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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Glyphosate Tolerance in Roundup Ready Flex Cotton (Gossypium hirsutum)

Huff, Jonathan Andrew 05 May 2007 (has links)
Due to reduced reproductive tolerance, current Roundup Ready cotton only allows for over-the-top glyphosate applications through the fourth leaf stage of development. To combat this issue, Roundup Ready Flex cotton was introduced in 2006, offering both vegetative and reproductive tissue tolerance to glyphosate. Roundup Ready Flex cotton offers a wider window of application timing, without risk of plant injury. The primary objectives of this research were to test Roundup Ready Flex cotton against current Roundup Ready cotton technology at various application rates and timings and to test various elite varieties of Roundup Ready Flex cotton for glyphosate tolerance. Roundup Ready Flex cotton tolerance was unaffected by application rates or timings. Roundup Ready Flex cotton varieties were unaffected by glyphosate applications. Roundup Ready Flex cotton exhibits both vegetative and reproductive tolerance to glyphosate and is an effective alternative to current Roundup Ready cotton cropping systems.
2

Double-crop corn (zea mays) weed control in Virginia

King, Steve Russell 15 May 2000 (has links)
Double-crop production of corn (Zea mays L.) for grain following the harvest of small grain is not currently practiced in Virginia. Historical precipitation and evapotransportation data indicate that delayed corn planting could result in a higher probability of moisture during critical periods of crop development. Double-crop corn may also reduce economic risk as two crops would be harvested in the same year. Field experiments were conducted in three Virginia locations in 1998 and 1999 to determine the herbicide inputs required for double-crop corn production relative to those required in full-season no-till corn production. Experiments were conducted in a split-plot, randomized complete block design with cropping system as the main plot and herbicide treatment as the subplot. Herbicide treatments included combinations of nonselective herbicides for no-till establishment and/or preemergence residual herbicides and/or selective postemergence herbicides in both production systems. Glyphosate-tolerant corn was planted in all experiments and postemergence glyphosate treatments were also evaluated. In each experiment, dependent variables included weed control by species evaluated throughout the season, as well as weed biomass and corn yield evaluated at the end of the growing season. Generally, nonselective herbicides were not required in the double-crop system where atrazine was applied as a preemergence treatment, or where selective postemergence treatments were applied. Where a significant proportion of the infestation was comprised of perennial species, however, atrazine treatments were not sufficient in the double-crop system. Postemergence glyphosate treatments provided excellent broad-spectrum weed control in this situation. In heavy annual grass infestations, postemergence glyphosate treatments provided superior weed control to preemergence treatments alone, and equivalent weed control to treatments in which both preemergence and postemergence herbicides were applied. Corn yield response to weed control and cropping system variables varied significantly between the 1998 and 1999 growing seasons. Where adequate late-season rainfall was received, economic return from small grain and corn crops in the double-crop system was higher than the return in the full-season system, particularly in infestations where the double-crop system allowed significant reduction in herbicide input. / Master of Science
3

APLICAÇÃO DE GLIFOSATO E MANGANÊS NA NUTRIÇÃO E PRODUTIVIDADE DA SOJA TRANSGÊNICA / APLICAÇÃO DE GLIFOSATO E MANGANÊS NA NUTRIÇÃO E PRODUTIVIDADE DA SOJA TRANSGÊNICA / Application glyphosate in transgenic glyphosate-resistant soybean and your effect manganese uptake / Application glyphosate in transgenic glyphosate-resistant soybean and your effect manganese uptake

