Dissertations / Theses on the topic 'Glyphosate'

Studies were conducted to determine the optimum time to apply glyphosate to glyphosate-tolerant Lactuca sativa cv. Raider (head lettuce). The study was initiated near Yuma, Arizona in September 2000. Single applications of glyphosate at 1.0 lb AI/A were made to head lettuce at development stages of 2, 4, 6 and 8 leaves. Glyphosate treatments did not injure lettuce. A single application at the 2 or 4 leaf stage was optimal for near complete control of Portulaca oleracea (common purslane), Chenopodium murale (nettleleaf goosefoot), Malva parviflora (cheeseweed), and Leptochloa spp. (sprangletop). Later applications at the 6 or 8 leaf stages allowed weeds, especially, common purslane to compete with the crop. Treatments applied at the 2 or 4 leaf stages required the least amount of time to hand weed and resulted in highest fresh weight yields.

Glyphosate (N-phosphonomethylglycine) is an organophosphate compound which was developed by the Monsanto Company in 1971 and is the active ingredient found in several herbicide formulations. The use of glyphosate-based herbicides in South Africa for the control of alien invasive plants and weeds is well established, extensive and currently unregulated, which vastly increases the likelihood of glyphosate contamination in environmental water systems. Although the use of glyphosate-based herbicides is required for economic enhancement in industries such as agriculture, the presence of this compound in natural water systems presents a potential risk to human health. Glyphosate and glyphosate formulations were previously considered safe, however their toxicity has become a major focal point of research over recent years. The lack of monitoring protocols for pesticides in South Africa is primarily due to limited financial capacity and the lack of analytical techniques.

Doctor of Philosophy
Department of Agronomy
Phillip W. Stahlman
Kochia [Kochia scoparia (L.) Schrad.] is a weed of great economic importance in the Great Plains and western United States and Canada. This weed is prone to evolving resistance to herbicides. Glyphosate is the most widely used herbicide in glyphosate-resistant crops and chemical fallow, and is extremely valuable to crop production. Anecdotal reports of kochia control failure with glyphosate in western Kansas arose during the mid-2000’s. The objectives of this research were to (1) confirm and characterize glyphosate resistance in kochia and measure its impact in western Kansas, (2) gather information on grower weed management practices before and since glyphosate resistance in kochia was confirmed, and (3) determine if altered absorption and translocation of glyphosate contributes to glyphosate resistance in kochia. Dose-response studies on greenhouse and outdoor grown plants, and shikimate accumulation assays confirmed one kochia population collected in 2007 and eight populations collected in 2010 tolerated three- to eleven-times more glyphosate compared to a known glyphosate-susceptible (GS) population. Furthermore, 40 kochia populations collected in 2012 showed varied response, from slightly elevated tolerance to resistance to 0.84 kg ae ha-1 glyphosate. Further analysis suggested these populations were at different stages of resistance evolution. An online survey revealed that growers increased glyphosate use rate and application frequency, but decreased exclusive use of glyphosate and diversified weed management practices during post- compared to pre-glyphosate confirmation periods. Most survey respondents reported presence of glyphosate-resistant (GR) kochia in at least in few fields, and half reported GR kochia in a majority of fields. Thus, together with the resistance confirmation studies, it is estimated that at least one-third of western Kansas kochia populations have evolved resistance to glyphosate. Nominal differences in absorption and translocation of 14C-glyphosate observed between GS and GR kochia populations likely do not contribute to differential response of these populations to glyphosate. Glyphosate-resistant kochia has become widespread in western Kansas in a short period of time. Use of weed resistance best management practices (BMP) is imperative to sustain the utility of glyphosate in the region.

Transgenic, glyphosate-resistant (GR) cotton has been available to U.S. growers since 1997. Despitewide-spread acceptance, there have been performance complaints by growers citing lower boll retention in GRvarieties than in conventional varieties. Field and greenhouse studies confirmed grower observations,demonstrating a glyphosate-associated decrease in boll retention compared to non-treated GR or conventionalplants. Late (beyond the 5 leaf stage) foliar applications were the most injurious, presumably because plantswere entering early reproductive stages. Boll ?cavitation,? (dessicated bolls attached to plants) also observed bygrowers following glyphosate treatment, resulted from abnormal abscission zone formation and was related tovariety.

14C-glyphosate absorption per square centimeter was greater when applied to stem tissue than leaf tissue, but overallabsorption is likely greater when applied foliarly, due to a greater total surface area. Because glyphosatetypically moves from source tissue to sink tissue, up to 3.7% of applied 14C-glyphosate was translocated toreproductive tissues.

Seedling development in both GR and conventional cotton was inhibited by root-absorbed glyphosate.Root tissues were more sensitive to glyphosate than cotyledons or hypocotyls, as was demonstrated byinhibition of lateral root formation and shikimic acid accumulation. CP4-EPSPS content was significantly lowerin GR seedling roots than cotyledons, accounting for glyphosate sensitivity.

Further studies compared the accumulation of shikimic acid in response to glyphosate in reproductiveand vegetative tissues in GR and conventional cotton. Shikimic acid accumulation per mM of glyphosate, wasgreater in reproductive than vegetative leaf tissue in both GR and conventional cotton, suggesting thatreproductive tissue is innately more sensitive to glyphosate than vegetative tissue. The quantity of theglyphosate-resistant CP4-EPSPS enzyme was significantly less in stamens than in vegetative leaf tissues.Several morphological differences were apparent in flowers of glyphosate-treated GR cotton.

Glyphosate applications inhibited stamen elongation, resulting in anthers not extending to the tip of the stigma,thereby limiting pollen deposition to the lower, less receptive portion of the stigma. Total pollen deposition on the stigma was less in glyphosate-treated GR cotton than non-treated GR or conventional cotton. Microscopicanalysis of pollen revealed that glyphosate arrested maturation in at least 3 pollen developmental stages. Atanthesis, pollen grains from glyphosate-treated GR plants were collapsed, highly vacuolated, and had 60% lowerviability (ability to germinate) than pollen from non-treated GR or conventional plants. Retained bolls fromglyphosate-treated plants had fewer seeds than those from non-treated GR or conventional plants. Hand crossesbetween glyphosate-treated plants demonstrated that the number of seeds per boll was decreased when the maleparent, but not the female parent, was glyphosate treated. Hand pollinations using pollen from treated plants,although overcoming the increased anther-stigma distance, did not restore the normal number of seeds per boll.Treatment of GA onto glyphosate-treated GR plants did not remediate glyphosate effects on pollen viability andfloral morphology. Therefore, presumably, several of the bolls that were shed due to glyphosate-treatments,contained an insufficient number of fertilized ovules and are thus shed.

This research proposes that boll shed due to glyphosate in GR cotton is due to insufficient levels ofCP4-EPSPS in stamens, which are highly sensitive to glyphosate. As glyphosate accumulates in reproductivestructures, stamen elongation and pollen development are inhibited, resulting in poor fertilization of ovules.Because fewer ovules are fertilized, bolls are either shed or contain fewer seeds if retained. Growers shouldlimit glyphosate contact with GR cotton, especially during the reproductive stages in order to minimize thepotential for glyphosate-induced boll shed.

A field study was conducted in Yuma, Arizona during the late fall 2001 growing season to determine the optimum postemergence (POST) timing of glyphosate application on glyphosate- tolerant Lactuca sativa (head lettuce) for weed control. Head lettuce cv. Raider demonstrated excellent tolerance and no injury was observed on the crop after any glyphosate application at the 2, 4, 6, or 8 leaf stage of growth. A single application of glyphosate at 1.0 lb AI/A at the 4 or 6 leaf stage of lettuce growth was optimal for providing near complete control of Portulaca oleracea (common purslane), Chenopodium album (common lambsquarters), C. murale (nettleleaf goosefoot), Physalis wrightii (Wright’s groundcherry), volunteer cantaloupe (Cucumis melo), and Echinochloa colonum (junglerice). An early application at the 2 leaf stage resulted in few new weeds emerging after the application. A later application at the 8 leaf stage resulted in reduced yields of lettuce fresh weight due to weed competition. POST applications of glyphosate on lettuce offered superior weed control compared to soil-applied preemergence (PREE) herbicide treatments.

The expression of glyphosate resistance can vary within single field populations of common waterhemp and Palmer amaranth. This variability in expression can translate into control ranging from 20 to 80%, which could be the difference in a minor versus a major failure in weed management. Certain application parameters that have been previously associated with glyphosate efficacy, such as glyphosate application time of day and plant stress may exacerbate this variability and lead to failed control of plants on the lower end of the resistance spectrum. Greenhouse research was conducted in 2011 to determine the influence of glyphosate application time of day on the expression of resistance in common waterhemp and Palmer amaranth. Control of both glyphosate-susceptible (GS) and -resistant (GR) weed species showed similar trends in response to glyphosate with respect time of application. Decreased sensitivity of all Amaranthus biotypes was greatest at 9:00 pm and may be attributed to an observed shift in leaf orientation from horizontal to vertical at the time of glyphosate application in response to low-light conditions. The altered leaf orientation most likely reduced herbicide spray coverage. The magnitude of resistance, the difference in the sensitivity of the resistant versus susceptible biotypes, was unaffected by glyphosate application time of day; however, these results indicate that even in resistant populations glyphosate applied at suboptimal times of day such as the evening can cause a further increase in weed escapes from glyphosate. Greenhouse and field experiments were conducted in 2011 and 2012 to determine the influence the soil nutrient amendments on glyphosate sensitivity and growth rate and of GS and GR common waterhemp and Palmer amaranth. In both the GR and GS biotypes of common waterhemp the sensitivity to glyphosate was increased as fertilizer was introduced. However, only the sensitivity of the susceptible biotype of Palmer amaranth was increased with the addition of fertilizer. The lack of response in the GR Palmer amaranth population to fertilizer can be associated with the fact that due to carrier volume limitations enough glyphosate could not be applied to achieve 50% control. The magnitude of resistance was decreased numerically with the addition of fertilizer in both weed species; however, only in common waterhemp was the magnitude of resistance significantly different with the use of high rates fertilizer. The use of fertilizer also had an influence on the growth rate and dormancy of axillary buds. Lateral branching (broken dormancy in axillary buds) was increased in both common waterhemp and Palmer amaranth with the addition of fertilizer. Converting dormant buds to active meristems favors glyphosate translocation and could be responsible for increased glyphosate efficacy. In the field, glyphosate efficacy in GR common waterhemp and Palmer amaranth was also increased with addition of fertilizer; however, this effect was variable. Optimizing the efficacy of glyphosate when applied to even mixed populations of GS and GR Palmer amaranth and common waterhemp can reduce surviving weeds that can produce seed and perpetuate the frequency of glyphosate resistance in the field. Furthermore, greater efficacy of glyphosate may translate into relatively less significant failures in glyphosate applications allowing for successful rescue herbicide treatments and minimal impact on crop yield compared with a complete glyphosate failure with dramatic implications on reduced crop yield and increased weed seed production.

