Field and greenhouse studies were conducted to investigate the role of water stress and time of glyphosate spraying in the variation in glyphosate efficacy. Data on water potential, foliar sugar and starch content, weather, and growth response were gathered for loblolly pine and four of its major competitors on 16 operationally sprayed tracts in Virginia. Glyphosate successfully released loblolly pine on all tracts. Control of white oaks was significantly related to foliar sugar concentration. Water potential and weather variables were not related to glyphosate efficacy for any species. Seedlings of loblolly pine, red maple, and sweetgum were raised in a greenhouse and nursery environment. At the end of the second growing season, three water stress treatments were imposed on each species at each of four glyphosate application dates. ¹⁴C-glyphosate was applied to a subsample of seedlings. Timing of application. water stress, or both significantly affected susceptibility of all three species to glyphosate. Efficacy for all three species corresponded to that expected from field data. Differences in species susceptibility to glyphosate were explained by differences in ¹⁴C-glyphosate translocation, but there was no difference among species in absorption of glyphosate. Efficacy changes across application dates followed seasonal changes in foliar sugar concentration. / Master of Science

Des niveaux appréciables de glyphosate, l'herbicide le plus utilisé mondialement, et de ses principaux métabolites, les acides aminométhylphosphonique (AMPA) et méthylphosphonique (MPA) sont retrouvés chez l'humain. Plusieurs études ont associé la présence du glyphosate à des problèmes de santé. Des effets sur les cellules immunitaires et leurs fonctions ont été rapportés. Cependant, les effets de cette molécule et de ses métabolites sur les neutrophiles, les leucocytes les plus abondants dans le sang humain, sont encore peu documentés. Étant donné la présence de ces molécules dans le sang, nous avions pour objectif de déterminer les effets de l'exposition au glyphosate et aux métabolites AMPA et MPA sur la viabilité, le métabolisme énergétique et les principales fonctions antimicrobiennes des neutrophiles. Nous avons exposé des neutrophiles isolés du sang de donneurs sains hommes et femmes à différentes concentrations de glyphosate et de ses métabolites, avant de déterminer les effets de l'exposition sur les cellules. Nous avons observé que l'exposition aux molécules n'affecte pas la glycolyse et la respiration mitochondriale des neutrophiles. Cependant, des altérations au niveau de différentes voies métaboliques pourraient affecter les fonctions des neutrophiles. En effet, bien que les neutrophiles étaient initialement considérés comme presque exclusivement glycolytiques, de nombreuses études ont montré qu'ils utilisent plusieurs voies métaboliques alternatives pour leur maturation et effectuer leurs fonctions. Nous avons observé que le glyphosate augmente la production d'espèces réactives de l'oxygène chez les neutrophiles isolés de donneurs des deux sexes. Le glyphosate et ses métabolites modulent aussi la production et la sécrétion de CXCL8/IL-8 en fonction du sexe des donneurs. Ces résultats suggèrent que le glyphosate et ses métabolites affectent les fonctions antimicrobiennes des neutrophiles humains dépendamment du sexe, ce qui pourrait être associé à des problèmes de santé. Les progrès des connaissances permettront d'améliorer les réglementations afin de protéger le public. / Significant levels of glyphosate, the world's most widely used herbicide, and its primary metabolites, aminomethylphosphonic acid (AMPA) and methylphosphonic acid (MPA), are detected in humans. Several studies have linked the presence of glyphosate in humans to health problems. Effects on immune cells and their functions have also been reported. However, the effects of this molecule and its metabolites on neutrophils, the most abundant leukocytes in the human bloodstream, are still poorly documented. Given the presence of these molecules in the blood, our aim was to determine the effects of exposure to glyphosate and its metabolites AMPA and MPA on the viability, energy metabolism, and essential antimicrobial functions of neutrophils. We, therefore, exposed neutrophils isolated from the blood of healthy male and female donors to different concentrations of glyphosate and its metabolites, before determining the effects of exposure on the cells. We observed that exposure to the molecules did not affect neutrophil glycolysis and mitochondrial respiration. However, alterations in various metabolic pathways could affect neutrophil function. Indeed, although neutrophils were initially considered to be almost exclusively glycolytic, numerous studies have shown that they use several alternative metabolic pathways for their maturation and to perform their functions. We have observed that glyphosate increases the production of reactive oxygen species in neutrophils isolated from donors of both sexes. Glyphosate and its metabolites also modulated CXCL8/IL-8 production and secretion according to donor sex. These results suggest that glyphosate and its metabolites affect the antimicrobial functions of human neutrophils in a sex-dependent manner, which could be associated with health problems. Advances in knowledge will help improve regulations to protect the public.

