. First Resistance Mechanisms Characterization in Glyphosate-Resistant Leptochloa virgata

    Science.gov (United States)

    Alcántara-de la Cruz, Ricardo; Rojano-Delgado, Antonia M.; Giménez, María J.; Cruz-Hipolito, Hugo E.; Domínguez-Valenzuela, José A.; Barro, Francisco; De Prado, Rafael

    2016-01-01

    Leptochloa virgata (L.) P. Beauv. is an annual weed common in citrus groves in the states of Puebla and Veracruz, Mexico limiting their production. Since 2010, several L. virgata populations were identified as being resistant to glyphosate, but studies of their resistance mechanisms developed by this species have been conducted. In this work, three glyphosate-resistant populations (R8, R14, and R15) collected in citrus orchards from Mexico, were used to study their resistance mechanisms comparing them to one susceptible population (S). Dose-response and shikimic acid accumulation assays confirmed the glyphosate resistance of the three resistant populations. Higher doses of up to 720 g ae ha-1 (field dose) were needed to control by 50% plants of resistant populations. The S population absorbed between 7 and 13% more 14C-glyphosate than resistant ones, and translocated up to 32.2% of 14C-glyphosate to the roots at 96 h after treatment (HAT). The R8, R14, and R15 populations translocated only 24.5, 26.5, and 21.9%, respectively. The enzyme activity of 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS) was not different in the S, R8 and R14 populations. The R15 Population exhibited 165.9 times greater EPSPS activity. Additionally, this population showed a higher EPSPS basal activity and a substitution in the codon 106 from Proline to Serine in the EPSPS protein sequence. EPSPS gene expression in the R15 population was similar to that of S population. In conclusion, the three resistant L. virgata populations show reduced absorption and translocation of 14C-glyphosate. Moreover, a mutation and an enhanced EPSPS basal activity at target-site level confers higher resistance to glyphosate. These results describe for the first time the glyphosate resistance mechanisms developed by resistant L. virgata populations of citrus orchards from Mexico. PMID:27917189

  13. Glyphosate impairs male offspring reproductive development by disrupting gonadotropin expression

    OpenAIRE

    Romano, Marco Aurelio; ROMANO, Renata Marino; Santos, Luciana Dalazen; Wisniewski, Patricia; Campos, Daniele Antonelo; Souza, Paula Bargi de; Viau,Priscila; Bernardi, Maria Martha; Nunes, Maria Tereza; Oliveira,Claudio Alvarenga de

    2012-01-01

    Sexual differentiation in the brain takes place from late gestation to the early postnatal days. This is dependent on the conversion of circulating testosterone into estradiol by the enzyme aromatase. The glyphosate was shown to alter aromatase activity and decrease serum testosterone concentrations. Thus, the aim of this study was to investigate the effect of gestational maternal glyphosate exposure (50 mg/kg, NOAEL for reproductive toxicity) on the reproductive development of male offspring...

  14. Características da epiderme foliar de eucalipto e seu envolvimento com a tolerância ao glyphosate Characteristics of eucalypt leaf epidermis and its role in glyphosate tolerance

    Directory of Open Access Journals (Sweden)

    L.D. Tuffi Santos

    2006-09-01

    o comportamento diferencial de genótipos diante da deriva de glyphosate.In reforestation areas, glyphosate drift causes injuries in Eucalyptus plants. Preliminary research work and field observations point out a differential tolerance to glyphosate among cultivated genotypes. Within this context, the anatomical structures of leaf epidermis of five species of eucalypt, correlated to glyphosate tolerance under simulated drift were studied. The factorial design was used, with the species (Eucalyptus urophylla, E. grandis, E. pellita, E. resinifera and E. saligna and 05 subdoses (0, 43.2, 86.4, 172.8 and 345.6 g e.a. ha-1 of glyphosate simulating a drift. Immediately before herbicide application, totally expanded leaves were collected for anatomical analysis of epidermal surface through dissociation methodology. Among the studied species, E. resinifera was found to be the most tolerant to glyphosate drift, presenting the lowest values for intoxication percentage 45 days post-application, with no difference among the others. The five species present glabrous, amphistomatic leaves with anomocytic type stomata and prominent cuticle. Despite being present on both faces, stomata are rare on the adaxial face, exhibiting low index and stomatic density. The highest values for stomatic index were observed on E. resinifera, while E. saligna presented the highest stomatic density. Subepidermic cavities evidenced on the surface by the overlying cells are present in the five species, with the highest density on E. pellita. A high correlation was found between intoxication percentage and number of epidermic cells on the adaxial surface, indicating the involvement of this characteristic with differential tolerance to the herbicide. Studies on absorption, translocation and metabolism of glyphosate in eucalypt must be undertaken to elucidate the differential behaviour of genotypes concerning glyphosate drift.

  15. Synthesize, optimize, analyze, repeat (SOAR): Application of neural network tools to ECG patient monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Watrous, R.; Towell, G.; Glassman, M.S. [Siemens Corporate Research, Princeton, NJ (United States)

    1995-12-31

    Results are reported from the application of tools for synthesizing, optimizing and analyzing neural networks to an ECG Patient Monitoring task. A neural network was synthesized from a rule-based classifier and optimized over a set of normal and abnormal heartbeats. The classification error rate on a separate and larger test set was reduced by a factor of 2. When the network was analyzed and reduced in size by a factor of 40%, the same level of performance was maintained.

  16. Population genetics structure of glyphosate-resistant Johnsongrass (Sorghum halepense L. Pers) does not support a single origin of the resistance.

    Science.gov (United States)

    Fernández, Luis; de Haro, Luis Alejandro; Distefano, Ana J; Carolina Martínez, Maria; Lía, Verónica; Papa, Juan C; Olea, Ignacio; Tosto, Daniela; Esteban Hopp, Horacio

    2013-09-01

    Single sequence repeats (SSR) developed for Sorghum bicolor were used to characterize the genetic distance of 46 different Sorghum halepense (Johnsongrass) accessions from Argentina some of which have evolved toward glyphosate resistance. Since Johnsongrass is an allotetraploid and only one subgenome is homologous to cultivated sorghum, some SSR loci amplified up to two alleles while others (presumably more conserved loci) amplified up to four alleles. Twelve SSR providing information of 24 loci representative of Johnsongrass genome were selected for genetic distance characterization. All of them were highly polymorphic, which was evidenced by the number of different alleles found in the samples studied, in some of them up to 20. UPGMA and Mantel analysis showed that Johnsongrass glyphosate-resistant accessions that belong to different geographic regions do not share similar genetic backgrounds. In contrast, they show closer similarity to their neighboring susceptible counterparts. Discriminant Analysis of Principal Components using the clusters identified by K-means support the lack of a clear pattern of association among samples and resistance status or province of origin. Consequently, these results do not support a single genetic origin of glyphosate resistance. Nucleotide sequencing of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) encoding gene from glyphosate-resistant and susceptible accessions collected from different geographic origins showed that none presented expected mutations in aminoacid positions 101 and 106 which are diagnostic of target-site resistance mechanism.

  17. Root-Zone Glyphosate Exposure Adversely Affects Two Ditch Species

    Directory of Open Access Journals (Sweden)

    Lyndsay E. Saunders

    2013-12-01

    Full Text Available Glyphosate, one of the most applied herbicides globally, has been extensively studied for its effects on non-target organisms. In the field, following precipitation, glyphosate runs off into agricultural ditches where it infiltrates into the soil and thus may encounter the roots of vegetation. These edge-of-field ditches share many characteristics with wetlands, including the ability to reduce loads of anthropogenic chemicals through uptake, transformation, and retention. Different species within the ditches may have a differential sensitivity to exposure of the root zone to glyphosate, contributing to patterns of abundance of ruderal species. The present laboratory experiment investigated whether two species commonly found in agricultural ditches in southcentral United States were affected by root zone glyphosate in a dose-dependent manner, with the objective of identifying a sublethal concentration threshold. The root zone of individuals of Polygonum hydropiperoides and Panicum hemitomon were exposed to four concentrations of glyphosate. Leaf chlorophyll content was measured, and the ratio of aboveground biomass to belowground biomass and survival were quantified. The findings from this study showed that root zone glyphosate exposure negatively affected both species including dose-dependent reductions in chlorophyll content. P. hydropiperdoides showed the greatest negative response, with decreased belowground biomass allocation and total mortality at the highest concentrations tested.

  18. Pool of resistance mechanisms to glyphosate in Digitaria insularis.

    Science.gov (United States)

    de Carvalho, Leonardo Bianco; Alves, Pedro Luis da Costa Aguiar; González-Torralva, Fidel; Cruz-Hipolito, Hugo Enrique; Rojano-Delgado, Antonia María; De Prado, Rafael; Gil-Humanes, Javier; Barro, Francisco; de Castro, María Dolores Luque

    2012-01-18

    Digitaria insularis biotypes resistant to glyphosate have been detected in Brazil. Studies were carried out in controlled conditions to determine the role of absorption, translocation, metabolism, and gene mutation as mechanisms of glyphosate resistance in D. insularis. The susceptible biotype absorbed at least 12% more (14)C-glyphosate up to 48 h after treatment (HAT) than resistant biotypes. High differential (14)C-glyphosate translocation was observed at 12 HAT, so that >70% of the absorbed herbicide remained in the treated leaf in resistant biotypes, whereas 42% remained in the susceptible biotype at 96 HAT. Glyphosate was degraded to aminomethylphosphonic acid (AMPA), glyoxylate, and sarcosine by >90% in resistant biotypes, whereas a small amount of herbicide (up to 11%) was degraded by the susceptible biotype up to 168 HAT. Two amino acid changes were found at positions 182 and 310 in EPSPS, consisting of a proline to threonine and a tyrosine to cysteine substitution, respectively, in resistant biotypes. Therefore, absorption, translocation, metabolism, and gene mutation play an important role in the D. insularis glyphosate resistance.

  19. Exposure assessment using human biomonitoring for glyphosate and fluroxypyr users in amenity horticulture.

    Science.gov (United States)

    Connolly, Alison; Jones, Kate; Galea, Karen S; Basinas, Ioannis; Kenny, Laura; McGowan, Padraic; Coggins, Marie

    2017-08-01

    Pesticides and their potential adverse health effects are of great concern and there is a dearth of knowledge regarding occupational exposure to pesticides among amenity horticulturalists. This study aims to measure occupational exposures to amenity horticuturalists using pesticides containing the active ingredients, glyphosate and fluroxypyr by urinary biomonitoring. A total of 40 work tasks involving glyphosate and fluroxypyr were surveyed over the period of June - October 2015. Workers used a variety of pesticide application methods; manual knapsack sprayers, controlled droplet applicators, pressurised lance applicators and boom sprayers. Pesticide concentrations were measured in urine samples collected pre and post work tasks using liquid chromatography tandem mass spectrometry (LC-MS/MS). Differences in pesticide urinary concentrations pre and post work task, and across applications methods were analysed using paired t-tests and linear regression. Pesticide urinary concentrations were higher than those reported for environmental exposures and comparable to those reported in some agricultural studies. Log-transformed pesticide concentrations were statistically significantly higher in post-work samples compared to those in pre-work samples (paired t-test, p<0.001; for both μgL(-1) and μmol/mol creatinine). Urinary pesticide concentrations in post-work samples had a geometric mean (geometric standard deviation) of 0.66 (1.11) μgL(-1) for glyphosate and 0.29 (1.69) μgL(-1) for fluroxypyr. Linear regression revealed a statistically significant positive association to exist between the time-interval between samples and the log-transformed adjusted (i.e. post- minus pre-task) pesticide urinary concentrations (β=0.0039; p<0.0001). Amenity horticulturists can be exposed to pesticides during tasks involving these products. Further research is required to evaluate routes of exposure among this occupational group. Crown Copyright © 2017. Published by Elsevier Gmb

  20. The effect of Saccharomyces cerevisiae on the stability of the herbicide glyphosate during bread leavening.

    Science.gov (United States)

    Low, F L; Shaw, I C; Gerrard, J A

    2005-01-01

    To investigate the ability of baker's yeast (Saccharomyces cerevisiae) to degrade the herbicide glyphosate during the fermentation cycle of the breadmaking process. Aqueous glyphosate was added to bread ingredients and kneaded by commercially available breadmaking equipment into dough cultures. Cultures were incubated in the breadmaker throughout the fermentation cycle. The recovery of glyphosate levels following fermentation was determined, thus allowing an estimation of glyphosate degradation by yeast. It was shown, for the first time, that S. cerevisiae plays a role in metabolizing glyphosate during the fermentation stages of breadmaking. Approximately 21% was degraded within 1 h. As a result of projected increases in the glyphosate use on wheat and the role of bread as a dietary staple, this may contribute to more informed decisions being made relating to the use of glyphosate on glyphosate-resistant wheat, from a public health/regulatory perspective.

  1. Loss of glyphosate efficacy: a changing weed spectrum in Georgia cotton

    Science.gov (United States)

    Introduction of glyphosate resistance into crops through genetic modification has revolutionized crop protection. Glyphosate, the proverbial silver bullet, is a broad spectrum herbicide with favorable environmental characteristics and effective broad-spectrum weed control that has greatly improved ...

  2. Alteration of plant physiology by glyphosate and its by-product aminomethylphosphonic acid: an overview.

    Science.gov (United States)

    Gomes, Marcelo P; Smedbol, Elise; Chalifour, Annie; Hénault-Ethier, Louise; Labrecque, Michel; Lepage, Laurent; Lucotte, Marc; Juneau, Philippe

    2014-09-01

    It is generally claimed that glyphosate kills undesired plants by affecting the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) enzyme, disturbing the shikimate pathway. However, the mechanisms leading to plant death may also be related to secondary or indirect effects of glyphosate on plant physiology. Moreover, some plants can metabolize glyphosate to aminomethylphosphonic acid (AMPA) or be exposed to AMPA from different environmental matrices. AMPA is a recognized phytotoxin, and its co-occurrence with glyphosate could modify the effects of glyphosate on plant physiology. The present review provides an overall picture of alterations of plant physiology caused by environmental exposure to glyphosate and its metabolite AMPA, and summarizes their effects on several physiological processes. It particularly focuses on photosynthesis, from photochemical events to C assimilation and translocation, as well as oxidative stress. The effects of glyphosate and AMPA on several plant physiological processes have been linked, with the aim of better understanding their phytotoxicity and glyphosate herbicidal effects.

  3. A Bayesian model for repeated measures zero-inflated count data with application to outpatient psychiatric service use

    Science.gov (United States)

    Neelon, Brian H.; O’Malley, A. James; Normand, Sharon-Lise T.

    2009-01-01

    In applications involving count data, it is common to encounter an excess number of zeros. In the study of outpatient service utilization, for example, the number of utilization days will take on integer values, with many subjects having no utilization (zero values). Mixed-distribution models, such as the zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB), are often used to fit such data. A more general class of mixture models, called hurdle models, can be used to model zero-deflation as well as zero-inflation. Several authors have proposed frequentist approaches to fitting zero-inflated models for repeated measures. We describe a practical Bayesian approach which incorporates prior information, has optimal small-sample properties, and allows for tractable inference. The approach can be easily implemented using standard Bayesian software. A study of psychiatric outpatient service use illustrates the methods. PMID:21339863

  4. Differential Effects of Glyphosate and Roundup on Human Placental Cells and Aromatase

    OpenAIRE

    Richard, Sophie; Moslemi, Safa; Sipahutar, Herbert; Benachour, Nora; Seralini, Gilles-Eric

    2005-01-01

    Roundup is a glyphosate-based herbicide used worldwide, including on most genetically modified plants that have been designed to tolerate it. Its residues may thus enter the food chain, and glyphosate is found as a contaminant in rivers. Some agricultural workers using glyphosate have pregnancy problems, but its mechanism of action in mammals is questioned. Here we show that glyphosate is toxic to human placental JEG3 cells within 18 hr with concentrations lower than those found with agricult...

  5. Glyphosate detection with ammonium nitrate and humic acids as potential interfering substances by pulsed voltammetry technique

    OpenAIRE

    MARTÍNEZ GIL, PABLO; Laguarda Miró, Nicolás; Soto Camino, Juan; Masot Peris, Rafael

    2013-01-01

    Pulsed voltammetry has been used to detect and quantify glyphosate on buffered water in presence of ammonium nitrate and humic substances. Glyphosate is the most widely used herbicide active ingredient in the world. It is a non-selective broad spectrum herbicide but some of its health and environmental effects are still being discussed. Nowadays, glyphosate pollution in water is being monitored but quantification techniques are slow and expensive. Glyphosate wastes are often detected in count...

