WorldWideScience
1

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

Science.gov (United States)

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 o...

2

Sensibilidade de estirpes de Bradyrhizobium ao glyphosate Sensitivity of Bradyrhizobium strains to glyphosate  

Directory of Open Access Journals (Sweden)

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.Glyphosate applications to glyphosate-resistant soybean may impair symbiosis with Bradyrhizobium, a symbiotic bacterium. This study evaluated the sensitivity to glyphosate of three Bradyrhizobium strains used commercially in soybean crop in Brazil. The concentrations (0.0; 5.4; 10.8; 21.6 e 43.2 µg L-1 of the active ingredient glyphosate [N­(phosphonomethylglycine] were added to YM liquid medium for the growth of one strain of B. japonicum (SEMIA 5079 and two strains of B. elkanni (SEMIA 5019 and SEMIA 587 inoculated as pure culture. The herbicide effect on the growth of the tested strains was assessed by optical density and growth curves were established for each strain. Reduction in growth of strains in the lowest glyphosate concentration were 18% for SEMIA 5079, 29% for SEMIA 5019 and 35% for SEMIA 587. In general, the higher the concentration of the herbicide in the culture medium, the greater the growth inhibition. The strains showed differential sensitivity only at the lowest concentrations of glyphosate, allowing the determination of the following order of sensitivity: SEMIA 587>SEMIA 5019>SEMIA 5079. This differential sensitivity is dependent on the herbicide concentration, since in the presence of 43.2 µg L-1 all strains severely reduced growth, not showing difference among them.

Rodrigo Josemar Seminoti Jacques

2010-02-01

3

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

Science.gov (United States)

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.

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

2014-05-01

4

Sensibilidade de estirpes de Bradyrhizobium ao glyphosate / Sensitivity of Bradyrhizobium strains to glyphosate  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 Brasi [...] l. 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. Abstract in english Glyphosate applications to glyphosate-resistant soybean may impair symbiosis with Bradyrhizobium, a symbiotic bacterium. This study evaluated the sensitivity to glyphosate of three Bradyrhizobium strains used commercially in soybean crop in Brazil. The concentrations (0.0; 5.4; 10.8; 21.6 e 43.2 µg [...] L-1) of the active ingredient glyphosate [N­(phosphonomethyl)glycine] were added to YM liquid medium for the growth of one strain of B. japonicum (SEMIA 5079) and two strains of B. elkanni (SEMIA 5019 and SEMIA 587) inoculated as pure culture. The herbicide effect on the growth of the tested strains was assessed by optical density and growth curves were established for each strain. Reduction in growth of strains in the lowest glyphosate concentration were 18% for SEMIA 5079, 29% for SEMIA 5019 and 35% for SEMIA 587. In general, the higher the concentration of the herbicide in the culture medium, the greater the growth inhibition. The strains showed differential sensitivity only at the lowest concentrations of glyphosate, allowing the determination of the following order of sensitivity: SEMIA 587>SEMIA 5019>SEMIA 5079. This differential sensitivity is dependent on the herbicide concentration, since in the presence of 43.2 µg L-1 all strains severely reduced growth, not showing difference among them.

Rodrigo Josemar Seminoti, Jacques; Sérgio de Oliveira, Procópio; José Barbosa dos, Santos; Maria Catarina Megumi, Kasuya; Antônio Alberto da, Silva.

2010-02-01

5

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

Directory of Open Access Journals (Sweden)

Full Text Available Avaliou-se a resposta de nove cultivares de algodoeiro, de importância econômica no Estado do Mato Grosso, quanto à intoxicação causada por subdoses de glyphosate. Os cultivares de algodoeiro utilizados foram Fabrika, Makina, ITA-90, FM 986, FM 966, Delta Opal, BRS Facual, Antares e Coodetec 407. As plantas foram cultivadas em tubetes preenchidos com substrato de solo e mantidas em casa telada, tendo recebido a aplicação do glyphosate aos 20 dias após a emergência, época em que apresentavam quatro folhas verdadeiras. As subdoses de glyphosate, simulando deriva, foram de 270 e 540 g ha-1. Também foi utilizada testemunha, sem aplicação do herbicida, para efeito de comparação. Foram realizadas avaliações semanais até 42 dias após a aplicação dos tratamentos (DAA, período em que também foi tomada a altura das plantas. Os sintomas visuais de intoxicação iniciaram-se aos 3 DAA, caracterizados pelo amarelecimento das pontas das folhas mais novas, seguido de murchamento do ápice das plantas. Na dose de 270 g ha-1 esses sintomas foram de baixa intensidade, mas a 540 g ha-1 causaram, na maioria dos casos, toxidez "preocupante" a "muito alta". Os cultivares BRS Facual e FM 986 mostraram-se os mais suscetíveis. A altura das plantas foi mais afetada quando se aplicou a menor dose de glyphosate. Houve recuperação de todos os cultivares tratados com 270 g ha-1 de glyphosate até os 42 DAA. Quando tratados com 540 g ha-1 de glyphosate, os cultivares Fabrika, Coodetec 407, BRS-Facual e ITA-90 foram mais sensíveis, apresentando redução de altura entre 84 e 90% aos 42 DAA. Os cultivares menos sensíveis na dose de 270 g ha-1 de glyphosate não foram os mesmos para a dose de 540 g ha-1.The response of nine cotton cultivars economically important in the state of Mato Grosso was evaluated in relation to the toxicity caused by reduced rates of glyphosate. The cotton cultivars used were Fabrika, Makina, ITA-90, FM 986, FM 966, Delta Opal, 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.

O.M. Yamashita

2005-12-01

6

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

Science.gov (United States)

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. PMID:17177536

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

2006-12-27

7

Influência de doses reduzidas do glyphosate no tomateiro (Lycopersicon esculentum) / Influence of reduced glyphosate rates on tomato plant (Lycopersicon esculentum Mill.)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O tomateiro (Lycopersicon esculentum) é cultivado em todas as regiões do Brasil devido à ampla utilização na culinária, tanto in natura quanto industrializado. A deriva do glyphosate vem sendo citada como um dos fatores que interferem negativamente sobre as culturas hortícolas, cultivadas nas adjacê [...] ncias das lavouras de arroz. Objetivou-se com esse verificar os efeitos de doses reduzidas do glyphosate sobre a cultura do tomateiro. O glyphosate foi aplicado a 0, 15, 30, 45, 60, 75 e 90% da dose de 1.260 g ha-1, aos 30, 50 e 70 dias após o transplante (DAT) da cultura. As variáveis analisadas foram fitotoxicidade, altura e número de cachos florais, flores e frutos por planta. Os dados experimentais foram submetidos à análise da variância e, sendo significativos, os efeitos de época de aplicação foram comparados pelo teste de Tukey, e os efeitos do fator dose, analisados por regressão. A aplicação do glyphosate, a partir de 378 g ha-1, afetou o desenvolvimento do tomateiro, independentemente do estádio de desenvolvimento. Abstract in english Tomato plant (Lycopersicon esculentum) is grown in all regions in Brazil since it is widely used in cooking, processed or fresh. Glyphosate drift has been found rcited as one of the factors interfering negatively in vegetables cultivated in areas adjacent to rice plantations. The objective of this s [...] tudy was to evaluate the effects of reduced rates of glyphosate on tomato plants, applied at of 0, 15, 30, 45, 60, 75 and 90% of the commercial dose (1.260 g ha-1) 30, 50 and 70 days after transplanting (DAT) the tomato plants. The variables analyzed were: phytotoxicity, plant height, number of flowering clusters, and flower and fruits/plant. The data were submitted to analysis of variance, the Tukey test and regression. Glyphosate application at rates higher than 378 g ha-1 affected the growth of the tomato plants negatively, regardless of their development stage.

S.S., Fiqueredo; A.E., Loeck; M.D., Rosenthal; D., Agostinetto; L.C., Fontana; R.P., Rigoli.

2007-12-01

8

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

OpenAIRE

Avaliou-se a resposta de nove cultivares de algodoeiro, de importância econômica no Estado do Mato Grosso, quanto à intoxicação causada por subdoses de glyphosate. Os cultivares de algodoeiro utilizados foram Fabrika, Makina, ITA-90, FM 986, FM 966, Delta Opal, BRS Facual, Antares e Coodetec 407. As plantas foram cultivadas em tubetes preenchidos com substrato de solo e mantidas em casa telada, tendo recebido a aplicação do glyphosate aos 20 dias após a emergência, época em que apre...

Yamashita, O. M.; Guimara?es, S. C.

2005-01-01

9

Anatomia foliar de Lolium multiflorum sensível e resistente ao glyphosate Leaf anatomy of Lolium multiflorum sensitive and resistant to glyphosate  

OpenAIRE

Este trabalho foi desenvolvido com o intuito de contribuir para o conhecimento anatômico da espécie Lolium multiflorum e, a partir disso, observar possíveis alterações que possam elucidar o mecanismo que confere resistência ao herbicida glyphosate. Para isso, realizou-se um experimento com quatro biótipos dessa espécie com distinta sensibilidade ao herbicida glyphosate, sendo um sensível (B1S) e três resistentes (B2R, B3R e B4R). As análises ocorreram a partir de secções transver...

Galvani, J.; Rizzardi, M. A.; Carneiro, C. M.; Bianchi, M. A.

2012-01-01

10

Qualidade de sementes de algodão provenientes de plantas tratadas com doses reduzidas de glyphosate Quality of cotton seeds from plants submitted to reduced rates of glyphosate  

Directory of Open Access Journals (Sweden)

Full Text Available O presente trabalho teve como objetivo avaliar a influência do tratamento de plantas de algodoeiro com doses reduzidas de glyphosate, simulando deriva, na qualidade das sementes produzidas. Plantas dos cultivares ITA-90 e BRS-Facual foram tratadas em dois diferentes estádios de desenvolvimento (quatro e dez folhas com as doses de 0, 180 e 360 g ha-1 de glyphosate. Avaliaram-se o rendimento de algodão em caroço, a qualidade das sementes, através de massa de 100 sementes, a porcentagem de emergência e a massa seca de plântulas emersas. Houve redução no rendimento de algodão em caroço em todos os tratamentos, exceto em plantas mais velhas tratadas com 180 g ha-1, sem afetar a qualidade das sementes.This work aimed to evaluate the influence of cotton plant treatment using reduced rates of glyphosate, simulating drift, on the quality of the seeds produced. The plants of the ITA-90 and BRS-Facual cultivars were treated at two different development stages (4 and 10 leaves with glyphosate in the doses of 0; 180 and 360 g ha-1 ea. Cotton crop yield was evaluated. The material was seeded and seed quality evaluated, through mass of 100 seeds, emergence percentage and mass of plantules. There was a reduction in cotton production in the treatments, except in older plants treated with 180 g ha-1. No significant difference in plantule emergence was found in the different treatments.

O.M. Yamashita

2006-06-01

11

Efeito de doses reduzidas de glyphosate e paraquat simulando deriva na cultura do milho Effect of reduced rates of glyphosate and paraquat simulating drift in corn crop  

Directory of Open Access Journals (Sweden)

Full Text Available A aplicação de herbicidas, seja para a dissecação de culturas ou para o controle de plantas daninhas, vem crescendo, devido a expansão da fronteira agrícola brasileira. Esse fato aumenta os riscos de ocorrência de deriva acidental em culturas vizinhas suscetíveis. As perdas em produtividade são desconhecidas em muitas situações de ocorrência de deriva de herbicidas. O objetivo deste trabalho foi avaliar a possível toxicidade causada pela deriva de doses reduzidas de dois herbicidas (glyphosate e paraquat no período inicial de desenvolvimento da cultura do milho. Foram utilizadas cinco doses simulando deriva - 2, 4, 6, 8 e 12% da dose recomendada (1.440 g ha-1 de glyphosate e 400 g ha-1 de paraquat - sobre o cultivar de milho híbrido triplo BRS 3123. No florescimento, foram avaliados altura da planta, área foliar, peso da matéria seca, teor de clorofila e sintomas visuais de injúria. Na colheita, avaliaram-se estande final, peso de espigas, peso de 1.000 grãos e produção de grãos. A altura das plantas, a área foliar e o peso da matéria seca não foram afetados pelo efeito das derivas nos dois anos agrícolas (1996/97 e 1997/98, exceto pela área foliar, que em 1997/98 sofreu redução, sobretudo no tratamento com 12% da dose normal de glyphosate. De maneira geral, os resultados obtidos para as demais características foram semelhantes nos dois anos de condução do ensaio. O teor de clorofila nas folhas e o estande final não foram afetados pelas doses reduzidas. O grau de toxicidade, avaliado por meio de plantas injuriadas pela deriva, aos 7, 14 e 21 dias após a aplicação dos herbicidas, apresentou diferenças significativas. Os maiores danos foram observados com a maior subdose simulando deriva dos herbicidas. O peso de 1.000 grãos não foi afetado, ao passo que a produção de espigas e de grãos foi severamente prejudicada. Observou-se que a deriva simulada dos herbicidas em altas concentrações afetou o desenvolvimento das plantas e reduziu a produção de grãos. Já a aplicação em baixas concentrações (2 a 4% não afetou o desenvolvimento das plantas nem tampouco a produtividade.Herbicide application has increased considerably in the Brazilian agriculture over the last years, either for weed management or crop desiccation. The intensive use of herbicide shas brought risks of drift in sensitive neighbor crops. Drift effects on crops susceptible to herbicides is not well quantified in several situations. The objective of this study was to evaluate the injuries caused by simulated herbicide drift on the initial phase of growth of the maize crop. Two herbicides with five concentrations of simulated drift were used: 2, 4, 6, 8 and 12% of the recommended rate (1,440 g ha-1 of glyphosate and 400 g ha-1 of paraquat, sprayed over the top foliage of the maize triple hybrid BRS 3123. Plant height, leaf area, dry weight, leaf chlorophyll content and visual symptoms of injury were evaluated at flowering time. Final stand, ear weight, 1,000 grains weight and grain production. Plant height, leaf area, leaf chlorophyll content and dry weight were not affected by simulated drifts in both years (1996/97 and 1997/98, except the leaf area in 1997/98, which had a reduction especially in the treatment where 12% of the glyphosate rate was used. In general, the results for the other traits were similar in both years in which the trials were carried out. At harvesting time, final stand and weight of 1,000 grains were not affected by simulated drifts, whereas ear weight and grain production were severely affected. The degree of visual injuries evaluated through percentage of plants injured by drift at 7, 14 and 21 days after herbicide application showed significant differences. The major damages were observed with the greater dosage of simulated drift. Weight of 1,000 grains was not affected, whereas ears and grain production were severely affected. Herbicide drift in high concentrations affected the plant development and reduced grain production while application of glyphosate and paraqu

P.C. Magalhães

2001-08-01

12

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

Directory of Open Access Journals (Sweden)

Full Text Available O consumo de madeira no Brasil e no mundo apresenta demanda crescente. Em confronto com a pressão ambientalista de manutenção das florestas nativas, há necessidade de se estabelecerem áreas de reflorestamento para suprir o aumento da demanda de madeira, com a utilização de formas de manejo e tratos culturais que permitam o pleno crescimento das essências florestais. Um dos principais problemas do manejo de reflorestamento é a interferência das plantas daninhas após o plantio das mudas no campo, sendo o uso de herbicidas a principal forma de manejo. Este trabalho teve o objetivo de avaliar a eficiência de doses crescentes de glyphosate em mudas de varjão em condições de ambiente protegido. Foram avaliadas as doses de 0, 90, 180, 360 e 720 g ha-1 de glyphosate em plantas com quatro meses de idade, observando a intoxicação das plantas, altura, diâmetro do caule e número de folhas. O varjão, nas condições do experimento, apresentou tolerância e recuperação ao glyphosate até a dose de 360 g ha-1. Doses superiores a esta retardaram o crescimento da planta. O prejuízo causado pela deriva de glyphosate nessas plantas foi diretamente proporcional ao aumento da dose. Os sintomas evoluíram para queda de folhas, comprometendo o crescimento das plantas.Wood consumption has significantly increased in Brazil and worldwide.The environmental pressure to preserve native forest led to the need to establish reforestation areas to meet the increasing wood demand by applying cultural practices and management allowing a total growth of forest trees. One of the main problems in reforestation management is weed competition after seedling planting, with herbicide use being the main form of management. The objective of this work was to evaluate the phytotoxic effect of increasing rates of glyphosate on Varjão seedlings, under greenhouse conditions. Concentrations of 90, 180, 360 and 720 g ha-1 of glyphosate were evaluated in four-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.

O.M. Yamashita

2006-09-01

13

Target site mutation and reduced translocation are present in a glyphosate-resistant Lolium multiflorum Lam. biotype from Spain.  

Science.gov (United States)

The resistance mechanism of a glyphosate-resistant Lolium multiflorum Lam. biotype collected in Córdoba (Southern Spain) was examined. Resistance Factor values at three different growth stages ranged between 4.77 and 4.91. At 96 hours after treatment (HAT) the S biotype had accumulated seven times more shikimic acid than the R biotype. There were significant differences in translocation of (14)C-glyphosate between biotypes, i.e. at 96 HAT, the R biotype accumulated in the treated leaf more than 70% of the absorbed herbicide, in comparison with 59.21% of the S biotype; the R biotype translocated only 14.79% of the absorbed (14)C-glyphosate to roots, while in the S population this value was 24.79%. Visualization of (14)C-glyphosate by phosphor imaging showed a reduced distribution in the R biotype compared with the S. Glyphosate metabolism was not involved in the resistance mechanism due to both biotypes showing similar values of glyphosate at 96 HAT. Comparison of the EPSPS gene sequences between biotypes indicated that the R biotype has a proline 182 to serine amino acid substitution. In short, the resistance mechanism of the L. multiflorum Lam. biotype is due to an impaired translocation of the herbicide and an altered target site. PMID:22771431

González-Torralva, Fidel; Gil-Humanes, Javier; Barro, Francisco; Brants, Ivo; De Prado, Rafael

2012-09-01

14

TREATABILITY STUDIES OF PESTICIDE MANUFACTURING WASTEWATERS: GLYPHOSATE  

Science.gov (United States)

The report gives results of subjecting various combinations of glyphosate production wastestreams to biological treatment following lime-pretreatment to reduce high levels of glyphosate. Bench-scale biological treatment demonstrated that glyphosate did not appear to interfere wit...

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A aplicação de herbicidas, seja para dessecação de culturas ou para controle de plantas daninhas, vem crescendo, devido à expansão da fronteira agrícola brasileira. Esse fato aumenta os riscos de ocorrência de deriva acidental em culturas vizinhas suscetíveis; no entanto, as perdas em produtividade [...] dessas culturas são desconhecidas em muitas situações de ocorrência de deriva de herbicidas. O objetivo deste trabalho foi avaliar a fitotoxicidade causada por doses reduzidas dos herbicidas glyphosate e paraquat simulando deriva, bem como seus efeitos, no desenvolvimento das plantas e no rendimento de grãos de sorgo. O estudo foi conduzido durante os anos agrícolas 1996/97 e 1997/98, utilizando-se o híbrido BR 700 no delineamento de blocos ao acaso, com 12 tratamentos e quatro repetições. Foram utilizadas cinco doses reduzidas simulando deriva - 2, 4, 6, 8 e 12% da dose recomendada (dose recomendada: 1.440 g ha-1 de glyphosate e 400 g ha-1 de paraquat) - e duas testemunhas sem aplicação de herbicidas para comparação. Área foliar e peso da matéria seca não foram afetados pelos tratamentos de deriva, ao passo que a altura da planta foi reduzida sobretudo nas maiores doses dos herbicidas. O teor de clorofila foi afetado apenas no ano agrícola 1997/98, ocorrendo maior porcentagem de injúrias à medida que se aumentou a concentração de deriva. No ano agrícola 1996/97, os danos observados na parte aérea foram maiores e o estande final chegou a ser reduzido pela maior dose de glyphosate. Com relação à produtividade, somente no ano agrícola 1996/97 houve redução devido à deriva, em que a maior concentração de glyphosate resultou em menor peso de panículas e de grãos. No ano agrícola 1997/98, não houve efeito de deriva nas características de produção, em razão, provavelmente, da influência de fatores climáticos. O sorgo é uma planta sensível à ação de herbicidas não-seletivos; doses reduzidas, tanto de 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. Abstract in english 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 d

P.C., Magalhães; J.B., Silva; F.O.M., Durães; D., Karam; L.S., Ribeiro.

2001-08-01

16

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)

Full Text Available A aplicação de herbicidas, seja para dessecação de culturas ou para controle de plantas daninhas, vem crescendo, devido à expansão da fronteira agrícola brasileira. Esse fato aumenta os riscos de ocorrência de deriva acidental em culturas vizinhas suscetíveis; no entanto, as perdas em produtividade dessas culturas são desconhecidas em muitas situações de ocorrência de deriva de herbicidas. O objetivo deste trabalho foi avaliar a fitotoxicidade causada por doses reduzidas dos herbicidas glyphosate e paraquat simulando deriva, bem como seus efeitos, no desenvolvimento das plantas e no rendimento de grãos de sorgo. O estudo foi conduzido durante os anos agrícolas 1996/97 e 1997/98, utilizando-se o híbrido BR 700 no delineamento de blocos ao acaso, com 12 tratamentos e quatro repetições. Foram utilizadas cinco doses reduzidas simulando deriva - 2, 4, 6, 8 e 12% da dose recomendada (dose recomendada: 1.440 g ha-1 de glyphosate e 400 g ha-1 de paraquat - e duas testemunhas sem aplicação de herbicidas para comparação. Área foliar e peso da matéria seca não foram afetados pelos tratamentos de deriva, ao passo que a altura da planta foi reduzida sobretudo nas maiores doses dos herbicidas. O teor de clorofila foi afetado apenas no ano agrícola 1997/98, ocorrendo maior porcentagem de injúrias à medida que se aumentou a concentração de deriva. No ano agrícola 1996/97, os danos observados na parte aérea foram maiores e o estande final chegou a ser reduzido pela maior dose de glyphosate. Com relação à produtividade, somente no ano agrícola 1996/97 houve redução devido à deriva, em que a maior concentração de glyphosate resultou em menor peso de panículas e de grãos. No ano agrícola 1997/98, não houve efeito de deriva nas características de produção, em razão, provavelmente, da influência de fatores climáticos. O sorgo é uma planta sensível à ação de herbicidas não-seletivos; doses reduzidas, tanto de 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 effect on the productivity characteristics probably due to climate factors. The sorghum pl

P.C. Magalhães

2001-08-01

17

Aspectos morfofisiológicos de biótipos de azevém (Lolium multiflorum) sensíveis e resistentes ao glyphosate / Morphophysiological aspects of ryegrass biotypes (Lolium multiflorum) sensitive and resistant to glyphosate  

Scientific Electronic Library Online (English)

Full Text Available O azevém é uma gramínea com elevado potencial de infestação em lavouras e pomares, e seu controle com glyphosate tem sido limitado devido à existência de biótipos resistentes a esse herbicida. Objetivou-se comparar quatro biótipos de azevém coletados em diferentes regiões do Rio Grande do Sul, com o [...] intuito de testar a hipótese de que aspectos morfofisiológicos e fenológicos estejam vinculados à resistência. O experimento foi conduzido em casa de vegetação, onde um biótipo suscetível (B1S, Passo Fundo) e três resistentes ao glyphosate (B2R, Santa Maria; B3R, Júlio de Castilhos; e B4R, Vacaria) foram colhidos aos 126, 147, 168 e 189 dias de idade. O biótipo B1S mostrou 21 dias de antecipação no florescimento em relação aos demais biótipos. O biótipo B4R produziu significativamente mais folhas (43 por planta), afilhos (14 por planta), espigas (14 por planta), sementes (3.484 por planta) e matéria seca total (raízes + parte aérea = 13,8 g por planta). Conclui-se que biótipos sensíveis não podem ser diferidos de biótipos resistentes apenas por aspectos morfológicos relacionados ao vigor. Abstract in english Ryegrass has a high potential for infestation in crops and orchads and its control with glyphosate has been limited due to the existence of herbicide-resistant biotypes. The objective of this work was to compare four ryegrass biotypes collected from different regions in the state of Rio Grande do Su [...] l, Brazil, to test the hypothesis that morphophysiological aspects and phenology are linked to resistance. The experiment was conducted in a greenhouse, where four biotypes, one susceptible (B1S, Passo Fundo) and three resistant to glyphosate (B2R, Santa Maria; B3R, Julio de Castillos; B4R, Vacaria) were collected at 126, 147, 168 and 189 days of age. Biotype B1S showed 21 days in advance of flowering in relation to the other biotypes. Biotype B4R produced significantly more leaves (43 per plant), tillers (14 per plant), ears (14 per plant), seeds (3484 per plant) and total dry matter (roots + shoot = 13.8 g per plant). It is concluded that sensitive biotypes cannot be distinguished from the resistant ones only by morphological aspects related to vigor.

J, Galvan; M.A, Rizzardi; S, Scheffer-Basso.

1107-11-01

18

Aspectos morfofisiológicos de biótipos de azevém (Lolium multiflorum sensíveis e resistentes ao glyphosate Morphophysiological aspects of ryegrass biotypes (Lolium multiflorum sensitive and resistant to glyphosate  

Directory of Open Access Journals (Sweden)

Full Text Available O azevém é uma gramínea com elevado potencial de infestação em lavouras e pomares, e seu controle com glyphosate tem sido limitado devido à existência de biótipos resistentes a esse herbicida. Objetivou-se comparar quatro biótipos de azevém coletados em diferentes regiões do Rio Grande do Sul, com o intuito de testar a hipótese de que aspectos morfofisiológicos e fenológicos estejam vinculados à resistência. O experimento foi conduzido em casa de vegetação, onde um biótipo suscetível (B1S, Passo Fundo e três resistentes ao glyphosate (B2R, Santa Maria; B3R, Júlio de Castilhos; e B4R, Vacaria foram colhidos aos 126, 147, 168 e 189 dias de idade. O biótipo B1S mostrou 21 dias de antecipação no florescimento em relação aos demais biótipos. O biótipo B4R produziu significativamente mais folhas (43 por planta, afilhos (14 por planta, espigas (14 por planta, sementes (3.484 por planta e matéria seca total (raízes + parte aérea = 13,8 g por planta. Conclui-se que biótipos sensíveis não podem ser diferidos de biótipos resistentes apenas por aspectos morfológicos relacionados ao vigor.Ryegrass has a high potential for infestation in crops and orchads and its control with glyphosate has been limited due to the existence of herbicide-resistant biotypes. The objective of this work was to compare four ryegrass biotypes collected from different regions in the state of Rio Grande do Sul, Brazil, to test the hypothesis that morphophysiological aspects and phenology are linked to resistance. The experiment was conducted in a greenhouse, where four biotypes, one susceptible (B1S, Passo Fundo and three resistant to glyphosate (B2R, Santa Maria; B3R, Julio de Castillos; B4R, Vacaria were collected at 126, 147, 168 and 189 days of age. Biotype B1S showed 21 days in advance of flowering in relation to the other biotypes. Biotype B4R produced significantly more leaves (43 per plant, tillers (14 per plant, ears (14 per plant, seeds (3484 per plant and total dry matter (roots + shoot = 13.8 g per plant. It is concluded that sensitive biotypes cannot be distinguished from the resistant ones only by morphological aspects related to vigor.

J Galvan

2011-01-01

19

Efeito de doses reduzidas de glyphosate e paraquat simulando deriva na cultura do milho / Effect of reduced rates of glyphosate and paraquat simulating drift in corn crop  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A aplicação de herbicidas, seja para a dissecação de culturas ou para o controle de plantas daninhas, vem crescendo, devido a expansão da fronteira agrícola brasileira. Esse fato aumenta os riscos de ocorrência de deriva acidental em culturas vizinhas suscetíveis. As perdas em produtividade são desc [...] onhecidas em muitas situações de ocorrência de deriva de herbicidas. O objetivo deste trabalho foi avaliar a possível toxicidade causada pela deriva de doses reduzidas de dois herbicidas (glyphosate e paraquat) no período inicial de desenvolvimento da cultura do milho. Foram utilizadas cinco doses simulando deriva - 2, 4, 6, 8 e 12% da dose recomendada (1.440 g ha-1 de glyphosate e 400 g ha-1 de paraquat) - sobre o cultivar de milho híbrido triplo BRS 3123. No florescimento, foram avaliados altura da planta, área foliar, peso da matéria seca, teor de clorofila e sintomas visuais de injúria. Na colheita, avaliaram-se estande final, peso de espigas, peso de 1.000 grãos e produção de grãos. A altura das plantas, a área foliar e o peso da matéria seca não foram afetados pelo efeito das derivas nos dois anos agrícolas (1996/97 e 1997/98), exceto pela área foliar, que em 1997/98 sofreu redução, sobretudo no tratamento com 12% da dose normal de glyphosate. De maneira geral, os resultados obtidos para as demais características foram semelhantes nos dois anos de condução do ensaio. O teor de clorofila nas folhas e o estande final não foram afetados pelas doses reduzidas. O grau de toxicidade, avaliado por meio de plantas injuriadas pela deriva, aos 7, 14 e 21 dias após a aplicação dos herbicidas, apresentou diferenças significativas. Os maiores danos foram observados com a maior subdose simulando deriva dos herbicidas. O peso de 1.000 grãos não foi afetado, ao passo que a produção de espigas e de grãos foi severamente prejudicada. Observou-se que a deriva simulada dos herbicidas em altas concentrações afetou o desenvolvimento das plantas e reduziu a produção de grãos. Já a aplicação em baixas concentrações (2 a 4%) não afetou o desenvolvimento das plantas nem tampouco a produtividade. Abstract in english Herbicide application has increased considerably in the Brazilian agriculture over the last years, either for weed management or crop desiccation. The intensive use of herbicide shas brought risks of drift in sensitive neighbor crops. Drift effects on crops susceptible to herbicides is not well quan [...] tified in several situations. The objective of this study was to evaluate the injuries caused by simulated herbicide drift on the initial phase of growth of the maize crop. Two herbicides with five concentrations of simulated drift were used: 2, 4, 6, 8 and 12% of the recommended rate (1,440 g ha-1 of glyphosate and 400 g ha-1 of paraquat), sprayed over the top foliage of the maize triple hybrid BRS 3123. Plant height, leaf area, dry weight, leaf chlorophyll content and visual symptoms of injury were evaluated at flowering time. Final stand, ear weight, 1,000 grains weight and grain production. Plant height, leaf area, leaf chlorophyll content and dry weight were not affected by simulated drifts in both years (1996/97 and 1997/98), except the leaf area in 1997/98, which had a reduction especially in the treatment where 12% of the glyphosate rate was used. In general, the results for the other traits were similar in both years in which the trials were carried out. At harvesting time, final stand and weight of 1,000 grains were not affected by simulated drifts, whereas ear weight and grain production were severely affected. The degree of visual injuries evaluated through percentage of plants injured by drift at 7, 14 and 21 days after herbicide application showed significant differences. The major damages were observed with the greater dosage of simulated drift. Weight of 1,000 grains was not affected, whereas ears and grain production were severely affected. Herbicide drift in high concentrations a

P.C., Magalhães; J.B., Silva; F.O.M., Durães; D., Karam; L.S., Ribeiro.

2001-08-01

20

Nitrogen Metabolism and Seed Composition as Influenced by Glyphosate Application in Glyphosate-Resistant Soybean  

Science.gov (United States)

Our previous research demonstrated that glyphosate drift affected nitrogen fixation and nitrogen assimilation in glyphosate-sensitive soybean at early growth stage. The objective of the present study was to investigate the effects of glyphosate application (Gly) of 1.12 kg ae ha-1 and 3.36 kg ae ka...

21

Root-zone glyphosate exposure adversely affects two ditch species.  

Science.gov (United States)

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. PMID:24833234

Saunders, Lyndsay E; Koontz, Melissa B; Pezeshki, Reza

2013-01-01

22

Evaluation of 2,4-D Amine, Glyphosate, 2,4-D Amine plus Glyphosate DMA and 2,4-D Choline/Glyphosate DMA for Their Efficacy on Glyphosate Susceptible and Resistant Canada Fleabane Populations  

OpenAIRE

The 2,4-D choline/glyphosate DMA formulation has reduced drift and volatility compared to the amine or ester formulation of 2,4-D and therefore is advantageous compared to a tank mix of 2,4-D amine or ester with glyphosate. The objective of this research was to compare the control of glyphosate susceptible and glyphosate resistant Canada fleabane with 2,4-D choline/glyphosate DMA with 2,4-D amine, glyphosate, and a tank mix of 2,4-D amine and glyphosate. Ten rates of 2,...

Laura Ford; Nader Soltani; Robinson, Darren E.; Nurse, Robert E.; Allan McFadden; Sikkema, Peter H.

2014-01-01

23

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

OpenAIRE

A alface-d'água (Pistia stratiotes) é uma das principais entre as macrófitas aquáticas que causam problemas em corpos hídricos no Brasil e são consideradas como plantas daninhas. O presente trabalho foi realizado com os objetivos de conhecer melhor a variabilidade genética dessa macrófita e relacionar essa variabilidade com a resposta à aplicação do herbicida glyphosate. Para isso, foram coletados indivíduos em 12 corpos hídricos em diferentes cidades do território nacional (Ame...

Ci?cero, E. A. S.; Pitelli, R. A.; Sena, J. A. D.; Ferraudo, A. S.

2007-01-01

24

Aspectos morfofisiológicos de biótipos de azevém (Lolium multiflorum) sensíveis e resistentes ao glyphosate Morphophysiological aspects of ryegrass biotypes (Lolium multiflorum) sensitive and resistant to glyphosate  

OpenAIRE

O azevém é uma gramínea com elevado potencial de infestação em lavouras e pomares, e seu controle com glyphosate tem sido limitado devido à existência de biótipos resistentes a esse herbicida. Objetivou-se comparar quatro biótipos de azevém coletados em diferentes regiões do Rio Grande do Sul, com o intuito de testar a hipótese de que aspectos morfofisiológicos e fenológicos estejam vinculados à resistência. O experimento foi conduzido em casa de vegetação, onde um biótipo ...

Galvan, J.; Rizzardi, M. A.; Scheffer-basso, S.

2011-01-01

25

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

Scientific Electronic Library Online (English)

Full Text Available A alface-d'água (Pistia stratiotes) é uma das principais entre as macrófitas aquáticas que causam problemas em corpos hídricos no Brasil e são consideradas como plantas daninhas. O presente trabalho foi realizado com os objetivos de conhecer melhor a variabilidade genética dessa macrófita e relacion [...] ar essa variabilidade com a resposta à aplicação do herbicida glyphosate. Para isso, foram coletados indivíduos em 12 corpos hídricos em diferentes cidades do território nacional (Americana, Cambaratiba, Curitiba, Itapura, Jaboticabal, Lagoa Santa, Piraí, Rio Grande, Rubinéia, Salto Grande, Santa Gertrudes e Três Lagoas). Os acessos foram caracterizados pelo uso de marcadores RAPD (DNA Polimórfico Amplificado ao Acaso), que permitiram, com o auxílio de iniciadores aleatórios, a caracterização dos locos polimórficos identificados por uma matriz de ausência e presença de bandas. Utilizando essa matriz, a análise de agrupamento permitiu nítida classificação dos acessos em três grupos com diferenças genéticas entre eles. Um ensaio de controle químico, com plantas mantidas em vasos plásticos (5 L) e pulverizadas com o herbicida glyphosate nas concentrações de 0,0, 0,6, 1,2, 1,8 e 2,4 kg ha-1, identificou, utilizando avaliações aos 7, 14 e 21 dias após aplicação, que as duas maiores doses promoveram melhor efeito herbicida. Foi verificado também que os acessos de Curitiba e Cambaratiba apresentaram menor suscetibilidade ao herbicida glyphosate. Não houve correspondência entre a estrutura de grupos dos acessos pela análise multivariada de agrupamento com a técnica RAPD e a suscetibilidade da alface-d'água ao glyphosate. Abstract in english Water lettuce (Pistia stratiotes) is one the most important macrophytes, classified as weed and causing serious problems in watercourses in Brazil. The aim of this research was to evaluate the genetic variability of water lettuce and its relationship with this plant's susceptibility to glyphosate. P [...] lant 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.

E.A.S., Cícero; R.A., Pitelli; J.A.D., Sena; A.S., Ferraudo.

2007-09-01

26

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)

Full Text Available A alface-d'água (Pistia stratiotes é uma das principais entre as macrófitas aquáticas que causam problemas em corpos hídricos no Brasil e são consideradas como plantas daninhas. O presente trabalho foi realizado com os objetivos de conhecer melhor a variabilidade genética dessa macrófita e relacionar essa variabilidade com a resposta à aplicação do herbicida glyphosate. Para isso, foram coletados indivíduos em 12 corpos hídricos em diferentes cidades do território nacional (Americana, Cambaratiba, Curitiba, Itapura, Jaboticabal, Lagoa Santa, Piraí, Rio Grande, Rubinéia, Salto Grande, Santa Gertrudes e Três Lagoas. Os acessos foram caracterizados pelo uso de marcadores RAPD (DNA Polimórfico Amplificado ao Acaso, que permitiram, com o auxílio de iniciadores aleatórios, a caracterização dos locos polimórficos identificados por uma matriz de ausência e presença de bandas. Utilizando essa matriz, a análise de agrupamento permitiu nítida classificação dos acessos em três grupos com diferenças genéticas entre eles. Um ensaio de controle químico, com plantas mantidas em vasos plásticos (5 L e pulverizadas com o herbicida glyphosate nas concentrações de 0,0, 0,6, 1,2, 1,8 e 2,4 kg ha-1, identificou, utilizando avaliações aos 7, 14 e 21 dias após aplicação, que as duas maiores doses promoveram melhor efeito herbicida. Foi verificado também que os acessos de Curitiba e Cambaratiba apresentaram menor suscetibilidade ao herbicida glyphosate. Não houve correspondência entre a estrutura de grupos dos acessos pela análise multivariada de agrupamento com a técnica RAPD e a suscetibilidade da alface-d'água ao glyphosate.Water lettuce (Pistia stratiotes is one the most important macrophytes, classified as weed and causing serious problems in watercourses in Brazil. The aim of this research was to evaluate the genetic variability of water lettuce and its relationship with this plant's susceptibility to glyphosate. 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.

E.A.S. Cícero

2007-09-01

27

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

International Nuclear Information System (INIS)

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 Cu2+ based on the fluorescence quenching. Highlights: ? Water soluble CdTe/CdS quantum dots capped with glyphosate were firstly synthesized. ? The fluorescence of the Glyp-functionalized QDs was quenched by copper ion. ? A new fluorescent sensor for copper ion was developed based on the prepared QDs. ? The sensor exhibited high sensitivity and good selectivity for copper ion. - Abstract: A novel fluorescent probe for Cu2+ 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 Cu2+ between 2.4 × 10?2 ?g mL?1 and 28 ?g mL?1, with a detection limit of 1.3 × 10?3 ?g mL?1 (3?). The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu2+. The fluorescent probe was successfully used for the determination of Cu2+ in environmental samples. Thetal samples. The mechanism of reaction was also discussed.

28

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)

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.

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

29

Glyphosate Accumulation and Detrimental Effects on Coffea Arabica : Chemical Analysis and Biological Effect Measurements  

DEFF Research Database (Denmark)

Coffee is one of the most popular beverages worldwide and a highly traded commodity. In order to maintain a high yield of the perennial crop, weed competition for resources needs to be reduced. For this purpose herbicides are commonly applied, with glyphosate being one of the most prominent herbicides in coffee fields. Glyphosate [N-(phosphonomethyl)glycine], the active ingredient in Roundup®, is characterized as systemic, non-selective, with a broad weed spectrum, inhibiting the enzyme 5-enolpyruvyl shikimate 3-phosphate synthase (EPSPS). The inhibition leads to an accumulation of shikimic acid. In coffee plantations glyphosate symptoms are commonly observed, probably caused by an unintentional spray drift. Root uptake represents an additional uptake route. Glyphosate can be applied several times per year thus a potential accumulation within the plant would lead to higher tissue concentrations than from single applications. The aim of this PhD thesis was to investigate the interaction of glyphosate with the coffee plant. An optimized coffee production, by minimizing the risk for a potential yield loss, is important due to the high commercial value of the crop. However, only limited data is available on the interaction of glyphosate with coffee trees and perennial crops in general; especially with respect to extended time periods after the exposure and multiple applications within the commercial life span of the individual plant. In order to determine glyphosate and aminomethylphosphonic acid (AMPA), the main glyphosate metabolite, in leaf material a method using liquid chromatography coupled to mass spectrometry (LC-MS) was developed. Variations of the method were tested using a full or simplified sample clean-up procedure with single quadrupole MS detection. Additionally the simplified sample treatment was further developed by the use of ultra performance liquid chromatography (UPLC) coupled to a triple quadrupole MS/MS system. All tested variations showed sufficient accuracy (recovery: 80-120%) and precision (? 20 relative standard deviation in percentage, RSD%). The full method and the MS/MS system provided a limit of quantification (LOQ) below 0.1 mg/kg; the commonly used maximum residue limit (MRL) for glyphosate in plant derived food products. Glyphosate was found in all samples analyzed from different coffee fields, regardless of management practices. AMPA was not detected above the LOQ in any greenhouse or field sample analyzed. Glyphosate levels seemed to increase in leaf material with multiple applications, indicating the risk for an accumulation in the coffee tree. In an experimental field trial glyphosate was, however, not detected after several applications. The biological response of young coffee plants to single glyphosate applications was evaluated using doseresponse curves (DRC) and shikimic acid levels. Furthermore the effect of multiple exposures on the viii severity of plant damage was investigated. The DRC revealed the presence of glyphosate symptoms to be the most sensitive response variable evaluated. Consequently, when symptoms are absent the risk for plant damage and yield loss is low. The field rate used in the greenhouse study, causing symptoms in 50% of the plants was realistic for field exposure scenarios. When symptoms are present, presumably caused by glyphosate, shikimic acid accumulation can be used for confirmation purposes. The best sampling time was 1 to 2 weeks after treatment, using only the youngest leaves of the plant. Shikimic acid levels were correlated with glyphosate levels 14 to 28 days after treatment (DAT). Earlier and later sampling did not show this correlation within the greenhouse study. A negative effect of glyphosate on the yield, correlated to plant leaf coverage was observed. The yield reduction was only observed for the first application carried out and not distinctively related to the number of applications or field rate. Most likely because of the plant age, possible other reasons are discussed. Biological response variables were not significantly increased by

Schrübbers, Lars Christoph

2015-01-01

30

Acute stress selectively reduces reward sensitivity  

Directory of Open Access Journals (Sweden)

Full Text Available Stress may promote the onset of psychopathology by disrupting reward processing. However, the extent to which stress impairs reward processing, rather than incentive processing more generally, is unclear. To evaluate the specificity of stress-induced reward processing disruption, 100 psychiatrically healthy females were administered a probabilistic stimulus selection task enabling comparison of sensitivity to reward-driven (Go and punishment-driven (NoGo learning under either ‘no stress’ or ‘stress’ (threat-of-shock conditions. Cortisol samples and self-report measures were collected. Contrary to hypotheses, the groups did not differ significantly in task performance or cortisol reactivity. However, further analyses focusing only on individuals under ‘stress’ who were high responders with regard to both cortisol reactivity and self-reported negative affect revealed reduced reward sensitivity relative to individuals tested in the ‘no stress’ condition; importantly, these deficits were reward-specific. Overall, findings provide preliminary evidence that stress-reactive individuals show diminished sensitivity to reward but not punishment under stress. While such results highlight the possibility that stress-induced anhedonia might be an important mechanism linking stress to affective disorders, future studies are necessary to confirm this conjecture.

LisaHBerghorst

2013-04-01

31

Efecto del glifosato sobre el crecimiento y acumulación de azúcares libres en dos biotipos de lolium perenne de distinta sensibilidad al herbicida Glyphosate effects on the growth and free sugar accumulation of two lolium perenn e biotypes with different herbicide sensitivity  

Directory of Open Access Journals (Sweden)

Full Text Available El movimiento sistémico del glifosato está determinado por el transporte de fotoasimilados. A su vez, la capacidad de un destino de consumir los asimilados está condicionada por su actividad metabólica. Pese a su importancia, la relación entre el glifosato y la síntesis de azúcares en hojas fuente ha sido poco abordada. El objetivo del presente trabajo fue evaluar los efectos del glifosato sobre el crecimiento y la acumulación de azúcares libres en dos biotipos de Lolium perenne de baja y alta sensibilidad al herbicida. Se trabajó con clones de ambos tipos de plantas, en macollaje, tratados con 1.440 g e.a. ha-1 de glifosato y sin tratamiento herbicida como controles. Se evaluó periódicamente el efecto del glifosato sobre el rebrote de hojas hasta las 50 horas post-aplicación y sobre los niveles de azúcares libres totales, reductores y no reductores en hojas a 1, 2, 3 y 5 días post-aplicación. A partir de las 25 horas post-aplicación, el glifosato provocó una disminución del crecimiento del 58% en el biotipo susceptible, con una acumulación de azúcares libres superior al 90% con relación al control, desde el primer día post-aplicación en adelante. La inhibición del crecimiento, inducida por el glifosato en plantas susceptibles, no depende de la limitación del traslado de fotoasimilados desde la parte aérea. Por tanto, la acumulación de azúcares libres en hojas podría explicarse por la caída en la tasa de crecimiento. En el biotipo de baja sensibilidad, en el que no se detectó inhibición del crecimiento, estos efectos fueron limitados.The systemic movement of glyphosate is determined by the transport of photoassimilates. In turn, the capacity of a destination to consume assimilates is conditioned by their metabolic activity. Despite its importance, the relationship between the glyphosate and the sugar synthesis from source leaves has been little studied. The aim of this work was to determine the effect of glyphosate on the growth and free sugar accumulation of two Lolium perenne biotypes of low and high glyphosate sensitivity. It was worked with clones of both types, in tillering, sprayed with 1,440 g a.e. ha-1 of glyphosate as treatments and without herbicide as controls. The glyphosate effects on the regrowth of leaves was studied until 50 hours post-application and on total free sugar, reducing free sugar and nonreducing free sugar from leaves to 1, 2, 3 and 5 days post-application were periodically evaluated. From 25 hours after glyphosate application, it caused on the susceptible biotype a growth decrease of 58% and an accumulation of free sugar above 90% compared to controls. In susceptible biotypes, growth inhibition does not depend on a reduced photoassimilate translocation from the overground part. Therefore, the free sugar accumulation in leaves could be explained by the fall in the rate of growth. These effects are limited in the low sensitivity biotype, where growth inhibition has not been detected.

M. Yanniccari

2012-03-01

32

Efecto del glifosato sobre el crecimiento y acumulación de azúcares libres en dos biotipos de lolium perenne de distinta sensibilidad al herbicida / Glyphosate effects on the growth and free sugar accumulation of two lolium perenn e biotypes with different herbicide sensitivity  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Spanish Abstract in spanish El movimiento sistémico del glifosato está determinado por el transporte de fotoasimilados. A su vez, la capacidad de un destino de consumir los asimilados está condicionada por su actividad metabólica. Pese a su importancia, la relación entre el glifosato y la síntesis de azúcares en hojas fuente h [...] a sido poco abordada. El objetivo del presente trabajo fue evaluar los efectos del glifosato sobre el crecimiento y la acumulación de azúcares libres en dos biotipos de Lolium perenne de baja y alta sensibilidad al herbicida. Se trabajó con clones de ambos tipos de plantas, en macollaje, tratados con 1.440 g e.a. ha-1 de glifosato y sin tratamiento herbicida como controles. Se evaluó periódicamente el efecto del glifosato sobre el rebrote de hojas hasta las 50 horas post-aplicación y sobre los niveles de azúcares libres totales, reductores y no reductores en hojas a 1, 2, 3 y 5 días post-aplicación. A partir de las 25 horas post-aplicación, el glifosato provocó una disminución del crecimiento del 58% en el biotipo susceptible, con una acumulación de azúcares libres superior al 90% con relación al control, desde el primer día post-aplicación en adelante. La inhibición del crecimiento, inducida por el glifosato en plantas susceptibles, no depende de la limitación del traslado de fotoasimilados desde la parte aérea. Por tanto, la acumulación de azúcares libres en hojas podría explicarse por la caída en la tasa de crecimiento. En el biotipo de baja sensibilidad, en el que no se detectó inhibición del crecimiento, estos efectos fueron limitados. Abstract in english The systemic movement of glyphosate is determined by the transport of photoassimilates. In turn, the capacity of a destination to consume assimilates is conditioned by their metabolic activity. Despite its importance, the relationship between the glyphosate and the sugar synthesis from source leaves [...] has been little studied. The aim of this work was to determine the effect of glyphosate on the growth and free sugar accumulation of two Lolium perenne biotypes of low and high glyphosate sensitivity. It was worked with clones of both types, in tillering, sprayed with 1,440 g a.e. ha-1 of glyphosate as treatments and without herbicide as controls. The glyphosate effects on the regrowth of leaves was studied until 50 hours post-application and on total free sugar, reducing free sugar and nonreducing free sugar from leaves to 1, 2, 3 and 5 days post-application were periodically evaluated. From 25 hours after glyphosate application, it caused on the susceptible biotype a growth decrease of 58% and an accumulation of free sugar above 90% compared to controls. In susceptible biotypes, growth inhibition does not depend on a reduced photoassimilate translocation from the overground part. Therefore, the free sugar accumulation in leaves could be explained by the fall in the rate of growth. These effects are limited in the low sensitivity biotype, where growth inhibition has not been detected.

M., Yanniccari; C., Istilart; D.O., Giménez; H., Acciaresi; A.M, Castro.

2012-03-01

33

Glyphosate persistence in seawater.  

Science.gov (United States)

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. PMID:24467857

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

2014-08-30

34

INFLUENCE OF DRIFT CONTROL ADJUVANTS ON APPLICATIONS OF GLYPHOSATE  

Science.gov (United States)

The volume of fine, highly driftable spray droplets (glyphosate herbicide (0.45 kg/ai in 94 L of water/ha and 276 kPa pressure) was 58 and 56% for glyphosate with no drift control adjuvant both with and without surfactant, respectively, and was variously reduced from 5 to 4...

35

Efeitos de diferentes formulações comerciais de glyphosate sobre estirpes de Bradyrhizobium Effects of different glyphosate commercial formulations on Bradyrhizobium strains  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi avaliar efeitos de formulações comerciais de glyphosate sobre estirpes de Bradyrhizobium, em condições de laboratório. As formulações foram aplicadas na concentração de 43,2 µg L-1 do equivalente ácido. As bactérias foram inoculadas em meio de cultura à base de manitol e extrato de levedura (YM. O efeito do herbicida no crescimento das estirpes de Bradyrhizobium foi avaliado mediante leitura da densidade ótica em espectrofotômetro. Avaliou-se o crescimento das estirpes de B. japonicum SEMIA 5079 e de B. elkanii SEMIA 5019 e SEMIA 587 sob efeito de nove formulações de glyphosate: Zapp Qi®, Roundup®, Roundup Multiação®, Roundup Transorb®, Roundup WG®, Trop®, Agrisato®, glyphosate técnico [padrão de N-(phosphonomethyl glycina] e controle sem adição de herbicida (testemunha para as estirpes. Foram utilizadas seis repetições. Confeccionaram-se curvas de crescimento para cada estirpe. Pelos resultados, pôde-se observar que todas as formulações de glyphosate causaram efeitos diferenciados sobre as estirpes de Bradyrhizobium SEMIA 5019, SEMIA 5079 e SEMIA 587. Constatou-se que a formulação Zapp Qi foi a menos tóxica às estirpes de Bradyrhizobium avaliadas. A maior toxicidade foi observada para Roundup Transorb, que provocou reduções no crescimento acima de 94% para todas as estirpes de Bradyrhizobium estudadas. Não se observou correlação entre o tipo de sal - isopropilamina, amônio ou potássico, presentes na formulação herbicida - e o grau de inibição no crescimento das estirpes. SEMIA 587 foi a estirpe menos tolerante à maioria das formulações testadas, porém SEMIA 5019 foi a mais sensível ao glyphosate padrão, sem adição de sais ou de outros aditivos.This work aimed to evaluate the effects of glyphosate commercial formulations on Bradyrhizobium strains under laboratory conditions. The formulations were applied in the concentration of 43.2 µg L-1 of the a.e. and the strains were inoculated in yeast extract manitol (YM. Herbicide effect on the growth of the Bradyrhizobium strains was assessed by optic density reading in a spectrophotometer. Twenty seven treatments arranged in a factorial design were evaluated and consisted of one strain of B. japonicum: SEMIA 5079; and two strains of B. elkanii: SEMIA 5019 and SEMIA 587, under the effect of nine glyphosate formulations: Zapp QI®, Roundup®, Roundup Multiação®, Roundup Transorb®, Roundup WG®, Trop®, Agrisato®, technical glyphosate [N-(phosphonomethyl glycine] and control without herbicide addition (as the strain control treatment, with six replications. A growth curve was established for each strain. It could be observed that the different glyphosate formulations Zapp Qi, Roundup, Roundup Multiação, Roundup transorb, Roundup WG, Trop and Agrisato caused differentiated effects on the strains of Bradyrhizobium SEMIA 5019, SEMIA 5079 and SEMIA 587. It was verified that the Zapp Qi formulation was the least toxic to the strains. The highest toxicity was observed for Roundup Transorb, which reduced growth over 94% for all the strains assessed. Correlation was not observed among the type of salt, isopropylamine, ammonium or potassic, present in the formulation herbicides, and the toxicity degree to the strains. The strain SEMIA 587 was the least tolerant to most formulations while SEMIA 5019 was the most sensitive to the control treatment N- (phosphonomethyl glycine, without salts or other additives.

J.B. Santos

2004-06-01

36

Nitrogen metabolism and flower symmetry of petunia corollas treated with glyphosate.  