L’utilisation des pesticides n’a cessé d’augmenter en particulier le glyphosate, herbicide utilisé principalement dans l’agriculture. Ses effets ont été démontrés néfastes sur l’environnement et sur la santé humaine. Bien que la plupart du glyphosate résiduel soit adsorbé par les constituants du sol, une partie peut être désorbée ou atteindre les eaux de surface par érosion. Le renforcement des normes de qualité de l'eau en milieu agricole et urbain entraîne le développement de nouveaux procédés. Les photocatalyseurs à base de TiO2 peuvent procurer une solution attrayante pour l’élimination de cet herbicide. Actif uniquement dans le domaine de l’UV qui représente 4% du rayonnement solaire, étendre cette réactivité photocatalytique dans le domaine du visible est un enjeu majeur. Le dopage du TiO2 à l’azote et au graphène a permis une élimination totale du glyphosate au bout de 30 minutes. Après sa synthèse, le photocatalyseur GR-N/TiO2 a été caractérisé par différentes techniques à savoir la diffraction des rayons X (DRX), l’infrarouge à transformée de Fourier (FTIR), la spectroscopie de photoélectrons X (XPS) et la microscopie électronique par transmission (TEM). L'activité photocatalytique est testée sur la dégradation du glyphosate sous irradiation de la lumière visible. Les résultats montrent que le composite GR-N/TiO2 peut effectivement photodégrader le glyphosate grâce à une amélioration impressionnante de l’activité photocatalytique due à une grande adsorption du glyphosate sur le nanomatériau synthétisé et à l’extension de l'absorption au domaine du visible. / Pesticide use has been increasing especially for glyphosate an herbicide used mainly in agriculture. Its effects have been proven harmful to the environment and human health. Although most of the residual glyphosate can be adsorbed by the soil constituents, a part may be desorbed or reach surface waters by erosion. Strengthening the quality standards of water in agricultural and urban areas leads to the development of new processes. TiO2- based photocatalysts can provide an attractive solution for the elimination of this herbicide. Active under UV light which represents only 4% of solar radiation, extending this photocatalytic activity to the visible range is a major issue. Doping TiO2 with nitrogen and graphene shows a total elimination of glyphosate within 30 minutes of reaction. The photocatalyst GR-N/TiO2 was characterized by various techniques namely X-ray diffraction (XRD), infrared Fourier transform (FTIR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The photocatalytic activity was tested under visible light irradiation to glyphosate degradation. Results showed that the GRN/ TiO2 composite can effectively photodegrade glyphosate with an impressive improvement of the photocatalytic activity due to a large adsorption of glyphosate on the synthesized nanomaterial and the extension of the absorption to the visible light region conferred to photocatalyst.