Master of Science
Department of Agronomy
Kassim Al-Khatib
Kochia (Kochia scoparia (L.) Schrad) is a troublesome weed throughout the western United States and Great Plains. It is an aggressive warm season annual dicot plant that exhibits protogynous flowering and facultative open pollination. The aggressive growth habit and prolific seed production enable kochia to spread and compete well for light, moisture, and nutrients. Kochia is ranked as one of the most problematic weeds in cultivated fields including corn, sorghum, wheat, soybean, and sugarbeet. Kochia has been found to lower yields as well as hinder mechanical harvest. Glyphosate is a nonselective herbicide that is widely used in controlling kochia in no-till cropping systems. With rapid adoption of no-till systems where glyphosate is used for weed burndown treatment before planting and extensive use of glyphosate resistant crops, it is common that glyphosate is frequently applied on the same field during the growing season. In 2007, poor control of kochia was observed in three fields in Western Kansas. Greenhouse experiments were conducted with 10 kochia populations to determine the efficacy of glyphosate on kochia when applied at 10 different rates and at 3 plant heights. Herbicide rates included 0, 0.0625, 0.125, 0.25, 0.50, 1, 1.5, 2, 4 and 6 times a typical use rate of 870 g ae/ha. Resistance to glyphosate was identified in three kochia populations. The glyphosate resistant populations from Ingalls, Norton, and Moscow Kansas were 4.6, 3.3, and 2.8 times more resistant to glyphosate than a susceptible population, respectively, based on the rate required for 50% control. Glyphosate injury symptoms included stunting, and chlorosis, followed by some necrotic tissue but resistant plants generally recovered from injury, or were slow to show symptoms. In general, the level of resistance is greater in more developed plants compared to younger plants. Experiments also were conducted on the different kochia biotypes to evaluate glyphosate absorption and translocation, and any differences in mineral content of the plants that might be detrimental to glyphosate activity. Differences in glyphosate absorption and translocation and kochia mineral content were not sufficient to explain the resistance to glyphosate.

Glyphosate (N-(phosphonomethyl)glycine) is the phytotoxic reagent in the widely used Roundup® herbicide. Its mode of action in plants is the disruption of the Shikimate pathway, part of an important route to the biosynthesis of essential aromatic amino acids. It is well documented that glyphosate can be degraded by soil microorganisms after contact of the herbicide solution with the soil. It is also accepted that glyphosate, an excellent ligand, is readily absorbed to metal ions, such as Fe(III), that can be abundant in soils. There have been many accounts on the microbial degradation of glyphosate, and several metal-glyphosate complexes have been synthesised and characterised. Surprisingly, given the degree of adsorption to metal ions in the soil, there have not, to date, been any reports in the literature on the reactivity of metal-glyphosate complexes. The behaviour of these types of complexes under various reaction conditions may give us an insight into the mechanisms present when glyphosate degrades. In order to explore the behaviour of metal-glyphosate adducts, we have prepared several new cobalt-PMG complexes in the lab. These complexes have been characterised by NMR, mass spectrometry, elemental analysis, and in some cases X-ray crystal structure determination. We chose to synthesise complexes where the PMG ligand is bidentate or tridentate, filling the remaining four or three (respectively) coordination sites with an ancillary, nitrogen-containing ligand. We have subjected the complexes to photolytic and basic conditions, as we are interested in ascertaining how coordinated PMG might behave when irradiated with UV light, and when it is C-deprotonated. Metal-glyphosate complexes in nature may be exposed to UV light, so we are concerned with how the coordinated ligand might react under these circumstances. We have found that the prepared cobalt-PMG complexes are reactive when exposed to UV light, and that this appears to result in the degradation of the complex, and in some cases, the PMG ligand itself. The reactivity of C-deprotonated PMG is also an area of interest to us. It is possible that elevations in soil pH can lead to C-deprotonation of glyphosate, then further reactivity that may contribute to the degradation of the compound. Furthermore, when the herbicide is held in the active site of an enzyme within a microbe, it may become deprotonated, and this may aid in its microbial degradation. We have found that, under basic conditions, the reactivity of the prepared PMG complexes depends on the ancillary ligand attached - π-acidic, pyridine-containing ancillary ligands appear to increase the reactivity of coordinated PMG. It seems that amine-containing ligands hinder the reactivity of the coordinated PMG such that the complex remains intact. It is hoped that the results of the research described in this thesis will assist in the future investigations into the reactivity of the herbicide glyphosate.

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Atualmente, tanto no setor de produção agrícola quanto nas diversas áreas da saúde humana, o efeito de subdoses de produtos aplicados, denominado como hormótico, vem sendo amplamente discutido e pesquisado, com o objetivo de compreender o mecanismo de ação estimulante e benéfica de diversas substâncias inicialmente consideradas como tóxicas, quando aplicadas em doses elevadas. O objetivo desta pesquisa foi verificar o efeito hormótico da subdose do herbicida glyphosate nas variáveis morfológicas, fisiológicas e a produção final de cana-de-açúcar. Os experimentos foram plantados em novembro de 2010 na Unidade de Pesquisa e Desenvolvimento de Jaú, SP, da APTA Pólo Centro-Oeste/SAA, conduzidos e avaliados durante o ciclo de cana-de-ano em cana-planta. A variedade utilizada foi a SP80-1842. Os tratamentos foram constituídos pela aplicação ou não de subdose de glyphosate. A aplicação dos tratamentos foi aos 70 dias após o plantio (DAP) e a subdose utilizada foi de 1,8 g e a ha-1 de glyphosate. No primeiro experimento foi avaliado o crescimento e desenvolvimento da cultura da cana-de-açúcar em parcelas de três linhas de plantio por três metros, nas quais foram coletadas um metro linear para avaliações em oito épocas, isto é, 70, 105, 140, 175, 210, 245, 280 e 315 dias após o plantio, em um delineamento de blocos casualizados com seis repetições. No segundo experimento, avaliou-se produtividade de colmos e de açúcar, foram utilizadas parcelas de cinco linhas de plantio por oito metros foram dispostas blocos casualizados com seis repetições, e coletadas ao final do ciclo da cultura, ou seja, aos 315 DAP. Em cada época de amostragem, do primeiro experimento, foram avaliados conteúdo de ácido chiquímico, ácido quínico, glyphosate e ácido aminometilfosfônico, teores de ...
Currently, both in agricultural production and in areas of human health sector, the low dose effect of products applied, termed as hormetic, has been widely debated and researched in order to understand the mechanism of stimulating and beneficial action of several substances initially considered as toxic, when applied in high doses. The objective of this research was to investigate the effect of low dose of glyphosate on growth, phosphorus accumulation in the shoot, the production of shikimic and quinic acid, and final yield of sugarcane. The experiments were planted on November 05, 2010 in Research and Development Unit of Jaú, SP, APTA Polo Midwest / SAA, and carried out and evaluated over the course of the year in sugarcane plant cane. The variety used was SP80-1842. Two experiments were carried out to evaluate the effect hormetic during growth and development of sugarcane and cane yield and sugar. The treatments consisted at application or not of low dose of glyphosate. The spraying was at 70 DAP and the low dose dose used was 1.8 g a e ha-1 glyphosate. In the first experiment evaluated the growth and development of the sugar cane crop in portions of three planting rows of three meters, in which it was collected a linear meter for evaluations in eight times, or , 70, 105, 140, 175, 210, 245, 280 and 315 days after planting, in a randomized block design with six replications. In the second experiment, productivity was evaluated of stalks and sugar, plots were used in five plant lines by eight meters were willing randomized block design with six replications, and collected at the end of the cycle, or, to 315 DAP. At each sampling time, the first experiment examined content of shikimic acid, quinic acid ...

A photolytic cell system suitable for the treatment of wastewater streams containing three pesticides, i) acephate, ii) glyphosate and iii) malathion is reported. The system is capable of destroying these three organic compounds, commonly present in wastewater streams originating from agrochemical industries in Malaysia, and can lead to complete mineralisation under the optimum conditions. The system is based on an advanced oxidation process and involves the production of hydroxyl free radicals in the presence of a UV source. The performance of the system, for the three pesticides, was optimised by investigating the effects of i) UV source, ii) pH of the solution, iii) initial concentration of the substrate, iv) addition of oxidants, v) hydrogen peroxide (H2O2) in the presence and absence of single and mixed metal ions. To monitor the degradation efficiency of the system, the residual concentrations of these organic compounds and metal ions were analysed using five analytical techniques i) total organic carbon (TOC), ii) high performance liquid chromatography (HPLC), iii) ion chromatography (IC), iv) UV/Visible spectroscopy (UV/Vis), and v) atomic absorption spectroscopy (AAS). The data show that the developed photolytic cell system is capable of achieving complete mineralisation of the three pesticides with the use of both 400 W and 600 W UV lamps. However, the 400W UV lamp was used, for economic reasons, to optimise the system for the remaining factors. Changes in the pH of aqueous solutions influenced the degradation efficiency and a complete degradation of the three pesticides was achieved at their self-pH values ranging from 5.0-5.5. The degradation of acephate increased and malathion decreased at their higher initial concentrations whereas no significant effect related to concentration was observed for glyphosate. Results show that the degradation followed a first order kinetics and the degradation rates were: malathion > acephate > glyphosate. The addition of 30 mg/L of H2O2 enhanced the degradation of the pesticides and after 5 hours irradiation these were 95.7%, 91.5% and 81.3% for malathion, acephate and glyphosate respectively. The presence of metal ions was observed to affect degradation (Table 1). With 5.0 mg/L of Fe(II) the degradation of all three pesticides increased, and in all cases acephate removal was improved. Removal of both malathion and glyphosate was negatively affected by copper, an effect that work with mixtures indicated was stronger than the positive effect of iron. The addition of H2O2, in the presence of single metal ions, increases the degradation. However, the addition of H2O2, in the presence of mixed metal ions, has no significant effect on the degradation of glyphosate and malathion. The effect of mixed metal ions on the three pesticides and the effect of Zn(II) ions on acephate and malathion are reported for the first time in this thesis. The developed photolytic cell system can be used for the treatment of wastewater streams originating from point sources, for example, agrochemical industries, under the optimum conditions. The synergistic combination of the developed system with the existing standard technologies is also proposed for the treatment of surface water at water treatment facilities in Malaysia. The application of the developed system can also be extended, with minimum modifications, for the treatment of wastewater streams originating from different manufacturing industries in Malaysia, for example, textile, paper/pulp, printing, coke, petroleum, paint, solvent, pharmaceuticals and wood-preserving chemicals. All these industries produce wastewater streams containing low concentrations of organic pollutants and heavy metal ions.

Master of Science
Department of Agronomy
Mithila Jugulam
Extensive, often exclusive, use of glyphosate in crop production has resulted in evolved glyphosate resistance in several weed species globally. Kochia is a competitive summer annual weed, well adapted to the North American Great Plains and has recently evolved resistance to glyphosate by gene amplification of 5-enolpyruvyl shikimate 3-phosphate synthase (EPSPS), the target-site of glyphosate. The overall objective of this research was to investigate the genetic basis of glyphosate resistance in kochia, specifically to study 1) the inheritance of glyphosate resistance and 2) determine the chromosomal distribution of EPSPS gene copies. Homozygous resistant (R) and susceptible (S) parental lines of kochia were identified. Using these parents, reciprocal crosses were performed to produce F₁ progeny. As expected for a nuclear encoded EPSPS gene, F₁ plants from both crosses survived various doses of glyphosate application. However, F1 plants showed intermediate shikimate accumulation and EPSPS gene copies (relative to ALS reference gene) compared to parents. F₂ progeny were produced by selfing F₁ plants. In response to 870 g ae ha⁻¹ glyphosate, F₂ plants (n=115) segregated into 3:1 (R:S) implying a Mendelian monogenic segregation of glyphosate resistance in kochia. Additionally, relative EPSPS gene copies ranged from 1-10 in the F₂ progeny (n=51) with a genotypic segregation of 40:11 (plants with 3 or more EPSPS gene copies: plants with 1 EPSPS gene copy). In F₂ dose-response, a correlation between the level of resistance and relative EPSPS gene copies was observed. Genomic organization of the amplified copies using fluorescent in situ hybridization (FISH) displayed a single and larger hybridization site of the EPSPS gene on one pair of homologous chromosomes in R compared to a faint hybridization site in S samples of kochia. These results suggest possibility of amplification of EPSPS gene mediated via unequal recombination leading to the evolution of the glyphosate resistance in kochia.