Science.gov (United States)

A change of flower shape was observed in petunia corollas treated with 0.5 mM glyphosate. Glyphosate changed the flower symmetry from the actinomorphic type to the zygomorphic type. Corollas treated with glyphosate showed an increased free amino acid content. Free amino acid profiles in petunia corollas revealed that glyphosate had no significant effect on aromatic amino acid levels but increased the level of proline. Soluble protein content in glyphosate-treated corollas did not cause any significant changes. The contents of soluble phenolics, lignin, and IAA in the corollas were not significantly affected by the glyphosate treatment. In contrast, glyphosate reduced the nitrate content and the RNA content of petunia corollas by 45% and 63% of the control, respectively. However, the DNA content in glyphosate-treated corollas was similar to that of the control. Low concentrations of glyphosate did not show any phytotoxic effects on the whole plants and any remarkable changes on aromatic amino acid metabolism and protein synthesis. However, glyphosate reduced the RNA content of petunia corollas and changed the flower symmetry from the actinomorphic type to the zygomorphic type. The results of nonprotein nitrogen metabolism in glyphosate-treated petunia corollas suggested that glyphosate application at low concentration may influence the regulation of flower symmetry through the change of RNA biosynthesis. PMID:18274289

Shimada, Atsumi; Kimura, Yasuo

2007-01-01

37

Glyphosate and fungicide effects on Cercospora leaf spot in four glyphosate-resistant sugar beet (Beta vulgaris) varieties  

Science.gov (United States)

Glyphosate has been shown to reduce foliar diseases in soybean and wheat. In fact, currently there is a patent application for a synergistic combination of glyphosate and a fungicide for disease management. Cercospora leaf spot (Cercospora beticola) is one of the most significant foliar disease prob...

38

76 FR 19701 - Glyphosate (N-  

Science.gov (United States)

...EPA-HQ-OPP-2009-0988; FRL-8866-8] Glyphosate (N-(phosphonomethyl) glycine...established tolerance for residues of glyphosate in or on sweet corn, grain with corn...established tolerance for residues of glyphosate and N-acetyl-glyphosate in or...

2011-04-08

39

Glyphosate metabolism in plants  

Science.gov (United States)

Many soil microbes and plant species metabolically degrade the herbicide glyphosate. The primary degradation routes are by a glyphosate oxidoreductase (GOX) to form aminomethylphosphonic acid (AMPA) as the distinctive metabolite and by a C-P lyase that forms sarcosine as a main metabolite. AMPA app...

40

Reduced insulin sensitivity as a marker for acute mountain sickness?  

OpenAIRE

Spliethoff, Kerstin, Daniela Meier, Isabelle Aeberli, Max Gassmann, Wolfgang Langhans, Marco Maggiorini, Thomas A. Lutz, and Oliver Goetze. Reduced insulin sensitivity as a marker for acute mountain sickness? High Alt Med Biol 14:240-250, 2013-Reduced insulin sensitivity might increase the susceptibility to acute mountain sickness (AMS). The diabetogenic side effects of dexamethasone should therefore be considered for AMS treatment. To examine whether reduced insulin sensitivity is predictive...

Spliethoff, Kerstin; Meier, Daniela; Aeberli, Isabelle; Gassmann, Max; Langhans, Wolfgang; Maggiorini, Marco; Lutz, Thomas A.; Goetze, Oliver

2013-01-01

41

Acute stress selectively reduces reward sensitivity  

OpenAIRE

Stress may promote the onset of psychopathology by disrupting reward processing. However, the extent to which stress impairs reward processing, rather than incentive processing more generally, is unclear. To evaluate the specificity of stress-induced reward processing disruption, 100 psychiatrically healthy females were administered a probabilistic stimulus selection task (PSST) that enabled comparison of sensitivity to reward-driven (Go) and punishment-driven (NoGo) learning under either “...

LisaHBerghorst; DiegoAPizzagalli; RyanBogdan; MichaelJFrank

2013-01-01

42

Reduced taste sensitivity in congenital blindness  

DEFF Research Database (Denmark)

Sight is undoubtedly not only important for food identification and selection but also for the modulation of gustatory sensitivity. We can, therefore, assume that taste sensitivity and eating habits are affected by visual deprivation from birth. We measured taste detection and identification thresholds of the 5 basic tastants in 13 congenitally blind and 13 sighted control subjects. Participants also answered several eating habits questionnaires, including the Food Neophobia Scale, the Food Variety Seeking Tendency Scale, the Intuitive Eating Scale, and the Body Awareness Questionnaire. Our behavioral results showed that compared with the normal sighted, blind subjects have increased thresholds for taste detection and taste identification. This finding is at odds with the superior performance of congenitally blind subjects in several tactile, auditory and olfactory tasks. Our psychometric data further indicate that blind subjects more strongly rely on internal hunger and satiety cues, instead of external contextual or emotional cues, to decide when and what to eat. We suggest that the lower taste sensitivity observed in congenitally blind individuals is due to various blindness-related obstacles when shopping for food, cooking and eating out, all of which contribute to underexpose the gustatory system to a larger variety of taste stimuli.

Gagnon, Lea; Kupers, Ron

2013-01-01

43

Oxidative stress induced by a commercial glyphosate formulation in a tolerant strain of Chlorella kessleri.  

Science.gov (United States)

We studied the toxicity of a glyphosate formulation and provide evidence of metabolic alterations due to oxidative stress caused in a Chlorella kessleri tolerant strain by exposure to the herbicide. After 96 h of exposure to increasing concentrations of the herbicide (0-70 mg L(-1)) with alkylaryl polyglycol ether surfactant, growth was inhibited (EC50-96 h 55.62 mg L(-1)). Glyphosate increased protein and malondialdehyde content which was significantly higher than in the control at 50-70 mg L(-1). Superoxide dismutase and catalase activities and reduced glutathione levels increased in a concentration-dependant manner. Morphological studies showed increases in vacuolisation and in cell and sporangia sizes. The glyphosate formulation studied has a cytotoxic effect on C. kessleri through a mechanism that would involve the induction of oxidative stress. Upon glyphosate exposure, oxidative stress parameters such as SOD and CAT activities and MDA level could be more sensitive biomarkers than usually tested growth parameters in C. kessleri. PMID:21074853

Romero, Delfina M; Ríos de Molina, María C; Juárez, Angela B

2011-05-01

44

Glyphosate-Resistant Goosegrass from Mississippi  

Directory of Open Access Journals (Sweden)

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.

Vijay K. Nandula

2013-05-01

45

Effects of additives on glyphosate activity in purple nutsedge  

International Nuclear Information System (INIS)

Effects of additives on 14 C-glyphosate penetration into purple nutsedge leaves were examined in the laboratory and efficacy of glyphosate for purple nutsedge control was studied in the greenhouse and field. The addition of (NH4)2 SO4 at 1.0% (v/v) + diesel oil at 1,0% (v/v) + Tendal at 1.0% (v/v) increased 14C-glyphosate penetration into nutsedge leaves more than the addition of either one alone. (NH4)2SO4 at 1.0% + diesel oil at 1.0% + Tendal at 0.12 or 0.25% increased the phytotoxicity of glyphosate at 0.5 and 0.75 kg, a.e./ha on nutsedge plants in the greenhouse but not in the field. Additives did not enhance glyphosate activity by reducing the number of nutsedae tubers. (author)

46

Estádio de desenvolvimento e superfície foliar reduzem a eficiência de chlorimuron-ethyl e glyphosate em Conyza sumatrensis / Developmental stage and leaf surface reduce the efficiency of chlorimuron-ethyl and glyphosate in Conyza sumatrensis  

Scientific Electronic Library Online (English)

Full Text Available Nos Estados do Rio Grande do Sul e do Paraná, há frequentes relatos de falhas de controle de Conyza sumatrensis com chlorimuron-ethyl em lavouras de soja. Assim, os objetivos deste trabalho foram caracterizar morfologicamente as folhas de Conyza sumatrensis e avaliar o controle com herbicidas aplica [...] dos em biótipos dessa planta daninha em três estádios de desenvolvimento. Foram realizados dois estudos, com experimentos em casa de vegetação, em delineamento inteiramente casualizado com quatro repetições. No primeiro estudo, os biótipos de buva foram coletados e identificados; já no segundo estudo avaliou-se a resposta de biótipos aos herbicidas, doses e estádios de desenvolvimento. As doses de herbicidas foram: 0,0; 6,25; 12,5; 25; 50; 100; 200; e 400, representadas em porcentagem da dose de registro dos herbicidas chlorimuron-ethyl (20 g ha-1) e glyphosate (720 g e.a. ha-1), aplicadas de modo isolado ou associadas em três estádios de desenvolvimento dos quatro biótipos (2, 5, 17 e 20) de Conyza sumatrensis (altura de 0,5-1 cm e 3-4 folhas; altura 1-2 cm e 6-7 folhas; e altura de 10-12 cm e 12-14 folhas). As variáveis analisadas foram controle, fitomassa seca da parte aérea e as densidades tricomática e estomática da superfície foliar dos biótipos em diferentes estádios de desenvolvimento. Os resultados demonstram que os estádios de desenvolvimento alteram a eficácia dos herbicidas, e aplicações em estádios avançados de desenvolvimento diminuem a eficácia de controle. A exceção foi o biótipo 5 de Conyza sumatrensis, que demonstrou resistência ao glyphosate, independentemente do estádio de desenvolvimento no momento da aplicação do herbicida. Houve variação no número de tricomas entre os biótipos em todos os estádios de desenvolvimento, e o número de estômatos diminuiu com o desenvolvimento dos biótipos. Abstract in english In the states of Rio Grande do Sul and Paraná, there are frequent reports of failure to control Conyza sumatrensis with chlorimuron-ethyl in soybean crops. Thus, the objectives of this study were to characterize Conyza sumatrensis leaves morphologically and evaluate herbicide control in biotypes of [...] this weed at three stages. Two studies were conducted, with experiments in a greenhouse in a completely randomized design with four replications. In the first study, horseweed biotypes were collected and identified, and the second study evaluated the responses of herbicide rates and development stages. The herbicide rates were: 0.0, 6.25, 12.5, 25, 50, 100, 200 and 400, represented as a percentage of the dose registry of herbicides chlorimuron­ethyl (20 g ha-1) and glyphosate (720 g e.a. ha-1) applied in isolation or associated at three developmental stages of four Conyza sumatrensis (2, 5, 17 and 20) biotypes (height = 0.5-1 cm and 3-4 leaves, height = 1-2 cm and 6-7 leaves, height = 10-12 cm, 12-14 leaves). The variables analyzed were control, shoot dry weight and trichome and stomatal densities biotypes of the leaf surface at different stages of development. The results obtained demonstrate that the developmental stages affect the effectiveness of the herbicides, and applications at advanced stages of development decrease the effectiveness of control. The exception was biotype 5 of Conyza sumatrensis, which shows resistance to glyphosate, regardless of stage of development at the time of herbicide application. There was variation in the number of trichomes among biotypes at all stages of development, and the number of stomata decreased with the development of biotypes.

F.M., Santos; L., Vargas; P.J., Christoffoleti; D., Agostinetto; T.N., Martin; Q., Ruchel; J.A., Fernando.

2014-06-01

47

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

Science.gov (United States)

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. PMID:24615870

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

2014-05-01

48

Inhibition effect of glyphosate on the acute and subacute toxicity of cadmium to earthworm Eisenia fetida.  

Science.gov (United States)

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. PMID:25043609

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

49

Hormesis with glyphosate depends on coffee growth stage  

Scientific Electronic Library Online (English)

Full Text Available Os sistemas de manejo de plantas daninhas em quase todos os pomares de café do Brasil permitem que o herbicida pulverizado sofra deriva sobre a cultura. Com objetivo de avaliar se há algum efeito do glyphosate, herbicida mais comumente utilizado em pomares de café, sobre as plantas de café, uma ampl [...] a faixa de doses do herbicida foi aplicada diretamente sobre plantas de café em dois distintos estádios de crescimento da planta. Embora o crescimento de ambas as plantas novas e velhas tenha sido reduzido em doses mais altas de glyphosate, baixas doses não causaram efeitos sobre características de crescimento de plantas novas e estimularam o crescimento das mais velhas. Portanto, o efeito hormético do glyphosate é dependente do estádio de crescimento da planta de café no momento da aplicação do herbicida. Abstract in english 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 c [...] offee plants at two distinct plant growth stages. Although growth of both young and old plants was reduced at higher glyphosate doses, low doses caused no effects on growth characteristics of young plants and stimulated growth of older plants. Therefore, hormesis with glyphosate is dependent on coffee plant growth stage at the time of herbicide application.

LEONARDO B. DE, CARVALHO; PEDRO L.C.A., ALVES; STEPHEN O., DUKE.

2013-06-01

50

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)

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. PMID:22224711

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

51

Functional characterization of aroA from Rhizobium leguminosarum with significant glyphosate tolerance in transgenic Arabidopsis.  

Science.gov (United States)

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. PMID:24836188

Han, Jing; Tian, Yong-Sheng; Xu, Jing; Wang, Li-Juan; Wang, Bo; Peng, Ri-He; Yao, Quan-Hong

2014-09-01

52

Nontarget mechanims involved in glyphosate tolerance found in Canavalia ensiformis plants.  

Science.gov (United States)

A glyphosate-tolerant population of Canavalia ensiformis was collected in a cover crop in citrus orchards in Veracruz (Mexico), where glyphosate had been used for the first time. A susceptible Amaranthus hybridus L. population was collected from a nearby field that had never been treated with glyphosate. Dose-response experiments indicated a glyphosate tolerance ratio [ED(50)(C. ensiformis)/ED(50) (A. hybridus)] of 7.7. The hypothesis of a high level of glyphosate tolerance was provisionally corroborated on the basis of shikimate accumulation in both species. The susceptible population accumulated 6 times more shikimic acid in leaf tissue 96 h after glyphosate application than the tolerant leguminous crop. Two different physiological factors were involved in the glyphosate tolerance of this C. ensiformis population, which were confirmed by [(14)C]glyphosate, being a lack of penetration of glyphosate through the cuticle of the leguminous plants and an impaired herbicide translocation to the roots and the rest of shoots. This paper reports that two different nontarget site-based mechanisms, limited absorption and reduced translocation, contribute to the glyphosate tolerance found in C. ensiformis. PMID:19432449

Cruz-Hipolito, Hugo; Osuna, Maria D; Heredia, Antonio; Ruiz-Santaella, Juan Pedro; De Prado, Rafael

2009-06-10

53

Root-Zone Glyphosate Exposure Adversely Affects Two Ditch Species  

OpenAIRE

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 wi...

Saunders, Lyndsay E.; Koontz, Melissa B.; Reza Pezeshki

2013-01-01

54

78 FR 25396 - Glyphosate; Pesticide Tolerances  

Science.gov (United States)

...common mechanism of toxicity.'' EPA has not found glyphosate to share a common mechanism of toxicity with any other substances, and glyphosate does not appear to...findings: i. The toxicity database for glyphosate is...

2013-05-01

55

Effects of glyphosate-resistant crop cultivation on soil and water quality.  

Science.gov (United States)

Transgenic glyphosate-resistant crops (GRCs) have been commercialized and grown extensively in the Western Hemisphere and, to a lesser extent, elsewhere. GRCs have generally become dominant in those countries where they have been approved for growing. Potential effects of glyphosate on soil and water are minimal, compared the effects of the herbicides that are replaced when GRCs are adopted. Perhaps the most important indirect effect is that GRCs crops promote the adoption of reduced- or no-tillage agriculture, resulting in a significant reduction in soil erosion and water contamination. Glyphosate and its degradation product, aminomethylphosphonate (AMPA), residues are not usually detected in high levels in ground or surface water in areas where glyphosate is used extensively.  Furthermore, both glyphosate and AMPA are considered to be much more toxicologically and environmentally benign than most of the herbicides replaced by glyphosate. PMID:21912208

Cerdeira, Antonio L; Duke, Stephen O

2010-01-01

56

Sustained mild hypergravity reduces spontaneous cardiac baroreflex sensitivity.  

Science.gov (United States)

Head-to-foot gravitational force >1G (+Gz hypergravity) augments venous pooling in the lower body and reduces central blood volume during exposure, compared with 1Gz. Central hypovolemia has been reported to reduce spontaneous cardiac baroreflex sensitivity. However, no investigations have examined spontaneous cardiac baroreflex sensitivity during exposure to sustained mild +Gz hypergravity. We therefore hypothesized that mild +Gz hypergravity would reduce spontaneous cardiac baroreflex sensitivity, compared with 1Gz. To test this hypothesis, we examined spontaneous cardiac baroreflex sensitivity in 16 healthy men during exposure to mild +Gz hypergravity using a short-arm centrifuge. Beat-to-beat arterial blood pressure (tonometry) and R-R interval (electrocardiography) were obtained during 1Gz and 1.5Gz exposures. Spontaneous cardiac baroreflex sensitivity was assessed by sequence slope and transfer function gain. Stroke volume was calculated from the arterial pressure waveform using a three-element model. All indices of spontaneous cardiac baroreflex sensitivity decreased significantly (up slope: 18.6±2.3?12.7±1.6ms/mmHg, P<0.001; down slope: 19.0±2.5?13.2±1.3ms/mmHg, P=0.002; transfer function gain in low frequency: 14.4±2.2?10.1±1.1ms/mmHg, P=0.004; transfer function gain in high frequency: 22.2±7.5?12.4±3.5ms/mmHg, P<0.001). Stroke volume decreased significantly (88±5?80±6ml, P=0.025). Moreover, although systolic arterial pressure variability increased, R-R interval variability did not increase. These results suggest that even mild +Gz hypergravity reduces spontaneous cardiac baroreflex sensitivity, increasing the risk of cardiovascular disturbance during the exposure. PMID:25156804

Yanagida, Ryo; Ogawa, Yojiro; Ueda, Kaname; Aoki, Ken; Iwasaki, Ken-ichi

2014-10-01

57

Selection and characterization of glyphosate tolerance in birdsfoot trefoil (Lotus corniculatus)  

International Nuclear Information System (INIS)

If birdsfoot trefoil (Lotus corniculatus L.) was tolerant to glyphosate [N-(phosphonomethyl)glycine], Canada thistle [Cirsium arvense (L.) Scop.] and other dicot weeds could be selectively controlled in certified seed production fields. Glyphosate tolerance in birdsfoot trefoil was identified in plants from the cultivar Leo, plants regenerated from tolerant callus, and selfed progeny of plants regenerated from callus. Plants from the three sources were evaluated in field studies for tolerance to glyphosate at rates up to 1.6 kg ae/ha. Plants of Leo selected for tolerance exhibited a twofold range in the rate required to reduce shoot weight 50% (I50s from 0.6 to 1.2 kg/ha glyphosate). Plants regenerated from tolerant callus had tolerance up to 66% greater than plants regenerated from unselected callus. Transgressive segregation for glyphosate tolerance was observed in the selfed progeny of two regenerated plants that both had I50s of 0.7 kg/ha glyphosate. The selfed progeny ranged from highly tolerant (I50 of 1.5 kg/ha) to susceptible (I50 of 0.5 kg/ha). Spray retention, 14C-glyphosate absorption and translocation did not account for the differential tolerance of nine plants that were evaluated from the three sources. The specific activity of 5-enolpyruvylshikimate 3-phosphate (EPSP) synthase ranged from 1.3 to 3.5 nmol/min sm-bullet mg among the nine plants and was positively correlated with glyphosate tolerance. ely correlated with glyphosate tolerance. Leo birdsfoot trefoil was found to have significant variation in glyphosate tolerance which made it possible to initiate a recurrent selection program to select for glyphosate tolerance in birdsfoot trefoil. Two cycles of selection for glyphosate tolerance were practiced in three birdsfoot trefoil populations, Leo, Norcen, and MU-81

58

Sintomas da intoxicação inicial de Eucalyptus proporcionados por subdoses de glyphosate aplicadas no caule ou nas folhas / Initial symptoms of Eucalyptus intoxication by glyphosate rates applied on the stem or leaves  

Scientific Electronic Library Online (English)

Full Text Available Com o objetivo de avaliar os sintomas de intoxicação causados pela aplicação de glyphosate, foi montado um estudo composto por quatro ensaios com aplicações de glyphosate (360 g e.a. L-1) em eucalipto. Em todos os ensaios, mudas foram transplantadas em vasos de 5,0 L. Nos ensaios 1 e 2, foram aplica [...] dos volumes crescentes de solução de glyphosate no caule do eucalipto. No ensaio 1, a solução de 3% (v/v) foi aplicada nos volumes de 0, 1, 5, 10, 20, 40, 80 e 160 µL de calda por planta e, no segundo, a solução de glyphosate a 2% (v/v) foi aplicada nos volumes de 0, 1, 5, 15, 30, 60, 90, 120 e 150 µL de calda por planta. Nos ensaios 3 e 4, foram feitas aplicações de glyphosate sobre as plantas de eucalipto. No ensaio 3, as doses foram de 0, 7,2.10-7, 7,2.10-6, 7,2.10-5, 7,2.10-4, 7,2.10-3, 7,2.10-2, 7,2.10-1, 7,2, 72, 360 e 720 g e.a. de glyphosate ha-1 e, no ensaio 4, de 0, 9, 18, 36, 72, 144, 288, 432, 576, 720, 1.080, 1.440 e 2.160 g e.a. de glyphosate ha-1. Nos quatro ensaios foi utilizado o delineamento DIC, com três repetições. Nas plantas, foram avaliadas a altura, a área foliar e a matéria seca de caule e folhas. Os resultados obtidos foram submetidos a análises de regressão. Quando aplicadas no caule, doses de 40,78 e 51,41 µL de calda por planta de glyphosate a 3 e 2% (v/v), respectivamente, nos ensaios 1 e 2, foram suficientes para redução média de 50% das características estudadas. Nas aplicações sobre as folhas, houve maior sensibilidade das plantas mais desenvolvidas. Para redução média de 50% nas variáveis analisadas, foram necessárias doses de 277,4 e 143,3 g e.a. de glyphosate ha-1 nos ensaios 3 e 4, respectivamente. Abstract in english This work was carried out to evaluate intoxication symptoms caused by glyphosate application. It was constituted by four assays with glyphosate applications (360 g a.e. L-1) on eucalyptus. In all assays, seedlings were transplanted into 5.OL plastic pots. In assays 1 and 2, increasing herbicide volu [...] mes were applied on the stem. In the first one, a glyphosate solution of 3% (v/v) was applied at the volumes 0, 1, 5, 10, 20, 40, 80 and 160 µL solution per plant, and in the second, glyphosate solution of 2% (v/v) was applied at volumes 0, 1, 5, 15, 30, 60, 90, 120 and 150 µL solution per plant. In assays 3 and 4, glyphosate was sprayed on the plants. The rates in the third assay were: 0, 7.2 10-7, 7.2 10-6, 7.2 10-5, 7.2 10-4, 7.2 10-3, 7.2 10-2, 7.2 10-1, 7.2, 72, 360 and 720 g a.e. of glyphosate ha 1, and in the fourth assay, the rates were: 0, 9, 18, 36, 72, 144, 288, 432, 576, 720, 1.080, 1.440 and 2.160 g a.e. of glyphosate ha-1. All assays were arranged in a randomized design, with three replications. Height, leaf area, and dry mass of the leaves and stem were evaluated in the plants and the results were submitted to regression analysis. When applied on the stem, doses of 40.78 and 51.41 µL per plant of glyphosate solution, 3 and 2% (v/v), respectively, were sufficient to reduce eucalyptus development in 50%. When applied on the plants, more developed plants showed greater sensitivity.Rates of 277.4 and 143.3 g a.e. ha-1 reduced eucalyptus growth in 50%, in assays 3 and 4, respectively.

T.P, Salgado; P.L.C.A, Alves; M.A, Kuva; E.N, Takahashi; T.C.S, Dias; L.N, Lemes.

2011-12-01

59

Sintomas da intoxicação inicial de Eucalyptus proporcionados por subdoses de glyphosate aplicadas no caule ou nas folhas Initial symptoms of Eucalyptus intoxication by glyphosate rates applied on the stem or leaves  

Directory of Open Access Journals (Sweden)

Full Text Available Com o objetivo de avaliar os sintomas de intoxicação causados pela aplicação de glyphosate, foi montado um estudo composto por quatro ensaios com aplicações de glyphosate (360 g e.a. L-1 em eucalipto. Em todos os ensaios, mudas foram transplantadas em vasos de 5,0 L. Nos ensaios 1 e 2, foram aplicados volumes crescentes de solução de glyphosate no caule do eucalipto. No ensaio 1, a solução de 3% (v/v foi aplicada nos volumes de 0, 1, 5, 10, 20, 40, 80 e 160 µL de calda por planta e, no segundo, a solução de glyphosate a 2% (v/v foi aplicada nos volumes de 0, 1, 5, 15, 30, 60, 90, 120 e 150 µL de calda por planta. Nos ensaios 3 e 4, foram feitas aplicações de glyphosate sobre as plantas de eucalipto. No ensaio 3, as doses foram de 0, 7,2.10-7, 7,2.10-6, 7,2.10-5, 7,2.10-4, 7,2.10-3, 7,2.10-2, 7,2.10-1, 7,2, 72, 360 e 720 g e.a. de glyphosate ha-1 e, no ensaio 4, de 0, 9, 18, 36, 72, 144, 288, 432, 576, 720, 1.080, 1.440 e 2.160 g e.a. de glyphosate ha-1. Nos quatro ensaios foi utilizado o delineamento DIC, com três repetições. Nas plantas, foram avaliadas a altura, a área foliar e a matéria seca de caule e folhas. Os resultados obtidos foram submetidos a análises de regressão. Quando aplicadas no caule, doses de 40,78 e 51,41 µL de calda por planta de glyphosate a 3 e 2% (v/v, respectivamente, nos ensaios 1 e 2, foram suficientes para redução média de 50% das características estudadas. Nas aplicações sobre as folhas, houve maior sensibilidade das plantas mais desenvolvidas. Para redução média de 50% nas variáveis analisadas, foram necessárias doses de 277,4 e 143,3 g e.a. de glyphosate ha-1 nos ensaios 3 e 4, respectivamente.This work was carried out to evaluate intoxication symptoms caused by glyphosate application. It was constituted by four assays with glyphosate applications (360 g a.e. L-1 on eucalyptus. In all assays, seedlings were transplanted into 5.OL plastic pots. In assays 1 and 2, increasing herbicide volumes were applied on the stem. In the first one, a glyphosate solution of 3% (v/v was applied at the volumes 0, 1, 5, 10, 20, 40, 80 and 160 µL solution per plant, and in the second, glyphosate solution of 2% (v/v was applied at volumes 0, 1, 5, 15, 30, 60, 90, 120 and 150 µL solution per plant. In assays 3 and 4, glyphosate was sprayed on the plants. The rates in the third assay were: 0, 7.2 10-7, 7.2 10-6, 7.2 10-5, 7.2 10-4, 7.2 10-3, 7.2 10-2, 7.2 10-1, 7.2, 72, 360 and 720 g a.e. of glyphosate ha 1, and in the fourth assay, the rates were: 0, 9, 18, 36, 72, 144, 288, 432, 576, 720, 1.080, 1.440 and 2.160 g a.e. of glyphosate ha-1. All assays were arranged in a randomized design, with three replications. Height, leaf area, and dry mass of the leaves and stem were evaluated in the plants and the results were submitted to regression analysis. When applied on the stem, doses of 40.78 and 51.41 µL per plant of glyphosate solution, 3 and 2% (v/v, respectively, were sufficient to reduce eucalyptus development in 50%. When applied on the plants, more developed plants showed greater sensitivity.Rates of 277.4 and 143.3 g a.e. ha-1 reduced eucalyptus growth in 50%, in assays 3 and 4, respectively.

T.P Salgado

2011-12-01

60

GLYPHOSATE AND GLYPHOSATE-RESISTANT CROP INTERACTIONS WITH RHIZOSPHERE MICROORGANISMS  

Science.gov (United States)

Glyphosate and glyphosate-resistant crops represent a major advancement in effective weed management that is now widely used in many crop production systems. Studies conducted during 1997-2007 showed that Fusarium root colonization was consistently higher on Roundup Ready (RR) soybean treated with g...

61

A Preliminary Study of Soybean Genotype Responses to Glyphosate  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of four application rates of glyphosate (Roundup, 360 g a.i./l – 180; 360; 720 and 1440 g a.i./ha on the survival, dynamics of growth, and accumulation of fresh biomass in g per plant was studied on eight newly-developed Bulgarian lines, varieties and candidate varieties of soybean bred by different methods under greenhouse conditions. The objective of this study was to determine and compare the sensitivities of different soybean genotypes to glyphosate. The studied soybean genotypes showed different levelsof glyphosate sensitivity due to their genetic differences. Glyphosate rates of 180, 360, 720 and 1440 g a.i./ha, applied at the stage of three trifoliate leaves (V4 of soybean had effect on the survival of the studied genotypes and can be presented conditionally in the following order: H (40.6% < G (40.7% < D (51.3% < C (52.6% < F (58.9% < E (60.5% < B (62.0% < A (65.3%. The depression coefficients (B of the studied characteristics dependedmainly on soybean genotypes and the applied herbicide rates. The tested glyphosate rates showed a high (GI 26.5-51.6% to relatively low degree of toxicity (GI 16.0-18.7% in the studied soybean genotypes.

Plamen Marinov-Serafimov

2009-01-01

62

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 ...

63

DIFFERENTIAL RESPONSE OF CLONES OF EUCALYPT TO GLYPHOSATE1 / RESPOSTA DIFERENCIAL DE CLONES DE EUCALIPTO A GLYPHOSATE  

Scientific Electronic Library Online (English)

Full Text Available O controle de plantas daninhas é comumente feito com roçadas na entrelinha associada a aplicações dirigidas de glyphosate na linha de plantio de culturas arbóreas, acarretando risco de deriva ou aplicação acidental do herbicida, que pode afetar a cultura de interesse. O objetivo foi avaliar a respos [...] ta dos clones C219, GG100, I144 e I224 de eucalipto (Eucalyptus grandis x E. urophylla) a doses de glyphosate de 0, 18, 36, 72, 180, 360 e 720 g de equivalente ácido por hectare. Os clones apresentaram padrões de crescimento distintos no que se refere a altura da planta, número de folhas, massa seca do caule, taxa de crescimento relativo, taxa de assimilação líquida e taxa de crescimento foliar relativo. Os clones I144 e GG100 foram mais suscetíveis ao glyphosate, sendo as doses necessárias para reduzir a massa seca em 50% de 113,4 e 119,6 g ea ha-1, respectivamente. Os clones C219 e I224 foram menos suscetíveis ao glyphosate, sendo as doses necessárias para reduzir a massa seca em 50% de 237,5 e 313,5 gae ha-1, respectivamente. Clones de eucalipto respondem diferentemente à exposição ao glyphosate, e entre I224, C219, GG100 e I144 a suscetibilidade é aumentada. Abstract in english 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.

Leonardo Bianco de, Carvalho; Pedro Luis da Costa Aguiar, Alves; Flávia Regina da, Costa.

2015-02-01

64

Crop response to glyphosate trimesium sulphosate  

OpenAIRE

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...

Pavlovic, Danijela; Vrbnicanin, Sava; Reinhardt, Carl

2013-01-01

65

Uptake of Glyphosate by an Arthrobacter sp  

OpenAIRE

The uptake of glyphosate (N-[phosphonomethyl]glycine) by an Arthrobacter sp. which can utilize this herbicide as its sole source of phosphorus was investigated. Orthophosphate suppressed the expression of the uptake system for glyphosate and also competed with glyphosate for uptake. The Km for glyphosate uptake was 125 ?M, and the Ki for orthophosphate was 24 ?M. Organophosphonates as well as organophosphates inhibited glyphosate uptake, but only organophosphates and orthophosphate suppress...

Pipke, Ru?diger; Schulz, Arno; Amrhein, Nikolaus

1987-01-01

66

Epoxy resin monomers with reduced skin sensitizing potency.  

Science.gov (United States)

Epoxy resin monomers (ERMs), especially diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF), are extensively used as building blocks for thermosetting polymers. However, they are known to commonly cause skin allergy. This research describes a number of alternative ERMs, designed with the aim of reducing the skin sensitizing potency while maintaining the ability to form thermosetting polymers. The compounds were designed, synthesized, and assessed for sensitizing potency using the in vivo murine local lymph node assay (LLNA). All six epoxy resin monomers had decreased sensitizing potencies compared to those of DGEBA and DGEBF. With respect to the LLNA EC3 value, the best of the alternative monomers had a value approximately 2.5 times higher than those of DGEBA and DGEBF. The diepoxides were reacted with triethylenetetramine, and the polymers formed were tested for technical applicability using thermogravimetric analysis and differential scanning calorimetry. Four out of the six alternative ERMs gave polymers with a thermal stability comparable to that obtained with DGEBA and DGEBF. The use of improved epoxy resin monomers with less skin sensitizing effects is a direct way to tackle the problem of contact allergy to epoxy resin systems, particularly in occupational settings, resulting in a reduction in the incidence of allergic contact dermatitis. PMID:24830866

O'Boyle, Niamh M; Niklasson, Ida B; Tehrani-Bagha, Ali R; Delaine, Tamara; Holmberg, Krister; Luthman, Kristina; Karlberg, Ann-Therese

2014-06-16

67

An efficient method of reducing glass dispersion tolerance sensitivity  

Science.gov (United States)

Constraining the Seidel aberrations of optical surfaces is a common technique for relaxing tolerance sensitivities in the optimization process. We offer an observation that a lens's Abbe number tolerance is directly related to the magnitude by which its longitudinal and transverse color are permitted to vary in production. Based on this observation, we propose a computationally efficient and easy-to-use merit function constraint for relaxing dispersion tolerance sensitivity. Using the relationship between an element's chromatic aberration and dispersion sensitivity, we derive a fundamental limit for lens scale and power that is capable of achieving high production yield for a given performance specification, which provides insight on the point at which lens splitting or melt fitting becomes necessary. The theory is validated by comparing its predictions to a formal tolerance analysis of a Cooke Triplet, and then applied to the design of a 1.5x visible linescan lens to illustrate optimization for reduced dispersion sensitivity. A selection of lenses in high volume production is then used to corroborate the proposed method of dispersion tolerance allocation.

Sparrold, Scott W.; Shepard, R. Hamilton

2014-12-01

68

Isoflavone, Glyphosate and Aminomethylphosphonic Acid Levels in Seeds of Glyphosate-treated, Glyphosate-resistant Soybean  

Science.gov (United States)

The estrogenic isoflavones of soybeans and their glycosides are products of the shikimate pathway, the target pathway of glyphosate. We tested the hypothesis that non-phytotoxic levels of glyphosate and other herbicides known to affect phenolic compound biosynthesis might influence levels of these ...

69

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)

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%.

Joadil Gonçalves de Abreu

2006-10-01

70

Path-sensitive analysis for reducing rollback overheads  

Energy Technology Data Exchange (ETDEWEB)

A mechanism is provided for path-sensitive analysis for reducing rollback overheads. The mechanism receives, in a compiler, program code to be compiled to form compiled code. The mechanism divides the code into basic blocks. The mechanism then determines a restore register set for each of the one or more basic blocks to form one or more restore register sets. The mechanism then stores the one or more register sets such that responsive to a rollback during execution of the compiled code. A rollback routine identifies a restore register set from the one or more restore register sets and restores registers identified in the identified restore register set.

O' Brien, John K.P.; Wang, Kai-Ting Amy; Yamashita, Mark; Zhuang, Xiaotong

2014-07-22

71

Effects of glyphosate and its formulation, roundup, on reproduction in zebrafish (Danio rerio).  

Science.gov (United States)

Roundup and its active ingredient glyphosate are among the most widely used herbicides worldwide and may contaminate surface waters. Research suggests both Roundup and glyphosate induce oxidative stress in fish and may also cause reproductive toxicity in mammalian systems. We aimed to investigate the reproductive effects of Roundup and glyphosate in fish and the potential associated mechanisms of toxicity. To do this, we conducted a 21-day exposure of breeding zebrafish (Danio rerio) to 0.01, 0.5, and 10 mg/L (glyphosate acid equivalent) Roundup and 10 mg/L glyphosate. 10 mg/L glyphosate reduced egg production but not fertilization rate in breeding colonies. Both 10 mg/L Roundup and glyphosate increased early stage embryo mortalities and premature hatching. However, exposure during embryogenesis alone did not increase embryo mortality, suggesting that this effect was caused primarily by exposure during gametogenesis. Transcript profiling of the gonads revealed 10 mg/L Roundup and glyphosate induced changes in the expression of cyp19a1 and esr1 in the ovary and hsd3b2, cat, and sod1 in the testis. Our results demonstrate that these chemicals cause reproductive toxicity in zebrafish, although only at high concentrations unlikely to occur in the environment, and likely mechanisms of toxicity include disruption of the steroidogenic biosynthesis pathway and oxidative stress. PMID:24364672

Uren Webster, Tamsyn M; Laing, Lauren V; Florance, Hannah; Santos, Eduarda M

2014-01-21

72

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 pulverizaçã [...] o. 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. Abstract in english 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 curv [...] es (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+SA to glyphosate spray solution increased the control obtained at the lowest glyphosate rate (360 g ha-1), leveling it to the highest rate application (720 g ha-1) without adjuvants. These results show the complementary action of U and AMS to increase glyphosate efficacy to control D. insularis.

S.J.P., Carvalho; A.C.R., Dias; G.M., Shiomi; P.J., Christoffoleti.

73

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  

Directory of Open Access Journals (Sweden)

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+SA to glyphosate spray solution increased the control obtained at the lowest glyphosate rate (360 g ha-1, leveling it to the highest rate application (720 g ha-1 without adjuvants. These results show the complementary action of U and AMS to increase glyphosate efficacy to control D. insularis.

S.J.P. Carvalho

2010-01-01

74

Monitoring glyphosate residues in transgenic glyphosate-resistant soybean.  

Science.gov (United States)

The availability of Roundup Ready (RR) varieties of soybean has increased the use of glyphosate for weed control in Argentina. Glyphosate [(N-phosphonomethyl)glycine] is employed for the eradication of previous crop vegetation and for weed control during the soybean growing cycle. Its action is effective, and low environmental impact has been reported so far. No residues have been observed in soil or water, either of glyphosate or its metabolite, AMPA (aminomethylphosphonic acid). The objective of this work was to monitor glyphosate and AMPA residues in soybean plants and grains in field crops in Santa Fe Province, Argentina. Five sites were monitored in 1997, 1998 and 1999. Individual soybean plants were sampled from emergence to harvest, dried and ground. Analysis consisted in residue extraction with organic solvents and buffers, agitation, centrifugation, clean-up and HPLC with UV detection. In soybean leaves and stems, glyphosate residues ranged from 1.9 to 4.4 mg kg(-1) and from 0.1 to 1.8 mg kg(-1) in grains. Higher concentrations were detected when glyphosate was sprayed several times during the crop cycle, and when treatments approached the flowering stage. AMPA residues were also detected in leaves and in grains, indicating metabolism of the herbicide. PMID:14971683

Arregui, María C; Lenardón, Argelia; Sanchez, Daniel; Maitre, María I; Scotta, Roberto; Enrique, Susana

2004-02-01

75

Herança da resistência de azevém (Lolium multiflorum ao glyphosate Inheritance of azevém (Lolium multiflorum resistance to glyphosate  

Directory of Open Access Journals (Sweden)

Full Text Available O glyphosate é o principal produto usado para manejo não-seletivo das plantas daninhas. Já foram identificados biótipos de azevém resistentes a esse herbicida no Rio Grande do Sul, os quais estão se tornando predominantes rapidamente. Objetivou-se neste trabalho identificar o tipo de herança, o número de genes que conferem resistência e o grau de resistência dos biótipos homozigotos e heterozigotos resistentes em azevém. Foram realizados cruzamentos recíprocos entre genitores suscetíveis e resistentes para obtenção de sementes F1 e, em seguida, efetuaram-se os retrocruzamentos resistente e sensível. Plantas F1 foram cruzadas, para obtenção da geração F2. Sobre as plantas F1, F2, RCr e RCs e genitores foi aplicado o glyphosate na dose de 720 g ha-1, para avaliar a segregação. A fim de avaliar o grau de resistência, as plantas F1 e os genitores resistente e sensível foram tratados com doses crescentes de glyphosate (0, 360, 720, 1.440 e 2.880 g ha-1. As plantas F1 evidenciaram resposta intermediária ao biótipo resistente e sensível, demonstrando que a interação alélica é do tipo dominância incompleta. As plantas F2 mostraram tendência para segregação 3:1, indicando que a característica resistência ao glyphosate é controlada por um gene semidominante.Glyphosate is a non-selective herbicide used to control weeds. Azevem plants, which are tolerant to glyphosate, have been identified in Rio Grande do Sul, where they are rapidly becoming predominant. The objective of this work was to identify inheritance type, number of genes conferring resistance, and the degree of resistance in azevem plants. Reciprocal crossings between sensitive and resistant plants have been carried out to obtain F1 seeds which were crossed among themselves to obtain F2 plants .Herbicide containing 720 g ha-1 was applied on the F1, F2, RCr, Rc and parent plants to estimate segregation. To evaluate the degree of resistance of the F1 plants, resistant and sensitive parents were sprayed with increasing rates of glyphosate (0, 360, 720, 1.440 and 2.880 g ha-1. F1 plants showed intermediate response to the resistant and sensitive biotypes, indicating that allelic interaction is of the incomplete dominance type. F2 plants showed a tendency for segregation 3:1, indicating that resistance to glyphosate is controlled by a semi-dominant gene.

L. Vargas

2007-09-01

76

Herança da resistência de azevém (Lolium multiflorum) ao glyphosate / Inheritance of azevém (Lolium multiflorum) resistance to glyphosate  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O glyphosate é o principal produto usado para manejo não-seletivo das plantas daninhas. Já foram identificados biótipos de azevém resistentes a esse herbicida no Rio Grande do Sul, os quais estão se tornando predominantes rapidamente. Objetivou-se neste trabalho identificar o tipo de herança, o núme [...] ro de genes que conferem resistência e o grau de resistência dos biótipos homozigotos e heterozigotos resistentes em azevém. Foram realizados cruzamentos recíprocos entre genitores suscetíveis e resistentes para obtenção de sementes F1 e, em seguida, efetuaram-se os retrocruzamentos resistente e sensível. Plantas F1 foram cruzadas, para obtenção da geração F2. Sobre as plantas F1, F2, RCr e RCs e genitores foi aplicado o glyphosate na dose de 720 g ha-1, para avaliar a segregação. A fim de avaliar o grau de resistência, as plantas F1 e os genitores resistente e sensível foram tratados com doses crescentes de glyphosate (0, 360, 720, 1.440 e 2.880 g ha-1). As plantas F1 evidenciaram resposta intermediária ao biótipo resistente e sensível, demonstrando que a interação alélica é do tipo dominância incompleta. As plantas F2 mostraram tendência para segregação 3:1, indicando que a característica resistência ao glyphosate é controlada por um gene semidominante. Abstract in english Glyphosate is a non-selective herbicide used to control weeds. Azevem plants, which are tolerant to glyphosate, have been identified in Rio Grande do Sul, where they are rapidly becoming predominant. The objective of this work was to identify inheritance type, number of genes conferring resistance, [...] and the degree of resistance in azevem plants. Reciprocal crossings between sensitive and resistant plants have been carried out to obtain F1 seeds which were crossed among themselves to obtain F2 plants .Herbicide containing 720 g ha-1 was applied on the F1, F2, RCr, Rc and parent plants to estimate segregation. To evaluate the degree of resistance of the F1 plants, resistant and sensitive parents were sprayed with increasing rates of glyphosate (0, 360, 720, 1.440 and 2.880 g ha-1). F1 plants showed intermediate response to the resistant and sensitive biotypes, indicating that allelic interaction is of the incomplete dominance type. F2 plants showed a tendency for segregation 3:1, indicating that resistance to glyphosate is controlled by a semi-dominant gene.

L., Vargas; R.M.A., Moraes; C.M., Berto.

2007-09-01

77

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

Science.gov (United States)

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 accumula...

78

Glyphosate resistance: state of knowledge  

OpenAIRE

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 enzym...

Sammons, Robert Douglas; Gaines, Todd A.

2014-01-01

79

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)

Full Text Available Foram avaliados os efeitos da deriva de formulações comerciais de glyphosate sobre a superfície foliar e o crescimento de clones de eucalipto. Mudas de seis clones foram submetidas a 129,6 g ha-1 de glyphosate das formulações comerciais Scout®, Roundup NA®, Roundup transorb® e Zapp QI®. Entre os clones não foram identificadas diferenças quanto à tolerância ao glyphosate. Plantas expostas à deriva simulada de Roundup transorb® e Zapp QI® apresentaram, respectivamente, a maior e menor porcentagem de intoxicação. Observou-se menor massa seca em plantas expostas ao glyphosate, independentemente da formulação, e menor altura naquelas expostas ao Scout® e ao Roundup transorb®. As características quantitativas da superfície foliar não foram afetadas pelo glyphosate. As alterações micromorfológicas ocorreram na ausência de danos visíveis e foram observadas em ambas as faces da epiderme, em todos os clones avaliados. Danos como erosão e aspecto amorfo das ceras epicuticulares e infestação por hifas fúngicas ocorreram, independentemente da formulação utilizada. A avaliação anatômica da superfície foliar foi relevante para descrição e interpretação dos danos causados pelo glyphosate. Os dados de crescimento e de intoxicação indicam o Zapp QI® como a formulação de menor risco para a cultura do eucalipto quanto aos efeitos indesejáveis da deriva.The effects of commercial glyphosate drift on the leaf surface and growth of eucalypt clones were evaluated. Seedlings of six clones were submitted to 129.6 g ha-1 sub-rate of commercial glyphosate formulations Scout®, Roundup NA®, Roundup transorb® and Zapp QI®. No differences in tolerance to glyphosate were observed among the clones. Plants exposed to simulated drift of Roundup transorb® and Zapp QI® presented the highest and lowest intoxication percentages, respectively. Plants exposed to glyphosate reduced dry biomass, regardless of the formulation, and also 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.

L.D. Tuffi Santos

2009-01-01

80

Photosynthetic activity of coffee after application of glyphosate subdoses / Atividade fotossintética do cafeeiro após aplicação de subdoses de glyphosate  

Scientific Electronic Library Online (English)

Full Text Available Para o controle de plantas daninhas em lavouras cafeeiras, os produtores utilizam herbicidas não-seletivos, como o glyphosate, empregado em aplicações dirigidas. Apesar de todos os cuidados com a aplicação, são constatados casos de intoxicação em plantas, sendo de fundamental importância o conhecime [...] nto dos efeitos sobre os processos fotossintéticos. Objetivou-se com este trabalho avaliar as características associadas à atividade fotossintética entre cultivares de cafeeiro submetidos a doses de glyphosate. O experimento foi conduzido em casa de vegetação utilizando-se três cultivares de cafeeiro (Coffea arabica): Acaiá (MG-6851), Catucaí Amarelo (2 SL) e Topázio (MG-1190) e, três subdoses do glyphosate (0,0; 115,2 e 460,8 g ha-1), em esquema fatorial 3 x 3. Em função da aplicação do herbicida observou-se redução de carbono interno, razão carbono interno e do ambiente, consumo de carbono e taxa fotossintética, aos 15 DAA na quarta folha. Na mesma folha aos 45 DAA, constatou-se menor consumo de carbono pelos cultivares. Na última folha apesar de inferiores concentrações de carbono, não obteve-se diferença no consumo e taxa fotossintética. O glyphosate resulta em danos metabólicos com efeitos transitórios sobre a atividade fotossintética, sendo o cultivar Acaiá o mais tolerante. Este efeito transitório pode resultar em danos prolongados e irreversíveis no crescimento da cultura. Abstract in english Farmers use non-selective herbicides, such as glyphosate, in directed applications to control weeds in coffee crops. Despite the precautions used during the application of herbicides, there are usually reports of poisoning in plantation areas. Moreover, it is fundamental to understand the effects of [...] glyphosate on photosynthetic processes. The present study aimed to evaluate the characteristics associated with the photosynthetic activity in coffee cultivars subjected to doses of glyphosate. The experiment was conducted in a greenhouse using three varieties of coffee (Coffea arabica), including Acaiá (MG-6851), Catucaí Amarelo (2 SL) and Topázio (MG-1190), and three subdoses of glyphosate (0.0, 115.2 and 460.8 g ha-1) in a 3 x 3 factorial scheme. Herbicide application led to reduced internal carbon, ratio between internal and environmental carbon, carbon consumption and photosynthetic rate at 15 days after application (DAA) in the fourth leaf. In the same leaf at 45 DAA, the carbon consumption of the cultivars was even less. Despite low carbon concentrations, no difference in consumption and photosynthetic rate was observed in the last leaf. Glyphosate caused metabolic damage with transitory effects on the photosynthetic rate; the Acaiá cultivar was the most tolerant. These transitory effects may result in irreversible and prolonged damage to crop growth.

Felipe Paolinelli de, Carvalho; André Cabral, França; Vinícius Teixeira, Lemos; Evander Alves, Ferreira; José Barbosa dos, Santos; Antonio Alberto da, Silva.

2013-03-01

81

Resistência de azevém (Lolium multiflorum) ao herbicida glyphosate / Resistance of italian ryegrass (Lolium multiflorum) to glyphosate  

Scientific Electronic Library Online (English)

Full Text Available O azevém é uma gramínea de ciclo anual, constituindo-se com freqüência em planta infestante em lavouras de trigo do Rio Grande do Sul. Em experimentos realizados em casa de vegetação e no campo, foi avaliada a suscetibilidade de dois biótipos de azevém ao herbicida glyphosate, bem como a eficiência [...] de herbicidas de ação total na dessecação de Lolium multiflorum para a semeadura direta de trigo. O delineamento experimental foi completamente casualizado em casa de vegetação e de blocos ao acaso em campo, com três e quatro repetições, respectivamente. Foram avaliados herbicidas com mecanismos de ação distintos em diferentes doses: glyphosate, glufosinate, clethodim, haloxyfop-r e diclofop, paraquat e paraquat + diuron. Os resultados, em casa de vegetação, evidenciam que o biótipo sensível é totalmente controlado com glyphosate na dose de 360 g e.a. ha-1 e que doses de até 1.440 g e.a. ha-1 não afetam significativamente o acúmulo de matéria seca do biótipo resistente e produzem toxicidade inferior a 15% sobre este. Já as doses entre 1.440 e 5.760 g e.a. ha-1 de glyphosate reduzem significativamente a produção de matéria seca e resultam em toxicidade inferior a 45%. Em campo, os melhores controles de azevém foram propiciados pelos tratamentos clethodim (79,2 g ha-1) e diuron + paraquat (300 + 600 g ha-1), que não diferiram entre si. Assim, evidencia-se que a população de Lolium multiflorum avaliada neste trabalho é constituída predominantemente de um biótipo resistente aos herbicidas inibidores da enzima EPSPs. Abstract in english Italian ryegrass (Lolium multiflorum) is cultivated as forage and/or cover crop in no-till system. However, it is also a serious weed in wheat and other winter cereals in Southern Brazil. Experiments were conducted at greenhouse and field conditions to evaluate the susceptibility of two ryegrass bio [...] type to glyphosate as well as the efficacy of other herbicides on the post-emergence control of the species for sowing wheat under no-till system. The experimental design was a completely randomized design for the greenhouse experiment and a completely randomized block design for the field experiment. Herbicides with different mechanisms of action were evaluated on the weed control: glyphosate, glufosinate, clethodim, haloxyfop-r and diclofop, paraquat and paraquat+diuron. The results obtained under greenhouse conditions indicated the glyphosate susceptible biotype was controlled by the rate of 360 g e.a. ha-1. The resistant ryegrass biotype had no reduction in dry matter production and less than 15 % phytotoxicity caused by glyphosate up to 1,440 g e.a. ha-1. However, glyphosate rates between 1440 and 5,760 g e.a. ha-1 reduced dry matter accumulation and resulted in toxicities under45%. Under field conditions, the best Lolium multiflorum control was given by clethodim 79.2 g ha-1 and diuron + paraquat at 300+600 g ha¹, respectively. The results obtained in these studies indicated that the population was composed predominantly by a biotype resistant to EPSPs inhibitor herbicides.

E.S., Roman; L., Vargas; M.A., Rizzardi; R.W., Mattei.

2004-06-01

82

Resistência de azevém (Lolium multiflorum ao herbicida glyphosate Resistance of italian ryegrass (Lolium multiflorum to glyphosate  

Directory of Open Access Journals (Sweden)

Full Text Available O azevém é uma gramínea de ciclo anual, constituindo-se com freqüência em planta infestante em lavouras de trigo do Rio Grande do Sul. Em experimentos realizados em casa de vegetação e no campo, foi avaliada a suscetibilidade de dois biótipos de azevém ao herbicida glyphosate, bem como a eficiência de herbicidas de ação total na dessecação de Lolium multiflorum para a semeadura direta de trigo. O delineamento experimental foi completamente casualizado em casa de vegetação e de blocos ao acaso em campo, com três e quatro repetições, respectivamente. Foram avaliados herbicidas com mecanismos de ação distintos em diferentes doses: glyphosate, glufosinate, clethodim, haloxyfop-r e diclofop, paraquat e paraquat + diuron. Os resultados, em casa de vegetação, evidenciam que o biótipo sensível é totalmente controlado com glyphosate na dose de 360 g e.a. ha-1 e que doses de até 1.440 g e.a. ha-1 não afetam significativamente o acúmulo de matéria seca do biótipo resistente e produzem toxicidade inferior a 15% sobre este. Já as doses entre 1.440 e 5.760 g e.a. ha-1 de glyphosate reduzem significativamente a produção de matéria seca e resultam em toxicidade inferior a 45%. Em campo, os melhores controles de azevém foram propiciados pelos tratamentos clethodim (79,2 g ha-1 e diuron + paraquat (300 + 600 g ha-1, que não diferiram entre si. Assim, evidencia-se que a população de Lolium multiflorum avaliada neste trabalho é constituída predominantemente de um biótipo resistente aos herbicidas inibidores da enzima EPSPs.Italian ryegrass (Lolium multiflorum is cultivated as forage and/or cover crop in no-till system. However, it is also a serious weed in wheat and other winter cereals in Southern Brazil. Experiments were conducted at greenhouse and field conditions to evaluate the susceptibility of two ryegrass biotype to glyphosate as well as the efficacy of other herbicides on the post-emergence control of the species for sowing wheat under no-till system. The experimental design was a completely randomized design for the greenhouse experiment and a completely randomized block design for the field experiment. Herbicides with different mechanisms of action were evaluated on the weed control: glyphosate, glufosinate, clethodim, haloxyfop-r and diclofop, paraquat and paraquat+diuron. The results obtained under greenhouse conditions indicated the glyphosate susceptible biotype was controlled by the rate of 360 g e.a. ha-1. The resistant ryegrass biotype had no reduction in dry matter production and less than 15 % phytotoxicity caused by glyphosate up to 1,440 g e.a. ha-1. However, glyphosate rates between 1440 and 5,760 g e.a. ha-1 reduced dry matter accumulation and resulted in toxicities under45%. Under field conditions, the best Lolium multiflorum control was given by clethodim 79.2 g ha-1 and diuron + paraquat at 300+600 g ha¹, respectively. The results obtained in these studies indicated that the population was composed predominantly by a biotype resistant to EPSPs inhibitor herbicides.