Dissertation submitted in partial compliance with the requirements for the Masters Degree in Technology, 2010. / Water storage dams play an important part in the collection and purification of water destined for human consumption. However, the nutrient rich silt in these dams promotes rapid growth of aquatic plants which tend to block out light and air. Glyphosate is universally used as the effective non-selective herbicide for the control of aquatic plants in rivers and dams. Invariably there is residual glyphosate present in water after spraying of dams and rivers with glyphosate herbicide. The amount of residual glyphosate is difficult to determine on account of high solubility of glyphosate in water. Thus a method of sample preparation and a sensitive HPLC method for the detection of trace amounts of glyphosate and its major metabolite aminomethylphosphonic acid (AMPA) in water is required. A crucial step in sample preparation is pre-column derivitization of glyphosate with 9-fluorenylmethyl chloroformate (FMOC-Cl). For sample pretreatment, water samples were derivatized with FMOC-Cl at pH 9, extracted with ethyl acetate and sample clean-up was carried out by passing a sample through the SPE cartridge. For SPE, recovery studies were done to choose a suitable cartridge for glyphosate and AMPA analysis. The following cartridges were compared, namely, C18, Oasis HLB and Oasis MAX SPE cartridges. Best recoveries (101% for glyphosate and 90% for AMPA) were obtained using 500 mg of C18 solid-phase extraction cartridge. The eluent from SPE cartridge was injected into HPLC column. Three types of separation columns (namely; C18 column, silica based amino column and polymeric amino column) were compared for the separation of glyphosate and AMPA. The best separation of glyphosate and AMPA in water samples was achieved using a polymeric amino column and a mobile phase at pH 10 which contained a mixture of acetonitrile and 0.05 M phosphate buffer (pH 10) 55:45, (v/v) respectively. The method was validated by spiking tap water , deionized water and river water at a level of 100 μg/l. Recoveries were in the range of 77% -111% for both analytes. The method was also used in determining the levels of glyphosate and AMPA in environmental samples. This method gave detection limits of 3.2 μg/l and 0.23 μg/l for glyphosate and AMPA respectively. The limits of quantification obtained for this method were 10.5 μg/l and 3.2 μg/l for glyphosate and AMPA respectively. / Eskom Tertiary Education Support Programme (TESP) Durban University of Technology.

Mundialmente, a soja é considerada uma das principais fontes de produção de óleos e proteínas vegetais para alimentação humana e animal. Constitui-se atualmente um dos produtos de maior importância na economia brasileira. É notório o crescimento das áreas ocupadas pelas lavouras de soja no Brasil, que na safra 2014/2015 atingiram 32,09 milhões de hectares, com previsão de expansão para 32,20 milhões de hectares para a safra 2015/2016. Outro aspecto a ser salientado é que as lavouras de soja RR (Roundup Ready) corresponderam a 93,5%, da área total cultivada com soja no Brasil na safra 2014/2015. Cultivares STS (Soja Tolerante à Sulfoniluréias) contém um gene que aumenta a degradação de alguns herbicidas na planta, como por exemplo, o chlorimuron-ethyl, para o qual são posicionados tolerando doses até quatro vezes as doses recomendadas para cultivares não tolerantes, sem apresentar danos significativos. A soja STS foi desenvolvida através da técnica de mutagênese de sementes utilizando o agente alquilante etilmetanosulfonato (EMS), não sendo uma cultura transgênica. Os objetivos do presente trabalho foram: avaliar a seletividade do herbicida chlorimuron-ethyl aplicado em pós-emergência de soja RR/STS; avaliar a seletividade de herbicidas inibidores da ALS aplicados em pós-emergência de soja RR/STS. Para tanto foram conduzidos dois experimentos principais. O primeiro conduzido durante quatro safras (2011/2012 a 2014/2015), os tratamentos foram constituídos por sete doses do herbicida chlorimuron-ethyl (0, 15, 30, 45, 