  6. Degradation of the Phosphonate Herbicide Glyphosate by Arthrobacter atrocyaneus ATCC 13752

    OpenAIRE

    Pipke, Rüdiger; Amrhein, Nikolaus

    1988-01-01

    Of nine authentic Arthrobacter strains tested, only A. atrocyaneus ATCC 13752 was capable of using the herbicide glyphosate [N-(phosphonomethyl)glycine] as its sole source of phosphorus. Contrary to the previously isolated Arthrobacter sp. strain GLP-1, which degrades glyphosate via sarcosine, A. atrocyaneus metabolized glyphosate to aminomethylphosphonic acid. The carbon of aminomethylphosphonic acid was entirely converted to CO2. This is the first report on glyphosate degradation by a bacte...

  7. Levels of glyphosate in surface waters, sediments and soils associated with direct sowing soybean cultivation in north pampasic region of Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Peruzzo, Pablo J. [Grupo Materiales Polimericos, INIFTA - Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (UNLP-CONICET), Diag. 113 y 64, CC 16 Suc 4, 1900 La Plata (Argentina); Porta, Atilio A. [CIMA - Centro de Investigaciones del Medio Ambiente, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, 1900 La Plata (Argentina); Division Quimica Analitica, Departamento de Quimica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, 1900 La Plata (Argentina)], E-mail: aporta@quimica.unlp.edu.ar; Ronco, Alicia E. [CIMA - Centro de Investigaciones del Medio Ambiente, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, 1900 La Plata (Argentina)

    2008-11-15

    Levels of glyphosate were determined in water, soil and sediment samples from a transgenic soybean cultivation area located near to tributaries streams of the Pergamino-Arrecifes system in the north of the Province of Buenos Aires, Argentina. Field work took into account both the pesticide application and the rains occurring after applications. The pesticide was analysed by HPLC-UV detection, previous derivatization with 9-fluorenylmethylchloroformate (FMOC-Cl). In addition, SoilFug multimedia model was used to analyse the environmental distribution of the pesticides. In the field, levels of glyphosate in waters ranged from 0.10 to 0.70 mg/L, while in sediments and soils values were between 0.5 and 5.0 mg/Kg. Temporal variation of glyphosate levels depended directly on the time of application and the rain events. The results obtained from the application of the model are in accordance with the values found in the field. - Glyphosate concentrations in the environment from a region where little information exists about this and intensive cultivation activities predominate in large areas.

  8. Glyphosate resistance in giant ragweed (Ambrosia trifida L.) from Mississippi is partly due to reduced translocation

    Science.gov (United States)

    A giant ragweed population from a glyphosate-resistant (GR) soybean field in Mississippi was suspected to be resistant to glyphosate. Greenhouse and laboratory studies were conducted to confirm and quantify the magnitude of glyphosate resistance in the giant ragweed population and to elucidate the p...

  9. Mechanism Of Resistance Of Evolved Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri L.)

    Science.gov (United States)

    Evolved glyphosate resistance in weedy species represents a challenge for the continued success and utility of glyphosate-resistant crops. The first case of evolved glyphosate resistance in Palmer amaranth was a population from the U.S. state of Georgia, which was previously reported to have amplif...

  10. Utilization of glyphosate as phosphate source: biochemistry and genetics of bacterial carbon-phosphorous lyase

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne; Zechel, David L; Jochimsen, Bjarne

    2014-01-01

    After several decades of use of glyphosate, the active ingredient in weed killers such as Roundup, in fields, forests, and gardens, the biochemical pathway of transformation of glyphosate phosphorus to a useful phosphorus source for microorganisms has been disclosed. Glyphosate is a member of a l...

  11. Varying tolerance to glyphosate in a population of Palmer amaranth with low epsps copy number

    Science.gov (United States)

    A Palmer amaranth population (seeds collected in the year 2000; Washington Co., MS) suspected to be susceptible to glyphosate was examined as a population and as individual plants and found to exhibit varying tolerance or resistance to glyphosate. Whole plant spraying of glyphosate (0.84 kg ha-1) t...

  12. Effects of phosphate on the adsorption of glyphosate on three different types of Chinese soils

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-jun; ZHOU Dong-mei; SUN Rui-juan

    2005-01-01

    Glyphosate (GPS) is a non-selective, post-mergence herbicide that is widely used throughout the world. Due to the similar molecular structures of glyphosate and phosphate, adsorption of glyphosate on soil is easily affected by coexisting phosphate, especially when phosphate is applied at a significant rate in farmland. This paper studied the effects of phosphate on the adsorption of glyphosate on three different types of Chinese soils including two variable charge soils and one permanent charge soil. The results indicated that Freundlich equations used to simulate glyphosate adsorption isotherms gave high correlation coefficients(0.990-0.998) with K values of 2751, 2451 and 166 for the zhuanhong soil(ZH soil, Laterite), red soil(RS, Udic Ferrisol) and Wushan paddy soil(WS soil, Anthrosol),respectively. The more the soil iron and aluminum oxides and clay contained, the more glyphosate adsorbed. The presence of phosphate significantly decreased the adsorption of glyphosate to the soils by competing with glyphosate for adsorption sites of soils. Meanwhile, the effects of phosphate on adsorption of glyphosate on the two variable charge soils were more significant than that on the permanent charge soil. When phosphate and glyphosate were added in the soils in different orders, the adsorption quantities of glyphosate on the soils were different, which followed GPS-soil>GPS-P-soil = GPS-soil-P > P-soil-GPS, meaning a complex interaction occurred among glyphosate,phosphate and the soils.

  13. Presence of glyphosate and AMPA in orchard soils and water in the upper Río Negro and Neuquén valley

    Science.gov (United States)

    Holzmann, Rosa; Sheridan, Miguel; De Geronimo, Eduardo; Aparicio, Virginia; Costa, Jose Luis

    2017-04-01

    The Upper Valley of Río Negro and Neuquén provinces is the most important region of Argentina for pear and apple production. The local climate is arid, with deficits of plant available water of 1,200 mm per year with soils classified as Entisols and Aridisols. Flooding irrigation provides approximately 2,000 mm yearly. The weeds control consists on the application of glyphosate along the planting row 0.5 m each at both sides of the trees. The aim of this work was to detect the presence of glyphosate and AMPA (aminomethylphosphonic acid) remaining in water and soil. Some orchards were monitored one year after the herbicide application. Soil composed samples were taken at the 0 to 10 cm depth and also in the canals. Percolation water was taken from drainage canals until its final destination. Irrigation water before entering the orchards were also sampled. The presence of glyphosate and AMPA was detected in all samples. The soil in the canals had 1,098 and 340.5 µg.kg-1 of glyphosate and AMPA respectively. 934 and 1,864.5 µg.kg-1 of glyphosate and AMPA respectively on a land where the herbicide was recently applied; figures from 11 y 208µg.kg-1 (minimun) to 149.5 y 583 µg.kg-1 (maximum) of glyphosate and AMPA respectively in orchards on which the herbicide was applied one year before; finally, 13 and 17.5 µg.kg-1 minimun, and 32 and 30.5 µg.kg-1 maximun of glyphosate and AMPA respectively in draining channel sediments. As regards waters, and according to the quantity of molecules and the level allowed by the EU of 0.5 µg.l-1, the water source contained 0.56 µg.l-1, while, in the draining waters, we found concentrations between 1.5 and 12.21µg.l-1 right after soil percolation and between 0.49 and 5.0 µg.l-1 in secondary drainage canals and finally, between 0.5 and 1.4 µg.l-1 in the main canal. Glyphosate and AMPA comprised between 73% and 99.9% of the sum of total molecules in all cases.

  14. Acute toxicity and sublethal effects of the mixture glyphosate (Roundup Active) and Cosmo-Flux 411F to anuran embryos and tadpoles of four Colombian species.

    Science.gov (United States)

    Henao Muñoz, Liliana Marcela; Montes Rojas, Claudia Marsela; Bernal Bautista, Manuel Hernando

    2015-03-01

    Glyphosate is the most widely used herbicide in the world with application in agriculture, forestry, industrial weed control, garden and aquatic environments. However, its use is highly controversial for the possible impact on not-target organisms, such as amphibians, which are vanishing at an alarming and rapid rate. Due to the high solubility in water and ionic nature, the glyphosate requires of surfactants to increase activity. In addition, for the control of coca (Erythroxylum coca) and agricultural weeds in Colombia, formulated glyphosate is mixed and sprayed with the adjuvant Cosmo-Flux 411F to increase the penetration and activity of the herbicide. This study evaluates the acute toxic and sublethal effects (embryonic development, tadpole body size, tadpole swimming performance) of the mixture of the formulated glyphosate Roundup Active and Cosmo-Flux 411F to anuran embryos and tadpoles of four Colombian species under 96h laboratory standard tests and microcosms, which are more similar to field conditions as they include soil, sand and macrophytes. In the laboratory, embryos and tadpoles of Engystomops pustulosus were the most tolerant (LC50 = 3904 microg a.e./L; LC50=2 799 pg a.e./L, respectively), while embryos and tadpoles of Hypsiboas crepitans (LC50=2 203 microg a.e./L; LC50=1424 microgg a.e./L, respectively) were the most sensitive. R. humboldti and R. marina presented an intermediate toxicity. Embryos were significantly more tolerant to the mixture than tadpoles, which could be likely attributed to the exclusion of chemicals by the embryonic membranes and the lack of organs, such as gills, which are sensitive to surfactants. Sublethal effects were observed for the tadpole body size, but not for the embryonic development and tadpole swimming performance. In microcosms, no toxicity (LC50 could not be estimated), or sublethal responses were observed at concentrations up to fourfold (14.76 kg glyphosate a.e./ha) the highest field application rate of 3

  15. Sunscreens in human plasma and urine after repeated whole-body topical application

    DEFF Research Database (Denmark)

    Janjua, N.R.; Kongshoj, B.; Andersson, A.M.;

    2008-01-01

    Background The three chemical ultraviolet absorbers benzophenone-3 (BP-3), octyl-methoxycinnamate (OMC) and 3-(4-methylbenzylidene) camphor (4-MBC) are commercially used in sunscreens worldwide. Apart from sun protection, they may possess endocrine-disrupting effects in animals and in vitro...... the first application, all three sunscreens were detectable in plasma. The maximum median plasma concentrations were 187 ng/mL BP-3, 16 ng/mL 4-MBC and 7 ng/mL OMC for females and 238 ng/mL BP-3, 18 ng/mL 4-MBC and 16 ng/mL OMC for men. In the females, urine levels of 44 ng/mL BP-3 and 4 ng/mL of 4-MBC...... and 6 ng/mL OMC were found, and in the males, urine levels of 81 ng/mL BP-3, 4 ng/mL of 4-MBC and OMC were found. In plasma, the 96-h median concentrations were higher compared with the 24-h concentrations for 4-MBC and OMC in men and for BP-3 and 4-MBC in females Udgivelsesdato: 2008/4...

  16. 草甘膦对耐草甘膦大豆体内莽草酸含量及产量的影响%Shikimic Acid Accumulation as an Indicator of Glyphosate Tolerance in Glyphosate-Resistant Soybean

    Institute of Scientific and Technical Information of China (English)

    杨鑫浩; 李香菊

    2014-01-01

    采用网室盆栽试验与田间试验相结合的方法,测定处于不同叶龄的大豆在草甘膦处理后莽草酸的积累量。结果表明:1230~2460 g a.i./hm2草甘膦处理后,常规大豆莽草酸积累量急剧上升,并随草甘膦处理剂量的增加而升高。耐草甘膦大豆莽草酸积累量与不用药的空白对照差异不显著;在4920 g a.i./hm2草甘膦处理后,体内莽草酸出现短时间的积累,但5~9d后恢复至药前水平。在3、5、7张羽状三出复叶期喷施草甘膦后,不同叶龄之间的大豆叶片莽草酸积累量差异不显著,说明这3个叶龄处理的耐草甘膦大豆均有较好的耐受性。上述草甘膦处理剂量及处理时期施药后,耐草甘膦大豆籽粒产量与不用药的空白对照差异不显著。%Pot experiments and field trials were conducted to determine the shikimate accumulation after glyphosate appli -cation during the period of soybean growth .At 1 230.0~2 460.0 g a.i./hm2,shikimate accumulation rapidly increased in leaves of conventional soybean .Accumulation increased with increasing herbicide doses .Shikimate accumulation in glyphosate-resistant soybean did not differ between glyphosate -applied and blank control treatments .Shikimate accu-mulation did not differ among glyphosate -resistant crop plants treated with glyphostate at the 3 -,5 -and 7 -leaf growth stages,which indicates that transgenic soybeans at those growth stages expressed high tolerance to glyphosate .At 4 920 g a.i./hm2 ,shikimate transiently accumulated but returned to its normal level before the glyphosate application after 5~9 days.The transgenic glyphosate -resistant soybean subjected to the above dosage of glyphosate produced the same yield as the blank control .Shikimate accumulation can be used as an early detection index of glyphosate tolerance levels of soybean .

  17. Degradation of glyphosate and other pesticides by ligninolytic enzymes.

    Science.gov (United States)

    Pizzul, Leticia; Castillo, María del Pilar; Stenström, John

    2009-11-01

    The ability of pure manganese peroxidase (MnP), laccase, lignin peroxidase (LiP) and horseradish peroxidase (HRP) to degrade the widely used herbicide glyphosate and other pesticides was studied in separate in vitro assays with addition of different mediators. Complete degradation of glyphosate was obtained with MnP, MnSO4 and Tween 80, with or without H2O2. In the presence of MnSO4, with or without H(2)O(2), MnP also transformed the herbicide, but to a lower rate. Laccase degraded glyphosate in the presence of (a) 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), (b) MnSO(4) and Tween 80 and (c) ABTS, MnSO4 and Tween 80. The metabolite AMPA was detected in all cases where degradation of glyphosate occurred and was not degraded. The LiP was tested alone or with MnSO4, Tween 80, veratryl alcohol or H2O2 and in the HRP assay the enzyme was added alone or with H2O2 in the reaction mixture. However, these enzymes did not degrade glyphosate. Further experiments using MnP together with MnSO4 and Tween 80 showed that the enzyme was also able to degrade glyphosate in its commercial formulation Roundup Bio. The same enzyme mixture was tested for degradation of 22 other pesticides and degradation products present in a mixture and all the compounds were transformed, with degradation percentages ranging between 20 and 100%. Our results highlight the potential of ligninolytic enzymes to degrade pesticides. Moreover, they suggest that the formation of AMPA, the main metabolite of glyphosate degradation found in soils, can be a result of the activity of lignin-degrading enzymes.

  18. Degradation and Isotope Source Tracking of Glyphosate and Aminomethylphosphonic Acid.

    Science.gov (United States)

    Li, Hui; Joshi, Sunendra R; Jaisi, Deb P

    2016-01-27

    Glyphosate [N-(phosphonomethyl) glycine], an active ingredient of the herbicide Roundup, and its main metabolite, aminomethylphosphonic acid (AMPA), have been frequently reported to be present in soils and other environments and thus have heightened public concerns on their potential adverse effects. Understanding the fate of these compounds and differentiating them from other naturally occurring compounds require a toolbox of methods that can go beyond conventional methods. Here, we applied individual isotope labeling technique whereby each compound or mineral involved in the glyphosate and AMPA degradation reaction was either synthesized or chosen to have distinct (18)O/(16)O ratios so that the source of incorporated oxygen in the orthophosphate generated and corresponding isotope effect during C-P bond cleavage could be identified. Furthermore, we measured original isotope signatures of a few commercial glyphosate sources to identify their source-specific isotope signatures. Our degradation kinetics results showed that the rate of glyphosate degradation was higher than that of AMPA in all experimental conditions, and both the rate and extent of degradation were lowest under anoxic conditions. Oxygen isotope ratios (δ(18)OP) of orthophosphate generated from glyphosate and AMPA degradation suggested that one external oxygen atom from ambient water, not from dissolved oxygen or mineral, was incorporated into orthophosphate with the other three oxygen atoms inherited from the parent molecule. Interestingly, δ(18)OP values of all commercial glyphosate products studied were found to be the lightest among all orthophosphates known so far. Furthermore, isotope composition was found to be unaffected due to variable degradation kinetics, light/dark, and oxic/anoxic conditions. These results highlight the importance of phosphate oxygen isotope ratios as a nonconventional tool to potentially distinguish glyphosate sources and products from other organophosphorus compounds

  19. The clinical applicability of a daily summary of patients' self-reported postoperative pain-A repeated measure analysis.