E.S. Roman

2004-06-01

83

78 FR 60707 - Glyphosate; Pesticide Tolerances  

Science.gov (United States)

...glyphosate to the genetically modified ``Optimum GLY...residue in or on a food) only if EPA...Health Organization food standards program...international food safety standards-setting...glyphosate to genetically modified ``Optimum...

2013-10-02

84

75 FR 24969 - Glyphosate From China  

Science.gov (United States)

...COMMISSION [Investigation No. 731-TA-1178 (Preliminary)] Glyphosate From China AGENCY: United States International Trade Commission...gives notice that its antidumping investigation concerning glyphosate from China (investigation No. 731-TA-1178...

2010-05-06

85

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...

86

75 FR 17768 - Glyphosate From China  

Science.gov (United States)

...COMMISSION [Investigation No. 731-TA-1178 (Preliminary)] Glyphosate From China AGENCY: United States International Trade Commission...is materially retarded, by reason of imports from China of glyphosate, provided for in subheadings 2931.00.90 and...

2010-04-07

87

Glyphosate inhibits rust diseases in glyphosate-resistant wheat and soybean  

OpenAIRE

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. ...

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

88

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

Science.gov (United States)

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. PMID:17365326

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

2007-02-01

89

Atrazine and glyphosate dynamics in a lotic ecosystem: the common snapping turtle as a sentinel species.  

Science.gov (United States)

Atrazine and glyphosate are two of the most common pesticides used in the US Midwest that impact water quality via runoff, and the common snapping turtle (Chelydra serpentina) is an excellent indicator species to monitor these pesticides especially in lotic systems. The goals of this study were to (1) quantify atrazine, the atrazine metabolite diaminochlorotriazine (DACT), and glyphosate burdens in common snapping turtle tissue from individuals collected within the Embarras River in Illinois; (2) quantify atrazine, DACT, and glyphosate loads in water from the aquatic habitats in which common snapping turtles reside; and (3) investigate tissue loads based on turtle morphology and habitat choice. Concentrations of atrazine, DACT, and glyphosate in tissue did not show any relationship with lake habitat, carapace length, width, or mass. Both atrazine and glyphosate tissue samples varied as a function of site (river vs. lake), but DACT did not. Atrazine and glyphosate concentrations in water samples showed a linear effect on distance from the reservoir spillway and a deviation from linearity. Water column concentrations of all three contaminants varied across capture sites, but atrazine water concentration did not influence DACT water concentration nor did it exhibit a site interaction. Water atrazine and glyphosate concentrations were greater than tissue concentrations, whereas DACT water and tissue concentrations did not differ. This study showed that turtles are useful in long-term pesticide monitoring, and because DACT as a metabolite is less sensitive to variation, it should be considered as a preferred biomarker for pesticide runoff. PMID:25678354

Douros, Derrick L; Gaines, Karen F; Novak, James M

2015-03-01

90

76 FR 27268 - Glyphosate; Pesticide Tolerance  

Science.gov (United States)

...EPA-HQ-OPP-2010-0938; FRL-8872-6] Glyphosate; Pesticide Tolerance AGENCY: Environmental...established tolerance for residues of glyphosate in or on corn, field, forage. Monsanto...tolerance for residues of the herbicide glyphosate, N-(phosphonomethyl)...

2011-05-11

91

Qualidade fisiológica de sementes de soja colhidas em duas épocas após dessecação com glyphosate / Physiological quality of soybean seeds harvested at two periods after glyphosate desiccation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A dessecação de plantas de soja em pré-colheita com glyphosate vem se tornando prática rotineira entre os produtores, apesar de não ser recomendada, pois pode comprometer a qualidade fisiológica das sementes. Objetivou-se avaliar os efeitos da dessecação das plantas em pré-colheita com glyphosate na [...] qualidade fisiológica de sementes de soja colhidas em duas épocas após a aplicação. O delineamento experimental foi em blocos ao acaso, com quatro repetições, em esquema de parcelas subdivididas. As parcelas principais consistiram da dessecação ou não das plantas de soja com glyphosate em pré-colheita, no estádio R7, e as subparcelas da colheita das sementes 7 e 14 dias após a aplicação. As sementes foram avaliadas quanto ao teor de água, dano mecânico, viabilidade, massa de 100 sementes e teor de proteína. A qualidade fisiológica foi avaliada por meio dos testes de germinação, envelhecimento acelerado, condutividade elétrica, comprimento de plântulas e massa da matéria seca das plântulas. A dessecação das plantas de soja em pré-colheita com glyphosate ocasiona redução da germinação das sementes e do desenvolvimento inicial das plântulas. O atraso na colheita reduz a germinação das sementes oriundas de plantas de soja dessecadas com glyphosate em pré-colheita, mas minimiza os efeitos fitotóxicos no desenvolvimento das plântulas. Abstract in english Pre-harvest desiccation of soybean plants with glyphosate has been routinely conducted by seed producers, although it is not recommended because it may reduce seed physiological quality. The objective of this study was to evaluate the effects of the pre-harvest desiccation of plants with glyphosate [...] on the physiological quality of soybean seeds harvested at two different periods after application. The experimental design was completely randomized blocks, with four replications and subdivided plots. Main plots consisted of the presence and absence of a pre-harvest desiccation of soybean plants with glyphosate at the R7 stage, and subplots of seeds harvested 7 and 14 days after application. Moisture content, mechanical damage, viability, weight of 100 seeds, protein content and accumulation of glyphosate residues were determined after harvest. Physiological quality was evaluated by tests for germination, accelerated aging, electrical conductivity, seedling length and seedling dry matter. Pre-harvest desiccation of soybean plants with glyphosate reduces seed germination and seedling development. Delayed harvesting reduces the germination of soybean seeds produced by plants desiccated with glyphosate, but minimizes phytotoxicity in seedling development.

Mariana Zampar, Toledo; Cláudio, Cavariani; José de Barros, França-Neto.

92

Qualidade fisiológica de sementes de soja colhidas em duas épocas após dessecação com glyphosate Physiological quality of soybean seeds harvested at two periods after glyphosate desiccation  

Directory of Open Access Journals (Sweden)

Full Text Available A dessecação de plantas de soja em pré-colheita com glyphosate vem se tornando prática rotineira entre os produtores, apesar de não ser recomendada, pois pode comprometer a qualidade fisiológica das sementes. Objetivou-se avaliar os efeitos da dessecação das plantas em pré-colheita com glyphosate na qualidade fisiológica de sementes de soja colhidas em duas épocas após a aplicação. O delineamento experimental foi em blocos ao acaso, com quatro repetições, em esquema de parcelas subdivididas. As parcelas principais consistiram da dessecação ou não das plantas de soja com glyphosate em pré-colheita, no estádio R7, e as subparcelas da colheita das sementes 7 e 14 dias após a aplicação. As sementes foram avaliadas quanto ao teor de água, dano mecânico, viabilidade, massa de 100 sementes e teor de proteína. A qualidade fisiológica foi avaliada por meio dos testes de germinação, envelhecimento acelerado, condutividade elétrica, comprimento de plântulas e massa da matéria seca das plântulas. A dessecação das plantas de soja em pré-colheita com glyphosate ocasiona redução da germinação das sementes e do desenvolvimento inicial das plântulas. O atraso na colheita reduz a germinação das sementes oriundas de plantas de soja dessecadas com glyphosate em pré-colheita, mas minimiza os efeitos fitotóxicos no desenvolvimento das plântulas.Pre-harvest desiccation of soybean plants with glyphosate has been routinely conducted by seed producers, although it is not recommended because it may reduce seed physiological quality. The objective of this study was to evaluate the effects of the pre-harvest desiccation of plants with glyphosate on the physiological quality of soybean seeds harvested at two different periods after application. The experimental design was completely randomized blocks, with four replications and subdivided plots. Main plots consisted of the presence and absence of a pre-harvest desiccation of soybean plants with glyphosate at the R7 stage, and subplots of seeds harvested 7 and 14 days after application. Moisture content, mechanical damage, viability, weight of 100 seeds, protein content and accumulation of glyphosate residues were determined after harvest. Physiological quality was evaluated by tests for germination, accelerated aging, electrical conductivity, seedling length and seedling dry matter. Pre-harvest desiccation of soybean plants with glyphosate reduces seed germination and seedling development. Delayed harvesting reduces the germination of soybean seeds produced by plants desiccated with glyphosate, but minimizes phytotoxicity in seedling development.

Mariana Zampar Toledo

2012-01-01

93

Resposta de diferentes populações de Digitaria insularis ao herbicida glyphosate Response of different Digitaria insularis populations to glyphosate  

Directory of Open Access Journals (Sweden)

Full Text Available Objetivou-se com estse trabalho avaliar o controle químico de diferentes populações de capim-amargoso (Digitaria insularis pelo herbicida glyphosate por meio de curva de dose-resposta, além de propor tratamentos alternativos para as populações mais tolerantes. O delineamento experimental foi o de blocos ao acaso, com quatro repetições, em esquema fatorial 5 x 9. As sementes de capim-amargoso foram coletadas em cinco locais: área de produção de grãos da Fazenda de Ensino, Pesquisa e Produção da UNESP, Jaboticabal (SP; área de produção comercial de grãos, localizada nos municípios de Campo Florido-MG e Rio Verde-GO; pomar de laranja, localizado no município de Matão (SP; e área não agrícola sem histórico da aplicação de glyphosate (Jaboticabal-SP. O glyphosate (0D, 1/4D, 1/2D, D, 2D, 4D e 8D, em que D é a dose recomendada de 1,5 kg ha-1 de equivalente ácido e as suas associações [glyphosate + fluazifop-p-butil (1,5 + 0,25 kg ha-1 e glyphosate (1,5 kg ha-1 com sequencial de diuron + paraquat (0,20 + 0,40 kg ha-1 + 0,2% de surfatante] foram pulverizados em plantas de sete a oito perfilhos e altura média de 20 cm. As populações de capim-amargoso de Campo Florido e Rio Verde foram consideradas suscetíveis; as de Jaboticabal e Matão, tolerantes; e a da área não agrícola, de sensibilidade intermediária. A associação de glyphosate ao fluazifop ou a sua aplicação com sequencial de diuron + paraquat foram eficazes no controle das populações mais tolerantes de capim-amargoso.The objective of this study was to evaluate the chemical control of different sourgrass (Digitaria insularis populations by the herbicide glyphosate through dose-response curves, besides considering alternative treatments to control tolerant populations. A randomized block design was used with four replications, in a factorial scheme (5 x 9. Sourgrass seeds were colleted from five locations: a grain production area located at the educational, research and production farm of UNESP, Jaboticabal-SP; a grain production area located in the agricultural area of Campo Florido, MG, and Rio Verde, GO; citrus production area located in the agricultural area of Matão, SP, and an area without previous glyphosate application (Jaboticabal-SP. Glyphosate (0D, 1/4D, 1/2D, D, 2D, 4D and 8D, where D is the recommended rate of 1.5 kg ha-1 of acid equivalent and its associations [glyphosate plus fluazifop-p-butyl (1.5 plus 0.25 kg ha-1 and glyphosate (1.5 kg ha-1 in sequence with diuron plus paraquat (0.20 plus 0.40 kg ha-1 plus 0.2% of surfactant] were sprayed on the 7-8 tiller plants with average height of 20 cm. Campo Florido, MG and Rio Verde, GO sourgrass populations were considered susceptible; those of Jaboticabal-SP and Matão,SP were found to be tolerant and those from the nonagricultural area were considered of intermediate sensitivity. The association of glyphosate with fluazifop, or its application in sequence with diuron plus paraquat, were efficient in the control of sourgrass tolerant populations.

N.M Correia

2010-12-01

94

Resposta de diferentes populações de Digitaria insularis ao herbicida glyphosate / Response of different Digitaria insularis populations to glyphosate  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Objetivou-se com estse trabalho avaliar o controle químico de diferentes populações de capim-amargoso (Digitaria insularis) pelo herbicida glyphosate por meio de curva de dose-resposta, além de propor tratamentos alternativos para as populações mais tolerantes. O delineamento experimental foi o de b [...] locos ao acaso, com quatro repetições, em esquema fatorial 5 x 9. As sementes de capim-amargoso foram coletadas em cinco locais: área de produção de grãos da Fazenda de Ensino, Pesquisa e Produção da UNESP, Jaboticabal (SP); área de produção comercial de grãos, localizada nos municípios de Campo Florido-MG e Rio Verde-GO; pomar de laranja, localizado no município de Matão (SP); e área não agrícola sem histórico da aplicação de glyphosate (Jaboticabal-SP). O glyphosate (0D, 1/4D, 1/2D, D, 2D, 4D e 8D, em que D é a dose recomendada de 1,5 kg ha-1 de equivalente ácido) e as suas associações [glyphosate + fluazifop-p-butil (1,5 + 0,25 kg ha-1) e glyphosate (1,5 kg ha-1) com sequencial de diuron + paraquat (0,20 + 0,40 kg ha-1 + 0,2% de surfatante)] foram pulverizados em plantas de sete a oito perfilhos e altura média de 20 cm. As populações de capim-amargoso de Campo Florido e Rio Verde foram consideradas suscetíveis; as de Jaboticabal e Matão, tolerantes; e a da área não agrícola, de sensibilidade intermediária. A associação de glyphosate ao fluazifop ou a sua aplicação com sequencial de diuron + paraquat foram eficazes no controle das populações mais tolerantes de capim-amargoso. Abstract in english The objective of this study was to evaluate the chemical control of different sourgrass (Digitaria insularis) populations by the herbicide glyphosate through dose-response curves, besides considering alternative treatments to control tolerant populations. A randomized block design was used with four [...] replications, in a factorial scheme (5 x 9). Sourgrass seeds were colleted from five locations: a grain production area located at the educational, research and production farm of UNESP, Jaboticabal-SP; a grain production area located in the agricultural area of Campo Florido, MG, and Rio Verde, GO; citrus production area located in the agricultural area of Matão, SP, and an area without previous glyphosate application (Jaboticabal-SP). Glyphosate (0D, 1/4D, 1/2D, D, 2D, 4D and 8D, where D is the recommended rate of 1.5 kg ha-1 of acid equivalent) and its associations [glyphosate plus fluazifop-p-butyl (1.5 plus 0.25 kg ha-1) and glyphosate (1.5 kg ha-1) in sequence with diuron plus paraquat (0.20 plus 0.40 kg ha-1 plus 0.2% of surfactant)] were sprayed on the 7-8 tiller plants with average height of 20 cm. Campo Florido, MG and Rio Verde, GO sourgrass populations were considered susceptible; those of Jaboticabal-SP and Matão,SP were found to be tolerant and those from the nonagricultural area were considered of intermediate sensitivity. The association of glyphosate with fluazifop, or its application in sequence with diuron plus paraquat, were efficient in the control of sourgrass tolerant populations.

N.M, Correia; G.J, Leite; L.D, Garcia.

2010-12-01

95

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

Directory of Open Access Journals (Sweden)

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.

Changpeng Zhang

2015-01-01

96

Alteration in the cytokine levels and histopathological damage in common carp induced by glyphosate.  

Science.gov (United States)

Glyphosate is one of the most frequently used herbicides, and it has been demonstrated to generate a series of toxicological problems in animals and humans. However, relatively little is known about the effects of glyphosate on the immune system of fish. In the present study, the acute toxicity of glyphosate on common carp was first determined; then, the contents of interferon-? (IFN-?), interleukin-1? (IL-1?), and tumor necrosis factor -? (TNF-?) and histopathological alterations in the liver, kidneys, and spleen of common carp exposed to 52.08 or 104.15mgL(-1) of glyphosate for 168h were also determined and evaluated. The results of the acute toxicity tests showed that the 96h LC50 of glyphosate for common carp was 520.77mgL(-1). Moreover, sub-acute exposure of glyphosate altered the contents of IFN-?, IL-1?, and TNF-? in fish immune organs. For example, there was a remarkable increase in the IFN-? content in the kidneys, while there was a decrease in the liver and spleen. The IL-1? content increased in liver and kidneys, but it decreased in the spleen, and TNF-? mainly increased in the fish liver, kidneys, and spleen. In addition, glyphosate-exposure also caused remarkable histopathological damage in the fish liver, kidneys, and spleen. These results suggest that glyphosate-caused cytokine alterations may result in an immune suppression or excessive activation in the treated common carp as well as may cause immune dysfunction or reduced immunity. In conclusion, glyphosate has immunotoxic effects on common carp. PMID:25747155

Ma, Junguo; Li, Xiaoyu

2015-06-01

97

Degradation dynamics of glyphosate in different types of citrus orchard soils in China.  

Science.gov (United States)

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. PMID:25587790

Zhang, Changpeng; Hu, Xiuqing; Luo, Jinyan; Wu, Zhiyi; Wang, Li; Li, Bin; Wang, Yanli; Sun, Guochang

2015-01-01

98

Changes in the accumulation of shikimic acid in mycorrhized Capsicum annuum L. grown with application of glyphosate and phosphorus  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english When glyphosate is added to the soil, it is absorbed by roots and transported by xylem causing growth inhibition in plants. Mycorrhiza is the beneficial association between roots of most plants and soil fungi. The methylphosphonic group of the glyphosate could compete with inorganic phosphates for s [...] orption sites in the soil. The aim of this work was to study the effect of phosphorus availability and glyphosate residues in soil on pepper plant growth, and on physiological parameters, in plants non-inoculated or inoculated with Glomus mosseae or G. intraradices. The phytotoxic effects of the glyphosate were assessed by a bio-indicator as shikimic acid. At high doses, glyphosate (6.32 ?M) reduced root colonization, and this effect was increased by higher levels of phosphorus in the soil. The effects of herbicide on shikimic acid accumulation and on shoot growth began 24 hours after glyphosate treatments (HAT). At 24, 48, and 72 HAT, inoculated plants grown without glyphosate showed higher growth compared to the non-inoculated ones. At high glyphosate (6.32 ?M) and 96 HAT, the growth was completely inhibited. The shikimic acid accumulated in the upper leaves of non-inoculated plants, treated at 3.16 ?M glyphosate, was significantly higher at high P level, related to inoculated ones. These results suggest that the remobilization of glyphosate residues in the soil by the addition of phosphate should be considered a serious problem for crops in treated soils. The mycorrhization increases the pepper plant's tolerance to high glyphosate concentration in the substrate, and may allow support to this stress condition.

José, Beltrano; Marcela, Ruscitti; Cecilia, Arango; Marta, Ronco.

99

Glyphosate catabolism by Pseudomonas sp  

International Nuclear Information System (INIS)

The pathway for the degradation of glyphosate (N-phosphonomethylglycine) by Pseudomonas sp. PG2982 has been determined using metabolic radiolabeling experiments. Radiorespirometry experiments utilizing [3-14C] glyphosate revealed that approximately 50-59% of the C3 carbon was oxidized to CO2. Fractionation of stationary phase cells labeled with [3-14C]glyphosate revealed that from 45-47% of the assimilated C3 carbon is distributed to proteins and that amino acids methionine and serine are highly labeled. The nucleic acid bases adenine and guanine received 90% of the C3 label that was incorporated into nucleic acids, and the only pyrimidine base labeled was thymine. Pulse labeling of PG2982 cells with [3-14C]glyphosate revealed that [3-14C]sarcosine is an intermediate in glyphosate degradation. Examination of crude extracts prepared from PG2982 cells revealed the presence of an enzyme that oxidizes sarcosine to glycine and formaldehyde. These results indicate that the first step in glyphosate degradation by PG2982 is cleavage of the carbon-phosphorus bond, resulting in the release of sarcosine and a phosphate group. The phosphate group is utilized as a source of phosphorus, and the sarcosine is degraded to glycine and formaldehyde. Phosphonate utilization by Pseudomonas sp. PG2982 was investigated. Each of the ten phosphonates tested were utilized as a sole source of phosphorus by PG2982. Representative compounds torus by PG2982. Representative compounds tested included alkylphosphonates, 1-amino-substituted alkylphosphonates, amino-terminal phosphonates, and an arylphosphonate. PG2982 cultures degraded phenylphosphonate to benzene and produced methane from methylphosphonate. The data indicate that PG2982 is capable of cleaving the carbon-phosphorus bond of several structurally different phosphonates

100

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)

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 carried out in Piracicaba - SP, with applications of glyphosate (720 and 1440 g ha-1 alone or combined with two rates of ammonium sulfate (7.5 and 15.0 g L-1 or urea (2.5 and 5.0 g L-1, over the weeds Alternanthera tenella and Sorghum halepense. For the least susceptible species (S. halepense, the addition of nitrogen sources to the lower rate of glyphosate accelerated plant death, increasing the control levels up to 7.3%, at 21 days after application (DAA. However, the effects were not observed when control, fresh and dry mass were evaluated at 28 DAA. Glyphosate recommended rate for each species promoted appropriate control, without the need to add ammonium sulfate or urea.

S.J.P. Carvalho

2009-06-01

101

40 CFR 180.364 - Glyphosate; tolerances for residues.  

Science.gov (United States)

...2010-07-01 2010-07-01 false Glyphosate; tolerances for residues. 180... Specific Tolerances § 180.364 Glyphosate; tolerances for residues. (a...Tolerances are established for residues of glyphosate N -(phosphonomethyl)glycine...

2010-07-01

102

Influence of glyphosate in planktonic and biofilm growth of Pseudomonas aeruginosa  

Scientific Electronic Library Online (English)

Full Text Available This study evaluated the impact of different concentrations of glyphosate (Rondup®) on planktonic and biofilm growth of P. aeruginosa. Aerobic and anaerobic cultures of P. aeruginosa ATCC®15442 inoculated in MHB + glyphosate (0.845 ppm, 1.690 ppm, 8.45 ppm, 16.90 ppm, 84.50 ppm, 169 ppm, 845 ppm, an [...] d 1690 ppm) and cultured in normoxia and anoxia, following their OD560nm every hour for 24 h. Biofilms of adapted cells were formed in the presence of glyphosate (0.845 to 1690 ppm) in normoxia and anoxia for 36 h. Glyphosate at concentrations higher than 84.5 ppm reduces the cell density of planktonic aerobic cultures (p 0.05), and more pronounced over 169 ppm. Anaerobic biofilms have their growth more readily favored (p

Ilana Schneider, Lima; Nicole Carmo, Baumeier; Rosimeire Takaki, Rosa; Patrícia Maria Stuelp, Campelo; Edvaldo Antonio Ribeiro, Rosa.

2014-09-01

103

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

Science.gov (United States)

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.

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

2014-07-01

104

The effect of glyphosate on import into a sink leaf of sugar beet  

International Nuclear Information System (INIS)

The basis for glyphosate inducted limitation of carbon import into developing leaves was studied in sugar beet. To separate the effects of the herbicide on export from those on import, glyphosate was supplied to a developing leaf from two exporting source leaves which fed the sink leaf. Carbon import into the sink leaf was determined by supplying 14CO2 to a third source leaf which also supplies carbon to the monitored sink leaf. Import into the sink leaf decreased within 2 to 3 h after glyphosate application, even though photosynthesis and export in the source leaf supplying 14C were unaffected. Reduced import into the sink leaf was accompanied by increased import by the tap root. Elongation of the sink leaf was only slightly decreased following arrival of glyphosate. Photosynthesis by the sink leaf was not inhibited. The results to data support the view that import is slowed by the inhibition of synthesis of structural or storage compounds in the developing leaves

105

INTERACTIONS OF GLYPHOSATE AND FOLIAR AMENDMENTS WITH IAA SYNTHESIS AND UREASE ACTIVITY BY RHIZOSPHERE BACTERIA OF GLYPHOSATE-RESISTANT SOYBEAN  

Science.gov (United States)

Increased use of glyphosate-resistant crops has raised concerns regarding the potential environmental impacts of glyphosate. Biostimulants (products containing micronutrients, selected microorganisms, and plant growth regulators) and liquid fertilizers applied with glyphosate may affect metabolic ac...

106

The impact of Eskoba, a glyphosate formulation, on the freshwater plankton community.  

Science.gov (United States)

This study analyzed the acute effects of a glyphosate-based herbicide (Eskoba) on the microalgae Chlorella vulgaris, the cladoceran Simocephalus vetulus, and the copepod Notodiaptomus conifer, and evaluated the recovery ability of the surviving micro-crustaceans. Survival, age of first reproduction, and fecundity were used as endpoints for S. vetulus, while survival and time to reach the adult stage were used as endpoints for N. conifer. The registered order of sensitivity was S. vetulus (48-hour effective concentration [EC50]: 21 mg/L) > C. vulgaris (72-hour EC50: 58.59 mg/ L) > N. conifer (48-hour EC50: 95 mg/L). Despite the growth of C. vulgaris stimulated after 24 hours of exposure to the commercial formulation of glyphosate Eskoba, it was inhibited after 48 hours by all the concentrations tested. In postexposure experiments, microcrustaceans reduced their life expectancy, S. vetulus decreased its fertility, and N. conifer inhibited its sexual maturity. In summary, it was demonstrated that these species lost their recovery ability. PMID:25654931

Reno, U; Gutierrez, M F; Regaldo, L; Gagneten, A M

2014-12-01

107

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 ...

108

Glyphosate translocation in herbicide tolerant plants Translocação do glyphosate em plantas tolerantes ao herbicida  

OpenAIRE

The objective of this study was to evaluate glyphosate translocation in glyphosate-tolerant weed species (I. nil, T. procumbens and S. latifolia) compared to glyphosate-susceptible species (B. pilosa). The evaluations of 14C-glyphosate absorption and translocation were performed at 6, 12, 36 and 72 hours after treatment (HAT) in I. nil and B. pilosa, and only at 72 HAT in the species T. procumbens and S. latifolia. The plants were collected and fractionated into application leaf, other leaves...

Galon, L.; Ferreira, E. A.; Aspiazu?, I.; Concenc?o, G.; Silva, A. F.; Silva, A. A.; Vargas, L.

2013-01-01

109

Volunteer Glyphosate and Glufosinate Resistant Corn Competitiveness and Control in Glyphosate and Glufosinate Resistant Corn  

OpenAIRE

Glyphosate and glufosinate resistant (RR/LL) volunteer corn has become a problem when hybrid RR/LL corn follows hybrid RR/LL corn in the rotation. A total of six field trials were conducted over a three-year period (2008 to 2010) in southwestern Ontario to 1) evaluate the competitiveness of volunteer RR/LL corn in hybrid RR/LL corn, and 2) determine how to control volunteer RR/LL corn in hybrid RR/LL corn. The predicted volunteer RR/LL corn density to reduce hybri...

Nader Soltani; Christy Shropshire; Sikkema, Peter H.

2014-01-01

110

SIMULATED GLYPHOSATE DRIFT INFLUENCES NITRATE ASSIMILATION AND NITROGEN FIXATION IN NON-GLYPHOSATE RESISTANT SOYBEAN  

Science.gov (United States)

Non-target injury to conventional crops from glyphosate drift is a concern among growers using non-glyphosate-resistant (non-GR) cultivars. The effects of glyphosate drift on nitrate assimilation and nitrogen fixation potential, nodule mass, and yield of non-GR soybean were assessed in a field trial...

111

RDX-based nanocomposite microparticles for significantly reduced shock sensitivity  

International Nuclear Information System (INIS)

Cyclotrimethylenetrinitramine (RDX)-based nanocomposite microparticles were produced by a simple, yet novel spray drying method. The microparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and high performance liquid chromatography (HPLC), which shows that they consist of small RDX crystals (?0.1-1 ?m) uniformly and discretely dispersed in a binder. The microparticles were subsequently pressed to produce dense energetic materials which exhibited a markedly lower shock sensitivity. The low sensitivity was attributed to small crystal size as well as small void size (?250 nm). The method developed in this work may be suitable for the preparation of a wide range of insensitive explosive compositions.

112

Reducing the temperature sensitivity of SOI waveguide-based biosensors  

OpenAIRE

Label-free photonic biosensors fabricated on silicon-on-insulator (SOI) can provide compact size, high evanescent field strength at the silicon waveguide surface, and volume fabrication potential. However, due to the large thermo optic coefficient of water-based biosamples, the sensors are temperature-sensitive. Consequently, active temperature control is usually used. However, for low cost applications, active temperature control is often not feasible. Here, we use the opposite polarity of t...

Gylfason, Kristinn B.; Mola Romero, Albert; Sohlstro?m, Hans

2012-01-01

113

ADSORPTION OF GLYPHOSATE AND AMPAIN AGRICULTURAL SOILS  

OpenAIRE

Immediately after application glyphosate is mostly adsorbed in the upper 2 cm of soils, and is then transported and adsorbed after few days in deeper soil horizons with concomitant increasing content of its metabolite aminomethylphosphonic acid (AMPA). This work confirmed previous studies, where Fe-oxides seem to play a major role in the adsorption of glyphosate and AMPA in soils:  the Chernozem featured lower contents of Fed and Feo, with consequently lower adsorption of glyphosate and AMPA...

Nicola Rampazzo; Gorana Rampazzo Todorovic; Axel Mentler

2013-01-01

114

Water use efficiency by coffee arabica after glyphosate application / Eficiência do uso da água pelo cafeeiro arábica após aplicação de glyphosate  

Scientific Electronic Library Online (English)

Full Text Available Muitos cafeicultores utilizam o glyphosate em aplicações dirigidas. Nessas aplicações são constatados intoxicações. Através do efeito negativo direto na fotossíntese, ou indiretamente, reduzindo da taxa metabólica da planta, acredita-se que possam influenciar a eficiência do uso da água. Objetivou-s [...] e no trabalho averiguar as variáveis relacionadas ao uso da água entre cultivares de café submetidos a aplicação de subdoses de glyphosate e os efeitos de cada dose. O experimento foi conduzido em casa de vegetação utilizando-se três cultivares de cafeeiro (Coffea arabica): Acaiá (MG-6851), Catucaí Amarelo (2 SL) e Topázio (MG-1190) e, três subdoses do glyphosate (0,0; 115,2 e 460,8 g ha-1 do equivalente ácido), em esquema fatorial 3 x 3. Aos 15 DAA observou-se redução da condutância estomática. Constatou-se menor taxa de transpiração e eficiência do uso da água na quarta folha aos 15 dias após a aplicação. 45 dias após aplicação ocorreu queda da transpiração, sendo que, o Acaiá apresentou redução com aplicação de 115,2 g ha-1. O glyphosate reduziu a eficiência do uso da água, apresentando efeitos transitórios, mas que podem causar atraso no crescimento e produção do cafeeiro. O cultivar Acaiá foi o mais tolerante ao glyphosate, não alterando sua eficiência do uso da água com aplicação do herbicida. Abstract in english 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 thi [...] s 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.

Felipe Paolinelli de, Carvalho; André Cabral, França; Bruna Pereira de, Souza; Cíntia Maria Teixeira, Fialho; José Barbosa dos, Santos; Antonio Alberto da, Silva.

2014-09-01

115

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

Science.gov (United States)

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. PMID:20839871

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

2011-06-01

116

Control of glyphosate resistant hairy fleabane (Conyza bonariensis with dicamba and 2,4-D Controle de buva (Conyza bonariensis resistente ao glyphosate com dicamba e 2,4-D  

Directory of Open Access Journals (Sweden)

Full Text Available Auxyn type herbicides such as dicamba and 2,4-D are alternative herbicides that can be used to control glyphosate-resistant hairy fleabane. With the forthcoming possibility of releasing dicamba-resistant and 2,4-D-resistant crops, use of these growth regulator herbicides will likely be an alternative that can be applied to the control of glyphosate resistant hairy fleabane (Conyza bonariensis. The objective of this research was to model the efficacy, through dose-response curves, of glyphosate, 2,4-D, isolated dicamba and glyphosatedicamba combinations to control a brazilian hairy fleabane population resistant to glyphosate. The greenhouse dose-response studies were conducted as a completely randomized experimental design, and the rates used for dose response curve construction were 0, 120, 240, 480, 720 and 960 g a.i. ha-1 for 2,4-D, dicamba and the dicamba combination, with glyphosate at 540 g a.e. ha-1. The rates for glyphosate alone were 0, 180, 360, 540, 720 and 960 g a.e. ha-1. Herbicides were applied when the plants were in a vegetative stage with 10 to 12 leaves and height between 12 and 15 cm. Hairy fleabane had low sensitivity to glyphosate, with poor control even at the 960 g a.e. ha-1 rate. Dicamba and 2,4-D were effective in controlling the studied hairy fleabane. Hairy fleabane responds differently to 2,4-D and dicamba. The combination of glyphosate and dicamba was not antagonistic to hairy fleabane control, and glyphosate may cause an additive effect on the control, despite the population resistance.Os herbicidas mimetizadores de auxinas como dicamba e 2,4-D são alternativas para o controle de buva resistente ao glyphosate. Com a possível futura liberação comercial de culturas resistentes ao dicamba e 2,4-D, a aplicação destes herbicidas reguladores de crescimento será uma provável alternativa de controle de buva resistente ao glyphosate. O objetivo desta pesquisa foi modelar por meio de curvas de dose-resposta a eficácia do dicamba e 2,4-D isolados e dicamba em associação com glyphosate para controle de uma população de buva resistente. Um estudo de doseresposta em casa de vegetação foi conduzido em delineamento experimental inteiramente casualizado, sendo que as doses utilizadas para a construção das curvas de dose-resposta foram de 0, 120, 240, 480, 720 e 960 g i.a. ha-1de para o dicamba e o 2,4-D isolados e dicamba associado com 540 g e.a. ha-1 de glyphosate. As doses utilizadas para o glyphosate isolado foram de 0, 180, 360, 540, 720 e 960 g e.a. ha-1. Os tratamentos herbicidas foram aplicados quando asplantas estavam no estádio vegetativo de 10 a 12 folhas e altura entre 12 e 15 cm. A buva apresentou baixa sensibilidade ao glyphosate, pois não foi controlada mesmo na dose de 960 g e.a. ha-1 de glyphosate. O dicamba e o 2,4-D foram eficazes no controle da população de buva estudada. A buva responde de forma diferenciada ao 2,4-D e dicamba e será importante determinaras doses apropriadas de cada herbicida para controle de buva resistente ao glyphosate em condições de campo. A associação de glyphosate e dicamba não foi antagônica no controle da buva e o glyphosate pode causar um efeito aditivo no controle, apesar da resistência da população.

D.J. Soares

2012-06-01

117

Identification of regulated genes conferring resistance to high concentrations of glyphosate in a new strain of Enterobacter.  

Science.gov (United States)

Glyphosate is a widely used herbicide that inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) activity. Most plants and microbes are sensitive to glyphosate. However, transgenic-resistant crops that contain a modified epsps obtained from the resistant microbes have been commercially successful and therefore, new resistance genes and their adaptive regulatory mechanisms are of great interest. In this study, a soil-borne, glyphosate-resistant bacterium was selected and identified as Enterobacter. The EPSPS in this strain was found to have been altered to a resistant one. A total of 42 differentially expressed genes (DEGs) in the glyphosate were screened using microarray techniques. Under treatment, argF, sdhA, ivbL, rrfA-H were downregulated, whereas the transcripts of speA, osmY, pflB, ahpC, fusA, deoA, uxaC, rpoD and a few ribosomal protein genes were upregulated. Data were verified by quantitative real-time PCR on selected genes. All transcriptional changes appeared to protect the bacteria from glyphosate and associated osmotic, acidic and oxidative stresses. Many DEGs may have the potential to confer resistance to glyphosate alone, and some may be closely related to the shikimate pathway, reflecting the complex gene interaction network for glyphosate resistance. PMID:24237416

Fei, Yun-Yan; Gai, Jun-Yi; Zhao, Tuan-Jie

2013-12-01

118

Buva (Conyza bonariensis resistente ao glyphosate na região sul do Brasil Conyza bonariensis biotypes resistant to the glyphosate in southern Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available O glyphosate é um herbicida não-seletivo utilizado para controlar plantas daninhas há mais de 20 anos no Rio Grande do Sul. A buva (Conyza bonariensis é uma espécie daninha comum nos Estados da região Sul do Brasil e tradicionalmente controlada com uso de glyphosate. Entretanto, nos últimos anos plantas de buva têm apresentado poucos sintomas de toxicidade em resposta ao tratamento com glyphosate, sugerindo que estas plantas são resistentes ao herbicida. Assim, com o objetivo de avaliar a resposta de uma população de plantas de buva a glyphosate, foram realizados três experimentos: um em campo e dois em casa de vegetação. No experimento em campo, os tratamentos avaliados constaram de doses crescentes de glyphosate (0, 360, 720, 1.440, 2.880 e 5.760 g ha-1, e os herbicidas paraquat (400 g ha-1 e 2,4-D (1.005 g ha-1 foram empregados como produtos testemunhas, com diferentes mecanismos de ação nas plantas. No experimento em casa de vegetação os tratamentos constaram de doses crescentes de glyphosate (0, 360, 720, 1.440, 2.880 e 5.760 g ha-1, mais os herbicidas testemunhas, aplicados sobre plantas de um biótipo considerado resistente e de outro considerado sensível. No segundo experimento realizado em casa de vegetação, foram avaliados os tratamentos contendo glyphosate (720, 1.440 e 2.880 g ha-1, mais os herbicidas chlorimuron-ethyl (40 g ha-1, metsulfuron-methyl (4 g ha-1, 2,4-D (1.005 g ha-1, paraquat (400 g ha-1 e diuron + paraquat (200 + 400 g ha-1, bem como a testemunha sem tratamento herbicida. A toxicidade dos tratamentos herbicidas foi avaliada aos 7, 15 e 30 DAT (dias após tratamento. Os resultados obtidos nos experimentos em condições de campo e em casa de vegetação, de forma geral, evidenciam que o biótipo sensível é controlado pelo glyphosate e pelos demais herbicidas avaliados. Demonstram ainda que o biótipo resistente apresenta-se, igualmente ao biótipo sensível, altamente suscetível aos herbicidas com mecanismo de ação distinto daquele do glyphosate. Entretanto, o biótipo resistente mostra baixa resposta ao herbicida glyphosate, mesmo se este for empregado em doses elevadas, evidenciando ter adquirido resistência a esse produto.Glyphosate is a non-selective herbicide used for over 20 years to control weeds in Rio Grande do Sul. Horseweed (Conyza bonariensis is a common weed in Rio Grande do Sul and traditionally sensitive to glyphosate. However, during the last years, some horseweed plants have not shown significant injury symptoms after treatment with glyphosate, suggesting that they are resistant to this herbicide. Aiming to evaluate the response of a population of horseweed plants to glyphosate, one field and two greenhouse experiments were carried out. The field experiment treatment had increasing rates of glyphosate (0, 360, 720, 1,440, 2,880 and 5,760 g ha-1, and also the herbicides paraquat and 2,4-D as standards. The greenhouse experiments had increasing rates of glyphosate (0, 360, 720, 1,440, 2,880 and 5,760 g 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, the treatments were increasing rates of glyphosate (720, 1,440 and 2,880 g ha-1 and herbicides chlorimuron-ethyl, metsulfuron-methyl, 2,4-D, paraquat and diuron + paraquat sprayed on plants of resistant and susceptible biotypes. Horseweed control was accessed at 7, 15 and 30 DAT (days after treatment. Overall results of the field and greenhouse experiments provided evidence that the susceptible biotype is easily controlled by glyphosate and the other tested herbicides. In addition, the results demonstrated that the resistant biotype, as the susceptible biotype, is highly sensitive to herbicides with mode of action that differs from glyphosate. However, the resistant biotype showed low response to glyphosate, even at very high rates, confirming resistance of this horseweed population to glyphosate.

L. Vargas

2007-09-01

119

Residual herbicides in weed management for glyphosate-resistant soybean in Brazil / Herbicidas residuais em manejo de plantas daninhas na soja resistente ao glyphosate no Brasil  

Scientific Electronic Library Online (English)

Full Text Available Em sistemas de produção agrícola onde a cultura da soja tolerante ao glyphosate (Glycine max) está inserida e onde não há a prática de rotação de culturas com herbicidas alternativos, o uso exclusivo e contínuo do glyphosate tem levado ao surgimento de populações de plantas daninhas resistentes, que [...] podem limitar ou comprometer os benefícios dessa tecnologia. Nesse sentido, a eficiência de programas de manejo que envolvem herbicidas residuais (sulfentrazone, flumioxazin, imazethapyr, diclosulam, chlorimuron e s-metolachlor) aplicados na pré-emergência seguidos de glyphosate na pós-emergência da cultura (PRE-POST) foi comparada à de programas com apenas glyphosate na pós-emergência ? POST. O estudo constituiu-se de nove experimentos realizados durante as safras agrícolas 2009/2010 e 2010/2011. Os programas PRE-POST foram eficientes no controle de Amaranthus viridis, Brachiaria plantaginea, Bidens pilosa, Commelina benghalensis, Eleusine indica, Euphorbia heterophylla e Raphanus raphanistrum, sendo semelhantes aos níveis de controle do programa com duas aplicações de glyphosate POST. Alguns programas PRE-POST não foram eficientes para Cenchrus echinatus, Ipomoea hederifolia e Ipomoea triloba. Sulfentrazone e diclosulam PRE-POST melhoraram o controle de Ipomoea triloba em relação às aplicações sequenciais de glyphosate. Quanto à produtividade, não foram observadas diferenças significativas entre os tratamentos herbicidas. As aplicações de herbicidas residuais em pré-emergência seguidos da aplicação de glyphosate em pós-emergência resultam em controles consistentes de plantas daninhas e evitam a competição inicial. Além disso, estes programas utilizam pelo menos dois modos de ação que contribuem para a diversidade do uso de herbicidas que será necessária para ficar à frente de novos casos de resistência, independentemente de quando as plantas daninhas possam aparecer. Abstract in english In agricultural production systems where the glyphosate-resistant soybean crop (Glycine max) is grown and the practice of crop rotation with alternative herbicides is not adopted, the exclusive and continuous use of glyphosate has led to the occurrence of resistant weed populations that may limit or [...] compromise the benefits of this technology. Thus, the efficacy of weed management programs, including the use of residual herbicides (sulfentrazone, flumioxazin, imazethapyr, diclosulan, chlorimuron and s-metolachlor) applied in preemergence and followed by in-crop postemergence applications of glyphosate (PRE-POST) were compared to glyphosate postemergence only programs - POST. The study was conducted across nine locations during the 2009/2010 and 2010/2011 growing seasons. PRE-POST programs were efficient in the control of Amaranthus viridis, Brachiaria plantaginea, Bidens pilosa, Commelina benghalensis, Eleusine indica, Euphorbia heterophylla and Raphanus raphanistrum, with the level of control being similar when comparing the program with two applications of glyphosate POST. Some PRE-POST programs were not efficient in controlling Cenchrus echinatus, Ipomoea hederifolia and Ipomoea triloba. Sulfentrazone and diclosulam PRE-POST programs improved the control of Ipomoea triloba compared to sequential applications of glyphosate alone. No significant differences in soybean yield were observed between any of the herbicide treatments or study locations. The use of residual herbicides in preemergence followed by glyphosate in-crop postemergence provides consistent weed control and reducing early season weed competition. Furthermore, these programs utilize at least two herbicide modes of action for herbicide use diversity, which will be needed to stay ahead of resistance build-up, regardless of when weeds may appear.

R.F., Lopes Ovejero; D.J., Soares; W.S., Oliveira; L.B., Fonseca; G.U., Berger; J.K., Soteres; P.J., Christoffoleti.

2013-12-01

120

Glyphosate-Degrading Microorganisms from Industrial Activated Sludge  

OpenAIRE

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.

Balthazor, Terry M.; Hallas, Laurence E.

1986-01-01

121

Análisis de la sensibilidad de biotipos de Lolium multiflorum a herbicidas inhibidores de la enzima ALS, ACCasa y Glifosato Sensitivity analysis of Lolium multiflorum biotypes to Glyphosate, ACCase and ALS-inhibiting herbicides  

Directory of Open Access Journals (Sweden)

Full Text Available A pesar de los avances logrados en el control de las malezas con el uso de herbicidas, el manejo de las mismas no se simplificó, sino que, al contrario, surgieron nuevos desafíos, como la aparición de resistencia a herbicidas. En 2007, se reportó en Lolium multiflorum el segundo caso de resistencia a glifosato detectado en Argentina. En el sudeste de la provincia de Buenos Aires se registraron fallas de control a campo en poblaciones de Lolium multiflorum debido a su resistencia a distintos herbicidas de las familias de los inhibidores de ALS y de ACCasa y al herbicida glifosato. El objetivo de este estudio fue caracterizar el nivel de resistencia a ciertos herbicidas inhibidores de la ALS y de la ACCasa y al glifosato en una población de L. multiflorum de Lobería (Bs As, Argentina supuestamente resistente (LmR. Se realizaron bioensayos en cajas de Petri y se determinó la GR50 mediante la variación en la longitud de coleoptile. Las curvas de dosis-respuesta se obtuvieron por medio de la ecuación log-logística. El biotipo LmR presentó resistencia múltiple a herbicidas con tres modos de acción diferentes: glifosato, inhibidores de ALS y de ACCasa. Dicho ensayo demostró la aparición de un biotipo de L. multiflorum con resistencia a múltiples principios activos.Despite progress in weed control using herbicides, management has not been simplified, but new challenges such as herbicides resistance have arisen. In 2007, a Lolium multiflorum population resistant to glyphosate was reported, as the second case of glyphosate resistant weeds in Argentina. In the southeast of Buenos Aires province, control failures in populations of L. multiflorum to different families of herbicide such as ALS and ACCase inhibitors and to glyphosate at field level have been registered. The aim of this study was to characterize the level of resistance to certain herbicides inhibitors of ALS, ACCase and glyphosate in a putatively resistant (LmR population of L. multiflorum of Loberia (Buenos Aires, Argentina. Bioassays were conducted in Petri dishes and the GR50 was determined by the length of coleoptile. Curves dose-response were obtained using the log-logistic equation. The LmR biotype survived under multiple herbicides of three different modes of action, glyphosate, ALS and ACCase inhibitors. This test showed the appearance of a biotype of L. multiflorum with resistance to multiple active ingredients.

P. Diez De Ulzurrun

2012-09-01

122

Análisis de la sensibilidad de biotipos de Lolium multiflorum a herbicidas inhibidores de la enzima ALS, ACCasa y Glifosato / Sensitivity analysis of Lolium multiflorum biotypes to Glyphosate, ACCase and ALS-inhibiting herbicides  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Spanish Abstract in spanish A pesar de los avances logrados en el control de las malezas con el uso de herbicidas, el manejo de las mismas no se simplificó, sino que, al contrario, surgieron nuevos desafíos, como la aparición de resistencia a herbicidas. En 2007, se reportó en Lolium multiflorum el segundo caso de resistencia [...] a glifosato detectado en Argentina. En el sudeste de la provincia de Buenos Aires se registraron fallas de control a campo en poblaciones de Lolium multiflorum debido a su resistencia a distintos herbicidas de las familias de los inhibidores de ALS y de ACCasa y al herbicida glifosato. El objetivo de este estudio fue caracterizar el nivel de resistencia a ciertos herbicidas inhibidores de la ALS y de la ACCasa y al glifosato en una población de L. multiflorum de Lobería (Bs As, Argentina) supuestamente resistente (LmR). Se realizaron bioensayos en cajas de Petri y se determinó la GR50 mediante la variación en la longitud de coleoptile. Las curvas de dosis-respuesta se obtuvieron por medio de la ecuación log-logística. El biotipo LmR presentó resistencia múltiple a herbicidas con tres modos de acción diferentes: glifosato, inhibidores de ALS y de ACCasa. Dicho ensayo demostró la aparición de un biotipo de L. multiflorum con resistencia a múltiples principios activos. Abstract in english Despite progress in weed control using herbicides, management has not been simplified, but new challenges such as herbicides resistance have arisen. In 2007, a Lolium multiflorum population resistant to glyphosate was reported, as the second case of glyphosate resistant weeds in Argentina. In the so [...] utheast of Buenos Aires province, control failures in populations of L. multiflorum to different families of herbicide such as ALS and ACCase inhibitors and to glyphosate at field level have been registered. The aim of this study was to characterize the level of resistance to certain herbicides inhibitors of ALS, ACCase and glyphosate in a putatively resistant (LmR) population of L. multiflorum of Loberia (Buenos Aires, Argentina). Bioassays were conducted in Petri dishes and the GR50 was determined by the length of coleoptile. Curves dose-response were obtained using the log-logistic equation. The LmR biotype survived under multiple herbicides of three different modes of action, glyphosate, ALS and ACCase inhibitors. This test showed the appearance of a biotype of L. multiflorum with resistance to multiple active ingredients.

P., Diez De Ulzurrun; M.I., Leaden.

2012-09-01

123

Latex glove disorders: a management strategy for reducing skin sensitivity.  

Science.gov (United States)

The use of latex gloves by health care workers has increased over recent years. Proteins within the latex gloves and chemical additives during the manufacturing process have been linked to allergic skin and systemic disorders. Evidence suggests that latex-related skin disorders are increasing. Unless more stringent measures to control prolonged contact with latex gloves are implemented, skin disorders will continue to increase. While employees have a professional responsibility to reduce longer contact with latex gloves and use other safer alternatives, employers may also contribute through better education provisions, more strict monitoring and control of glove usage and purchasing gloves that are safer. An Infection Control Nurse can support both employees and management by developing and supporting better education and guidance for glove usage and an Employee Health Nurse could provide better care and support to affected workers. Glove manufacturers should identify the level of each protein in their gloves, the health risks involved and undertake new research to produce more hypoallergenic gloves. Collaborative efforts among employees, employers, researchers and glove manufacturers are needed to prevent the spiraling latex health risks to health care workers getting worse. PMID:11982783

Chummun, N H

2002-05-01

124

Bioremediation of glyphosate-contaminated soils.  

Science.gov (United States)

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. PMID:20676632

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

2010-09-01

125

Influence of glyphosate and its formulation (Roundup[reg]) on the toxicity and bioavailability of metals to Ceriodaphnia dubia  

International Nuclear Information System (INIS)

This study examined the toxicological interaction between glyphosate (or its formulation, Roundup[reg]) and several heavy metals to a freshwater cladoceran, Ceriodaphnia dubia. We demonstrated that all binary combinations of Roundup[reg] and metals (Cd, Cu, Cr, Ni, Pb, Se and Zn) exhibited 'less than additive' mixture toxicity, with 48-h LC50 toxic unit>1. Addition of glyphosate alone could significantly reduce the acute toxicity of Ag, Cd, Cr, Cu, Ni, Pb and Zn (but not Hg and Se). The ratio between glyphosate and metal ions was important in determining the mitigation of metal toxicity by glyphosate. A bioaccumulation study showed that in the presence of glyphosate the uptake of some metals (e.g. Ag) was halted but that of others (e.g. Hg) was increased significantly. Therefore, our study strongly suggests that glyphosate and its commercial formulations can control the toxicity as well as the bioavailability of heavy metals in aquatic ecosystems where both groups of chemicals can co-occur. - Glyphosate can control the toxicity and bioavailability of many heavy metals in the aquatic environment

126

Influence of glyphosate and its formulation (Roundup[reg]) on the toxicity and bioavailability of metals to Ceriodaphnia dubia  

Energy Technology Data Exchange (ETDEWEB)

This study examined the toxicological interaction between glyphosate (or its formulation, Roundup[reg]) and several heavy metals to a freshwater cladoceran, Ceriodaphnia dubia. We demonstrated that all binary combinations of Roundup[reg] and metals (Cd, Cu, Cr, Ni, Pb, Se and Zn) exhibited 'less than additive' mixture toxicity, with 48-h LC50 toxic unit>1. Addition of glyphosate alone could significantly reduce the acute toxicity of Ag, Cd, Cr, Cu, Ni, Pb and Zn (but not Hg and Se). The ratio between glyphosate and metal ions was important in determining the mitigation of metal toxicity by glyphosate. A bioaccumulation study showed that in the presence of glyphosate the uptake of some metals (e.g. Ag) was halted but that of others (e.g. Hg) was increased significantly. Therefore, our study strongly suggests that glyphosate and its commercial formulations can control the toxicity as well as the bioavailability of heavy metals in aquatic ecosystems where both groups of chemicals can co-occur. - Glyphosate can control the toxicity and bioavailability of many heavy metals in the aquatic environment.

Tsui, Martin T.K. [Department of Biology, Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China); Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (China); Wang Wenxiong [Department of Biology, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (China); Chu, L.M. [Department of Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China)]. E-mail: leemanchu@cuhk.edu.hk

2005-11-15

127

Occurrence of glyphosate in water bodies derived from intensive agriculture in a tropical region of southern Mexico.  