Stefanello, Fábio Fernando 19 July 2009 (has links)
Made available in DSpace on 2016-02-26T12:59:40Z (GMT). No. of bitstreams: 1 FabioFernandoStefanello.pdf: 387128 bytes, checksum: ab00691ba985715c2d4d480a0eaf642d (MD5) Previous issue date: 2009-07-19 / The transgenic glyphosate-resistant soybean (soybean GR) has been widely cultivated in the world. Although of the benefits of this technology on weed control, currently observed at some regions that, after the application glyphosate, the soybean GR were with leaf chlorosis and could be caused by glyphosate-induced deficiency of Manganese. Thus, the objective of this study was to evaluate the post-emergence application of glyphosate and Mn on soybean GR at different phenological growth stages and your effect in nutrients uptake and soybean GR yield. The experiment was carried out at two farms (Lages de Pedra and São Manoel), both at city of Rio Brilhante-MS. The study was in a completely randomized block design with four (São Manoel) and six (Lages de Pedra) replicates. The treatments were analyzed as factorial 3x8 with three times of application (without glyphosate; glyphosate application (720 g e.a.) in phenological growth stages V2 + V4 (480 g e.a.) and application only V4 (1.200 g e.a.)) and eight foliar Mn application of Mn in different phenological growth stages (without Mn; Mn on V4; Mn on V4 + V8; Mn on V4 + R2; Mn on V4 + V8 + R2; Mn on V8; Mn on V8 + R2 e Mn on R2), completing 24 treatments. It was not observed at no moment of the development of the culture visual symptoms of plant toxicity effects caused by glyphosate application. As well, it was not observed effects of glyphosate application on soybean GR in uptake of Mn and nutrients as N, P, K, Fe, Zn e Cu, as well, in mass of 100 grains and yield culture. The foliar Mn application did not influence the mass of 100 grains and yield culture, however increased leaf Mn content when the application was carried at phenological growth stages V8 and R2 or inside these possible combinations. The leaf Fe content decreased with the foliar Mn application / A soja transgênica resistente ao glifosato tem sido amplamente cultivada no mundo. Apesar dos benefícios dessa tecnologia no controle de plantas daninhas, recentemente tem-sê observado em alguns locais que, após a aplicação de glifosato as plantas de soja RR encontravam-se amarelecidas, e isso poderia ser causado por uma deficiência induzida de Mn. Assim o objetivo deste trabalho foi avaliar a aplicação de glifosato em pós-emergencia em diferentes estádios fenológicos da soja RR e, seus efeitos nos teores foliares de nutrientes e produtividade de grãos, em condições de campo. O experimento foi desenvolvido na Faz. Lages de Pedra e Faz. São Manoel, ambas no município de Rio Brilhante MS. O delineamento experimental foi em blocos casualizados, com quatro e seis repetições nos diferentes locais. Os tratamentos foram dispostos em arranjo fatorial 3 x 8, e consistiram da combinação de três tratamentos com aplicação de glifosato (sem glifosato; 720 g i.a. de glifosato no estádio fenológico da soja V2 + 480 g i.a. em V4 e 1.200 g i.a. de glifosato no estádio V4 da soja RR) e oito tratamentos com aplicação de Mn (sem aplicação de Mn; Mn no estádio fenológico da soja V4; Mn em V4 + V8; Mn em V4 + R2; Mn em V4 + V8 + R2; Mn em V8; Mn em V8 + R2 e Mn no estádio R2 da soja) (em cada aplicação de Mn foi utilizado 332 g de Mn ha-1), totalizando 24 tratamentos. Não foi observado em nenhum momento do desenvolvimento da cultura sintomas visuais de fitotoxidade na soja RR oriundos da aplicação de glifosato. Neste estudo não foi observado efeito do glifosato sobre os teores foliares de Mn na soja RR, assim como dos nutrientes N, P, K, Fe, Zn e Cu, bem como na massa de 100 grãos e na produtividade de grãos da soja. A aplicação foliar com Mn não influenciou a massa de 100 grãos e a produtividade, entretanto aumentou os teores foliares de Mn quando a aplicação foi realizada de forma isolada ou nas possíveis combinações nos estádios fenológicos V8 e R2 da soja transgênica. O teor foliar de Fe diminuiu com a aplicação foliar de Mn na Faz. Lages de Pedra
4