    Science.gov (United States)

    Wikström, Lotta; Eriksson, Kerstin; Fridlund, Bengt; Nilsson, Mats; Årestedt, Kristofer; Broström, Anders

    2017-03-23

    (i) To determine whether a central tendency, median, based on patients' self-rated pain is a clinically applicable daily measure to show patients' postoperative pain on the first day after major surgery (ii) and to determine the number of self-ratings required for the calculation of this measure. Perioperative pain traits in medical records are difficult to overview. The clinical applicability of a daily documented summarising measure of patients' self-rated pain scores is little explored. A repeated measure design was carried out at three Swedish country hospitals. Associations between the measures were analysed with nonparametric statistical methods; systematic and individual group changes were analysed separately. Measure I: pain scores at rest and activity postoperative day 1; measure II: retrospective average pain from postoperative day 1. The sample consisted of 190 general surgery patients and 289 orthopaedic surgery patients with a mean age of 65; 56% were men. Forty-four percent had a pre-operative daily intake of analgesia, and 77% used postoperative opioids. A range of 4-9 pain scores seem to be eligible for the calculation of the daily measures of pain. Rank correlations for individual median scores, based on four ratings, vs. retrospective self-rated average pain, were moderate and strengthened with increased numbers of ratings. A systematic group change towards a higher level of reported retrospective pain was significant. The median values were clinically applicable daily measures. The risk of obtaining a higher value than was recalled by patients seemed to be low. Applicability increased with increased frequency of self-rated pain scores and with high-quality pain assessments. The documenting of daily median pain scores at rest and during activity could constitute the basis for obtaining patients' experiences by showing their pain severity trajectories. The measures could also be an important key to predicting postoperative health

  20. Práticas de manejo e a resistência de Euphorbia heterophylla aos inibidores da ALS e tolerância ao glyphosate no Rio Grande do Sul Management practices x Euphorbia heterophylla resistance to ALS-inhibitors and tolerance to glyphosate in Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    L. Vargas

    2013-06-01

    herbicide resistant biotypes also in acetolactate synthase (ALS-inhibitors. Thus, the objectives of this work were to evaluate wild poinsettia's sensitivity to the ALS-inhibiting herbicides and glyphosate; to investigate the distribution of resistant biotypes in the state of RS;and to determine the main agronomic factors associated with control failures. Seeds of wild poinsettia plants that survived glyphosate applications were collected from RR soybean fields located in 56 municipalities in the state of RS. On the occasion, the farmers were interviewed through a questionnaire aiming to collect information on the management of the area. Using the seeds collected, two experiments were conducted under greenhouse conditions. The first evaluated the response of 86 biotypes to glyphosate, applied at the rate of 2.160 g ha-1 while the second experiment evaluated the response of the herbicide imazethapyr to 73 biotypes, applied at a dose of 200 g a.i. ha‑1. The results show that all the wild poinsettia biotypes evaluated are susceptible to glyphosate, but some are resistant to ALS-inhibitors. The survey responses indicate that management practices such as the use of sub doses and/or intensive use of glyphosate, as well as lack of crop rotation favor failures in wild poinsettia control by glyphosate in soybean.

  1. Application of a Reinforced Self-Compacting Concrete Jacket in Damaged Reinforced Concrete Beams under Monotonic and Repeated Loading

    Directory of Open Access Journals (Sweden)

    Constantin E. Chalioris

    2013-01-01

    Full Text Available This paper presents the findings of an experimental study on the application of a reinforced self-compacting concrete jacketing technique in damaged reinforced concrete beams. Test results of 12 specimens subjected to monotonic loading up to failure or under repeated loading steps prior to total failure are included. First, 6 beams were designed to be shear dominated, constructed by commonly used concrete, were initially tested, damaged, and failed in a brittle manner. Afterwards, the shear-damaged beams were retrofitted using a self-compacting concrete U-formed jacket that consisted of small diameter steel bars and U-formed stirrups in order to increase their shear resistance and potentially to alter their initially observed shear response to a more ductile one. The jacketed beams were retested under the same loading. Test results indicated that the application of reinforced self-compacting concrete jacketing in damaged reinforced concrete beams is a promising rehabilitation technique. All the jacketed beams showed enhanced overall structural response and 35% to 50% increased load bearing capacities. The ultimate shear load of the jacketed beams varied from 39.7 to 42.0 kN, whereas the capacity of the original beams was approximately 30% lower. Further, all the retrofitted specimens exhibited typical flexural response with high values of deflection ductility.

  2. Effect of Am-80, A Novel Retinoid Derivative, On Contact Hypersensitivity Caused by Repeated Applications of Hapten in Mice

    Directory of Open Access Journals (Sweden)

    Satoru Niwa

    2000-01-01

    Full Text Available Some retinoids show an anti-inflammatory action through regulation of transcription of various genes. In the present study, the inhibitory effect of 4-((5,6,7,8- tetrahydro-5,5,8,8-tetramethyl-2-naphthyl carbamoyl benzoic acid (Am-80, a synthetic retinoid, on mouse contact hypersensitivity provoked by repeated applications of 2,4-dinitrofluorobenzene (DNFB to the ear was investigated. Five-fold applications of DNFB on ears once per week elicited severe contact dermatitis with marked infiltration of inflammatory cells and elevation of anti-dinitrophenyl (DNP-IgE antibody in the serum. The Am-80 significantly inhibited ear swelling in a dose-dependent manner. In the histopathologic study, infiltration of inflammatory cells was clearly decreased by Am-80. However, Am-80 did not affect the production of DNP-specific IgE antibody both at the transcriptional and post-transcriptional levels. The effects of Am-80 on the transcriptional level of cytokines, interferon (IFN-γ, interleukin (IL-1 and IL-4 in cervical lymph nodes were investigated. Marked elevation of mRNA for all cytokines was observed and Am-80 potently inhibited the expression of IFN-γ mRNA, but not IL-1 and IL-4 mRNA. These findings indicated that Am-80 may inhibit the contact dermatitis at the post-sensitization phase by inhibiting IFN-γ production at the transcriptional level in mice.

  3. Effect of fertilization in interaction with glyphosate on the availability of phosphorus in rice soils of Corrientes - Argentina

    Science.gov (United States)

    Micaela biassoni, Maria; Rey Montoya, Tania; Herber, Luciana; De Geronimo, Eduardo; Aparicio, Virginia

    2017-04-01

    The rice crop (Oryza sativa) in the province of Corrientes, Argentina, represents 46% of the national production. To obtain potential yields, adequate practices of fertilization, pesticides application, and management of the irrigation system are needed. Nitrogen (N), phosphorus (P) and potassium (K) are key minerals in rice production. In Argentina, P deficiency is a common problem in rice crops and represents a main yield limiting factor, therefore P fertilization is a regular practice. On the other hand, glyphosate is widely used to control weeds. This molecule is rapidly inactivated in soil due to the adsorption to clay particles and organic matter, however, is excluded from adsorption sites by inorganic phosphates. Meanwhile, both practices of fertilization and herbicide application can interact and influence the phosphate nutrition of rice plants. The objective of this work was to evaluate the effect of different doses of fertilizer in interaction with glyphosate on the availability of soil phosphorus. A field experiment following a completely randomized design was carried out with four replicates. We evaluated four levels of fertilization (0-18-40): Control: 0 kg ha-1, Dose 1: 120 kg ha-1, Dose 2: 150 kg ha-1, Dose 3: 180 kg ha-1; and two levels of Glyphosate: with (Gly) or without (no-Gly) application. Soil sampling was carried out at three moments along crop season: vegetative stage before irrigation (V4), in floral primordial differentiation (DPF) with flooded soil, and at physiological maturity (MF). The method used for the determination of P was Bray & Kurtz I. We found a negative relation and non-significant interaction (p glyphosate for adsorption sites and they were available in soil solution while herbicide molecules were retained by colloidal particles.

  4. Control of yellow and purple nutsedge in elevated CO2 environments with glyphosate and halosulfuron

    Directory of Open Access Journals (Sweden)

    Stephen Christopher Marble

    2015-01-01

    Full Text Available Atmospheric concentrations of carbon dioxide (CO2 have significantly increased over the past century and are expected to continue rising in the future. While elevated levels of CO2 will likely result in higher crop yields, weed growth is also highly likely to increase, which could increase the incidence of herbicide resistant biotypes. An experiment was conducted in 2012 to determine the effects of an elevated CO2 environment on glyphosate and halosulfuron efficacy for postemergence control of purple and yellow nutsedge (Cyperus rotundus L. and C. esculentus L.. Both species of nutsedge where grown in 3.0-L containers under either ambient or elevated (ambient + 200 µmol mol-1 CO2 in open-top field chambers and treated with either 0.5×, 1.0×, or 1.5× of the manufacturer’s labeled rate of halosulfuron, glyphosate, or a tank mix of the two herbicides. The growth of both nutsedge species responded positively to elevated CO2, purple nutsedge had increased shoot and root dry weights and yellow nutsedge had increased shoot, root, and tuber dry weights and counts. Few treatment differences were observed among the herbicides at any of the rates tested. At three weeks following herbicide application, both purple and yellow nutsedge were adequately controlled by both herbicides and combinations at all rates tested, regardless of CO2 concentration. Based on this study, it is likely that predicted future CO2 levels will have little impact on the efficacy of single applications of halosulfuron or glyphosate for control of purple and yellow nutsedge at the growth stages described here, although scenarios demanding more persistent control efforts remain a question.

  5. Control of yellow and purple nutsedge in elevated CO2 environments with glyphosate and halosulfuron.

    Science.gov (United States)

    Marble, S Christopher; Prior, Stephen A; Runion, G Brett; Torbert, H Allen

    2015-01-01

    Atmospheric concentrations of carbon dioxide (CO2) have significantly increased over the past century and are expected to continue rising in the future. While elevated levels of CO2 will likely result in higher crop yields, weed growth is also highly likely to increase, which could increase the incidence of herbicide resistant biotypes. An experiment was conducted in 2012 to determine the effects of an elevated CO2 environment on glyphosate and halosulfuron efficacy for postemergence control of purple and yellow nutsedge (Cyperus rotundus L. and C. esculentus L.). Both species of nutsedge where grown in 3.0-L containers under either ambient or elevated (ambient + 200 μmol mol(-1)) CO2 in open-top field chambers and treated with either 0.5×, 1.0×, or 1.5× of the manufacturer's labeled rate of halosulfuron, glyphosate, or a tank mix of the two herbicides. The growth of both nutsedge species responded positively to elevated CO2, purple nutsedge had increased shoot and root dry weights and yellow nutsedge had increased shoot, root, and tuber dry weights and counts. Few treatment differences were observed among the herbicides at any of the rates tested. At 3 weeks following herbicide application, both purple and yellow nutsedge were adequately controlled by both herbicides and combinations at all rates tested, regardless of CO2 concentration. Based on this study, it is likely that predicted future CO2 levels will have little impact on the efficacy of single applications of halosulfuron or glyphosate for control of purple and yellow nutsedge at the growth stages described here, although scenarios demanding more persistent control efforts remain a question.

  6. Exposure of juvenile green frogs (Lithobates clamitans) in littoral enclosures to a glyphosate-based herbicide.

    Science.gov (United States)

    Edge, Christopher B; Gahl, Megan K; Pauli, Bruce D; Thompson, Dean G; Houlahan, Jeff E

    2011-07-01

    The majority of studies on the toxicity of glyphosate-based herbicides to amphibians have focused on larval life stages exposed in aqueous media. However, adult and juvenile amphibians may also be exposed directly or indirectly to herbicides. The potential for such exposures is of particular interest in the littoral zone surrounding wetlands as this is preferred habitat for many amphibian species. Moreover, it may be argued that potential herbicide effects on juvenile or adult amphibians could have comparatively greater influence on overall recruitment, reproductive potential and thus stability of local populations than effects on larvae. In this experiment, juvenile green frogs (Lithobates clamitans) were exposed to two concentrations (2.16 and 4.27 kg a.e./ha) of a glyphosate-based herbicide formulation (VisionMax®), which were based on typical application scenarios in Canadian forestry. The experimental design employed frogs inhabiting in situ enclosures established at the edge of small naturalized wetlands that were split in half using an impermeable plastic barrier. When analyzed using nominal target application rates, exposure to the glyphosate-based herbicide had no significant effect on survival, body condition, liver somatic index or the observed rate of Batrachochytrium dendrobatidis infection. However, there were marginal trends in both ANOVA analysis and post-hoc regressions regarding B. dendrobatidis infection rates and liver somatic index in relation to measured exposure estimates. Results from this study highlight the importance of field research and the need to include multiple endpoints when examining potential effects of a contaminant on non-target organisms. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Efeito do período de chuva no controle de Euphorbia heterophylla e Ipomoea purpurea pelos herbicidas glyphosate e sulfosate Effect of rainfall on Euphorbia heterophylla and Ipomoea purpurea control by glyphosate and sulfosate

    Directory of Open Access Journals (Sweden)

    P.A. Monquero

    2007-01-01

    1.44 kg ha-1 submitted to rainfall simulation of 20 mm for 30 minutes, 2, 4, 6, 8, and 48 h after application. The experimental design was completely randomized with four replicates. Weed control efficacy was evaluated 7, 14, and 21 d after treatments (DAT and dry biomass was evaluated 28 DAT. E. heterophylla was not efficiently controlled by glyphosate, demanding rainfall interval longer than 24 h after application to attain a moderate control of 60% when the highest rate was applied. On the other hand, sulfosate provided control of 75% when rainfall occurred just 4 h after application. I. purpurea was not controlled by glyphosate, either Sulfosate was only effective in controlling this species at the highest application rate, without rainfall. For both species, sulfosate was less affected by rainfall occurrence.

  8. Effect of repeated application of fenthion as a mosquito larvicide on Nile tilapia (Oreochromis niloticus) inhabiting selected water canals in Sri Lanka.

    Science.gov (United States)

    Jayasundara, Viranga K; Pathiratne, Asoka

    2008-04-01

    Health status of feral Nile tilapia following repeated applications of fenthion as a mosquito larvicide to selected water canals in Sri Lanka was assessed. With three spray applications of fenthion to the study sites at weekly intervals at the concentration recommended for mosquito control, condition factor and brain acetylcholinesterase activity of the fish were depressed in a time dependent manner. Prominent histopathological alterations displayed were gill hyperplasia and telangiectasis and vacoulation of hepatocytes. Observed ill health effects of fenthion on the fish demonstrate probable ecological risk to the fish populations inhabiting the water canals which receive repeated inputs of fenthion.

  9. The effect of glyphosate and nitrogen on plant communities and the soil fauna in terrestrial biotopes at field margins

    DEFF Research Database (Denmark)

    Damgaard, Christian; Strandberg, Beate; Dupont, Yoko

    that are known to affect plant communities may affect pollination and the soil fauna. The combined use of plant trait and soil fauna trait data in a full-factorial field experiment of glyphosate and nitrogen has never been explored before. The focus on plant and soil fauna traits rather than species enabled...... a robust description of the ecological processes at the functional level. More specifically, both fertilizers and herbicides affected species composition. Generally, species cover decreased with increasing glyphosate doses, although cover of Festuca ovina and Euphorbia esula forms exceptions. Increasing...... an increase in Grimes S. For the two composite species Tanacetum vulgare and Leucanthemum vulgare, the two most heavily affected traits were floral density and flowering phenology, in turn leading to marked changes in plant-pollinator interactions. Nitrogen application caused a shift towards earthworms...