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O eucalipto é a espécie florestal mais utilizada em reflorestamento no país, em virtude do rápido crescimento das plantas, condições climáticas e tecnologias desenvolvidas. Porém, a interferência das plantas daninhas causa grandes prejuízos, decréscimo quantitativo e qualitativo da produção do eucalipto. Entre as possibilidades de manejo de plantas daninhas, o método químico é o mais utilizado, porém, poucos são os herbicidas registrados para a cultura do eucalipto, entre os quais o glyphosate é o mais usado por controlar um grande número de espécies. Existem poucos trabalhos a respeito dos efeitos diretos e indiretos do glyphosate nesta espécie florestal. Neste trabalho, clones de eucalipto urograndis foram submetidos ao contato direto com o glyphosate e indireto por meio de aplicação sobre plantas de Brachiaria decumbens, visando caracterizar o movimento do herbicida, exsudação radicular e seus efeitos na planta. Foram realizadas avaliações de intoxicação visual do eucalipto aos 7, 14 e 21 DAA e da massa da matéria seca das plantas aos 21 DAA. Também foram realizadas quantificações por cromatografia líquida de alta eficiência e espectrometria de massas (LC-MS/MS) em diferentes partes das plantas (superior e inferior) dos seguintes compostos: glyphosate, ácido amimetilfofônico (AMPA), ácido chiquímico, chiquimato-3-fosfato, fenilalanina, tirosina e triptofano. O glyphosate foi detectado nas plantas de eucalipto para os tratamentos com a aplicação direta e indireta do herbicida e houve translocação para os locais que não foram atingidos na aplicação, mesmo quando aplicado sobre a B. decumbens, entretanto o AMPA não foi. A presença de glyphosate nas plantas influenciou na alteração dos níveis de ácido chiquímico, fenilalanina, tirosina, triptofano e chiquimato-3-fosfato, além de causar níveis de intoxicação nas plantas de eucalipto e redução de ...
Eucalyptus is the most used forest species in reforestation in the country due to the rapid growth of plants, climatic conditions and developed technologies. However, interference by the weeds cause major damage, the quantitative and qualitative decrease in production of eucalyptus. Among the weed management possibilities, the chemical method is the most used, however, there are few herbicides registered for eucalyptus cultivation, in which glyphosate is most commonly used to control a large number of species. There are few studies regarding the direct and indirect effects of the glyphosate on this forest species. In this paper, Eucalyptus urograndis clones were subjected to direct contact with glyphosate and indirectly through application on Brachiaria decumbens plants, aiming to characterize the movement of the herbicide, root exudation and its effects on the plant. Visual evaluations were carried out through eucalyptus phytointoxication at 7, 14 and 21 DAA and of the dry mass of the plants at 21 DAA. Also, measurements were made on different parts of plants (top and bottom) of the following compounds by high-performance liquid chromatography and mass spectrometry (LC-MS / MS): glyphosate, aminomethylphosphonic acid (AMPA), shikimic acid, shikimate-3-phosphate, phenylalanine, tyrosine and tryptophan. Glyphosate was detected in eucalyptus plants for treatments with the direct and indirect application of herbicide and there was a translocation to sites that were not attain in the application, even when applied to the B. decumbens, however the AMPA was not. The presence of glyphosate on plants, influenced the change in the shikimic acid levels, phenylalanine, tyrosine, tryptophan, and shikimate- 3-phosphate, apart from causing intoxication in eucalyptus plants and reduction of dry mass. Glyphosate was detected in eucalyptus plants after application on the plants of B decumbens with low intoxicication ...

Orientador: Caio Antonio Carbonari
Banca: Edivaldo Domingues Velini
Banca: Leonardo David Tuffi Santos
Resumo: O eucalipto é a espécie florestal mais utilizada em reflorestamento no país, em virtude do rápido crescimento das plantas, condições climáticas e tecnologias desenvolvidas. Porém, a interferência das plantas daninhas causa grandes prejuízos, decréscimo quantitativo e qualitativo da produção do eucalipto. Entre as possibilidades de manejo de plantas daninhas, o método químico é o mais utilizado, porém, poucos são os herbicidas registrados para a cultura do eucalipto, entre os quais o glyphosate é o mais usado por controlar um grande número de espécies. Existem poucos trabalhos a respeito dos efeitos diretos e indiretos do glyphosate nesta espécie florestal. Neste trabalho, clones de eucalipto urograndis foram submetidos ao contato direto com o glyphosate e indireto por meio de aplicação sobre plantas de Brachiaria decumbens, visando caracterizar o movimento do herbicida, exsudação radicular e seus efeitos na planta. Foram realizadas avaliações de intoxicação visual do eucalipto aos 7, 14 e 21 DAA e da massa da matéria seca das plantas aos 21 DAA. Também foram realizadas quantificações por cromatografia líquida de alta eficiência e espectrometria de massas (LC-MS/MS) em diferentes partes das plantas (superior e inferior) dos seguintes compostos: glyphosate, ácido amimetilfofônico (AMPA), ácido chiquímico, chiquimato-3-fosfato, fenilalanina, tirosina e triptofano. O glyphosate foi detectado nas plantas de eucalipto para os tratamentos com a aplicação direta e indireta do herbicida e houve translocação para os locais que não foram atingidos na aplicação, mesmo quando aplicado sobre a B. decumbens, entretanto o AMPA não foi. A presença de glyphosate nas plantas influenciou na alteração dos níveis de ácido chiquímico, fenilalanina, tirosina, triptofano e chiquimato-3-fosfato, além de causar níveis de intoxicação nas plantas de eucalipto e redução de ...
Abstract: Eucalyptus is the most used forest species in reforestation in the country due to the rapid growth of plants, climatic conditions and developed technologies. However, interference by the weeds cause major damage, the quantitative and qualitative decrease in production of eucalyptus. Among the weed management possibilities, the chemical method is the most used, however, there are few herbicides registered for eucalyptus cultivation, in which glyphosate is most commonly used to control a large number of species. There are few studies regarding the direct and indirect effects of the glyphosate on this forest species. In this paper, Eucalyptus urograndis clones were subjected to direct contact with glyphosate and indirectly through application on Brachiaria decumbens plants, aiming to characterize the movement of the herbicide, root exudation and its effects on the plant. Visual evaluations were carried out through eucalyptus phytointoxication at 7, 14 and 21 DAA and of the dry mass of the plants at 21 DAA. Also, measurements were made on different parts of plants (top and bottom) of the following compounds by high-performance liquid chromatography and mass spectrometry (LC-MS / MS): glyphosate, aminomethylphosphonic acid (AMPA), shikimic acid, shikimate-3-phosphate, phenylalanine, tyrosine and tryptophan. Glyphosate was detected in eucalyptus plants for treatments with the direct and indirect application of herbicide and there was a translocation to sites that were not attain in the application, even when applied to the B. decumbens, however the AMPA was not. The presence of glyphosate on plants, influenced the change in the shikimic acid levels, phenylalanine, tyrosine, tryptophan, and shikimate- 3-phosphate, apart from causing intoxication in eucalyptus plants and reduction of dry mass. Glyphosate was detected in eucalyptus plants after application on the plants of B decumbens with low intoxicication ...
Mestre

Orientador: Marcelo de Almeida Silva
Banca: Carmen Silvia Fernandes Boaro
Banca: Edivaldo Domigues Velini
Banca: Elza Alves Correa
Banca: Eduardo Negrisoli
Resumo: Atualmente, tanto no setor de produção agrícola quanto nas diversas áreas da saúde humana, o efeito de subdoses de produtos aplicados, denominado como hormótico, vem sendo amplamente discutido e pesquisado, com o objetivo de compreender o mecanismo de ação estimulante e benéfica de diversas substâncias inicialmente consideradas como tóxicas, quando aplicadas em doses elevadas. O objetivo desta pesquisa foi verificar o efeito hormótico da subdose do herbicida glyphosate nas variáveis morfológicas, fisiológicas e a produção final de cana-de-açúcar. Os experimentos foram plantados em novembro de 2010 na Unidade de Pesquisa e Desenvolvimento de Jaú, SP, da APTA Pólo Centro-Oeste/SAA, conduzidos e avaliados durante o ciclo de cana-de-ano em cana-planta. A variedade utilizada foi a SP80-1842. Os tratamentos foram constituídos pela aplicação ou não de subdose de glyphosate. A aplicação dos tratamentos foi aos 70 dias após o plantio (DAP) e a subdose utilizada foi de 1,8 g e a ha-1 de glyphosate. No primeiro experimento foi avaliado o crescimento e desenvolvimento da cultura da cana-de-açúcar em parcelas de três linhas de plantio por três metros, nas quais foram coletadas um metro linear para avaliações em oito épocas, isto é, 70, 105, 140, 175, 210, 245, 280 e 315 dias após o plantio, em um delineamento de blocos casualizados com seis repetições. No segundo experimento, avaliou-se produtividade de colmos e de açúcar, foram utilizadas parcelas de cinco linhas de plantio por oito metros foram dispostas blocos casualizados com seis repetições, e coletadas ao final do ciclo da cultura, ou seja, aos 315 DAP. Em cada época de amostragem, do primeiro experimento, foram avaliados conteúdo de ácido chiquímico, ácido quínico, glyphosate e ácido aminometilfosfônico, teores de ...
Abstract: Currently, both in agricultural production and in areas of human health sector, the low dose effect of products applied, termed as hormetic, has been widely debated and researched in order to understand the mechanism of stimulating and beneficial action of several substances initially considered as toxic, when applied in high doses. The objective of this research was to investigate the effect of low dose of glyphosate on growth, phosphorus accumulation in the shoot, the production of shikimic and quinic acid, and final yield of sugarcane. The experiments were planted on November 05, 2010 in Research and Development Unit of Jaú, SP, APTA Polo Midwest / SAA, and carried out and evaluated over the course of the year in sugarcane plant cane. The variety used was SP80-1842. Two experiments were carried out to evaluate the effect hormetic during growth and development of sugarcane and cane yield and sugar. The treatments consisted at application or not of low dose of glyphosate. The spraying was at 70 DAP and the low dose dose used was 1.8 g a e ha-1 glyphosate. In the first experiment evaluated the growth and development of the sugar cane crop in portions of three planting rows of three meters, in which it was collected a linear meter for evaluations in eight times, or , 70, 105, 140, 175, 210, 245, 280 and 315 days after planting, in a randomized block design with six replications. In the second experiment, productivity was evaluated of stalks and sugar, plots were used in five plant lines by eight meters were willing randomized block design with six replications, and collected at the end of the cycle, or, to 315 DAP. At each sampling time, the first experiment examined content of shikimic acid, quinic acid ...
Doutor

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Este trabalho estima o impacto do glifosato sobre indicadores de saúde infantil no Brasil, no período de 2000 a 2009, explorando a adoção da soja transgênica no Brasil e a estrutura hidrográfica do país (ottobacias). Nossos resultados indicam um aumento nas taxas de nascimentos de baixo peso e mortalidade infantil, concentradas em causas de morte associadas aos efeitos esperados do glifosato e em crianças expostas ao glifosato durante o primeiro trimestre de gravidez (período em que o feto é mais suscetível a efeitos negativos sobre seu desenvolvimento). Assim, os resultados sugerem que a regulação do glifosato como herbicida pode ser melhorada levando-se em conta os efeitos negativos sobre a saúde humana, hoje negligenciados.
This work estimates the impact of glyphosate on infant health indicators in Brazil, between 2000 and 2009, exploiting the adoption of genetically engineered soy in Brazil and the country’s hidrographic structure (ottobasins). Our results indicate an increase in low weight birth rate and infant mortality rate, concentrated on death causes associated to glyphosate’s expected effects and on children exposed to glyphosate during the first trimester of pregnancy (when the fetus is more susceptible to negative developmental effects). Hence, the results suggest that regulation regarding use of glyphosate as herbicide can be improved taking into account the nowadays neglected negative effects on human health.