60, 75 e 90 g i. a. ha-1). Foi realizada avaliação das variáveis relacionadas ao desempenho agronômico (altura, número de vagens por planta, produtividade, e massa de mil sementes). O segundo durante a safra 2014/2015 no campo e casa de vegetação, em que a soja RR/STS foi submetida à aplicação de herbicidas inibidores da ALS, associados ou não ao glyphosate. Foi realizada avaliação de fitointoxicação, índice SPAD, bem como variáveis relacionadas ao desempenho agronômico para o experimento no campo (número de vagens por planta e produtividade). Os cultivares de soja CD 250 e CD 2630 RR/STS apresentaram-se tolerantes para aplicação, em pós-emergência (V4), do herbicida chlorimuron-ethyl até a dose de 90 g i. a. ha-1. O cultivar de soja CD 2630 RR/STS apresentou-se tolerante à aplicação, em pós-emergência, dos herbicidas utilizados, isolada ou em associação com glyphosate. Exceção feita ao metsulfuron-methy (2,4 g i. a. ha-1), associado ou não com glyphosate (960 g e. a. ha-1). / Worldwide soybean is considered one of the major sources of production of vegetable oils and proteins for food and feed. It currently is one of the most important products in the Brazilian economy. It is notable growth areas occupied by soybean crops in Brazil, that in the 2014/2015 season reached 32.09 million hectares, with expansion forecast to 32.20 million hectares for the season 2015/2016. Another aspect to be noted is that the RR soybean (Roundup Ready) crops corresponded to 93.5% of the total area cultivated with soybeans in Brazil in the 2014/2015 season. Cultivars STS (Sulfonylurea Tolerant Soybeans) contains a gene that increases the degradation of some herbicides in the plant, for example, chlorimuron-ethyl, to which are positioned tolerated doses up to four times the recommended dosages for nontolerant cultivars, without presenting significant damage. STS soybean was developed by seed mutagenesis technique using the alkylating agent ethyl methane sulfonate (EMS), not being a transgenic crop. The aims of this study were to evaluate the selectivity of the herbicide chlorimuron-ethyl applied post-emergence of RR/STS soybean; evaluate the selectivity of ALS-inhibiting herbicides applied postemergence of RR/STS soybean. Therefore, two main experiments were conducted. The first conducted for four seasons (2011/2012 to 2014/2015), the treatments were seven doses of the herbicide chlorimuron-ethyl (0, 15, 30, 45, 60, 75 and 90 g a. i. ha-1). Performed an assessment of variables related to agronomic performance (height, number of pods per plant, yield and mass of one thousand seeds). The second during the 2014/2014 season in the field and the greenhouse, where RR/STS soybean was subjected to application of ALS inhibitor herbicides, with or without glyphosate. It was conducted evaluation phytointoxication, SPAD index, as well as variables related to agronomic performance (number of pods per plant and productivity). The soybean cultivars CD 250 and CD 2630 RR/STS were tolerant to application, post-emergence (V4) of herbicide chlorimuron-ethyl up to a dose of 90 g a. i. ha-1. Cultivar CD 2630 RR/STS presented tolerance to application in postemergence herbicides used alone or in combination with glyphosate. Except for the metsulfuron-methy (2.4 g a. i. ha-1), associated or not with glyphosate (960 g a. e. ha-1).

Mundialmente, a soja é considerada uma das principais fontes de produção de óleos e proteínas vegetais para alimentação humana e animal. Constitui-se atualmente um dos produtos de maior importância na economia brasileira. É notório o crescimento das áreas ocupadas pelas lavouras de soja no Brasil, que na safra 2014/2015 atingiram 32,09 milhões de hectares, com previsão de expansão para 32,20 milhões de hectares para a safra 2015/2016. Outro aspecto a ser salientado é que as lavouras de soja RR (Roundup Ready) corresponderam a 93,5%, da área total cultivada com soja no Brasil na safra 2014/2015. Cultivares STS (Soja Tolerante à Sulfoniluréias) contém um gene que aumenta a degradação de alguns herbicidas na planta, como por exemplo, o chlorimuron-ethyl, para o