Science.gov (United States)

Glyphosate is an agrochemical widely used to control weeds. However, glyphosate spreads to water bodies by spray-drift, run-off and leaching, potentially causing detrimental effects on non-target biota. There is no information on the occurrence of this herbicide in water bodies near crop fields in Mexico, although it is the most commonly used pesticide in this country. To fill this gap, we quantified glyphosate in water bodies from twenty-three locations, including natural protected areas and agricultural areas in southern Mexico, during the dry and the rainy seasons. We expected (1) higher concentrations during the dry season due to reduced dilution by precipitation and, (2) absence of glyphosate in the protected areas. In agreement with our expectation, concentration of glyphosate was higher during the dry season (up to 36.7 ?g/L). Nonetheless, glyphosate was detected in all samples-including natural protected areas. These results emphasize the need for an evaluation of the impact of glyphosate on native species as well as regulate its use. PMID:25011503

Ruiz-Toledo, Jovani; Castro, Ricardo; Rivero-Pérez, Norma; Bello-Mendoza, Ricardo; Sánchez, Daniel

2014-09-01

128

Buva (Conyza bonariensis) resistente ao glyphosate na região sul do Brasil / Conyza bonariensis biotypes resistant to the glyphosate in southern Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O glyphosate é um herbicida não-seletivo utilizado para controlar plantas daninhas há mais de 20 anos no Rio Grande do Sul. A buva (Conyza bonariensis) é uma espécie daninha comum nos Estados da região Sul do Brasil e tradicionalmente controlada com uso de glyphosate. Entretanto, nos últimos anos pl [...] antas de buva têm apresentado poucos sintomas de toxicidade em resposta ao tratamento com glyphosate, sugerindo que estas plantas são resistentes ao herbicida. Assim, com o objetivo de avaliar a resposta de uma população de plantas de buva a glyphosate, foram realizados três experimentos: um em campo e dois em casa de vegetação. No experimento em campo, os tratamentos avaliados constaram de doses crescentes de glyphosate (0, 360, 720, 1.440, 2.880 e 5.760 g ha-1), e os herbicidas paraquat (400 g ha-1) e 2,4-D (1.005 g ha-1) foram empregados como produtos testemunhas, com diferentes mecanismos de ação nas plantas. No experimento em casa de vegetação os tratamentos constaram de doses crescentes de glyphosate (0, 360, 720, 1.440, 2.880 e 5.760 g ha-1), mais os herbicidas testemunhas, aplicados sobre plantas de um biótipo considerado resistente e de outro considerado sensível. No segundo experimento realizado em casa de vegetação, foram avaliados os tratamentos contendo glyphosate (720, 1.440 e 2.880 g ha-1), mais os herbicidas chlorimuron-ethyl (40 g ha-1), metsulfuron-methyl (4 g ha-1), 2,4-D (1.005 g ha-1), paraquat (400 g ha-1) e diuron + paraquat (200 + 400 g ha-1), bem como a testemunha sem tratamento herbicida. A toxicidade dos tratamentos herbicidas foi avaliada aos 7, 15 e 30 DAT (dias após tratamento). Os resultados obtidos nos experimentos em condições de campo e em casa de vegetação, de forma geral, evidenciam que o biótipo sensível é controlado pelo glyphosate e pelos demais herbicidas avaliados. Demonstram ainda que o biótipo resistente apresenta-se, igualmente ao biótipo sensível, altamente suscetível aos herbicidas com mecanismo de ação distinto daquele do glyphosate. Entretanto, o biótipo resistente mostra baixa resposta ao herbicida glyphosate, mesmo se este for empregado em doses elevadas, evidenciando ter adquirido resistência a esse produto. Abstract in english Glyphosate is a non-selective herbicide used for over 20 years to control weeds in Rio Grande do Sul. Horseweed (Conyza bonariensis) is a common weed in Rio Grande do Sul and traditionally sensitive to glyphosate. However, during the last years, some horseweed plants have not shown significant injur [...] y symptoms after treatment with glyphosate, suggesting that they are resistant to this herbicide. Aiming to evaluate the response of a population of horseweed plants to glyphosate, one field and two greenhouse experiments were carried out. The field experiment treatment had increasing rates of glyphosate (0, 360, 720, 1,440, 2,880 and 5,760 g ha-1), and also the herbicides paraquat and 2,4-D as standards. The greenhouse experiments had increasing rates of glyphosate (0, 360, 720, 1,440, 2,880 and 5,760 g 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, the treatments were increasing rates of glyphosate (720, 1,440 and 2,880 g ha-1) and herbicides chlorimuron-ethyl, metsulfuron-methyl, 2,4-D, paraquat and diuron + paraquat sprayed on plants of resistant and susceptible biotypes. Horseweed control was accessed at 7, 15 and 30 DAT (days after treatment). Overall results of the field and greenhouse experiments provided evidence that the susceptible biotype is easily controlled by glyphosate and the other tested herbicides. In addition, the results demonstrated that the resistant biotype, as the susceptible biotype, is highly sensitive to herbicides with mode of action that differs from glyphosate. However, the resistant biotype showed low response to glyphosate, even at very high rates, confirming resistance of this hor

L., Vargas; M.A., Bianchi; M.A., Rizzardi; D., Agostinetto; T., Dal Magro.

2007-09-01

129

Suscetibilidade de duas Gramas-boiadeiras a diferentes formulações de glyphosate / Susceptibility of Cutgrass and Peruvian Watergrass to different glyphosate formulations  

Scientific Electronic Library Online (English)

Full Text Available A utilização do herbicida glyphosate para o controle químico das espécies de gramas-boiadeiras nas lavouras orizícolas não tem se mostrado eficiente. Nesse contexto, a investigação do controle dessas espécies com o glyphosate torna-se de fundamental importância, uma vez que não estão disponíveis no [...] mercado herbicidas seletivos para o controle dessas em pós-emergência na cultura do arroz irrigado. Em vista do exposto, o objetivo do presente estudo foi avaliar a suscetibilidade das gramas-boiadeiras a diferentes formulações de glyphosate. Foram conduzidos dois experimentos em casa de vegetação em esquema fatorial. No primeiro experimento, o fator A constituiu-se de duas formulações de glyphosate (sal potássico e isopropilamina) e o fator B de nove doses dos herbicidas (zero; 175; 350; 700; 1400; 2800; 5600; 11200; 22400g e.a. ha-1). No segundo experimento, o fator A constituiu-se de duas espécies de gramas-boiadeiras (Leersia hexandra e Luziola peruviana), o fator B de três formulações do glyphosate (sal amônio, potássico e isopropilamina) e o fator C de nove doses dos herbicidas (zero; 87,5; 175; 350; 700; 1400; 2800; 5600; 11200g e.a. ha-1). Com base nos resultados obtidos, foi possível observar que as espécies apresentaram diferença de suscetibilidade ao herbicida glyphosate. Além disso, Leersia hexandra foi mais sensível em comparação a Luziola peruviana. As formulações de glyphosate influenciaram na suscetibilidade das espécies ao controle, sendo que, Roundup Transorb R® e Roundup Ultra® proporcionam melhor controle das espécies de gramas-boiadeiras. Abstract in english The use of glyphosate to chemical control of Cutgrass and Peruvian Watergrass with the use of non-selective herbicides has not been efficient. In this context, the investigation of chemical control of these species to glyphosate is very important, since there are not available commercially selective [...] herbicides to control these species in post-emergence of irrigated rice. Therefore, the objective of this study was to evaluate the susceptibility of Cutgrass and Peruvian Watergrass to different formulations of glyphosate. Two factorial experiments were conducted in a greenhouse, in the first the A factor were two formulations of glyhposate (potassium and isopropylamine salt) and the B factor were nine doses of the herbicide (zero; 175; 350; 700; 1400; 2800; 5600; 11200; 22400g a.e. ha-1). In the second experiment, the A factor were two species (Leersia hexandra and Luziola peruviana), the B factor were three formulations of glyphosate (amoniun, potassium e isopropylamine salt) and the C factor were nine doses of herbicides (zero; 87,5; 175; 350; 700; 1400; 2800; 5600; 11200g a.e. ha-1). Based on the results obtained, it was observed that these species exhibit differential susceptibility to glyphosate. Moreover, Leersia hexandra was more sensitive when compared to Luziola peruviana. Glyphosate formulation influenced control efficiency, where Transorb Roundup R® and Roundup Ultra® provided the best control of the two species.

Ananda, Scherner; Luis Antonio de, Avila; Fábio, Schreiber; Nelson Diehl, Kruse; Dirceu, Agostinetto; Jesus Juares Oliveira, Pinto; Rodrigo Ribeiro, Pestana.

2014-03-01

130

Associação de glyphosate e imidazolinonas no controle de arroz-vermelho em arroz Clearfield® / Association of glyphosate and imidazolinones on red rice control in Clearfield™ rice  

Scientific Electronic Library Online (English)

Full Text Available O objetivo do presente trabalho foi o de avaliar os efeitos da utilização de glyphosate e herbicidas imidazolinonas, em aplicações isoladas ou associadas, sobre o controle de arroz-vermelho (Oryza sativa) e produtividade de grãos de arroz Clearfield®. O experimento foi conduzido a campo na safra 200 [...] 7/08, em Cachoeirinha, RS, Brasil, com delineamento em blocos ao acaso e tratamentos dispostos em arranjo fatorial (2x6), usando-se quatro repetições. O fator A constou de dois níveis do herbicida glyphosate, aplicados no subperíodo semeadura-emergência da cultura por ocasião do início da emissão do coleóptilo do arroz (ponto de agulha); o fator B constou de seis tratamentos com imazethapyr+imazapic, aplicados em associação ao glyphosate ou quando a cultura atingiu o estádio de três folhas expandidas. As três variáveis explicativas analisadas foram a população de plantas de arroz e arroz-vermelho, a eficácia do controle de arroz-vermelho e a produtividade de grãos da cultura. O uso de glyphosate no ponto de agulha reduziu em 75% a população do arroz-vermelho e aumentou em 40% a produtividade de grãos de arroz, em relação à testemunha. O uso isolado de herbicidas imidazolinonas e sua associação com o dessecante proporcionou controle eficaz do arroz-vermelho e incrementou a produtividade de grãos, em comparação à situação sem controle da infestante, independente da dose e do sistema de aplicação. Abstract in english The objective of this research was to evaluate the effects of the utilization of glyphosate and imidazolinones herbicides, in isolated or associated applications, on the effectiveness of red rice (Oryza sativa) control and grain yield of Clearfield-rice. The experiment was conducted under field cond [...] itions in 2007/08, in Cachoeirinha, RS, Brazil, using a randomized block design in a two-factorial design 2x6, with four replicates. The factor A was composed by two levels of glyphosate, applied during the subperiod between sowing and crop emergence at the early coleoptile stage of the rice plants; and the factor B consisted of six treatments with imazethapyr+imazapic, applied in association with glyphosate or when the rice crop plants had three expanded leaves. The crop and weed populations, red rice control and grain yield of crop were evaluated. The results show that the glyphosate application at the early coleoptile stage of the crop reduced 75% the red rice population and increased 40% the grain yield, in relation to the situation without weed control. The use of imidazolinones and their association with glyphosate provided effective control of red rice and increased the grain yield, independent of rates and application system.

Valmir Gaedke, Menezes; Carlos Henrique Paim, Mariot; Augusto, Kalsing; Thais Fernanda Stella de, Freitas; Daniel Santos, Grohs; Felipe de Oliveira, Matzenbacher.

2154-21-01

131

Nodulation and mycorrhization of transgenic soybean after glyphosate application  

Directory of Open Access Journals (Sweden)

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.

Aloisio Freitas Chagas Junior

2013-12-01

132

Glyphosate influence on the physiological parameters of Conyza bonariensis biotypes / Influência de glyphosate em parâmetros fisiológicos de biótipos de Conyza bonariensis  

Scientific Electronic Library Online (English)

Full Text Available Objetivou-se neste trabalho determinar alterações na fotossíntese e na inibição da EPSPs, com base no acúmulo de ácido chiquímico, em biótipos de buva resistente e suscetível ao glyphosate. Foram realizados dois experimentos, conduzidos em esquema bifatorial. No primeiro, avaliaram-se biótipos de bu [...] va (um resistente e outro suscetível ao glyphosate) e doses do herbicida (0 e 1.080ge.a.ha-1) aplicadas sobre a planta daninha. No segundo experimento, os biótipos de buva (resistente e suscetível ao glyphosate) foram avaliados em cinco épocas: 0, 3, 7, 10 e 14 dias após a aplicação do herbicida (DAH). Foram efetuadas determinações da taxa fotossintética, transpiração, eficiência da carboxilação e uso eficiente da água, empregando analisador de gases no infravermelho (IRGA), e a concentração de ácido chiquímico, determinada por HPLC. A aplicação do glyphosate afetou negativamente os parâmetros fotossintéticos do biótipo suscetível, causando total inibição da taxa fotossintética, da taxa transpiratória, da eficiência da carboxilação e da eficiência do uso da água, a partir dos 7DAH. Já para o biótipo resistente, não se observou total inibição dos parâmetros fotossintéticos. Em ambos os biótipos ocorreu acúmulo de ácido chiquímico após aplicação de glyphosate; contudo, o biótipo suscetível apresentou as maiores concentrações, indicando maior sensibilidade da enzima EPSPs. O acúmulo de ácido chiquímico no biótipo resistente indica que o mecanismo de resistência não está relacionado somente com a insensibilidade da EPSPs ao glyphosate e/ou que outros mecanismos de resistência podem estar envolvidos. Abstract in english The objective of this study was to determine changes in gas exchange and inhibition of EPSPs, based on the accumulation of shikimic acid in horseweed biotypes resistant and sensitive to glyphosate. Two experiments were conducted in a factorial model. The first one evaluated horseweed biotypes (one r [...] esistant and one susceptible to glyphosate), and herbicide rates (0 and 1,080 g a.e. ha ¹) applied on the weed. In the second experiment, the horseweed biotypes (susceptible and resistant to glyphosate) were evaluated in five periods as following: 0, 3, 7, 10, and 14 days after herbicide application (DAH). The photosynthetic rate, transpiration, carboxylation efficiency, and water efficiency were determined using an infrared gas analyzer (IRGA), and shikimic acid concentration by HPLC. The application of glyphosate damaged the photosynthetic parameters of the susceptible biotype, causing complete inhibition of the photosynthetic rate, transpiration rate, carboxylation efficiency and water use efficiency, starting from the 7 DAH. On the other hand, total inhibition of the photosynthetic parameters was not observed for the resistant biotype. Shikimic acid accumulation occurred in both biotypes after glyphosate application but the susceptible biotype had the highest concentrations, indicating greater sensitivity of the enzyme EPSPs. The accumulation of shikimic acid in the resistant biotype indicates that the mechanism of resistance is not related to the total insensitivity of the enzyme EPSPs to glyphosate and/or that other resistance mechanisms may be involved.

L., Vargas; D.R.O., Silva; D., Agostinetto; M.B., Matallo; F.M., Santos; S.D.B., Almeida; G., Chavarria; D.F.P., Silva.

2014-03-01

133

Reducing Glycosphingolipid Content in Adipose Tissue of Obese Mice Restores Insulin Sensitivity, Adipogenesis and Reduces Inflammation  

Science.gov (United States)

Adipose tissue is a critical mediator in obesity-induced insulin resistance. Previously we have demonstrated that pharmacological lowering of glycosphingolipids and subsequently GM3 by using the iminosugar AMP-DNM, strikingly improves glycemic control. Here we studied the effects of AMP-DNM on adipose tissue function and inflammation in detail to provide an explanation for the observed improved glucose homeostasis. Leptin-deficient obese (LepOb) mice were fed AMP-DNM and its effects on insulin signalling, adipogenesis and inflammation were monitored in fat tissue. We show that reduction of glycosphingolipid biosynthesis in adipose tissue of LepOb mice restores insulin signalling in isolated ex vivo insulin-stimulated adipocytes. We observed improved adipogenesis as the number of larger adipocytes was reduced and expression of genes like peroxisome proliferator-activated receptor (PPAR) ?, insulin responsive glucose transporter (GLUT)-4 and adipsin increased. In addition, we found that adiponectin gene expression and protein were increased by AMP-DNM. As a consequence of this improved function of fat tissue we observed less inflammation, which was characterized by reduced numbers of adipose tissue macrophages (crown-like structures) and reduced levels of the macrophage chemo attractants monocyte-chemoattractant protein-1 (Mcp-1/Ccl2) and osteopontin (OPN). In conclusion, pharmacological lowering of glycosphingolipids by inhibition of glucosylceramide biosynthesis improves adipocyte function and as a consequence reduces inflammation in adipose tissue of obese animals. PMID:19305508

van Eijk, Marco; Aten, Jan; Bijl, Nora; Ottenhoff, Roelof; van Roomen, Cindy P. A. A.; Dubbelhuis, Peter F.; Seeman, Ingar; Ghauharali-van der Vlugt, Karen; Overkleeft, Hermen S.; Arbeeny, Cynthia; Groen, Albert K.; Aerts, Johannes M. F. G.

2009-01-01

134

The use of environmental metabolomics to determine glyphosate level of exposure in rapeseed (Brassica napus L.) seedlings  

Energy Technology Data Exchange (ETDEWEB)

Metabolic profiling in plants can be used to differentiate between treatments and to search for biomarkers for exposure. A methodology for processing Ultra-High-Performance Liquid Chromatography-Diode-Array-Detection data is devised. This methodology includes a scheme for selecting informative wavelengths, baseline removal, retention time alignment, selection of relevant retention times, and principal component analysis (PCA). Plant crude extracts from rapeseed seedling exposed to sublethal concentrations of glyphosate are used as a study case. Through this approach, plants exposed to concentrations down to 5 {mu}M could be distinguished from the controls. The compounds responsible for this differentiation were partially identified and were different from those specific for high exposure samples, which suggests that two different responses to glyphosate are elicited in rapeseed depending on the level of exposure. The PCA loadings indicate that a combination of other metabolites could be more sensitive than the response of shikimate to detect glyphosate exposure. - Highlights: > A method for processing UHPLC-DAD data for plant metabolic profiling is devised. > The metabolic profiling approach is more sensitive to glyphosate exposure than shikimate. > Plants exposed to concentrations down to 5 {mu}M can be distinguished from the controls. > Two different responses to glyphosate may be elicited in rapeseed depending on the level of exposure. - A novel untargeted environmental metabololomic approach is used to detect low-level glyphosate exposure of rapeseed seedlings.

Petersen, Iben Lykke; Tomasi, Giorgio; Sorensen, Hilmer; Boll, Esther S.; Hansen, Hans Christian Bruun [Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C (Denmark); Christensen, Jan H., E-mail: jch@life.ku.dk [Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C (Denmark)

2011-10-15

135

The use of environmental metabolomics to determine glyphosate level of exposure in rapeseed (Brassica napus L.) seedlings  

International Nuclear Information System (INIS)

Metabolic profiling in plants can be used to differentiate between treatments and to search for biomarkers for exposure. A methodology for processing Ultra-High-Performance Liquid Chromatography-Diode-Array-Detection data is devised. This methodology includes a scheme for selecting informative wavelengths, baseline removal, retention time alignment, selection of relevant retention times, and principal component analysis (PCA). Plant crude extracts from rapeseed seedling exposed to sublethal concentrations of glyphosate are used as a study case. Through this approach, plants exposed to concentrations down to 5 ?M could be distinguished from the controls. The compounds responsible for this differentiation were partially identified and were different from those specific for high exposure samples, which suggests that two different responses to glyphosate are elicited in rapeseed depending on the level of exposure. The PCA loadings indicate that a combination of other metabolites could be more sensitive than the response of shikimate to detect glyphosate exposure. - Highlights: ? A method for processing UHPLC-DAD data for plant metabolic profiling is devised. ? The metabolic profiling approach is more sensitive to glyphosate exposure than shikimate. ? Plants exposed to concentrations down to 5 ?M can be distinguished from the controls. ? Two different responses to glyphosate may be elicited in rapeseed depending on the level of exposure. - A novel untargeted enviosure. - A novel untargeted environmental metabololomic approach is used to detect low-level glyphosate exposure of rapeseed seedlings.

136

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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. Abstract in english 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 effect [...] ive 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 stages. Three trials were developed under field conditions: in citrus orchards under formation, in plants with phenological stages of ten leaves and at pre-flowering. For plants at the ten leaf stage, satisfactory control was reached with applications of glyphosate + bromacil + diuron (1,440 + 1,200 + 1,200 g ha-1), glyphosate + atrazine (1,440 + 1,500 g ha-1) and glyphosate + diuron (1,440 + 1,500 g ha-1). For Conyza spp. plants at the pre-flowering stage, ammonium-glufosinate application, at the rate of 400 g ha-1, isolated or associated to MSMA, bromacil+diuron, metsulfuron, carfentrazone and paraquat, was a viable alternative to control glyphosate-resistant biotypes.

M.S., Moreira; M.S.C., Melo; S.J.P., Carvalho; M., Nicolai; P.J., Crhistoffoleti.

137

Oxidative stress responses of rats exposed to Roundup and its active ingredient glyphosate.  

Science.gov (United States)

Glyphosate is the active ingredient and polyoxyethyleneamine, the major component, is the surfactant present in the herbicide Roundup formulation. The objective of this study was to analyze potential cytotoxicity of the Roundup and its fundamental substance (glyphosate). Albino male rats were intraperitoneally treated with sub-lethal concentration of Roundup (269.9mg/kg) or glyphosate (134.95mg/kg) each 2 days, during 2 weeks. Hepatotoxicity was monitored by quantitative analysis of the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) activities, total protein, albumin, triglyceride and cholesterol. Creatinine and urea were used as the biochemical markers of kidney damages. The second aim of this study to investigate how glyphosate alone or included in herbicide Roundup affected hepatic reduced glutathione (GSH) and lipid peroxidation (LPO) levels of animals as an index of antioxidant status and oxidative stress, respectively, as well as the serum nitric oxide (NO) and alpha tumour necrosis factor (TNF-?) were measured. Treatment of animals with Roundup induced the leakage of hepatic intracellular enzymes, ALT, AST and ALP suggesting irreversible damage in hepatocytes starting from the first week. It was found that the effects were different on the enzymes in Roundup and glyphosate-treated groups. Significant time-dependent depletion of GSH levels and induction of oxidative stress in liver by the elevated levels of LPO, further confirmed the potential of Roundup to induce oxidative stress in hepatic tissue. However, glyphosate caused significant increases in NO levels more than Roundup after 2 weeks of treatment. Both treatments increased the level of TNF-? by the same manner. The results suggest that excessive antioxidant disruptor and oxidative stress is induced with Roundup than glyphosate. PMID:21784030

El-Shenawy, Nahla S

2009-11-01

138

A red and far-red light receptor mutation confers resistance to the herbicide glyphosate.  

Science.gov (United States)

Glyphosate is a widely applied broad-spectrum systemic herbicide that inhibits competitively the penultimate enzyme 5-enolpyruvylshikimate 3-phosphate synthase (EPSPS) from the shikimate pathway, thereby causing deleterious effects. A glyphosate-resistant Arabidopsis mutant (gre1) was isolated and genetic analyses indicated that a dysfunctional red (R) and far-red (FR) light receptor, phytochrome B (phyB), caused this phenotype. This finding is consistent with increased glyphosate sensitivity and glyphosate-induced shikimate accumulation in low R:FR light, and the induction of genes encoding enzymes of the shikimate pathway in high R:FR light. Expression of the shikimate pathway genes exhibited diurnal oscillation and this oscillation was altered in the phyB mutant. Furthermore, transcript analysis suggested that this diurnal oscillation was not only dependent on phyB but was also due to circadian regulatory mechanisms. Our data offer an explanation of the well documented observation that glyphosate treatment at various times throughout the day, with their specific composition of light quality and intensity, results in different efficiencies of the herbicide. PMID:24654847

Sharkhuu, Altanbadralt; Narasimhan, Meena L; Merzaban, Jasmeen S; Bressan, Ray A; Weller, Steve; Gehring, Chris

2014-06-01

139

Development of an oligopeptide functionalized surface plasmon resonance biosensor for online detection of glyphosate.  

Science.gov (United States)

We report a surface plasmon resonance (SPR) biosensor for online detection of glyphosate. The surface of the sensing element is decorated with an oligopeptide, TPFDLRPSSDTR, which is identified by using phage display library. This oligopeptide shows high binding specificity for glyphosate (KD = 8.6 ?M), probably because of the presence of R and D in the oligopeptide. To detect glyphosate in buffer solution, an SPR gold sensor chip is modified by using the oligopeptide with a surface density of 0.6 1/nm(2). The sensitivity of this oligopeptide-functionalized SPR biosensor is 1.02 RU/?M whereas the limit of detection (LOD) is 0.58 ?M. This oligopeptide functionalized SPR biosensor also shows good specificity against other analytes such as glycine, thiacloprid, and imidacloprid. PMID:23675691

Ding, Xiaokang; Yang, Kun-Lin

2013-06-18

140

Glyphosate adsorption in soils compared to herbicides replaced with the introduction of glyphosate resistant crops.  

Science.gov (United States)

Use of glyphosate resistant crops was helpful in addressing observed increases in environmental contamination by herbicides. Glyphosate is a broad-spectrum herbicide, and its behaviour-as well as that of other herbicides-in soils is an important consideration for the overall environmental evaluation of genetically resistant crop introduction. However, few data have been published comparing glyphosate behaviour in soil to that of the herbicides that would be replaced by introduction of glyphosate resistant crops. This work compares glyphosate adsorption in soil with that of other herbicides frequently used in rape (trifluralin and metazachlor), sugarbeet (metamitron) and corn (sulcotrione). Herbicide adsorption was characterised in surface soils and in the complete soils profiles through kinetics and isotherms using batch equilibration methods. Pedological and molecular structure factors controlling the adsorption of all five herbicides were investigated. Glyphosate was the most strongly adsorbed herbicide, thus having the weakest potential for mobility in soils. Glyphosate adsorption was dependent on its ionisable structure in relation to soil pH, and on soil copper, amorphous iron and phosphate content. Trifluralin adsorption was almost equivalent to glyphosate adsorption, whereas metazachlor, metamitron and sulcotrione adsorption were lower. Trifluralin, metazachlor and metamitron adsorption increased with soil organic carbon content. Sulcotrione was the least adsorbed herbicide in alkaline soils, but its adsorption increased when pH decreased. Ranking the adsorption properties among the five herbicides, glyphosate and trifluralin have the lowest availability and mobility in soils, but the former has the broadest spectrum for weed control. PMID:15951002

Mamy, Laure; Barriuso, Enrique

2005-11-01

141

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)

Full Text Available O glyphosate é um herbicida de amplo espectro utilizado há mais de 15 anos em pomares de maçã na região de Vacaria-RS, para manejo da vegetação nas linhas da cultura. São realizadas, em geral, três a quatro aplicações por ciclo e a dose normalmente utilizada é de 720 a 1.080 g e.a. ha-1 de glyphosate (2 a 3 L ha-1 do produto comercial. O azevém (Lolium multiflorum é uma planta daninha comum em pomares e, tradicionalmente, sensível ao glyphosate. Entretanto, nos últimos anos a ocorrência de plantas de azevém que, após receberem o tratamento com glyphosate, não manifestam sintomas significativos de toxicidade sugere que elas adquiriram resistência ao produto. Assim, com o objetivo de avaliar a resposta de uma população de plantas de azevém ao glyphosate, foram realizados três experimentos: um em campo e dois em casa de vegetação. No experimento em campo os tratamentos avaliados constaram de doses crescentes de glyphosate (0, 360, 720, 1.440, 2.880, 5.760 e 11.520 g e.a. ha-1, e os herbicidas paraquat, glufosinate, haloxyfop e diclofop foram empregados como produtos-padrão, aplicados em dois estádios vegetativos do azevém. No experimento em casa de vegetação, os tratamentos constaram de doses crescentes de glyphosate (0, 360, 720, 1.440, 2.880 e 5.760 g e.a. ha-1 mais os herbicidas testemunhas, aplicados sobre plantas do biótipo considerado resistente e de um sensível. No segundo experimento realizado em casa de vegetação foram avaliados tratamentos contendo glyphosate (720, 1.440, 2.880, 720 + 720 e 720 + 1.440 g e.a. ha-1, em aplicações únicas e seqüenciais, mais os herbicidas paraquat, glufosinate, haloxyfop, clethodim, sethoxydim, diclofop, fenoxaprop, fluazifop, paraquat + diuron, atrazine + simazine, trifluralin e metolachlor. A toxicidade dos tratamentos herbicidas foi avaliada aos 15, 30 e 45 DAT (dias após tratamento. Os resultados obtidos nos experimentos em campo e em casa de vegetação, de forma 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-ammonium, haloxyfop, clethodim, sethoxydim, diclofop-methyl, fenoxaprop, fluazifop, paraquat + diuron,

L. Vargas

2004-12-01

142

Sugarcane tolerance to ratoon eradication with glyphosate determined by physiological responses / Tolerância da soqueira da cana-de-açúcar à erradicação com glyphosate determinada por respostas fisiológicas  

Scientific Electronic Library Online (English)

Full Text Available O presente trabalho teve como objetivo avaliar a tolerância de cultivares de cana-de-açúcar à erradicação de soqueiras com diferentes doses de glyphosate por meio de respostas fisiológicas. Para isso, um ensaio foi desenvolvido no delineamento experimental de blocos ao acaso em esquema fatorial 4 x [...] 4 (cultivares x doses), totalizando 16 tratamentos com quatro repetições. Foram utilizados os cultivares IAC91-5155, IACSP93-3046, IAC86-2480 e IAC87-3396 tratados com as doses de glyphosate 0, 1.920, 2.400, e 2.880gha-1. As variáveis analisadas foram porcentagem de perfilhos mortos, eficiência quântica do FSII (Fv/Fm) e índice SPAD. Há diferenças entre cultivares de cana-de-açúcar quanto à eliminação de perfilhos e a respostas fisiológicas a diferentes doses de glyphosate. A dose de 2.880gha-1 foi a mais eficiente em eliminar perfilhos de cana-de-açúcar. Os cultivares IAC86-2480, IAC87-3396 e IACSP93-3046 foram os mais sensíveis, e o IAC91-5155 tolerou por mais tempo os danos promovidos no aparato fotossintético à dessecação das soqueiras pelo glyphosate. Devido às respostas diferenciadas, manejos distintos devem ser considerados para a eliminação das soqueiras de diferentes cultivares. Abstract in english This study aimed to evaluate the tolerance of sugarcane cultivars to ratoon eradication under different glyphosate rates by means of physiological responses. Therefore, a trial was carried out in randomized complete blocks with 4 x 4 factorial design (cultivars x rates) totaling 16 treatments with f [...] our replicates. The cultivars IAC91-5155, IACSP93-3046, and IAC86-2480 and IAC87-3396 and the glyphosate rates 0 g ha-1; 1,920 g ha-1; 2,400 g ha-1; 2,880 g ha-1 were tested. The variables analyzed were percentage of tiller mortality, quantum efficiency of PSII (Fv/Fm) and SPAD index. The results showed that there are differences among sugarcane cultivars for tiller eradication and for physiological responses with glyphosate different rates. The rate of 2,880 g ha-1 was the most efficient in eliminating sugarcane tillers. The cultivars IAC86-2480, IAC87-3396 and IACSP93-3046 were the most sensitive and the IAC91-5155 tolerated, for a longer period of time, the damage to the photosynthetic apparatus of the ratoons caused by glyphosate desiccation. Due to different responses, different managements should be considered for eliminating ratoons of different cultivars.

M.A., Silva; M.T., Arantes; R., Oliver; M.C., Brunelli.

2014-03-01

143

ADSORPTION OF GLYPHOSATE AND AMPAIN AGRICULTURAL SOILS  

Directory of Open Access Journals (Sweden)

Full Text Available Immediately after application glyphosate is mostly adsorbed in the upper 2 cm of soils, and is then transported and adsorbed after few days in deeper soil horizons with concomitant increasing content of its metabolite aminomethylphosphonic acid (AMPA. This work confirmed previous studies, where Fe-oxides seem to play a major role in the adsorption of glyphosate and AMPA in soils:  the Chernozem featured lower contents of Fed and Feo, with consequently lower adsorption of glyphosate and AMPAas compared with the higher weathered Cambisol and Stagnosol.

Nicola Rampazzo

2013-09-01

144

Monitoring glyphosate and AMPA concentrations in wells and drains using the sorbicell passive sampler  

DEFF Research Database (Denmark)

Glyphosate is one of the world’s most extensively used weed control agents. Glyphosate, and its metabolite aminomethylphosphonic acid (AMPA), are suspected to be hazardous to human health and the aquatic environment. In Denmark, the extensive use has resulted in an increasing number of occurrences in groundwater wells and tile drains, stressing the need for extensive monitoring of this compound in the environment. Traditionally, monitoring programs are based on grab sampling which is time consuming and expensive due to the need for frequent sampling events. Using a passive sampling device, the SorbiCell, will decrease the workload and number of samples freeing up funds for larger monitoring programs. When installed in a well the SorbiCell will continuously sample the water giving either a flux-weighed or time-weighted average measurement of the glyphosate/AMPA concentration throughout the sampling period. It may therefore be possible to measure lower concentrations as the glyphosate/AMPA sorbed in the SorbiCell is an accumulated measurement. Also, glyphosate/AMPA associated with sudden flush events will be detected by the SorbiCells, while such events may pass between two consecutive grab samples. To document the ability of the SorbiCell to capture glyphosate/AMPA, a series of laboratory flow experiments were carried out. Sorption and release from the flow cells is tested with two influent solutions (0.15 µg/l and 5 µg/l), one of demineralized water and the other with drain water from the Silstrup site (part of the Danish Pesticide Leaching Assessment Program, PLAP), spiked with 14C marked glyphosate. Two different volumes of effluent were then eluted through Sorbicell’s with two different capacities. The concentration of glyphosate/AMPA was continuously measured in both the influent and effluent. The aim of the study is to test and verify if the glyphosate/AMPA sensitive SorbiCell is an efficient and reliable, and cost-effective technology for groundwater and drainwater monitoring of pesticides.

Vendelboe, Anders Lindblad; de Jonge, Hubert

145

Associações entre o herbicida glyphosate e inseticidas na cultura da soja Roundup Ready® / Associations among glyphosate and insecticides in Roundup Ready® soybean  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este trabalho teve o objetivo de avaliar os efeitos da associação do herbicida glyphosate com 10 inseticidas de diferentes grupos químicos sobre a cultura da soja Roundup Ready® (cultivar Monsoy 8585 RR®), o controle de plantas daninhas e o controle da lagarta-da-soja (Anticarsia gemmatalis). O expe [...] rimento foi realizado em lavoura no município de Nova Xavantina - MT, no período de novembro de 2005 a abril de 2006, em solo classificado como Latossolo Vermelho distrófico. O delineamento experimental utilizado foi o de blocos ao acaso, em esquema fatorial 11 x 2, sendo os fatores constituídos por 11 tratamentos inseticidas [lambdacyhalothrin (3,75 g ha-1); permethrin (12,50 g ha-1); methamidophos (300,00 g ha-1); chlorpyriphos (240,00 g ha-1); acephate (150,00 g ha-1); endosulfan (175,00 g ha-1); methomyl (107,50 g ha-1); lufenuron (7,50 g ha-1); triflumuron (14,40 g ha-1); spinosad (24,00 g ha-1); e testemunha sem inseticida], com ou sem a adição (mistura em tanque) de 960 g e.a. ha-1 de glyphosate, formando 22 tratamentos, conduzidos em quatro repetições. Os tratamentos foram aplicados 30 dias depois da emergência da cultura. A mistura do herbicida glyphosate com o inseticida chlorpyriphos causou fitotoxicidade inicial à cultura da soja RR®. O controle das plantas daninhas Chamaesyce hirta, Alternanthera tenella, Euphorbia heterophylla e Cenchrus echinatus não foi afetado pelas misturas de glyphosate com todos os inseticidas avaliados. A adição do glyphosate à calda de aplicação prejudicou a eficiência inicial dos inseticidas methomyl, methamidophos, chlorpyriphos e acephate no controle de Anticarsia gemmatalis, porém incrementou o controle dessa praga quando associado aos inseticidas spinosad, lambdacyhalothrin e lufenuron. A combinação de glyphosate com os inseticidas methamidophos, chlorpyriphos, lufenuron, triflumuron e spinosad proporcionou os maiores níveis de produtividade de grãos da soja RR®. Abstract in english This research aimed to evaluate the effects of the association of the herbicide glyphosate with 10 different insecticides of several chemical groups on Roundup Ready® soybean (Monsoy 8585 RR®), weeds, and on velvetbean caterpillar (Anticarsia gemmatalis). The experiment was carried out under field c [...] onditions at Nova Xavantina-MT, from November 2005 to April 2006 in soil classified as Dystrophic Red Latosol. Trial design was a factorial randomized complete block having 11 insecticide treatments: [lambdacyhalothrin (3,75 g ha-1); permethrin (12,50 g ha-1); methamidophos (300,00 g ha-1); chlorpyriphos (240,00 g ha-1); acephate (150,00 g ha-1); endosulfan (175,00 g ha-1); methomyl (107,50 g ha-1); lufenuron (7,50 g ha-1); triflumuron (14,40 g ha-1); spinosad (24,00 g ha-1); and untreated without insecticide] with and without addiction (tank mixture) of 960 g a.e. ha-1 of glyphosate, totalling 22 treatments. Each treatment had four replications. Treatments were applied 30 days after soybean emergence. Tank mixture of glyphosate and insecticide caused phytotoxicity to soybean. The control of the weeds Chamaesyce hirta, Alternathera tenella, Euphorbia heterophylla and Cenchrus echinatus was not affected by the glyphosate mixture. Tank mixture of glyphosate with the insecticides methomyl, methamidophos, chlorpyriphos and acephate reduced their control of Anticarsia gemmatalis. However, the control performance of the insecticides spinosad, lambdacyhalothrin and lufenuron was increased. The combination of glyphosate with the insecticides methamidophos, chlorpyriphos, lufenuron, triflumuron and spinosad provided the highest soybean yields.

F.A., Petter; S.O., Procópio; A., Cargnelutti Filho; A.L.L., Barroso; L.P., Pacheco; A.F., Bueno.

146

Associações entre o herbicida glyphosate e inseticidas na cultura da soja Roundup Ready® Associations among glyphosate and insecticides in Roundup Ready® soybean  

Directory of Open Access Journals (Sweden)

Full Text Available Este trabalho teve o objetivo de avaliar os efeitos da associação do herbicida glyphosate com 10 inseticidas de diferentes grupos químicos sobre a cultura da soja Roundup Ready® (cultivar Monsoy 8585 RR®, o controle de plantas daninhas e o controle da lagarta-da-soja (Anticarsia gemmatalis. O experimento foi realizado em lavoura no município de Nova Xavantina - MT, no período de novembro de 2005 a abril de 2006, em solo classificado como Latossolo Vermelho distrófico. O delineamento experimental utilizado foi o de blocos ao acaso, em esquema fatorial 11 x 2, sendo os fatores constituídos por 11 tratamentos inseticidas [lambdacyhalothrin (3,75 g ha-1; permethrin (12,50 g ha-1; methamidophos (300,00 g ha-1; chlorpyriphos (240,00 g ha-1; acephate (150,00 g ha-1; endosulfan (175,00 g ha-1; methomyl (107,50 g ha-1; lufenuron (7,50 g ha-1; triflumuron (14,40 g ha-1; spinosad (24,00 g ha-1; e testemunha sem inseticida], com ou sem a adição (mistura em tanque de 960 g e.a. ha-1 de glyphosate, formando 22 tratamentos, conduzidos em quatro repetições. Os tratamentos foram aplicados 30 dias depois da emergência da cultura. A mistura do herbicida glyphosate com o inseticida chlorpyriphos causou fitotoxicidade inicial à cultura da soja RR®. O controle das plantas daninhas Chamaesyce hirta, Alternanthera tenella, Euphorbia heterophylla e Cenchrus echinatus não foi afetado pelas misturas de glyphosate com todos os inseticidas avaliados. A adição do glyphosate à calda de aplicação prejudicou a eficiência inicial dos inseticidas methomyl, methamidophos, chlorpyriphos e acephate no controle de Anticarsia gemmatalis, porém incrementou o controle dessa praga quando associado aos inseticidas spinosad, lambdacyhalothrin e lufenuron. A combinação de glyphosate com os inseticidas methamidophos, chlorpyriphos, lufenuron, triflumuron e spinosad proporcionou os maiores níveis de produtividade de grãos da soja RR®.This research aimed to evaluate the effects of the association of the herbicide glyphosate with 10 different insecticides of several chemical groups on Roundup Ready® soybean (Monsoy 8585 RR®, weeds, and on velvetbean caterpillar (Anticarsia gemmatalis. The experiment was carried out under field conditions at Nova Xavantina-MT, from November 2005 to April 2006 in soil classified as Dystrophic Red Latosol. Trial design was a factorial randomized complete block having 11 insecticide treatments: [lambdacyhalothrin (3,75 g ha-1; permethrin (12,50 g ha-1; methamidophos (300,00 g ha-1; chlorpyriphos (240,00 g ha-1; acephate (150,00 g ha-1; endosulfan (175,00 g ha-1; methomyl (107,50 g ha-1; lufenuron (7,50 g ha-1; triflumuron (14,40 g ha-1; spinosad (24,00 g ha-1; and untreated without insecticide] with and without addiction (tank mixture of 960 g a.e. ha-1 of glyphosate, totalling 22 treatments. Each treatment had four replications. Treatments were applied 30 days after soybean emergence. Tank mixture of glyphosate and insecticide caused phytotoxicity to soybean. The control of the weeds Chamaesyce hirta, Alternathera tenella, Euphorbia heterophylla and Cenchrus echinatus was not affected by the glyphosate mixture. Tank mixture of glyphosate with the insecticides methomyl, methamidophos, chlorpyriphos and acephate reduced their control of Anticarsia gemmatalis. However, the control performance of the insecticides spinosad, lambdacyhalothrin and lufenuron was increased. The combination of glyphosate with the insecticides methamidophos, chlorpyriphos, lufenuron, triflumuron and spinosad provided the highest soybean yields.

F.A. Petter

2007-01-01

147

Adjoint design sensitivity analysis of reduced atomic systems using generalized Langevin equation for lattice structures  

International Nuclear Information System (INIS)

An efficient adjoint design sensitivity analysis method is developed for reduced atomic systems. A reduced atomic system and the adjoint system are constructed in a locally confined region, utilizing generalized Langevin equation (GLE) for periodic lattice structures. Due to the translational symmetry of lattice structures, the size of time history kernel function that accounts for the boundary effects of the reduced atomic systems could be reduced to a single atom’s degrees of freedom. For the problems of highly nonlinear design variables, the finite difference method is impractical for its inefficiency and inaccuracy. However, the adjoint method is very efficient regardless of the number of design variables since one additional time integration is required for the adjoint GLE. Through numerical examples, the derived adjoint sensitivity turns out to be accurate and efficient through the comparison with finite difference sensitivity

148

Effect of soil aeration and phosphate addition on the microbial bioavailability of carbon-14-glyphosate.  

Science.gov (United States)

The adsorption, desorption, degradation, and mineralization of C-glyphosate [-(phosphonomethyl)glycine] were examined in Catlin (a fine-silty, mixed, superactive, mesic Oxyaquic Argiudoll), Flanagan (a fine, smectitic, mesic Aquic Argiudoll), and Drummer (a fine-silty, mixed, superactive, mesic Typic Endoaquoll) soils under oxic and anoxic soil conditions. With the exception of the Drummer soil, soil aeration did not significantly alter the adsorption pattern of C-glyphosate to soils. Herbicide desorption was generally enhanced with anaerobiosis in all the soil types. Anoxic soils demonstrated slower microbial degradation and mineralization kinetics of C-glyphosate than oxic soils in all the soil types studied. Phosphate additions significantly reduced the adsorption of C-glyphosate to soils irrespective of soil aeration and confirmed the well-established competitive adsorption theory. The addition of soil phosphate stimulated degradation only in anoxic soils. The results from this research highlight the importance of soil redox conditions as an important factor affecting the bioavailability and mobility of glyphosate in soils. PMID:25602328

Kanissery, Ramdas G; Welsh, Allana; Sims, Gerald K

2015-01-01

149

Influence of glyphosate on the copper dissolution in phosphate buffer  

Science.gov (United States)

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.

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

2007-01-01

150

Re-evaluation of glyphosate determination in water by liquid chromatography coupled to electrospray tandem mass spectrometry.  

Science.gov (United States)

An analytical method based on on-line solid-phase extraction-liquid chromatography coupled to electrospray tandem mass spectrometry (SPE-LC-ESI-MS/MS) for the determination of glyphosate and aminomethylphosphonic acid (AMPA) residues has been applied to the analysis of water samples within a Round Robin Study. The method had been previously validated in a variety of water samples and it fulfilled all the parameters of precision, accuracy, sensitivity and unequivocal confirmation. The results within the study that we participated were highly satisfactory in all cases with the only exception of glyphosate in groundwater samples, where surprisingly recoveries around 15% were obtained despite the use of isotope-labeled glyphosate as internal standard (I.S.). A slight modification has been introduced in the method, simply consisting of the acidification of sample with hydrochloric acid (HCl) to pH 1. Then, the sample is neutralized and immediately derivatized with 9-fluorenylmethylchloroformate (FMOC) before LC-MS/MS determination. Round Robin Study samples were reanalyzed using this approach, and the recoveries increased up to 98%. A possible explanation might be the slow kinetic interaction between glyphosate and some components of the matrix. These components might act as chelating agents, making glyphosate unavailable for derivatization and therefore for analysis. Several water samples collected at the Mediterranean area of Spain, and previously analyzed and being found to contain glyphosate, were also reanalyzed using this approach, obtaining higher concentrations (between 2 and 14 times) in most of cases. PMID:17046009

Ibáñez, María; Pozo, Oscar J; Sancho, Juan V; López, Francisco J; Hernández, Félix

2006-11-17

151

Glyphosate as a tool to produce shikimic acid in plants / Glyphosate como ferramenta para produzir ácido chiquímico em plantas  

Scientific Electronic Library Online (English)

Full Text Available O fosfato de oseltamivir, ingrediente ativo do antiviral Tamiflu®, é um potente inibidor viral produzido a partir do ácido chiquímico e extraído da semente de Ilicium verum, sua mais importante fonte natural. Tendo como sítio de ação a enzima 5 enolpiruvilchiquimato-3-fosfato sintase (EPSPs), o glyp [...] hosate é o único composto capaz de inibir a sua atividade, com o consequente acúmulo do ácido chiquímico nas plantas. Plantas de milho e soja foram pulverizadas com subdoses de glyphosate (0,0 a 230,4 ge.a.ha-1), determinando-se o teor de ácido chiquímico na massa seca dessas plantas por HPLC aos 3,7 e 10 dias após aplicação. Os resultados mostraram acúmulo de ácido chiquímico na massa seca dessas plantas, com aumento de até 969% no milho e 33.000% na soja, com picos de concentração aos 3 DAT. A praticabilidade industrial do processo de obtenção do ácido chiquímico, aliada às condições edafoclimáticas favoráveis ao plantio de milho e soja em diversos países, favorece o uso de subdoses de glyphosate na biossíntese de ácido chiquímico, com potencial para ser explorado como indutor na produção do fosfato de oseltamivir com baixo impacto ambiental. Abstract in english Oseltamivir phosphate is a potent viral inhibitor produced from shikimic acid extracted from seeds of Ilicium verum, the most important natural source. With the site of action 5-enolpyruvylshikimate-3-phosphate synthase (EPSP), glyphosate is the only compound capable of inhibiting its activity with [...] the consequent accumulation of shikimic acid in plants. Corn and soybean plants were sprayed with reduced rates of glyphosate (0.0 to 230.4 g a.i. ha¹) and shikimic acid content in the dry mass was determined by HPLC 3, 7 and 10 days after application. Results showed shikimic acid accumulation in dry mass with increases of up to 969% in corn and 33,000% on soybeans, with peak concentrations 3 days after treatment (DAT). Industrial feasibility for shikimic acid production, combined with favorable climatic conditions for growing corn and soybean in virtually all over Brazil, favor the use of reduced rates of glyphosate in shikimic acid biosynthesis, with potential for use as an inducer in exploration of alternative sources for production of oseltamivir phosphate with low environmental impact.

M.B., Matallo; S.D.B., Almeida; D.A.S., Franco; A.L., Cerdeira; D.L.P., Gazzeiro.

2014-09-01

152

Suppression of reduced sensitivity of eddy current testing depending on defect orientation  

International Nuclear Information System (INIS)

Stress corrosion cracking (SCC) is generated on material structures in nuclear power plants. An eddy current testing (ECT) is used as a method for inspection techniques of a SCC. However when the eddy current direction is in parallel with defect direction, sensitivity of our ECT drops drown to one-quarter than a perpendicular direction. In order to prevent from this reduced sensitivity, Invert Exciting Method was developed. Adjacent exciter coils, which are located in two lines, are alternately opposite in phase of current. Therefore adjacent eddy currents, which are formed in the surface of metallic specimens, are also alternately opposite in phased of current. Then these eddy currents interfere with each other. Consequently eddy currents are inclined to scan direction. Using inclined eddy currents, the ECT has equal detection sensitivity for both defects parallel and perpendicular to scan direction. On the other hand, sensitivity drops down for defects in the same direction to inclined eddy currents. Then we added the function to inverse the phase for exciter coils in a set of line to the ECT system. Hereby the ECT can form symmetrical inclined eddy currents and prevent from reduced sensitivity. We applied Invert Exciting Method to the ECT system and conducted defect detection tests. As a result, we confirmed that detection sensitivity for both parallel and perpendicular defects are equal and Invert Exciting Method is effective in suppression of reduced sensitivity of the ECT depending on defect orientation. (author)

153

Detection of the onset of glyphosate-induced soybean plant injury through chlorophyll fluorescence signal extraction and measurement  

Science.gov (United States)

In this study, chlorophyll fluorescence (ChlF) was used to detect the onset of soybean plant injury from treatment of glyphosate, the most widely used herbicide. Thirty-six pots of nonglyphosate-resistant soybean were randomly divided into three groups and treated with different doses of glyphosate solutions. The three treatment groups were control (CTRL) group (with no glyphosate treatment), 0.25X group (treated with 0.217 kg.ae/ha solution of glyphosate), and 0.5X group (treated with 0.433 kg.ae/ha solution of glyphosate). Three kinds of fluorescence measurements, steady-state fluorescence spectra, Kautsky effect parameters, and ChlF-related spectral indices were extracted and generated from the measurements in the glyphosate treatment experiment. The mean values of these fluorescence measurements for each of the CTRL group, the 0.25X group, and the 0.5X group were calculated. Glyphosate-induced leaf injury was then analyzed by examining the separability of these mean values at 6, 24, 48, and 72 hours after the treatment (HAT). Results indicate that the peak position of far-red ChlF shows an obvious blue shift for glyphosate-treated soybean, and peak values of steady-state fluorescence spectra for the three groups can be significantly distinguished from each other at 48 HAT and later. Four Kautsky effect parameters, Fv, Fv/Fm, Area, and PI, are parameters sensitive to glyphosate treatment, showing some differences between the CTRL group and treated groups at 24 HAT, and significant differences among the three groups at and beyond 48 HAT. Moreover, ChlF-related spectral indices, R6832/(R675.R690) and R690/R655, are also shown to be useful in detection of the glyphosate injury, though they are less effective than the steady-state fluorescence spectra and the Kautsky effect parameters. Based on the presented results, it can be concluded that glyphosate-induced soybean injury can be detected in a timely manner by the ChlF measurements, and this method has the potential to be further developed into practical use.

Zhao, Feng; Guo, Yiqing; Huang, Yanbo; Reddy, Krishna N.; Zhao, Yanhua; Molin, William T.

2015-01-01

154

A 3D scaffold for ultra-sensitive reduced graphene oxide gas sensors  

Science.gov (United States)

An ultra-sensitive gas sensor based on a reduced graphene oxide nanofiber mat was successfully fabricated using a combination of an electrospinning method and graphene oxide wrapping through an electrostatic self-assembly, followed by a low-temperature chemical reduction. The sensor showed excellent sensitivity to NO2 gas.An ultra-sensitive gas sensor based on a reduced graphene oxide nanofiber mat was successfully fabricated using a combination of an electrospinning method and graphene oxide wrapping through an electrostatic self-assembly, followed by a low-temperature chemical reduction. The sensor showed excellent sensitivity to NO2 gas. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00332b

Yun, Yong Ju; Hong, Won G.; Choi, Nak-Jin; Park, Hyung Ju; Moon, Seung Eon; Kim, Byung Hoon; Song, Ki-Bong; Jun, Yongseok; Lee, Hyung-Kun

2014-05-01

155

Methods of reducing X-rays background in super sensitive mini-cyclotron accelerator mass spectrometer  

International Nuclear Information System (INIS)

Through theoretical analysis and careful experiments, the origin of X-ray background in the mini-cyclotron was deduced and some methods to suppress it were described. As a result, the background counts have been reduced to 2/5 of the original value, which has greatly improved the detection efficiency, measurement precision and abundance sensitivity of the sensitive mini-cyclotron accelerator mass spectrometer

156

Histamine Reduces Flash Sensitivity of ON Ganglion Cells in the Primate Retina  

OpenAIRE

The retinas of primates, including humans, receive input from the brain via histaminergic axons emerging from the optic nerve. Exogenously applied histamine selectively reduces the sensitivity of ON-responding retinal ganglion cells. The significance of these findings is that central brain input to the retina, carried by the retinopetal axons of posterior hypothalamic neurons, serves to lower the sensitivity of the retina during the day, when the release of histamine is expected to be the hig...

Akimov, Nikolay P.; Marshak, David W.; Frishman, Laura J.; Glickman, Randolph D.; Yusupov, Rafail G.