APLICAÇÃO DE GLIFOSATO E MANGANÊS NA NUTRIÇÃO E PRODUTIVIDADE DA SOJA TRANSGÊNICA / APLICAÇÃO DE GLIFOSATO E MANGANÊS NA NUTRIÇÃO E PRODUTIVIDADE DA SOJA TRANSGÊNICA / Application glyphosate in transgenic glyphosate-resistant soybean and your effect manganese uptake / Application glyphosate in transgenic glyphosate-resistant soybean and your effect manganese uptake

Stefanello, Fábio Fernando 19 July 2009 (has links)
Made available in DSpace on 2016-02-26T12:59:20Z (GMT). No. of bitstreams: 1 FabioFernandoStefanello.pdf: 387128 bytes, checksum: ab00691ba985715c2d4d480a0eaf642d (MD5) Previous issue date: 2009-07-19 / The transgenic glyphosate-resistant soybean (soybean GR) has been widely cultivated in the world. Although of the benefits of this technology on weed control, currently observed at some regions that, after the application glyphosate, the soybean GR were with leaf chlorosis and could be caused by glyphosate-induced deficiency of Manganese. Thus, the objective of this study was to evaluate the post-emergence application of glyphosate and Mn on soybean GR at different phenological growth stages and your effect in nutrients uptake and soybean GR yield. The experiment was carried out at two farms (Lages de Pedra and São Manoel), both at city of Rio Brilhante-MS. The study was in a completely randomized block design with four (São Manoel) and six (Lages de Pedra) replicates. The treatments were analyzed as factorial 3x8 with three times of application (without glyphosate; glyphosate application (720 g e.a.) in phenological growth stages V2 + V4 (480 g e.a.) and application only V4 (1.200 g e.a.)) and eight foliar Mn application of Mn in different phenological growth stages (without Mn; Mn on V4; Mn on V4 + V8; Mn on V4 + R2; Mn on V4 + V8 + R2; Mn on V8; Mn on V8 + R2 e Mn on R2), completing 24 treatments. It was not observed at no moment of the development of the culture visual symptoms of plant toxicity effects caused by glyphosate application. As well, it was not observed effects of glyphosate application on soybean GR in uptake of Mn and nutrients as N, P, K, Fe, Zn e Cu, as well, in mass of 100 grains and yield culture. The foliar Mn application did not influence the mass of 100 grains and yield culture, however increased leaf Mn content when the application was carried at phenological growth stages V8 and R2 or inside these possible combinations. The leaf Fe content decreased with the foliar Mn application / A soja transgênica resistente ao glifosato tem sido amplamente cultivada no mundo. Apesar dos benefícios dessa tecnologia no controle de plantas daninhas, recentemente tem-sê observado em alguns locais que, após a aplicação de glifosato as plantas de soja RR encontravam-se amarelecidas, e isso poderia ser causado por uma deficiência induzida de Mn. Assim o objetivo deste trabalho foi avaliar a aplicação de glifosato em pós-emergencia em diferentes estádios fenológicos da soja RR e, seus efeitos nos teores foliares de nutrientes e produtividade de grãos, em condições de campo. O experimento foi desenvolvido na Faz. Lages de Pedra e Faz. São Manoel, ambas no município de Rio Brilhante MS. O delineamento experimental foi em blocos casualizados, com quatro e seis repetições nos diferentes locais. Os tratamentos foram dispostos em arranjo fatorial 3 x 8, e consistiram da combinação de três tratamentos com aplicação de glifosato (sem glifosato; 720 g i.a. de glifosato no estádio fenológico da soja V2 + 480 g i.a. em V4 e 1.200 g i.a. de glifosato no estádio V4 da soja RR) e oito tratamentos com aplicação de Mn (sem aplicação de Mn; Mn no estádio fenológico da soja V4; Mn em V4 + V8; Mn em V4 + R2; Mn em V4 + V8 + R2; Mn em V8; Mn em V8 + R2 e Mn no estádio R2 da soja) (em cada aplicação de Mn foi utilizado 332 g de Mn ha-1), totalizando 24 tratamentos. Não foi observado em nenhum momento do desenvolvimento da cultura sintomas visuais de fitotoxidade na soja RR oriundos da aplicação de glifosato. Neste estudo não foi observado efeito do glifosato sobre os teores foliares de Mn na soja RR, assim como dos nutrientes N, P, K, Fe, Zn e Cu, bem como na massa de 100 grãos e na produtividade de grãos da soja. A aplicação foliar com Mn não influenciou a massa de 100 grãos e a produtividade, entretanto aumentou os teores foliares de Mn quando a aplicação foi realizada de forma isolada ou nas possíveis combinações nos estádios fenológicos V8 e R2 da soja transgênica. O teor foliar de Fe diminuiu com a aplicação foliar de Mn na Faz. Lages de Pedra
5