qual são posicionados tolerando doses até quatro vezes as doses recomendadas para cultivares não tolerantes, sem apresentar danos significativos. A soja STS foi desenvolvida através da técnica de mutagênese de sementes utilizando o agente alquilante etilmetanosulfonato (EMS), não sendo uma cultura transgênica. Os objetivos do presente trabalho foram: avaliar a seletividade do herbicida chlorimuron-ethyl aplicado em pós-emergência de soja RR/STS; avaliar a seletividade de herbicidas inibidores da ALS aplicados em pós-emergência de soja RR/STS. Para tanto foram conduzidos dois experimentos principais. O primeiro conduzido durante quatro safras (2011/2012 a 2014/2015), os tratamentos foram constituídos por sete doses do herbicida chlorimuron-ethyl (0, 15, 30, 45, 60, 75 e 90 g i. a. ha-1). Foi realizada avaliação das variáveis relacionadas ao desempenho agronômico (altura, número de vagens por planta, produtividade, e massa de mil sementes). O segundo durante a safra 2014/2015 no campo e casa de vegetação, em que a soja RR/STS foi submetida à aplicação de herbicidas inibidores da ALS, associados ou não ao glyphosate. Foi realizada avaliação de fitointoxicação, índice SPAD, bem como variáveis relacionadas ao desempenho agronômico para o experimento no campo (número de vagens por planta e produtividade). Os cultivares de soja CD 250 e CD 2630 RR/STS apresentaram-se tolerantes para aplicação, em pós-emergência (V4), do herbicida chlorimuron-ethyl até a dose de 90 g i. a. ha-1. O cultivar de soja CD 2630 RR/STS apresentou-se tolerante à aplicação, em pós-emergência, dos herbicidas utilizados, isolada ou em associação com glyphosate. Exceção feita ao metsulfuron-methy (2,4 g i. a. ha-1), associado ou não com glyphosate (960 g e. a. ha-1). / Worldwide soybean is considered one of the major sources of production of vegetable oils and proteins for food and feed. It currently is one of the most important products in the Brazilian economy. It is notable growth areas occupied by soybean crops in Brazil, that in the 2014/2015 season reached 32.09 million hectares, with expansion forecast to 32.20 million hectares for the season 2015/2016. Another aspect to be noted is that the RR soybean (Roundup Ready) crops corresponded to 93.5% of the total area cultivated with soybeans in Brazil in the 2014/2015 season. Cultivars STS (Sulfonylurea Tolerant Soybeans) contains a gene that increases the degradation of some herbicides in the plant, for example, chlorimuron-ethyl, to which are positioned tolerated doses up to four times the recommended dosages for nontolerant cultivars, without presenting significant damage. STS soybean was developed by seed mutagenesis technique using the alkylating agent ethyl methane sulfonate (EMS), not being a transgenic crop. The aims of this study were to evaluate the selectivity of the herbicide chlorimuron-ethyl applied post-emergence of RR/STS soybean; evaluate the selectivity of ALS-inhibiting herbicides applied postemergence of RR/STS soybean. Therefore, two main experiments were conducted. The first conducted for four seasons (2011/2012 to 2014/2015), the treatments were seven doses of the herbicide chlorimuron-ethyl (0, 15, 30, 45, 60, 75 and 90 g a. i. ha-1). Performed an assessment of variables related to agronomic performance (height, number of pods per plant, yield and mass of one thousand seeds). The second during the 2014/2014 season in the field and the greenhouse, where RR/STS soybean was subjected to application of ALS inhibitor herbicides, with or without glyphosate. It was conducted evaluation phytointoxication, SPAD index, as well as variables related to agronomic performance (number of pods per plant and productivity). The soybean cultivars CD 250 and CD 2630 RR/STS were tolerant to application, post-emergence (V4) of herbicide chlorimuron-ethyl up to a dose of 90 g a. i. ha-1. Cultivar CD 2630 RR/STS presented tolerance to application in postemergence herbicides used alone or in combination with glyphosate. Except for the metsulfuron-methy (2.4 g a. i. ha-1), associated or not with glyphosate (960 g a. e. ha-1).