2010-01-01

157

Alteração das características biológicas dos biótipos de azevém (Lolium multiflorum ocasionada pela resistência ao herbicida glyphosate Change in the biological characteristics of ryegrass (Lolium multiflorum biotypes caused by resistance to the herbicide glyphosate  

Directory of Open Access Journals (Sweden)

Full Text Available A resistência de biótipos de azevém ao herbicida glyphosate está alterando o manejo da vegetação de cobertura do solo em pomares de maçã. O objetivo deste trabalho foi determinar a dose de glyphosate necessária para reduzir 50% do acúmulo de matéria seca (GR50, a resposta do biótipo resistente e sensível a herbicidas graminicidas e o acúmulo de matéria seca destes biótipos durante o ciclo. Para isso, foram conduzidos três experimentos. No primeiro, os tratamentos constaram de doses crescentes de glyphosate aplicadas sobre plantas dos biótipos resistente e sensível para determinar o GR50. No segundo experimento, os tratamentos constaram de doses dos herbicidas glyphosate, haloxyfop-r, diclofop, fluazifop-p, fenoxaprop-p e paraquat. No terceiro experimento, sementes dos biótipos resistente e sensível foram semeadas em recipientes com capacidade para 10 L e as plantas originadas delas foram colhidas quinzenalmente, para determinação da matéria seca da parte aérea, radicular e total. Como resultados, foi obtido GR50 de 287,5 e de 4.833,5 g e.a. ha-1 de glyphosate para os biótipos sensível e resistente, respectivamente, e verificou-se que existem diferenças significativas na resposta dos biótipos aos herbicidas graminicidas, dependendo da dose utilizada. Além disso, o biótipo sensível evidenciou maior capacidade de acúmulo de matéria seca e produção de sementes. Constatouse, assim, fator de resistência (FR de 16,8 e que o mecanismo de resistência provoca alterações nas características biológicas do biótipo resistente e afeta a sensibilidade deste aos herbicidas graminicidas.The identification of ryegrass biotypes resistant to glyphosate is causing changes in weed management in apple orchards. Three experiments were carried out to determine the GR50 of the biotypes, to grass herbicides and dry matter accumulation. The first experiment tested different rates of glyphosate. Their effects on GR50 dry matter accumulation by the biotype were assessed. In the second experiment different rates of glyphosate and grass herbicides were tested: glyphosate, haloxyfop-r, diclofop, fluazifop-p, fenoxaprop-p and paraquat. A third experiments was carried out under glasshouse conditions to determine the curve of dry matter accumulation. The results showed GR50 of 287.5 and 4,833.5 g e. a. ha-1 of glyphosate for the sensitive and resistant biotypes, respectively. The results showed that the resistant factor (RF was 16.8 and that the resistance mechanism alters the biological characteristics of the resistant biotype affecting its sensitivity to grass herbicides.

L. Vargas

2005-03-01

158

Effect of glyphosate application timings and methods on glyphosate-resistant cotton  

Science.gov (United States)

Under certain conditions, application of glyphosate to glyphosate-resistant (GR) cotton can lead to fruit shedding and yield reductions. Field studies were conducted at the Texas Agricultural Experiment Station using GR cotton, cv. ‘DeltaPine 5690RR’, to determine if application method and timing af...

159

Effect of Glyphosate on Symbiotic N2 Fixation and Nickel Concentration in Glyphosate-Resistant Soybean  

Science.gov (United States)

The impact of widespread cultivation of glyphosate-resistant (GR) soybean and the use of one herbicide class on biological processes has received considerable attention. Decreased biological nitrogen fixation in GR soybean has been attributed directly to toxicity of glyphosate or its metabolites to ...

160

SUSCEPTIBILITY TO GLYPHOSATE OF WEED ESCAPES IN GLYPHOSATE-TOLERANT SOYBEAN  

Science.gov (United States)

Plots of glyphosate-tolerant soybeans at twelve locations in five states were monitored for weed escapes. Seeds were collected from each of these sites in the glyphosate and non-treated weedy check plots. These seeds were planted and grown in a greenhouse and then sprayed one time with 10% of a stan...

161

Differential response of two sourgrass populations to glyphosate  

OpenAIRE

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 ...

Sa?o Paulo State University, Jaboticabal; Bruna Pires da Silva; Paulo Roberto Fidelis Giancotti; Leonardo Bianco de Carvalho; Pedro Luis da Costa Aguiar Alves

2013-01-01

162

What have the mechanisms of resistance to glyphosate taught us?  

Science.gov (United States)

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...

163

Glyphosate translocation in herbicide tolerant plants / Translocação do glyphosate em plantas tolerantes ao herbicida  

Scientific Electronic Library Online (English)

Full Text Available Objetivou-se neste estudo avaliar a translocação de glyphosate em plantas tolerantes (Ipomoea nil, Tridax procumbens e Spermacoce latifolia) e suscetível (Bidens pilosa) a esse herbicida. As avaliações de absorção e translocação do 14C-glyphosate em I. nil e B. pilosa foram efetuadas às 6, 12, 36 e [...] 72 horas após a aplicação do herbicida (HAT), e em T. procumbens e S. latifolia, às 72 HAT. As plantas foram coletadas e fracionadas em: folha de aplicação, demais folhas, caules e raízes; em T. procumbens e S. latifolia, avaliou-se a presença do produto na inflorescência da planta. Em S. latifolia, aproximadamente 88% do glyphosate permaneceu na folha de aplicação, e pequena quantidade translocou para as raízes. Todavia, em T. procumbens, 75% do herbicida permaneceu na folha que recebeu a aplicação, observando-se maior translocação na inflorescência em relação às raízes. Conclui-se que a menor translocação do glyphosate observada em S. latifolia e T. procumbens pode ser um dos fatores responsáveis pela maior tolerância dessas espécies ao herbicida, ao passo que em I. nil a metabolização, a exsudação radicular ou a compartimentalização podem favorecer a tolerância, já que grande quantidade do produto atingiu as raízes da espécie. Abstract in english The objective of this study was to evaluate glyphosate translocation in glyphosate-tolerant weed species (I. nil, T. procumbens and S. latifolia) compared to glyphosate-susceptible species (B. pilosa). The evaluations of 14C-glyphosate absorption and translocation were performed at 6, 12, 36 and 72 [...] hours after treatment (HAT) in I. nil and B. pilosa, and only at 72 HAT in the species T. procumbens and S. latifolia. The plants were collected and fractionated into application leaf, other leaves, stems, and roots. In S. latifolia, approximately 88% of the glyphosate remained in the application leaf and a small amount was translocated to roots at 72 HAT. However, 75% of the herbicide applied on T. procumbens remained in the leaf that had received the treatment, with greater glyphosate translocation to the floral bud. It was concluded that the smaller amount of glyphosate observed in S. latifolia and T. procumbens may partly account for their higher tolerance to glyphosate. However, I. nil tolerance to glyphosate may be associated with other factors such as metabolization, root exudation or compartmentalization, because a large amount of the herbicide reached the roots of this species.

L, Galon; E.A, Ferreira; I, Aspiazú; G, Concenço; A.F, Silva; A.A, Silva; L, Vargas.

2013-03-01

164

Glyphosate Effects on Sugarcane Metabolism and Growth  

Directory of Open Access Journals (Sweden)

Full Text Available Glyphosate is the most widely used herbicide in the world. In sugarcane, it is used as a herbicide when applied at its field rate, but it is also used as ripener when applied as low doses. However, the effects of glyphosate on plant metabolism and sugarcane growth are not fully understood. This study aimed to evaluate the metabolic changes and the effects on sugarcane plant growth caused by the application of different doses of glyphosate. Sugarcane plants were grown in a greenhouse and subjected to glyphosate applications at doses of 7.2; 18; 36; 72; 180; 360 and 720 g a.e. ha-1. Plants grown without an herbicide application were used as a control. Plants from each treatment were collected at 2, 7, 14, and 21 days after treatment (DAT application to quantify the levels of shikimic acid, quinic acid, shikimate-3-phosphate, glyphosate, ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA, phenylalanine, tyrosine, and tryptophan. Visual evaluations of plant intoxication were performed at the same time as the collection of plants, and the quantification of their shoot dry biomass was performed at 21 DAT. At doses of glyphosate greater than 72 g a.e. ha-1, increases in the levels of shikimic acid, quinic acid, and shikimate-3-phosphate occurred and AMPA was detected in the plants. Initially, glyphosate caused increases in the plant levels of phenylalanine and tyrosine at doses of 72 and 180 g a.e. ha-1, although a decrease in the levels of aromatic amino acids subsequently occurred at and above the doses of 72 or 180 g a.e. ha-1. The doses ranging from 7.2 to 36 g a.e. ha-1 promoted an increase in plant shoot biomass, and doses greater than 72 g a.e. ha-1 caused significant reductions in dry mass.

Caio Antonio Carbonari

2014-11-01

165

Genotoxicity of diuron and glyphosate in oyster spermatozoa and embryos.  

Science.gov (United States)

We investigated the effects of genotoxicant exposure in gametes and embryos to find a possible link between genotoxicity and reproduction/developmental impairment, and explore the impact of chemical genotoxicity on population dynamics. Our study focused on the genotoxic effects of two herbicides on oyster gametes and embryos: glyphosate (both as an active substance and in the Roundup formulation) and diuron. France is Europe's leading consumer of agrochemical substances and as such, contamination of France's coastal waters by pesticides is a major concern. Glyphosate and diuron are among the most frequently detected herbicides in oyster production areas; as oyster is a specie with external reproduction, its gametes and embryos are in direct contact with the surrounding waters and are hence particularly exposed to these potentially dangerous substances. In the course of this study, differences in genotoxic and embryotoxic responses were observed in the various experiments, possibly due to differences in pollutant sensitivity between the tested genitor lots. Glyphosate and Roundup had no effect on oyster development at the concentrations tested, whereas diuron significantly affected embryo-larval development from the lowest tested concentration of 0.05 ?g L?¹, i.e. an environmentally realistic concentration. Diuron may therefore have a significant impact on oyster recruitment rates in the natural environment. Our spermiotoxicity study revealed none of the tested herbicides to be cytotoxic for oyster spermatozoa. However, the alkaline comet assay showed diuron to have a significant genotoxic effect on oyster spermatozoa at concentrations of 0.05 ?g L?¹ upwards. Conversely, no effects due to diuron exposure were observed on sperm mitochondrial function or acrosomal membrane integrity. Although our initial results showed no negative effect on sperm function, the possible impact on fertilization rate and the consequences of the transmission of damaged DNA for oyster development and physiological performances, requires further investigation. A likely hypothesis to explain the embryotoxic and genotoxic effects of diuron is that it may act via causing oxidative stress. PMID:22115909

Akcha, F; Spagnol, C; Rouxel, J

2012-01-15

166

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

Science.gov (United States)

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 aminomethylphosphonic acid (AMPA) is the underlying mechanism ...

167

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)

Full Text Available Objetivou-se com este trabalho avaliar a eficiência fotossintética e o uso da água por plantas de clones de eucalipto submetidas ao herbicida glyphosate. O experimento foi realizado em esquema fatorial 4 x 5, com quatro clones de eucalipto (57, 386, 1203 e 1213 e quatro doses de glyphosate (43,2; 86,2; 129,6; e 172,8 g ha-1 e uma testemunha sem herbicida, considerada dose zero, com quatro repetições. Aos 7, 14, 21 e 28 dias após aplicação do herbicida (DAA foi avaliada a intoxicação das plantas, e aos 7 e 21 DAA, o fluxo de gases pelos estômatos (U - mmol s-1, a atividade fotossintética (A - mmol m-2 s-1, a condutância estomática (Gs - mol m-1 s-1, a transpiração (E - mol H2O m-2 s-1 e a eficiência do uso da água (QUE - mol CO2 mol H2O-1. Aos 50 DAA, as plantas de eucalipto foram coletadas e colocadas em estufa de ventilação forçada a 70 ºC até atingirem massa constante. Aos 21 DAA, o clone 1203 comportou-se como mais sensível ao herbicida. Não houve diferença entre clones para as variáveis fisiológicas avaliadas. Aos 21 DAA constatou-se que, com o incremento da dose de glyphosate, houve redução na condutância estomática, na taxa de fluxo de gases pelos estômatos, na taxa fotossintética e na eficiência do uso da água. Plantas dos clones 1213 e 1203 apresentaram maior acúmulo de massa seca. O aumento da dose do glyphosate promoveu menor acúmulo de massa seca das plantas de eucalipto. O glyphosate afetou negativamente o crescimento e a eficiência fotossintética e de uso da água dos clones estudados.The objective of this study was to assess the photosynthetic efficiency and water use by eucalyptus clones submitted to the herbicide glyphosate. The experiment was performed in a 4 x 5 factorial, with four eucalyptus clones (57, 386, 1203 and 1213, four doses of glyphosate (43.2, 86.2, 129.6 and 172.8 g ha-1 and a control without herbicide, considered zero dose, with four replications. At 7, 14, 21 and 28 days 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.

A.F.L. Machado

2010-06-01

168

Growth and Yield of Glyphosate-Resistant Corn under Different Timing of Glyphosate Application  

OpenAIRE

A field experiment was conducted in 2002 in Langkat, North Sumatra, to determine the effects of glyphosate application timing on the growth and grain yield of glyphosate-resistant corn. Glyphosate at 1,500 g ha-1 was applied at twelve different treatments namely at the V3 stage, the V4 stage, the V5 stage, the V6 stage, the V7 stage, the V8 stage, the V9 stage, the V10 stage, the V12 stage, the V3 stage followed by at the V7 stage, the V3 stage followed by at V12 stage and the V4 stage...

Desmarwansyah, N.; Purba, E.

2008-01-01

169

Alteração das características biológicas dos biótipos de azevém (Lolium multiflorum) ocasionada pela resistência ao herbicida glyphosate / Change in the biological characteristics of ryegrass (Lolium multiflorum) biotypes caused by resistance to the herbicide glyphosate  

Scientific Electronic Library Online (English)

Full Text Available A resistência de biótipos de azevém ao herbicida glyphosate está alterando o manejo da vegetação de cobertura do solo em pomares de maçã. O objetivo deste trabalho foi determinar a dose de glyphosate necessária para reduzir 50% do acúmulo de matéria seca (GR50), a resposta do biótipo resistente e se [...] nsível a herbicidas graminicidas e o acúmulo de matéria seca destes biótipos durante o ciclo. Para isso, foram conduzidos três experimentos. No primeiro, os tratamentos constaram de doses crescentes de glyphosate aplicadas sobre plantas dos biótipos resistente e sensível para determinar o GR50. No segundo experimento, os tratamentos constaram de doses dos herbicidas glyphosate, haloxyfop-r, diclofop, fluazifop-p, fenoxaprop-p e paraquat. No terceiro experimento, sementes dos biótipos resistente e sensível foram semeadas em recipientes com capacidade para 10 L e as plantas originadas delas foram colhidas quinzenalmente, para determinação da matéria seca da parte aérea, radicular e total. Como resultados, foi obtido GR50 de 287,5 e de 4.833,5 g e.a. ha-1 de glyphosate para os biótipos sensível e resistente, respectivamente, e verificou-se que existem diferenças significativas na resposta dos biótipos aos herbicidas graminicidas, dependendo da dose utilizada. Além disso, o biótipo sensível evidenciou maior capacidade de acúmulo de matéria seca e produção de sementes. Constatouse, assim, fator de resistência (FR) de 16,8 e que o mecanismo de resistência provoca alterações nas características biológicas do biótipo resistente e afeta a sensibilidade deste aos herbicidas graminicidas. Abstract in english The identification of ryegrass biotypes resistant to glyphosate is causing changes in weed management in apple orchards. Three experiments were carried out to determine the GR50 of the biotypes, to grass herbicides and dry matter accumulation. The first experiment tested different rates of glyphosat [...] e. Their effects on GR50 dry matter accumulation by the biotype were assessed. In the second experiment different rates of glyphosate and grass herbicides were tested: glyphosate, haloxyfop-r, diclofop, fluazifop-p, fenoxaprop-p and paraquat. A third experiments was carried out under glasshouse conditions to determine the curve of dry matter accumulation. The results showed GR50 of 287.5 and 4,833.5 g e. a. ha-1 of glyphosate for the sensitive and resistant biotypes, respectively. The results showed that the resistant factor (RF) was 16.8 and that the resistance mechanism alters the biological characteristics of the resistant biotype affecting its sensitivity to grass herbicides.

L., Vargas; E.S., Roman; M.A., Rizzardi; V.C., Silva.

2005-03-01

170

STUDY OF CHRONIC TOXICITY OF THE GLYPHOSATE HERBICIDE IN SEEDS OF CORN,  

Directory of Open Access Journals (Sweden)

Full Text Available Glyphosate is an agrochemical from the group of phosphonates, which is widely used as a herbicide. Although it kills almost any plant, it can be used to eliminate weeds during the growth of crops that are resistant to glyphosate. This research aimed to evaluate the toxicological effects of the herbicide in a study using as test organism seeds of maize (Zea mays, okra (Abelmoschus esculentus (L. Moench and arugula (Eruca sativa. The toxicological testing was to use a paper towel dampened with a sample of glyphosate and twenty seeds evenly distributed in containers with lids, left in a dry and airy place, and watered once a day for 5 days. It was possible to check the toxic effect of glyphosate for corn seeds at concentrations above 90 mg.L-1, for okra seeds at concentrations above 75 mg L-1 and arugula seeds in concentrations above 2 mg L - 1. Thus it was concluded that the seeds studied showed a high sensitivity with the possibility to be applied in toxicity testing, representing a simple and low cost.

Ana Cláudia Rebessi

2011-07-01

171

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

Science.gov (United States)

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. PMID:25625294

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

2015-02-18

172

Post-treatment with plant extracts used in Brazilian folk medicine caused a partial reversal of the antiproliferative effect of glyphosate in the Allium cepa test  

Scientific Electronic Library Online (English)

Full Text Available Species of the genus Psychotria are used for multiple purposes in Brazilian folk medicine, either as water infusions, baths or poultices. This study was aimed to evaluate the genotoxic and antiproliferative effects of infusions of Psychotria brachypoda and P. birotula on the Allium cepa test. Exposu [...] re to distilled water was used as a negative control, while exposure to glyphosate was used as a positive control. The interaction of extracts (as a post-treatment) with the effects of glyphosate was also studied. Results showed that glyphosate and the extracts of both P. brachypoda and P. birotula reduced the mitotic index as compared with the negative control (distilled water). Surprisingly, however, both extracts from P. brachypoda and P. birotula caused a partial reversal of the antiproliferative effect of glyphosate when used as a post-treatment. Glyphosate also induced the highest number of cells with chromosomal alterations, which was followed by that of P. birotula extracts. However, the extracts from P. brachypoda did not show any significant genotoxic effect. Post-treatment of glyphosate-treated samples with distilled water allowed a partial recovery of the genotoxic effect of glyphosate, and some of the Psychotria extracts also did so. Notably, post-treatment of glyphosate-treated samples with P. brachypoda extracts induced a statistically significant apoptotic effect. It is concluded that P. brachypoda extracts show antiproliferative effects and are not genotoxic, while extracts of P. birotula show a less potent antiproliferative effect and may induce chromosomal abnormalities. The finding of a partial reversion of the effects of glyphosate by a post-treatment with extracts from both plants should be followed up.

Viviane, Dal-Souto Frescura; Andrielle, Wouters Kuhn; Haywood Dail, Laughinghouse Iv; Juçara, Terezinha Paranhos; Solange, Bosio Tedesco.

2013-08-01

173

Efeito de concentrações de espalhante adesionante e doses de glyphosate no controle de Brachiaria decumbens e Panicum maximum / Effects of adhesive spreading and glyphosate on Brachiaria decumbens and Panicum maximum control  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Foram avaliadas as interações entre o glyphosate e o espalhante adesionante correspondente ao condensado de alcoolfenóis com óxido de eteno e sulfonados orgânicos quanto à redução de tensão superficial e ao controle de Panicum maximum e Brachiaria decumbens. Os produtos comerciais apresentavam 360 g [...] e.a./l e 466 g i.a./l, respectivamente. O herbicida reduziu o efeito do espalhante sobre a tensão superficial. Na concentração de 0,1% de p.c., o espalhante maximizou o controle das duas espécies pelo glyphosate. P. maximum mostrou-se menos sensível ao glyphosate que B. decumbens, exigindo doses 24,05% superiores. Abstract in english The interactions of glyphosate and one adhesive spreading (concentrate of alcoholphenols with ethene-oxide and organic sulfonates) in reducing the surface tension and controlling Brachiaria decumbens and Panicum maximum were evaluated. It were used comercial products with 360 g a.e/l and 466 g i.a./ [...] l, respectivelly. To achieve similar control levels, the herbicide rates should be 24,05% higher for the second species. The herbicide reduced the effect of the surfactant on surface tension. The concentration of 0,1 % (c.p.) of the surfactant maximized the efficacy of glyphosate in controlling the two grasses.

Edivaldo D., Velini; Dagoberto, Martins; Marco A. de Souza, Silva.

2000-08-01

174

Opposing effects of reduced kidney mass on liver and skeletal muscle insulin sensitivity in obese mice.  

Science.gov (United States)

Reduced kidney mass and/or function may result in multiple metabolic derangements, including insulin resistance. However, underlying mechanisms are poorly understood. Herein, we aimed to determine the impact of reduced kidney mass on glucose metabolism in lean and obese mice. To that end, 7-week-old C57BL/6J mice underwent uninephrectomy (UniNx) or sham operation. After surgery, animals were fed either a chow (standard) diet or a high-fat diet (HFD), and glucose homeostasis was assessed 20 weeks after surgery. Intraperitoneal glucose tolerance was similar in sham-operated and UniNx mice. However, insulin-stimulated glucose disposal in vivo was significantly diminished in UniNx mice, whereas insulin-stimulated glucose uptake into isolated skeletal muscle was similar in sham-operated and UniNx mice. Of note, capillary density was significantly reduced in skeletal muscle of HFD-fed UniNx mice. In contrast, hepatic insulin sensitivity was improved in UniNx mice. Furthermore, adipose tissue hypoxia-inducible factor 1? expression and inflammation were reduced in HFD-fed UniNx mice. Treatment with the angiotensin II receptor blocker telmisartan improved glucose tolerance and hepatic insulin sensitivity in HFD-fed sham-operated but not UniNx mice. In conclusion, UniNx protects from obesity-induced adipose tissue inflammation and hepatic insulin resistance, but it reduces muscle capillary density and, thus, deteriorates HFD-induced skeletal muscle glucose disposal. PMID:25325737

Chin, Siew Hung; Item, Flurin; Wueest, Stephan; Zhou, Zhou; Wiedemann, Michael S F; Gai, Zhibo; Schoenle, Eugen J; Kullak-Ublick, Gerd A; Al-Hasani, Hadi; Konrad, Daniel

2015-04-01

175

Fuzzy Controller Based Dvr To Mitigate Power Quaity And Reduce The Harmonics Distortion Of Sensitive Load  

OpenAIRE

PI controller is very common in the control of DVRs. However, one disadvantage of this conventional controller is its inability to still working well under a wider range of operating conditions. So, as a solution fuzzy controller is proposed. This paper discusses the design and simulation of dynamic voltage restorer for improve power quality and reduce the harmonics distortion of sensitive load. Power quality problem is an occur as a non-standard voltage, current and frequency. Electronics de...

SANDESH JAIN; PROF.SHIVENDRA SINGH THAKUR; Phulambrikar, Prof S. P.

2013-01-01

176

Leaching of glyphosate and AMPA under two soil management practices in Burgundy vineyards (Vosne-Romanee, 21-France)  

Energy Technology Data Exchange (ETDEWEB)

Some drinking water reservoirs under the vineyards of Burgundy are contaminated with herbicides. Thus the effectiveness of alternative soil management practices, such as grass cover, for reducing the leaching of glyphosate and its metabolite, AMPA, through soils was studied. The leaching of both molecules was studied in structured soil columns under outdoor conditions for 1 year. The soil was managed under two vineyard soil practices: a chemically treated bare calcosol, and a vegetated calcosol. After 680 mm of rainfall, the vegetated calcosol leachates contained lower amounts of glyphosate and AMPA (0.02% and 0.03%, respectively) than the bare calcosol leachates (0.06% and 0.15%, respectively). No glyphosate and only low amounts of AMPA (<0.01%) were extracted from the soil. Glyphosate, and to a greater extent, AMPA, leach through the soils; thus, both molecules may be potential contaminants of groundwater. However, the alternative soil management practice of grass cover could reduce groundwater contamination by the pesticide. - Glyphosate and AMPA leached in greater amounts through a chemically treated bare calcosol than through a vegetated calcosol.

Landry, David [UMR 1229 INRA/Universite de Bourgogne, Microbiologie et Geochimie des sols, Centre des Sciences de la Terre, Universite de Bourgogne, 6 bd Gabriel 21000 Dijon (France)]. E-mail: david.landry@u-bourgogne.fr; Dousset, Sylvie [UMR 1229 INRA/Universite de Bourgogne, Microbiologie et Geochimie des sols, Centre des Sciences de la Terre, Universite de Bourgogne, 6 bd Gabriel 21000 Dijon (France); Fournier, Jean-Claude [UMR 1229 INRA/Universite de Bourgogne, INRA, 17 rue Sully, 21000 Dijon (France); Andreux, Francis [UMR 1229 INRA/Universite de Bourgogne, Microbiologie et Geochimie des sols, Centre des Sciences de la Terre, Universite de Bourgogne, 6 bd Gabriel 21000 Dijon (France)

2005-11-15

177

Leaching of glyphosate and AMPA under two soil management practices in Burgundy vineyards (Vosne-Romanee, 21-France)  

International Nuclear Information System (INIS)

Some drinking water reservoirs under the vineyards of Burgundy are contaminated with herbicides. Thus the effectiveness of alternative soil management practices, such as grass cover, for reducing the leaching of glyphosate and its metabolite, AMPA, through soils was studied. The leaching of both molecules was studied in structured soil columns under outdoor conditions for 1 year. The soil was managed under two vineyard soil practices: a chemically treated bare calcosol, and a vegetated calcosol. After 680 mm of rainfall, the vegetated calcosol leachates contained lower amounts of glyphosate and AMPA (0.02% and 0.03%, respectively) than the bare calcosol leachates (0.06% and 0.15%, respectively). No glyphosate and only low amounts of AMPA (<0.01%) were extracted from the soil. Glyphosate, and to a greater extent, AMPA, leach through the soils; thus, both molecules may be potential contaminants of groundwater. However, the alternative soil management practice of grass cover could reduce groundwater contamination by the pesticide. - Glyphosate and AMPA leached in greater amounts through a chemically treated bare calcosol than through a vegetated calcosol

178

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O amarelecimento da soja Roundup Ready após aplicação do glyphosate pode estar associado à deficiência momentânea de manganês. Por isso, com a hipótese de que soja tolerante ao glyphosate necessitaria de uma adição suplementar de manganês, o objetivo deste trabalho foi avaliar diferentes manejos na [...] aplicação foliar de manganês sobre alguns parâmetros da soja. Foram desenvolvidos dois experimentos, um no município de Taquaruçú do Sul e outro em Boa Vista das Missões, RS, no ano agrícola 2009/2010. Foram testados os seguintes tratamentos: 1) sem aplicação de glyphosate, com controle manual das plantas daninhas e sem aplicação foliar de manganês (testemunha); 2) sem aplicação de glyphosate, com controle manual das plantas daninhas e uma aplicação foliar de manganês sete dias após esse controle manual das plantas daninhas; 3) com aplicação de glyphosate e sem aplicação foliar de manganês; 4) aplicação de glyphosate em mistura com manganês; 5) aplicação de glyphosate mais uma aplicação foliar de manganês sete dias após aplicação do glyphosate; 6) aplicação de glyphosate mais aplicação foliar de manganês parcelada em duas épocas, aos 7 e 14 dias após aplicação do glyphosate; 7) aplicação de glyphosate e uma aplicação foliar de manganês aos 14 dias após aplicação de glyphosate. A aplicação de glyphosate foi realizada no estádio V5 da soja, na dose de 720g L-1 e.a, enquanto a dose de Mn utilizada foi 2,0L ha-1 de uma formulação contendo 14% (m/v) de manganês solúvel. Não houve diferença significativa entre os tratamentos para as variáveis estatura de plantas e altura de inserção da primeira vagem. A aplicação de glyphosate não afetou a absorção e o teor foliar de manganês e nitrogênio na cultura da soja. Mesmo com aumento no teor foliar de manganês com a suplementação de manganês, não houve incremento na produtividade da soja. Isso mostra que em solos com teores de Mn acima do suficiente a aplicação do herbicida glifosato não requer a suplementação foliar de manganês em soja geneticamente modificada tolerante a esse herbicida. Abstract in english 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 m [...] anagements 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 suffic

Claudir José, Basso; Antônio Luis, Santi; Fabiane Pinto, Lamego; Eduardo, Girotto.

1726-17-01

179

AUXIN-PRODUCING BACTERIA AND UREASE ACTIVITY IN THE RHIZOSPHERE OF GLYPHOSATE-RESISTANT SOYBEAN  

Science.gov (United States)

Repeated use of glyphosate on glyphosate-resistant crops has raised concerns regarding the potential environmental impacts of this herbicide. Glyphosate may affect microbial production of plant-growth-regulating compounds including hydrogen cyanide, phytohormones including auxins, and other unidenti...

180

Suscetibilidade de genótipos de Lolium multiflorum ao herbicida glyphosate Susceptibility of Lolium multiflorum genotypes to glyphosate  

OpenAIRE

Objetivou-se com este trabalho avaliar o grau de tolerância dos genótipos diploides e tetraploides de L. multiflorum (azevém) ao herbicida glyphosate. Para isso, foram instalados quatro experimentos, sendo um para cada estádio fenológico do azevém (duas folhas, quatro perfilhos, pré-florescimento e formação de grãos). Utilizou-se delineamento em blocos casualizados com arranjo fatorial 2 x 6 (dois genótipos e seis doses do herbicida glyphosate: 240, 480, 960, 1.920, 3.840 e 7.680 g...

Dors, C. A.; Christoffoleti, P. J.; Sanchotene, D. M.; Dias, A. C. R.; Manfron, P. A.; Dornelles, S. H. B.

2010-01-01

181

Simplified analysis of glyphosate and aminomethylphosphonic acid in water, vegetation, and soil by liquid chromatography-tandem mass spectrometry  

Science.gov (United States)

A simple, fast, efficient, and sensitive method was developed for analysis of glyphosate and its degradate, aminomethylphosphonic acid (AMPA), in water, vegetation, and soil. Aqueous extracts were passed through reverse phase and cation exchange columns and directly injected into a tandem mass spect...

182

Effect of Reducing Groundwater on the Retardation of Redox-Sensitive Radionuclides  

Energy Technology Data Exchange (ETDEWEB)

Laboratory batch sorption experiments were used to investigate variations in the retardation behavior of redox-sensitive radionuclides. Water-rock compositions used during these experiments were designed to simulate subsurface conditions at the Nevada Test Site (NTS), where a suite of radionuclides were deposited as a result of underground nuclear testing. Experimental redox conditions were controlled by varying the oxygen content inside an enclosed glove box and by adding reductants into the testing solutions. Under atmospheric (oxidizing) conditions, the radionuclide distribution coefficients varied with the mineralogical composition of the sorbent and the water chemistry. Under reducing conditions, distribution coefficients showed marked increases for {sup 99}Tc and {sup 237}Np in devitrified tuff, but much smaller variations in alluvium, carbonate rock, and zeolitic tuff. This effect was particularly important for {sup 99}Tc, which tends to be mobile under oxidizing conditions. Unlike other redox-sensitive radionuclides, iodine sorption may decrease under reducing conditions when I{sup -} is the predominant species. Overall, sorption of U to alluvium, devitrified tuff, and zeolitic tuff under atmospheric conditions was less than in the glove-box tests. However, the mildly reducing conditions achieved here were not likely to result in substantial U(VI) reduction to U(IV). Sorption of Pu was not affected by the decreasing redox conditions achieved in this study, as the predominant sorbed Pu species in all conditions was expected to be the low-solubility and strongly sorbing Pu(OH){sub 4}. Depending on the aquifer lithology, the occurrence of reducing conditions along a groundwater flowpath could potentially contribute to the retardation of redox-sensitive radionuclides {sup 99}Tc and {sup 237}Np, which are commonly identified as long-term dose contributors in the risk assessment in various nuclear facilities.

Hu, Q; Zavarin, M; Rose, T P

2008-04-21

183

Influence of late emerging weeds in glyphosate-resistant corn  

Directory of Open Access Journals (Sweden)

Full Text Available Fifteen field trials were conducted from 2009 to 2011 in Ontario, Canada and Michigan, USA to determine how long glyphosate-resistant corn needs to be kept weed-free after emergence to prevent yield loss. Data were separated into two environments based on when yield loss first occurred after glyphosate application. In Environment 1 (4/15 sites yield was not reduced when corn was kept weed-free until the 4-leaf stage. However, in Environment 2 (11/15 sites there was no yield loss when corn was kept weed-free up to the 2-leaf stage. The most prominent weeds were velvetleaf, redroot pigweed, common ragweed, common lambsquarters and foxtail species. While later emerging weeds did not necessarily impact corn yield, weeds emerging after the 2- and 4-leaf corn stage likely produced seed that was added to the soil seed bank. Weeds emerging after 6-, 8-, and 10-leaf corn growth stages were small (low biomass/seedlings and most likely did not reach reproductive maturity. Based on this research, corn must be maintained weed-free up to the 4-leaf stage. Any weeds emerging after that did not influence corn yield.

Nader Soltani

2013-06-01

184

Características fisiológicas de biótipos de Conyza bonariensis Resistentes ao glyphosate cultivados sob competição / Physiological characteristics of Conyza bonariensis biotypes resistant to glyphosate cultivated under competition  

Scientific Electronic Library Online (English)

Full Text Available A resistência de plantas daninhas a herbicidas está relacionada a modificações metabólicas, enzimáticas, fisiológicas e/ou anatômicas. Aliado a essas mudanças, a planta pode aumentar ou diminuir as atividades fisiológicas, o que, consequentemente, pode afetar o seu crescimento e desenvolvimento. Ass [...] im, biótipos resistentes podem apresentar melhor adaptação ecológica em ambientes de cultivo e tornar-se predominantes devido à eliminação das plantas sensíveis. Em condições de seleção natural, biótipos com maior adaptação ecológica apresentam maior produção que biótipos menos adaptados. Neste trabalho, avaliou-se o efeito da competição em características fisiológicas de biótipos de Conyza bonariensis suscetíveis e resistentes ao herbicida glyphosate. Os tratamentos constaram de plantas de dois biótipos de C. bonariensis - um comprovadamente resistente e um suscetível ao glyphosate, dispostas em modelo aditivo de estudo de competição. No centro da unidade experimental foram semeadas três sementes do biótipo considerado como o tratamento: resistente (R) ou suscetível (S), sendo essa planta rodeada por 0 (testemunha sem competição), 1, 2, 3, 4, ou 5 plantas do biótipo oposto. O biótipo suscetível apresentou-se mais tolerante à competição com plantas do biótipo oposto no tocante às características fisiológicas avaliadas. O biótipo resistente de buva apresenta desvantagem fisiológica em relação ao suscetível e, consequentemente, menor potencial de adaptabilidade na ausência do fator de seleção - o herbicida glyphosate. Abstract in english The resistance of weeds to herbicides is related to metabolic, enzymatic, physiological and anatomical changes. Coupled with these changes, plants can increase or decrease their physiological activities, which can affect their growth and development. Thus, resistant biotypes may have a higher ecolog [...] ical adaptation in these environments and become predominant due to the elimination of sensitive plants. Under natural selection conditions, biotypes with greater ecological adaptation show higher production than less adapted biotypes. Thus, the aim of this work was to assess the effect of competition on the physiological characteristics of Conyza bonariensis biotypes susceptible and resistant to the herbicide glyphosate. The treatments consisted of plants of two biotypes of C. bonariensis - one proven to be resistant and one susceptible to glyphosate. In the center of the experimental unit, three seeds of the C. bonariensis biotype considered for treatment - resistant (R) or susceptible (S) - were sown , with the plant being surrounded by 0 (no competition), 1, 2, 3, 4, or 5 plants of the opposite biotype. The susceptible biotype presented a higher tolerance to competition with plants of the opposite biotype regarding the physiological characteristics evaluated. The resistant biotype of C. bonariensis has a physiological disadvantage compared to the susceptible one and, therefore, less potential for adaptability in the absence of the selection factor - the herbicide glyphosate.

L., Galon; E.A., Ferreira; G., Concenço; A.A., Silva; D.V., Silva; A.F., Silva; I, Aspiazú; L., Vargas.

2013-12-01

185

[Glyphosate-resistant cotton (Gossypium hirsutum L.) Transformed with aroAM12 gene via Agrobacterium tumefaciens].  

Science.gov (United States)

A mutant, aroAM12, exhibiting resistance to glyphosate produced in a previous study using the staggered extension process with aroA genes from Salmonella typhimurium and Eschrichia coli. In this paper, we constructed a vector pGRA1300 carrying aroAM12 gene, comprising transit peptide of Arabidopsis EPSPS, under the control of the CaMV35S promoter and used as selectable marker for cotton plant (Gossypium hirsutum L.) transformation. Transgenic cottons with increased resistance to glyphosate were obtained by cotransformtion of hypocotyl segments with Agrobacterium tumefaciens and selected directly on medium containing glyphosate. Regeneration of glyphosate-resistant calli was carried out on a MS basic medium containing 2,4-D 0.1 mg/L, KT 0.1 mg/L, cefotaxime 500 mg/L and glyphosate 60 micromol/L. Globular embryos were induced and then developed by culturing on MSB (MS salts+B(5) vitamins) medium supplemented with asparagine 1 g/L and glutamine 2 g/L, but not containing hormone, for 40 d. The developed plantlets were then removed and cultured on an MS medium. After about 20 d, the deeply-rooted shoots were in soil. PCR analysis showed that the aroAM12 gene was present in all T(0) transgenic plants. The integration of the aroAM12 gene in the genomic DNA of cotton was further confirmed by Southern blot, which showed that the transgenic plants carried one or two copies of the aroAM12 genes. Western blot analysis showed that a 48-kD band of was detected in all T(0) transgenic plants. There was no apparent corelation between copy numbers and the expression level of the aroAM12 gene. Greenhouse screening for glyphosate resistance was performed to test 65 independent T(0) plants by spraying (three times) with an aqueous suspension at a dose corresponding to 9.317 kg/ha of Roundup (once every 5 d). After 15 d, phenotype examination was carried out of the plants in comparison with untransformed control plants. Under these conditions, it was observed that the plants transformed with pGRA1300 showed high resistance to glyphosate whereas the control plants were all killed. The glyphosate resistance of T(1) generation was measured by spraying with Roundup, the numbers of glyphosate resistance and sensitive phenotypes showed Mendelian segregation ratio. PMID:15599043

Xie, Long-Xu; Li, Yun-Feng; Xu, Pei-Lin

2004-04-01

186

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

Science.gov (United States)

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. PMID:19672764

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

2009-01-01

187

Praziquantel sensitivity of Kenyan Schistosoma mansoni isolates and the generation of a laboratory strain with reduced susceptibility to the drug  

OpenAIRE

•We isolated S. mansoni miracidia from 72 Kenyan adults and children.•We found no evidence of S. mansoni with reduced praziquantel sensitivity.•An S. mansoni lab isolate with reduced praziquantel sensitivity was established.•The potential for the emergence of praziquantel resistance remains.

Mwangi, Ibrahim N.; Sanchez, Melissa C.; Mkoji, Gerald M.; Agola, Lelo E.; Runo, Steven M.; Cupit, Pauline M.; Cunningham, Charles

2014-01-01

188

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Objetivou-se com este trabalho avaliar os efeitos da deriva de formulações comerciais de glyphosate no desenvolvimento de plantas jovens de maracujazeiro amarelo. O trabalho foi realizado em casa de vegetação do Departamento de Fitotecnia da Universidade Federal de Viçosa, durante o período de março [...] a abril de 2007. Foi utilizado o delineamento experimental de blocos casualizados, em esquema fatorial 3 x 4 + 1, em que três foram as formulações de glyphosate e cinco foram as doses utilizadas acrescidas de testemunha sem herbicida. O trabalho foi conduzido com cinco repetições, sendo cada planta considerada como parcela experimental. As formulações comerciais aplicadas foram Roundup Transorb®, Roundup Original® e Zapp QI®, utilizando-se as seguintes doses (g e.a ha-1): 43,2; 86,4; 172,8; e 345,6 g ha-1. Aos 28 dias após a aplicação (DAA), avaliaram-se os comprimentos da parte aérea, da raiz e total (cm); o diâmetro do caule (mm); o número de folhas e de ramificações primárias; a massa seca da parte aérea e da raiz das plantas (g); e a área foliar por planta (cm²). Aos 7, 14 e 28 DAA, avaliou-se, visualmente, a porcentagem de intoxicação das plantas. O glyphosate em deriva simulada, independentemente das formulações utilizadas, ocasionou injúrias no maracujazeiro amarelo, acarretando redução no crescimento e desenvolvimento das plantas. As formulações Roundup Transorb® e Roundup Original® foram mais prejudiciais às plantas que o Zapp Qi®. O maracujazeiro amarelo mostrou-se suscetível à deriva, devendo o glyphosate ser usado com cuidado, de maneira a atingir somente as plantas daninhas a serem controladas. Abstract in english The aim of this work was to evaluate the effects of drift simulation of commercial formulations of glyphosate on the growth of young plants of yellow passion fruit. The work was carried out at the Plant Science Department of the Universidade Federal de Viçosa (MG), Brazil, from March to April 2007. [...] The 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.

A., Wagner Júnior; L.D., Tuffi Santos; C.E.M., Santos; J.O.C., Silva; L.D., Pimentel; C.H., Bruckner; F.A., Ferreira.

189

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)

Full Text Available Objetivou-se com este trabalho avaliar os efeitos da deriva de formulações comerciais de glyphosate no desenvolvimento de plantas jovens de maracujazeiro amarelo. O trabalho foi realizado em casa de vegetação do Departamento de Fitotecnia da Universidade Federal de Viçosa, durante o período de março a abril de 2007. Foi utilizado o delineamento experimental de blocos casualizados, em esquema fatorial 3 x 4 + 1, em que três foram as formulações de glyphosate e cinco foram as doses utilizadas acrescidas de testemunha sem herbicida. O trabalho foi conduzido com cinco repetições, sendo cada planta considerada como parcela experimental. As formulações comerciais aplicadas foram Roundup Transorb®, Roundup Original® e Zapp QI®, utilizando-se as seguintes doses (g e.a ha-1: 43,2; 86,4; 172,8; e 345,6 g ha-1. Aos 28 dias após a aplicação (DAA, avaliaram-se os comprimentos da parte aérea, da raiz e total (cm; o diâmetro do caule (mm; o número de folhas e de ramificações primárias; a massa seca da parte aérea e da raiz das plantas (g; e a área foliar por planta (cm². Aos 7, 14 e 28 DAA, avaliou-se, visualmente, a porcentagem de intoxicação das plantas. O glyphosate em deriva simulada, independentemente das formulações utilizadas, ocasionou injúrias no maracujazeiro amarelo, acarretando redução no crescimento e desenvolvimento das plantas. As formulações Roundup Transorb® e Roundup Original® foram mais prejudiciais às plantas que o Zapp Qi®. O maracujazeiro amarelo mostrou-se suscetível à deriva, devendo o glyphosate ser usado com cuidado, de maneira a atingir somente as plantas daninhas a serem controladas.The aim of this work was to evaluate the effects of drift simulation of commercial formulations of glyphosate on the growth of young plants of yellow passion fruit. The work was carried out at the Plant Science Department of the Universidade Federal de Viçosa (MG, Brazil, from March to April 2007. The 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.

A. Wagner Júnior

2008-01-01

190

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 Sã [...] o 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. Abstract in english 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. bonariensis was satisfactory when post-emergence herbicides were used in wheat crop and glyphosate and 2,4-D or glyphosate paraquat diuron in pre-planting soybeans.

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

2011-03-01

191

Photomultiplier circuit including means for rapidly reducing the sensitivity thereof. [and protection from radiation damage  

Science.gov (United States)

A simple, reliable and inexpensive control circuit is described for rapidly reducing the bias voltage across one or more of the dynode stages of a photomultiplier, to substantially decrease its sensitivity to incoming light at those times where excess light intensity might damage the tube. The control circuit comprises a switching device, such as a silicon controlled rectifier (SCR), coupled between a pair of the electrodes in the tube, preferably the cathode and first dynode, or the first and second dynodes, the switching device operating in response to a trigger pulse applied to its gate to short circuit the two electrodes. To insure the desired reduction in sensitivity, two switching stages, the devices be employed between two of the electrode stages, the devices being operated simultaneously to short circuit both stages.

Mcclenahan, J. O. (inventor)

1974-01-01

192

Effects of field-realistic doses of glyphosate on honeybee appetitive behaviour.  

Science.gov (United States)

Glyphosate (GLY) is a broad-spectrum herbicide used for weed control. The sub-lethal impact of GLY on non-target organisms such as insect pollinators has not yet been evaluated. Apis mellifera is the main pollinator in agricultural environments and is a well-known model for behavioural research. Honeybees are also accurate biosensors of environmental pollutants and their appetitive behavioural response is a suitable tool with which to test sub-lethal effects of agrochemicals. We studied the effects of field-realistic doses of GLY on honeybees exposed chronically or acutely to the herbicide. We focused on sucrose sensitivity, elemental and non-elemental associative olfactory conditioning of the proboscis extension response (PER), and foraging-related behaviour. We found a reduced sensitivity to sucrose and learning performance for the groups chronically exposed to GLY concentrations within the range of recommended doses. When olfactory PER conditioning was performed with sucrose reward with the same GLY concentrations (acute exposure), elemental learning and short-term memory retention decreased significantly compared with controls. Non-elemental associative learning was also impaired by an acute exposure to GLY traces. Altogether, these results imply that GLY at concentrations found in agro-ecosystems as a result of standard spraying can reduce sensitivity to nectar reward and impair associative learning in honeybees. However, no effect on foraging-related behaviour was found. Therefore, we speculate that successful forager bees could become a source of constant inflow of nectar with GLY traces that could then be distributed among nestmates, stored in the hive and have long-term negative consequences on colony performance. PMID:25063858

Herbert, Lucila T; Vázquez, Diego E; Arenas, Andrés; Farina, Walter M

2014-10-01

193

Effectiveness of the nitrate sensitive areas scheme in reducing groundwater concentrations in England  

OpenAIRE

The Nitrates Sensitive Areas (NSA) Scheme in England was a voluntary, compensated measure from 1990 to 2003 which aimed to reduce nitrate leaching from agricultural land to vulnerable groundwaters by modifying land use management. Measurements from 22 NSAs introduced in 1994/5 show an overall 34% decrease in the nitrate concentration of water leaching from the soils from 115?mg/l (1994/5-1995/6) to 76?mg/l (1998/9-1999/2000). This study looks at two NSAs in depth. The Old Chalford NSA con...

Silgram, M.; Williams, A.; Waring, R.; Neumann, I.; Hughes, A.; Mansour, M.; Besien, T.

2005-01-01

194

Time-division SQUID multiplexers with reduced sensitivity to external magnetic fields  

CERN Document Server

Time-division SQUID multiplexers are used in many applications that require exquisite control of systematic error. One potential source of systematic error is the pickup of external magnetic fields in the multiplexer. We present measurements of the field sensitivity figure of merit, effective area, for both the first stage and second stage SQUID amplifiers in three NIST SQUID multiplexer designs. These designs include a new variety with improved gradiometry that significantly reduces the effective area of both the first and second stage SQUID amplifiers.

Stiehl, G M; Hilton, G C; Irwin, K D; Mates, J A B; Reintsema, C D; Zink, B L

2010-01-01

195

Refractory cardiopulmonary failure after glyphosate surfactant intoxication: a case report  

OpenAIRE

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. Meta...

Chang Chia-Chu; Chang Chirn-Bin

2009-01-01

196

Identification of Glyphosate Resistance in Lolium rigidum Gaudin  

OpenAIRE

Glyphosate resistance was found in Lolium rigidum Gaudin (Rigid ryegrass, LOLRI) in South Africa. Suspected glyphosate-resistant L. rigidum populations were collected and grown under greenhouse conditions. The plants were sprayed with a range of doses of glyphosate 35 days after planting and shoot dry biomass was determined 17 days after herbicide treatment. Based on the dose-response experiment conducted in the greenhouse, one population of L. rigidum susp...

Danijela Pavlovi?; Charlie Reinhardt; Igor Elezovi?; Sava Vrbni?anin

2011-01-01

197

Metabolism of glyphosate in Pseudomonas sp. strain LBr.  

OpenAIRE

Metabolism of glyphosate (N-phosphonomethylglycine) by Pseudomonas sp. strain LBr, a bacterium isolated from a glyphosate process waste stream, was examined by a combination of solid-state 13C nuclear magnetic resonance experiments and analysis of the phosphonate composition of the growth medium. Pseudomonas sp. strain LBr was capable of eliminating 20 mM glyphosate from the growth medium, an amount approximately 20-fold greater than that reported for any other microorganism to date. The bact...

Jacob, G. S.; Garbow, J. R.; Hallas, L. E.; Kimack, N. M.; Kishore, G. M.; Schaefer, J.

1988-01-01

198

PHYTO-MICROBIAL DEGRADATION OF GLYPHOSATE IN RIYADH AREA  

OpenAIRE

Greenhouse studies were conducted to determine the ability of plant Amaranth, Amaranthus caudate and two isolated bacterial strains from rhizosphere region for cleaning up glyphosate residues in soil and plants. The analytical study of the biodegradation of glyphosate was carried out in the laboratory conditions. Amaranth, Amaranthus caudate and two isolated bacterial strains namely Pseudomonas aeruginosa and Bacillus megaterium could degrade glyphosate in 5 days. These results suggested that...

Abdel-megeed, A.; Sadik, M. W.; Al-shahrani, H. O.; Ali, H. M.

2013-01-01

199

Fuzzy Controller Based Dvr To Mitigate Power Quaity And Reduce The Harmonics Distortion Of Sensitive Load  

Directory of Open Access Journals (Sweden)

Full Text Available PI controller is very common in the control of DVRs. However, one disadvantage of this conventional controller is its inability to still working well under a wider range of operating conditions. So, as a solution fuzzy controller is proposed. This paper discusses the design and simulation of dynamic voltage restorer for improve power quality and reduce the harmonics distortion of sensitive load. Power quality problem is an occur as a non-standard voltage, current and frequency. Electronics devices are very sensitive load against harmonics. In power system voltage sag, swell, flicker and harmonics are some of the problem to the sensitive load. The compensation capability of a DVR depends primarily on the maximum voltage injection ability and the amount of stored energy available within the restorer. This device is connected in series with the distribution feeder at medium voltage. A fuzzy logic control is proposed. Simulation result carried out by Matlab/Simulink verifies the performance of the proposed method.

SANDESH JAIN

2013-05-01

200

Evaluation of reduced allergenicity of irradiated peanut extract using splenocytes from peanut-sensitized mice  

International Nuclear Information System (INIS)

Peanut (PN) allergy is one of the most serious forms of IgE-mediated food hypersensitivity. Gamma irradiation has been widely used for the preservation of food. The results of our previous studies showed that the IgE-binding capacity to several antigens were profoundly reduced after gamma irradiation. In this study, we evaluated the changes of allergenecity and cytokine production profiles after exposure of irradiated PN extract in a PN-allergy mouse model. Mice were sensitized to PN extract by intragastric administration on days 0, 1, 2, and 7, and then challenged on day 21. Four weeks later, we evaluated the cytokine production patterns and proliferation responses of splenocytes that were stimulated with intact PN extract, compared to 10 and 50 kGy irradiated PN extract. When the cells were stimulated with 10 kGy of irradiated PN extract, a higher level of production of IFN-? and IL-10 cytokines was observed. However, stimulation with 50 kGy of irradiated PN extract resulted in a higher level of production of only IFN-? cytokines. In addition, the Th1/Th2 ratio increased in response to treatment with gamma-irradiated PNs. The results of this study show that the allergenicity of PN extracts could be reduced by gamma irradiation which caused downregulation of Th2 lymphocyte activity in the PN-sensitized mice.

201

Evaluation of reduced allergenicity of irradiated peanut extract using splenocytes from peanut-sensitized mice  

Energy Technology Data Exchange (ETDEWEB)

Peanut (PN) allergy is one of the most serious forms of IgE-mediated food hypersensitivity. Gamma irradiation has been widely used for the preservation of food. The results of our previous studies showed that the IgE-binding capacity to several antigens were profoundly reduced after gamma irradiation. In this study, we evaluated the changes of allergenecity and cytokine production profiles after exposure of irradiated PN extract in a PN-allergy mouse model. Mice were sensitized to PN extract by intragastric administration on days 0, 1, 2, and 7, and then challenged on day 21. Four weeks later, we evaluated the cytokine production patterns and proliferation responses of splenocytes that were stimulated with intact PN extract, compared to 10 and 50 kGy irradiated PN extract. When the cells were stimulated with 10 kGy of irradiated PN extract, a higher level of production of IFN-{gamma} and IL-10 cytokines was observed. However, stimulation with 50 kGy of irradiated PN extract resulted in a higher level of production of only IFN-{gamma} cytokines. In addition, the Th1/Th2 ratio increased in response to treatment with gamma-irradiated PNs. The results of this study show that the allergenicity of PN extracts could be reduced by gamma irradiation which caused downregulation of Th2 lymphocyte activity in the PN-sensitized mice.