Vergleich eines neu entwickelten immunologischen Nachweissystems für die gentechnisch veränderten Roundup-Ready-Sojabohnen mit einer DNA-analytischen Methode anhand verschiedener Lebensmittelmatrices

Jansen, Bärbel. Unknown Date (has links) (PDF)
Techn. Universiẗat, Diss., 2003--Berlin.
6

Contested Safety: Monsanto's "Roundup Ready" Agricultural Assemblage versus Counter Discourses of Roundup

January 2015 (has links)
abstract: Genetically Modified Organisms (GMOs) have a polarizing effect in the US. The first commercially viable GMO was Roundup Ready Soy, introduced by Monsanto in 1996, to be used in conjunction with Roundup herbicides. This thesis investigated and delineated the development and deployments of the discourse of Monsanto’s agricultural assemblage of Roundup Ready seeds and Roundup herbicides and its resistant discourses. Monsanto builds its discourse around the safety and necessity of Roundup Ready seeds through federal regulation and toxicology studies. Resistant discourses deployed by Monsanto’s critics problematize Roundup safety and reject Monsanto’s contention that GMOs are necessary for meeting world’s food demands. The discourse analysis pursued in this thesis explored interactions between the dominant discourse and counter discourses and charted their deployments in Colorado’s and Oregon’s 2014 ballot measures that would have required mandatory GMO labeling. Analysis suggested counter discourses were successful in mobilizing people to engage civically. / Dissertation/Thesis / Masters Thesis Communication Studies 2015
7