Boston University. University Professors Program Senior theses.
PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
2031-01-02

Thesis (Ph.D.)--University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 27, 2007) Vita. Includes bibliographical references.

Thesis (MScAgric)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: Glyphosate remains an important herbicide in weed control. This is due to several positive attributes it has including sytemicity, wide spectrum of weed control and environmental friendliness. Its efficacy and lack of residual activity are therefore important to ensure adequate weed control without imposing hazards to the environment. Despite these favourable attributes for weed control glyphosate has its shortcomings. Evolution of resistance to glyphosate has been a major concern from 1996. However, there are other factors that reduce the maximum potential of glyphosate. Any factors that reduce glyphosate efficacy may result in the target plant being subjected to non-lethal concentrations of glyphosate. This in turn may predispose the plants to developing herbicide resistance. Some factors that may influence efficacy of glyphosate, and therefore be possibly selecting for resistance were investigated in this study. Although glyphosate is a postemergence herbicide, its efficacy is not exempt from the effect of soil and nutrients in which the weeds occur. The possibility of this occurring was investigated in a greenhouse study on ryegrass (Lolium spp.) In this study ryegrass was grown in three soils: pure sand (SS), soil from pasture paddock (PS) and soil from crop field (CS). The soils varied in nutrient composition and, although all were classified as sand, they had varying proportions of sand, loam and clay. This investigation consisted of four experiments. The first experiment was investigating the effect of growing a susceptible commercial ryegrass cultivar on PS, CS and SS soils on the efficacy of glyphosate (360 g a.i. L-1 formulation) applied at five glyphosate application rates (GAR). The GARs were 0 (0x), 67.5 (1/8x), 135 (1/4x), 270 (1/2x) and 540 (1x) g a.i. ha-1. The second experiment investigated the effect of growing a susceptible commercial ryegrass cultivar and a glyphosate resistant ryegrass biotype on PS and CS soils on the efficacy of glyphosate. The application rates were 0 (0x), 270 (1/2x), 540 (1x), 1080 (2x) and 2160 (4x) g a.i. ha-1. The third and the fourth experiments were similar to the first experiment except: The latter investigated the role of nutrient content of irrigation water (pure water or balanced nutrient solution) and; the former investigated the effect of soil activity (by covering the soil surface with cotton at the time of spraying) of glyphosate with regard to the role it plays on efficacy of glyphosate. Our findings showed that: i) soil affects the efficacy of glyphosate with more control (19% survivors) found in the PS soil compared to 50% and 62% survivors in CS and SS soils respectively, this effect may be dependent upon the species resistance as; ii) the effect in the resistant ryegrass biotype was reversed with about 95% of survivors in the PS soil compared to about 78% in CS soil; iii) efficacy of glyphosate is influenced by the soil nutrient status and the nutrient content of the irrigation water. This was shown by decrease in the control of ryegrass (100% survivors) grown in SS soil when fed with pure water compared to 45% when nutrient fed. In PS soil there was no significant effect. This was probably due to inherently higher nutrient content of the PS soil; and iv) glyphosate efficacy is influenced by the amount of glyphosate reaching the soil (absorbed through the roots). This was shown in PS soil where 1/8x GAR resulted in 93.3% survivors in covered soil compared to 60% in uncovered soil. A similar trend was also observed at 1/4x GAR. An opposite effect was shown in SS soil with 0% and 40% survival at 1/4x GAR in the covered and uncovered soil respectively. Glyphosate has been hailed as an environmentally friendly herbicide as it rapidly degrades in soil and it sorbs on metals embedded in soil matrix. However, reports in the literature have showed reduction in crop yield due to soil glyphosate residues. In these studies, glyphosate phytotoxicity was found to be dependent on certain soil characteristics and nutrient content. Following this, a greenhouse study was conducted to assess the phytotoxic activity of glyphosate on a susceptible commercial ryegrass cultivar grown in PS, CS and SS soils. Glyphosate was applied at 0 (G1), 540 (G2) and 3240 (G3) g a.i. ha-1. Ryegrass seedlings of comparable size were transplanted into the soil at intervals of two hours, three weeks and four weeks after glyphosate application referred to as TAS1, TAS2 and TAS3 respectively. Evidence of soil glyphosate activity was shown by the decrease in percentage survival with the application of glyphosate. This was significant in the SS soil where about 60% and 48% survival in G1 and G2 GAR respectively was observed compared to about 100% in the untreated control when transplanted three weeks after glyphosate application. The decrease in percentage survival was time mediated with significant effect of G2 GAR shown at TAS 1 whereas at G3 GAR the effect was significant at TAS1 and TAS 2. At TAS 3 there was no effect at all GARs. Similar trends were observed with dry mass and shoot length. Trace metals required for normal plant growth have been implicated in the reduction of glyphosate efficacy. This follows glyphosate’s original development as a metal chelator. Glyphosate-trace metal antagonism has recently sparked interest following co-application in glyphosate resistant soybeans. Molybdenum (Mo), an anion, may play a role at the physiological level on the antagonism of glyphosate. A greenhouse assay was carried out where seedlings grown from seeds (of susceptible commercial ryegrass cultivar (S biotype) and glyphosate resistant biotype (R biotype)) were grown with nutrient solutions containing 0x, 1x and 2x molybdenum (Mo) concentrations where 1x is 0.05 mg L-1 Mo. Glyphosate was applied at 0 (0x), 135 (1/4x), 270 (1/2x), 540 (1x) and 1040 (2x) g a.i. ha-1 rates. In the R biotype applying 2x Mo resulted in 0% survival in the R biotype at 1x GAR compared to 50% and 90% survival at the same GAR with 0x and 1x Mo. In terms of dry mass and shoot length the results did not show any conclusive trends.
AFRIKAANSE OPSOMMING: Glifosaat is ‘n baie belangrike onkruiddoder wat in verskeie onkruidbeheerstelsels gebruik word. Dit is as gevolg van verskeie positiewe eienskappe waaroor dit besit onder andere sistemiese werking, wye spektrum van onkruidbeheer en omgewingsvriendelike werking. Die onkruiddoder se effektiwiteit en gebrek aan residuele aktiwiteit is dus belangrik om bevredigende onkruidbeheer te bewerkstellig sonder om skade aan die omgewing te veroorsaak. Ten spyte van hierdie voordelige eienskappe het glifosaat ook tekortkominge. Vanaf 1996 is ontwikkeling van weerstand teen glifosaat in onkruide ‘n groot bron van kommer. Daar is egter ook ander faktore wat die maksimum potensiaal van glifosaat strem. Enige faktore wat die effektiwiteit van glifosaat strem mag veroorsaak dat die teikenplant aan subletale dosisse van glifosaat blootgestel word. Dit mag weer daartoe lei dat sulke plante blootgestel word aan die ontwikkeling van weerstand. Sommige faktore wat die effektiwiteit van glifosaat mag strem en dus moontlik kan lei tot seleksie vir weerstand is in hierdie studie ondersoek. Alhoewel glifosaat ‘n na-opkoms middel is kan die effektiwiteit moontlik beïnvloed word deur grondfaktore en nutriënte. Hierdie moontlikheid is ondersoek in ‘n glashuisstudie waarin raaigras (Lolium spp.) gebruik is. In hierdie studie is raaigras geplant in drie verskillende grondsoorte nl. suiwer sand (SS), grond vanaf ‘n weidingskamp (PS) en grond vanaf ‘n gewasland (CS). Die gronde het gevarieer in terme van nutriëntinhoud en alhoewel al drie gronde as sand geklassifiseer is, was daar tog verskille in fisiese eienskappe. Hierdie afdeling het uit vier eksperimente bestaan. In die eerste eksperiment is die invloed van verskillende gronde (PS, CS en SS) waarin die kommersiële raaigras kultivar geplant was op die effektiwiteit van glifosaat (360 g a.b. L-1 formulasie) teen vyf verskillende dosisse (GAR) ondersoek. Die dosisse was 0 (0x), 67.5 (1/8x), 135 (1/4x), 270 (1/2x) and 540 (1x) g a.b. ha-1. Die tweede eksperiment het die invloed van twee grondsoorte (PS en CS) waarin ‘n vatbare kommersiële raaigras kultivar en ‘n glifosaat weerstandbiedende raaigras biotipe geplant is, se invloed op die effektiwiteit van glifosaat ondersoek. Die dosisse was 0 (0x), 270 (1/2x), 540 (1x), 1080 (2x) and 2160 (4x) g a.b. ha-1. Die derde en vierde eksperimente was soortgelyk aan die eerste eksperiment behalwe dat die derde eksperiment die invloed van voeding (suiwer gedistileerde water teenoor ‘n gebalanseerde voedingsoplossing) saam met besproeiing ondersoek het. In die vierde eksperiment is die grondwerking van glifosaat wat as blaarbespuiting toegedien is ondersoek deurdat sommige potte wat gespuit is se oppervlakte met ‘n laag watte bedek is tydens die spuitproses en dadelik na spuit verwyder is teenoor die ander behandeling waar die grondoppervlakte nie bedek is nie. Die resultate het getoon dat i) grondtipe die effektiwiteit van glifosaat beïnvloed met beter beheer (19% oorlewing) in die PS grond vergeleke met 50% en 62% oorlewing in die CS en SS grondtipes respektiewelik. Hierdie effek kan moontlik beïnvloed word deur die weerstandsvlak van spesies omdat ii) die effek in die weerstandbiedende biotipe omgekeer is met ongeveer 95% oorlewing in the PS grondtipe vergeleke met 78% in die CS grondtipe; iii) effektiwiteit van glifosaat is beïnvloed deur die voedingstatus van die grond en die besproeiingswater. Dit word aangedui deur die afname in beheer van raaigras (100% oorlewing) wat in SS grond gegroei het en met suiwer gedistilleerde water besproei is vergeleke met 45% oorlewing in dieselfde grond wanneer met ‘n gebalanseerde voedingsoplossing besproei is. Plante wat in PS grond gegroei het het geen betekenisvolle verskille tussen die besproeiingsbehandelings getoon in hulle reaksie op glifosaattoediening nie, waarskynlik as gevolg van die inherente hoër nutriëntinhoud van die grond en iv) glifosaat effektiwiteit word beïnvloed deur die hoeveelheid glifosaat wat die grond bereik en deur die wortels opgeneem word. Dit is bewys in plante wat in PS grond gegroei het waar 93.3% plante oorleef het waar die grondoppervlakte bedek was teenoor 60% oorlewendes waar die grondoppervlakte nie bedek was nie indien glifosaat teen 1/8x toegedien is. ‘n Soortgelyke tendens is by die 1/4x dosis waargeneem. ‘n Teenoorgestelde effek is in SS grond waargeneem waar die oorlewingspersentasie in bedekte en onbedekte grond by 1/4x glifosaatdosis 0% en 40% onderskeidelik was. Glifosaat is aanvanklik aangeprys as ‘n omgewingsvriendelike onkruiddoder omdat dit vinnig in grond afgebreek word en omdat dit geadsorbeer word aan metale in die grondmatriks. In teenstelling hiermee is daar egter verslae in die literatuur wat dui daarop dat glifosaatresidue in die grond gewasopbrengste kan verlaag. In die gemelde studies is gevind dat fitotoksisiteit van glifosaat residue afhang van grondeienskappe en grondvrugbaarheid. Na aanleiding hiervan is ‘n glashuisstudie uitgevoer waarin die fitotoksisiteit van residuele glifosaat op ‘n kommersiële raaigraskultivar wat in PS, CS en SS gronde groei, ondersoek is. Glifosaat is op die grond in potte toegedien teen 0 (G1), 540 (G2) and 3240 (G3) g a.b. ha-1. Raaigras saailinge is daarna in die potte ingeplant twee ure, drie weke en vier weke nadat die glifosaat toegedien is. Bewys van grondaktiwiteit van glifosaat is gelewer deur die vermindering in persentasie oorlewing van die saailinge met toediening van glifosaat. Die vermindering in oorlewing was betekenisvol in die SS grond waar ongeveer 60% en 48% oorlewing van saailinge was by G2 en G3 dosisse onderskeidelik teenoor 100% oorlewing in die onbehandelde kontrole. Die afname in persentasie oorlewing is deur tyd beïnvloed deurdat die G2 dosis slegs by die twee ure behandeling betekenisvolle verlaging in oorlewing veroorsaak het terwyl die G3 dosis by die twee ure sowel as die drie weke behandeling betekenisvolle verlagings veroorsaak het. Vier weke na toediening was daar geen effek van glifosaat op die saailinge in enige van die gronde gewees nie. Soortgelyke tendense is waargeneem by die droëmassa en lengte data. Spoorelemente wat noodsaaklik is vir normale plantgroeiprosesse is al geïmpliseer in verlaging van glifosaat effektiwiteit. Dit is waarskynlik omdat glifosaat oorspronklik ontwikkel is as ‘n metaal cheleerder. Glifosaat-spoorelement antagonisme was onlangs in die nuus nadat glifosaat saam met sulke elemente toegedien is op glifosaat weerstandbiedende sojabone. Molibdeen (Mo), ’n anioon, mag ’n rol op fisiologiese vlak speel in doie effektiwiteit van glifosaat. ‘n Glashuisstudie is uitgevoer waarin saailinge van ‘n glifosaat vatbare kommersiële raaigras kultivar en ‘n glifosaat weerstandbiedende raaigras biotipe besproei is met voedingsmengsels wat 0x, 1x en 2x Mo bevat waar 1x 0.05 mg L-1 Mo is. Glifosaat is op die plante toegedien teen 0 (0x), 135 (1/4x), 270 (1/2x), 540 (1x) and 1040 (2x) g a.b. ha-1 dosisse. Die 2x Mo toediening het gelei tot 0% oorlewing in die R biotipe by 1x GAR vergeleke met 50% en 90% oorlewing by dieselfde GAR met 0x en 1x Mo. In terme van droëmateriaal en lengtegroei was daar geen konkrete tendense nie.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A cultura do eucalipto apresenta uma grande importância no cenário econômico nacional e mundial, oferecendo uma vasta gama de produtos florestais. No entanto, a disponibilidade de fósforo nos solos raramente é adequada para o crescimento, desenvolvimento e produtividade das plantas de eucalipto, bem como para diversas outras culturas. A presença de plantas daninhas em eucaliptais é outro fator limitante, e para o manejo da comunidade infestante, glyphosate é o herbicida mais utilizado. As plantas de eucalipto, quando cultivadas em diferentes concentrações de fósforo, podem alterar a expressão gênica de transportadores de fosfato. Em algumas condições, a síntese de transportadores de fosfato de alta afinidade pode ser incrementada. Esses transportadores podem ter afinidade pelo grupo fosfonato do glyphosate, transportando esse herbicida via membrana plasmática. Assim, podem ocorrer alterações no comportamento do glyphosate em função das concentrações de fósforo. Estudos do efeito diferencial de glyphosate em função de concentrações de fósforo e do transporte de glyphosate mediado por transportadores de fosfato ainda são escassos, principalmente em uma espécie perene, como o eucalipto. Com essa pesquisa objetivou-se (1) avaliar, em clones de Eucalyptus urophylla (GG100 e I144) a cinética de absorção de fósforo, as eficiências nutricionais de macronutrientes e seus reflexos no crescimento das plantas; (2) verificar as alterações fotossintéticas, metabólicas e nutricionais de clones de E. urophylla (GG100 e I144) cultivados em concentrações de fósforo e submetidos à aplicação de glyphosate; e (3) estudar, em E. grandis, a coordenação da expressão gênica de transportadores de fosfato, a absorção e a translocação de 14C-glyphosate, e o transporte de 14C-glyphosate através da membrana plasmática em protoplastos. Os experimentos com E. urophylla foram realizados na Universidade Estadual Paulista, Câmpus de Jaboticabal, SP, enquanto aqueles com E. grandis foram desenvolvidos na University of Maryland, Maryland, EUA. Após a avaliação dos parâmetros cinéticos de absorção de fósforo, o clone I144 foi superior, apresentando menores Cmín e Km (concentração limite abaixo da qual a planta é incapaz de absorver um elemento na solução e concentração do nutriente na solução onde foi atingida metade da Vmáx, respectivamente) e maior Vmáx (velocidade máxima de absorção). As eficiências de absorção, translocação e utilização de macronutrientes também foram maiores no clone I144, com exceção da eficiência de utilização de potássio, superior no clone GG100. Não houve diferenças na eficiência nutricional dos clones em relação ao boro. Para a avaliação das alterações fotossintéticas, metabólicas e nutricionais ocasionadas por glyphosate em função de concentrações de fósforo, experimentos foram conduzidos em casa de vegetação utilizando areia como substrato (pulverização foliar de glyphosate) e em câmara de crescimento utilizando sistema hidropônico (aplicação radicular de glyphosate). Para ambos os experimentos, os nutrientes foram oferecidos por meio da solução nutritiva, que foi ajustada para as doses de fósforo 0,5X; 1X e 1,5X de fósforo (em que X correspondeu à concentração de fósforo recomendada para o preparo da solução nutritiva). Interações entre as concentrações de fósforo e as doses de glyphosate ocorreram nas características que avaliaram o processo fotossintético (teores de clorofila e eficiência quântica do fotossistema II), nos teores de glyphosate, AMPA e ácido chiquímico, nos teores nutricionais e massas secas. Essas características ou teores foram menores ou mais intensamente reduzidos, após glyphosate, nas plantas cultivadas com menores concentrações de fósforo (0,5X e, em alguns casos, 1X). Por fim, experimentos foram conduzidos em E. grandis, e a expressão gênica dos transportadores de fosfato (mensurada por meio de RT-qPCR) nas folhas e nas raízes dessas plantas foram alteradas em resposta a deficiência de fosfato. A expressão de transportadores de alta afinidade foi incrementada pela deficiência de fosfato. A absorção de 14C-glyphosate aplicado via foliar ou radicular foi maior nas plantas submetidas à deficiência de fosfato, e a translocação deste herbicida também foi mais rápida nessas plantas. Nos protoplastos, o transporte de 14C-glyphosate via membrana plasmática ocorreu rapidamente na ausência de fosfato, e de modo mais lento quando NaH2PO4 foi adicionado ao meio. Possivelmente, o transporte de fosfato através da membrana plasmática foi realizado em um primeiro momento, e com a redução do fosfato disponível no meio, o transporte de glyphosate foi iniciado, provavelmente, por transportadores de fosfato de alta afinidade.
Eucalypt plantation have great importance in the national and global economic environment, offering a wide range of forest products. However, the phosphorus availability in soils is rarely appropriate for growth, development and yield of eucalypt plants, as well as several other crops. The presence of weeds in eucalypt plantations is another limiting factor, and for weed management glyphosate is the most used herbicide. Eucalypt plants grown under different phosphorus concentrations can change phosphate transporters gene expression. Under specific conditions, high-affinity phosphate transporter synthesis can be increased. Such transporters can have affinity for glyphosate phosphonate group, transporting this herbicide through plasma membrane. So, changes may occur in glyphosate behavior depending on phosphorus concentrations. Studies of glyphosate effect as a function of phosphorus concentrations and glyphosate transport mediated by phosphate transporters are still scarce, especially in a perennial species, such as eucalypt. This study aimed (1) to evaluate, in Eucalyptus urophylla clones (GG100 and I144), the phosphorus absorption kinetics, the nutritional efficiency of macronutrients and their effects on plant growth; (2) verify the photosynthetic, nutritional and metabolic changes in E. urophylla clones (GG100 and I144) grown under phosphorus concentrations and submitted to glyphosate application; and (3) study in E. grandis the phosphate transporters gene expression coordination, the 14C-glyphosate uptake and translocation, and the 14C-glyphosate transport through the plasma membrane in protoplasts. The experiments with E. urophylla were carried out at São Paulo State University, Campus of Jaboticabal, SP, while the experiment with E. grandis were developed at University of Maryland, Maryland, USA. After the evaluation of phosphorus absorption kinetic parameters, I144 clone was considered superior, presenting lower Cmin and Km (respectively, the limiting concentration for absorbing an element in solution and the nutrient concentration in solution which was reached half of Vmax,) and higher Vmax (maximum rate of absorption). The efficiency of absorption, translocation and utilization of macronutrients were also higher in I144 clone, with the exception of potassium utilization efficiency, higher in GG100 clone. No differences in boron nutritional efficiency were found. For the evaluation of photosynthetic, nutritional and metabolic changes caused by glyphosate according phosphorus concentrations, experiments were performed in a greenhouse using sand (glyphosate sprayed in leaves) and in a growth chamber using hydroponic system (glyphosate applied in roots). For both experiments, nutrients were provided by nutrient solution, which was adjusted to phosphorus levels 0.5X, 1X and 1.5X (where X corresponded to the phosphorus concentration recommended for nutrient solution preparation). Interactions between phosphorus concentration and glyphosate doses occurred in the characteristics that evaluated the photosynthetic process (chlorophyll content and quantum efficiency of photosystem II), in the glyphosate, AMPA and shikimic acid content, and in the nutritional content and dry mass. These characteristics or contents were smaller or more strongly reduced after glyphosate in plants grown with lower phosphorus concentration (0.5X, and in some cases, 1X). Finally, experiments were conducted in E. grandis, and the gene expression of phosphate transporters (measured by RT-qPCR) in leaves and roots of these plants have been modified as a phosphate deficiency response. High-affinity transporters expression was increased by phosphate deficiency. The absorption of 14C-glyphosate applied in leaves or roots was higher in plants subjected to phosphate deficiency, and glyphosate translocation was also faster in these plants. In protoplasts, 14Cglyphosate transport via plasma membrane was fast in phosphate absence and slower when NaH2PO4 was added to the medium. Possibly, the phosphate transport through the plasma membrane was performed initially, and with the phosphate reduction in the medium, the glyphosate transport was started probably for highaffinity phosphate transporters.
CNPq: 156323/2012-5
CAPES: BEX-9553/14-2
FAPESP: 2011/201705-3