Canada fleabane is the second glyphosate-resistant (GR) weed species to be confirmed in Ontario. In 2010, GR populations were identified at eight sites in Essex County. In 2011 and 2012, 147 additional sites across eight counties were confirmed to be resistant. Twelve and seven sites were identified with multiple resistance (glyphosate and cloransulam) in 2011 and 2012, respectively, across five counties. In soybeans, preplant tankmixes of glyphosate (900 g a.e.ha-1) plus saflufenacil (25 g a.i. ha-1), saflufenacil/dimethenamid-p (245 g a.i. ha-1), metribuzin (1120 g a.i. ha-1), or flumetsulam (70 g a.i. ha-1) provided greater than 87% up to 8 weeks after application (WAA). Glyphosate rates 21 to 48X the label rate (900 g a.e. ha-1) were required for 95% control. Postemergence tankmixes did not provide acceptable control. In dicamba-tolerant soybean, dicamba applied preplant at 600 g a.e. ha-1 provided the most consistent control of GR Canada fleabane. / Monsanto Canada Inc., Grain Farmers of Ontario, Agricultural Adaptation Council

Made available in DSpace on 2016-12-08T16:44:47Z (GMT). No. of bitstreams: 1 PGPV14MA144.pdf: 861442 bytes, checksum: c0bd112f70401acc3674e49bcc979cf3 (MD5) Previous issue date: 2014-07-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of the present work is to analyze the response of plants of ryegrass (Lolium multiflorum) and wavy-leaved fleabane (Conyza bonariensis) to increasing doses of glyphosate to detect herbicide susceptible and resistant biotypes and to evaluate the physiological quality of seeds of these biotypes to verify the relationship between the resistance and the physiological seed quality of these weeds. Ryegrass and wavy-leaved fleabane plants were exposed to increasing doses of glyphosate, ranging from 0 up to 1440 g ae ha-1, and the fresh weight were weighted 21 days after application, for dose-response tests. Seeds were subjected to tests of physiological quality (germination, cold test and accelerated aging). The experimental design was completely randomized, using ten replicates for ryegrass and six replicates for wavy-leaved fleabane in the dose-response tests, and four replicates for tests of physiological seed quality. All studied biotypes of ryegrass and wavy-leaved fleabane showed differential response due to increasing doses of glyphosate. Ryegrass resistant biotypes showed resistance factors (RF) of 3.0 (Passo Fundo) and 8.3 (Vacaria), while the susceptible ones showed FR of 1.5 (Ponte Serrada) and 1.0 (Lages). Wavy-leaved horseweed resistant biotypes showed FR 2.0 (Papanduva) and 15.5 (Campos Novos), and the susceptible biotype FR 1.0 (Lages). In the tests of physiological seed quality, ryegrass biotype of Lages showed the best performance for germination (64%) and accelerated aging (86%) tests compared to the other biotypes. For the cold test, the biotype of Vacaria showed the best result with 86% of germination, while the biotype of Passo Fundo showed the worst results in all tests. Biotypes of wavy-leaved fleabane did not differ in germination. For Lages and Papanduva wavy-leaved fleabane, itwas found the biotypes responded positively to cold stress (66 and 61%, respectively). The biotype of Campos Novos, with high resistance to the herbicide, did not withstand the stress exposure, presenting similar to germination (34%) compared to the cold test (28%) result. The seeds of the wavy-leaved fleabane biotypes responded negatively to accelerated aging, in that the biotype of Lages showed the best result (12%), while biotypes of Papanduva and Campos Novos showed 4.0 and 2.0%, respectively. Biotypes of ryegrass with differential response to glyphosate present distinct percentage of germination and vigor of seeds, although it is not directly dependent on herbicide resistance. Susceptible biotypes of wavy-leaved fleabane and the biotype with low degree of resistance to glyphosate are more vigorous than the resistant biotype. The physiological seed quality of ryegrass and wavy-leaved fleabane is not directly related to the resistance to glyphosate, and the influence of environment is probably more significant than the resistance / Objetivou-se com o presente trabalho analisar a resposta de plantas de azevém (Lolium multiflorum) e buva (Conyza bonariensis) a