  10. Efeitos do glyphosate e sulfometuron-methyl no crescimento e na qualidade tecnológica da cana-de-açúcar Effect of glyphosate and sulfometuron-methyl on the growth and technological quality of sugarcane

    Directory of Open Access Journals (Sweden)

    D.K. Meschede

    2010-01-01

    the plant, leading to qualitative and quantitative changes in production. This study aimed to evaluate the agronomic efficiency and the effects during sugarcane ratoon growth after applying low doses of glyphosate and sulfometuron-methyl. The experiment was arranged in a randomized block design with four replications. The treatments consisted of application of two herbicides (glyphosate and sulfometuron-methyl at various doses and mixtures and a control (without herbicide application. One row of plants was used to measure technological quality, with a random 1 m being established for each sampling time. The stems collected were submitted to apical bud emergence and defoliation and were sent to be processed according to the methodology of the Cane Payment System based on Sucrose Content (CPSSC, considering the following technological parameters: pol cane (PCC, broth purity (BP, total recoverable sugar (TRS, and Brix. The stumps were analyzed for sugarcane growth (height and tillers. Evaluations were performed during pre-harvest (30 DAA, 30, 60, 90, 120, 150 and 180 days after harvest. The treatments with glyphosate and sulfometuron-methyl provided improved technological quality of the raw material, with significant increases in broth purity and Brix. Herbicide application did not affect productivity and sugar content. There was a stimulating effect on tillering with glyphosate at a dose of 400 mL, and growth reduction (height at the start of cane development, but such effect was not maintained along time.

  11. 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.

  12. 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.

  13. Toxic effects of glyphosate on diploid and triploid fin cell lines from Misgurnus anguillicaudatus.

    Science.gov (United States)

    Qin, Yanjie; Li, Xia; Xiang, Yang; Wu, Di; Bai, Liwen; Li, Zhuangzhuang; Liang, Yan

    2017-08-01

    We examined the toxic effects of glyphosate on diploid (DIMF) and triploid (TRMF) fin cell lines from the Oriental Weather Loach Misgurnus anguillicaudatus. The LC50 values of glyphosate estimated by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay were 315.34 and 371.77 mg/L for DIMF and TRMF, respectively. Superoxide dismutase (SOD) and glutathione-S-transferase (GST) activities in DIMF and TRMF cells gradually increased and then decreased with increasing glyphosate concentrations, reaching a maximum at 240 mg/L glyphosate. In contrast, acetylcholinesterase (AChE) activities in DIMF and TRMF decreased with increasing concentrations of glyphosate in a concentration-dependent manner. SOD and AChE activities were generally significantly higher in TRMF compared with DIMF cells (P glyphosate compared with the control groups (P glyphosate. There were no differences in the rates of micronuclei and abnormal nuclei between DIMF and TRMF cells at any glyphosate concentration. Cell damage, including chromatin condensation, nucleus distortion, and broken and reduced endoplasmic reticulum, mitochondria, and ribosomes, were found in both cells treated with the LC50 concentration of glyphosate. Moreover, vacuolization and apoptotic bodies occurred in glyphosate-exposed DIMF and TRMF cells, indicating apoptosis. These results indicate that glyphosate in the range of tested concentrations represent a potential risk to loach through inhibiting proliferation of diploid and triploid cell lines and induces micronuclei and apoptosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Comparative proteomic analysis of horseweed (Conyza canadensis) biotypes identifies candidate proteins for glyphosate resistance.

    Science.gov (United States)

    González-Torralva, Fidel; Brown, Adrian P; Chivasa, Stephen

    2017-02-15

    Emergence of glyphosate-resistant horseweed (Conyza canadensis) biotypes is an example of how unrelenting use of a single mode of action herbicide in agricultural weed control drives genetic adaptation in targeted species. While in other weeds glyphosate resistance arose from target site mutation or target gene amplification, the resistance mechanism in horseweed uses neither of these, being instead linked to reduced herbicide uptake and/or translocation. The molecular components underpinning horseweed glyphosate-resistance remain unknown. Here, we used an in vitro leaf disc system for comparative analysis of proteins extracted from control and glyphosate-treated tissues of glyphosate-resistant and glyphosate-susceptible biotypes. Analysis of shikimic acid accumulation, ABC-transporter gene expression, and cell death were used to select a suitable glyphosate concentration and sampling time for enriching proteins pivotal to glyphosate resistance. Protein gel analysis and mass spectrometry identified mainly chloroplast proteins differentially expressed between the biotypes before and after glyphosate treatment. Chloroplasts are the organelles in which the shikimate pathway, which is targeted by glyphosate, is located. Calvin cycle enzymes and proteins of unknown function were among the proteins identified. Our study provides candidate proteins that could be pivotal in engendering resistance and implicates chloroplasts as the primary sites driving glyphosate-resistance in horseweed.

  15. No fitness cost of glyphosate resistance endowed by massive EPSPS gene amplification in Amaranthus palmeri.

    Science.gov (United States)

    Vila-Aiub, Martin M; Goh, Sou S; Gaines, Todd A; Han, Heping; Busi, Roberto; Yu, Qin; Powles, Stephen B

    2014-04-01

    Amplification of the EPSPS gene has been previously identified as the glyphosate resistance mechanism in many populations of Amaranthus palmeri, a major weed pest in US agriculture. Here, we evaluate the effects of EPSPS gene amplification on both the level of glyphosate resistance and fitness cost of resistance. A. palmeri individuals resistant to glyphosate by expressing a wide range of EPSPS gene copy numbers were evaluated under competitive conditions in the presence or absence of glyphosate. Survival rates to glyphosate and fitness traits of plants under intra-specific competition were assessed. Plants with higher amplification of the EPSPS gene (53-fold) showed high levels of glyphosate resistance, whereas less amplification of the EPSPS gene (21-fold) endowed a lower level of glyphosate resistance. Without glyphosate but under competitive conditions, plants exhibiting up to 76-fold EPSPS gene amplification exhibited similar height, and biomass allocation to vegetative and reproductive organs, compared to glyphosate susceptible A. palmeri plants with no amplification of the EPSPS gene. Both the additive effects of EPSPS gene amplification on the level of glyphosate resistance and the lack of associated fitness costs are key factors contributing to EPSPS gene amplification as a widespread and important glyphosate resistance mechanism likely to become much more evident in weed plant species.

  16. Bacterial glyphosate resistance conferred by overexpression of an E. coli membrane efflux transporter.

    Science.gov (United States)

    Staub, Jeffrey M; Brand, Leslie; Tran, Minhtien; Kong, Yifei; Rogers, Stephen G

    2012-04-01

    Glyphosate herbicide-resistant crop plants, introduced commercially in 1994, now represent approximately 85% of the land area devoted to transgenic crops. Herbicide resistance in commercial glyphosate-resistant crops is due to expression of a variant form of a bacterial 5-enolpyruvylshikimate-3-phosphate synthase with a significantly decreased binding affinity for glyphosate at the target site of the enzyme. As a result of widespread and recurrent glyphosate use, often as the only herbicide used for weed management, increasing numbers of weedy species have evolved resistance to glyphosate. Weed resistance is most often due to changes in herbicide translocation patterns, presumed to be through the activity of an as yet unidentified membrane transporter in plants. To provide insight into glyphosate resistance mechanisms and identify a potential glyphosate transporter, we screened Escherichia coli genomic DNA for alternate sources of glyphosate resistance genes. Our search identified a single non-target gene that, when overexpressed in E. coli and Pseudomonas, confers high-level glyphosate resistance. The gene, yhhS, encodes a predicted membrane transporter of the major facilitator superfamily involved in drug efflux. We report here that an alternative mode of glyphosate resistance in E. coli is due to reduced accumulation of glyphosate in cells that overexpress this membrane transporter and discuss the implications for potential alternative resistance mechanisms in other organisms such as plants.

  17. Comparative proteomic analysis of horseweed (Conyza canadensis) biotypes identifies candidate proteins for glyphosate resistance

    Science.gov (United States)

    González-Torralva, Fidel; Brown, Adrian P.; Chivasa, Stephen

    2017-01-01

    Emergence of glyphosate-resistant horseweed (Conyza canadensis) biotypes is an example of how unrelenting use of a single mode of action herbicide in agricultural weed control drives genetic adaptation in targeted species. While in other weeds glyphosate resistance arose from target site mutation or target gene amplification, the resistance mechanism in horseweed uses neither of these, being instead linked to reduced herbicide uptake and/or translocation. The molecular components underpinning horseweed glyphosate-resistance remain unknown. Here, we used an in vitro leaf disc system for comparative analysis of proteins extracted from control and glyphosate-treated tissues of glyphosate-resistant and glyphosate-susceptible biotypes. Analysis of shikimic acid accumulation, ABC-transporter gene expression, and cell death were used to select a suitable glyphosate concentration and sampling time for enriching proteins pivotal to glyphosate resistance. Protein gel analysis and mass spectrometry identified mainly chloroplast proteins differentially expressed between the biotypes before and after glyphosate treatment. Chloroplasts are the organelles in which the shikimate pathway, which is targeted by glyphosate, is located. Calvin cycle enzymes and proteins of unknown function were among the proteins identified. Our study provides candidate proteins that could be pivotal in engendering resistance and implicates chloroplasts as the primary sites driving glyphosate-resistance in horseweed. PMID:28198407

  18. Glyphosate biodegradation and potential soil bioremediation by Bacillus subtilis strain Bs-15.

    Science.gov (United States)

    Yu, X M; Yu, T; Yin, G H; Dong, Q L; An, M; Wang, H R; Ai, C X

    2015-11-23

    Glyphosate and glyphosate-containing herbicides have an adverse effect on mammals, humans, and soil microbial ecosystems. Therefore, it is important to develop methods for enhancing glyphosate degradation in soil through bioremediation. We investigated the potential of glyphosate degradation and bioremediation in soil by Bacillus subtilis Bs-15. Bs-15 grew well at high concentrations of glyphosate; the maximum concentration tolerated by Bs-15 reached 40,000 mg/L. The optimal conditions for bacterial growth and glyphosate degradation were less than 10,000 mg/L glyphosate, with a temperature of 35°C and a pH of 8.0. Optimal fermentation occurred at 180 rpm for 60 h with an inoculum ratio of 4%. Bs-15 degraded 17.65% (12 h) to 66.97% (96 h) of glyphosate in sterile soil and 19.01% (12 h) to 71.57% (96 h) in unsterilized soil. Using a BIOLOG ECO plate test, we observed no significant difference in average well color development values between the soil inoculated with Bs-15 and the control soil before 72 h, although there was a significant difference (P glyphosate-containing herbicides, increasing the microbial functional diversity in glyphosate-contaminated soils and thus enhancing the bioremediation of glyphosate-contaminated soils.

  19. Efeito do glyphosate sobre a morfoanatomia das folhas e do caule de Commelina diffusa e C. benghalensis Effect of glyphosate on the morpho-anatomy of leaves and stems of C. diffusa and C. benghalensis

    Directory of Open Access Journals (Sweden)

    L.D. Tuffi Santos

    2004-03-01

    in larger tolerance to glyphosate of C. diffusa in relation to C. benghalensis. From 10 pots for each species, 9 were applied with 1440 g ha-1 of glyphosate and one was used as check. Fragments of stems and leaves were collected and fixed at time zero (before the application of glyphosate, 15, 30, and 50 days after the application (DAA. The histological slides were obtained according to the usual methodology, with emphasis to the application of the lugol reagent to check starch. Grades from 1 to 5 were given according to the growing intensity of the reaction. In leaves, the epidermal cells and the vascular tissues are just a little bit affected. How seer the mesophyll is completely disorganized, resulting in cell death. Injures are more obvious stems and leaves of C. benghalensis. Morphologically, clorotic regions and deceased spots all over the leaf surface lead to leaf fall after 15° DAA in C. benghalensis. In C. diffusa, the leaf abscission is delayed, despite the injuries are almost the same. Both species presented higher quantities of starch in the node region than the internode. C. benghalensis has few and small starch grains, compared to many and big grains in C. diffusa. In response to glyphosate application , there was a variation in the number of starch grains in the stem to the time after the application. C. diffusa will always have larger possibilities to recover after glyphosate application because of its larger reservation of starch.

  20. Uses of glyphosate in German arable farming – aspects of weed management and arable practice

    Directory of Open Access Journals (Sweden)

    Wiese, Armin

    2016-02-01

    Full Text Available Data on glyphosate use, personal attitudes and farm characteristics were collected in a Germany-wide inventory from 2026 farms. About 1700 farms could be analyzed in detail. Categories of glyphosate users were split into: non-users, low proportion users and high proportion users. The latter apply glyphosate on > 20% of their arable land are characterized by a high amount of non-inversion tillage, low labor effort and aboveaverage farm size. Perennial weeds play a less important role for glyphosate use than managing weed populations that are regarded as less susceptible to regular herbicides. Non-users and users of glyphosate differ in their attitude towards the benefits of glyphosate and the amount of glyphosate use in agriculture.

  1. Selectivity of glyphosate tank mixtures for RR soybean Seletividade de glyphosate em misturas em tanque para soja RR

    Directory of Open Access Journals (Sweden)

    D.G Alonso

    2011-12-01

    Full Text Available An active ingredients mixture of different action mechanisms is an essential tool to prevent or manage areas with resistant weeds. However, it is important that such a mixture provides adequate selectivity to the crop. The aim of this work was to evaluate glyphosate selectivity to glyphosate-resistant (RR soybean, and also verify if there is selectivity in mixtures with other active ingredients applied postemergence aimed at new control strategies, which might be used in RR soybean cultivation. The herbicides and respective rates (g ha-1 evaluated were: glyphosate (720, 960, 1,200, and 1,440, and the mixtures of glyphosate (960 with cloransulam-methyl (30.24, fomesafen (125, lactofen (72, chlorimuron-ethyl (12.5, flumiclorac-pentyl (30, bentazon (480, or imazethapyr (80. All treatments were applied in postemergence when the soybean crop was at V2 to V3 stage. Treatments with glyphosate or in mixtures with postemergent herbicides showed visual effects of phytotoxicity when applied to the glyphosate-resistant soybean. Effects such as reduction in plant height, crop closure, number of pods per plant, and hundred grain weight could be observed. However, the effects related to plant development were mostly transient and did not persist during the crop cycle. Among the studied treatments, only the mixture of glyphosate and lactofen was not selective to the crop, promoting negative effects on most characteristics analyzed and consequently reducing grain yield.A mistura de ingredientes ativos de diferentes mecanismos de ação é uma ferramenta essencial para prevenir ou manejar áreas com plantas daninhas resistentes. No entanto é importante que tais associações forneçam adequada seletividade para a cultura. O objetivo deste trabalho foi avaliar a seletividade do glyphosate a soja RR, e verificar também, se existe seletividade a misturas com outros ingredientes ativos, aplicados em pós-emergência, visando novas estratégias de controle que poder

  2. Direct and indirect effects of the glyphosate formulation Glifosato Atanor® on freshwater microbial communities.

    Science.gov (United States)

    Vera, María Solange; Di Fiori, Eugenia; Lagomarsino, Leonardo; Sinistro, Rodrigo; Escaray, Roberto; Iummato, María Mercedes; Juárez, Angela; Ríos de Molina, María del Carmen; Tell, Guillermo; Pizarro, Haydée

    2012-10-01

    Glyphosate-based formulations are among the most widely used herbicides in the world. The effect of the formulation Glifosato Atanor(®) on freshwater microbial communities (phytoplankton, bacterioplankton, periphyton and zooplankton) was assessed through a manipulative experiment using six small outdoor microcosms of small volume. Three of the microcosms were added with 3.5 mg l(-1) of glyphosate whereas the other three were left as controls without the herbicide. The treated microcosms showed a significant increase in total phosphorus, not fully explained by the glyphosate present in the Glifosato Atanor(®). Therefore, part of the phosphorus should have come from the surfactants of the formulation. The results showed significant direct and indirect effects of Glifosato Atanor(®) on the microbial communities. A single application of the herbicide caused a fast increase both in the abundance of bacterioplankton and planktonic picocyanobacteria and in chlorophyll a concentration in the water column. Although metabolic alterations related to oxidative stress were induced in the periphyton community, the herbicide favored its development, with a large contribution of filamentous algae typical of nutrient-rich systems, with shallow and calm waters. An indirect effect of the herbicide on the zooplankton was observed due to the increase in the abundance of the rotifer Lecane spp. as a consequence of the improved food availability given by picocyanobacteria and bacteria. The formulation affected directly a fraction of copepods as a target. It was concluded that the Glifosato Atanor(®) accelerates the deterioration of the water quality, especially when considering small-volume water systems.