Oh, Sejo; Jang, Da-In [Department of Pediatrics, Ajou University School of Medicine, Suwon 442-749 (Korea, Republic of); Lee, Ju-Woon; Kim, Jae-Hun; Byun, Myung-Woo [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Lee, Soo-Young [Department of Pediatrics, Ajou University School of Medicine, Suwon 442-749 (Korea, Republic of)], E-mail: jsjs87@ajou.ac.kr

2009-07-15

202

A cost sensitive inpatient bed reservation approach to reduce emergency department boarding times.  

Science.gov (United States)

Emergency departments (ED) in hospitals are experiencing severe crowding and prolonged patient waiting times. A significant contributing factor is boarding delays where admitted patients are held in ED (occupying critical resources) until an inpatient bed is identified and readied in the admit wards. Recent research has suggested that if the hospital admissions of ED patients can be predicted during triage or soon after, then bed requests and preparations can be triggered early on to reduce patient boarding time. We propose a cost sensitive bed reservation policy that recommends optimal bed reservation times for patients. The policy relies on a classifier that estimates the probability that the ED patient will be admitted using the patient information collected and readily available at triage or right after. The policy is cost sensitive in that it accounts for costs associated with patient admission prediction misclassification as well as costs associated with incorrectly selecting the reservation time. Results from testing the proposed bed reservation policy using data from a VA Medical Center are very promising and suggest significant cost saving opportunities and reduced patient boarding times. PMID:24811547

Qiu, Shanshan; Chinnam, Ratna Babu; Murat, Alper; Batarse, Bassam; Neemuchwala, Hakimuddin; Jordan, Will

2015-03-01

203

Manejo de tiririca e trapoeraba com glyphosate em ambientes sombreados / Commelina benghalensis and Cyperus rotundus treated with glyphosate in shaded environments  

Scientific Electronic Library Online (English)

Full Text Available Plantas daninhas mantidas em ambientes com redução da intensidade luminosa apresentam alterações morfofisiológicas marcantes, que podem alterar seu comportamento reprodutivo e a tolerância a herbicidas aplicados em pós-emergência. Objetivou-se neste estudo avaliar a eficiência de doses de glyphosate [...] no manejo da trapoeraba (Commelina benghalensis) e da tiririca (Cyperus rotundus) cultivadas em diferentes níveis de sombreamento. O trabalho foi composto por dois ensaios, referentes a cada uma das espécies, com o mesmo delineamento experimental, sendo constituídos em esquema fatorial 5 x 3, com cinco doses de herbicida (0, 540, 810, 1.080 ou 1.350 g ha-1 de glyphosate), três ambientes de cultivo (0, 30 ou 50% de sombra) e quatro repetições. As parcelas experimentais foram compostas por um vaso com duas plantas de tiririca ou de trapoeraba. As avaliações de controle ocorreram aos 10, 20 e 30 dias após a aplicação (DAA), por meio de observações visuais. Aos 30 DAA, foi determinada a massa seca da parte aérea de cada espécie. A produtividade de tubérculos foi observada pela contagem direta desses propágulos presentes nas raízes das plantas de tiririca. Já a sua viabilidade foi avaliada por teste de germinação em leito de areia e por tetrazólio no caso dos não germinados. O controle das espécies foi mais eficiente em ambientes sombreados, contribuindo para a redução de até 25% da dose recomendada para ambas, obtendo-se controle de 81% para trapoeraba e 100% para tiririca. Já a matéria seca da parte aérea, a produtividade e a viabilidade dos tubérculos foram afetadas pelo aumento do nível de sombra e pela dose de glyphosate. A diminuição da intensidade luminosa - comum no sub-bosque de culturas arbóreas e arbustivas ou quando do adensamento de cultivos - representa prática interessante na supressão da trapoeraba e da tiririca e potencializa a ação de controle do glyphosate. Abstract in english Weeds maintained in reduced light intensity environments present remarkable morpho-physiological changes that may alter their reproductive behavior and tolerance to post-emergence herbicides. Our goal was to evaluate the efficiency of glyphosate doses in the management of Commelina benghalensis and [...] Cyperus rotundus grown at different levels of shading. The work consisted of two trials for each species with the same experimental design, in a 5 x 3 factorial design with five herbicide doses (0, 540, 810, 1.080, and 1.350 gha-1 of glyphosate), three cultivation environments (0, 30, or 50% of shading) and four replicates. Experimental plots consisted of a vase with two plants of either C. benghalensis or C. rotundus. Control evaluations were carried out 10, 20, and 30 days after application (DAA) through visual observations. Tuber productivity was verified by direct counting of these propagules present in the roots of C. rotundus plants, while tuber viability was evaluated by germination test in a sand bed, and by tetrazolium, for the non-germinated tubers. Species control was more efficient in shade environments, contributing to a reduction of up to 25% of the recommended dose for the treated species, and resulting in a control of 81% for C. benghalensis and 100% for C. rotundus. Aerial part dry biomass and productivity and viability of tubers were affected by increase in shade level and glyphosate dose. Reduced light intensity - common in the under-story of tree and shrub cultures or in culture density - is an interesting practice aiming at suppressing C. benghalensis and C. rotundus, acting as a potential control of glyphosate.

A, Santos Júnior; L.D, Tuffi Santos; G.A, Costa; E.A, Barbosa; G.L.D, Leite; V.D, Machado; L.R, Cruz.

2013-03-01

204

Manejo de tiririca e trapoeraba com glyphosate em ambientes sombreados Commelina benghalensis and Cyperus rotundus treated with glyphosate in shaded environments  

Directory of Open Access Journals (Sweden)

Full Text Available Plantas daninhas mantidas em ambientes com redução da intensidade luminosa apresentam alterações morfofisiológicas marcantes, que podem alterar seu comportamento reprodutivo e a tolerância a herbicidas aplicados em pós-emergência. Objetivou-se neste estudo avaliar a eficiência de doses de glyphosate no manejo da trapoeraba (Commelina benghalensis e da tiririca (Cyperus rotundus cultivadas em diferentes níveis de sombreamento. O trabalho foi composto por dois ensaios, referentes a cada uma das espécies, com o mesmo delineamento experimental, sendo constituídos em esquema fatorial 5 x 3, com cinco doses de herbicida (0, 540, 810, 1.080 ou 1.350 g ha-1 de glyphosate, três ambientes de cultivo (0, 30 ou 50% de sombra e quatro repetições. As parcelas experimentais foram compostas por um vaso com duas plantas de tiririca ou de trapoeraba. As avaliações de controle ocorreram aos 10, 20 e 30 dias após a aplicação (DAA, por meio de observações visuais. Aos 30 DAA, foi determinada a massa seca da parte aérea de cada espécie. A produtividade de tubérculos foi observada pela contagem direta desses propágulos presentes nas raízes das plantas de tiririca. Já a sua viabilidade foi avaliada por teste de germinação em leito de areia e por tetrazólio no caso dos não germinados. O controle das espécies foi mais eficiente em ambientes sombreados, contribuindo para a redução de até 25% da dose recomendada para ambas, obtendo-se controle de 81% para trapoeraba e 100% para tiririca. Já a matéria seca da parte aérea, a produtividade e a viabilidade dos tubérculos foram afetadas pelo aumento do nível de sombra e pela dose de glyphosate. A diminuição da intensidade luminosa - comum no sub-bosque de culturas arbóreas e arbustivas ou quando do adensamento de cultivos - representa prática interessante na supressão da trapoeraba e da tiririca e potencializa a ação de controle do glyphosate.Weeds maintained in reduced light intensity environments present remarkable morpho-physiological changes that may alter their reproductive behavior and tolerance to post-emergence herbicides. Our goal was to evaluate the efficiency of glyphosate doses in the management of Commelina benghalensis and Cyperus rotundus grown at different levels of shading. The work consisted of two trials for each species with the same experimental design, in a 5 x 3 factorial design with five herbicide doses (0, 540, 810, 1.080, and 1.350 gha-1 of glyphosate, three cultivation environments (0, 30, or 50% of shading and four replicates. Experimental plots consisted of a vase with two plants of either C. benghalensis or C. rotundus. Control evaluations were carried out 10, 20, and 30 days after application (DAA through visual observations. Tuber productivity was verified by direct counting of these propagules present in the roots of C. rotundus plants, while tuber viability was evaluated by germination test in a sand bed, and by tetrazolium, for the non-germinated tubers. Species control was more efficient in shade environments, contributing to a reduction of up to 25% of the recommended dose for the treated species, and resulting in a control of 81% for C. benghalensis and 100% for C. rotundus. Aerial part dry biomass and productivity and viability of tubers were affected by increase in shade level and glyphosate dose. Reduced light intensity - common in the under-story of tree and shrub cultures or in culture density - is an interesting practice aiming at suppressing C. benghalensis and C. rotundus, acting as a potential control of glyphosate.

A Santos Júnior

2013-03-01

205

Intoxicação de espécies de eucalipto submetidas à deriva do glyphosate Intoxication of eucalypt species under glyphosate drift  

OpenAIRE

O glyphosate é o herbicida mais utilizado em áreas de reflorestamento de eucalipto. Nessas áreas tem sido freqüente a verificação de sintomas de intoxicação devido à deriva. Entretanto, trabalhos de pesquisa e observações de campo indicam comportamento diferencial entre as espécies e os clones de eucalipto quando em contato com o glyphosate. O presente trabalho teve como objetivo avaliar os efeitos da deriva simulada de glyphosate, por meio de doses reduzidas, no crescimento de ci...

Tuffi Santos, L. D.; Ferreira, F. A.; Ferreira, L. R.; Duarte, W. M.; Tiburcio, R. A. S.; Santos, M. V.

2006-01-01

206

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

OpenAIRE

O glyphosate é o herbicida mais usado no controle de plantas daninhas em eucalipto, atuando diretamente na rota do ácido chiquímico, principal via de formação de compostos ligados aos mecanismos de defesa das plantas, como: lignina, ácido salicítico e fitoalexinas. Assim, o contato do glyphosate com as folhas do eucalipto pode levar a conseqüências importantes sobre a resistência a doenças. Objetivou-se neste estudo avaliar o envolvimento do glyphosate, via deriva, na severidade da...

Tuffi Santos, L. D.; Neves Grac?a, R.; Alfenas, A. C.; Ferreira, F. A.; Ferreira, L. R.; Oda, S.

2007-01-01

207

Controle de plantas daninhas na cultura de soja resistente ao glyphosate Weed control in glyphosate tolerant soybean crop  

OpenAIRE

O objetivo da pesquisa foi avaliar o controle de plantas daninhas em área cultivada com soja resistente ao herbicida glyphosate, sem a utilização de práticas complementares de manejo de plantas daninhas. Foram desenvolvidos experimentos, em condições de campo, nos anos agrícolas 2005/2006 e 2006/2007 em Jaboticabal (SP). Foram avaliadas duas cultivares de soja resistentes ao glyphosate (CD 214 RR e M-SOY 8008 RR), oito tratamentos de herbicidas (glyphosate, em aplicação única, nas d...

Núbia Maria Correia; Julio Cezar Durigan

2010-01-01

208

Translocação do glyphosate em biótipos de azevém (Lolium multiflorum) Glyphosate translocation in Italian ryegrass biotypes (Lolium multiflorum)  

OpenAIRE

Foram avaliadas neste trabalho a absorção foliar e a translocação do glyphosate por biótipos de azevém (Lolium multiflorum) sensíveis e resistentes a esse herbicida. Para isso, aplicou-se 14C-glyphosate utilizando-se uma microsseringa de precisão, adicionando-se 10 µL da calda sobre a face adaxial da primeira folha com lígula totalmente visível, quando as plantas de azevém se apresentavam com três perfilhos. A quantidade de glyphosate absorvido e translocado foi avaliada em inter...

Ferreira, E. A.; Santos, J. B.; Silva, A. A.; Oliveira, J. A.; Vargas, L.

2006-01-01

209

Resposta de plantas de beterraba (Beta vulgaris) e de cenoura (Daucus carota) à deriva simulada de glyphosate e clomazone / Response of beetroot (Beta vulgaris) and carrot (Daucus carota) to simulated glyphosate and clomazone drift  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Várias espécies de hortaliças são de muita importância para a alimentação humana e tornam-se alvos da deriva de herbicidas, pois comumente são cultivadas nas proximidades de culturas como arroz, soja e milho, pulverizadas com esses produtos. Neste trabalho, objetivou-se verificar possíveis efeitos d [...] e doses reduzidas dos herbicidas glyphosate e clomazone sobre plantas de beterraba (Beta vulgaris) e de cenoura (Daucus carota), em diferentes fases de desenvolvimento. As doses avaliadas dos herbicidas foram de 0, 5, 10, 15 e 20% da dose recomendada, equivalentes a 0, 63, 126, 189 e 252 g ha-1 de glyphosate e 0, 14,4, 28,8, 43,2 e 57,6 g ha-1 de clomazone, respectivamente, aplicadas aos 20, 30 e 40 dias após a emergência das culturas. Observou-se aumento no percentual de fitotoxicidade do glyphosate com o incremento na dose do herbicida, e a maior suscetibilidade ocorreu com a deriva nos estádios mais precoces, em ambas as espécies. As doses de clomazone não causaram qualquer sintoma detectável visualmente para as plantas de beterraba e de cenoura. Os resultados sugerem que o herbicida glyphosate causa injúrias às plantas de beterraba e cenoura, independentemente do estádio em que ocorre a interceptação do produto. No entanto, o herbicida clomazone não interfere no desenvolvimento inicial de plantas de beterraba e cenoura. Abstract in english Herbicide drift over horticultural crops is a common problem in the state of Rio Grande do Sul, mainly in areas near rice, soybean and corn fields. The objective of this research was to evaluate glyphosate and clomazone drift effects on beetroot (Beta vulgaris) and carrot (Daucus carota) plants. The [...] herbicides were sprayed at three different growth stages: 20, 30 and 40 days after seedling emergence. Herbicide rates evaluated were 0, 5, 10, 15, and 20% of the label rate. The sprayed rates were 0, 63, 126, 189 and 252 g ha-1 of glyphosate and 0.0, 14.4, 28.8, 43.2 and 57.6 g ha-1 of clomazone. Glyphosate injury to beetroot and carrot increased with herbicide rate, with the highest injury being observed at the earlier growth stage. Clomazone did not injure beetroot and carrot plants at any tested rate or growth stage. The results of this study suggest that glyphosate drift damages beetroot and carrot at any growth stage. However, beetroot and carrot are not sensitive to clomazone drift.

R.P., Rogoli; L.C., Fontana; S.S., Figueredo; J.A., Noldin.

2008-06-01

210

Resposta de plantas de beterraba (Beta vulgaris e de cenoura (Daucus carota à deriva simulada de glyphosate e clomazone Response of beetroot (Beta vulgaris and carrot (Daucus carota to simulated glyphosate and clomazone drift  

Directory of Open Access Journals (Sweden)

Full Text Available Várias espécies de hortaliças são de muita importância para a alimentação humana e tornam-se alvos da deriva de herbicidas, pois comumente são cultivadas nas proximidades de culturas como arroz, soja e milho, pulverizadas com esses produtos. Neste trabalho, objetivou-se verificar possíveis efeitos de doses reduzidas dos herbicidas glyphosate e clomazone sobre plantas de beterraba (Beta vulgaris e de cenoura (Daucus carota, em diferentes fases de desenvolvimento. As doses avaliadas dos herbicidas foram de 0, 5, 10, 15 e 20% da dose recomendada, equivalentes a 0, 63, 126, 189 e 252 g ha-1 de glyphosate e 0, 14,4, 28,8, 43,2 e 57,6 g ha-1 de clomazone, respectivamente, aplicadas aos 20, 30 e 40 dias após a emergência das culturas. Observou-se aumento no percentual de fitotoxicidade do glyphosate com o incremento na dose do herbicida, e a maior suscetibilidade ocorreu com a deriva nos estádios mais precoces, em ambas as espécies. As doses de clomazone não causaram qualquer sintoma detectável visualmente para as plantas de beterraba e de cenoura. Os resultados sugerem que o herbicida glyphosate causa injúrias às plantas de beterraba e cenoura, independentemente do estádio em que ocorre a interceptação do produto. No entanto, o herbicida clomazone não interfere no desenvolvimento inicial de plantas de beterraba e cenoura.Herbicide drift over horticultural crops is a common problem in the state of Rio Grande do Sul, mainly in areas near rice, soybean and corn fields. The objective of this research was to evaluate glyphosate and clomazone drift effects on beetroot (Beta vulgaris and carrot (Daucus carota plants. The herbicides were sprayed at three different growth stages: 20, 30 and 40 days after seedling emergence. Herbicide rates evaluated were 0, 5, 10, 15, and 20% of the label rate. The sprayed rates were 0, 63, 126, 189 and 252 g ha-1 of glyphosate and 0.0, 14.4, 28.8, 43.2 and 57.6 g ha-1 of clomazone. Glyphosate injury to beetroot and carrot increased with herbicide rate, with the highest injury being observed at the earlier growth stage. Clomazone did not injure beetroot and carrot plants at any tested rate or growth stage. The results of this study suggest that glyphosate drift damages beetroot and carrot at any growth stage. However, beetroot and carrot are not sensitive to clomazone drift.

R.P. Rogoli

2008-06-01

211

Synthesis of cyclodextrin-reduced graphene oxide hybrid nanosheets for sensitivity enhanced electrochemical determination of diethylstilbestrol  

International Nuclear Information System (INIS)

Highlights: ? ?-CD-RGO hybrid nanosheets were successfully prepared by using L-AA as the reducing agent under a mild condition. ? ?-CD-RGO/GCE greatly enhanced the electrochemical response of diethylstilbestrol (DES). ? DES can be detected with wide linear range and a low detection limit. ? ?-CD-RGO/GCE can be applied in real milk samples analysis with satisfactory results. - Abstract: ?-Cyclodextrin functionalized reduced graphene oxide hybrid nanosheets (?-CD-RGO) were successfully prepared by using L-ascorbic acid (L-AA) as the reducing agent under a mild condition and used as enhanced material for sensitivity determination of diethylstilbestrol (DES). In 0.1 M PBS (pH 7.0), the redox peak currents of DES increased significantly on ?-CD-RGO modified glassy carbon electrode (?-CD-RGO/GCE), suggesting that the composite film not only shows excellent electronic properties of RGO sheets but also exhibits high supramolecular recognition capability of ?-CD. The experimental conditions were optimized and the kinetic parameters were investigated. Under the optimal conditions, the reduction peak current of DES increased linearly with increasing the concentration in the range from 0.01 to 13 ?M with the detection limit of 4 nM (S/N = 3). The developed electrochemical sensor exhibited high selectivity, good stability and reproducibility, and also successfully determined DES in milk samples with satisfactory results.

212

Expectancy of Stress-Reducing Aromatherapy Effect and Performance on a Stress-Sensitive Cognitive Task  

Science.gov (United States)

Objective. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. This study examined stress-reducing effects of aromatherapy on cognitive function using the go/no-go (GNG) task performance and event related potentials (ERP) components sensitive to stress. The study also assessed the importance of expectancy in aromatherapy actions. Methods. 81 adults were randomized to 3 aroma groups (active experimental, detectable, and undetectable placebo) and 2 prime subgroups (prime suggesting stress-reducing aroma effects or no-prime). GNG performance, ERPs, subjective expected aroma effects, and stress ratings were assessed at baseline and poststress. Results. No specific aroma effects on stress or cognition were observed. However, regardless of experienced aroma, people receiving a prime displayed faster poststress median reaction times than those receiving no prime. A significant interaction for N200 amplitude indicated divergent ERP patterns between baseline and poststress for go and no-go stimuli depending on the prime subgroup. Furthermore, trends for beneficial prime effects were shown on poststress no-go N200/P300 latencies and N200 amplitude. Conclusion. While there were no aroma-specific effects on stress or cognition, these results highlight the role of expectancy for poststress response inhibition and attention. PMID:25802539

Chamine, Irina; Oken, Barry S.

2015-01-01

213

Fate and availability of glyphosate and AMPA in agricultural soil.  

Science.gov (United States)

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. PMID:18576216

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

2008-06-01

214

Suscetibilidade de genótipos de Lolium multiflorum ao herbicida glyphosate / Susceptibility of Lolium multiflorum genotypes to glyphosate  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Objetivou-se com este trabalho avaliar o grau de tolerância dos genótipos diploides e tetraploides de L. multiflorum (azevém) ao herbicida glyphosate. Para isso, foram instalados quatro experimentos, sendo um para cada estádio fenológico do azevém (duas folhas, quatro perfilhos, pré-florescimento e [...] formação de grãos). Utilizou-se delineamento em blocos casualizados com arranjo fatorial 2 x 6 (dois genótipos e seis doses do herbicida glyphosate: 240, 480, 960, 1.920, 3.840 e 7.680 g e.a. ha-1) e uma testemunha sem aplicação de glyphosate, com quatro repetições. Os parâmetros analisados foram porcentagem de controle e fitomassa seca da parte aérea das plantas. Os resultados foram submetidos à análise de variância e, em seguida, ajustados para modelo de curva de dose-resposta do tipo logística, sendo desses modelos calculados valores de controle correspondentes a 50, 80, 90 e 99%. Os genótipos de azevém diploide apresentaram suscetibilidade diferencial ao herbicida glyphosate, sendo o genótipo tetraploide mais tolerante ao herbicida que o diploide. O grau diferencial de tolerância, medido pelo fator de tolerância diferencial entre os genótipos, foi de 1,6 vez a dose de glyphosate no genótipo tetraploide em relação ao diploide. Os estádios fenológicos de desenvolvimento das plantas de ambos os genótipos afetaram o grau de tolerância ao glyphosate. A variável fitomassa seca das plantas apresentou a mesma tendência diferencial entre os genótipos diploides e tetraploides que o parâmetro porcentagem visual de controle. Abstract in english This work aimed to evaluate the degree of tolerance of Italian ryegrass genotypes to the herbicide glyphosate. Thus, four experiments were installed, one for each phenological stage (two leaves, four tillers, pre-flowering, and grain formation). The treatments consisted of the combination of the two [...] genotypes and six rates of glyphosate (240; 480; 960; 1,920; 3,840 and 7,680 g a.e. ha-1) and a check without glyphosate application, in a complete randomized block design and four replications. The parameters analyzed were control percentage and shoot dry biomass. Results were submitted to analysis of variance and subsequently adjusted to non-linear log of dose-response curves, and from these models control values were calculated at 50, 80, 90 and 99%. The Italian ryegrass genotypes presented differential susceptibility to the herbicide glyphosate, with the tetraploid genotype being more tolerant to the herbicide than the diploid. The degree of differential tolerance, measured by the differential tolerance factor between the genotypes, is 1.6 times the glyphosate dose in the tetraploid genotype compared to the diploid genotype. The phenological stages of plant development of both the genotypes studied affected the degree of tolerance to glyphosate. The variable shoot dry biomass presented the same differential tendency between the diploid and tetraploid genotypes presented by the parameter visual control percentage.

C.A., Dors; P.J., Christoffoleti; D.M., Sanchotene; A.C.R., Dias; P.A., Manfron; S.H.B., Dornelles.

2010-06-01

215

Draft Genome Sequence of Pseudomonas Strain P818, Isolated from Glyphosate-Polluted Soil  

OpenAIRE

Pseudomonas strain P818 was isolated from glyphosate-polluted soil in China. This bacterium presents a capacity for high glyphosate tolerance. We present the draft genome sequence of the strain Pseudomonas P818. The genes involved in the glyphosate tolerance were identified. This genomic information will facilitate the study of glyphosate tolerance mechanisms.

Cao, Gaoyi; Liu, Yunjun; Liu, Guiming; Wang, Jianhua; Wang, Guoying

2013-01-01

216

Reduced baroreflex sensitivity and pulmonary dysfunction in alcoholic cirrhosis: effect of hyperoxia  

DEFF Research Database (Denmark)

Patients with cirrhosis exhibit impaired regulation of the arterial blood pressure, reduced baroreflex sensitivity (BRS), and prolonged QT interval. In addition, a considerable number of patients have a pulmonary dysfunction with hypoxemia, impaired lung diffusing capacity (Dl(CO)), and presence of hepatopulmonary syndrome (HPS). BRS is reduced at exposure to chronic hypoxia such as during sojourn in high altitudes. In this study, we assessed the relation of BRS to pulmonary dysfunction and cardiovascular characteristics and the effects of hyperoxia. Forty-three patients with cirrhosis and 12 healthy matched controls underwent hemodynamic and pulmonary investigations. BRS was assessed by cross-spectral analysis of variabilities between blood pressure and heart rate time series. A 100% oxygen test was performed with the assessment of arterial oxygen tensions (Pa(O(2))) and alveolar-arterial oxygen gradient. Baseline BRS was significantly reduced in the cirrhotic patients compared with the controls (4.7 +/- 0.8vs. 10.3 +/- 2.0 ms/mmHg; P <0.001). The frequency-corrected QT interval was significantly prolonged in the cirrhotic patients (P <0.05). There was no significant difference in BRS according to presence of HPS, Pa(O(2)), Dl(CO), or Child-Turcotte score, but BRS correlated with metabolic and hemodynamic characteristics. After 100% oxygen inhalation, BRS and the QT interval remained unchanged in the cirrhotic patients. In conclusion, BRS is significantly reduced in patients with cirrhosis compared with controls, but it is unrelated to the degree of pulmonary dysfunction and portal hypertension. Acute hyperoxia does not significantly revert the low BRS or the prolonged QT interval in cirrhosis.

MØller, SØren; Iversen, J.S.

2010-01-01

217

Highly sensitive micromachined capacitive pressure sensor with reduced hysteresis and low parasitic capacitance  

DEFF Research Database (Denmark)

This paper describes the design and fabrication of a capacitive pressure sensor that has a large capacitance signal and a high sensitivity of 76 pF/bar in touch mode operation. Due to the large signal, problems with parasitic capacitances are avoided and hence it is possible to integrate the sensor with a discrete components electronics circuit for signal conditioning. Using an AC bridge electronics circuit a resolution of 8 mV/mbar is achieved. The large signal is obtained due to a novel membrane structure utilizing closely packed hexagonal elements. The sensor is fabricated in a process based on fusion bonding to create vacuum cavities. The exposed part of the sensor is perfectly flat such that it can be coated with corrosion resistant thin films. Hysteresis is an inherent problem in touch mode capacitive pressure sensors and a technique to significantly reduce it is presented.

Pedersen, Thomas; Fragiacomo, Giulio

2009-01-01

218

Hybrid reflection-transmission surface light-scattering instrument with reduced sensitivity to surface sloshing.  

Science.gov (United States)

A hybrid reflection-transmission surface light-scattering instrumental design is presented, examined theoretically, and tested experimentally. The purpose of the design is to reduce the sensitivity of the instrument to vibration in general and surface sloshing in particular while sacrificing little performance. Traditional optical arrangements and two new optical configurations with varying trade-offs between slosh resistance and instrumental simplicity and accuracy are examined by use of Fourier optics methods. The most promising design was constructed and tested with acetone, ethanol, and water as subject fluids. The test involved backcalculation of the wave number of the capillary wave examined with the known physical parameters for the test fluids. The agreement of the computed wave number was +/-1.4%. PMID:18264275

Meyer, W V; Lock, J A; Cheung, H M; Taylor, T W; Tin, P; Mann, J A

1997-10-20

219

Different causes of reduced sensitivity to thyroid hormone: diagnosis and clinical management.  

Science.gov (United States)

Normal thyroid hormone (TH) metabolism and action require adequate cellular TH signalling. This entails proper function of TH transporters in the plasma membrane, intracellular deiodination of TH and action of the bioactive hormone T3 at its nuclear receptors (TRs). The present review summarizes the discoveries of different syndromes with reduced sensitivity at the cellular level. Mutations in the TH transporter MCT8 cause psychomotor retardation and abnormal thyroid parameters. Mutations in the SBP2 protein, which is required for normal deiodination, give rise to a multisystem disorder including abnormal thyroid function tests. Mutations in TR?1 are a well-known cause of resistance to TH with mostly a mild phenotype, while only recently, patients with mutations in TR?1 were identified. The latter patients have slightly abnormal TH levels, growth retardation and cognitive defects. This review will describe the mechanisms of disease, clinical phenotype, diagnostic testing and suggestions for treatment strategies for each of these syndromes. PMID:23834164

Visser, W Edward; van Mullem, Alies A A; Visser, Theo J; Peeters, Robin P

2013-11-01

220

Buffer Layers May Reduce Recombination in Solid State Dye-Sensitized Solar Cells (Invited)  

Science.gov (United States)

The dye-sensitized solar cell is a new and renewable energy device that aims to compete with conventional fuels with its low cost and ease to manufacture. While the efficiencies of dye-sensitized solar cells are improving, they are not yet cost-competitive with current energy sources such as coal. Our project focuses on improving the efficiency of these organic solar cells by adding a self-assembled monolayer (SAM) in between the electron donor, a dye called Z907, and the semiconductor, nanoporous titania (TiO2). This SAM will theoretically reduce an unfavorable process called recombination, in which the light-excited electrons fall from their high-energy state directly back into the dye or hole-transport medium, instead of flowing through the circuit. The SAM molecules that we are using have a phosphonic acid head which should bind readily to the TiO2, and an amine group tail to tether the dye. To deposit the SAMs, the phosphonic acids are first dissolved in an organic solvent with the help of either acid (HCl) or base (KOH). We used Fourier Transform Infrared Spectroscopy (FTIR) to see what differences there were between acidic and basic deposition. FTIR analysis showed greater attachment of SAMs using acidic solutions rather than basic solutions for two out of the three SAMs. In the third, deposition was fairly even. By developing a reliable procedure to deposit SAMs onto titania, we will be able to more accurately test the effects of SAMs on dye-sensitized solar cells. This could improve the efficiencies of these organic devices and possibly offer a greener and cost-competitive alternative to fossil fuels.

Proctor, J.; Brennan, T.; Bakke, J.; Bent, S.

2009-12-01

221

Enthalpic partitioning of the reduced temperature sensitivity of O2 binding in bovine hemoglobin  

DEFF Research Database (Denmark)

The oxygenation enthalpy of the heme groups of hemoglobin (Hb) is inherently exothermic, resulting in decreased Hb-O2 affinity with rising temperature. However, oxygenation is coupled with endothermic dissociation of allosteric effectors (e.g. protons, chloride ions and organic phosphates) from the protein moiety, which thus reduces the overall oxygenation enthalpy. The evolution of Hbs with reduced temperature sensitivity ostensibly safeguards O2 unloading in cold extremities of regionally-heterothermic vertebrates permitting energy-saving reductions in heat loss. Ungulate (e.g. bovine) Hbs have long served as a model system in this regard in that they exhibit numerically low oxygenation enthalpies that are thought to correlate with the presence of an additional Cl(-) binding site (compared to human Hb) comprised of three cationic residues at positions 8, 76 and 77 of the ?-chains of Hb. However, ungulate Hbs also exhibit distinctive amino acid exchanges at the N-termini of the ?-chains that stabilize the low-affinity deoxystructure of the Hb, mimicking the action of organic phosphates. In order to assess the relative contributions from these two effects, we measured the temperature sensitivity of Hb-O2 affinity in bovine and human Hbs in the absence and presence of Cl(-) ions under strictly controlled pH conditions. The data indicate that Cl(-)-binding accounts for a minority (~30%) of the total reduction in the oxygenation enthalpy manifested in bovine compared to human Hb, whereas the majority of this reduction is ascribable to structural differences, including increased ?-chain hydrophobicity that would increase the heat of oxygenation-linked conformational change in bovine Hb.

Weber, Roy E; Fago, Angela

2014-01-01

222

A brief cognitive-behavioral approach to reducing anxiety sensitivity decreases pain-related anxiety.  

Science.gov (United States)

Anxiety sensitivity (AS; fear of anxiety-related sensations) is a known risk factor for anxiety disorders and recently has been linked to pain disorders. The present study was guided by the hypothesis that a program designed to reduce AS levels might also result in a decrease in anxiety related to pain sensations. Female undergraduates, selected as either high or low in AS according to screening scores on the Anxiety Sensitivity Index (ASI), were randomly assigned to participate in 3 1-hour, small group sessions of either cognitive behavioral therapy (CBT; psycho-education, cognitive restructuring, and interoceptive exposure) or a non-specific treatment (NST). Immediately prior to and following the intervention, participants completed the 20-item Pain Anxiety Symptoms Scale (PASS-20). Consistent with hypothesis, results revealed a 3-way interaction between AS group, intervention condition, and time on PASS-20 total scores. Only participants with high pre-morbid levels of AS assigned to the CBT condition showed a significant reduction in scores on the PASS-20 from pre- to post-treatment. Implications for improving CBT approaches for pain disorders are discussed. PMID:17189242

Watt, Margo C; Stewart, Sherry H; Lefaivre, Marie-Josée; Uman, Lindsay S

2006-01-01

223

Influência do Glyphosate sobre a nodulação e o crescimento de cultivares de soja resistente ao Glyphosate Glyphosate influence on growth and nodulation of Glyphosate resistant soybean cultivars  

OpenAIRE

A soja resistente ao glyphosate (RR) é uma tecnologia que vem acrescentar mais uma ferramenta ao manejo de plantas daninhas para essa cultura, que possui a maior área plantada em nosso país. Por se tratar de uma técnica recente tanto no Brasil quanto no mundo, é preciso estudos buscando informações para o uso correto desta importante e cada vez mais freqüente prática agrícola: o cultivo de soja transgênica. Objetivou-se com este trabalho avaliar os efeitos causados pelas aplicaçõ...

Oliveira Jr, R. S.; Dvoranen, E. C.; Constantin, J.; Cavalieri, S. D.; Franchini, L. H. M.; Rios, F. A.; Blainski, E.

2008-01-01

224

Metallic complexes with glyphosate: a review  

International Nuclear Information System (INIS)

We present studies involving metallic ions and the herbicide glyphosate. The metallic complexes of Cu(II), Zn(II), Mn(II), Ni(II), Cd(II), Pb(II), Cr(III), Fe(III), Co(III), ammonium, sodium, Ag(I), alkaline earth metals and of some lanthanides ions are described. The complexes are discussed in terms of their synthesis, identification, stability and structural properties, based on data from the current literature. (author)

225

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)

Full Text Available A glutationa S-transferase (GST, EC 2.5.1.18 desempenha um papel importante na resposta do estresse causado por herbicidas nas plantas; é considerada uma enzima de desintoxicação, por metabolizar grande variedade de compostos xenobióticos, por meio da conjugação destes com glutationa reduzida, formando substâncias de baixa toxicidade. O milho (Zea mays foi escolhido neste trabalho por apresentar problemas de injúrias quando submetido ao controle químico de plantas daninhas, por meio do uso de herbicidas. Esta pesquisa teve como objetivo determinar as alterações na atividade desta enzima em plantas de milho submetidas ao tratamento pelo herbicida glyphosate. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 4x4, com quatro tratamentos herbicidas (glyphosate nas concentrações de 1.000, 2.500 e 5.000 ppm e as plantas-controle tratadas com água e quatro estádios de desenvolvimento (9, 16, 23 e 30 dias após a emergência, com cinco repetições. O herbicida foi aplicado na parte aérea das plântulas de milho. A parte aérea foi coletada às 24, 48 e 72 horas após a aplicação do herbicida e utilizada para a determinação da atividade da GST e do teor de lipoperóxidos. Foi verificado que os teores de lipoperóxidos não foram alterados pelo tratamento com o glyphosate, porém a atividade de GST aumentou na maioria dos tratamentos utilizados, indicando ter ação na degradação do herbicida glyphosate em plantas de milho.Glutathione S-transferase (GST, EC 2.5.1.18 plays an important role in the response to stress caused by herbicides in plants; it is considered to be a detoxifying enzyme since it metabolizes a great variety of xenobiotic compounds, by combining them with reduced glutathione, forming substances of low toxicity. Maize (Zea mays was chosen in this work for showing injury problems when submitted to weed chemical control. This research aimed to determine the alterations in the 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.

A.C. Cataneo

2003-08-01

226

Synthesis of 15N labeled glyphosate  

International Nuclear Information System (INIS)

Amongst the actually commercialized herbicides the Glyphosate is the most used in Brazil. Its efficiency as well as the others herbicides against undesirable weeds is harmed by its final composts left at the environment. Although studies has being carried out to improve the knowledge about the herbicides behavior at the environment its complexity has led them towards innumerous to new significant research work where the use of radiolabeled composts (radiative tracers) are recommended to evaluate their bio-availability in the soil. However is the use, the manipulation and the storage of radiolabeled composts is requires an extra care under chemical safety point of view. The use of non radiolabeled composts is a world tendency especially for field researches. Under this context the presented work describes a method for the synthesis of 15N labeled glyphosate. The 15N-herbicide was undertaken by phosphometilation with the phosphit dialquil and 15N-glycine. The tests where carried out through a micro scale production plant and of equimolars amounts. At these conditions it's was possible to reach approximately a 20% of yield. At the conclusion of a best operational condition its expected to offer another important toll that shall be used in glyphosate behavior at the environment and undesirably weeds. (author)

227

Potato (Solanum tuberosum) response to simulated glyphosate drift  

Science.gov (United States)

Field studies were conducted in 2008 in Ontario, OR and Paterson, WA to determine the effect of simulated glyphosate drift on 'Ranger Russet' potato injury, shikimic acid accumulation, and tuber yield. Glyphosate was applied at 8.5-, 54-, 107-, 215-, and 423 g ae ha-1; which corresponds to 0.01, 0.0...

228

Soil Depth and Tillage Effects on Glyphosate Degradation  

Science.gov (United States)

The use of glyphosate-resistant crops facilitated the widespread adoption of no-tillage (NT) cropping systems. The experimental objectives were to determine glyphosate sorption, mineralization, and persistence at two depths [0- to 2- cm (A) and 2- to 10-cm (B)] in a silt loam managed under long ter...

229

Pitted and Hybrid Morningglory Accessions Have Variable Tolerance to Glyphosate  

Science.gov (United States)

Greenhouse studies were conducted to investigate the variability in tolerance to glyphosate among 38 accessions of pitted morningglory collected from several southern United States. Glyphosate at 420 g ae/ha was applied postemergence to plants at 4- to 5-leaf stage and control was visually estimated...

230

GLYPHOSATE-RESISTANT WEEDS: CURRENT STATUS AND FUTURE OUTLOOK  

Science.gov (United States)

Introduction of glyphosate-resistant transgenic crops has revolutionized weed management. GR crops as weed management tools have allowed farmers to manage weeds more effectively and economically. High levels of adoption of GR crops by U.S. farmers have dramatically increased the use of glyphosate,...

231

High-sensitive C-reactive protein is associated with reduced lung function in young adults  

DEFF Research Database (Denmark)

Systemic inflammation has been associated with reduced lung function. However, data on the interrelationships between lung function and inflammation are sparse, and it is not clear if low-grade inflammation leads to reduced lung function. Associations between high-sensitive C-reactive protein (CRP) and spirometric lung function were assessed in a population-based cohort of approximately 1,000 Danes aged 20 yrs. In males, the average decline in forced expiratory volume in one second (FEV(1)) in the highest CRP quintile was 23 mL.yr(-1) versus 1.6 mL.yr(-1) in the lowest quintile. In females, the average decline was 6.2 mL.yr(-1) in the highest CRP quintile versus an increase of 1.8 mL.yr(-1) in the lowest CRP quintile. In a multiple regression analysis adjusted for sex, body mass index, cardiorespiratory fitness, smoking, asthma, airway hyperresponsiveness and serum eosinophil cationic protein, higher levels of CRP at age 20 yrs were associated with a greater reduction in both FEV(1) and forced vital capacity between ages 20 and 29 yrs. The findings show that higher levels of C-reactive protein in young adults are associated with subsequent decline in lung function, suggesting that low-grade systemic inflammation in young adulthood may lead to impaired lung function independently of the effects of smoking, obesity, cardiorespiratory fitness, asthma and eosinophilic inflammation.

Rasmussen, F; Mikkelsen, D

2009-01-01

232

Study of glyphosate transport through suspended particulate matter  

Science.gov (United States)

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 complete (95% in 2 min). (ii) Kd obtained on the erodible fraction are two times higher than on 2 mm sieved soils. (iii) Desorption showed that glyphosate is desorbed from the erodible fraction at 40% after 25 desorptions. The aim of this study was to show the potential transport of glyphosate through suspended particulate matter. The adsorption on the erodible fraction argued to a significant transport potential of glyphosate on this fraction. The desorption of glyphosate from the erodible water fraction have revealed that the adsorption of glyphosate is reversible but it is much slower. These results demonstrate that glyphosate may be stored on the erodible fraction and be transported by these fractions. Keywords: Adsorption, Desorption, Glyphosate, Suspended Solids, Erosion.

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

2014-05-01

233

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

OpenAIRE

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...

Alexa, Ersilia; Micu, Roxana; Negrea, Monica; Sumalan, Renata; Iordanescu, Olimpia

2010-01-01

234

Effect of different doses of glyphosate in soybean  

Directory of Open Access Journals (Sweden)

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

S. A. Gomes

2013-07-01

235

Glyphosate tolerance of soybean mutant gained after boarding on satellite  

International Nuclear Information System (INIS)

Glyphosate-tolerant germplasm and genetic variation characteristics of SP2 and SP3 soybean varieties boarded on Shijian No.8 satellite were analyzed after treated by herbicide glyphosate in the field. Abundant variations of traits were produced, and the resistance within and among cultivars were different in their offspring of space mutagenesis. Plant height and maturity were used as index to screen glyphosate tolerant materials. Space mutation increased of soybean 661 SP3 of Zhongpin, and one glyphosate-resistance variant was screened from Zhongpin 661 SP3. It showed that glyphosate tolerance was different among offspring of different space mutagenesis soybean materials. It is feasible to systemically screen elite traits soybean by applying space mutation breeding. (authors)

236

Refractory cardiopulmonary failure after glyphosate surfactant intoxication: a case report  

Directory of Open Access Journals (Sweden)

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.

Chang Chia-Chu

2009-01-01

237

DISPERSION OF GLYPHOSATE IN SOILS UNDERGOING EROSION  

Directory of Open Access Journals (Sweden)

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 importance of the chemical and mineralogical nature of soils in the abatement and absorbency of glyphosate, and the poor results in case of erosive precipitations whwn soil structure and permeability are not favourable.

Gorana Todorovic Rampazzo

2010-08-01

238

Effect of Glyphosate-boron Application on Seed Composition and Nitrogen Metabolism in Glyphosate-resistant Soybean  

Science.gov (United States)

Information is limited on the effect of combined foliar application of glyphosate (Gly) and boron (B) on seed composition and nitrogen metabolism in glyphosate resistant soybean (Glycine max(L.)Merr.). Therefore, the objective of this two-year field study was to evaluate the effects of single foliar...

239

Glyphosate-based herbicides are toxic and endocrine disruptors in human cell lines.  

Science.gov (United States)

Glyphosate-based herbicides are the most widely used across the world; they are commercialized in different formulations. Their residues are frequent pollutants in the environment. In addition, these herbicides are spread on most eaten transgenic plants, modified to tolerate high levels of these compounds in their cells. Up to 400 ppm of their residues are accepted in some feed. We exposed human liver HepG2 cells, a well-known model to study xenobiotic toxicity, to four different formulations and to glyphosate, which is usually tested alone in chronic in vivo regulatory studies. We measured cytotoxicity with three assays (Alamar Blue, MTT, ToxiLight), plus genotoxicity (comet assay), anti-estrogenic (on ERalpha, ERbeta) and anti-androgenic effects (on AR) using gene reporter tests. We also checked androgen to estrogen conversion by aromatase activity and mRNA. All parameters were disrupted at sub-agricultural doses with all formulations within 24h. These effects were more dependent on the formulation than on the glyphosate concentration. First, we observed a human cell endocrine disruption from 0.5 ppm on the androgen receptor in MDA-MB453-kb2 cells for the most active formulation (R400), then from 2 ppm the transcriptional activities on both estrogen receptors were also inhibited on HepG2. Aromatase transcription and activity were disrupted from 10 ppm. Cytotoxic effects started at 10 ppm with Alamar Blue assay (the most sensitive), and DNA damages at 5 ppm. A real cell impact of glyphosate-based herbicides residues in food, feed or in the environment has thus to be considered, and their classifications as carcinogens/mutagens/reprotoxics is discussed. PMID:19539684

Gasnier, Céline; Dumont, Coralie; Benachour, Nora; Clair, Emilie; Chagnon, Marie-Christine; Séralini, Gilles-Eric

2009-08-21

240

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Objetivou-se neste trabalho avaliar o acúmulo de nutrientes e a translocação de glyphosate em biótipos de azevém. Para isso, foram montados dois ensaios: no primeiro aplicou-se 14C-glyphosate, adicionando 10 µL da calda sobre a face adaxial da primeira folha com lígula totalmente visível, quando as [...] plantas de azevém apresentavam três perfilhos. A quantidade de glyphosate absorvido, translocado e exsudado foi avaliada 64 horas após aplicação, por meio da medição da radiação emitida pelo 14C-glyphosate, em espectrômetro de cintilação líquida. O glyphosate foi quantificado em folha de aplicação, perfilhos, raízes e na solução nutritiva onde foram cultivados os biótipos de azevém. No segundo experimento, aplicou-se o glyphosate (480 g ha-1) tanto no biótipo sensível quanto no resistente. Após dez dias da aplicação, a parte área e as raízes das plantas foram coletadas e secas em estufa, sendo determinados os teores de macronutrientes. No primeiro ensaio, verificou-se exsudação radicular em ambos os biótipos, nos quais a quantidade de glyphosate exsudada foi semelhante, não ultrapassando 5% do total que penetrou na planta. No perfilho principal do biótipo sensível, comparado ao resistente, foi observada maior concentração do produto marcado. O biótipo resistente apresentou maior acúmulo de produto marcado na folha de aplicação; no sensível, a maior parte do glyphosate foi encontrada nas raízes. Com relação ao segundo ensaio, na presença de herbicida o biótipo sensível apresentou menor teor de fósforo tanto na parte aérea quanto na planta. Os biótipos resistente e sensível, sem aplicação de herbicida, tenderam a apresentar maiores teores de N total e N inorgânico na parte aérea e na planta como um todo, quando comparados aos tratamentos em que foi realizada a aplicação do produto. Ambos os biótipos mostraram a mesma capacidade de absorção e acúmulo de macronutrientes na ausência do produto. Abstract in english 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. Th [...] e 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.

E.A., Ferreira; A.A., Silva; M.R., Reis; J.B., Santos; J.A., Oliveira; L., Vargas; K.R., Khouri; A.A., Guimarães.

2008-03-01

241

INTERACTION OF A BIOHERBICIDE AND GLYPHOSATE FOR CONTROLLING HEMP SESBANIA IN GLYPHOSATE - RESISTANT SOYBEAN  

Science.gov (United States)

The bioherbicidal fungus Colletotrichum truncatum (Schwein.) Andrus & Moore was tested at different inoculum concentrations alone, and in combination with, prior to, or following treatment with different rates of glyphosate [N-(phosphonomethyl)glycine] (Roundup UltraTM) for control of hemp sesbania ...

242

Uso de aminoácido exógeno na prevenção de injúrias causadas por glyphosate na soja RR / Use of exogenous amino acid to prevent glyphosate injury in glyphosate-resistant soybean  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O aumento da área cultivada de soja resistente ao glyphosate (RR) no Brasil é resultado do benefício dessa tecnologia no manejo de plantas daninhas. No entanto, a expansão da área de soja RR aumentou significativamente o uso de glyphosate e consequentemente, em alguns casos, têm sido observados sint [...] omas de injúrias na soja RR conhecidos como yellow flashing ou amarelecimento das folhas superiores. Nesse sentido, dois experimentos, em diferentes anos, foram conduzidos em delineamento inteiramente casualizado, com quatro repetições. O primeiro teve o objetivo de avaliar a influência do glyphosate na soja RR nas variáveis fotossintéticas, nos parâmetros de nodulação e na biomassa seca da parte aérea e raiz, realizando-se a comparação entre os tratamentos BRS 242 RR sem glyphosate, BRS 242 RR + glyphosate e a isolinha parental não-RR cv. Embrapa 58, submetidas a uma dose de glyphosate de 1.200 g e.a. ha-1; aplicada no estádio V4. O segundo experimento foi conduzido visando reavaliar as variáveis fotossintéticas, de produção de biomassa e nodulação afetadas na soja RR pelo glyphosate no primeiro experimento. Entretanto, no segundo experimento foi avaliada a utilização de diversas modalidades de aplicação de aminoácidos (a.a.), sendo os diferentes tratamentos (sem a.a.; tratamento de semente com a.a; tratamento de semente com a.a. + aplicação foliar de a.a.; sem tratamento de sementes com a.a; e com aplicação foliar de a.a) combinados com diferentes doses de glyphosate (1.200 e 2.400 g e.a. ha-1), objetivando uma provável recuperação das plantas de soja com sua utilização exógena. Em ambos os experimentos, as variáveis fotossintéticas, os parâmetros de nodulação e biomassa seca da parte aérea e raiz foram afetados pela aplicação do glyphosate, porém o segundo experimento evidenciou, de modo geral, que o uso de aminoácidos via tratamento de sementes associado com aplicação foliar pode ser uma estratégia para prevenir os efeitos indesejáveis desse herbicida na cultura da soja RR. Abstract in english Cultivation of glyphosate-resistant (GR) soybeans has increased in Brazil as a result of the application of this technology in weed management systems developed for this crop. However, the expansion of GR soybean production has significantly increased the use of glyphosate and, in some cases, result [...] ed in injury symptoms observed in GR soybean, known as "yellow flashing" or yellowing of the upper leaves. Thus, two experiments were conducted in different years. The first experiment aimed to evaluate the influence of glyphosate on GR soybeans regarding the photosynthetic variables, nodule parameters, and shoot and root dry biomass by comparing cultivar BRS 242 GR without glyphosate and BRS 242 RR + glyphosate at 1.200 g ha-1 at V4 growth stage, to the near isogenic non-GR parental line cv. Embrapa 58. The second experiment aimed to reassess the same parameters in GR soybeans at the V4 stage treated with glyphosate, plus the application of various amino acids, to evaluate the expected recovery of soybean growth under the exogenous use of supplemental amino acids. In general, the photosynthetic variables, nodulation parameters and shoot and root dry biomass were affected by glyphosate; however, the use of amino acids may be a strategy to prevent the undesirable effects of this herbicide on GR soybean

L.H.S., Zobiole; R.S., Oliveira Jr.; J., Constantin; D.F., Biffe; R.J., Kremer.

243

High operating temperature IR-modules with reduced pitch for SWaP sensitive applications  

Science.gov (United States)

Low size, weight and power (SWaP) are the most critical requirements for portable thermal imagers like weapon sights or handheld observations devices. On the other hand due to current asymmetrical conflicts there are high requirements for the e/o performance of these devices providing the ability to distinguish between combatants and non-combatants in adequate ranges. Despite of all the success with uncooled technology, such requirements usually still require cooled detectors. AIM has developed a family of thermal weapon sights called HuntIR and RangIR based on high performance cooled IR-modules which are used e.g. in the infantryman of the future program of the German army (IdZ). The specific capability of these devices is a high ID range >1500m for tank targets being suitable in use as thermal sights for .50 cal rifles like the G82, targeting units for the 40mm AGL or for night observation. While such ranges sound far beyond the operational needs in urban operations, the a.m. specific needs of asymmetric warfare require sometimes even more range performance. High operating temperature (HOT) is introduced in the AIM MCT 640x512/15?m MWIR or LWIR modules for further reduction of cooler power consumption, shorter cooldown times and higher MTTF. As a key component to keep performance while further reducing SWaP AIM is developing a new cooled MCT IR-module with reduced pitch of 12 ?m operating at a temperature >120 K. The module will provide full TV format with 640x480 elements sensitive in the MWIR spectral band. The paper will show recent results of AIM IR-modules with high operating temperature and the impact of design regarding the IR-module itself and thermal sights making use of it.

Breiter, R.; Wendler, J.; Lutz, H.; Rutzinger, S.; Ihle, T.; Ziegler, J.; Rühlich, I.

2011-06-01

244

Mutation of NRAS but not KRAS significantly reduces myeloma sensitivity to single-agent bortezomib therapy.  

Science.gov (United States)

Various translocations and mutations have been identified in myeloma, and certain aberrations, such as t(4;14) and del17, are linked with disease prognosis. To investigate mutational prevalence in myeloma and associations between mutations and patient outcomes, we tested a panel of 41 known oncogenes and tumor suppressor genes in tumor samples from 133 relapsed myeloma patients participating in phase 2 or 3 clinical trials of bortezomib. DNA mutations were identified in 14 genes. BRAF as well as RAS genes were mutated in a large proportion of cases (45.9%) and these mutations were mutually exclusive. New recurrent mutations were also identified, including in the PDGFRA and JAK3 genes. NRAS mutations were associated with a significantly lower response rate to single-agent bortezomib (7% vs 53% in patients with mutant vs wild-type NRAS, P = .00116, Bonferroni-corrected P = .016), as well as shorter time to progression in bortezomib-treated patients (P = .0058, Bonferroni-corrected P = .012). However, NRAS mutation did not impact outcome in patients treated with high-dose dexamethasone. KRAS mutation did not reduce sensitivity to bortezomib or dexamethasone. These findings identify a significant clinical impact of NRAS mutation in myeloma and demonstrate a clear example of functional differences between the KRAS and NRAS oncogenes. PMID:24335104

Mulligan, George; Lichter, David I; Di Bacco, Alessandra; Blakemore, Stephen J; Berger, Allison; Koenig, Erik; Bernard, Hugues; Trepicchio, William; Li, Bin; Neuwirth, Rachel; Chattopadhyay, Nibedita; Bolen, Joseph B; Dorner, Andrew J; van de Velde, Helgi; Ricci, Deborah; Jagannath, Sundar; Berenson, James R; Richardson, Paul G; Stadtmauer, Edward A; Orlowski, Robert Z; Lonial, Sagar; Anderson, Kenneth C; Sonneveld, Pieter; San Miguel, Jesús F; Esseltine, Dixie-Lee; Schu, Matthew

2014-01-30

245

Moderately reduced graphene oxide as transparent counter electrodes for dye-sensitized solar cells  

International Nuclear Information System (INIS)

Moderately reduced graphene oxide (GO) films were fabricated by simple and fast thermal treatment of solution processed GO, and their application as an alternative to conventional Pt counter electrode in dye-sensitized solar cells (DSSCs) was investigated. GO without thermal treatment and thermally treated GO at 150 °C showed low efficiency of ?0.5%, whereas cell performance was significantly improved by applying thermal treatment over 250 °C. In particular, the DSSC with GO thermally treated at 350 °C exhibited the highest performance with open-circuit voltage (VOC) of 0.66 V, short-circuit current density (JSC) of 16.35 mA/cm2, F.F. of 33.33%, and overall power conversion efficiency (PCE) of 3.60%. Moderate reduction of GO by simple thermal treatment over 250 °C was confirmed through the measurements of X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). Enhancement of efficiency after high temperature thermal treatment might be attributed to the improved electrical conductivities and higher catalytic activities, resulting from the reduction of GO.