doses crescentes do glyphosate para detecção de biótipos suscetíveis e resistentes ao herbicida e avaliar a qualidade fisiológica de sementes desses biótipos para verificar a relação entre a resistência e a qualidade fisiológica de sementes dessas plantas daninhas. Plantas de azevém e buva foram expostas a doses crescentes de glyphosate, variando de 0 a 1.440 g e.a. ha-1, com avaliação da massa fresca após 21 dias da aplicação. As sementes foram submetidas a testes de qualidade fisiológica (germinação, teste de frio e envelhecimento acelerado). O delineamento experimental utilizado foi o inteiramente casualizado, com dez repetições para o azevém e seis repetições para a buva no teste de dose-resposta e com quatro repetições para os testes de qualidade fisiológica de sementes. Todos os biótipos estudados de azevém e buva apresentaram resposta diferencial ao aumento de dose do herbicida glyphosate. Os biótipos de azevém resistentes apresentaram fatores de resistência (FR) igual a 3,0 (Passo Fundo) e 8,3 (Vacaria) enquanto os susceptíveis 1,5 (Ponte Serrada) e 1,0 (Lages). Os biótipos de buva resistentes apresentaram FR de 2,0 (Papanduva) e 15,5 (Campos Novos) e o biótipo susceptível FR de 1,0 (Lages). Nos testes de qualidade fisiológica o biótipo de azevém de Lages apresentou melhor desempenho para os testes de germinação (64%) e envelhecimento acelerado (86%) em relação aos demais biótipos. Para o teste de frio, o biótipo de Vacaria apresentou o melhor resultado com 86%. Enquanto que o biótipo de Passo Fundo apresentou os piores resultados em todos os testes realizados. Os biótipos de buva não se diferenciaram no teste de germinação. Para os biótipos Lages e Papanduva foi verificado que o vigor desses biótipos responderam positivamente ao estresse pelo frio (66 e 61% respectivamente). O biótipo de Campos Novos, com elevada resistência ao herbicida, não suportou a exposição ao estresse, apresentando resultado semelhante ao teste de germinação (34%) em relação ao teste de frio (28%). As sementes dos biótipos de buva responderam negativamente ao teste de envelhecimento acelerado, em que o biótipo de Lages apresentou o melhor resultado com 12%, enquanto os biótipos de Papanduva e Campos Novos apresentaram 4,0 e 2,0% respectivamente. Os biótipos de azevém com resposta diferencial ao glyphosate apresentam porcentagem de germinação e vigor de sementes distintos, porém não diretamente dependentes da resistência ao herbicida. Os biótipos de buva suscetível e com baixo grau de resistência ao herbicida glyphosate são mais vigorosos que o biótipo resistente. A qualidade fisiológica de sementes de azevém e buva não está diretamente relacionada com a resistência ao herbicida glyphosate, sendo a influência do ambiente, provavelmente, mais significativa do que a resistência

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-02-06T14:01:10Z No. of bitstreams: 2 Dissertação - Laís de Brito Rodrigues - 2016.pdf: 1513682 bytes, checksum: f083fb3e5a8cc62aa1d67ed3d78fbfe1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-02-06T14:01:33Z (GMT) No. of bitstreams: 2 Dissertação - Laís de Brito Rodrigues - 2016.pdf: 1513682 bytes, checksum: f083fb3e5a8cc62aa1d67ed3d78fbfe1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-02-06T14:01:33Z (GMT). No. of bitstreams: 2 Dissertação - Laís de Brito Rodrigues - 2016.pdf: 1513682 bytes, checksum: f083fb3e5a8cc62aa1d67ed3d78fbfe1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Glyphosate-based herbicides are the most commonly used worldwide due to their effectiveness and they are relatively non-toxic to non-target species. Unlimited and uncontrolled use of such pesticides can lead to serious consequences in terms of human health and ecological balance. We evaluated the acute toxicity of active ingredient glyphosate (GLI) and two glyphosate-based formulations, Roundup Original (RUP) and Glyphosate AKB 480 (AKB) on different organisms: seeds of cucumber (Cucumis sativus), lettuce (Lactuca sativa) and tomato (Lycopersicon esculentum), microcrustacean Artemia salina and zebrafish (Danio rerio) early life stages. For germination endpoint, L. esculentum presented sensitivity (EC50 = 702.10 mg/L) for AKB and L. sativa for GLI exposure (EC50 = 612.30 mg/l) whereas the three substances