  3. Toxicity of Cúspide 480SL® spray mixture formulation of glyphosate to aquatic organisms.

    Science.gov (United States)

    Currie, Zachary; Prosser, Ryan S; Rodriguez-Gil, Jose Luis; Mahon, Kim; Poirier, Dave; Solomon, Keith R

    2015-05-01

    In 2011, an alternative formulation of glyphosate (Cúspide 480SL®) was chosen to replace Roundup-SL®, Fuete-SL®, and Gly-41® for the control of Erythroxylum coca, the source of cocaine, in Colombia. Cúspide 480SL contains the active ingredient glyphosate isopropylamine (IPA) salt, which is the same active ingredient used in previous formulations. However, Cúspide 480SL contains an alkyl polyglycoside surfactant rather than the polyethoxylated tallow amine (POEA) surfactant used in other formulations and known to be more toxic to nonprimary producing aquatic organisms than glyphosate itself. An adjuvant, Cosmo-Flux F411, and water also are added to the spray mixture before application. Aquatic ecosystems adjacent to the target coca fields might be exposed to the spray mix, placing aquatic organisms at risk. Because no toxicity data were available for spray mixture on aquatic organisms, acute toxicity tests were conducted on aquatic plants, invertebrates, and fish, by using the Cúspide 480SL spray mix as described on the label. Based on the median effective concentration (EC50) values for similar organisms, the spray mixture was less toxic to aquatic organisms than formulations previously used for the control of coca (i.e., Roundup-SL, Fuete-SL, and Gly-41). A physical effect induced by Cosmo-Flux F411 was observed in Daphnia magna, Ceriodaphnia dubia, and Hyalella azteca, causing the invertebrates to be trapped in an oily film that was present at the surface of the water. However, a hazard assessment for the Cúspide 480SL spray mix, using estimated worst-case exposure scenario concentrations and EC50 values from the toxicity tests, indicated de minimis hazard for the tested aquatic animals, with hazard quotients all <1.

  4. RothC simulation of carbon accumulation in soil after repeated application of widely different organic amendments

    DEFF Research Database (Denmark)

    Peltre, Clément; Christensen, Bent Tolstrup; Dragon, Sophine

    2012-01-01

    Multi-compartment soil carbon (C) simulation models such as RothC are widely used for predicting changes in C stocks of arable soils. However, rigorous routines for establishing entry pools that account for the diversity of exogenous organic matter (EOM) applied to croplands are still lacking. We...... obtained data on changes in soil C stocks after repeated applications of EOM from four long-term experiments (LTEs): Askov K2 (Denmark, 31 yrs), Qualiagro (France, 11 yrs), SERAIL (France, 14 yrs) and Ultuna (Sweden, 52 yrs). The adjustment of the partition coefficients of total organic C in EOM (EOM......-TOC) into the labile, resistant and humified entry pools of RothC (fDPM, fRPM, fHUM, respectively) provided a successful fit to the accumulation of EOM-derived C in the LTE soils. Equations estimating the EOM partition coefficients in the RothC model were based on an indicator (IROC) of the EOM-TOC potentially...

  5. Changes in Soluble-N in Forest and Pasture Soils after Repeated Applications of Tannins and Related Phenolic Compounds

    Directory of Open Access Journals (Sweden)

    Jonathan J. Halvorson

    2012-01-01

    Full Text Available Tannins (produced by plants can reduce the solubility of soil-N. However, comparisons of tannins to related non-tannins on different land uses are limited. We extracted soluble-N from forest and pasture soils (0–5 cm with repeated applications of water (Control or solutions containing procyanidin from sorghum, catechin, tannic acid, β-1,2,3,4,6-penta-O-galloyl-D-glucose (PGG, gallic acid, or methyl gallate (10 mg g−1 soil. After eight treatments, samples were rinsed with cool water (23°C and incubated in hot water (16 hrs, 80°C. After each step, the quantity of soluble-N and extraction efficiency compared to the Control was determined. Tannins produced the greatest reductions of soluble-N with stronger effects on pasture soil. Little soluble-N was extracted with cool water but hot water released large amounts in patterns influenced by the previous treatments. The results of this study indicate hydrolyzable tannins like PGG reduce the solubility of labile soil-N more than condensed tannins like sorghum procyanidin (SOR and suggest tannin effects will vary with land management. Because they rapidly reduce solubility of soil-N and can also affect soil microorganisms, tannins may have a role in managing nitrogen availability and retention in agricultural soils.

  6. Vacuolar glyphosate-sequestration correlates with glyphosate resistance in ryegrass (Lolium spp.) from Australia, South America, and Europe: a 31P NMR investigation.

    Science.gov (United States)

    Ge, Xia; d'Avignon, D André; Ackerman, Joseph J H; Collavo, Alberto; Sattin, Maurizio; Ostrander, Elizabeth L; Hall, Erin L; Sammons, R Douglas; Preston, Christopher

    2012-02-01

    Lolium spp., ryegrass, variants from Australia, Brazil, Chile, and Italy showing differing levels of glyphosate resistance were examined by (31)P NMR. Extents of glyphosate (i) resistance (LD(50)), (ii) inhibition of 5-enopyruvyl-shikimate-3-phosphate synthase (EPSPS) activity (IC(50)), and (iii) translocation were quantified for glyphosate-resistant (GR) and glyphosate-sensitive (GS) Lolium multiflorum Lam. variants from Chile and Brazil. For comparison, LD(50) and IC(50) data for Lolium rigidum Gaudin variants from Italy were also analyzed. All variants showed similar cellular uptake of glyphosate by (31)P NMR. All GR variants showed glyphosate sequestration within the cell vacuole, whereas there was minimal or no vacuole sequestration in the GS variants. The extent of vacuole sequestration correlated qualitatively with the level of resistance. Previous (31)P NMR studies of horseweed ( Conyza canadensis (L.) Cronquist) revealed that glyphosate sequestration imparted glyphosate resistance. Data presented herein suggest that glyphosate vacuolar sequestration is strongly contributing, if not the major contributing, resistance mechanism in ryegrass as well.

  7. Genotoxic potential of glyphosate formulations: mode-of-action investigations.

    Science.gov (United States)

    Heydens, William F; Healy, Charles E; Hotz, Kathy J; Kier, Larry D; Martens, Mark A; Wilson, Alan G E; Farmer, Donna R

    2008-02-27

    A broad array of in vitro and in vivo assays has consistently demonstrated that glyphosate and glyphosate-containing herbicide formulations (GCHF) are not genotoxic. Occasionally, however, related and contradictory data are reported, including findings of mouse liver and kidney DNA adducts and damage following intraperitoneal (ip) injection. Mode-of-action investigations were therefore undertaken to determine the significance of these contradictory data while concurrently comparing results from ip and oral exposures. Exposure by ip injection indeed produced marked hepatic and renal toxicity, but oral administration did not. The results suggest that ip injection of GCHF may induce secondary effects mediated by local toxicity rather than genotoxicity. Furthermore, these results continue to support the conclusion that glyphosate and GCHF are not genotoxic under exposure conditions that are relevant to animals and humans.

  8. EMERGÊNCIA E ESTABELECIMENTO DE PLANTAS CULTIVADAS APÓS APLICAÇÃO DE GLYPHOSATE

    Directory of Open Access Journals (Sweden)

    BELUCI, Lucas Ribeiro

    2014-04-01

    Full Text Available The research aimed to study the effect glyphosate doses, used in the sugarcane chemical destruction, on the emergence and early development of soybean, corn and peanut, sown in succession. An experiment was conducted for each crop in pots using a randomized design with treatments arranged in a 2 x 6 factorial and four replications with seeding times (1 and 12 days after application and glyphosate doses (0, 1440, 2160, 2880, 3600 and 4320 g ha-1. The experimental units consisted of plastic pots (3L filled with steep bank. The herbicide was applied by spraying pressurized bar with four flat fan jet ( TT110/02 , spaced 0.50 m, constant pressure of 2.1 kgf cm- 2 and 260 L ha- 1 spray volume. After were sowed 15 seeds up to 3 inches deep with thinning at 14 days after seeding (DAS, counting the number of germinated plants. The remaining plants were evaluated (35 DAS for height, number of leaves and trifoliate leaves (soybean and total chlorophyll content. In laboratory was characterized the profile of α-esterase isozyme 14 days after herbicide application by electrophoresis on acrylamide gel. All glyphosate doses applied with 1 or 12 days before sowing harmed only the number of peanuts plants. But glyphosate to 3600 g a.e. ha-1 stimulated the height and dry matter accumulation in plants emerged from peanuts, soybeans and corn. As to metabolism, doses did not change the isoforms number of α-esterase peanut plants, however, altered in soybean (all doses and corn (dose> than 2880 g ha-1. Estudou-se o efeito das doses de glyphosate utilizadas à destruição química da cana-de-açúcar, sobre a emergência e desenvolvimento inicial de soja, milho e amendoim, semeados em sucessão. Conduziu-se um experimento para cada cultura, em vasos, utilizando-se delineamento inteiramente casualizado com tratamentos dispostos em esquema fatorial 2 x 6 em quatro repetições, sendo épocas de semeadura (1 e 12 dias após aplicação e doses de glyphosate (0; 1440

  9. Danos visuais e anatômicos causados pelo glyphosate em folhas de Eucalyptus grandis Visible and anatomic damages caused by glyphosate in Eucalyptus grandis leaves

    Directory of Open Access Journals (Sweden)

    L.D. Tuffi Santos

    2008-03-01

    effects of four commercial glyphosate formulations under simulated spray drift (Scout®, Roundup NA®, Roundup transorb® and Zapp QI® on the morphoanatomy of six Eucalyptus grandis clones (UFV01, UFV02, UFV03, UFV04, UFV05 and UFV06. Following glyphosate application (129.6 g ha-1, symptoms were monitored daily and, at 14 days, leaf samples from the regions without visible symptoms were collected for microscopic analysis. All clones presented chlorosis and necrosis at the fourth day of glyphosate exposure, regardless of the formulation used. The UFV04 clone did not show any anatomical damage. The other clones suffered plasmolysis, cellular collapse, hypertrophy and formation of cicatrisation tissue. However, changes in leaf blade thickness were not observed. Plants exposed to Roundup transorb® presented the greatest visible intoxication percentage. Anatomically, plants exposed to Roundup NA® showed a higher number of damages. Analysis considering both anatomic and visible damages showed that UFV06 clone was the most susceptible to the formulations tested. The results confirmed the diagnostic and prognostic value of visual and anatomical analysis, respectively, and showed that these parameters are essential to evaluate clone susceptibility and the the phytotoxic potential of herbicides.

  10. The possible role of quinate in the mode of action of glyphosate and acetolactate synthase inhibitors.

    Science.gov (United States)

    Orcaray, Luis; Igal, María; Marino, Daniel; Zabalza, Ana; Royuela, Mercedes

    2010-03-01

    The herbicide glyphosate inhibits the biosynthesis of aromatic amino acids by blocking the shikimate pathway. Imazethapyr and chlorsulfuron are two herbicides that act by inhibiting branched-chain amino acid biosynthesis. These herbicides stimulate secondary metabolism derived from the aromatic amino acids. The aim of this study was to test if they cause any cross-effect in the amino acid content and if they have similar effects on the shikimate pathway. The herbicides inhibiting two different amino acid biosynthesis pathways showed a common pattern in general content of free amino acids. There was a general increase in total free amino acid content, with a transient decrease in the proportion of amino acids whose pathways were specifically inhibited. Afterwards, an increase in these inhibited amino acids was detected; this was probably related to proteolysis. All herbicides caused quinate accumulation. Exogenous application of quinate arrested growth, decreased net photosynthesis and stomatal conductance and was ultimately lethal, similarly to glyphosate and imazethapyr. Quinate accumulation was a common effect of the two different classes of herbicide. Moreover, exogenous quinate application had phytotoxic effects, showing that this plant metabolite can trigger the toxic effects of the herbicides. This ability to mimic the herbicide effects suggests a possible link between the mode of action of these herbicides and the potential role of quinate as a natural herbicide.

  11. Manejo de Conyza bonariensis resistente ao herbicida glyphosate

    OpenAIRE

    Paula,J.M.; Vargas,L.; AGOSTINETTO,D.; NOHATTO, M. A.

    2011-01-01

    C. bonariensis (Conyza bonariensis) é uma planta daninha da família Asteraceae, amplamente distribuída no Brasil, com presença marcante nos Estados do Rio Grande do Sul e do Paraná. Biótipos de C. bonariensis resistentes ao glyphosate foram identificados nos Estados do Rio Grande do Sul, Paraná e São Paulo. O objetivo deste trabalho foi avaliar o efeito de diferentes manejos de inverno e na pré-semeadura da soja sobre a população de plantas de C. bonariensis resistente ao herbicida glyphosate...

  12. Atividade de glutationa S-transferase na degradação do herbicida glyphosate em plantas de milho (Zea mays Glutathione S-transferase activity on the degradation of the herbicide glyphosate in maize (Zea mays plants

    Directory of Open Access Journals (Sweden)

    A.C. Cataneo

    2003-08-01

    activity of this enzyme in glyphosate-treated maize plants. The experimental design was completely randomized, in a 4 x 4 factorial arrangement, with four treatments (glyphosate at concentrations of 1,000, 2,500 and 5,000 ppm and control plant treated with water and four developmental stages (9, 16, 23 and 30 days after emergence, with five replicates. The herbicide was applied on the maize plant shoots, which were collected at 24, 48 and 72 hours after herbicide application and utilized for determining the GST activity and lipoperoxide content. It was verified that glyphosate does not change the lipoperoxide content, but increases GST activity for most treatments utilized, indicating its action in the degradation of glyphosate in maize plants.

  13. Modelling fate and transport of glyphosate and AMPA in the Meuse catchment to assess the contribution of different pollution sources

    Science.gov (United States)

    Desmet, Nele; Seuntjens, Piet

    2013-04-01

    Large river basins have multiple sources of pesticides and usually the pollution sources are spread over the entire catchment. The cumulative effect of pesticides entering the river system in upstream areas and the formation of persistent degradation products can compromise downstream water use e.g. raw water quality for drinking water abstractions. For assessments at catchment scale pesticide fluxes coming from different sources and sub basins need to be taken into account. To improve management strategies, a sound understanding of the sources, emission routes, transport, environmental fate and conversion of pesticides is needed. In the Netherlands, the Meuse river basin is an important source for drinking water production. The river suffers from elevated concentrations of glyphosate and aminomethylphosphonic acid (AMPA). For AMPA it is rather unclear to what extent the pollution is related to glyphosate degradation and what is the contribution of other sources, especial phosphonates in domestic and industrial waste water. Based on the available monitoring data only it is difficult to distinguish between AMPA sources in such a large river basin. This hampers interpretation and decision making for water quality management in the Meuse catchment. Here, application of water quality models is very useful to obtain complementary information and insights. Modelling allows accounting for temporal and spatial variability in discharge and concentrations as well as distinguishing the contribution from conversion processes. In this study, a model for the river Meuse was developed and applied to assess the contribution of tributary and transnational influxes, glyphosate degradation and other sources to the AMPA pollution.

  14. Effects of a wood-based biochar on the leaching of pesticides chlorpyrifos, diuron, glyphosate and MCPA.

    Science.gov (United States)

    Cederlund, Harald; Börjesson, Elisabet; Stenström, John

    2017-04-15

    We studied the ability of a wood-based biochar to reduce the leaching of the pesticides chlorpyrifos, diuron, glyphosate and MCPA in a sand column test system. In addition, time-dependent adsorption of the pesticides to the biochar and to the sand used in the columns was determined. The sorption kinetics was shown to be controlled by the log Kow-values of the pesticides and sorption rates varied in the order: chlorpyrifos (log Kow = 4.7) > diuron (log Kow = 2.87) > MCPA (log Kow = -0.8) > glyphosate (log Kow = -3.2). Glyphosate sorbed very weakly to the biochar but strongly to the sand. Biochar was most effective at retaining the pesticides if applied as a distinct layer rather than mixed with the sand. Leaching of diuron and MCPA was reduced by biochar application, and the retention was linearly related to the thickness of the biochar layers. However, leaching of chlorpyrifos and glyphosate was not affected by biochar addition. Leaching was low for all pesticides when the pesticides were added directly to biochar that was then added to the column. Together, our results suggest that a viable strategy for using biochar as a means to mitigate leaching of pesticides may be to use it as an adsorptive layer directly on or close to the soil surface. This would be especially useful in areas where pesticides are routinely handled and potentially spilled. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Effects of a glyphosate-based herbicide on the development of Common toads (Bufo bufo L.; Amphibia) at different temperatures

    Science.gov (United States)

    Baier, Fabian; Gruber, Edith; Spangl, Bernhard; Zaller, Johann G.