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O efeito de estímulo de uma característica biológica por baixas doses de um composto considerado tóxico, mas que em altas doses tem efeito inibitório é denominado efeito hormesis. Estímulos de crescimento em plantas têm sido verificados após a aplicação de subdoses de alguns herbicidas, incluindo o glyphosate. Nesse contexto, o presente trabalho teve por objetivo avaliar as respostas de crescimento de plantas de Brachiaria decumbens submetidas a diferentes doses de glyphosate. Foram realizados dois estudos em casa de vegetação, ambos em delineamento inteiramente casualizado (DIC). No primeiro estudo foram realizados três experimentos com seis repetições, sendo no experimento 1 testada uma curva de dose-resposta com nove doses do herbicida glyphosate (0; 22,5; 45; 90; 180; 360; 720; 1440 e 2880 g e.a. ha-1). Nos experimentos dois e três foram aplicadas onze doses do herbicida glyphosate (0; 2,8125; 5,625; 11,25; 22,5; 45; 90; 180; 360; 720 e 1440 g e.a. ha-1). No estudo 2 para a avaliação de subdoses com efeito hormesis realizou-se quatro experimentos, em DIC com oito repetições e dois tratamentos (testemunha e dose de 11,25 g e.a. ha-1). Para ambos os estudos foram coletadas oito plantas de vasos sem aplicação para a determinação da biomassa inicial dos experimentos. Nos experimentos do estudo 1 foram realizadas avaliações de fitointoxicação aos 0, 7, 14 e 21 dias após a aplicação (DAA), além da coleta de oito plantas por vaso de cada tratamento para determinação de massa fresca e massa seca. Além disso, realizou-se a quantificação de massa fresca e seca total dos vasos aos 21 DAA, sendo essa metodologia também adotada para os experimentos do estudo 2. Os resultados do estudo 1 indicaram que: em doses acima de 45 g e.a. ha-1 foi possível obter 80% de controle das plantas de B. decumbens; a aplicação de baixas doses de glyphosate estimulou o aumento da biomassa das plantas de B. decumbens, com valores máximos alcançados na subdose de 11,25 g e.a. ha-1 de glyphosate. O segundo estudo indicou que a aplicação de subdose de 11,25 g e.a. ha-1 de glyphosate promoveu tanto estímulo quanto inibição de crescimento, demonstrando haver variabilidade de resposta das plantas à essa subdose.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Panicum maximun está entre as plantas daninhas mais importantes nas culturas tropicais, justificando plenamente a necessidade de controlá-la, o que é feito basicamente com o emprego de herbicidas. Diante disso, objetivou-se avaliar o efeito de subdoses de glyphosate nas trocas gasosas, crescimento e morfologia de P. maximun. O experimento foi realizado em casa-de-vegetação, sendo as plantas cultivadas em vasos, em delineamento inteiramente casualizado, com quatro repetições. Os tratamentos experimentais foram constituídos por uma testemunha (sem aplicação do produto) e nove doses (3,78; 8,10; 16,64; 33,48; 67,70; 135,00; 270,00; 540,00 e 1080,00 g e.a. ha-1). Foram avaliados os parâmetros fisiológicos: fotossíntese líquida, condutância estomática, transpiração, temperatura foliar, concentração interna de CO2. Também foram avaliados o número de perfilhos e intoxicação das plantas e, ao final do experimento determinou-se o acúmulo de massa seca da parte aérea e área foliar. Os dados obtidos foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de probabilidade. Quando significativos, realizou-se análise de regressão usando os modelos para as curvas de dose-resposta. Os parâmetros fisiológicos avaliados, foram influenciados positivamente pelas subdoses de glyphosate, apresentando maiores valores que a testemunha. A concentração interna de CO2 foi negativamente afetada, mas houve incremento na temperatura da folha de forma progressiva. Além disso, promoveram aumento na massa seca da parte aérea e da área foliar. Diante disso, concluiu-se que houve efeito hormético nas plantas de Panicum maximun, quando submetidas as doses de 3,78 a 270 g e.a ha-1 de glyphosate.
Panicum maximum is among most important weed specie in tropical crops, justifying the need to control it, basically with herbicides. Therefore this work aimed to evaluate glyphosate sub dose in the gas exchange, dry mass and morphological in P.maximum. The experiment was conducted in a green house, plants were grown in plots, with a casually randomized design, with four replications. The experimental treatments were constituted with one control ( without application of the product) and nine doses of glyphoste(3.78: 8.1: 16.64: 33.48: 67.7: 135: 270: 540: 1080 g a.e. ha-1 ). It was evaluated: Liquid photosintesys, estomatic conductance, transpiration, leaf temperature, intern CO2 concentration. Besides it was evaluated tillering and intoxication, at the end of the experiment it was determined the aerial dry mass and leaf area. The data obtained was submitted to a variance analysis test and means submitted to a Tukey test at 5 % probability and when significative was used regression using the models for dose response curves. The physiological parameters evaluated where positive influenciated by the glyphosate sub dose showing higher values than the control, furthermore the intern CO2 concentration was negative influenced, beyond it was observed increment in the leaf temperature progressively, also promote an increment for aerial dry mass accumulation and leaf area besides. Further more, concluding that in the Panicum maximun plants submitted to the glyphosate doses of 3,78 to 270 g a.e. ha-1 showed and hormetic effect.
CNPq: 133038/2015-7

