by Tsui Tsz Ki, Martin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 119-138). / Abstracts in English and Chinese. / Acknowledgements --- p.I / Abstract --- p.III / Table of Contents --- p.VII / List of Tables --- p.XII / List of Figures --- p.XIV / Abbreviations --- p.XVI / Chapter Chapter 1 --- General Introduction / Chapter 1.1 --- Research Background --- p.1 / Chapter 1.1.1 --- General description of glyphosate --- p.1 / Chapter 1.1.2 --- Physical and chemical properties of glyphosate --- p.2 / Chapter 1.1.3 --- Commercial formulations based on glyphosate --- p.3 / Chapter 1.1.4 --- Overview of ecotoxicological studies of glyphosate-based formulations --- p.4 / Chapter 1.1.4.1 --- Aquatic toxicity of glyphosate-based formulations --- p.4 / Chapter 1.1.4.2 --- Environmental fate of glyphosate-based formulations in waters --- p.12 / Chapter 1.1.5 --- Interaction of glyphosate and other substances --- p.14 / Chapter 1.2 --- Overview of Aquatic and Sediment Toxicology --- p.16 / Chapter 1.2.1 --- Aquatic toxicology --- p.16 / Chapter 1.2.2 --- Introduction to sediment toxicology --- p.19 / Chapter 1.3 --- "Significance, Outline and Objectives of the Present Study" --- p.20 / Chapter 1.3.1 --- Significance of the research --- p.20 / Chapter 1.3.2 --- Thesis outlines and research objectives --- p.22 / Chapter Chapter 2 --- Aquatic Toxicity of Glyphosate-based Herbicides to Different Organisms and the Effects of Environmental Factors / Chapter 2.1 --- Introduction --- p.25 / Chapter 2.2 --- Materials and Methods --- p.26 / Chapter 2.2.1 --- Test organisms --- p.26 / Chapter 2.2.2 --- Test chemicals --- p.27 / Chapter 2.2.3 --- Comparison between different organisms --- p.27 / Chapter 2.2.4 --- Environmental factors in modifying Roundup® toxicity --- p.30 / Chapter 2.2.5 --- Analysis of glyphosate concentration --- p.31 / Chapter 2.2.6 --- Validity of tests and statistical analyses --- p.32 / Chapter 2.3 --- Results --- p.32 / Chapter 2.3.1 --- Comparison between different groups of organisms --- p.32 / Chapter 2.3.2 --- Environmental factors in modifying Roundup® toxicity to C.dubia --- p.35 / Chapter 2.4 --- Discussion --- p.36 / Chapter 2.4.1 --- Toxicity of glyphosate to photo synthetic organisms --- p.36 / Chapter 2.4.2 --- pH-associated toxicity of glyphosate --- p.37 / Chapter 2.4.3 --- High potency of surfactant --- p.38 / Chapter 2.4.4 --- Effects of environmental factors on Roundup® toxicity --- p.38 / Chapter 2.5 --- Conclusions --- p.39 / Chapter Chapter 3 --- "Toxicity of Rodeo®, Roundup® Biactive and Roundup® to Water-column and Benthic Organisms and the Effect of Organic Carbon on Sediment Toxicity" / Chapter 3.1 --- Introduction --- p.41 / Chapter 3.2 --- Materials and Methods --- p.43 / Chapter 3.2.1 --- Test chemicals --- p.43 / Chapter 3.2.2 --- Test organisms --- p.43 / Chapter 3.2.3 --- Toxicities to water-column and benthic organisms --- p.44 / Chapter 3.2.4 --- Effect of sediment organic carbon --- p.45 / Chapter 3.2.5 --- Statistical analyses --- p.48 / Chapter 3.3 --- Results --- p.48 / Chapter 3.3.1 --- Toxicities to water-column and benthic organisms --- p.48 / Chapter 3.3.2 --- Effect of sediment organic carbon --- p.49 / Chapter 3.4 --- Discussion --- p.54 / Chapter 3.4.1 --- Different sensitivities between water-column and bethic animals --- p.54 / Chapter 3.4.2 --- Relative toxicities of three herbicides --- p.56 / Chapter 3.4.3 --- Route of exposure of herbicides in sediment to organisms --- p.57 / Chapter 3.4.4 --- Sediment toxicity of glyphosate-based formulations --- p.58 / Chapter 3.4.5 --- Effect of organic carbon on partitioning and toxicity --- p.60 / Chapter 3.5 --- Conclusions --- p.61 / Chapter Chapter 4 --- Joint Toxicity of Glyphosate and Several Selected Environmental Pollutants to Ceriodaphnia dubia / Chapter 4.1 --- Introduction --- p.63 / Chapter 4.2 --- Materials and Methods --- p.65 / Chapter 4.2.1 --- Test organisms and toxicity tests --- p.65 / Chapter 4.2.2 --- Test chemicals --- p.66 / Chapter 4.2.3 --- Experiment I: Joint acute toxicity of Roundup® and nine toxicants --- p.66 / Chapter 4.2.4 --- Experiment II： Effect of IPA salt of glyphosate alone at EEC on toxicities of heavy metals --- p.67 / Chapter 4.2.5 --- Basic water properties and chemical analyses --- p.69 / Chapter 4.2.6 --- Statistical analyses --- p.70 / Chapter 4.3 --- Results --- p.70 / Chapter 4.3.1 --- General conditions and recovery for spiked chemicals --- p.70 / Chapter 4.3.2 --- Experiment I: Joint acute toxicity of Roundup® and nine toxicants --- p.71 / Chapter 4.3.3 --- Experiment II: Effect of IPA salt of glyphosate alone at EEC on toxicities of heavy metals --- p.73 / Chapter 4.4 --- Discussion --- p.75 / Chapter 4.4.1 --- Interactions of Roundup® and other toxicants --- p.75 / Chapter 4.4.2 --- Joint toxicity of dissimilar chemicals --- p.77 / Chapter 4.4.3 --- Complexation of glyphosate with metals interactions between liquid/solid phases --- p.79 / Chapter 4.5 --- Conclusions --- p.83 / Chapter Chapter 5 --- Environmental Fate of Glyphosate and its Nontarget Impact: a Case Study in Hong Kong / Chapter 5.1 --- Introduction --- p.85 / Chapter 5.2 --- Materials and Methods --- p.87 / Chapter 5.2.1 --- Description of study sites --- p.87 / Chapter 5.2.2 --- Physicochemical characteristics of different matrices --- p.88 / Chapter 5.2.3 --- Continuous weather monitoring --- p.89 / Chapter 5.2.4 --- Herbicide applications --- p.89 / Chapter 5.2.5 --- Experimental designs --- p.90 / Chapter 5.2.5.1 --- Estuarine enclosure experiment --- p.90 / Chapter 5.2.5.2 --- Freshwater pond experiment --- p.92 / Chapter 5.2.6 --- Schedule of sample collection and sample storage --- p.92 / Chapter 5.2.7 --- Sample preparation --- p.94 / Chapter 5.2.7.1 --- Water samples --- p.94 / Chapter 5.2.7.2 --- Sediment samples --- p.94 / Chapter 5.2.8 --- Sample determination --- p.95 / Chapter 5.2.8.1 --- Pre-column derivatization --- p.95 / Chapter 5.2.8.2 --- High performance liquid chromatography analyses --- p.95 / Chapter 5.2.8.3 --- Calibration of glyphosate and AMPA --- p.95 / Chapter 5.2.8.4 --- Recovery of glyphosate in spiked samples --- p.96 / Chapter 5.2.9 --- Statistical analyses --- p.96 / Chapter 5.3 --- Results --- p.96 / Chapter 5.3.1 --- Site characteristics --- p.96 / Chapter 5.3.2 --- Weather conditions during herbicide application --- p.99 / Chapter 5.3.3 --- Chemical analyses --- p.100 / Chapter 5.3.4 --- In-situ toxicity tests --- p.104 / Chapter 5.4 --- Discussion --- p.106 / Chapter 5.4.1 --- Site-specific factor affecting the environmental fate --- p.106 / Chapter 5.4.1 --- Site-specific factor affecting the environmental fate of glyphosate --- p.106 / Chapter 5.4.2 --- Glyphosate in water and sediment --- p.106 / Chapter 5.4.3 --- Homogeneity of glyphosate in surface water and sediment --- p.109 / Chapter 5.4.4 --- Effect of weather conditions on environmental fate of glyphosate --- p.109 / Chapter 5.4.5 --- Biological impact of Roundup® --- p.110 / Chapter 5.5 --- Conclusions --- p.112 / Chapter Chapter 6 --- General Conclusions --- p.113 / References --- p.119

Call number: LD2668 .T4 1985 J36 / Master of Science

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