    2016-04-01

    Herbicides based on the active ingredient glyphosate are frequently applied in agriculture, horticulture and private gardens all over the world. Recently, leaching of glyphosate or its metabolite (AMPA) into water bodies inhabited by amphibians has been reported. However, very little is known about non-target effects of these herbicides on amphibians and even less is known to what extent different temperatures might alter these effects. Using climate chambers, we investigated the effects of the glyphosate-based herbicide Roundup PowerFlex® (480 g L-1 glyphosate, formulated as 588 g L-1 potassium salt) on the larval development of Common toads (Bufo bufo L.; Amphibia: Anura) under different temperature regimes (15°C vs. 20°C). We established five herbicide concentrations: 0, 1.5, 3, 4 mg acid equivalent L-1 and a 4 mg a.e. L-1 pulse treatment (totally three applications of 1.5, 1.5 and another 1 mg a.e. L-1) at each temperature in a full-factorial design. Each treatment combination was replicated five times, the experiment ran for 24 days. Results showed a highly significant effect of temperature on body length and body width but no effect of herbicide concentration on these growth parameters. Moreover, highly significant interactions between herbicide and temperature on body length and body width were observed suggesting that herbicides had different effects on different temperatures. In conclusion, although Roundup PowerFlex® at the tested concentrations appeared to have no acute toxicity to larvae of Common toads, the observed effects on tadpole morphology will potentially affect competitive interactions in spawning ponds of amphibia. Our findings of herbicide x temperature interactions might become more prevalent when human-induced climate change will lead to more extreme temperatures.

  16. Residue determination and levels of glyphosate in surface waters, sediments and soils associated with oil palm plantation in Tasik Chini, Pahang, Malaysia

    Science.gov (United States)

    Mardiana-Jansar, K.; Ismail, B. S.

    2014-09-01

    Levels of glyphosate and its main metabolite were determined in surface water, soil and sediment samples from an oil palm plantation area located at Tasik Chini, Pahang, Malaysia. The optimization analytical method has been developed for the determination of glyphosate herbicide and its metabolite amino-methyl-phosphonic acid (AMPA) in surface waters to a level of 0.1μg/L, while in sediments and soils to a level of 0.5μg/g with a good linearity in the calibration range of 1-100μg/L. The procedure involves a pre-columnderivatization step with 9-fluorenyl-methyl-chloroformate (FMOC-Cl) yielding highly fluorescent derivatives of the analytes which can be determined by HPLC with fluorescence detection. In the field, levels of glyphosate in surface waters ranges from not detected to 1.0mg/L, while in soils and sediments were from not detected to 6.0mg/kg. For AMPA, the residues in surface waters were between not detected to 2.0mg/L, while in soil and sediment samples were from not detected to 5mg/kg. This variation of glyphosate and AMPA levels depended directly on time of pesticide application and the season.

  17. Intermolecular interaction studies of glyphosate with water

    Science.gov (United States)

    Manon, Priti; Juglan, K. C.; Kaur, Kirandeep; Sethi, Nidhi; Kaur, J. P.

    2017-07-01

    The density (ρ), viscosity (η) and ultrasonic velocity (U) of glyphosate with water have been measured on different ultrasonic frequency ranges from 1MHz, 2MHz, 3MHz & 5MHz by varying concentrations (0.05%, 0.10%, 0.15%, 0.20%, 0.25%, 0.30%, 0.35%, & 0.40%) at 30°C. The specific gravity bottle, Ostwald's viscometer and quartz crystal interferometer were used to determine density (ρ), viscosity (η) and ultrasonic velocity (U). These three factors contribute in evaluating the other parameters as acoustic impedance (Z), adiabatic compressibility (β), relaxation time (τ), intermolecular free length (Lf), free volume (Vf), ultrasonic attenuation (α/f2), Rao's constant (R), Wada's constant (W) and relative strength (R). Solute-solvent interaction is confirmed by ultrasonic velocity and viscosity values, which increases with increase in concentration indicates stronger association between solute and solvent molecules. With rise in ultrasonic frequency the interaction between the solute and solvent particles decreases. The linear variations in Rao's constant and Wada's constant suggest the absence of complex formation.

  18. Photodegradation of glyphosate in the ferrioxalate system

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yong [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China); Wu Feng [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)], E-mail: fengwu@whu.edu.cn; Lin Yixin; Deng Nansheng [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China); Bazhin, Nikolai; Glebov, Evgeni [Institute of Chemical Kinetics and Combustion, 3 Institutskaya St., Novosibirsk 630090 (Russian Federation)

    2007-09-05

    The photoinduced degradation of glyphosate (GLP) in the ferrioxalate system was investigated under irradiation with a 250 W metal halide lamp ({lambda} {>=} 365 nm). The efficiency of orthophosphates release, representing the photodegradation efficiency of GLP, increased with decreasing the initial concentrations of GLP and Fe(III)/oxalate ratios. At acidic pH value in the range of 3.5-5.0, higher efficiency of orthophosphates release up to 60.6% was achieved, while the efficiency dropped to 42.1% at pH 6.0. The photochemical process mainly involved the predominant species of iron(III), namely Fe(C{sub 2}O{sub 4}){sub 2}{sup -} and Fe(C{sub 2}O{sub 4}){sub 3}{sup 3-}, which lead to the formation of hydroxyl radicals in the presence of dissolved oxygen under UV-vis irradiation. Also, the complexation of GLP with Fe(III) obviously increased the light absorption of GLP and facilitated its degradation by direct photolysis. The ninhydrin test for primary amines showed that the GLP was attacked by hydroxyl radicals with C-N cleavage to yield aminomethylphosphonic acid (AMPA) and C-P cleavage to yield sarcosine. The photodegradation may be enhanced by the decomposition of reactive radicals produced through ligand-to-metal charge transfer (LMCT) of ferric-GLP complexes.

  19. SORPTION AND DESORPTION OF GLYPHOSATE IN MOLLISOLS AND ULTISOLS SOILS OF ARGENTINA.

    Science.gov (United States)

    Gómez Ortiz, Ana Maria; Okada, Elena; Bedmar, Francisco; Costa, José Luis

    2017-05-08

    In Argentina, glyphosate use has increased exponentially in the past years due to the widespread adoption of no-till management combined with genetically modified glyphosate-resistant crops. This massive use of glyphosate has created concern about its potential environmental impact. Sorption-desorption of glyphosate was studied in three Argentinean soils with contrasting characteristics. Glyphosate sorption isotherms were modeled using the Freundlich equation to estimate the sorption coefficient (Kf ). Glyphosate sorption was high and the Kf varied from 115.6 to 1612 mg (1-1/n) L(1/n) /Kg. Cerro Azul soil had the highest glyphosate sorption capacity due to a combination of factors such as higher clay content, CEC, total Fe, Al oxides and lower available phosphorous and pH. Desorption isotherms were also modeled using the Freundlich equation. In general, desorption was very low (glyphosate strongly sorbs to the soils and that it is almost an irreversible process. Anguil soil had a significant higher desorption coefficient (Kfd ) than the other soils, associated with its lower clay content and higher pH and phosphorous. Glyphosate high sorption and low desorption to the studied soils may prevent groundwater contamination. However, it may also affect its bioavailability increasing its persistence and favoring its accumulation in environment. Results of this study contribute to the knowledge and characterization of glyphosate retention in different soils. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. PVP capped silver nanocubes assisted removal of glyphosate from water-A photoluminescence study.

    Science.gov (United States)

    Sarkar, Sumit; Das, Ratan

    2017-10-05

    Glyphosate [N-phosphono-methylglycine (PMG)] is the most used herbicide worldwide and it has been reported very recently that Glyphosate is very harmful and can produce lots of diseases such as alzheimer and parkinson's disease, depression, cancer, infertility including genotoxic effects. As it is mostly present in stable water body and ground water system, its detection and removal is very important. Here, we have shown a fluorescence technique for the removal of glyphosate from water using chemically synthesized polyvinylpyrrolidone (PVP) silver nanocrystals. Transmission Electron Microscopy (TEM) study shows the average size of silver nanocrystals of 100nm approximately with a morphology of cubic shape. Glyphosate does not show absorption in the visible region. But both glyphosate and silver nanocrystals show strong fluorescence in the visible region. So, photoluminescence study has been successfully utilized to detect the glyphosate in water samples and on treating the glyphosate contaminated water sample with silver nanocrystals, the sample shows no emission peak of glyphosate at 458nm. Thus, this approach is a promising and very rapid method for the detection and removal of glyphosate from water samples on treatment with silver nanocubes. NMR spectra further confirms that the silver nanocrystals treated contaminated water samples are glyphosate free. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Dissipation of glyphosate and aminomethylphosphonic acid in water and sediment of two Canadian prairie wetlands.

    Science.gov (United States)

    Degenhardt, Dani; Humphries, David; Cessna, Allan J; Messing, Paul; Badiou, Pascal H; Raina, Renata; Farenhorst, Annemieke; Pennock, Dan J

    2012-01-01

    Glyphosate [N-(phosphonomethyl)glycine] is the active ingredient of several herbicide products first registered for use in 1974 under the tradename Roundup. The use of glyphosate-based herbicides has increased dramatically over the last two decades particularly in association with the adoption of glyphosate-tolerant crops. Glyphosate has been detected in a range of surface waters but this is the first study to monitor its fate in prairie wetlands situated in agricultural fields. An ephemeral wetland (E) and a semi-permanent wetland (SP) were each divided into halves using a polyvinyl curtain. One half of each wetland was fortified with glyphosate with the added mass simulating an accidental direct overspray. Glyphosate dissipated rapidly in the water column of the two prairie wetlands studied (DT(50) values of 1.3 and 4.8 d) which may effectively reduce the impact of exposure of aquatic biota to the herbicide. Degradation of glyphosate to its major metabolite aminomethylphosphonic acid (AMPA) and sorption of the herbicide to bottom sediment were more important pathways for the dissipation of glyphosate from the water column than movement of the herbicide with infiltrating water. Presently, we are not aware of any Canadian guidelines for glyphosate residues in sediment of aquatic ecosystems. Since a substantial portion of glyphosate entering prairie wetlands will become associated with bottom sediments, particularly in ephemeral wetlands, guidelines would need to be developed to assess the protection of organisms that spend all or part of their lifecycle in sediment.

  2. The effect of two glyphosate formulations on a small, diurnal lizard (Oligosoma polychroma).

    Science.gov (United States)

    Carpenter, Joanna K; Monks, Joanne M; Nelson, Nicola

    2016-04-01

    Formulations of glyphosate-based herbicides continue to dominate the global herbicide market, while there continue to be concerns regarding the impact of this herbicide on non-target organisms. Research also indicates that the additives within certain glyphosate formulations, such as surfactants, are actually more toxic than the glyphosate active ingredient alone. Concerns arise in particular when glyphosate formulations are proposed for vegetation control in areas inhabited by rare or threatened species. Although the effect of glyphosate on birds and mammals is well studied, reptiles remain neglected in ecotoxicological studies. We investigated whether dermal exposure to two different commercial glyphosate formulations affected performance measures in the New Zealand common skink (Oligosoma polychroma). Fifty-eight skinks were each placed in a box of straw to simulate field conditions and sprayed once with Agpro Glyphosate 360, Yates Roundup Weedkiller (both at the label-specified concentrations of 144 mg glyphosate per 1 L water), or water (control). Agpro Glyphosate 360 contained ethoxylated tallow amine at a concentration of glyphosate formulation had a significant impact on mass. However, skinks treated with Yates Roundup Weedkiller selected significantly higher temperatures across 3 weeks following exposure. This heat-seeking behaviour could be a fever response to increase metabolism and thereby counteract physiological stress.

  3. Influencing factors on regional differences in glyphosate use in North German arable farming

    Directory of Open Access Journals (Sweden)

    Andert, Sabine

    2016-02-01

    Full Text Available Glyphosate is the worldwide mostly used herbicide substance. Glyphosate use in arable cropping is under strong discussion in scientific and public communities. In the present study, we investigated the use of glyphosate from 15 farms in four districts in North German arable farming from 2005 until 2014. Objective of our research is to reveal influencing factors on glyphosate use intensity. The farm structures differ between two West districts (Diepholz, Uelzen and two East districts (Fläming, Oder-Spree. We used the Standardised Treatment Index (STI to quantify pesticide use intensity. We used multiple regressions to estimate the relationship between farm characteristics and glyphosate use. Glyphosate use intensity differs substantially between the study districts and crops. Farmers in the Eastern districts (Fläming and Oder-Spree used significantly larger amounts of glyphosate. We further proved that the variability of glyphosate use was mainly influenced by the factor “Farm”. Moreover, we could show that glyphosate use is significantly influenced by the factors tillage, farm type, farm size and on-farm labour. Non-inversion tillage and glyphosate use co-incidences mainly on large farms in the East German districts. Hence, we conclude that these farms either regionally adapt their cropping systems due to climatic reasons or for economic profit.

  4. Glyphosate-rich air samples induce IL-33, TSLP and generate IL-13 dependent airway inflammation.

    Science.gov (United States)

    Kumar, Sudhir; Khodoun, Marat; Kettleson, Eric M; McKnight, Christopher; Reponen, Tiina; Grinshpun, Sergey A; Adhikari, Atin

    2014-11-01

    Several low weight molecules have often been implicated in the induction of occupational asthma. Glyphosate, a small molecule herbicide, is widely used in the world. There is a controversy regarding a role of glyphosate in developing asthma and rhinitis among farmers, the mechanism of which is unexplored. The aim of this study was to explore the mechanisms of glyphosate induced pulmonary pathology by utilizing murine models and real environmental samples. C57BL/6, TLR4-/-, and IL-13-/- mice inhaled extracts of glyphosate-rich air samples collected on farms during spraying of herbicides or inhaled different doses of glyphosate and ovalbumin. The cellular response, humoral response, and lung function of exposed mice were evaluated. Exposure to glyphosate-rich air samples as well as glyphosate alone to the lungs increased: eosinophil and neutrophil counts, mast cell degranulation, and production of IL-33, TSLP, IL-13, and IL-5. In contrast, in vivo systemic IL-4 production was not increased. Co-administration of ovalbumin with glyphosate did not substantially change the inflammatory immune response. However, IL-13-deficiency resulted in diminished inflammatory response but did not have a significant effect on airway resistance upon methacholine challenge after 7 or 21 days of glyphosate exposure. Glyphosate-rich farm air samples as well as glyphosate alone were found to induce pulmonary IL-13-dependent inflammation and promote Th2 type cytokines, but not IL-4 for glyphosate alone. This study, for the first time, provides evidence for the mechanism of glyphosate-induced occupational lung disease.

  5. Repeated applications of CPPU on highbush blueberry cv. Duke increase yield and enhance fruit quality at harvest and during postharvest

    Directory of Open Access Journals (Sweden)

    Jorge B Retamales

    2014-04-01

    Full Text Available Applications of N-(2-chloro-4-pyridyl-N'-phenylurea (CPPU can increase blueberry (Vaccinium corymbosum L. yield and fruit size, but their impact on postharvest is unknown. We studied repeated CPPU applications effects on yield and quality (harvest, postharvest, over 2 yr on mature 'Duke' plants in South-Central Chile. The first year, 5 or 10 mL L-1 CPPU was applied at 3, 10, and/or 17 d after full bloom (DAFB plus a non-sprayed control. The second year, 5 or 10 mL L-1 CPPU were sprayed 10 and 17 DAFB plus a control. The first year, only 10 mL L-1 CPPU sprayed 3+17 DAFB increased yield (32.5% > control; 10 mL L-1 CPPU applied 10 or 3+17 DAFB had highest fruit diameter; and 10 mL L-1 CPPU at 17 DAFB or at 3+10+17 DAFB had highest soluble solids. Overall, 10 mL L-1 CPPU applied 3+17 DAFB, was the best treatment for year one, since it increased fruit yield and diameter, while soluble solids and postharvest weight loss were similar to control. The second year, 10 mL L-1 CPPU reduced fruit coloration (blue color coverage index: BCCI and soluble solids, but not firmness at harvest. This rate increased berry weight (24.2% and fruit wax (59% > wax coverage index: WCI at harvest. Harvest and postharvest WCI increased consistently as CPPU rate increased. CPPU reduced fruit rotting (15% at 45+5 evaluation. During storage, CPPU-treated-fruit had a slower decrease in firmness (30.5% < control at 30+1, but no difference at 30+5. CPPU-treated-fruit usually had higher post harvest soluble solids. Ten mL L-1 CPPU retarded color evolution at harvest and at 30+1, but not at 30+5, 40+1 or 40+5.