Orientador: Edivaldo Domingues Velini
Banca: Caio Atonio Carbonari
Banca: Luciano Soares de Souza
Resumo: O efeito de estímulo de uma característica biológica por baixas dosesde um composto considerado tóxico, mas que em altas doses tem efeito inibitório édenominado efeito hormesis. Estímulos de crescimento em plantas têm sido verificados apósa aplicação de subdoses de alguns herbicidas, incluindo o glyphosate. Nesse contexto, opresente trabalho teve por objetivo avaliar as respostas de crescimento de plantas deBrachiaria decumbens submetidas a diferentes doses de glyphosate. Foram realizados doisestudos em casa de vegetação, ambos em delineamento inteiramente casualizado (DIC). Noprimeiro estudo foram realizados três experimentos com seis repetições, sendo noexperimento 1 testada uma curva de dose-resposta com nove doses do herbicida glyphosate(0; 22,5; 45; 90; 180; 360; 720; 1440 e 2880 g e.a. ha-1). Nos experimentos dois e três foramaplicadas onze doses do herbicida glyphosate (0; 2,8125; 5,625; 11,25; 22,5; 45; 90; 180;360; 720 e 1440 g e.a. ha-1). No estudo 2 para a avaliação de subdoses com efeito hormesisrealizou-se quatro experimentos, em DIC com oito repetições e dois tratamentos (testemunhae dose de 11,25 g e.a. ha-1). Para ambos os estudos foram coletadas oito plantas de vasos semaplicação para a determinação da biomassa inicial dos experimentos. Nos experimentos doestudo 1 foram realizadas avaliações de fitointoxicação aos 0, 7, 14 e 21 dias após a aplicação(DAA), além da coleta de oito plantas por vaso de cada tratamento para determina... (Resumo completo, clicar acesso eletrônico abaixo)
Mestre

Orientador: Pedro Luis da Costa Aguiar Alves
Coorientador: Silvano Bianco
Coorientador: Wendy Ann Peer
Banca: Edivaldo Domingues Velini
Banca: Rinaldo Cesar de Paula
Banca: Priscila Lupino Gratão
Banca: Tiago Pereira Salgado
Resumo: A cultura do eucalipto apresenta uma grande importância no cenário econômico nacional e mundial, oferecendo uma vasta gama de produtos florestais. No entanto, a disponibilidade de fósforo nos solos raramente é adequada para o crescimento, desenvolvimento e produtividade das plantas de eucalipto, bem como para diversas outras culturas. A presença de plantas daninhas em eucaliptais é outro fator limitante, e para o manejo da comunidade infestante, glyphosate é o herbicida mais utilizado. As plantas de eucalipto, quando cultivadas em diferentes concentrações de fósforo, podem alterar a expressão gênica de transportadores de fosfato. Em algumas condições, a síntese de transportadores de fosfato de alta afinidade pode ser incrementada. Esses transportadores podem ter afinidade pelo grupo fosfonato do glyphosate, transportando esse herbicida via membrana plasmática. Assim, podem ocorrer alterações no comportamento do glyphosate em função das concentrações de fósforo. Estudos do efeito diferencial de glyphosate em função de concentrações de fósforo e do transporte de glyphosate mediado por transportadores de fosfato ainda são escassos, principalmente em uma espécie perene, como o eucalipto. Com essa pesquisa objetivou-se (1) avaliar, em clones de Eucalyptus urophylla (GG100 e I144) a cinética de absorção de fósforo, as eficiências nutricionais de macronutrientes e seus reflexos no crescimento das plantas; (2) verificar as alterações fotossintéticas, metabólicas e nutricionais de clo... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Eucalypt plantation have great importance in the national and global economic environment, offering a wide range of forest products. However, the phosphorus availability in soils is rarely appropriate for growth, development and yield of eucalypt plants, as well as several other crops. The presence of weeds in eucalypt plantations is another limiting factor, and for weed management glyphosate is the most used herbicide. Eucalypt plants grown under different phosphorus concentrations can change phosphate transporters gene expression. Under specific conditions, high-affinity phosphate transporter synthesis can be increased. Such transporters can have affinity for glyphosate phosphonate group, transporting this herbicide through plasma membrane. So, changes may occur in glyphosate behavior depending on phosphorus concentrations. Studies of glyphosate effect as a function of phosphorus concentrations and glyphosate transport mediated by phosphate transporters are still scarce, especially in a perennial species, such as eucalypt. This study aimed (1) to evaluate, in Eucalyptus urophylla clones (GG100 and I144), the phosphorus absorption kinetics, the nutritional efficiency of macronutrients and their effects on plant growth; (2) verify the photosynthetic, nutritional and metabolic changes in E. urophylla clones (GG100 and I144) grown under phosphorus concentrations and submitted to glyphosate application; and (3) study in E. grandis the phosphate transporters gene expression coord... (Complete abstract click electronic access below)
Doutor

Type one diabetes (T1D) and islet autoimmunity (IA) in people with a genetically susceptibility for the diseases can be triggered by environmental factors. It is earlier showed that the diet can be one of the environmental factors as it has been indicated that a cereal rich diet can increase the risk of developing IA. In this study, we investigated blood plasma samples from a study done by L. Hakolas on children that have genetic risk of developing T1D and IA, with a focus on dietary contaminants originating from cereals. Mycotoxins often found on cereals could be one of the environmental factors triggering the development of the diseases. To see if this could be the case a method based on a liquid chromatography coupled with a quadrupole-time of flight (LC-QTOF) was developed for the analysis of mycotoxins and glyphosate; MS/MS mode was used after that to confirm the identity of the compounds. For sample preparation, protein precipitation of the plasma samples was applied. The method was optimized by analyzing 5 mycotoxin standards and a list of suspected compounds that could be found in the screening to make sure the method could separate all the compounds. Test plasma samples was also analyzed to determine the optimal plasma volume (100 mL) for extraction and injection volume (15mL). For the data preprocessing, MZmine software was used and could tentatively identify some of the mycotoxins based on accurate mass acquisition. After comparing the signal against the background noise, Ergotaminine, FB1, Gly and HT-2 and NIV were identified. As quality control three replicates of a pooled sample were analysed, using both positive and negative ionization modes. From the pooled sample mean, standard deviation (STD) and relative standard deviation (RSD) were calculated showing some variation among the plasma sample for some mycotoxins e.g., Gly. The results presented in this report show that some mycotoxins do occur in the blood plasma and that the amounts of the mycotoxins varied. However, how these mycotoxins can affect the progress of T1D and IA is still unknown and requires further studies.

Thesis (M.S.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 10, 2009) Includes bibliographical references.