Thesis (MScAgric)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: The aim of this study was to determine the effect of a grass herbicide, a broadleaf herbicide with some grass control capabilities, method of tillage (tine and no-tillage) at planting of wheat as well as different medic cultivars on the regeneration, dry matter (OM) production and quality of a medic pasture. The trial was conducted at Langgewens experimental farm in the Swartland wheat producing area. Nine medic cultivars of three different species were evaluated after being sprayed with either haloxyfop-R-methyl (HAL) ester or imazamox (IMI) and subjected to either a tine tillage or a no tillage treatment at planting of wheat. Soil samples were taken during January 2000 to determine the size of the medic and weed seedbank as well as the degree of dormancy in the medic seeds, while OM samples were taken throughout the growing season to determine the OM production of the different medic cultivars and weed species. OM samples taken during October 1998 on the same pasture, were used to determine the crude protein (CP) and neutral detergent fibre (NOF) content of the pasture. The samples were subjected to in vitro digestion and the digestibility of pasture CP (OCP), NOF(ONOF) and DM (DOM)were determined. Results showed that seedling establishment differed between cultivars used, herbicide treatments applied as well as the crop stage in the rotation. The cultivars produced more seedlings where IMI was applied compared to HAL as well as where the area consisted of two year pasture compared to one year pasture (1998) and one year wheat (1999). After a year of pasture and a year of wheat, cultivars Sephi and Paraggio produced the most seedlings, while Caliph and Orion produced the least. Caliph however, showed a very high degree of seed dormancy while Orion's low seedling establishment was due to its sensitivity to the IMI herbicide used. Little difference was found between the nine cultivars early in the season (July - August) with regard to cumulative OM production, except for Orion, whose growth was severely damaged by the IMI treatment. At the end of the growing season (October), the cultivar Caliph's cumulative OM production (2010.1 kg/ha) was significantly higher than all the other cultivars, except for Parabinga (1053. 4 kg/ha). Oifferent pasture samples, of which the botanical composition was known, was analysed for CP, NOF, OOM, OCP and ONOF. There was no significant difference in pasture composition during 1998 but variation in the pasture composition did however cause the IMI treatment, compared to the HAL treatment, to have a lower ONOFand OOMcontent. A modelling procedure was used to predict the pasture quality parameters (CP, NOF, OOM,OCP and ONOF) from the pasture composition (medic hay, medic pods, grassy and broadleaf weeds). This prediction of CP, NOF, OOM, ONOF and OCP from the pasture components had a relative low accuracy (49 -74.1 %) and a further refinement of this model for possible use on farms in order to improve grazing management and animal production is advised. In conclusion it could be said that broadleaf weed control caused a definite increase in medic seed and OMproduction, but Orion should not be used with an IMI herbicide. All the cultivars, except for Orion, produced enough seedlings up to the second year to ensure sustainability of the medic pasture. All the cultivars, except for Orion, produced a sufficient amount of OM early in the growing season. Caliph however, produced by far the most OM later in the growing season. A reduction of broadleaf weeds and medic pods will increase the digestibility of NOFand OMand therefore increase the quality of the pasture. Pods however are an important part of summer forage and the aim should therefore rather be to reduce the number of broadleaf weeds in the pasture. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die effek van 'n gras en breëblaar onkruiddoder (wat sekere grasse beheer), metode van bewerking tydens die saai van koring asook nege verskillende medic kultivars op die regenerasie, droë materiaal produksie en kwaliteit van medic weidings te bepaal. Die proef is gedoen op Langgewens proefplaas wat geleë is in die Swartland koring produserende gebied. Nege medic kultivars is geëvalueer nadat die weiding met of haloxyfop-R-metiel ester (HAL) of imazamox (IMI) onkruiddoders gespuit is en onderwerp is aan of 'n vlak tand of geen bewerking tydens die saai van koring. Grondmonsters is geneem in Januarie 2000 om die grootte van die medic en onkruid saadbank asook om die graad van dormansie in die verskillende medic kultivars se sade te bepaal. Droë materiaal monsters is gedurende die 2000 groeiseisoen geneem om die droë materiaal produksie van die verskillende medic kultivars asook onkruid spesies te bepaal. Droë materiaal monsters is gedurende Oktober 1998 geneem en gebruik om die ruproteïn (CP) en neutraaloplosbare vesel (NDF) inhoud van die weiding te bepaal. Die monsters is in vitro verteer en die verteerbaarheid van CP (OCP), NDF (ONOF) en droë materiaal (DOM) is bepaal. Resultate wys dat saailing vestiging verskil tussen die verskillende kultivars wat gebruik is, verskillende onkruiddoder behandelings asook die stadium van die weidings/koring. Die kultivars het meer geproduseer waar die weiding met IMI behandel is in vergelyking met waar HAL toegedien is, asook waar koring nog nie gesaai is nie. Na 'n jaar van weiding en 'n jaar van koring, het die kultivars Sephi en Paraggio die meeste saailinge, en Caliph en Orion die minste saailinge gehad. Caliph het egter 'n hoë graad van dormansie in sy saad getoon, terwyl die swak vestiging van Orion die gevolg is van die kultivar se hoë sensitiwiteit teenoor IMI. Min verskil is gevind tussen die nege kultivars, vroeg in die groei seisoen (Julie - Augustus), wat kumulatiewe droë materiaal produksie betref, behalwe vir Orion wat erg beskadig is deur die IMI behandeling. Aan die einde van die groeiseisoen (Oktober 2000) was die kumulatiewe droë materiaal produksie van die kultivar Caliph (2010.1 kg/ha) betekenisvol hoër as al die ander kultivars behalwe vir Parabinga (1053.4 kg/ha). Weidingsmonsters, waarvan die botaniese samestelling bekend was, is ontleed vir CP, NDF, DDM, DCP en DNDF. Daar is geen betekenisvolle verskille gevind in die botaniese samestelling van die weidingmonsters geneem in 1998 nie,maar die variasie in botaniese samestelling het veroorsaak dat IMI in vergelyking met HAL 'n laer DNDF and DDM inhoud het. 'n Model is opgestel wat die weidingskomponente (medic hooi, medic peule, gras en breëblaar onkruide) gebruik om die kwaliteits parameters (CP, NDF, DDM, DCP en DNDF) van die weiding te skat. Hierdie skatting van CP, NDF, DDM, DCP en DNDF deur van die weidingskomponente gebruik te maak het 'n relatiewe lae akuraatheid gehad (49 -74.1 %) en verdere verfyning van hierdie model vir moontlike gebruik op plase, ten einde weidings bestuur en diere produksie te verbeter, word voorgestel. Die gevolgtrekking kan gemaak word dat breëblaar onkruidbeheer 'n definitiewe verbetering in die medic saailing en droë materiaal produksie van die medies te weeg gebring het, maar die kultivar Orion behoort nie saam met 'n IMI gebruik te word nie. AI die getoetste kultivars, behalwe Orion, het voldoende saad oorlewing vertoon tot en met die tweede jaar van die rotasie om lewensvatbaarheid van die sisteem te verseker en alle kultivars, behalwe Orion, het voldoende droë materiaal produseer vroeg in die groeiseisoen. Caliph het egter laat in die groeiseisoen by verre die meeste droë materiaal geproduseer. 'n Vermindering in die hoeveelheid breëblaar onkruide en peule in die weiding sal tot 'n verhoging in die verteerbaarheid van NDF en DM lei en dus 'n verhoging in die kwaliteit van die weiding tot gevolg hê. Peule is egter 'n belangrike bron van voedsel aan weidende diere gedurende droë somermaande en die verbetering van weidings moet eerder gedoen word deur te poog om breëblaar onkruide te beheer.