Manganês e biorregulador em soja RR2 manejada com Glyphosate

Cantú, Carine 27 February 2018 (has links)
Submitted by Helena Bejio (helena.bejio@unioeste.br) on 2018-06-13T00:16:06Z No. of bitstreams: 2 Carine_Cantu_2018.pdf: 977649 bytes, checksum: 41148d5ff61316392a5cc7795d616f39 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-06-13T00:16:06Z (GMT). No. of bitstreams: 2 Carine_Cantu_2018.pdf: 977649 bytes, checksum: 41148d5ff61316392a5cc7795d616f39 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The cultivation of RR (Roundup Ready®) soybean has increased over the past few years and, as a result, changes regarding weed management have been evidenced, with emphasis on the intensification of glyphosate use. However, research results report that in some cases, the herbicide has caused phytotoxic effects on the soybean crop. Thus, the objective of this study was to evaluate the behavior of manganese and of the bioregulator in reversing possible damages caused by glyphosate herbicide in RR soybean. Two experiments were carried out during the 2016/17 crop in Palotina, PR. In the first experiment, the experimental design was a randomized block design in 5 x 4 factorial arrangement with 5 doses of glyphosate (0; 720; 1440; 2160 and 2880 g. e.a. ha-1) and 4 doses of manganese (0; 92,4; 184,8 and 369,6 g ha-1). Glyphosate and manganese were applied together via foliar at V4 stage. The variables evaluated were: chlorophyll index, plant height, insertion height of the first pod, number of pods, 1.000 grain mass and yield. The results showed the glyphosate effect in reducing the number of pods per plant due to the increase of herbicide doses. Regarding the foliar application of Mn, there was an increase in the number of pods per plant and consequently in yield. It was observed that an increase in Mn doses up to 261,64 g Mn ha-1 increased grain yield. In the second experiment, the experimental design was a randomized block design, in 5 x 4 factorial arrangement with 5 doses of glyphosate (0; 720; 1440; 2160 and 2880 g. e.a. ha-1) and 4 management (manganese application; bioregulator application; association of both; no application). The glyphosate, manganese and bioregulator were applied together via foliar at V4 stage. The evaluated variables were phytotoxicity symptoms and others described in the first experiment. Under the environmental conditions of this experiment and for the evaluated genotype, the application of glyphosate in the studied formulation, regardless of the dose used, presented very mild phytotoxicity symptoms in the RR soybean plants and the management applied (bioregulator and Mn) was not effective as phytotoxicant reversers. Therefore, phytotoxicity did not interfere in the evaluated agronomic characteristics and production components. Despite the results verified in these experiments, in general, the cultivar under study showed to be highly tolerant to glyphosate, considering that the herbicide had no effect on the vegetative and reproductive development of soybean plants to the point of reducing grain yield. It is highlighted the need for additional studies in order to evaluate other genotypes, locations and years/crop and to reassess the potential of using manganese and bioregulator in the management with glyphosate in RR2 soybean. / O cultivo da soja RR (Roundup Ready®) tem aumentado nos últimos anos, e em decorrência disso, mudanças no manejo das plantas daninhas têm sido evidenciadas, com destaque à intensificação do uso de glyphosate. Porém, relatos de agricultores apontam que em alguns casos o herbicida tem causado efeitos fitotóxicos na cultura da soja. Assim, o presente trabalho teve como objetivo avaliar o comportamento do manganês (Mn) e do biorregulador na reversão dos possíveis danos causados pelo herbicida glyphosate na soja RR. Foram realizados dois experimentos na safra 2016/17 no município de Palotina, PR. No primeiro experimento o delineamento experimental utilizado foi o de blocos casualizados, em arranjo fatorial 5 x 4, sendo cinco doses de glyphosate (0; 720; 1440; 2160 e 2880 g. e.a. ha-1) e quatro doses de manganês (0; 92,4; 184,8 e 369,6 g ha-1). O glyphosate e o manganês foram aplicados em conjunto via foliar no estádio V4. As variáveis avaliadas foram: índice de clorofila, altura de plantas, altura de inserção da primeira vagem, número de vagens por planta, massa de mil grãos e produtividade. Os resultados obtidos demostraram efeito do glyphosate na redução do número de vagens por planta em função do aumento das doses do herbicida. Em relação à aplicação foliar de Mn, houve aumento do número de vagens por planta e da produtividade de grãos, verificando-se que o incremento das doses de Mn até a dose estimada de 261,64 g Mn ha-1, proporcionou aumento da produtividade. No segundo experimento o delineamento experimental utilizado foi o de blocos casualizados, em arranjo fatorial 5 x 4, sendo cinco doses de glyphosate (0, 720, 1440, 2160 e 2880 g. e.a. ha-1) e quatro manejos (aplicação de manganês; aplicação de biorregulador; associação de ambos; sem aplicação). O glyphosate, manganês e o biorregulador foram aplicados em conjunto via foliar no estádio V4. As variáveis avaliadas foram sintomas de fitointoxicação e as demais descritas no primeiro experimento. Nas condições ambientais deste experimento e para o genótipo avaliado, a aplicação de glyphosate na formulação estudada, independente da dose utilizada, apresentou sintomas de fitointoxicação nas plantas de soja RR e os manejos empregados (biorregulador e Mn) não se mostraram efetivamente como reversores da fitointoxicação. Portanto, a fitointoxicação não interferiu nas características agronômicas e nos componentes de produção avaliados. Apesar dos resultados verificados nesses experimentos, de modo geral a cultivar em estudo se mostrou altamente tolerante ao glyphosate, visto que, o herbicida não apresentou efeito no desenvolvimento vegetativo e reprodutivo das plantas de soja de tal modo a reduzir a produtividade de grãos. Ressalta-se a necessidade de estudos adicionais com o intuito de avaliar outros genótipos, locais e anos/safra de cultivo a fim de reavaliar o potencial de utilização do manganês e biorregulador no manejo com o glyphosate em soja soja RR2.
8