  6. Foliar Potassium Fertilizer Additives Affect Soybean Response and Weed Control with Glyphosate

    Directory of Open Access Journals (Sweden)

    Kelly A. Nelson

    2012-01-01

    Full Text Available Research in 2004 and 2005 determined the effects of foliar-applied K-fertilizer sources (0-0-62-0 (%N-%P2O5-%K2O-%S, 0-0-25-17, 3-18-18-0, and 5-0-20-13 and additive rates (2.2, 8.8, and 17.6 kg K ha−1 on glyphosate-resistant soybean response and weed control. Field experiments were conducted at Novelty and Portageville with high soil test K and weed populations and at Malden with low soil test K and weed populations. At Novelty, grain yield increased with fertilizer additives at 8.8 kg K ha−1 in a high-yield, weed-free environment in 2004, but fertilizer additives reduced yield up to 470 kg ha−1 in a low-yield year (2005 depending on the K source and rate. At Portageville, K-fertilizer additives increased grain yield from 700 to 1160 kg ha−1 compared to diammonium sulfate, depending on the K source and rate. At Malden, there was no yield response to K sources. Differences in leaf tissue K (P=0.03, S (P=0.03, B (P=0.0001, and Cu (P=0.008 concentrations among treatments were detected 14 d after treatment at Novelty and Malden. Tank mixtures of K-fertilizer additives with glyphosate may provide an option for foliar K applications.

  7. Glyphosate e adubação foliar com manganês na cultura da soja transgênica Glyphosate and foliar fertilization using manganese in transgenic soybean crop

    Directory of Open Access Journals (Sweden)

    N.M. Correia

    2009-01-01

    evaluate the interaction of transgenic soybean sprayed with glyphosate and manganese foliar fertilization. The experiment was carried out under field conditions in the agricultural year 2007/2008 on the UNESP Campus Teaching, Research and Production Farm in Jaboticabal, São Paulo, Brazil. An experiment was arranged in a randomized block design, in a factorial scheme (4 x 4, with four replications. Four weed controls [glyphosate (c.p. Roundup Ready at 0.72 and 1.20 kg ha-1 of equivalent acid; fluazifop-p-butyl plus fomesafen (c.p. Fusiflex at 0.25 plus 0.25 kg ha-1 and under mechanical control, without herbicide] and four manganese rates (0, 42, 84 and 126 g ha-1 were applied on the soybean leaf. The treatments did not significantly affect grain yield, manganese concentration in the soil, height and dry matter of the soybean plants. Only the mixture fluazifop-p-butyl plus fomesafen caused visible injuries in the plants. However, the symptoms were restricted to the leaves that intercepted spraying. The herbicide treatments did not differ from the control for 100 grain mass, although the plants treated with glyphosate 0.72 kg ha-1 presented less grain mass. Manganese application did not influence element concentration in the plant treated with glyphosate and under mechanical control. Therefore, glyphosate did not impair manganese absorption or metabolism by the plant. Growth and development of the herbicide-treated plants were statistically similar to those of the plants not treated with herbicides.

  8. Efficacy of electrostatically-charged Glyphosate on ryegrass

    Science.gov (United States)

    Glyphosate, (N-(phosphonomethyl)glycine, a broad spectrum, systemic, post-emergence herbicide, is used extensively for weed control in production agriculture throughout the world. The objective of this research was to determine whether or not it is beneficial to electrostatically charge herbicidal s...

  9. Weed species shifts in glyphosate-resistant crops.

    Science.gov (United States)

    Owen, Micheal D K

    2008-04-01

    The adoption of glyphosate-based crop production systems has been one of the most important revolutions in the history of agriculture. Changes in weed communities owing to species that do not respond to current glyphosate-based management tactics are rapidly increasing. Clearly, glyphosate-resistant crops (GRCs) do not influence weeds any more than non-transgenic crops. For most crops, the trait itself is essentially benign in the environment. Rather, the weed control tactics imposed by growers create the ecological selection pressure that ultimately changes the weed communities. This is seen in the adoption of conservation tillage and weed management programs that focus on one herbicide mode of action and have hastened several important weed population shifts. Tillage (disturbance) is one of the primary factors that affect changes in weed communities. The intense selection pressure from herbicide use will result in the evolution of herbicide-resistant weed biotypes or shifts in the relative prominence of one weed species in the weed community. Changes in weed communities are inevitable and an intrinsic consequence of growing crops over time. The glyphosate-based weed management tactics used in GRCs impose the selection pressure that supports weed population shifts. Examples of weed population shifts in GRCs include common waterhemp [Amaranthus tuberculatus (Moq ex DC) JD Sauer], horseweed (Conyza canadensis L), giant ragweed (Ambrosia trifida L) and other relatively new weed problems. Growers have handled these weed population shifts with varying success depending on the crop. Copyright (c) 2008 Society of Chemical Industry.

  10. Glyphosate resistant weeds - a threat to conservation agriculture

    Science.gov (United States)

    Glyphosate-resistant weeds are now present throughout the Southeast. Hundreds of thousands of conservation tillage cotton acres, some currently under USDA Natural Resources Conservation Service (NRCS) conservation program contracts, are at risk of being converted to higher-intensity tillage systems....

  11. Effects of glyphosate acid and the glyphosate-commercial formulation (Roundup) on Dimorphandra wilsonii seed germination: Interference of seed respiratory metabolism.

    Science.gov (United States)

    Gomes, Marcelo Pedrosa; da Silva Cruz, Fernanda Vieira; Bicalho, Elisa Monteze; Borges, Felipe Viègas; Fonseca, Marcia Bacelar; Juneau, Philippe; Garcia, Queila Souza

    2017-01-01

    Glyphosate-formulations are widely used in the Brazilian Cerrado (neotropical savanna) with little or no control, threatening population of the endangered species Dimorphandra wilsonii. We investigated the toxicity of different concentrations (0, 5, 25 and 50 mg l(-1)) of glyphosate acid and one of its formulations (Roundup(®)) on seed germination in D. wilsonii. Glyphosate acid and Roundup drastically decreased seed germination by decreasing seed respiration rates. The activation of antioxidant enzymes, ascorbate peroxidase and catalase assure no hydrogen peroxide accumulation in exposed seeds. Glyphosate acid and the Roundup-formulation negatively affected the activities of enzymes associated with the mitochondrial electron transport chain (ETC), with Complex III as its precise target. The toxicity of Roundup-formulation was greater than that of glyphosate acid due to its greater effects on respiration. The herbicide glyphosate must impair D. wilsonii seed germination by disrupting the mitochondrial ETC, resulting in decreased energy (ATP) production. Our results therefore indicate the importance of avoiding (or closely regulating) the use of glyphosate-based herbicides in natural Cerrado habitats of D. wilsonni as they are toxic to seed germination and therefore threaten conservation efforts. It will likewise be important to investigate the effects of glyphosate on the seeds of other species and to investigate the impacts of these pesticides elsewhere in the world. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. In Vivo 31P-Nuclear Magnetic Resonance Studies of Glyphosate Uptake, Vacuolar Sequestration, and Tonoplast Pump Activity in Glyphosate-Resistant Horseweed1[W

    Science.gov (United States)

    Ge, Xia; d’Avignon, D. André; Ackerman, Joseph J.H.; Sammons, R. Douglas

    2014-01-01

    Horseweed (Conyza canadensis) is considered a significant glyphosate-resistant (GR) weed in agriculture, spreading to 21 states in the United States and now found globally on five continents. This laboratory previously reported rapid vacuolar sequestration of glyphosate as the mechanism of resistance in GR horseweed. The observation of vacuole sequestration is consistent with the existence of a tonoplast-bound transporter. 31P-Nuclear magnetic resonance experiments performed in vivo with GR horseweed leaf tissue show that glyphosate entry into the plant cell (cytosolic compartment) is (1) first order in extracellular glyphosate concentration, independent of pH and dependent upon ATP; (2) competitively inhibited by alternative substrates (aminomethyl phosphonate [AMPA] and N-methyl glyphosate [NMG]), which themselves enter the plant cell; and (3) blocked by vanadate, a known inhibitor/blocker of ATP-dependent transporters. Vacuole sequestration of glyphosate is (1) first order in cytosolic glyphosate concentration and dependent upon ATP; (2) competitively inhibited by alternative substrates (AMPA and NMG), which themselves enter the plant vacuole; and (3) saturable. 31P-Nuclear magnetic resonance findings with GR horseweed are consistent with the active transport of glyphosate and alternative substrates (AMPA and NMG) across the plasma membrane and tonoplast in a manner characteristic of ATP-binding cassette transporters, similar to those that have been identified in mammalian cells. PMID:25185124

  13. Potential Accumulative Effect of the Herbicide Glyphosate on Glyphosate-Tolerant Maize Rhizobacterial Communities over a Three-Year Cultivation Period

    Science.gov (United States)

    Barriuso, Jorge; Marín, Silvia; Mellado, Rafael P.

    2011-01-01

    Background Glyphosate is a herbicide that is liable to be used in the extensive cultivation of glyphosate-tolerant cultivars. The potential accumulation of the relative effect of glyphosate on the rhizobacterial communities of glyphosate-tolerant maize has been monitored over a period of three years. Methodology/Principal Findings The composition of rhizobacterial communities is known to vary with soil texture, hence, the analyses have been performed in two agricultural fields with a different soil texture. The accumulative effects of glyphosate have been monitored by means of high throughput DNA pyrosequencing of the bacterial DNA coding for the 16S rRNA hypervariable V6 region from rhizobacterial communities. The relative composition of the rhizobacterial communities does vary in each field over the three-year period. The overall distribution of the bacterial phyla seems to change from one year to the next similarly in the untreated and glyphosate-treated soils in both fields. The two methods used to estimate bacterial diversity offered consistent results and are equally suitable for diversity assessment. Conclusions/Significance The glyphosate treatment during the three-year period of seasonal cultivation in two different fields did not seem to significantly change the maize rhizobacterial communities when compared to those of the untreated soil. This may be particularly relevant with respect to a potential authorisation to cultivate glyphosate-tolerant maize in the European Union. PMID:22096595

  14. In vivo ³¹P-nuclear magnetic resonance studies of glyphosate uptake, vacuolar sequestration, and tonoplast pump activity in glyphosate-resistant horseweed.

    Science.gov (United States)

    Ge, Xia; d'Avignon, D André; Ackerman, Joseph J H; Sammons, R Douglas

    2014-11-01

    Horseweed (Conyza canadensis) is considered a significant glyphosate-resistant (GR) weed in agriculture, spreading to 21 states in the United States and now found globally on five continents. This laboratory previously reported rapid vacuolar sequestration of glyphosate as the mechanism of resistance in GR horseweed. The observation of vacuole sequestration is consistent with the existence of a tonoplast-bound transporter. (31)P-Nuclear magnetic resonance experiments performed in vivo with GR horseweed leaf tissue show that glyphosate entry into the plant cell (cytosolic compartment) is (1) first order in extracellular glyphosate concentration, independent of pH and dependent upon ATP; (2) competitively inhibited by alternative substrates (aminomethyl phosphonate [AMPA] and N-methyl glyphosate [NMG]), which themselves enter the plant cell; and (3) blocked by vanadate, a known inhibitor/blocker of ATP-dependent transporters. Vacuole sequestration of glyphosate is (1) first order in cytosolic glyphosate concentration and dependent upon ATP; (2) competitively inhibited by alternative substrates (AMPA and NMG), which themselves enter the plant vacuole; and (3) saturable. (31)P-Nuclear magnetic resonance findings with GR horseweed are consistent with the active transport of glyphosate and alternative substrates (AMPA and NMG) across the plasma membrane and tonoplast in a manner characteristic of ATP-binding cassette transporters, similar to those that have been identified in mammalian cells.

  15. Development of highly glyphosate-tolerant tobacco by coexpression of glyphosate acetyltransferase gat and EPSPS G2-aroA genes

    Institute of Scientific and Technical Information of China (English)

    Baoqing; Dun; Xujing; Wang; Wei; Lu; Ming; Chen; Wei; Zhang; Shuzhen; Ping; Zhixing; Wang; Baoming; Zhang; Min; Lin

    2014-01-01

    The widely used herbicide glyphosate targets 5-enolpyruvylshikimate-3-phosphate synthase(EPSPS).Glyphosate acetyltransferase(GAT)effectively detoxifies glyphosate by N-acetylation.With the aim of identifying a new strategy for development of glyphosate-tolerant crops,the plant expression vector pG2-GAT harboring gat and G2-aroA(encoding EPSPS)has been transformed into tobacco(Nicotiana tabacum)to develop novel plants with higher tolerance to glyphosate.Results from Southern and Western blotting analyses indicated that the target genes were integrated into tobacco chromosomes and expressed effectively at the protein level.Glyphosate tolerance was compared among transgenic tobacco plants containing gat,G2-aroA,or both genes.Plants containing both gat and G2-aroA genes were the most glyphosate-tolerant.This study has shown that a combination of different strategies may result in higher tolerance in transgenic crops,providing a new approach for development of glyphosate-tolerant crops.

  16. Process on Glyphosate-resistant Transgenic Maize%抗草甘膦转基因玉米研究进展

    Institute of Scientific and Technical Information of China (English)

    谢树章; 杨小艳; 林清; 翁建峰; 蒋晓英; 李新海; 雷开荣

    2013-01-01

      Glyphosate is a broad-spectrum, inner-absorption conducting herbicide that has been widely used in maize production. With development of plant genetic engineering technology and continuously expansion of genetically modified crops planting area, the research and development of glyphosate-resistant transgenic maize have become an important part of maize breeding. In this paper, we introduced the function mechanism of glyphosate, analyzed in detail the strategy of glyphosate-resistant plant genetic engineering. The paper also systematically reviewed the internal and external progress made in research and development of glyphosate-resistant transgenic maize, and its commercial application. It put forward strategy for studying and developing glyphosate-resistant transgenic maize in China, so as to provide relevant references for enhancing glyphosate-resistant transgenic maize research in China.%  草甘膦是广谱灭生性、内吸传导型除草剂,广泛应用于玉米生产,随着植物基因工程技术的发展以及全球转基因作物种植面积的不断增加,抗草甘膦转基因玉米研发已成为玉米育种的重要内容。介绍了草甘膦的作用机理,详细分析了抗草甘膦转基因植物基因工程策略。较为系统地分析了当前国内外抗草甘膦转基因玉米研发及商品化应用进展,进而提出了针对我国抗草甘膦转基因玉米研发的策略。以期为我国抗草甘膦转基因玉米研究提供参考。

  17. Deployment Repeatability

    Science.gov (United States)

    2016-04-01

    controlled to great precision, but in a Cubesat , there may be no attitude determination at all. Such a Cubesat might treat sun angle and tumbling rates as...could be sensitive to small differences in motor controller timing. In these cases, the analyst might choose to model the entire deployment path, with...knowledge of the material damage model or motor controller timing precision. On the other hand, if many repeated and environmentally representative

  18. A Modified phosphate-carrier protein theory is proposed as a non-target site mechanism For glyphosate resistance in weeds Teoria das proteínas carregadoras fosfato modificadas proposta como mecanismo de resistência ao herbicida glyphosate em plantas daninhas

    Directory of Open Access Journals (Sweden)

    A.C. Roso

    2010-01-01

    Full Text Available Glyphosate is an herbicide that inhibits the enzyme 5-enolpyruvyl-shikimate-3-phosphate synthase (EPSPs (EC 2.5.1.19. EPSPs is the sixth enzyme of the shikimate pathway, by which plants synthesize the aromatic amino acids phenylalanine, tyrosine, and tryptophan and many compounds used in secondary metabolism pathways. About fifteen years ago it was hypothesized that it was unlikely weeds would evolve resistance to this herbicide because of the limited degree of glyphosate metabolism observed in plants, the low resistance level attained to EPSPs gene overexpression, and because of the lower fitness in plants with an altered EPSPs enzyme. However, today 20 weed species have been described with glyphosate resistant biotypes that are found in all five continents of the world and exploit several different resistant mechanisms. The survival and adaptation of these glyphosate resistant weeds are related toresistance mechanisms that occur in plants selected through the intense selection pressure from repeated and exclusive use of glyphosate as the only control measure. In this paper the physiological, biochemical, and genetic basis of glyphosate resistance mechanisms in weed species are reviewed and a novel and innovative theory that integrates all the mechanisms of non-target site glyphosate resistance in plants is presented.Glyphosate é uma glicina fosfonada e inibe a enzima 5-enolpiruvil-shikimato-3-fosfato sintase (EPSPS (EC 2.5.1.19. EPSPS é a sexta enzima da rota do shikimato, na qual são sintetizados os compostos do metabolismo secundário e os aminoácidos aromáticos fenilalanina, tirosina e triptofano. Alguns autores hipotetizaram que seria improvável a evolução de plantas daninhas resistentes a este herbicida. As justificativas estariam relacionadas à limitada metabolização de glyphosate nas plantas, ao baixo nível de resistência obtido com a superexpressão do gene EPSPS e à alta penalidade de adaptação oriunda de mutações no

  19. Release of heavy metals during long-term land application of sewage sludge compost: Percolation leaching tests with repeated additions of compost.