Ce travail porte sur l'étude des conséquences des interactions sol-herbicide sur la biodégradation de deux herbicides : la mésotrione, récemment mise sur le marché et le glyphosate (RoundUp R). En effet, phénomènes d'adsorption et de biodégradation vont influer sur le devenir des herbicides dans les sols. L'utilisation d'outils analytiques complémentaires (LC/UV, LC/MS , RMN) nous a permis de proposer le premier schéma métabolique complet de dégradation de la mésotrione par une souche pure Bacillus sp. 3B6. Des études d'adsorption des deux herbicides sur divers constituants du sol (argiles cationiques et anioniques, fractions argileuses, sol) ont montré le rôle majeur du pH du milieu sur ce phénomène. La biodégradation de la mésotrione en présence d'une matrice solide n'entraîne pas de modifications des voies métaboliques mais peut, par contre, moduler les cinétiques d'apparition et de disparition des métabolites, ceux-ci pouvant interagir avec la matrice

The lack of effective broadleaf weed control represents one of the major factors having detrimental effects on growth and yield of soybeans. Broadleaf weeds are a serious threat to soybean growers in the southeastern United States. A broad range of herbicides is being used in an effort to control broadleaf weeds in soybeans, and research is still being conducted to find new herbicides that can best work for this purpose. This study involved the use of one these herbicides. It was fomesafen, 5-[2-chloro-4-trifluromethyl) phenoxy]-N-(methyl-sulfonyl)-2-nitrobenzamide, which controls a broad spectrum of broadleaf weeds in soybeans. The experiment was conducted in the summers of 1987 and 1988. Broadleaf weed control treatments with fomesafen at rates at 0.07, 0.14, 0.28, and 0.35 kg ai/ha in single early postemergence and late postemergence applications were evaluated using the herbicide with a nonionic surfactant at 0.25% and 0.50% of the solution. All treatments were compared with a check which did not receive herbicide application. Among the most common broadleaf weeds found in the area under study during the summer of 1987 were morningglories (Ipomoea spp), redroot pigweed (Amaranthus retroflexus L.), jimsonweed (Datura stramonium L.), common lambsquarters (Chenopodium album L.), carpetweed (Moliugo verticillata L.), and prickly sida (Sida spinose L.), For the summer of 1988 the most prevalent broadleaf weeds were morningglories, horsenettle (Solanum carolinense L.), horseweed [Conyza canadensis (L.), Cronq.], and prickly sida. The results of the experiment showed no significant differences between early postemergence and late postemergence treatments. There were no significant differences in broadleaf weed control in treatments which received 0.14, 0.28 and 0.35 kg ai/ha of fomesafen for either 1987 or 1988. Poor broadleaf weed control resulted with the application of fomesafen at its lowest rate (0.07 kg ai/ha). No significant differences were found in broadleaf weed control between concentration of 0.25% and 0.50% of the nonionic surfactant added to fomesafen. Statistically significant yield variation did occur among treatments in 1987. No significant differences in yields were found between any of the herbicide treatments in 1988. Soybean yields were significantly higher in 1988 than in 1987.

Orientador: Ulisses Rocha Antuniassi / Banca: Otavio Jorge Grigoli Abi-Saab / Banca: Caio Antonio Carbonari / Banca: Paulo Roberto Arbex Silva / Banca: Rone Batista de Oliveira / Resumo: A correta aplicação de produtos fitossanitários resulta em minimização de perdas, e mitigação de danos ambientais. A busca por uma operação de aplicação otimizada tornou a mistura em tanque de produtos fitossanitários uma prática comumente utilizada em todo o mundo. Entretanto, a mistura em tanque pode resultar em alterações físicas na calda, interferindo no espectro de gotas e no risco de deriva. Técnicas para redução de deriva devem ser utilizadas neste processo, especialmente na aplicação de herbicidas. Nesse contexto, este trabalho teve como objetivo avaliar o espectro de gotas e o potencial de deriva gerado por caldas contendo os herbicida 2,4-D e glyphosate em diferentes condições de misturas, aplicadas com duas pontas diferentes. Em uma formulação composta de herbicida 2,4-D sal colina incluindo uma tecnologia para redução da deriva. Esta formulação foi comparada a uma formulação convencional de 2,4-D sal dimetilamina (DMA) de maneira isolada e em pré mistura com glyphosate (sal potássico e sal dimetilamina) e uma mistura pronta (2,4-D sal colina + glyphosate sal dimetilamina). Para isto foram comparados vinte tratamentos, sendo cada tratamento representado por uma calda, constituídas das misturas ou não entre os herbicidas. As avaliações dos tratamentos foram realizadas em dois experimentos. O primeiro pulverizado com uma ponta de jato plano de uso estendido (Teejet XR 11002) e outro com uma ponta jato plano de indução de ar (Teejet AIXR 