The naturally occurring monoterpene 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane 1, commonly named 1,8-cineole and the major component in the leaf oil of many eucalypts, exhibits bioactivity, being potentially antimicrobial and pesticidal. A range of derivatives of 1,8-cineole and its naturally occurring isomeric analogue 1,4-cineole 2, 1-isopropyl-4-methyl-7-oxabicyclo[2.2.1]heptane, were synthesised. High-cineole eucalyptus oil, 1,8-cineole and the 1,8- and 1,4-cineole derivatives were shown to have a dose dependent pre-emergence and post-emergence herbicidal activity against radish (Raphanus sativus var. Long Scarlet), and annual ryegrass (Lolium rigidum) in laboratory bioassays. A postulated increase in activity of the ester derivatives due to metabolic cleavage into their bioactive hydroxy-cineole and carboxylic acid portions after uptake by the plant was not observed. The role of mallee eucalypts in the rehabilitation of degraded farmland in the Western Australian wheat belt, uses of eucalyptus oil and the bioactivity of essential oils and naturally occurring terpenes, with particular emphasis on eucalyptus oil and 1,8-cineole, were reviewed. The review encompasses allelopathic and herbicidal activity, insecticidal, acaricidal and antimicrobial activity. 1,8-Cineole compounds functionalised at position 3 of the cyclohexane ring and the 1,4-cineole derivatives were chemically synthesised whilst 2-endo-hydroxy-1,8-cineole was obtained as the primary metabolite of a novel bacterium grown on 1,8-cineole as sole carbon source. The bacteria were isolated by inoculating liquid growth medium containing 1,8-cineole as carbon source with aliquots of deionised water in which eucalyptus leaves had been stirred. Sequencing of its 16S rRNA gene identified the bacteria as belonging to the order Sphingomonadales, family Sphingomonadaceae and genus Sphingomonas. Growth curves for the bacterium are described and a metabolic pathway for the microbial degradation of 1,8-cineole is confirmed. Bacteria were cultured on a 20 L scale to provide sufficient 2-endo-hydroxy-1,8-cineole for the herbicidal bioassays.

Engineered nanomaterials (ENMs) are currently used in a wide range of manufacturing processes and applications thanks to the numerous technical and economic benefits derived from the incorporation of ENMs in these processes. Accompanying these benefits are the potential toxicity of ENMs to humans and the environment. Previous research has shown that ENMs display strong toxicity to plants. Earlier research suggested that physicochemical properties of ENMs such as their size, shape, and surface properties considerably affect toxicity; however, the unique physicochemical properties of ENMs affect their phytotxicity to plants is still unknown. This research evaluated the phytotoxicity of silver and gold nanoparticles to lettuce plants in both sand and hydroponic conditions by monitoring a wide range of plant physiological parameters after their exposure to these nanoparticles with two coating materials (citrate and polyvinylpyrrolidone) and three shapes (sphere, wire and plate) at 200 and 1000 µg/L concentrations. The result from lettuce in hydroponics showed that spherical silver or gold nanoparticles with both coatings did not affect biomass significantly, but both of silver and gold nanoparticles at 1000 µg/L slightly reduced the biomass compared to the control lettuce. The effect on root leakage was similar, but spherical silver nanoparticles had slightly higher damage due to root leakage than gold nanoparticles at the same concentration. The lettuce treated to citrate-coated gold nanoparticles significantly reduced chlorophyll content compared to citrate-coated silver nanoparticles. Secondly, when it came to the surface coating, the plant exposed to 1000 µg/L spherical citrate- coated silver or gold nanoparticles had higher root leakage compared to PVP-coated nanoparticles. Both of 1000 µg/L spherical citrate-coated silver nanoparticles and gold nanoparticles significantly reduced chlorophyll content compared to PVP-coated nanoparticles. Thirdly, for different shapes of PVP-coated silver nanoparticles, the plant exposed to plate shaped and sphere shaped silver nanoparticles had significantly lower biomass compared to the wire shaped silver nanoparticles. The plant exposed to spherical silver nanoparticles had the lowest chlorophyll content between plate shaped and wire shaped silver nanoparticles. In addition, the result from lettuce in sand medium showed that the biomass production and the root leakage showed no significant difference between spherical citrate-coated, spherical PVP-coated, and silver ions at 200 µg/L. In conclusion, different nanoparticles affected different physiological processes of plants differently.