246

Glyphosate, pathways to modern diseases III: Manganese, neurological diseases, and associated pathologies  

Science.gov (United States)

Manganese (Mn) is an often overlooked but important nutrient, required in small amounts for multiple essential functions in the body. A recent study on cows fed genetically modified Roundup®-Ready feed revealed a severe depletion of serum Mn. Glyphosate, the active ingredient in Roundup®, has also been shown to severely deplete Mn levels in plants. Here, we investigate the impact of Mn on physiology, and its association with gut dysbiosis as well as neuropathologies such as autism, Alzheimer's disease (AD), depression, anxiety syndrome, Parkinson's disease (PD), and prion diseases. Glutamate overexpression in the brain in association with autism, AD, and other neurological diseases can be explained by Mn deficiency. Mn superoxide dismutase protects mitochondria from oxidative damage, and mitochondrial dysfunction is a key feature of autism and Alzheimer’s. Chondroitin sulfate synthesis depends on Mn, and its deficiency leads to osteoporosis and osteomalacia. Lactobacillus, depleted in autism, depend critically on Mn for antioxidant protection. Lactobacillus probiotics can treat anxiety, which is a comorbidity of autism and chronic fatigue syndrome. Reduced gut Lactobacillus leads to overgrowth of the pathogen, Salmonella, which is resistant to glyphosate toxicity, and Mn plays a role here as well. Sperm motility depends on Mn, and this may partially explain increased rates of infertility and birth defects. We further reason that, under conditions of adequate Mn in the diet, glyphosate, through its disruption of bile acid homeostasis, ironically promotes toxic accumulation of Mn in the brainstem, leading to conditions such as PD and prion diseases.

Samsel, Anthony; Seneff, Stephanie

2015-01-01

247

Glyphosate, pathways to modern diseases III: Manganese, neurological diseases, and associated pathologies.  

Science.gov (United States)

Manganese (Mn) is an often overlooked but important nutrient, required in small amounts for multiple essential functions in the body. A recent study on cows fed genetically modified Roundup(®)-Ready feed revealed a severe depletion of serum Mn. Glyphosate, the active ingredient in Roundup(®), has also been shown to severely deplete Mn levels in plants. Here, we investigate the impact of Mn on physiology, and its association with gut dysbiosis as well as neuropathologies such as autism, Alzheimer's disease (AD), depression, anxiety syndrome, Parkinson's disease (PD), and prion diseases. Glutamate overexpression in the brain in association with autism, AD, and other neurological diseases can be explained by Mn deficiency. Mn superoxide dismutase protects mitochondria from oxidative damage, and mitochondrial dysfunction is a key feature of autism and Alzheimer's. Chondroitin sulfate synthesis depends on Mn, and its deficiency leads to osteoporosis and osteomalacia. Lactobacillus, depleted in autism, depend critically on Mn for antioxidant protection. Lactobacillus probiotics can treat anxiety, which is a comorbidity of autism and chronic fatigue syndrome. Reduced gut Lactobacillus leads to overgrowth of the pathogen, Salmonella, which is resistant to glyphosate toxicity, and Mn plays a role here as well. Sperm motility depends on Mn, and this may partially explain increased rates of infertility and birth defects. We further reason that, under conditions of adequate Mn in the diet, glyphosate, through its disruption of bile acid homeostasis, ironically promotes toxic accumulation of Mn in the brainstem, leading to conditions such as PD and prion diseases. PMID:25883837

Samsel, Anthony; Seneff, Stephanie

2015-01-01

248

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)

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 (??g/l) in samples from Rands Ditch and Browns Ditch in DeSoto National Wildlife Refuge. Glyphosate was measured at the highest concentration (328 ??g/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 ??g/l. Aminomethylphosphonic acid, triclopyr, and nicosulfuron also were detected at concentrations greater than 3.0 ??g/l. ?? Springer Science+Business Media B.V. 2008.

Battaglin, W.A.; Rice, K.C.; Focazio, M.J.; Salmons, S.; Barry, R.X.

2009-01-01

249

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

Directory of Open Access Journals (Sweden)

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 practices for soybean rust control.

Rafael Moreira Soares

2008-04-01

250

Glyphosate em mistura com herbicidas alternativos para o manejo de plantas daninhas / Glyphosate combined with alternative herbicides for vegetation management  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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, fo [...] i 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. Abstract in english 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 mixtures of glyphosate combined with alternative mechanism of action herbicides [...] . An experiment was developed in a randomized complete design, using 12 treatments and four replications, under greenhouse conditions at University of São Paulo - USP/ESALQ - Piracicaba-SP, Brazil, with the weeds Richardia brasiliensis, Commelina benghalensis, Amaranthus hybridus, Galinsoga parviflora and Ipomoea grandifolia and applying glyphosate combined with the herbicides chlorimuron-ethyl, carfentrazone, bentazon, sulfentrazone and flumioxazin. The interactions were additive for the weeds I. grandifolia and C. benghalensis but the herbicides flumioxazin, sulfentrazone and carfentrazone sprayed alone and in mixture with glyphosate gave better control results. The interaction of glyphosate with sulfentrazone was antagonic in R. brasiliensis, whereas the glyphosate mixed with other herbicides was additive; however, the treatments using glyphosate and chlorimuron-ethyl or flumioxazin were more efficient in weed control. In A. hybridus, the best control results were glyphosate and carfentrazone alone and glyphosate mixed with flumioxazin, sulfentrazone, chlorimuron-ethyl and bentazon, all additives. In the case of G. parviflora, flumioxazin, sulfentrazone, chlorimuron and bentazon with glyphosate and flumioxazin and sulfentrazone gave excellent control.

P.A., Monquero; P.J., Christoffoleti; C.T.D., Santos.

2001-12-01

251

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)

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 mixtures of glyphosate combined with alternative mechanism of action herbicides. An experiment was developed in a randomized complete design, using 12 treatments and four replications, under greenhouse conditions at University of São Paulo - USP/ESALQ - Piracicaba-SP, Brazil, with the weeds Richardia brasiliensis, Commelina benghalensis, Amaranthus hybridus, Galinsoga parviflora and Ipomoea grandifolia and applying glyphosate combined with the herbicides chlorimuron-ethyl, carfentrazone, bentazon, sulfentrazone and flumioxazin. The interactions were additive for the weeds I. grandifolia and C. benghalensis but the herbicides flumioxazin, sulfentrazone and carfentrazone sprayed alone and in mixture with glyphosate gave better control results. The interaction of glyphosate with sulfentrazone was antagonic in R. brasiliensis, whereas the glyphosate mixed with other herbicides was additive; however, the treatments using glyphosate and chlorimuron-ethyl or flumioxazin were more efficient in weed control. In A. hybridus, the best control results were glyphosate and carfentrazone alone and glyphosate mixed with flumioxazin, sulfentrazone, chlorimuron-ethyl and bentazon, all additives. In the case of G. parviflora, flumioxazin, sulfentrazone, chlorimuron and bentazon with glyphosate and flumioxazin and sulfentrazone gave excellent control.

P.A. Monquero

2001-12-01

252

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  

OpenAIRE

Plantas de eucalipto com sintomas de intoxicação por glyphosate são comuns em áreas em que esse herbicida é usado. Uma das possíveis formas de contato com glyphosate é por meio da exsudação radicular do produto, por plantas daninhas tratadas, e subseqüente absorção pelas plantas de eucalipto. Objetivou-se com este trabalho avaliar a exsudação de glyphosate por Brachiaria decumbens e seus efeitos sobre plantas de eucalipto, por meio da aplicação de 14C-glyphosate misturado à c...

Tuffi Santos, L. D.; Santos, J. B.; Ferreira, F. A.; Oliveira, J. A.; Bentivenha, S.; Machado, A. F. L.

2008-01-01

253

Genotoxic effects of glyphosate or paraquat on earthworm coelomocytes.  

Science.gov (United States)

The potential genotoxicity (nuclear anomalies, damage to single-strand DNA) and pinocytic adherence activity of two (glyphosate-based and paraquat-based) commercial herbicides to earthworm coelomocytes (immune cells in the coelomic cavity) were assessed. Coelomocytes were extracted from earthworms (Pheretima peguana) exposed to concentrations glyphosate-based or paraquat-based herbicides on filter paper for 48 h. Three assays were performed: Micronucleus (light microscopy count of micronuclei, binuclei, and trinuclei), Comet (epifluorescent microscope and LUCIA image analyzer measure of tail DNA %, tail length, and tail moment), and Neutral Red (to detect phagocytic or pinocytic activity). The LC50 value for paraquat was 65-fold lower than for glyphosate indicating that paraquat was far more acutely toxic to P. peguana. There were significant (P glyphosate at 25 × 10(-1) (10(-3) LC50) and paraquat at 39 × 10(-5) (10(-4) LC50) ?g cm(-2) filter paper. In earthworms exposed to glyphosate, no differences in tail DNA%, tail length, and tail moment of coelomocytes were detected. In contrast, for paraquat at 10(-1) LC50 concentration, there were significant (P glyphosate or paraquat at 10(-3) LC50 concentration. This study showed that, at concentrations well below field application rates, paraquat induces both clastogenic and aneugenic effects on earthworm coelomocytes whereas glyphosate causes only aneugenic effects and therefore does not pose a risk of gene mutation in this earthworm. PMID:22644885

Muangphra, Ptumporn; Kwankua, Wimon; Gooneratne, Ravi

2014-06-01

254

Degradation of 14C-glyphosate in compost amended soils.  

Science.gov (United States)

Glyphosate (N-phosphonomethyl-glycine), the active ingredient in several herbicide formulations, is a non-selective, post-emergent herbicide used in a variety of crop and non-crop situations. Glyphosate is a non-volatile herbicide that is relatively immobile in soil. Its degradation is due to microbiological processes and most laboratory studies have been conducted with 14C-glyphosate with the rate of 14CO2 evolution being used as an indication of herbicide breakdown. In this paper we have studied the glyphosate degradation in compost amendment soils using Scientilator Liquid TRIATHLER and Glyphosate-phosphonomethyl-14C-labeled with specific activity 2,2mCi/mmol. Four types of soils have been taken under study: Black Chernozem, Vertisol, Gleysol and Phaeozem with different characteristics. For the each type of soil have been realized four experimental variants (glyphosate blind sample with 1,5 ppm, concentration, autoclaved soil, soil with glyphosate and addition of compost in field concentration of 40 t/ha, respectively 60 t/ha. The mineralization curves of 14CO2 accumulated were compared during of 40 days. All the mineralization curves for the soils exhibited same patterns, with only two phases, the initial rapid phase of degradation, for about 20 days, attributed to microbial action on the free glyphosate and the second slow phase, when the curves attained plateaus. Compost applied with different concentrations to Vertisol and Black Chernozem did not appear to stimulate the microbial degradation of glyphosate. In Gleysol and Phaeozem with lower humus content, the mineralization curve of 14C indicate the increase degradation capacity, expressed as accumulated 14CO2 as % total 14C, with the increase of compost concentration. PMID:20218528

Alexa, E; Bragea, M; Sumalan, R; Negrea, M; Lazureanu, A

2009-01-01

255

Determination of glyphosate and phosphate in water by ion chromatography--inductively coupled plasma mass spectrometry detection.  

Science.gov (United States)

Quantitative determination of trace glyphosate and phosphate in waters was achieved by coupling ion chromatography (IC) separation with inductively coupled plasma mass spectrometry (ICP-MS) detection. The separation of glyphosate and phosphate on a polymer anion-exchange column (Dionex IonPac AS16, 4.0 mm x 250 mm) was obtained by eluting them with 20 mM citric acid at 0.50 mL min(-1), and the analytes were detected directly and selectively by ICP-MS at m/z = 31. Parameters affecting their chromatographic behaviors and ICP-MS characteristics were systematically examined. Based on a 500-microL sample injection volume, the detection limits were 0.7 microgL(-1) for both glyphosate and phosphate, and the calibrations were linear up to 400 microgL(-1). Polyphosphates, aminomethylphosphonic acid (the major metabolite of glyphosate), non-polar and other polar phosphorus-containing pesticides showed different chromatographic behaviors from the analytes of interest and therefore did not interference. The determination was also interference free from the matrix anions (nitrate, nitrite, sulphate, chloride, etc.) and metallic ions. The analysis of certified reference material, drinking water, reservoir water and Newater yielded satisfactory results with spiked recoveries of 97.1-107.0% and relative standard deviations of < or = 7.4% (n = 3). Compared to other reported methods for glyphosate and phosphate, the developed IC-ICP-MS method is sensitive and simple, and does not require any chemical derivatization, sample preconcentration and mobile phase conductivity suppression. PMID:16185703

Guo, Zhong-Xian; Cai, Qiantao; Yang, Zhaoguang

2005-12-30

256

Glyphosate catabolism by Pseudomonas sp. strain PG2982.  

OpenAIRE

The pathway for the degradation of glyphosate (N-phosphonomethylglycine) by Pseudomonas sp. PG2982 has been determined by using metabolic radiolabeling experiments. Radiorespirometry experiments utilizing [3-14C]glyphosate revealed that approximately 50 to 59% of the C-3 carbon was oxidized to CO2. Fractionation of stationary-phase cells labeled with [3-14C]glyphosate revealed that from 45 to 47% of the assimilated label is distributed to proteins and that the amino acids methionine and serin...

Shinabarger, D. L.; Braymer, H. D.

1986-01-01

257

Adsorption of glyphosate and aminomethylphosphonic acid in soils  

Science.gov (United States)

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.

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

2013-03-01

258

Central fuel banking to reduce the number of proliferation sensitive enrichment activities  

International Nuclear Information System (INIS)

Central fuel banking is a complex international political, economic and technical concept that aims to reduce uncontrolled spreading of uranium enrichment technology in the world in order to prevent proliferation of nuclear weapons. This paper first gives an outline of the notions: 'non-proliferation', the 'front-end' of the fuel cycle, the scope of fuel baking, nuclear fuel and the 60 years of enrichment technology. Enrichment technology is highly concentrated in the nuclear weapon states and other developed countries, but this is not exclusive any more. The technology is spreading. The global demand for enrichment services - parallel to massive nuclear investments in the civil sector and the ageing of older facilities - is constantly growing. Proliferation sensitivity calls for an effective and comprehensive non-proliferation regime. The solution may be multilateralizing the nuclear fuel cycle. After a historical overview, the proposals on multilateral nuclear approaches are presented. The assessment of the proposals is complex in the dimensions of: the non-proliferation aim, the assurance of supply aspect and other variables such as legal issues and non-nuclear inducements. A general evaluation and the recommendations of the Expert Panel of the IAEA are introduced outlining a plan on a middle- and long-term basis. The conclusion of the paper stresses the importance and challenge in finding the 'new balance' between obligations and interests of the members of the glons and interests of the members of the global community stating that the answers will have a significant impact on the nuclear indus- try, world wide economics and security policy. (orig.)

259

Reduced baroreflex sensitivity in alcoholic cirrhosis: relations to hemodynamics and humoral systems  

DEFF Research Database (Denmark)

In cirrhosis, arterial vasodilatation leads to central hypovolemia and activation of the sympathetic nervous and renin-angiotensin-aldosterone systems. As the liver disease and circulatory dysfunction may affect baroreflex sensitivity (BRS), we assessed BRS in a large group of patients with cirrhosis and in controls who were all supine and some after 60 degrees passive head-up and 30 degrees head-down tilting in relation to central hemodynamics and activity of the sympathetic nervous and renin-angiotensin-aldosterone systems. One-hundred and five patients (Child classes A/B/C: 21/55/29) and 25 (n=11 + 14) controls underwent a full hemodynamic investigation. BRS was assessed by cross-spectral analysis of variabilities between blood pressure and heart rate time series. The median BRS was significantly lower in the supine cirrhotic patients, 3.7 (range 0.3-30.7) ms/mmHg than in matched controls (n=11): 14.3 (6.1-23.6) ms/mmHg, P<0.001. A stepwise multiple-regression analysis revealed that serum sodium (P=0.044),heart rate (P=0.027), and central circulation time (P=0.034) independently correlated with BRS. Head-down tilting had no effects on BRS, but, after head-up tilting, BRS was similar in the patients (n=23) and controls (n=14). In conclusion, BRS is reduced in cirrhosis in the supine position and relates to various aspects of cardiovascular dysfunction, but no further reduction was observed in parallel with the amelioration of the hyperdynamic circulation after head-up tilting. The results indicate that liver dysfunction and compensatory mechanisms to vasodilatation may be involved in the low BRS, which may contribute to poor cardiovascular adaptation in cirrhosis. Udgivelsesdato: 2007-Jun

MØller, SØren; Iversen, Jens S

2007-01-01

260

Glyphosate Control of Orange and Brown Rusts in Glyphosate-Sensitive Sugarcane Cultivars  

Science.gov (United States)

Technical Abstract: Brown and orange rust diseases cause substantial yield reductions on sugarcane (Saccharum spp.) in Florida and other regions where sugarcane is grown. Brown rust caused by Puccinia melanocephala Syd. & P. Syd has been present in Florida since 1978 and orange rust caused by Pucci...

261

Photoelectrochemical sensitization and spectroscopic properties of reduced and oxidized forms of a chlorophyll analogue  

International Nuclear Information System (INIS)

The photoelectrochemical sensitization of a large bandgap semiconductor has been achieved via excitation of a sensitizer, chlorophyllin (CPLN). The redox states that control the net charge transfer are characterized by pulse radiolysis. The spectroscopic and kinetic details of the pulse radiolytically generated CPLN.+ and CPLN.- are reported. (author)

262

Photoelectrochemical sensitization and spectroscopic properties of reduced and oxidized forms of a chlorophyll analogue  

Energy Technology Data Exchange (ETDEWEB)

The photoelectrochemical sensitization of a large bandgap semiconductor has been achieved via excitation of a sensitizer, chlorophyllin (CPLN). The redox states that control the net charge transfer are characterized by pulse radiolysis. The spectroscopic and kinetic details of the pulse radiolytically generated CPLN{sup .+} and CPLN{sup .-} are reported. (author).

Kamat, P.V. (Notre Dame Univ., IN (USA). Radiation Lab.); Chauvet, J.-P. (Notre Dame Univ., IN (USA). Radiation Lab. Ecole Normale Superieure, Lyon (France))

1991-01-01

263

Regional differences in time to pregnancy among fertile women from five Colombian regions with different use of glyphosate.  

Science.gov (United States)

The objective of this study was to test whether there was an association between the use of glyphosate when applied by aerial spray for the eradication of illicit crops (cocaine and poppy) and time to pregnancy (TTP) among fertile women. A retrospective cohort study (with an ecological exposure index) of first pregnancies was undertaken in 2592 fertile Colombian women from 5 regions with different uses of glyphosate. Women were interviewed regarding potential reproductive, lifestyle, and work history predictors of TTP, which was measured in months. Fecundability odds ratios (fOR) were estimated using a discrete time analogue of Cox's proportional hazard model. There were differences in TTP between regions. In the final multivariate model, the main predictor was the region adjusted by irregular relationship with partner, maternal age at first pregnancy, and, marginally, coffee consumption and self-perception of water pollution. Boyaca, a region with traditional crops and. recently, illicit crops without glyphosate eradication spraying (manual eradication), displayed minimal risk and was the reference region. Other regions, including Sierra Nevada (control area, organic agriculture), Putumayo and Narino (illicit crops and intensive eradication spray program), and Valle del Cauca, demonstrated greater risk of longer TTP, with the highest risk for Valle del Cauca (fOR 0.15, 95% CI 0.12, 0.18), a sugar-cane region with a history of use of glyphosate and others chemicals for more than 30 yr. The reduced fecundability in some regions was not associated with the use of glyphosate for eradication spraying. The observed ecological differences remain unexplained and may be produced by varying exposures to environmental factors, history of contraceptive programs in the region, or psychological distress. Future studies examining these or other possible causes are needed. PMID:19672763

Sanin, Luz-Helena; Carrasquilla, Gabriel; Solomon, Keith R; Cole, Donald C; Marshall, E J P

2009-01-01

264

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

Scientific Electronic Library Online (English)

Full Text Available Avaliou-se a resistência de dez genótipos de soja (Glycine max) ao herbicida glyphosate. Foi adotado o esquema fatorial 10 x 4, no delineamento em blocos casualizados, com quatro repetições. O fator A foi composto por dez genótipos de soja, e o B, por quatro doses de glyphosate. A aplicação do herbi [...] cida foi realizada no momento em que as plantas de soja apresentavam a segunda folha trifoliolada completamente desenvolvida. Avaliaramse os caracteres: intoxicação das plantas, número de nós da haste principal, altura das plantas e massa seca das plantas. Na avaliação da intoxicação de plantas, tanto aos quatro dias após a aplicação (DAA) do herbicida quanto aos 28 DAA, os genótipos convencionais apresentaram médias superiores estatisticamente em comparação com genótipos resistentes ao glyphosate (RR). Verificou-se que, nas avaliações realizadas ao 0 DAA ou aos 28 DAA sob 0,0 g e.a. ha¹, as respostas dos genótipos foram diferentes em todos os caracteres avaliados, com exceção do número de nós aos 28 DAA. Essas diferenças podem ser atribuídas aos efeitos fisiológicos e ambientais ou a características do próprio material. Nas demais doses, os genótipos RR comportaram-se de maneira desejável em detrimento dos genótipos convencionais. Ao considerar todos os caracteres avaliados, pode-se afirmar que Valiosa RR, BCR945G110, BCR945G114, BCR892G132, BCR892G140, BCR1067G210, BCR1070G244 e M-SOY 8008RR comportaram-se de forma semelhante quanto à resistência ao glyphosate quando submetidos até a dose de 2.160 g e.a. ha-1 . Abstract in english Resistance of ten soybean genotypes (Glycine max) to the herbicide glyphosate was evaluated. The randomized block experimental design was used under factorial scheme 10 x 4 and four replicates. Factor A was composed of 10 soybean genotypes and factor B of four glyphosate doses. The herbicide was app [...] lied when the second trifoliate leaf of the soybean plants was completely developed. The following characters 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 .

E, Matsuo; T, Sediyama; C.D, Cruz; A.A, Silva; R.C.T, Oliveira; A.P.O, Nogueira; F.D, Tancredi.

1063-10-01

265

Researches regarding extractable glyphosate residues from different soils.  

Science.gov (United States)

GLyphosate (N-phosphonomethyl-glycine) is a systemic, broad spectrum herbicide effective against most plant species, including annual and perennial species and is one of the world's most widely used herbicide. To glyphosate applied treatments, a part of active agent comes in contact with soil surface, adsorbing to soil compounds, while another part remains in soil solution. The adsorbing to soil compounds represents a feat importance conditioning the herbicide presence in soil solution and so, his availability to degradation and dispersion in the environment. In this paper work, the extractable glyphosate residues from soil solution have been determined through HPLC-FLD. Substrates used were Black Chernozem, Typical Gleysoil, Slight Vertisol, with moderate carbonatation. The experimental results indicated that the extractable glyphosate residue fractions from soil diminish (soil parameters and decrease in this order: Gleysoil, Black Chernozem, Slight Vertisol. PMID:19226836

Alexa, Ersilia; Lazureanu, Aurel; Alda, Simion; Negrea, Monica; Iordanescu, Olimpia

2008-01-01

266

Removal of glyphosate herbicide from water using biopolymer membranes.  

Science.gov (United States)

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 treat a water sample contaminated with glyphosate. Biopolymer membranes therefore potentially offer a versatile method to eliminate agricultural chemicals from water supplies. PMID:25585148

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

267

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

OpenAIRE

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...

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

2011-01-01

268

Resistência de azevém (Lolium multiflorum) ao herbicida glyphosate Resistance of italian ryegrass (Lolium multiflorum) to glyphosate  

OpenAIRE

O azevém é uma gramínea de ciclo anual, constituindo-se com freqüência em planta infestante em lavouras de trigo do Rio Grande do Sul. Em experimentos realizados em casa de vegetação e no campo, foi avaliada a suscetibilidade de dois biótipos de azevém ao herbicida glyphosate, bem como a eficiência de herbicidas de ação total na dessecação de Lolium multiflorum para a semeadura direta de trigo. O delineamento experimental foi completamente casualizado em casa de vegetação e de...

Roman, E. S.; Vargas, L.; Rizzardi, M. A.; Mattei, R. W.

2004-01-01

269

Reduced sensitivity to emotional prosody in congenital amusia rekindles the musical protolanguage hypothesis  

OpenAIRE

A number of evolutionary theories assume that music and language have a common origin as an emotional protolanguage that remains evident in overlapping functions and shared neural circuitry. The most basic prediction of this hypothesis is that sensitivity to emotion in speech prosody derives from the capacity to process music. We examined sensitivity to emotion in speech prosody in a sample of individuals with congenital amusia, a neurodevelopmental disorder characterized by deficits in proce...

Thompson, William Forde; Marin, Manuela M.; Stewart, Lauren

2012-01-01

270

Weight Loss Reduces Liver Fat and Improves Hepatic and skeletal Muscle Insulin sensitivity in Obese Adolescents  

OpenAIRE

Obesity in adolescents is associated with metabolic risk factors for type 2 diabetes, particularly insulin resistance and excessive accumulation of intrahepatic triglyceride (IHTG). The purpose of this study was to evaluate the effect of moderate weight loss on IHTG content and insulin sensitivity in obese adolescents who had normal oral glucose tolerance. Insulin sensitivity, assessed by using the hyperinsulinemic–euglycemic clamp technique in conjunction with stable isotopically labeled t...

Vitola, Bernadette E.; Deivanayagam, Sheela; Stein, Richard I.; Mohammed, Balsamanirina S.; Magkos, Faidon; Kirk, Erik P.; Klein, Samuel

2009-01-01

271

Electrochemically Reduced Graphene Oxide Multilayer Films as Efficient Counter Electrode for Dye-Sensitized Solar Cells  

OpenAIRE

We report on a new counter electrode for dye-sensitized solar cells (DSCs), which is prepared using layer-by-layer assembly of negatively charged graphene oxide and positively charged poly (diallyldimethylammonium chloride) followed by an electrochemical reduction procedure. The DSC devises using the heteroleptic Ru complex C106TBA as sensitizer and this new counter electrode reach power conversion efficiencies of 9.5% and 7.6% in conjunction with low volatility and solvent free ionic liquid ...

Xiaobao Xu; Dekang Huang; Kun Cao; Mingkui Wang; Zakeeruddin, Shaik M.; Michael Grätzel

2013-01-01

272

PHYTO-MICROBIAL DEGRADATION OF GLYPHOSATE IN RIYADH AREA  

Directory of Open Access Journals (Sweden)

Full Text Available Greenhouse studies were conducted to determine the ability of plant Amaranth, Amaranthus caudate and two isolated bacterial strains from rhizosphere region for cleaning up glyphosate residues in soil and plants. The analytical study of the biodegradation of glyphosate was carried out in the laboratory conditions. Amaranth, Amaranthus caudate and two isolated bacterial strains namely Pseudomonas aeruginosa and Bacillus megaterium could degrade glyphosate in 5 days. These results suggested that phytoremediation could accelerate the degradation of glyphosate residues in plants and in rhizosphere region as well. Glyphosate had strong effect on bacterial DNA where many DNA bands were affected. This could be explained that the effect of herbicide glyphosate on the protein profile may reflex somehow DNA mutation occurred during the assimilation of those toxic compounds. Therefore, the alteration occurred in both DNA and protein profiles is considered a degree of tolerance that lead to DNA mutation to cope with the assimilation of this compound. Therefore, the phytoremediation way could be a promising tool in program is to protect public health and the environment by ensuring the safety and availability of herbicides and pesticide alternatives.

ABDEL-MEGEED A.

2013-09-01

273

A glyphosate-based pesticide impinges on transcription  

International Nuclear Information System (INIS)

Widely spread chemicals used for human benefits may exert adverse effects on health or the environment, the identification of which are a major challenge. The early development of the sea urchin constitutes an appropriate model for the identification of undesirable cellular and molecular targets of pollutants. The widespread glyphosate-based pesticide affected sea urchin development by impeding the hatching process at millimolar range concentration of glyphosate. Glyphosate, the active herbicide ingredient of Roundup, by itself delayed hatching as judged from the comparable effect of different commercial glyphosate-based pesticides and from the effect of pure glyphosate addition to a threshold concentration of Roundup. The surfactant polyoxyethylene amine (POEA), the major component of commercial Roundup, was found to be highly toxic to the embryos when tested alone and therefore could contribute to the inhibition of hatching. Hatching, a landmark of early development, is a transcription-dependent process. Correlatively, the herbicide inhibited the global transcription, which follows fertilization at the 16-cell stage. Transcription inhibition was dose-dependent in the millimolar glyphosate range concentration. A 1257-bp fragment of the hatching enzyme transcript from Sphaerechinus granularis was cloned and sequenced; its transcription was delayed by 2 h in the pesticide-treated embryos. Because transcription is a fundamental basic biological process, the pesticide mabasic biological process, the pesticide may be of health concern by inhalation near herbicide spraying at a concentration 25 times the adverse transcription concentration in the sprayed microdroplets

274

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

OpenAIRE

O objetivo deste trabalho foi avaliar, por meio de curvas de dose-resposta, a ocorrência de biótipos resistentes ao herbicida glyphosate em populações de Conyza canadensis e C. bonariensis, bem como propor tratamentos alternativos para esses biótipos. Os experimentos foram realizados em casa de vegetação, utilizando-se três populações de cada espécie: duas com suspeita de resistência ao herbicida glyphosate, coletadas em pomares de laranja localizados em duas regiões diferentes d...

Moreira, M. S.; Nicolai, M.; Carvalho, S. J. P.; Christoffoleti, P. J.

2007-01-01

275

Selectivity of glyphosate tank mixtures for RR soybean Seletividade de glyphosate em misturas em tanque para soja RR  

OpenAIRE

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 cultivati...

Alonso, D. G.; Constantin, J.; Oliveira Jr, R. S.; Arantes, J. G. Z.; Cavalieri, S. D.; Santos, G.; Rios, F. A.; Franchini, L. H. M.

2011-01-01

276

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

OpenAIRE

O amarelecimento da soja Roundup Ready após aplicação do glyphosate pode estar associado à deficiência momentânea de manganês. Por isso, com a hipótese de que soja tolerante ao glyphosate necessitaria de uma adição suplementar de manganês, o objetivo deste trabalho foi avaliar diferentes manejos na aplicação foliar de manganês sobre alguns parâmetros da soja. Foram desenvolvidos dois experimentos, um no município de Taquaruçú do Sul e outro em Boa Vista das Missões, RS, no ...

Claudir José Basso; Antônio Luis Santi; Fabiane Pinto Lamego; Eduardo Girotto

2011-01-01

277

Pisolithus sp. tolerance to glyphosate and isoxaflutole in vitro / Tolerância de pisolithus sp. a glyphosate e isoxaflutole in vitro  

Scientific Electronic Library Online (English)

Full Text Available Os fungos ectomicorrízicos possuem tolerância diferenciada aos herbicidas e podem promover a sobrevivência e crescimento das plantas de eucalipto. O objetivo deste trabalho foi avaliar a tolerância de isolados do fungo ectomicorrízico . Pisolithus sp. aos herbicidas glyphosate e isoxaflutole. Os iso [...] lados avaliados foram D3, D16, D17, Pt24 e UFVJM04 e as concentrações de glyphosate no meio líquido, de 0, 32, 63, 127 e 254 mg L-1, enquanto no meio sólido, de 0, 32, 63, 127, 254, 507 e 1.014 mg L-1. Para o isoxaflutole nos dois meios de cultura, as concentrações foram de: 0, 295, 589, 1.178 e 2.355 mg L-1. Os ensaios foram independentes para cada herbicida e tipo de meio de cultura. A tolerância dos isolados foi dependente do herbicida e da sua concentração em cada meio. O Pt24 foi o mais tolerante ao glyphosate e o UFVJM04, ao isoxaflutole. O glyphosate foi mais tóxico aos isolados de Pisolithus sp. do que o isoxaflutole. Abstract in english 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.

Mayara Cristina Silva, Fernandes; Lidiomar Soares da, Costa; Paulo Henrique, Grazziotti; Danielle Cristina Fonseca Santos, Grazziotti; José Barbosa dos, Santos; Márcio José, Rossi.

2014-06-01

278

Efeito de adjuvantes adicionados à calda herbicida contendo glyphosate Effect of adjuvants added to herbicide spray containing glyphosate  

OpenAIRE

Tentativas de aumentar a fitotoxicidade do herbicida glyphosate através da adição de ácido e/ ou de sulfato de amônio à calda tem sido promissoras. A adição dessas substâncias otimiza as propriedades químicas da calda herbicida, superando efeitos negativos do pH elevado e de ions nela presentes. O objetivo desse trabalho foi investigar o efeito da adição de ácido sulfúrico e/ou de sulfato de amônio à calda herbicida, sobre a eficiência do glyphosate misturado em diluente com ...

Leandro Vargas; Fleck, Nilson G.; Da Cunha, Marcos M.; Vidal, Ribas A.

1997-01-01

279

Alteration of plant physiology by glyphosate and its by-product aminomethylphosphonic acid: an overview.  

Science.gov (United States)

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. PMID:25039071

Gomes, Marcelo P; Smedbol, Elise; Chalifour, Annie; Hénault-Ethier, Louise; Labrecque, Michel; Lepage, Laurent; Lucotte, Marc; Juneau, Philippe

2014-09-01

280

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

International Nuclear Information System (INIS)

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.

281

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

282

Novel reduction of mercury (II) by mercury-sensitive dissimilatory metal reducing bacteria.  

Science.gov (United States)

The dissimilatory metal reducing bacterium (DMRB) Shewanella oneidensis MR-1 reduces ionic mercury (Hg[II]) to elemental mercury (Hg[0]) by an activity not related to the MerA mercuric reductase. In S. oneidensis, this activity is constitutive and effective at Hg(II) concentrations too low to induce mer operon functions. Reduction of Hg(II) by MR-1 required the presence of electron donors and electron acceptors. Reduction occurred with oxygen or fumarate, but had the highest rate when ferric oxyhydroxide was used as a terminal electron acceptor. Geobacter sulfurreducens PCA and Geobacter metallireducens GS-15 reduced Hg(II) to Hg(0) with activity comparable to MR-1; however, neither the DMRB Anaeromyxobacter dehalogenans 2CP-C nor the nitrate reducer Pseudomonas stutzeri OX-1 reduced Hg(II) during growth. This discovery of constitutive mercury reduction among anaerobes has implications to the mobilization of mercury and production of methylmercury in anoxic environments. PMID:17144297

Wiatrowski, Heather A; Ward, Paula Marie; Barkay, Tamar

2006-11-01

283

Degradation of the Phosphonate Herbicide Glyphosate by Arthrobacter atrocyaneus ATCC 13752  

OpenAIRE

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...

Pipke, Ru?diger; Amrhein, Nikolaus

1988-01-01

284

Differential Effects of Glyphosate and Roundup on Human Placental Cells and Aromatase  

OpenAIRE

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...

Richard, Sophie; Moslemi, Safa; Sipahutar, Herbert; Benachour, Nora; Seralini, Gilles-eric

2005-01-01

285

Glyphosate detection with ammonium nitrate and humic acids as potential interfering substances by pulsed voltammetry technique  

OpenAIRE

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...

Marti?nez Gil, Pablo; Laguarda Miro?, Nicola?s; Soto Camino, Juan; Masot Peris, Rafael

2013-01-01

286

A naturally occurring novel allele of Escherichia coli outer membrane protein A reduces sensitivity to bacteriophage.  

Science.gov (United States)

A novel Escherichia coli outer membrane protein A (OmpA) was discovered through a proteomic investigation of cell surface proteins. DNA polymorphisms were localized to regions encoding the protein's surface-exposed loops which are known phage receptor sites. Bacteriophage sensitivity testing indicated an association between bacteriophage resistance and isolates having the novel ompA allele. PMID:16980421

Power, Michelle L; Ferrari, Belinda C; Littlefield-Wyer, Jane; Gordon, David M; Slade, Martin B; Veal, Duncan A

2006-12-01

287

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)

Full Text Available A utilização intensiva do glyphosate nas lavouras de soja Roundup Ready® (RR no Rio Grande do Sul (RS, nos últimos anos, pode ter selecionado biótipos de leiteira (Euphorbia heterophylla resistentes ao herbicida. Esse cenário dificultará ainda mais o manejo da espécie, já que permanecem indícios da presença de biótipos resistentes também em herbicidas inibidores da acetolactato sintase (ALS. Assim, os objetivos deste trabalho foram avaliar a sensibilidade da leiteira a herbicidas inibidores da ALS e ao glyphosate, verificar a distribuição dos biótipos resistentes no RS e determinar os principais fatores agronômicos associados a falhas de controle. Para isso, amostras de sementes de plantas de leiteira foram coletadas em lavouras de soja RR localizadas em 56 municípios do Estado do RS. Por ocasião das coletas, os agricultores responderam a questionário que abordava o manejo das plantas daninhas na área. Usando-se as sementes coletadas, foram conduzidos dois experimentos em casa de vegetação: no primeiro, avaliou-se a resposta de 86 biótipos ao herbicida glyphosate, aplicado na dose de 2.160 g e.a. ha-1; e, no segundo, a resposta de 73 biótipos ao herbicida imazethapyr, aplicado na dose de 200 g i.a. ha-1. Os resultados obtidos evidenciam que todos os biótipos de leiteira avaliados são suscetíveis ao glyphosate, porém existem biótipos resistentes aos inibidores da ALS. As respostas do questionário indicam que práticas de manejo como uso de subdoses e/ou utilização intensiva do glyphosate e a ausência de rotação de culturas favorecem falhas no controle de leiteira pelo herbicida glyphosate em soja.The intensive use of glyphosate in Roundup Ready® (RR soybean fields in Rio Grande do Sul (RS, in recent years may have selected wild poinsettia (Euphorbia heterophylla biotypes resistant to the herbicide. This scenario will further complicate the management of this species, since evidence remains of the presence of 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.

L. Vargas

2013-06-01

288

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  

Scientific Electronic Library Online (English)

Full Text Available A utilização intensiva do glyphosate nas lavouras de soja Roundup Ready® (RR) no Rio Grande do Sul (RS), nos últimos anos, pode ter selecionado biótipos de leiteira (Euphorbia heterophylla) resistentes ao herbicida. Esse cenário dificultará ainda mais o manejo da espécie, já que permanecem indícios [...] da presença de biótipos resistentes também em herbicidas inibidores da acetolactato sintase (ALS). Assim, os objetivos deste trabalho foram avaliar a sensibilidade da leiteira a herbicidas inibidores da ALS e ao glyphosate, verificar a distribuição dos biótipos resistentes no RS e determinar os principais fatores agronômicos associados a falhas de controle. Para isso, amostras de sementes de plantas de leiteira foram coletadas em lavouras de soja RR localizadas em 56 municípios do Estado do RS. Por ocasião das coletas, os agricultores responderam a questionário que abordava o manejo das plantas daninhas na área. Usando-se as sementes coletadas, foram conduzidos dois experimentos em casa de vegetação: no primeiro, avaliou-se a resposta de 86 biótipos ao herbicida glyphosate, aplicado na dose de 2.160 g e.a. ha-1; e, no segundo, a resposta de 73 biótipos ao herbicida imazethapyr, aplicado na dose de 200 g i.a. ha-1. Os resultados obtidos evidenciam que todos os biótipos de leiteira avaliados são suscetíveis ao glyphosate, porém existem biótipos resistentes aos inibidores da ALS. As respostas do questionário indicam que práticas de manejo como uso de subdoses e/ou utilização intensiva do glyphosate e a ausência de rotação de culturas favorecem falhas no controle de leiteira pelo herbicida glyphosate em soja. Abstract in english The intensive use of glyphosate in Roundup Ready® (RR) soybean fields in Rio Grande do Sul (RS), in recent years may have selected wild poinsettia (Euphorbia heterophylla) biotypes resistant to the herbicide. This scenario will further complicate the management of this species, since evidence remain [...] s of the presence of 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.

L., Vargas; M.A., Nohatto; D., Agostinetto; M.A., Bianchi; J.M., Paula; E., Polidoro; R.E., Toledo.

2013-06-01

289

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...

290

Glyphosate-tolerance mechanism in Italian ryegrass (Lolium multiflorum) from Mississippi  

Science.gov (United States)

A 3-fold glyphosate tolerance was identified in two Italian ryegrass populations, T1 and T2, from Mississippi. Laboratory experiments were conducted to characterize the mechanism of glyphosate tolerance in these populations. The T1 population absorbed less 14C-glyphosate (43% of applied) compared to...

291

IDENTIFCATION OF GLYPHOSATE-RESISTANT ITALIAN RYEGRASS (LOLIUM MULTIFLORUM) IN OREGON  

Science.gov (United States)

A suspected glyphosate-resistant Italian ryegrass biotype was collected from a filbert orchard near Portland, OR, where glyphosate was applied multiple times per year for about 15 yr. Greenhouse studies were conducted to determine if this biotype was glyphosate resistant. The plants were sprayed wit...

292

Manejo de capim pé-de-galinha em lavouras de soja transgênica resistente ao glifosato / Management of goose grass on transgenic soybean, resistant to glyphosate  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar a resistência de capim pé-de-galinha (Eleusine indica) ao glifosato, em lavouras de soja transgênica; avaliar o efeito de aplicações de glifosato em diferentes estádios de desenvolvimento; identificar práticas agronômicas associadas à seleção de biótipos resiste [...] ntes; e avaliar a eficiência dos herbicidas cletodim, fluazifope-P-butílico, clomazona, glufosinato de amônio e glifosato nas plantas resistentes. Plantas escapes ao tratamento com glifosato foram coletadas em 24 propriedades, no Rio Grande do Sul. As plantas foram cultivadas em casa de vegetação, tendo-se avaliado a sua resistência ao glifosato. Os acessos resistentes foram selecionados e avaliados quanto ao efeito da aplicação do glifosato em diferentes estádios de crescimento e quanto à sensibilidade aos herbicidas. Foi aplicado um questionário aos produtores para identificação das práticas agronômicas associadas às falhas no controle. O controle de E. indica pelo glifosato é mais efetivo com a aplicação em estádios iniciais de desenvolvimento. Práticas agronômicas, como uso contínuo de baixas doses do herbicida, aplicação em estádios de desenvolvimento avançados das plantas daninhas (mais de um afilho) e a ausência de rotação de culturas foram relacionadas às falhas de controle observadas. Os herbicidas cletodim, fluazifope-P-butílico e glufosinato de amônio são alternativas eficientes para o controle de E. indica. Abstract in english The objective of this work was to evaluate the resistance of goose grass (Eleusine indica) to glyphosate application in transgenic soybean crops; evaluate the effect of glyphosate applications in different growth stages; identify the main agronomic practices associated with the selection of resistan [...] t biotypes; and evaluate the effect of the herbicides clethodim, fluazifop-p-butyl, clomazone, glufosinate ammonium, and glyphosate on resistant plants. Plants that survived glyphosate application were collected on 24 properties in the state of Rio Grande do Sul, Brazil. Plants were grown in greenhouse and their resistance to glyphosate was evaluated. The resistant accessions were selected and evaluated as to the effect of glyphosate application on different growth stages and to their sensitivity to the herbicides. A questionnaire was given to producers in order to identify agronomic practices associated with control failures. The control of E. indica by glyphosate is more effective at initial growth stages. Agronomic practices, such as continued use of low doses of glyphosate, application on advanced weed growth stages (more than one tiller), and absence of crop rotation were related to the observed control failures. The herbicides clethodim, fluazifop-p-butyl, and glufosinate ammonium are efficient alternatives to control E. indica.

André da Rosa, Ulguim; Leandro, Vargas; Dirceu, Agostinetto; Taísa Dal, Magro; Nixon da Rosa, Westendorff; Marcelo Timm, Holz.

2013-01-01

293

Deposição de glyphosate aplicado para controle de plantas daninhas em soja transgênica / Glyphosate deposition for weed control in transgenic soybean  

Scientific Electronic Library Online (English)

Full Text Available Inúmeros fatores estão envolvidos na tecnologia de aplicação de um herbicida, sendo a deposição correta fundamental para que o produto possa expressar sua eficiência. Com o objetivo de avaliar a deposição de uma solução traçante constituída de glyphosate Roundup Ready (0,96 kg e.a. ha-1) + corante F [...] DC-1 (1.500 ppm), foi conduzido um experimento em área semeada com soja transgênica e infestada com amendoim-bravo (Euphorbia heterophylla), localizada em Londrina-PR. As aplicações foram efetuadas em diferentes estádios de desenvolvimento da cultura, correspondendo a 17, 24, 31, 38 e 45 dias após a emergência da soja. Os alvos, plantas de soja, amendoim-bravo e placas na superfície do solo (linha e entrelinha), foram coletados após pulverização, e a solução traçante foi nestes depositada, posteriormente recuperada através de lavagem com agitação em água destilada. As amostras das soluções recuperadas foram submetidas à análise, utilizando-se procedimentos espectrofotométricos, e os resultados de absorbância convertidos para concentração em µL cm-2 e µL por planta. As freqüências acumuladas dos dados originais de depósito foram adequadamente ajustadas segundo modelo de Gompertz, apresentando elevada precisão (R² > 0,95). Os resultados indicaram que o depósito da calda de pulverização nas plantas de soja e amendoim-bravo reduziu progressivamente com o desenvolvimento da cultura e infestação, sugerindo que a maior garantia de eficiência de controle pode ser conseguida com aplicações precoces. Abstract in english Several factors are involved in herbicide application technology, with correct deposition being essential to ensure product efficacy. To evaluate the deposition of a glyphosate tracer solution (RR) with an FDC-1 dye, an experiment was carried out in a transgenic soybean cultivated area, infested wit [...] h wild poinsettia (Euphorbia heterophylla). Applications were carried out at different crop development stages, corresponding to 17; 24; 31; 38 and 45 days after soybean emergence. The targets, soybean plants, wild poinsettias, and Petri dishes on the soil surface, were collected after spraying and the tracer solution was later recovered by washing and stirring in distilled water. Samples of recovered solutions were submitted to spectrophotometer analysis, and the absorption data were converted in µL cm-2 and µL per plant. The accumulated frequencies of the original deposit data were adequately adjusted to the Gompertz model, showing high precision (R² > 0.95). The results showed that the spraying solution deposition on soybean plants and wild poinsettia reduced progressively with crop development and weed infestation, suggesting that control efficiency can be obtained with early applications.

D.L.P., Gazziero; C.D.G., Maciel; R.T., Souza; E.D., Velini; C.E.C., Prete; W., Oliveira Neto.

294

Gastric Bypass Surgery Reduces Plasma Ceramide Subspecies and Improves Insulin Sensitivity in Severely Obese Patients  

OpenAIRE

Bariatric surgery is associated with near immediate remission of type 2 diabetes and hyperlipidemia. The mechanisms underlying restoration of normal glucose tolerance post-operatively are poorly understood. Herein, we examined the effect of Roux-en-Y gastric bypass surgery (RYGB) on weight loss, insulin sensitivity, plasma ceramides, pro-inflammatory markers, and cardiovascular risk factors before and at 3 and 6 months after surgery. Thirteen patients (10 female; age 48.5±2.7 yrs; BMI, 47.4?...

Huang, H.; Kasumov, T.; Gatmaitan, P.; Heneghan, H. M.; Kashyap, S. R.; Schauer, P. R.; Brethauer, S. A.; Kirwan, J. P.

2011-01-01

295

Greater Intima–Media Thickness in the Carotid Bulb Is Associated With Reduced Baroreflex Sensitivity  

OpenAIRE

The aim of this study was to evaluate the association between resting baroreflex sensitivity (BRS) and carotid intima–media thickness (IMT), a putative marker of sub-clinical atherosclerosis. Participants were 64 men and 18 women (median age, 57 years; range, 40 to 70 years), who did not have a previous history of coronary artery disease or treatment for hypertension. Resting BRS was measured during a 9-min baseline period using the noninvasive sequence technique; carotid IMT was subsequent...

Gianaros, Peter J.; Jennings, J. Richard; Olafsson, G. Benedikt; Steptoe, Andrew; Sutton-tyrrell, Kim; Muldoon, Matthew F.; Manuck, Stephen B.

2002-01-01

296

Effect of reducing groundwater on the retardation of redox-sensitive radionuclides  

OpenAIRE

Abstract Laboratory batch sorption experiments were used to investigate variations in the retardation behavior of redox-sensitive radionuclides. Water-rock compositions were designed to simulate subsurface conditions at the Nevada Test Site (NTS), where a suite of radionuclides were deposited as a result of underground nuclear testing. Experimental redox conditions were controlled by varying the oxygen content inside an enclosed glove box and by adding reductants into the testing solutions. U...

Tp, Rose; Zavarin M; Qh, Hu

2008-01-01

297

Technical Note: Method of Morris effectively reduces the computational demands of global sensitivity analysis for distributed watershed models  

Science.gov (United States)

The increase in spatially distributed hydrologic modeling warrants a corresponding increase in diagnostic methods capable of analyzing complex models with large numbers of parameters. Sobol' sensitivity analysis has proven to be a valuable tool for diagnostic analyses of hydrologic models. However, for many spatially distributed models, the Sobol' method requires a prohibitive number of model evaluations to reliably decompose output variance across the full set of parameters. We investigate the potential of the method of Morris, a screening-based sensitivity approach, to provide results sufficiently similar to those of the Sobol' method at a greatly reduced computational expense. The methods are benchmarked on the Hydrology Laboratory Research Distributed Hydrologic Model (HL-RDHM) over a six-month period in the Blue River watershed, Oklahoma, USA. The Sobol' method required over six million model evaluations to ensure reliable sensitivity indices, corresponding to more than 30 000 computing hours and roughly 180 gigabytes of storage space. We find that the method of Morris is able to correctly screen the most and least sensitive parameters with 300 times fewer model evaluations, requiring only 100 computing hours and 1 gigabyte of storage space. The method of Morris proves to be a promising diagnostic approach for global sensitivity analysis of highly parameterized, spatially distributed hydrologic models.

Herman, J. D.; Kollat, J. B.; Reed, P. M.; Wagener, T.

2013-07-01

298

Technical Note: Method of Morris effectively reduces the computational demands of global sensitivity analysis for distributed watershed models  

Directory of Open Access Journals (Sweden)

Full Text Available The increase in spatially distributed hydrologic modeling warrants a corresponding increase in diagnostic methods capable of analyzing complex models with large numbers of parameters. Sobol' sensitivity analysis has proven to be a valuable tool for diagnostic analyses of hydrologic models. However, for many spatially distributed models, the Sobol' method requires a prohibitive number of model evaluations to reliably decompose output variance across the full set of parameters. We investigate the potential of the method of Morris, a screening-based sensitivity approach, to provide results sufficiently similar to those of the Sobol' method at a greatly reduced computational expense. The methods are benchmarked on the Hydrology Laboratory Research Distributed Hydrologic Model (HL-RDHM over a six-month period in the Blue River watershed, Oklahoma, USA. The Sobol' method required over six million model evaluations to ensure reliable sensitivity indices, corresponding to more than 30 000 computing hours and roughly 180 gigabytes of storage space. We find that the method of Morris is able to correctly screen the most and least sensitive parameters with 300 times fewer model evaluations, requiring only 100 computing hours and 1 gigabyte of storage space. The method of Morris proves to be a promising diagnostic approach for global sensitivity analysis of highly parameterized, spatially distributed hydrologic models.

J. D. Herman

2013-07-01

299

Technical note: Method of Morris effectively reduces the computational demands of global sensitivity analysis for distributed watershed models  

Directory of Open Access Journals (Sweden)

Full Text Available The increase in spatially distributed hydrologic modeling warrants a corresponding increase in diagnostic methods capable of analyzing complex models with large numbers of parameters. Sobol' sensitivity analysis has proven to be a valuable tool for diagnostic analyses of hydrologic models. However, for many spatially distributed models, the Sobol' method requires a prohibitive number of model evaluations to reliably decompose output variance across the full set of parameters. We investigate the potential of the method of Morris, a screening-based sensitivity approach, to provide results sufficiently similar to those of the Sobol' method at a greatly reduced computational expense. The methods are benchmarked on the Hydrology Laboratory Research Distributed Hydrologic Model (HL-RDHM model over a six-month period in the Blue River Watershed, Oklahoma, USA. The Sobol' method required over six million model evaluations to ensure reliable sensitivity indices, corresponding to more than 30 000 computing hours and roughly 180 gigabytes of storage space. We find that the method of Morris is able to correctly identify sensitive and insensitive parameters with 300 times fewer model evaluations, requiring only 100 computing hours and 1 gigabyte of storage space. Method of Morris proves to be a promising diagnostic approach for global sensitivity analysis of highly parameterized, spatially distributed hydrologic models.