Field and greenhouse experiments were conducted in 2008, 2009, and 2010 to evaluate the efficacy of glyphosate combined with other broadleaf herbicides on herbicide-resistant and -susceptible weeds in Illinois. In the field, the addition of lactofen or fomesafen to glyphosate provided the greatest consistency and control of problematic target weeds including common waterhemp and giant ragweed. Applications of glyphosate tank-mixtures at EPOST provided 10% greater control of giant ragweed compared with the same treatments at POST. The addition of a tank-mix herbicide with glyphosate provided the greatest impact on weed control when applied to glyphosate-resistant common waterhemp with control increasing by 67% compared with glyphosate applied alone. The addition of a tank-mix herbicide with glyphosate had little impact on control of PPO-resistant and herbicide-susceptible common waterhemp. Generally, the addition of an adjuvant to herbicide mixtures with glyphosate did not influence weed control 14 DAT compared with no additional adjuvant. However, the addition of PO-HSOC and SO-HSOC to glyphosate tank-mixtures containing fomesafen and cloransulam increased annual morningglory control compared with no additional adjuvant. In the greenhouse, PPO-inhibiting herbicides (fomesafen, lactofen, flumiclorac, fluthiacet) applied with glyphosate resulted in additive and antagonistic responses depending on the PPO-inhibitor used and the common waterhemp biotype. Generally, glyphosate tank-mixtures applied to PPO-resistant and herbicide-susceptible common waterhemp biotypes resulted in a greater frequency of antagonism than that of a glyphosate-resistant biotype. The efficacy of glyphosate tank-mixtures was also influenced by environmental conditions shortly before and after the herbicide application. Glyphosate tank-mixtures usually resulted in greater efficacy on common waterhemp when applied at 24 C with 75% RH than at 32 C with 40% RH, regardless of tank-mix herbicide or common waterhemp biotype. Although this research supports an improvement in control of glyphosate-resistant common waterhemp with the addition of PPO-inhibiting herbicides to glyphosate, the overall herbicide efficacy was still somewhat variable with evidence for environmental conditions that may alter efficacy of the tank mixtures. Thus, the use of preemergence, soil residual herbicides are still justified to reduce reliance on these postemergence herbicide mixtures for weed control in soybean and ultimately deter further selection of common waterhemp populations resistant to glyphosate and PPO-inhibiting herbicides.

Orientador: Pedro Luis da Costa Aguiar Alves
Coorientador: Alcebíades Rebouças São José
Banca: Silvano Bianco
banca: Tiago Pereira Salgado
Resumo: Panicum maximun está entre as plantas daninhas mais importantes nas culturas tropicais, justificando plenamente a necessidade de controlá-la, o que é feito basicamente com o emprego de herbicidas. Diante disso, objetivou-se avaliar o efeito de subdoses de glyphosate nas trocas gasosas, crescimento e morfologia de P. maximun. O experimento foi realizado em casa-de-vegetação, sendo as plantas cultivadas em vasos, em delineamento inteiramente casualizado, com quatro repetições. Os tratamentos experimentais foram constituídos por uma testemunha (sem aplicação do produto) e nove doses (3,78; 8,10; 16,64; 33,48; 67,70; 135,00; 270,00; 540,00 e 1080,00 g e.a. ha-1). Foram avaliados os parâmetros fisiológicos: fotossíntese líquida, condutância estomática, transpiração, temperatura foliar, concentração interna de CO2. Também foram avaliados o número de perfilhos e intoxicação das plantas e, ao final do experimento determinou-se o acúmulo de massa seca da parte aérea e área foliar. Os dados obtidos foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de probabilidade. Quando significativos, realizou-se análise de regressão usando os modelos para as curvas de dose-resposta. Os parâmetros fisiológicos avaliados, foram influenciados positivamente pelas subdoses de glyphosate, apresentando maiores valores que a testemunha. A concentração interna de CO2 foi negativamente afetada, mas houve incremento na temperatura da folha de forma progressiva. Além disso... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Panicum maximum is among most important weed specie in tropical crops, justifying the need to control it, basically with herbicides. Therefore this work aimed to evaluate glyphosate sub dose in the gas exchange, dry mass and morphological in P.maximum. The experiment was conducted in a green house, plants were grown in plots, with a casually randomized design, with four replications. The experimental treatments were constituted with one control ( without application of the product) and nine doses of glyphoste(3.78: 8.1: 16.64: 33.48: 67.7: 135: 270: 540: 1080 g a.e. ha-1 ). It was evaluated: Liquid photosintesys, estomatic conductance, transpiration, leaf temperature, intern CO2 concentration. Besides it was evaluated tillering and intoxication, at the end of the experiment it was determined the aerial dry mass and leaf area. The data obtained was submitted to a variance analysis test and means submitted to a Tukey test at 5 % probability and when significative was used regression using the models for dose response curves. The physiological parameters evaluated where positive influenciated by the glyphosate sub dose showing higher values than the control, furthermore the intern CO2 concentration was negative influenced, beyond it was observed increment in the leaf temperature progressively, also promote an increment for aerial dry mass accumulation and leaf area besides. Further more, concluding that in the Panicum maximun plants submitted to the glyphosate doses of 3,78 to 270 g a.e. ha-1 showed and hormetic effect.
Mestre

The wide use of glyphosate-based herbicides (GBHs) has become a controversial issue due to the potential harmful effects on human health. Commercial formulations, among which Roundup is the most famous one, contain a number of adjuvants inside; most of these are patented and not publicly known, therefore, they can act differently from glyphosate alone and might strengthen its toxic effect. Our study is focused on GBHs reproductive toxicity with a special regard to glyphosate and Roundup impact on male and female mammalian gametes after exposure to concentrations ranging from the one recommended for agricultural use (0.1% Roundup, containing 360 µg/mL glyphosate) to 70-fold lower or more. Sperm quality analysis, either on boar and stallion, showed that Roundup has much more detrimental impact than glyphosate at equivalent concentrations on spermatozoa function and survival. Basing on our results, the toxic effect of these pesticides on spermatozoa may be linked to an impairment in mitochondrial activity and a subsequent decrease in ATP production and/or alterations in the redox balance, which impact cell motility and plasma membrane stability. Moreover, a different species sensitivity to GBHs may exists as high doses of glyphosate affected sperm quality only in boar and not in stallion; furthermore, Roundup had deleterious effects at lower doses in the first compared to the latter. With regard to female gametes, we found that glyphosate and Roundup exposure during IVM detrimentally affect the subsequent developmental ability of swine embryos, providing further evidence of their potential toxic effect on female reproductive system. In addition, Roundup altered steroidogenesis and increased oocyte ROS levels. Therefore, according to our results, we can conclude that GBHs exert a negative impact on both male and female gametes and that Roundup adjuvants enhance glyphosate toxic effects and/or are biologically active in their side-effect.

Master of Science
Agronomy
Johanna A. Dille
Mithila Jugulam
Common lambsquarters (Chenopodium album L.) is an annual broadleaf weed species that competes with more than 40 crop species around the world. A biotype of common lambsquarters in north central KS (DK) was not controlled by a glyphosate application. Plant growth stage and temperature have been related to overall glyphosate efficacy on common lambsquarters. The objectives were to determine the: 1) tolerance of two biotypes of common lambsquarters to glyphosate, 2) efficacy of glyphosate on common lambsquarters at different growth stages, and 3) efficacy of glyphosate on common lambsquarters when grown at different temperatures. Greenhouse dose-response experiments, shikimate accumulation assay, and glyphosate uptake and translocation experiments were conducted using DK biotype and a known susceptible biotype (RL) of common lambsquarters for comparison. Dose-response results indicated elevated tolerance of the DK biotype to glyphosate based on the GR₅₀ (a dose causing 50% biomass reduction) values (373 g ae/ha for RL vs. 552 g ae/ha for DK). Similarly, the DK biotype accumulated slightly less shikimate in the leaf discs compared to the RL biotype. Minimal differences were observed in ¹⁴C-glyphosate uptake and translocation between the two biotypes. Greenhouse-grown common lambsquarters were treated with glyphosate at a field dose (1x) of 840 g ae/ha when they were 5-7, 10-12, 15-17 or 19-21 cm tall. Common lambsquarters were also grown in growth chambers for 1 wk maintained at d/n temperatures of 25/15, 32.5/22.5, or 40/30 C and then treated with 0-, 0.125-, 0.25-, 0.5-, 0.75, 1.0-, and 2.0-x rates of glyphosate at 8-10 cm tall. Visual injury was recorded 1 WAT and biomass was determined 2 WAT. Common lambsquarters plants treated at 5-7 cm were more susceptible than larger plants to glyphosate. Furthermore, plants were more susceptible to glyphosate when grown under lower temperatures of 25/15 C than higher temperatures. Overall, these results suggest that the DK biotype of common lambsquarters appears to have elevated tolerance to glyphosate. Additionally, glyphosate should be applied early in the season when plants are small and temperatures are cooler for optimal control of common lambsquarters.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
O fósforo é um elemento essencial para todos os organismos vivos como um componente estrutural dos ácidos nucléicos e fosfolipídios. Além disso, nas plantas o fósforo é de fundamental importância na fotossíntese. A mobilização do fosfato dentro da planta é um processo complexo que requer numerosos transportadores para a sua absorção e translocação. A deficiência de fósforo é um dos maiores estresses abióticos que afetam o crescimento das plantas, especialmente em solos tropicais. O Glyphosate (N-phosphonomethyl-glycine) é o único composto comercialmente disponível que atua na enzima EPSPS. Tal composto é um herbicida sistêmico, não-seletivo, de amplo uso, com translocação via simplasto. Denis e Delrot (1993) e Morin et al. (1997) demonstraram que proteínas transportadoras de grupos fosfatos, que estão presentes na membrana plasmática de Vicia faba e Catharanthus roseus, facilitaram a absorção de glyphosate. O objetivo deste trabalho foi avaliar o efeito de subdoses de glyphosate na absorção e translocação de fósforo nas cultivares de soja, BRS 232 e BRS 243 RR. O experimento foi conduzido em casa de vegetação, e as cultivares semeadas em vasos de 8 litros. Os tratamentos foram constituídos de adubação de plantio com duas doses de 2 fósforo (50 e 150 mg L-1) e dez doses de glyphosate (0, 1,8, 3,6, 7,2, 18, 36, 72, 180, 360 e 720 g i.a. ha-1). As plantas receberam a aplicação do herbicida quando apresentaram o terceiro trifólio expandido. Após a aplicação, estas foram conduzidas por trinta dias, e então colhidas e analisadas. As análises realizadas foram: matéria seca de folha, caule e raiz, teores de fósforo e conteúdo total de fósforo das mesmas. Para a soja convencional BRS 232 (não resistente ao glyphosate) houve estímulos ao crescimento das plantas para doses entre 3,6 e 36g e.a./ha. Para esta variedade...
Phosphorous is an essential element for all living organisms acting as a structural component of nucleic acids as well as phospholipids. Besides it is of fundamental importance in photosynthesis. The maintenance of phosphate within the plant is a complex process which requires numerous transporters for its absorption and translocation. Phosphorous deficiency is one of the major abiotic stresses affecting plant growth in tropical regions. Glyphosate (N-phosphonomethyl-glycine) is the only compound commercially available which acts upon EPSPS enzyme. It is a systemic, non-selective, broad-spectrum herbicide with translocation via symplast. Transporter proteins of phosphate groups which are present at plasma membrane facilitated glyphosate absorption. This paper aims at evaluating the effects of low doses of glyphosate in phosphorous absorption and translocation in soybean crops BRS 232 e BRS 243 RR. The experiment was carried out under greenhouse conditions and plants were cultivated in 8-liter pots. The treatments were disposed in a factorial scheme combining two doses of phosphorus (50 and 150 mg L-1) and ten doses of glyphosate (0; 1.8; 3.6; 7.2; 18; 36; 72; 180; 360 and 20 g i.a. ha-1). Glyphosate was applied to plants at the third expanded three-leaf. After thirty days plants were harvested and dry matter, stems, root, phosphorous levels and the total content of phosphorous were measured. Glyphosate aplied at rates ranging from 3,6 to 36 g a.e/ha stimulated the growth and phosphorus absorption by the conventional soybean variety BRS 232 (not resistant to glyphosate) and the stronger effects were observed for the lower level of phosphorus in the soil. In this condition, glyphosate applied at 18 g a.e./ha increased in 2,61 times the phosphorus concentration in leaves. Glyphosate didn t stimulate the growth 4 but increased the absorption of phosphorus... (Complete abstract click electronic access below)

Pre-harvest glyphosate is applied to cereal grains to remove weeds. However, it has been claimed that oat compositions are affected by pre-harvest glyphosate. Research was conducted to evaluate differences in properties of β-glucan in the treated versus untreated oat groats. Two oat cultivars (Rockford and Souris) were grown at Minot and Prosper, North Dakota in 2015, and glyphosate was sprayed during the soft dough stage, physiological maturity stage, or not applied. β-Glucan viscosity was not significantly (p > 0:05) affected by treatment at soft dough or physiological maturity stages. Use of glyphosate at the soft dough stage significantly (p < 0:05) reduced the percentages of β-glucan content and solubility versus untreated samples. Treatment at soft dough and physiological maturity stages significantly (p < 0:05) increased β-glucan molecular weights compared to untreated controls. Therefore, glyphosate can be applied at the physiologically mature stage of grain development because β glucan properties from the groats were not negatively affected.