11002). A pressão de trabalho ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The correct application of pesticides results in loss minimization, and mitigation of environmental damage. The search for an optimal implementation of operation has the mixture in a practical defensive tank commonly used throughout the world. However, the tank-mix can result in physical changes in the spray solution, interferes with droplet spectrum and the risk of drift. Drift reduction techniques to be used in this process, including the application of herbicides. In this context, this study aims to evaluate the spectrum of drops and the potential drift generated by spraying solutions containing the herbicide 2,4-D and glyphosate in different conditions of mixtures applied with two different nozzles. A formulation containing 2,4-D salt choline including a technology for reduction of drift was used. This formulation was compared to a conventional formulation of 2,4-D dimethylamine salt (DMA) in isolation and premix with glyphosate (potassium salt and dimethylamine salt) and a ready mixed (2,4-D + glyphosate salt choline salt dimethylamine). Twenty treatments were compared, each treatment being represented by a spray solution consisting of mixtures of herbicides or not. The treatments were evaluated in two experiments. A sprayed with a jet nozzle extended use plan (Teejet XR 11002) and one with a nozzle jet air induction plan (Teejet AIXR 11002) both at 280 kPa. The Volumetric Median Diameter (VMD) and the percentage of droplets smaller than 105 µm (V105) were obtained from ... (Complete abstract click electronic access below) / Doutor

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

Os herbicidas ametrina e clomazone são amplamente utilizados na cultura de cana-deaçúcar, apresentam degradação essencialmente microbiana e são considerados contaminantes de solos e águas. A exposição dos microrganismos a estes xenobióticos pode resultar em dano oxidativo devido ao aumento na produção de espécies reativas de oxigênio (EROs). Este trabalho teve como objetivo analisar respostas bioquímicas e fisiológicas de dois isolados bacterianos tolerantes aos herbicidas ametrina e clomazone. As bactérias foram isoladas de solos agrícolas e a partir de estudos fisiológicos, crescimento e formação de halo, foram selecionadas duas que apresentaram maior tolerância aos herbicidas. Esses microrganismos foram cultivados em meio de cultura ágar nutriente, a 30°C, por 14 horas na presença dos herbicidas ametrina (25 mM), clomazone (9 mM), e em meio composto pelos dois herbicidas: ametrina (20 mM) + clomazone (20 mM). Essas concentrações representam as dosagens utilizadas para o cultivo de cana-deaçúcar para a aplicação pré e pós-emergência. Por meio da análise filogenética baseada no gene 16S ribossômico, o isolado bacteriano CC07 mostrou-se próximo a Pseudomonas aeruginosa, enquanto que o isolado 4C07 ficou próximo à Pseudomonas fulva. A peroxidação lipídica foi observada somente para o isolado CC07 na presença dos herbicidas em mistura. O perfil protéico foi avaliado em SDS-PAGE, o qual revelou a indução de uma nova proteína de aproximadamente 60 KDa para o isolado 4C07 na presença dos herbicidas, porém, não foram observadas diferenças significativas para o isolado CC07. A enzima superóxido dismutase (SOD) apresentou aumento significativo da atividade para ambos isolados quando expostos aos herbicidas, entretanto, diferenças na atividade da enzima catalase (CAT) não foram observadas. Para o isolado 4C07 na presença dos herbicidas foi observado aumento significativo no conteúdo de glutationa reduzida (GSH), o qual foi acompanhado pela indução de uma nova isoforma de GR (I), que respondeu especificamente ao clomazone e os herbicidas em mistura. A glutationa-S-transferase (GST) também apresentou acréscimos de atividade quando o isolado 4C07 foi exposto aos herbicidas. Porém, para o isolado CC07 as enzimas GR, GST, assim, como a GSH não apresentaram respostas significativas a presença dos herbicidas. Assim, foi possível observar que o isolado 4C07 possui um sistema antioxidante mais eficaz, quando comparado com o isolado CC07. Além disso, os resultados sugerem que as enzimas SOD, GR, GST e o composto GSH podem estar relacionados com o mecanismo de tolerância do isolado 4C07 aos herbicidas ametrina e clomazone, o que pode demonstrar uma provável adaptação aos ambientes estressantes. / The herbicides ametrina and clomazone are widely used in the sugar cane cultivation, showing essential microbial degradation, besides being considered contaminants of soil and water. The exposure of microorganisms to xenobiotics can result in oxidative damage due to increased production of reactive oxygen species (ROS). This study aimed to analyze biochemical and physiological responses of two bacterial strains tolerant to the herbicides ametrina and clomazone. The bacteria strains were isolated from agricultural soils and according