induced significant toxic effect on root elongation of all tested species. GLI, RUP and AKB induced significant toxicity to A. salina and were classified as Category III according to Globally Harmonized Classification System (GHS) criteria. However, RUP (LC50-48h of 39.4 mg/L) was more toxic than GLI (LC50-48h of 65.24 mg/L) and AKB (LC50-48h of 104.20 mg/L). For embryo-larval toxicity test, RUP proved be more toxic than AKB for mortality endpoint (LC50-96h of 28.23 and 75.33 mg/L, respectively) and GLI (LC50 > 100 mg/L) while for hatching parameter, AKB (EC50-48h of 6.23 mg/L) was more toxic than RUP (EC50-48h of 8.29 mg/L) and GLI exposure did not affect the hatching process. We concluded that active ingredient (GLI), AKB and RUP glyphosate-based formulations are phytotoxic and induce toxic effects in non-target organisms like A. salina and zebrafish early life stage. In addition, our results shows the evaluation necessity of glyphosate-based formulations, once they present different toxic potentials on different organisms. / Herbicidas à base de glifosato são amplamente utilizados em todo o mundo devido à sua eficácia e pelo fato de serem relativamente não-tóxicos para espécies não-alvo. O uso indiscriminado desses praguicidas podem levar a consequências graves em termos de saúde humana e desequilíbrio de ecossistemas. O presente trabalho avaliou a toxicidade aguda do ingrediente ativo (GLI) e duas formulações à base de glifosato, Roundup Original (RUP) e Glifosato de AKB 480 (AKB), em diferentes organismos: sementes de pepino (Cucumis sativus), alface (Lactuca sativa) e tomate (Lycopersicon esculentum), microcrustáceo Artemia salina e fases iniciais de desenvolvimento de zebrafish (Danio rerio). Para o endpoint de germinação, L. esculentum mostrou-se sensível a exposição ao AKB com CE50 de 702,10 mg/L e L. sativa para a exposição ao GLI com CE50 de 612,30 mg/L. No entanto, as três substâncias induziram efeito tóxico significativo no alongamento da raiz de todas as espécies testadas. GLI, RUP e AKB induziram toxicidade significativa para A. salina e foram classificados na Categoria III de acordo com critérios do Sistema Globalmente Harmonizado de Classificação (GHS). No entanto, o RUP (CL50-48h de 39,4 mg/L) foi mais tóxico do que GLI (CL50-48h de 65,24 mg/L) e AKB (CL50-48h de 104,20 mg/L). Para o teste de toxicidade com as fases iniciais de zebrafish, RUP (CL50-96h de 28,23 mg/L) provou ser mais tóxico para o parâmetro de mortalidade do que AKB (CL50-96h de 75,33 mg/L) e GLI (CL50 > 100 mg/L), enquanto que para o endpoint de eclosão, AKB (CE50-48h de 6,23 mg/L) mostrou-se mais tóxico do que o RUP (CE50-48h de 8,29 mg/L) e a exposição GLI não afetou a eclosão das larvas. Concluiu-se que, tanto o ingrediente ativo glifosato, quanto as formulações AKB e RUP foram fitotóxicos para as três espécies de sementes e induziram efeitos tóxicos em organismos não-alvo como A. salina e zebrafish. Além disso, nossos dados apontam para a necessidade de avaliação das diversas formulações a base de glifosato, uma vez que as mesmas apresentam diferentes potenciais tóxicos para diferentes organismos.

La fusariose de l'épi est une maladie grave des cultures céréalières du Québec. Il a été établi que la quantité de résidus de culture laissée par le travail du sol et l'application de glyphosate pouvaient augmenter l'intensité de cette maladie. L'objectif de cette étude était de déterminer l'effet du glyphosate, appliqué sur un précédent cultural de soya, sur l'intensité de la fusariose du blé et de l'orge et la production d'inoculum de Fusarium graminearum selon trois travaux du sol : labour à l'automne, travail réduit du sol au printemps et semis direct. L'expérience a été répétée sur deux années (2007-2008), à deux stations expérimentales localisées au Québec. Généralement, l'application de glyphosate n'a pas influencé significativement l'intensité de la fusariose ou la production d'inoculum de F. graminearum, quel que soit le travail du sol exécuté. En revanche, l'effet du cultivar était fortement significatif. Ce dernier facteur, combiné aux conditions climatiques et à l'inoculum aérien de F. graminearum présent au-dessus des parcelles, serait davantage associé à l'intensité de la maladie que l'application de glyphosate.