The aim of the thesis is to provide solutions to the problems associated with the over-reliance of glyphosate herbicide application resulting in the emergence of resistant weeds like Chloris virgata grass and the consequent problem of glyphosate mobility in different soil environments. Chloris.virgata is an emerging problem in central Queensland and northern New South Wales. I hypothesised that mung bean and sorghum crops could suppress C.virgata at narrower row spacings and higher densities. Pot experiments were established for two seasons in a glasshouse. The data from experiments indicated maximum C.virgata biomass of 43-48g dry weight in both seasons, which was significantly reduced by 74 % when surrounded by 5-6 mung bean plants m-2. Similarly, field experiments in two seasons indicated sorghum as a better competitor than C.virgata. Significant reductions in C.virgata biomass were observed when surrounded by 10 sorghum plants m-2 in rows spaced 50 cm apart in comparison to 75 and 100 cm spacings. To study the problem of glyphosate mobility, the sorption behaviour of glyphosate in four contrasting soil types (Oxisol, Vertisol, Entisol, Inceptisol) amended with aged wood biochar was examined. Batch experiments were conducted using14C labelled glyphosate and liquid scintillation counting. Significant differences in biochar amended and unamended soils were only found in the Entisol soil system. The sorption behaviour of glyphosate in soil systems was the Oxisol>Vertisol>Entisol>Inceptisol. The Oxisol soil system was found to adsorb five times more glyphosate than the Inceptisol. Inceptisol soil systems showed the lowest amount of glyphosate sorption among all the soils. From the sorption studies, it was clear that the impact of biochar application was soil specific. Biochar can sorb glyphosate in Entisols and Inceptisols but application in Vertisols and Oxisols is ineffective. My thesis found that the strategies of biochar application and crop competition can contribute to overcoming some of the problems related to over-application of glyphosate.

Glyphosate-based herbicides (GBHs) are the most globally used herbicides raising the risk of environmental exposition. Carcinogenic effects are only one component of the multiple adverse health effects of Glyphosate and GBHs that have been reported. Questions related to hazards and corresponding risks identified in relation to endocrine disrupting effects are rising. The present study investigated the possible reproductive/developmental toxicity of GBHs administered to male and female Sprague-Dawley rats under various calendar of treatment. Assessments included maternal and reproductive outcome of F0 and F1 dams exposed to GBHs throughout pregnancy and lactation and developmental landmarks and sexual characteristics of offspring. The study was designed in two stages. In the first stage Glyphosate, or its commercial formulation Roundup Bioflow, was administered to rats at the dose of 1.75 mg/kg bw/day (Glyphosate US Acceptable Daily Intake) from the prenatal period until adulthood. In the second stage, multiple toxicological parameters were simultaneously assessed, including multigeneration reproductive/developmental toxicity of Glyphosate and two GBHs (Roundup Bioflow and Ranger Pro). Man-equivalent doses, beginning from 0.5 mg/kg bw/day (ADI Europe) up to 50 mg/kg bw/day (NOAEL Glyphosate), were administered to male and female rats, covering specific windows of biological susceptibility. The results of stage 1 and preliminary data from stage 2 experiments characterize GBHs as probable endocrine disruptors as suggested by: 1) androgen-like effects of Roundup Bioflow, including a significant increase of anogenital distances in both males and females, delay of first estrous and increased testosterone in females; 2) slight puberty onset anticipation in the high dose of Ranger Pro group, observed in the F1 generation treated from in utero life until adulthood; 3) a delayed balano-preputial separation achievement in the high dose of Ranger Pro-treated males exposed only during the peri-pubertal period, indicating a direct and specific effect of GBHs depending on the timing of exposure.

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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.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
O efeito de substâncias que em altas doses causa efeitos tóxicos, mas que em subdoses pode estimular a planta é conhecido como hormesis, sendo o glyphosate um herbicida com este efeito. Subdoses de glyphosate podem estimular o crescimento de uma diversidade de espécies de plantas, e tal resultado provavelmente esteja relacionado com o sítio de ação do glyphosate, uma vez que o efeito não é observado em plantas resistentes ao glyphosate. Diante disso, o presente trabalho teve como objetivo avaliar o efeito de hormesis do herbicida glyphosate em cana-de-açúcar e eucalipto. Para isso, foi conduzido quatros experimentos onde foram utilizados dez doses do herbicida glyphosate 0; 1,8; 3,6; 7,2; 18; 36; 72; 180; 360 e 720 g e.a.ha-1, aplicados com o auxilio de pulverizador estacionário com o volume de calda de 200 L ha-1. Nos experimentos foram avaliados a massa seca de parte aérea, fibra em detergente ácido (FDA), lignina, glyphosate, ácido chiquímico, conteúdo de clorofila, trocas gasosas (taxa de assimilação de CO2, condutância estomática e taxa de transpiração). Os resultados indicaram que a massa seca da parte aérea de cana-de-açúcar e eucalipto, apresentou incremento em doses variando de 3,6 a 18 g e.a ha-1. A aplicação de glyphosate proporcionou, em ambas as culturas, um incremento na taxa de assimilação de CO2, condutância estomática, taxa de transpiração, conteúdo de clorofila, sendo a dose variável para cada parâmetro analisado. Os níveis de FDA e lignina aumentaram em cana-de-açúcar após a aplicação de glyphosate, em todas as doses analisadas. Em resultados para eucalipto os níveis de FDA e lignina mantiveram-se estáveis, diminuindo em doses maiores. O herbicida glyphosate só foi detectado em cana-de-açúcar e eucalipto em doses a partir de 72 g e.a ha-1, da mesma forma os níveis de ácido chiquímico aumentaram.
The effect of substances that at high doses cause toxic effects, but in low doses can stimulate the plant is known hormesis. One herbicide which has been used for this purpose is glyphosate. Low doses of glyphosate can stimulate the growth of a variety of plant species, and such a result is probably related to glyphosate site of action, since the effect is not observed in glyphosate resistant plants. Therefore, this study aimed to evaluate the hormesis effect of glyphosate herbicide in sugarcane and eucalyptus. For this, it conducted four experiments where was used ten doses of glyphosate 0; 1.8; 3.6; 7.2; 18; 36; 72; 180; 360 and 720 g e.a. ha-1 , applied to the steady spray of aid with the spray volume of 200 L ha -1 . In the experiments were evaluated: dry mass of shoots, acid detergent fiber (ADF), lignin, glyphosate, shikimic acid, chlorophyll content, gas exchange (CO2 assimilation rate, stomatal conductance and transpiration rate). The results indicated that the dry mass of shoots of sugarcane and eucalyptus, increase in doses ranging from 3.6 to 18 g e.a. ha -1 . The application of glyphosate provided in both cultures, an increase in CO2 assimilation rate, stomatal conductance, transpiration rate, chlorophyll content, with variable dose for each parameter analyzed. FDA and lignin levels increased in sugarcane after application of glyphosate at all doses tested. In results to eucalyptus the FDA and lignin levels remained stable, decreasing at higher doses. The herbicide glyphosate was only detected in sugarcane and eucalyptus in doses above 72 g ha-1 , as the shikimic acid levels increased at the same way.

Orientador: Caio Antonio Carbonari
Banca: Edivaldo Domingues Velini
Banca: Fernando Tadeu de Carvalho
Resumo: O efeito de substâncias que em altas doses causa efeitos tóxicos, mas que em subdoses pode estimular a planta é conhecido como hormesis, sendo o glyphosate um herbicida com este efeito. Subdoses de glyphosate podem estimular o crescimento de uma diversidade de espécies de plantas, e tal resultado provavelmente esteja relacionado com o sítio de ação do glyphosate, uma vez que o efeito não é observado em plantas resistentes ao glyphosate. Diante disso, o presente trabalho teve como objetivo avaliar o efeito de hormesis do herbicida glyphosate em cana-de-açúcar e eucalipto. Para isso, foi conduzido quatros experimentos onde foram utilizados dez doses do herbicida glyphosate 0; 1,8; 3,6; 7,2; 18; 36; 72; 180; 360 e 720 g e.a.ha-1, aplicados com o auxilio de pulverizador estacionário com o volume de calda de 200 L ha-1. Nos experimentos foram avaliados a massa seca de parte aérea, fibra em detergente ácido (FDA), lignina, glyphosate, ácido chiquímico, conteúdo de clorofila, trocas gasosas (taxa de assimilação de CO2, condutância estomática e taxa de transpiração). Os resultados indicaram que a massa seca da parte aérea de cana-de-açúcar e eucalipto, apresentou incremento em doses variando de 3,6 a 18 g e.a ha-1. A aplicação de glyphosate proporcionou, em ambas as culturas, um incremento na taxa de assimilação de CO2, condutância estomática, taxa de transpiração, conteúdo de clorofila, sendo a dose variável para cada parâmetro analisado. Os níveis de FDA e lignina aumentaram em cana-de-açúcar após a aplicação de glyphosate, em todas as doses analisadas. Em resultados para eucalipto os níveis de FDA e lignina mantiveram-se estáveis, diminuindo em doses maiores. O herbicida glyphosate só foi detectado em cana-de-açúcar e eucalipto em doses a partir... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The effect of substances that at high doses cause toxic effects, but in low doses can stimulate the plant is known hormesis. One herbicide which has been used for this purpose is glyphosate. Low doses of glyphosate can stimulate the growth of a variety of plant species, and such a result is probably related to glyphosate site of action, since the effect is not observed in glyphosate resistant plants. Therefore, this study aimed to evaluate the hormesis effect of glyphosate herbicide in sugarcane and eucalyptus. For this, it conducted four experiments where was used ten doses of glyphosate 0; 1.8; 3.6; 7.2; 18; 36; 72; 180; 360 and 720 g e.a. ha-1, applied to the steady spray of aid with the spray volume of 200 L ha -1 . In the experiments were evaluated: dry mass of shoots, acid detergent fiber (ADF), lignin, glyphosate, shikimic acid, chlorophyll content, gas exchange (CO2 assimilation rate, stomatal conductance and transpiration rate). The results indicated that the dry mass of shoots of sugarcane and eucalyptus, increase in doses ranging from 3.6 to 18 g e.a. ha -1 . The application of glyphosate provided in both cultures, an increase in CO2 assimilation rate, stomatal conductance, transpiration rate, chlorophyll content, with variable dose for each parameter analyzed. FDA and lignin levels increased in sugarcane after application of glyphosate at all doses tested. In results to eucalyptus the FDA and lignin levels remained stable, decreasing at higher doses. The herbicid... (Complete abstract click electronic access below)
Mestre