to physiological studies, growth and halo formation, two of them with the most herbicide tolerance were selected. These microorganisms were grown in nutrient agar plates at 30 ° C for 14 hours in the presence of herbicides ametrina (25 mM), clomazone (9 mM), and in a medium composed by two herbicides: ametrina (20 mM) + clomazone (20 mM). These concentrations represent the concentrations used for growing sugar cane for pre and post-emergence. Through the phylogenetic analysis based on 16S ribosomal gene, the CC07 strain was close to Pseudomonas aeruginosa, while the 4C07 strain was close to Pseudomonas fulva. According to the results obtained, lipid peroxidation was only observed for CC07 strain in a medium composed by two herbicides. The protein profile was evaluated by SDS-PAGE, which revealed the induction of a new protein of approximately 60 kDa for 4C07 strain in the presence of the two herbicides, differently to that observed for CC07 strain. The activity of the enzyme superoxide dismutase (SOD) increased significantly for both strains when exposed to the herbicides, however, no differences were observed for catalase (CAT) activity. The 4C07 strain showed increase in content of reduced glutathione (GSH) in the presence of the herbicides, which was accompanied by the induction of a new isoform of GR (I). Similarly, the 4C07 strain exhibited an increase in Glutathione-S-transferase (GST) activity to herbicides exposure. However, for the CC07 strain, the GR and GST enzymes, as well as the GSH content did not exhibit differences. Thus, we observed that the 4C07 strain may have an antioxidant system more effective when compared to the CC07 strain. Moreover, the results suggest that the enzymes SOD, GR, GST and GSH content may be related to the mechanism of tolerance of 4C07 strain to ametrina and clomazone herbicides, showing the tendency to deal better and adapt to stressful environments.

Com o objetivo de estudar a eficiência de herbicidas dessecantes, o momento ideal de aplicação, a viabilidade da antecipação da colheita e seus efeitos sobre o rendimento e as qualidades fisiológica e sanitária de sementes de feijão, foi instalada uma pesquisa em Área Experimental e no Laboratório de Análise de Sementes do Departamento de Produção Vegetal da Escola Superior de Agricultura "Luiz de Queiroz" em Piracicaba - SP. Para tanto, utilizou-se o cultivar Pérola, o qual foi semeado na safra da "seca", na população aproximada de 200.000 plantas/ha. O delineamento experimental foi o de blocos casualizados com quatro repetições em esquema fatorial 5 x 5, sendo cinco herbicidas, combinados com as cinco épocas de aplicação (28, 32, 36, 40 e 44 dias após o florescimento) e uma testemunha (sem aplicação de herbicida dessecante). A análise dos dados e a interpretação dos resultados obtidos permitiram as seguintes conclusões: os herbicidas dessecantes Paraquat e Paraquat associado a Diuron proporcionaram antecipação da colheita em onze dias, sem causar danos ao rendimento e a qualidade das sementes, enquanto para Glifosate e Glifosate + uréia a antecipação foi de seis dias; os herbicidas dessecantes Paraquat e Paraquat associado a Diuron não afetaram nem o rendimento, nem a qualidade das sementes produzidas, independemente da época de aplicação; os herbicidas Glifosate e Glifosate mais uréia somente quando aplicados aos 44 dias após florescimento não afetaram a qualidade das sementes e o herbicida dessecante Glufosinato de Amônio, independentemente da época de aplicação, afetou negativamente a qualidade das sementes produzidas. / Viewing to study the efficiency of desiccant herbicides, the ideal moment for their application, the feasibility of anticipating the harvest and their effects on yield and the physiological and sanitary quality of common bean seeds, an experiment was conducted at the College of Agriculture "Luiz de Queiroz", in Piracicaba, state of São Paulo, Brazil. Seeds of the cultivar 'Pérola' were sown during the dry season so as to result in a population of 200,000 plants/hectare. The experimental design was a randomized complete block with four replications in a 5 X 5 factorial arrangement - 5 herbicides in combination with 5 moments of application (28, 32, 36, 40, and 44 days after flowering) and a control treatment (no desiccant was applied). The statistical analyses of the data and the interpretation of the results allowed the following conclusions: Paraquat and Paraquat plus Diuron permited an 11 days anticipation in the harvest with no harm to seed quality or reduction in yield. For Glyphosate and Glyphosate plus Urea the anticipation was of 6 days. Paraquat and Paraquat plus Diuron were not harmful to seed quality or caused yield reduction in none of the moments of application. Glyphosate and Glyphosate plus Urea were not harmful only when applied 44 days after flowering. Ammonium Gluphosinate was always harmful to seed quality independently on the moment of application.