Environmentálně-ekonomická hlediska pěstování vybraných geneticky modifikovaných plodin v Evropské unii

Ševčík, Michal January 2017 (has links)
ŠEVČÍK, M. Environmental-economic aspects of cultivation of selected genetically modified plants in European Union. Diploma thesis. Mendel University in Brno. Faculty of Regional Development and International Studies, 2017. This diploma thesis deals with the topic of cultivation of selected genetically modified crops in the EU. Literature part describes population development and food production in Europe after the Industrial Revolution, while the other parts are focused on the mechanism of genetic modification of crops, the potential impacts of their cultivation, as well as the perception of this issue in the public and interest groups followed by description of the past and current state of GM crop cultivation in the EU, with particular emphasis on the legislative and institutional framework of the issue. The literature part is concluded by comparison of the environmental and economic impacts of growing MON810 maize on the territory of the Czech Republic, Poland and Slovakia, and a subchapter on the potential benefits of growing Roundup Ready Soy in the EU. The practical part of the thesis presents the results of a one-year soybean experiment with the aim of finding the optimum types and dose of fertilizers for the highest yield and nutritional value of the seed. On the basis of these results, the author of the thesis then estimates the potential of introducing genetically modified soybean - Roundup Ready variety, in EU.
9

Perceptions of Validity: How Knowledge is Created, Transformed and Used in Bio-Agricultural Technology Safety Testing for the Development of Government Policies and Regulations

Josephs, Jennifer 01 January 2017 (has links)
This is a case study dissertation to research the socio-political conflict surrounding Gilles Eric Séralini’s et al (2012) research on the toxicity of Monsanto’s NK603 line of corn and the herbicide Roundup. The study analyzes this conflict as a system of interconnected and often conflicting interests, assumptions and ideologies about how knowledge is created and transformed from the research stage to the policy implementation stage. The goal of this study is to: 1.) analyze critical surface level and underlying factors that contribute to the conflict; 2.) analyze systemic processes between national and international researchers, private interests and government policymakers in developing and implementing research protocols, policies and regulations pertaining (but not limited) to Monsanto’s NK603 corn and Roundup; 3.) identify potential patterns of knowledge transformation from the research stage to policy implementation. The theoretical approach used in this study considers social construction, critical theory and Kuhn’s theory of scientific revolution. In utilizing case study methodology, this study incorporates internal analysis of Séralini’s case with a basic comparative analysis of DDT and lead policy processes and knowledge transformation, using mainly secondary data sources supplemented with primary interview material from two select researchers using purposive sampling. By conducting this research, it is hoped that this study reveals a better understanding of the complex interconnected systems that help create and transform food safety policies and the science that supports and/or transforms them.
10