    Science.gov (United States)

    Fang, Wen; Delapp, Rossane C; Kosson, David S; van der Sloot, Hans A; Liu, Jianguo

    2017-02-01

    Leaching assessment procedures have been used to determine the leachability of heavy metals as input for evaluating the risk from sewage sludge compost land application. However, relatively little attention has been paid to understanding leaching from soils with repeated application of sewage sludge compost with elevated levels of heavy metals. In this paper, leaching assessment is extended to evaluate the potential leaching of heavy metals during repetitive application of composted sewage sludge to soils. Four cycling of compost additions and percolation leaching were conducted to investigate how leaching behavior of heavy metals changed with repeated additions of compost. Results showed that repetitive additions of compost to soil significantly increased the content of organic matter, which favored the formation of reducing condition due to improved microbial activities and oxygen consumption. Establishment of reducing conditions can enhance the leaching concentrations of As by approximately 1 order of magnitude, especially for the soil rich in organic matter. For Cd, Cr, Cu, and Pb, repeated additions of compost will cause accumulation in total contents but not enhancement in leaching concentrations. The infiltration following compost additions will leach out the mobile fraction and the residual fraction might not release in the next cycling of compost addition and infiltration. The cumulative release of Cd, Cr, Cu, and Pb accounted for less than 5% of the total contents during four times of compost applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. The effect of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro.

    Science.gov (United States)

    Shehata, Awad A; Schrödl, Wieland; Aldin, Alaa A; Hafez, Hafez M; Krüger, Monika

    2013-04-01

    The use of glyphosate modifies the environment which stresses the living microorganisms. The aim of the present study was to determine the real impact of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro. The presented results evidence that the highly pathogenic bacteria as Salmonella Entritidis, Salmonella Gallinarum, Salmonella Typhimurium, Clostridium perfringens and Clostridium botulinum are highly resistant to glyphosate. However, most of beneficial bacteria as Enterococcus faecalis, Enterococcus faecium, Bacillus badius, Bifidobacterium adolescentis and Lactobacillus spp. were found to be moderate to highly susceptible. Also Campylobacter spp. were found to be susceptible to glyphosate. A reduction of beneficial bacteria in the gastrointestinal tract microbiota by ingestion of glyphosate could disturb the normal gut bacterial community. Also, the toxicity of glyphosate to the most prevalent Enterococcus spp. could be a significant predisposing factor that is associated with the increase in C. botulinum-mediated diseases by suppressing the antagonistic effect of these bacteria on clostridia.

  1. Functional characterization of aroA from Rhizobium leguminosarum with significant glyphosate tolerance in transgenic Arabidopsis.

    Science.gov (United States)

    Han, Jing; Tian, Yong-Sheng; Xu, Jing; Wang, Li-Juan; Wang, Bo; Peng, Ri-He; Yao, Quan-Hong

    2014-09-01

    Glyphosate is the active component of the top-selling herbicide, the phytotoxicity of which is due to its inhibition of the shikimic acid pathway. 5-Enolpyruvylshikimate-3-phosphate synthase (EPSPS) is a key enzyme in the shikimic acid pathway. Glyphosate tolerance in plants can be achieved by the expression of a glyphosate-insensitive aroA gene (EPSPS). In this study, we used a PCR-based two-step DNA synthesis method to synthesize a new aroA gene (aroAR. leguminosarum) from Rhizobium leguminosarum. In vitro glyphosate sensitivity assays showed that aroAR. leguminosarum is glyphosate tolerant. The new gene was then expressed in E. coli and key kinetic values of the purified enzyme were determined. Furthermore, we transformed the aroA gene into Arabidopsis thaliana by the floral dip method. Transgenic Arabidopsis with the aroAR. leguminosarum gene was obtained to prove its potential use in developing glyphosate-resistant crops.

  2. Germination test as a fast method to detect glyphosate-resistant sourgrass

    Directory of Open Access Journals (Sweden)

    Marcos Altomani Neves Dias

    2015-09-01

    Full Text Available The occurrence of weed species with different levels of resistance to glyphosate has increasingly spread in agricultural areas. In Brazil, sourgrass is among the main species presenting issues in this regard. Thus, fast and reliable methods to detect glyphosate resistance are of special interest for this specie, either for research or rational management purposes. This study was carried out to verify the feasibility of using the germination test to detect glyphosate resistance in sourgrass. The experiment was conducted with two sourgrass biotypes, with different levels of susceptibility to glyphosate. The seeds were previously imbibed in solutions composed of 0, 0.1875%, 0.25%, 0.75%, 1.5%, 3% and 6% of glyphosate during two periods, five and ten minutes, and submitted to germination tests. The results indicate the germination test as a feasible and time-saving approach to evaluate glyphosate-resistant sourgrass, with results available in seven days.

  3. Germination test as a fast method to detect glyphosate-resistant sourgrass

    Directory of Open Access Journals (Sweden)

    Marcos Altomani Neves Dias

    2015-01-01

    Full Text Available The occurrence of weed species with different levels of resistance to glyphosate has increasingly spread in agricultural areas. In Brazil, sourgrass is among the main species presenting issues in this regard. Thus, fast and reliable methods to detect glyphosate resistance are of special interest for this specie, either for research or rational management purposes. This study was carried out to verify the feasibility of using the germination test to detect glyphosate resistance in sourgrass. The experiment was conducted with two sourgrass biotypes, with different levels of susceptibility to glyphosate. The seeds were previously imbibed in solutions composed of 0, 0.1875%, 0.25%, 0.75%, 1.5%, 3% and 6% of glyphosate during two periods, five and ten minutes, and submitted to germination tests. The results indicate the germination test as a feasible and time-saving approach to evaluate glyphosate-resistant sourgrass, with results available in seven days.

  4. Inhibition effect of glyphosate on the acute and subacute toxicity of cadmium to earthworm Eisenia fetida.

    Science.gov (United States)

    Zhou, Chui-Fan; Wang, Yu-Jun; Sun, Rui-Juan; Liu, Cun; Fan, Guang-Ping; Qin, Wen-Xiu; Li, Cheng-Cheng; Zhou, Dong-Mei

    2014-10-01

    The acute and subacute toxicities of cadmium (Cd) to earthworm Eisenia fetida in the presence and absence of glyphosate were studied. Although Cd is highly toxic to E. fetida, the presence of glyphosate markedly reduced the acute toxicity of Cd to earthworm; both the mortality rate of the earthworms and the accumulation of Cd decreased with the increase of the glyphosate/Cd molar ratio. The subcellular distribution of Cd in E. fetida tissues showed that internal Cd was dominant in the intact cells fraction and the heat-stable proteins fraction. The presence of glyphosate reduced the concentration of Cd in all fractions, especially the intact cells. During a longer period of exposure, the weight loss of earthworm and the total Cd absorption was alleviated by glyphosate. Thus, the herbicide glyphosate can reduce the toxicity and bioavailability of Cd in the soil ecosystems at both short- and long-term exposures.

  5. Equilibrium and kinetic mechanisms of woody biochar on aqueous glyphosate removal.

    Science.gov (United States)

    Mayakaduwa, S S; Kumarathilaka, Prasanna; Herath, Indika; Ahmad, Mahtab; Al-Wabel, Mohammed; Ok, Yong Sik; Usman, Adel; Abduljabbar, Adel; Vithanage, Meththika

    2016-02-01

    We investigated the removal of aqueous glyphosate using woody (dendro) biochar obtained as a waste by product from bioenergy industry. Equilibrium isotherms and kinetics data were obtained by adsorption experiments. Glyphosate adsorption was strongly pH dependent occurring maximum in the pH range of 5-6. The protonated amino moiety of the glyphosate molecule at this pH may interact with π electron rich biochar surface via π-π electron donor-acceptor interactions. Isotherm data were best fitted to the Freundlich and Temkin models indicating multilayer sorption of glyphosate. The maximum adsorption capacity of dendro biochar for glyphosate was determined by the isotherm modeling to be as 44 mg/g. Adsorption seemed to be quite fast, reaching the equilibrium glyphosate removal.

  6. Glyphosate sorption and desorption in soils with distinct phosphorus levels

    Energy Technology Data Exchange (ETDEWEB)

    Prata, Fabio [BIOAGRI Labs., Piracicaba, SP (Brazil). Div. de Quimica. Lab. de Radioquimica; Cardinali, Vanessa Camponez do Brasil; Tornisielo, Valdemar Luiz; Regitano, Jussara Borges [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz. Dept. de Ciencias Exatas; Lavorenti, Arquimedes [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Secao de Toxicologia

    2003-03-01

    The sorption of glyphosate by soils occurs due to the inner sphere complex formation with metals of soil oxides, which are related to the soil phosphate adsorption capacity. The aim of this study was to evaluate the effects of increasing rates of phosphorus on sorption and desorption of glyphosate in three soils with different mineralogical attributes. Soils were a Rhodic Kandiudalf, an Anionic Acrudox and a Typic Humaquept. Soil samples were amended with Kh{sub 2}PO{sub 4} at equivalent rates of 0; 1,000; 5,000; 20,000 and 50,000 kg ha{sup -1} of P{sub 2}O{sub 5}, which are high from the agricultural point of view, but necessary in order to perform sorption and desorption studies. The experimental design consisted of a completely randomized factorial: 2 soils x 5 phosphorus rates and 3 replicates. For the sorption experiments, five glyphosate solutions were employed (0.42; 0.84; 1.68; 3.36 and 6.72 mg L{sup -1}), with a {sup 14}C radioactivity of 0.233 kBq mL{sup -1}. Four steps of the desorption procedures withCaCl{sub 2} 0.01 mol L{sup -1} and one extraction with Mehlich 3 were performed only at one concentration (0.84 mol L{sup -1}). Soil samples were afterwards biologically oxidized to establish the radioactive balance. Glyphosate competes with phosphorus for specific sorption sites, but this competition becomes important when phosphorus is present at rates higher than 1,000 mg dm{sup -3}. Moreover, a small amount of applied glyphosate was extracted (<10%), and the extraction increased with increasing soil phosphorus content. (author)

  7. Glyphosate sorption and desorption in soils with distinct phosphorus levels

    Directory of Open Access Journals (Sweden)

    Prata Fábio

    2003-01-01

    Full Text Available The sorption of glyphosate by soils occurs due to the inner sphere complex formation with metals of soil oxides, which are related to the soil phosphate adsorption capacity. The aim of this study was to evaluate the effects of increasing rates of phosphorus on sorption and desorption of glyphosate in three soils with different mineralogical attributes. Soils were a Rhodic Kandiudalf, an Anionic Acrudox and a Typic Humaquept. Soil samples were amended with KH2PO4 at equivalent rates of 0; 1,000; 5,000; 20,000 and 50,000 kg ha-1 of P2O5, which are high from the agricultural point of view, but necessary in order to perform sorption and desorption studies. The experimental design consisted of a completely randomized factorial: 2 soils x 5 phosphorus rates and 3 replicates. For the sorption experiments, five glyphosate solutions were employed (0.42; 0.84; 1.68; 3.36 and 6.72 mg L-1, with a 14C radioactivity of 0.233 kBq mL-1. Four steps of the desorption procedure with CaCl2 0.01 mol L-1 and one extraction with Mehlich 3 were performed only at one concentration (0.84 mol L-1. Soil samples were afterwards biologically oxidized to establish the radioactive balance. Glyphosate competes with phosphorus for specific sorption sites, but this competition becomes important when phosphorus is present at rates higher than 1,000 mg dm-3. Moreover, a small amount of applied glyphosate was extracted (<10%, and the extraction increased with increasing soil phosphorus content.

  8. Repeatability of Cryogenic Multilayer Insulation

    Science.gov (United States)

    Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

    2017-01-01

    Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between multiple identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five GRC provided coupons with 25 layers was shown to be +/- 8.4 whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0. A second group of 10 coupons have been fabricated by Yetispace and tested by Florida State University, through the first 4 tests, the repeatability has been shown to be +/- 16. Based on detailed statistical analysis, the data has been shown to be statistically significant.

  9. Can an aquatic macrophyte bioaccumulate glyphosate? Development of a new method of glyphosate extraction in Ludwigia peploides and watershed scale validation.

    Science.gov (United States)

    Pérez, Débora Jesabel; Okada, Elena; Menone, Mirta Luján; Costa, José Luis

    2017-10-01

    Glyphosate is intensively used in agricultural fields and it is frequently detected in non-target wetland ecosystems. The floating hydrophyte Ludwigia peploides is widely distributed in American streams and it is an abundant species. Therefore, our objectives were (1) to establish and validate an extraction and quantification methodology for glyphosate in L. peploides and (2) to evaluate the role of this species as a potential glyphosate biomonitor in an agricultural watershed. We developed a new method of glyphosate extraction from leaves of L. peploides. The method recovery was 117± 20% and the matrix effect 20%. To validate the method using environmental samples, plants of L. peploides were collected in March 2016 from eight monitoring sites of El Crespo stream. Surface water and sediment samples were collected at the same time to measure glyphosate and to calculate bioconcentration factors (BCFs) and biota-sediment accumulation factors (BSAFs). Glyphosate was detected in 94.11% in leaves, the concentrations ranging between 4 and 108 μg/kg. Glyphosate was detected in surface water and sediments at 75% and 100% of the samples, at concentrations that varied between 0 and 1.7 μg/L and 5-10.50 μg/kg dry weight, respectively. The mean BCFs and BSAFs were 88.10 L/Kg and 7.61, respectively. These results indicate that L. peploides bioaccumulates glyphosate mainly bioavailable in the surface water. In this sense, L. peploides could be used as a biomonitor organism to evaluate glyphosate levels in freshwater aquatic ecosystems because, in addition to its capacity to bioconcentrate glyphosate, it is easy to sample and it has a restricted mobility. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Effects of pH and phosphate on glyphosate adsorption to Argentina soils.

    Science.gov (United States)

    De Geronimo, Eduardo; Aparicio, Virginia; Costa, José Luis

    2017-04-01

    Glyphosate is a non-selective, post-emergence herbicide that is widely used in Argentina. Due to the similar molecular structures, glyphosate and phosphate compete for the same adsorption sites in soil. Soil pH has a strong influence in glyphosate and phosphate adsorption since it modifies the net charge of the molecules and, consequently, the force of the electrostatic interaction between these molecules and soil components. Glyphosate adsorption generally decreases as the soil pH was increased, although there were exceptions. In this work, we study the effects of pH and the presence of phosphate on the adsorption of glyphosate on s