J. D. Herman

2013-04-01

300

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 esta [...] nde 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. Abstract in english 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 g [...] rowing 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 variables studied. The results showed that the control treatment (when glyphosate was applided six hours befores sowing) was statistically superior to the other treatments in stand formation, plant height, root length and plant/root dry matter.

C.A.C., Crusciol; E.V., Lima; M., Andreotti; M.A., Schiocchet.

2002-04-01

301

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)

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 variables studied. The results showed that the control treatment (when glyphosate was applided six hours befores sowing was statistically superior to the other treatments in stand formation, plant height, root length and plant/root dry matter.

C.A.C. Crusciol

2002-04-01

302

Subacute toxicity of copper and glyphosate and their interaction to earthworm (Eisenia fetida)  

International Nuclear Information System (INIS)

Glyphosate (GPS) and copper (Cu) are common pollutants in soils, and commonly co-exist. Due to the chemical structure of GPS, it can form complexes of heavy metals and interface their bioavailability in soil environment. In order to explore the interactions between GPS and Cu, subacute toxicity tests of Cu and GPS on soil invertebrate earthworms (Eisenia fetida) were conducted. The relative weight loss and whole-worm metal burdens increased significantly with the increasing exposure concentration of Cu, while the toxicity of GPS was insignificant. The joint toxicity data showed that the relative weight loss and the uptake of Cu, as well as the superoxide dismutase, catalase and malondialdehyde activities, were significantly alleviated in the present of GPS, which indicated that GPS could reduce the toxicity and bioavailability of Cu in the soil because of its strong chelating effects. Highlights: •Cu markedly increased the weight loss ratio of earthworm. •Cu decreased the cocoon production of earthworm. •The toxicity of GPS on earthworm was insignificant. •The presence of GPS could reduce the toxicity of Cu on earthworm. -- The presence of glyphosate could reduce the toxicity and bioavailability of Cu in the soil because of its strong chelating effects

303

Weed Control, Environmental Impact and Profitability of Weed Management Strategies in Glyphosate-Resistant Corn  

Directory of Open Access Journals (Sweden)

Full Text Available Eleven field trials were conducted over a three-year period (2006-2008 at three locations in southwestern Ontario, Canada to evaluate the effect of various weed management strategies in glyphosate-tolerant corn on weed control, crop injury, corn yield, environmental impact and profit margin. No visible injury resulted from the herbicide treatments evaluated. Overall, the effect of all factors assessed were location specific. By 56 days after treatment, depending on location, glyphosate applied at the 7 - 8 leaf stage (LPOST, preemergence (PRE herbicides followed by (fb glyphosate LPOST and sequential glyphosate applications (EPOST (3 - 4 leaf stage followed by LPOST provided more consistent control of annual broadleaf weeds and annual grasses compared to glyphosate applied alone EPOST. Weed control at 56 days after treatment was lower when glyphosate was applied alone LPOST compared to sequential applications of glyphosate or PRE herbicides fb glyphosate. There were no differences in corn yield among the sequential programs evaluated; however, a yield benefit was found when a sequential program was used compared to glyphosate applied alone LPOST. Among the sequential programs the lowest environmental impact was isoxaflutole/atrazine fb glyphosate. The lowest profit margins were associated with atrazine, S-metolachlor/atrazine/benoxacor, dicamba/atrazine and glyphosate LPOST treatments compared to all other treatments. Overall, profit margins tended to be somewhat higher for treatments that included glyphosate applications. Based on these results, the most efficacious and profitable weed management program in corn was a sequential application of glyphosate; however, isoxaflutole/atrazine fb glyphosate was the treatment with the lowest environmental risk while also adding glyphosate stewardship benefits.

Nader Soltani

2012-11-01

304

Structure of foot-and-mouth disease virus mutant 7 polymerases with reduced sensitivity to ribavirin  

OpenAIRE

Passage of poliovirus (PV) or foot-and-mouth disease virus (FMDV) in the presence of ribavirin selected for viruses with decreased sensitivity to R, which included different mutations in their polymerase (3D): G64S located in the finger subdomain in the case of PV and M296I located within loop beta9-alpha11 at the active site in the case of FMDV. To investigate why disparate substitutions were selected in two closely related 3Ds, we constructed FMDVs with a 3D that included either G62S (the e...

Ferrer-orta, Cristina; Sierra Garci?a, Macarena; Higuera, Ignacio La; Agudo, Rube?n; Arias, Armando; Pe?rez-luque, Rosa; Escarmis Homs, Cristina; Domingo, Esteban; Verdaguer, Nuria

2010-01-01

305

Structure of Foot-and-Mouth Disease Virus Mutant Polymerases with Reduced Sensitivity to Ribavirin? †  

OpenAIRE

Passage of poliovirus (PV) or foot-and-mouth disease virus (FMDV) in the presence of ribavirin (R) selected for viruses with decreased sensitivity to R, which included different mutations in their polymerase (3D): G64S located in the finger subdomain in the case of PV and M296I located within loop ?9-?11 at the active site in the case of FMDV. To investigate why disparate substitutions were selected in two closely related 3Ds, we constructed FMDVs with a 3D that included either G62S (the eq...

Ferrer-orta, Cristina; Sierra Garci?a, Macarena; Agudo, Rube?n; Higuera, Ignacio La; Arias, Armando; Pe?rez-luque, Rosa; Escarmis, Cristina; Domingo, Esteban; Verdaguer, Nu?ria

2010-01-01

306

Sensitivity study of reduced models of the activated sludge process, for the purposes of parameter estimation and process optimisation: benchmark process with ASM1 and UCT reduced biological models  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english The problem of derivation and calculation of sensitivity functions for all parameters of the mass balance reduced model of the COST benchmark activated sludge plant is formulated and solved. The sensitivity functions, equations and augmented sensitivity state space models are derived for the cases o [...] f ASM1 and UCT reduced biological models. Matlab software for sensitivity function calculation and sensitivity model simulation is developed. The results are described and discussed. The behaviour of the sensitivity functions is used to determine which parameters of the reduced model need to be estimated in order to fit the reduced model behaviour to the real data for the process behaviour.

S, du Plessis; R, Tzoneva.

307

Replacing Fish Oil with Vegetable Oils in Salmon Feed Increases Hepatic Lipid Accumulation and Reduces Insulin Sensitivity in Mice  

DEFF Research Database (Denmark)

Background: Due to a growing global aquaculture production, fish oil (FO) and fish meal (FM) are partly replaced with vegetable ingredients in aqua feed for Atlantic salmon. These replacements in the feed lead to an altered fatty acid composition in the salmon fillet. We aimed to investigate how these changes affects obesity development and insulin sensitivity in mice eating the salmon. In addition, we wanted to investigate how the background diet affects the antiobesity effect of FO. Results: Western diets (WDs) were produced containing salmon fed either FO (WD-FO), or with partly replacement (80%) of FO with different vegetable oils (VOs); rape seed oil (WDRO), olive oil (WD-OO) or soybean oil (WD-SO). These diets were given to C57BL/6J mice, and mice had higher hepatic lipid accumulation and lower insulin sensitivity when given WD-SO compared with WD-FO. Mice given WD-SO had higher hepatic levels of diacylglycerol (DAG), ceramides and arachidonic acid (AA)-derived oxylipins compared with mice fed WD-FO. In addition, C57BL/6J mice were fed fish oil-enriched diets with different carbohydrate sources, and we observed that sucrose dose-dependently abrogate the antiobesity effect of fish oil. High-GI starch had a stronger effect on reducing the antiobesity effect of FO compared with low-GI starch. Conclusions: In summary, our results demonstrate that the background diet affects the antiobesity effect of FO and that replacement of FO with SO in aqua feed increased hepatic lipid accumulation and reduces insulin sensitivity. Elevated hepatic levels of DAG, ceramides and AA-derived oxylipins might be a link between the observed hepatic lipid accumulation and the reduced insulin sensitivity.

MidtbØ, Lisa Kolden

2013-01-01

308

Momento da chuva após a aplicação e a eficácia dos herbicidas sulfosate e glyphosate aplicados em diferentes formulações Rainfastness and glyphosate and sulfosate efficacy using different formulations  

Directory of Open Access Journals (Sweden)

Full Text Available Com o objetivo de estudar a influência da chuva sobre o desempenho dos herbicidas sulfosate e glyphosate em diferentes formulações, foram conduzidos dois experimentos, um no inverno de 2000 e outro no verão de 2001, na Fazenda Experimental de Ensino e Pesquisa da Faculdade de Ciências Agrárias e Veterinárias, Campus de Jaboticabal-SP. Os experimentos foram instalados segundo o delineamento experimental de blocos ao acaso, com quatro repetições, no arranjo fatorial de 4x5+1, ou seja, quatro tratamentos de herbicidas, cinco períodos sem chuva após a aplicação e uma testemunha, que não recebeu chuva. As formulações de glyphosate foram: SAqC (1,0 L ha-1, GrDA (0,5 kg ha-1, SAqC Transorb (0,75 L ha-1, mais o sulfosate SAqC (1,09 L ha¹. Os períodos sem chuva após a aplicação foram de 1, 2, 4, 6 e > 48 horas. Os herbicidas foram aplicados em pós-emergência das plantas daninhas, utilizando-se de um pulverizador costal, à pressão constante (mantida por ar comprimido de 30 lbf pol-2. A chuva foi simulada com um sistema de irrigação por aspersão. A lâmina de água variou entre 18 e 19 mm. Em ambas as épocas, a chuva simulada foi prejudicial à ação dos herbicidas, principalmente quando feita nos menores intervalos após a aplicação. Os sintomas de fitointoxicação apareceram mais rapidamente no verão. A formulação Transorb, comercializada como não sendo afetada pela chuva uma hora após a aplicação, não teve o desempenho esperado, tanto no inverno quanto no verão, para períodos de até seis horas sem chuva após a aplicação. O sulfosate apresentou o melhor controle geral das plantas avaliadas, quando se simulou chuva após seis horas, em ambas as épocas. A formulação GrDA foi a mais afetada pela ação da chuva em ambas as épocas.Two field assays were carried out to evaluate the rainfall effects on sulfosate and glyphosate herbicide activity, using different formulations, under two growing seasons (winter and summer. The experiments were conducted at the FCAV/UNESP Experimental Station, Jaboticabel, Brazil, during 2000/01. The formulations were glyphosate SA (1.0 L ha-1, WG (0.5 L ha-1, Transorb (0.75 L ha-1 and sulfosate SA (1.09 L ha-1. In the field, all the trials were arranged in a randomized block experimental design, with four replications. The treatments were arranged in factorial design 5 x 4 + 1 factors, with five periods between the herbicide spraying and the rain incidence (1, 2, 4, 6 and > 48 h, plus one control treatment. The herbicide treatments were applied using a back spraying, with six nozzles DG 11002, spaced by 0.5 m, at 30 p.s.i. constant pression. Artificial rain was provided by a top irrigation system raining 18-19 mm during one hour. The artificial rain reduced glyphosate action, mainly in the shorter periods between herbicide application and the rain incidence. The herbicide symptoms appeared quicker in the summer trials. The Transorb formulation (advertised as not affected by rain one hour after spraying had the phytointoxication symptoms reduced by the rain up to six hours after spraying, both in the summer and winter. The herbicide sulfosate promoted better control when the rain occurred six hours after spraying, in both seasons.

A.F.F. Pedrinho Júnior

2002-04-01

309

Momento da chuva após a aplicação e a eficácia dos herbicidas sulfosate e glyphosate aplicados em diferentes formulações / Rainfastness and glyphosate and sulfosate efficacy using different formulations  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Com o objetivo de estudar a influência da chuva sobre o desempenho dos herbicidas sulfosate e glyphosate em diferentes formulações, foram conduzidos dois experimentos, um no inverno de 2000 e outro no verão de 2001, na Fazenda Experimental de Ensino e Pesquisa da Faculdade de Ciências Agrárias e Vet [...] erinárias, Campus de Jaboticabal-SP. Os experimentos foram instalados segundo o delineamento experimental de blocos ao acaso, com quatro repetições, no arranjo fatorial de 4x5+1, ou seja, quatro tratamentos de herbicidas, cinco períodos sem chuva após a aplicação e uma testemunha, que não recebeu chuva. As formulações de glyphosate foram: SAqC (1,0 L ha-1), GrDA (0,5 kg ha-1), SAqC Transorb (0,75 L ha-1), mais o sulfosate SAqC (1,09 L ha¹). Os períodos sem chuva após a aplicação foram de 1, 2, 4, 6 e > 48 horas. Os herbicidas foram aplicados em pós-emergência das plantas daninhas, utilizando-se de um pulverizador costal, à pressão constante (mantida por ar comprimido) de 30 lbf pol-2. A chuva foi simulada com um sistema de irrigação por aspersão. A lâmina de água variou entre 18 e 19 mm. Em ambas as épocas, a chuva simulada foi prejudicial à ação dos herbicidas, principalmente quando feita nos menores intervalos após a aplicação. Os sintomas de fitointoxicação apareceram mais rapidamente no verão. A formulação Transorb, comercializada como não sendo afetada pela chuva uma hora após a aplicação, não teve o desempenho esperado, tanto no inverno quanto no verão, para períodos de até seis horas sem chuva após a aplicação. O sulfosate apresentou o melhor controle geral das plantas avaliadas, quando se simulou chuva após seis horas, em ambas as épocas. A formulação GrDA foi a mais afetada pela ação da chuva em ambas as épocas. Abstract in english Two field assays were carried out to evaluate the rainfall effects on sulfosate and glyphosate herbicide activity, using different formulations, under two growing seasons (winter and summer). The experiments were conducted at the FCAV/UNESP Experimental Station, Jaboticabel, Brazil, during 2000/01. [...] The formulations were glyphosate SA (1.0 L ha-1), WG (0.5 L ha-1), Transorb (0.75 L ha-1) and sulfosate SA (1.09 L ha-1). In the field, all the trials were arranged in a randomized block experimental design, with four replications. The treatments were arranged in factorial design 5 x 4 + 1 factors, with five periods between the herbicide spraying and the rain incidence (1, 2, 4, 6 and > 48 h), plus one control treatment. The herbicide treatments were applied using a back spraying, with six nozzles DG 11002, spaced by 0.5 m, at 30 p.s.i. constant pression. Artificial rain was provided by a top irrigation system raining 18-19 mm during one hour. The artificial rain reduced glyphosate action, mainly in the shorter periods between herbicide application and the rain incidence. The herbicide symptoms appeared quicker in the summer trials. The Transorb formulation (advertised as not affected by rain one hour after spraying) had the phytointoxication symptoms reduced by the rain up to six hours after spraying, both in the summer and winter. The herbicide sulfosate promoted better control when the rain occurred six hours after spraying, in both seasons.

A.F.F., Pedrinho Júnior; G., Martini; G.V., Felici; F.M., Piva; J.C., Durigan.

2002-04-01

310

Adsorção de glifosato sobre solos e minerais Adsorption of glyphosate on soils and minerals  

Directory of Open Access Journals (Sweden)

Full Text Available Glyphosate, an enzyme inhibitor herbicide, has been widely used around the world in agriculture. Dr. John Franz from Monsanto Corporation (USA discovered glyphosate in 1970. It has been showed that glyphosate is strongly adsorbed by inorganic soil components especially aluminium and iron oxides, and the phosphate group is involved in this interaction. The inactivation of glyphosate in soils can last for days or even months depending on soil characteristics. The addition of phosphate from fertilizers can displace glyphosate from the soils and this could be the cause of decreased productivity of some crops.

Luís R. M. Toni

2006-07-01

311

Sensitive and reliable ascorbic acid sensing by lanthanum oxide/reduced graphene oxide nanocomposite.  

Science.gov (United States)

A simple strategy for the detection and estimation of ascorbic acid (AA), using lanthanum oxide-reduced graphene oxide nanocomposite (LO/RGO) on indium tin oxide (ITO) substrate, is reported. LO/RGO displays high catalytic activity toward the oxidation of AA, and the synergism between lanthanum oxide and reduced graphene oxide was attributed to the successful and efficient detection. Detection mechanism and sensing efficacy of LO/RGO nanocomposite are investigated by electrochemical techniques. Chronoamperometric results under optimal conditions show a linear response range from 14 to 100 ?M for AA detection. Commercially available vitamin C tablets were also analyzed using the proposed LO/RGO sensor, and the remarkable recovery percentage (97.64-99.7) shows the potential application in AA detection. PMID:24879601

Mogha, Navin Kumar; Sahu, Vikrant; Sharma, Meenakshi; Sharma, Raj Kishore; Masram, Dhanraj T

2014-10-01

312

Aluminum sulfate significantly reduces the skin test response to common allergens in sensitized patients  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Avoidance of allergens is still recommended as the first and best way to prevent allergic illnesses and their comorbid diseases. Despite a variety of attempts there has been very limited success in the area of environmental control of allergic disease. Our objective was to identify a non-invasive, non-pharmacological method to reduce indoor allergen loads in atopic persons' homes and public environments. We employed a novel in vivo approach to examine the possibility of using aluminum sulfate to control environmental allergens. Methods Fifty skin test reactive patients were simultaneously skin tested with conventional test materials and the actions of the protein/glycoprotein modifier, aluminum sulfate. Common allergens, dog, cat, dust mite, Alternaria, and cockroach were used in the study. Results Skin test reactivity was significantly reduced by the modifier aluminum sulfate. Our studies demonstrate that the effects of histamine were not affected by the presence of aluminum sulfate. In fact, skin test reactivity was reduced independent of whether aluminum sulfate was present in the allergen test material or removed prior to testing, indicating that the allergens had in some way been inactivated. Conclusion Aluminum sulfate was found to reduce the in vivo allergic reaction cascade induced by skin testing with common allergens. The exact mechanism is not clear but appears to involve the alteration of IgE-binding epitopes on the allergen. Our results indicate that it may be possible to diminish the allergenicity of an environment by application of the active agent aluminum sulfate, thus producing environmental control without complete removal of the allergen.

Grier Thomas J

2006-02-01

313

Aluminum sulfate significantly reduces the skin test response to common allergens in sensitized patients  

OpenAIRE

Abstract Background Avoidance of allergens is still recommended as the first and best way to prevent allergic illnesses and their comorbid diseases. Despite a variety of attempts there has been very limited success in the area of environmental control of allergic disease. Our objective was to identify a non-invasive, non-pharmacological method to reduce indoor allergen loads in atopic persons' homes and public environments. We employed a novel in vivo approach to examine the possibility of us...

Grier Thomas J; Smith Scott A; Steven, Smith C.; Justus David E

2006-01-01

314

A highly sensitive assay for spectrofluorimetric determination of reduced glutathione using organic nano-probes  

Science.gov (United States)

In this study, the new nanometer-sized fluorescent particles (1-pyrenemethylamine nanoparticles) have been prepared by reprecipitation method under ultrasonic radiation. These nanoparticles have the potential to overcome problems encountered by organic small molecules by combining the advantages of high photobleaching threshold, high quantum yield, long fluorescence lifetime, good chemical stability, and wide excitation spectral properties. These nanoparticles will be able to be directly used as fluorescent nanoparticles probe without modification. A new fluorimetric method for the determination of reduced glutathione (GSH) has been developed with these nanoparticles. Under optimal conditions, the organic nanoparticles reacted with GSH and o-phthalaldehyde (OPA) to give a highly fluorescent derivative in Na 2CO 3-HCl buffer (pH = 9.0). The fluorescence excitation and emission wavelengths of fluorescent derivative were located at 345 and 400 nm, respectively. The relative fluorescence intensity (RF) was linear in the range of the GSH concentration from 8.0 × 10 -7 to 1.1 × 10 -4 mol l -1. Limit of detection of 7.1 × 10 -8 mol l -1 was achieved for the reduced glutathione. The method was validated and applied to the analysis of three synthetic samples containing reduced glutathione.

Wang, Leyu; Wang, Lun; Xia, Tingting; Bian, Guirong; Dong, Ling; Tang, Zhenxiang; Wang, Fei

2005-09-01

315

Praziquantel sensitivity of Kenyan Schistosoma mansoni isolates and the generation of a laboratory strain with reduced susceptibility to the drug  

Directory of Open Access Journals (Sweden)

Full Text Available Schistosomiasis is a neglected tropical disease caused by blood-dwelling flukes of the genus Schistosoma. While the disease may affect as many as 249 million people, treatment largely relies on a single drug, praziquantel. The near exclusive use of this drug for such a prevalent disease has led to concerns regarding the potential for drug resistance to arise and the effect this would have on affected populations. In this study, we use an in vitro assay of drug sensitivity to test the effect of praziquantel on miracidia hatched from eggs obtained from fecal samples of Kenyan adult car washers and sand harvesters as well as school children. Whereas in a previous study we found the car washers and sand harvesters to harbor Schistosoma mansoni with reduced praziquantel sensitivity, we found no evidence for the presence of such strains in any of the groups tested here. Using miracidia derived from seven car washers to infect snails, we used the shed cercariae to establish a strain of S. mansoni with significantly reduced praziquantel sensitivity in mice. This was achieved within 5 generations by administering increasing doses of praziquantel to the infected mice until the parasites could withstand a normally lethal dose. This result indicates that while the threat of praziquantel resistance may have diminished in the Kenyan populations tested here, there is a strong likelihood it could return if sufficient praziquantel pressure is applied.

Ibrahim N. Mwangi

2014-12-01

316

Praziquantel sensitivity of Kenyan Schistosoma mansoni isolates and the generation of a laboratory strain with reduced susceptibility to the drug.  

Science.gov (United States)

Schistosomiasis is a neglected tropical disease caused by blood-dwelling flukes of the genus Schistosoma. While the disease may affect as many as 249 million people, treatment largely relies on a single drug, praziquantel. The near exclusive use of this drug for such a prevalent disease has led to concerns regarding the potential for drug resistance to arise and the effect this would have on affected populations. In this study, we use an in vitro assay of drug sensitivity to test the effect of praziquantel on miracidia hatched from eggs obtained from fecal samples of Kenyan adult car washers and sand harvesters as well as school children. Whereas in a previous study we found the car washers and sand harvesters to harbor Schistosoma mansoni with reduced praziquantel sensitivity, we found no evidence for the presence of such strains in any of the groups tested here. Using miracidia derived from seven car washers to infect snails, we used the shed cercariae to establish a strain of S. mansoni with significantly reduced praziquantel sensitivity in mice. This was achieved within 5 generations by administering increasing doses of praziquantel to the infected mice until the parasites could withstand a normally lethal dose. This result indicates that while the threat of praziquantel resistance may have diminished in the Kenyan populations tested here, there is a strong likelihood it could return if sufficient praziquantel pressure is applied. PMID:25516840

Mwangi, Ibrahim N; Sanchez, Melissa C; Mkoji, Gerald M; Agola, Lelo E; Runo, Steven M; Cupit, Pauline M; Cunningham, Charles

2014-12-01

317

Doubly imprinted polymer nanofilm-modified electrochemical sensor for ultra-trace simultaneous analysis of glyphosate and glufosinate.  

Science.gov (United States)

A rapid, selective, and sensitive double-template imprinted polymer nanofilm-modified pencil graphite electrode was fabricated for the simultaneous analysis of phosphorus-containing amino acid-type herbicides (glyphosate and glufosinate) in soil and human serum samples. Since both herbicides respond overlapped oxidation peaks and only glyphosate is prone to nitrosation, n-nitroso glyphosate and glufosinate were used as templates for obtaining the well-resolved quantitative differential pulse anodic stripping voltammetric peaks on the proposed sensor. Toward sensor fabrication, a nano-structured polymer film was first grown directly on the electrode via initial immobilization of gold nanoparticles at its surface. This was followed by linking of monomeric (N-methacryloyl-l-cysteine) molecules through S-Au bonds. Subsequently, these molecules were subjected to free radical polymerization, in the presence of templates, cross linker, initiator, and multiwalled carbon nanotubes as pre-polymer mixture. The modified sensor observed wide linear ranges (3.98-176.23 ng mL(-1) and 0.54-3.96 ng mL(-1)) of simultaneous analysis with detection limits as low as 0.35 and 0.19 ng mL(-1) (S/N=3) for glyphosate and glufosinate, respectively, in aqueous samples. The respective oxidation peak potentials of both analytes were found to be substantially apart by 265 mV. This enabled the simultaneous determination of one target in the presence of other, without any cross reactivity, interferences, and false-positives, in real samples. PMID:24704689

Prasad, Bhim Bali; Jauhari, Darshika; Tiwari, Mahavir Prasad

2014-09-15

318

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)

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 (?g(1-1/) (n)  mL(1/) (n) ( ) g(-1) ) for aminomethylphosphonic acid, showing the broad range of applicability of the proposed method. PMID:25137606

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

2014-11-01

319

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

Directory of Open Access Journals (Sweden)

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 Grande do Sul. Control and dry weight were evaluated. The results indicated that the wild poinsettia biotypes are susceptible to glyphosate.

L Vargas

2011-01-01

320

Deriva simulada do glyphosate em cultivares de café Acaiá e Catucaí / Simulated glyphosate drift on Acaiá and Catucaí coffee cultivars  

Scientific Electronic Library Online (English)

Full Text Available O objetivo desta pesquisa foi avaliar os efeitos da deriva simulada de glyphosate sobre o crescimento inicial de dois cultivares de café de crescimento distinto. Utilizou-se o delineamento em blocos casualizados com quatro repetições, sendo os tratamentos distribuídos em esquema fatorial 2x5. No pri [...] meiro fator foram alocados os cultivares e, no segundo, as subdoses do glyphosate (0, 57,6; 115,2; 230,4; e 460,8 g ha-1). No dia da aplicação e também aos 45 e 120 dias após aplicação (DAA), avaliaram-se a altura, a área foliar, o diâmetro do caule, o número de ramos plagiotrópicos e de folhas; aos 10, 45 e 120 DAA foram avaliados os sintomas de intoxicação nas plantas e, aos 120 DAA, o acúmulo de massa seca de caule, folhas e raízes. Os sintomas de intoxicação nas plantas de café causados pelo glyphosate foram caracterizados por clorose e estreitamento do limbo foliar nos dois cultivares estudados. Todavia, sintomas mais severos foram verificados no cultivar Acaiá a partir de 10 DAA, como necrose de folhas mais novas da parte mediana da planta. Conclui-se que o cultivar Acaiá é menos tolerante ao glyphosate, quando comparado ao Catucaí, pois apresentou menor crescimento que o Catucaí quando submetidos ao tratamento com o herbicida, ou seja, pode ocorrer tolerância diferencial entre cultivares de crescimento distinto. Abstract in english This study aimed to evaluate the effects of simulated glyphosate drift on the growth of two cultivars with distinct growing patterns. The experiment was arranged in a randomized block design, with four repetitions, and the treatments were distributed in a factorial scheme 2x5, with two cultivars in [...] the first factor and the glyphosate subdoses (0, 57.6; 115.2; 230.4 and 460.8 g ha?1) in the second factor. On the day glyphosate was applied and at 45 and 120 days after application (DAA), height, leaf area, stem diameter, and number of plagiotropic branches and leaves were evaluated; at 10, 45 and 120 DAA, plant intoxication symptoms were visually evaluated and at 120 DAA, dry mass accumulation of the stem, leaves, and roots was evaluated. The intoxication symptoms of the coffee plants caused by glyphosate were characterized by chlorosis and leaf narrowing in the two cultivars studied. However, more severe symptoms were verified in the Acaiá cultivars from 10 DAA on, such as necrosis of younger leaves in the median part of the plant. It was concluded that Acaiá cultivar is less tolerant to glyphosate than Catucaí cultivar, since it showed lower growth when submitted to herbicide treatment, i.e., tolerance can vary between cultivars with distinct growing patterns.

A.C., França; F.P., Carvalho; C.M.T., Fialho; L., D' Antonino; A.A., Silva; J.B., Santos; L.R., Ferreira.

2013-06-01

321

Absorção, translocação e exsudação radicular de glyphosate em clones de eucalipto: clones Absorption, translocation and radicular glyphosate exudation in Eucalyptus sp  

OpenAIRE

Objetivou-se com este trabalho avaliar a absorção, translocação e exsudação radicular de glyphosate por dois clones de eucalipto: 2277 e 531. O 14C-glyphosate foi aplicado na concentração de 1.440 g ha-1, distribuída uniformemente no terceiro e no quarto limbo foliar a partir do ápice caulinar, com radioatividade aproximada de 0,030 ?Ci. A absorção, translocação e exsudação radicular foram avaliadas pela radioatividade do 14C-glyphosate nos diferentes tecidos da planta, b...

Machado, A. F. L.; Ferreira, L. R.; Santos, L. D. T.; Santos, J. B.; Ferreira, F. A.; Viana, R. G.

2009-01-01

322

Dinâmica do banco de sementes em áreas com aplicação freqüente do herbicida glyphosate Seed bank dynamics in areas with frequent glyphosate application  

OpenAIRE

Embora o herbicida glyphosate seja considerado não-seletivo, várias espécies de plantas daninhas apresentam certo grau de tolerância às doses recomendadas. No Brasil, já existem relatos de seleção de espécies de plantas daninhas tolerantes ao glyphosate em áreas com o uso intensivo deste herbicida. Assim, o objetivo desta pesquisa foi avaliar a influência da aplicação repetitiva do herbicida glyphosate sobre a dinâmica do banco de sementes das plantas daninhas tolerantes: Commel...

Monquero, P. A.; Christoffoleti, P. J.

2003-01-01

323

Effect of reduced oxygen BWR water chemistry on propensity for intergranular stress corrosion cracking in sensitized austenitic stainless steel  

International Nuclear Information System (INIS)

In-plant studies in fast flowing full temperature primary reactor water on propensity for intergranular corrosion cracking (IGSCC) in sensitized type 304SS have been performed in the Ringhals 1 BWR. The material was tested by CERT technique using notched specimens. Tests to be presented include approximately 100 CERT specimens. As an aid in test evaluation electrochemical potential measurements were run simultaneously to the CERT tests. Experiments were run both in presently current reactor water chemistry with 200-400 ppb O2, and at three differnet water chemistries of reduced oxygen concentration attained by adding hydrogen to the reactor feed water. IGSCC crack propagation rate decreases with decreasing reactor water oxygen concentration, and at less than 5 ppb O2 in the reactor water IGSCC was found to be completely inhibited in Ringhals 1. Finally it is shown that oxidizing impurities to the reactor water enchance IGSCC of sensitized austenitic stainless steel. (author)

324

Laboratory and lysimeter studies of glyphosate and aminomethylphosphonic acid in a sand and a clay soil.  

Science.gov (United States)

Due to the increasing concern about the appearance of glyphosate [N-(phosphonomethyl)glycine] and its major metabolite aminomethylphosphonic acid (AMPA) in natural waters, batch laboratory and lysimeter transport studies were performed to assess the potential for leaching of the compounds in two agricultural soils. Unlabeled and 14C-labeled glyphosate were added at a rate corresponding to 1.54 kg a.i. ha(-1) on undisturbed sand and clay columns. Leachate was sampled weekly during a period of 748 d for analyses of glyphosate, AMPA, total 14C, and particle-bound residues. Topsoil and subsoil samples were used for determination of glyphosate adsorption, glyphosate degradation, and formation of AMPA and its degradation. The influence of adsorption on glyphosate degradation was confirmed, giving very slow degradation rate in the clay soil (half-life 110-151 d). The kinetics of AMPA residues suggest that although AMPA is always more persistent than glyphosate when formed from glyphosate, its degradation rate can be faster than that of glyphosate. The kinetics also suggest that apart from glyphosate being transformed to AMPA, the sarcosine pathway can be just as significant. The long persistence of glyphosate was also confirmed in the lysimeter study, where glyphosate+AMPA residues constituted 59% of the initial amount of glyphosate added to the clay soil 748 d after application. Despite large amounts of precipitation in the autumn and winter after application, however, these residues were mainly located in the topsoil, and only 0.009 and 0.019% of the initial amount of glyphosate added leached during the whole study period in the sand and clay, respectively. No leaching ofAMPA occurred in the sand, whereas 0.03 g ha(-1) leached in the clay soil. PMID:21488498

Bergström, Lars; Börjesson, Elisabet; Stenström, John

2011-01-01

325

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)

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 cinco dias após a aplicação dos tratamentos. A aplicação de glyphosate não afetou a produção de CO2 pela microbiota do solo. A aplicação de endosulfan (isolado ou em mistura com o glyphosate reduziu a produção de CO2 pelos microrganismos do solo. A biomassa microbiana e o quociente metabólico foram menores nos tratamentos submetidos à aplicação de endosulfan isolado e em mistura com glyphosate, em comparação àqueles submetidos à aplicaçao de glyphosate isolado e à testemunha.

J.L. Pereira

2008-01-01

326

Time-integrated sampling of glyphosate in natural waters.  

Science.gov (United States)

Environmental monitoring of pesticide residues in surface water is often done with time-integrated sampling where a specified volume is sampled each hour during, e.g., a week, thus avoiding at momentary high or low extreme concentrations. However, sampling over an extended period of time can result in losses of easily degradable analytes, why the stability of the target analytes over the timespan of the sampling must be checked. Glyphosate is one of the most widely used herbicides. Because of its chemical complexity, glyphosate binds differently to metals and colloids at different pH, and the degradation may also be affected. Recovery of glyphosate from spiked natural waters after 1 and 3 weeks of storage was higher when the samples were acidified to approximately pH 2 rather than at their natural pH. Keeping the samples refrigerated to 4°C in darkness also enhanced recovery, while glyphosate losses were substantial from samples kept at their natural pH at 20 °C. Total loss of glyphosate was observed in some samples kept at natural pH, 20 °C, and daylight; a loss partly due to binding to metals or colloids that could only partially be reversed by acidification. For 1-week time-integrated sampling a small amount of hydrochloric acid in a piece of heat-sealed hydrophobic micro-porous tubing is added to the sampling bottles before deployment, a procedure that acidifies the samples during collection keeping them below pH 2 until analysis, thus minimising losses of glyphosate. The method also allows determination of the primary degradation product aminomethylphosphonic acid (AMPA). PMID:23044352

Kylin, H

2013-02-01

327

Palmitoleic acid reduces intramuscular lipid and restores insulin sensitivity in obese sheep  

Directory of Open Access Journals (Sweden)

Full Text Available Susan K Duckett, Gabriela Volpi-Lagreca, Mariano Alende, Nathan M LongAnimal and Veterinary Sciences Department, Clemson University, Clemson, SC, USAAbstract: Obese sheep were used to assess the effects of palmitoleic (C16:1 cis-9 acid infusion on lipogenesis and circulating insulin levels. Infusion of 10 mg/kg body weight (BW/day C16:1 intravenously in obese sheep reduced (P<0.01 weight gain by 77%. Serum palmitoleic levels increased (P<0.05 in a linear manner with increasing levels of C16:1 infusion. Cis-11 vaccenic (C18:1 cis-11 acid, a known elongation product of palmitoleic acid, was also elevated (P<0.05 in serum after 14 days and 21 days of infusion. Plasma insulin levels were lower (P<0.05 (10 mg/kg BW/day C16:1 than controls (0 mg/kg BW/day C16:1 at 14 days and 28 days of infusion. Infusion of C16:1 resulted in linear increases in tissue concentrations of palmitoleic, cis-11 vaccenic, eicosapentaenoic, and docosapentaenoic acids in a dose-dependent manner. Total lipid content of the semitendinosus (ST muscle and mesenteric adipose tissue was reduced (P<0.01 in both 5 mg/kg and 10 mg/kg BW C16:1 dose levels. Total lipid content and mean adipocyte size in the longissimus muscle was reduced (P<0.05 in the 10 mg/kg BW C16:1 dose level only, whereas total lipid content and adipocyte size of the subcutaneous adipose tissue was not altered. Total lipid content of the liver was also unchanged with C16:1 infusion. Palmitoleic acid infusion upregulated (P<0.05 acetyl-CoA carboxylase (ACC, fatty acid elongase-6 (ELOVL6, and Protein kinase, AMP-activated, alpha 1 catalytic subunit, transcript variant 1 (AMPK mRNA expressions in liver, subcutaneous adipose, and ST muscle compared to the controls. However, mRNA expression of glucose transporter type 4 (GLUT4 and carnitine palmitoyltransferase 1b (CPT1B differed between tissues. In the subcutaneous adipose and liver, C16:1 infusion upregulated (P<0.05 GLUT4 and CPT1B, whereas these genes were downregulated (P<0.05 in ST muscle with C16:1 infusion. These results show that C16:1 infusion for 28 days reduced weight gain, intramuscular adipocyte size and total lipid content, and circulating insulin levels. These changes appear to be mediated through alterations in expression of genes regulating glucose uptake and fatty acid oxidation specifically in the muscles.Keywords: adipocytes, longissimus muscle, lipogenesis, insulin level, serum, fatty acid

Duckett SK

2014-11-01

328

Tracing the origin and mobilization of Glyphosate and AMPA in a vineyard catchment  

Science.gov (United States)

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 following the first significant Glyphosate application in 2008. Assuming only target Glyphosate application, hardly any export of Ghyphosate and AMPA occurred. Therefore, non-target application at adjacent roads was introduced into the model. By assuming different mobilization processes of substances on the roads, our results show that storage of sorbed pesticides (e.g. road sides, unpaved roads) and storage without sorption (e.g. plant surface, paved roads) significantly contributed to the total pesticide residue export. Concluding, it is likely that the major part of pesticides in runoff of the Rouffach catchment originates from the roads rather than from the vine growing areas and that the mobilization process is a combination of both sorptive and non-sorptive substance storage. Thus, avoiding non-target pesticide application could largely help to mitigate water contamination in this catchment.

Gassmann, Matthias; Olsson, Oliver; Payraudeau, Sylvain; Imfeld, Gwenaël; Kümmerer, Klaus

2014-05-01

329

Photodegradation of glyphosate in the ferrioxalate system  

International Nuclear Information System (INIS)

The photoinduced degradation of glyphosate (GLP) in the ferrioxalate system was investigated under irradiation with a 250 W metal halide lamp (? ? 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(C2O4)2- and Fe(C2O4)33-, 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

330

Photodegradation of glyphosate in the ferrioxalate system  

Energy Technology Data Exchange (ETDEWEB)

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.

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

331

Reduced temperature sensitivity of soil respiration after a 17-year climate change experiment  

Science.gov (United States)

In 1994, a reciprocal soil transplant experiment was initiated between two elevations (310 m, warmer and drier, and 844 m, cooler and wetter) on Rattlesnake Mountain in southeastern Washington, USA, testing whether the microbial and biochemical dynamics that developed under cool, moist conditions would be destabilized under hot, dry conditions. In March 2012 we resampled the original transplanted soils to study longer-term changes in microbial community composition, soil C and N dynamics, and soil physical structure. These resampled cores were randomly assigned to climate-control chambers simulating the lower or upper site climates. We measured respiration throughout a 100-day incubation, coupled with biogeochemical analyses, to examine how these soils had responded to environmental changes over 17 years. Temperature and soil moisture were the primary drivers of CO2 evolution, but transplant source and destination both exerted significant effects. Most strikingly, respiration from cores originally from the hotter, low-elevation site that spent 17 years at the upper site exhibited almost no temperature sensitivity (Q10=1.07, 13-33 °C). Cores from the upper site had more carbon (~1.1% versus 0.8%), but equivalent C:N ratios, while soils incubated in the 'upper' chamber had greater N-acetylglucosaminidase and ?-glucosidase potentials. Tomographic reconstructions revealed that porosity, moisture content, grain size distribution, and organic C were highly heterogeneous, consistent with the observed macro-scale variability. These results suggest that the upper-site soils were more resilient to the 1994 transplant, but that there is a significantly altered microbial community in the transplanted soils, particularly the lower-to-upper cores, that has not recovered almost two decades after the original experiment. This raises more general questions of how current climate change will affect soil resistance to future perturbations, and how confidently we can model this response at larger scales.

Bond-Lamberty, B. P.; Bailey, V. L.; Fansler, S.; Liu, C.; Smith, J. L.; Bolton, H.

2012-12-01

332

High Sensitive Sensor Fabricated by Reduced Graphene Oxide/Polyvinyl Butyral Nanofibers for Detecting Cu (II) in Water.  

Science.gov (United States)

Graphene oxide (GO)/polyvinyl butyral (PVB) nanofibers were prepared by a simple electrospinning technique with PVB as matrix and GO as a functional nanomaterial. GO/PVB nanofibers on glassy carbon electrode (GCE) were reduced through electrochemical method to form reduced graphene oxide (RGO)/PVB nanofibers. The morphology and structure of GO/PVB nanofiber were studied by scanning election microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR). RGO/PVB modified GCE was used for fabricating an electrochemical sensor for detecting Cu (II) in water. The analysis results showed that RGO/PVB modified GCE had good analytical results with the linear range of 0.06-2.2??M, detection limit of 4.10?nM (S/N = 3), and the sensitivity of 103.51??A·?M(-1)·cm(-2). PMID:25694783

Ding, Rui; Luo, Zhimin; Ma, Xiuling; Fan, Xiaoping; Xue, Liqun; Lin, Xiuzhu; Chen, Sheng

2015-01-01

333

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  

Scientific Electronic Library Online (English)

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, isola [...] do 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. Abstract in english 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 herbicide [...] s 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 (g a.e. ha¹) alone (720/480, 720/720, 960/960, and 1.200/1.200) and the mixtures 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), and glyphosate + imazethapyr (720 + 40/480 + 40). The experimental design was completely randomized in a split-plot scheme with two checks, and four replicates. The variables analyzed were plant intoxication, plant height, stand,crop canopy, number of pods per plant, 100-grain mass, and yield. All the treatments promoted visual effects of plant intoxication on the soybean crop. However, yield loss was not observed in any of the situations studied.

D.G, Alonso; J, Constantin; R.S, Oliveira Jr; G, Santos; H.A, Dan; A.M, Oliveira Neto.

2013-03-01

334

Norepinephrine reduces ?-conotoxin-sensitive Ca2+ currents in renal afferent neurons in rats.  

Science.gov (United States)

Sympathetic efferent and peptidergic afferent renal nerves likely influence hypertensive and inflammatory kidney disease. Our recent investigation with confocal microscopy revealed that in the kidney sympathetic nerve endings are colocalized with afferent nerve fibers (Ditting T, Tiegs G, Rodionova K, Reeh PW, Neuhuber W, Freisinger W, Veelken R. Am J Physiol Renal Physiol 297: F1427-F1434, 2009; Veelken R, Vogel EM, Hilgers K, Amman K, Hartner A, Sass G, Neuhuber W, Tiegs G. J Am Soc Nephrol 19: 1371-1378, 2008). However, it is not known whether renal afferent nerves are influenced by sympathetic nerve activity. We tested the hypothesis that norepinephrine (NE) influences voltage-gated Ca(2+) channel currents in cultured renal dorsal root ganglion (DRG) neurons, i.e., the first-order neuron of the renal afferent pathway. DRG neurons (T11-L2) retrogradely labeled from the kidney and subsequently cultured, were investigated by whole-cell patch clamp. Voltage-gated calcium channels (VGCC) were investigated by voltage ramps (-100 to +80 mV, 300 ms, every 20 s). NE and appropriate adrenergic receptor antagonists were administered by microperfusion. NE (20 ?M) reduced VGCC-mediated currents by 10.4 ± 3.0% (P agatoxin IVA; nimodipine). Confocal microscopy revealed sympathetic innervation of DRGs and confirmed colocalization of afferent and efferent fibers within in the kidney. Hence NE released from intrarenal sympathetic nerve endings, or sympathetic fibers within the DRGs, or even circulating catecholamines, may influence the activity of peptidergic afferent nerve fibers through N-type Ca(2+) channels via an ?(2)-adrenoceptor-dependent mechanism. However, the exact site and the functional role of this interaction remains to be elucidated. PMID:22049399

Ditting, Tilmann; Linz, Peter; Freisinger, Wolfgang; Heinlein, Sonja; Reeh, Peter W; Fiedler, Christian; Siegel, Kirsten; Scrogin, Karie E; Neuhuber, Winfried; Veelken, Roland

2012-02-01

335

Translocação dos herbicidas glyphosate e imazamox em plantas de aguapé / Glyphosate and imazamox translocation in water hyacinth plants  

Scientific Electronic Library Online (English)

Full Text Available Entre as diversas plantas daninhas encontradas em ambientes aquáticos, a Eichhornia crassipes é uma das principais, sendo espécie indesejável para muitas atividades. O objetivo deste trabalho foi avaliar a translocação de glyphosate e imazamox em plantas de E. crassipes. Foram estudados oito interva [...] los de tempo para o corte das folhas que receberam os herbicidas: 2, 4, 6, 8, 12 e 24 horas após a aplicação (HAA) dos produtos, além de um tratamento sem corte das plantas (testemunha). Utilizaram-se glyphosate na dose de 2.160 g e.a. ha-1 (produto comercial - Rodeo) + 0,5% v v-1 do espalhante adesivo aterbane e imazamox na dose de 290,4 g i.a. ha-1 (produto comercial - Clearcast). Os tratamentos foram instalados em um delineamento experimental inteiramente casualizado com quatro repetições. O glyphosate apresentou um controle insatisfatório quando realizado os cortes das folhas em todos os períodos avaliados. O herbicida imazamox não proporcionou controle em até 12 HAA, enquanto que a partir de 24 HAA do herbicida o controle foi eficiente. Não houve uma grande mobilidade da molécula de glyphosate nas plantas de aguapé, sendo necessário um período superior a 24 horas para uma translocação satisfatória. Já para o imazamox um tempo de mínimo de 24 horas após a aplicação do herbicida foi suficiente para que ocorresse a translocação e um posterior controle. Abstract in english Eichhornia crassipes is one of the main weeds found in aquatic environments, being undesirable for many activities. The aim of this study was to evaluate the translocation of glyphosate and imazamox in E. crassipes. Eight intervals were studied for cutting leaves that received herbicides: 2, 4, 6, 8 [...] , 12 and 24 hours after application (HAA), and a treatment with no cutting (untreated). The glyphosate dose was 2,160 g a.e. ha-1 (commercial product - Rodeo) + 0.5% v v-1 Aterbane adhesive spreader and imazamox at 290.4 g i.a. ha-1 (commercial product - Clearcast). The treatments were installed in a completely randomized design with four replications. Glyphosate showed a bad control for all the periods of leaf cutting. The imazamox did not provide control within 12 HAA, while from 24 HAA onward the control was effective. There was not a great mobility of the glyphosate molecule in water hyacinth plants, a period above 24 hours being needed for a satisfactory translocation. For imazamox at least 24 hours were needed after herbicide application for the translocation to occur along with subsequent control.

C.F. de, Campos; H.S., Vitorino; G.S.F. de, Souza; D.C. de, Santana; D., Martins.

2013-06-01

336

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

Scientific Electronic Library Online (English)

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. Abstract in english 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 experiments were developed under greenhouse conditions, with Bengal dayflower and alexandergrass plants being submitted to a 9 x6 factorial scheme, where nine treatments were the glyphosate rates and six, the weed phenological stages, varying between unfolding of the first true leaf and the beginning of flowering. Using dose-response curves and polynomial regressions, it could be concluded that the Bengal dayflower phenological stages significantly contribute to the species'degree of glyphosate-tolerance, since, compared to alexandergrass, Bengal dayflower plants became four times more tolerant to glyphosate at every ten units of phenological development at the BBCH scale. These considerations have an important practical applicability, justifying chemical control measurements at the initial growth stages of Bengal dayflower.

A.C.R, Dias; S.J.P, Carvalho; P.J, Christoffoleti.

2013-03-01

337

Reduced Metabolic Insulin Sensitivity Following Sub-acute Exposures to Low Levels of Ambient Fine Particulate Matter Air Pollution  

Science.gov (United States)

Epidemiological studies suggest that fine particulate matter (PM2.5) may increase the risk for developing diabetes mellitus (DM). To evaluate possible mechanisms explaining these associations, we investigated if sub-acute ambient-level exposures can impair insulin sensitivity. Twenty-five healthy adults living in rural Michigan were transported to an urban location for 5 consecutive days (exposure-block) of daily 4- to 5-hour-long ambient air pollution exposures. Health outcomes, including the homeostasis model assessment of insulin resistance (HOMA-IR) the primary outcome of insulin sensitivity, were measured at 3 time points in relation to exposure-blocks: 7 days prior to start; on the last exposure-day; and 7 days after completion. PM2.5 was monitored at the urban exposure site and at community monitors near subjects’ residences. We calculated 3 “sub-acute” exposure periods (approximately 5-days-long) starting retrospective from the time of health outcome measurements (PM2.5 ranges: 9.7±3.9 to 11.2±3.9 µg•m?3). A 10 µg•m?3 increase in sub-acute PM2.5 exposures was associated with increased HOMA-IR (+0.7, 95% confidence interval (CI) 0.1 to 1.3; p=0.023) and reduced heart rate variability (standard deviation of normal-to-normal intervals [?13.1 msec, 95%CI ?25.3 to ?0.9; p=0.035]). No alterations in other outcomes (inflammatory markers, vascular function) occurred in relation to PM2.5 exposures. Our findings suggest that ambient PM2.5, even at low levels, may reduce metabolic insulin sensitivity supporting the plausibility that air pollution could potentiate the development of DM. PMID:22901427

Brook, Robert D; Xu, Xiaohua; Bard, Robert L; Dvonch, J Timothy; Morishita, Masako; Kaciroti, Niko; Sun, Qinghua; Harkema, Jack; Rajagopalan, Sanjay

2015-01-01

338

Glyphosate inhibition of ferric reductase activity in iron deficient sunflower roots.  

Science.gov (United States)

Iron (Fe) deficiency is increasingly being observed in cropping systems with frequent glyphosate applications. A likely reason for this is that glyphosate interferes with root uptake of Fe by inhibiting ferric reductase in roots required for Fe acquisition by dicot and nongrass species. This study investigated the role of drift rates of glyphosate (0.32, 0.95 or 1.89 mm glyphosate corresponding to 1, 3 and 6% of the recommended herbicidal dose, respectively) on ferric reductase activity of sunflower (Helianthus annuus) roots grown under Fe deficiency conditions. Application of 1.89 mm glyphosate resulted in almost 50% inhibition of ferric reductase within 6 h and complete inhibition 24 h after the treatment. Even at lower rates of glyphosate (e.g. 0.32 mm and 0.95 mm), ferric reductase was inhibited. Soluble sugar concentration and the NAD(P)H oxidizing capacity of apical roots were not decreased by the glyphosate applications. To our knowledge, this is the first study reporting the effects of glyphosate on ferric reductase activity. The nature of the inhibitory effect of glyphosate on ferric reductase could not be identified. Impaired ferric reductase could be a major reason for the increasingly observed Fe deficiency in cropping systems associated with widespread glyphosate usage. PMID:18179601

Ozturk, Levent; Yazici, Atilla; Eker, Selim; Gokmen, Ozgur; Römheld, Volker; Cakmak, Ismail

2008-01-01

339

Glyphosate-rich air samples induce IL-33, TSLP and generate IL-13 dependent airway inflammation.  

Science.gov (United States)

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. PMID:25172162

Kumar, Sudhir; Khodoun, Marat; Kettleson, Eric M; McKnight, Christopher; Reponen, Tiina; Grinshpun, Sergey A; Adhikari, Atin

2014-11-01

340

Influência de pontas de pulverização e adjuvantes na deriva em caldas com glyphosate Influence on spray drift of nozzles and adjuvants with a glyphosate spray solution  

Directory of Open Access Journals (Sweden)

Full Text Available O uso inadequado da tecnologia de aplicação de agrotóxicos, relacionados ao uso de pontas de pulverização e adição de adjuvantes, resulta diretamente em um maior risco de deriva. Objetivou-se como trabalho quantificar a deriva gerada por pontas de pulverização com e sem indução de ar, em aplicações de glyphosate e adjuvantes. O experimento foi realizado em túnel de vento, com o herbicida glyphosate isolado ou em mistura com ureia ou adjuvante redutor de deriva (LI700. As coletas foram realizadas, com fios de polietileno, nas distâncias de 5,0; 10,0 e 15,0 m em relação à barra e nas alturas de 0,2; 0,4; 0,6; 0,8 e 1,0 m em relação ao piso do túnel, a deriva foi aferida por meio do processo de condutividade elétrica. Os resultados apresentaram maior deriva nas menores alturas, tendo igual comportamento para todas as caldas e em todas as distâncias. A ponta de jato plano com indução de ar (AVI 110-015 proporcionou menor deriva em relação à ponta jato plano padrão (AXI 110-015, para todas as caldas avaliadas. Para a ponta de jato plano padrão o acréscimo de adjuvante reduziu a deriva para as três distâncias avaliadas em relação à calda contendo somente o herbicida. Já para a ponta de jato plano com indução de ar a ureia elevou a deriva para todas as distâncias em relação às outras caldas. A ureia pode ser utilizada em aplicações com o modelo de ponta jato plano padrão, por diminuir os riscos de deriva.The improper use of pesticide-application technology, related to the use of spray nozzles and the addition of adjuvants, is directly related to a greater risk of drift. This study aimed to quantify the spray drift generated by nozzles, both with and without air induction, in applications of glyphosate and adjuvants. The experiment was conducted in a wind tunnel, using the herbicide, glyphosate, either pure or in combination with urea or a drift-reducing adjuvant (LI700. Collections were made on polyethylene strings, at distances of 5.0, 10.0 and 15.0 m from the spray-boom, and at heights of 0.2, 0.4, 0.6, 0.8 and 1.0 m from the floor of the tunnel; the drift was measured using a process of electrical conductivity. The results showed greater drift at the lower heights, giving the same results for all solutions and at all distances. The flat nozzle with air induction (AVI 110-015 gave a smaller drift relative to the standard flat nozzle (AXI 110-015 for all solutions tested. With the standard flat nozzle, adding an adjuvant reduced the drift at the three distances tested, for the solution containing pure herbicide. For the flat fan nozzle with air induction however, the urea increased drift at all distances compared to other the spray solutions. Urea can be employed in applications where the standard flat tip model is used, as it reduces the risk of drift.

Marco Antonio Gandolfo

2013-09-01