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

Pline, Wendy Ann 07 May 1999 (has links)
The introduction of herbicide resistant crops offers producers many more options for weed control systems. These crops allow environmentally safe, non-selective herbicides to be used as selective herbicides, broadening the spectrum of weeds controlled, while not harming the crop. As these crops are very new on the market, investigation of their performance under various environmental conditions as well as in various weed control programs is needed. Liberty-link ® soybeans are resistant to the herbicide glufosinate, because of the incorporation of a gene encoding phosphinothricin acetyl-transferase (pat), which is able to detoxify glufosinate. Roundup-Ready ® soybeans are transformed with an altered, non-sensitive form of 5-enolpyruvylshikimate- 3-phosphate synthase (EPSPS), which confers glyphosate resistance. Field and greenhouse studies were conducted to determine the efficacy of glufosinate and glyphosate on annual and perennial weeds. Also to determine whether the use of ammonium sulfate (AMS) or pelargonic acid (PA), a 9-carbon fatty acid, as additives of glufosinate or glyphosate would increase their efficacy, while maintaining their safety on the transgenic soybeans. Three annual weeds: common lambsquarters, giant foxtail, sicklepod, as well as two perennial weeds: common milkweed and horsenettle were included in studies. Uptake, translocation, and metabolism of 14C-glufosinate + AMS or PA, were studied in the five weeds in order to determine the basis for their differential weed sensitivity to glufosinate, and the effect of the two additives. The effect of temperature on Liberty-Link ® and Roundup-Ready ® soybeans after application of glufosinate or glyphosate was investigated. Injury was quantified by measuring chlorophyll content of herbicide treated soybean trifoliolates. Uptake, translocation, and metabolism studies of 14C-glufosinate and 14C-glyphosate in transgenic soybeans were conducted to determine the potential cause for the observed temperature-dependent sensitivity. Since glufosinate is a synthetic analog of a naturally occurring bacterial toxin, it was tested for possible bactericidal activity on the soybean pathogen Pseudomonas syringae. Greenhouse and field-studies showed that the 5 weeds responded differently to glufosinate and glyphosate. Common milkweed was the most tolerant to glufosinate and common lambsquarters to glyphosate while giant foxtail was the most sensitive species to both herbicides. Some interactions between AMS or PA and glufosinate or glyphosate were also observed. Uptake and translocation studies showed that AMS increased the uptake of 14C-glufosinate in some weeds, whereas PA had only minimal effects on absorption and translocation of glufosinate. Metabolism of glufosinate was detected only in common lambsquarters. A rate dependent loss of chlorophyll in Liberty-Link ® soybeans treated with glufosinate was observed that was greater at 15° C than at 25° or 35° C. Metabolism studies showed a decrease in the rate of glufosinate metabolism 3 hours after treatment in Liberty-Link ® soybeans grown at 15° C versus 25° C. Conversely, chlorophyll loss in glyphosate-treated Roundup-Ready soybeans was greater at 35° C than at 15° or 25° C. Translocation studies showed a significantly greater percentage of absorbed 14C-glyphosate translocated to developing meristems at 35° C than at 15° C in Roundup-Ready® soybeans. Glufosinate concentrations of 1 mM and higher significantly inhibited the growth of Pseudomonas syringae (L-529) in liquid media cultures. Typical field use rates of glufosinate also reduced the number of live P. syringae on Liberty-Link® soybean leaves. Overall, the results of this research show that annual and perennial weeds differ in their sensitivity to glufosinate and glyphosate. Additives such as AMS and PA may enhance the efficacy of glufosinate on perennial weed species, and glyphosate in most weeds. Differences in weed sensitivity to herbicides and effects of additives can in most cases be explained by differences in absorption or metabolism. Variable temperatures may affect the engineered resistance of transgenic soybeans to the herbicides glufosinate and glyphosate. The herbicide glufosinate has some bacteriocidal activity on P. syringae. Nomenclature: Glufosinate, 2-amino-4-(hydroxymethylphosphinyl) butanoic acid; Glyphosate, N-(phosphonomethyl)glycine; PA, pelargonic acid (nanoic acid); AMS, ammonium sulfate; giant foxtail, Setaria faberi Herrm.; common lambsquarters, Chenopodium album L.; sicklepod, Cassia obtusifolia L.; horsenettle, Solanum carolinense L.; common milkweed, Ascleipias syriaca L. pat, phosphinothricin acetyl transferase; EPSPS, 5-enolpyruvylshikimate-3-phosphate synthase. / Master of Science

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