With the recent development of nanotechnology, there has been increased production of engineered nanomaterials but limited containment strategies, resulting in inevitable release of a large amount of engineered nanoparticles (ENPs) in the environment. Many ENPs have potential adverse impacts on the environment, and one of the most commonly used ENPs, silver nanoparticle (AgNP), has attracted increased global concern. The current study focused on phytotoxicity of AgNPs to a model plant, Arabidopsis thaliana. Silver nanoparticles were introduced into the growth medium for the wild type A. thaliana plants and root uptake and translocation of AgNPs were examined in hydroponic growth condition. We also conducted growth stage based phenotypic analysis by growing A. thaliana throughout its life cycle in soil. The result indicated that: (1) wild type seeds germination was not affected by either AgNPs or their dissolved Ag+ ions; (2) AgNPs exposure resulted in a concentration- and size- dependent inhibition effect to the root elongation; (3) confocal and electron microscopy indicated that AgNPs could be taken up by seedling roots, yet most of AgNPs attached to the surface of seedling root cap; (4) AgNPs and their dissolved Ag+ ions at tested concentrations had little influence on the vegetative growth of A. thaliana, but they accelerated the floral development; and (5) the effect on the floral development stage reduced the quality of second-generation (F1) seeds, as indicated by their lower germination rate. In conclusion, AgNPs displayed both acute and chronic phytotoxicity to A. thaliana.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O experimento foi conduzido em condiÃÃes de sequeiro, no perÃodo de abril a setembro de 2010, na Fazenda Lavoura Seca, QuixadÃ, CE, no intuito de avaliar a eficiÃncia dos herbicidas diuron (diuron SC), pendimethalin (herbadox 500), e metolachlor (dual gold), em trÃs doses, no controle das plantas daninhas no consÃrcio mamona e feijÃo caupi e o efeito fitotÃxico desses herbicidas sobre a mamona e o feijÃo caupi. No consÃrcio utilizou-se a mamona, cv. BRS ENERGIA e o feijÃo caupi, cv. EPACE 10. As culturas foram plantadas em fileiras alternadas, com os arranjos seguintes: mamona em fileiras no espaÃamento 1,00 x 1,00 m, com uma fileira de feijÃo caupi entre duas fileiras de mamona. As fileiras de feijÃo caupi distaram 0,5 m das de mamona e as plantas dentro da fileira de 0,25 m. Os herbicidas e respectivas doses de ingrediente ativo avaliados foram: metolachor nas doses de (600 g ha-1, 1200 g ha-1 e 1800 g ha-1) diuron (1000 g ha-1, 2000 g ha-1 e 3000 g ha-1) e pendimenthalin (500 g ha-1, 1000 g ha-1 e 1500 g ha-1). Utilizou-se um delineamento experimental de blocos ao acaso, com arranjo fatorial e dois tratamentos adicionais (3x3+2) com 4 repetiÃÃes, exceto na anÃlise da matÃria seca das plantas daninhas onde utilizou-se um arranjo fatorial (3x3+1) com um tratamento adicional (testemunha sem capina). Os herbicidas diuron, pendimethalin e metolachlor foram nÃo seletivos a cultura da mamona causando atrasos na emergÃncia de plÃntulas, crescimento inicial, reduÃÃo dos estandes inicial e final, reduÃÃo da altura das plantas e decrÃscimos significativos na produtividade da cultura. No entanto, os mesmo herbicidas foram seletivos à cultura do feijÃo caupi, nÃo alterando a altura das plantas, nÃmero de vagens por planta e estande final. Quanto ao controle das plantas daninhas, avaliado atravÃs do peso da matÃria seca, os melhores resultados foram obtidos com o metolachor e diuron com destaque para a dose de 1800 g de i.a ha-1 do metolachlor, que reduziu de forma significativa o peso seco das plantas daninhas. / The experiment was conducted under rainfed conditions in the period April to September 2010, at Farm Lavoura Seca, QuixadÃ-CE, in order to evaluate the efficiency of diuron (Diuron SC), pendimethalin (herbadox 500), and metolachlor ( Dual Gold) in three doses on weed control in cowpea and castor bean intercropping and the phytotoxic effect of herbicides on the castor bean and cowpea. In the intercropping used the castor bean, cv. BRS ENERGY and the cowpea, cv. EPACE 10. The crops were planted in alternate rows, with the following arrangements: castor beans in rows with spacing 1.00 x 1.00 m, with a row of cowpea between two rows of castor oil. The rows of cowpea were far from castor 0.5 m and the plants within the row of 0.25 m. The herbicides and doses of active ingredient were: metolachor at doses (600 g ha-1, 1200 g ha-1 and 1800 g ha-1) diuron (1000 g ha-1, 2000 g ha-1 and 3000 g ha-1) and pendimenthalin (500 g ha-1, 1000 g ha-1 and 1500 g ha-1). We used a randomized block design, with factorial arrangement and two additional treatments (3x3 +2) with four replications, except in the analysis of dry matter of weeds where we used a factorial arrangement (3x3 +1) with a additional treatment (control without weeding). The herbicides diuron, metolachlor and pendimethalin were not selective castor bean crops causing delays in seedling emergence, early growth, reducing the initial and final stands, reduced plant height and significant decreases in yield. However, the same herbicides were harmless to the crop of cowpea, not changing the plant height, number of pods per plant and final stand. As for weed control as measured by the dry weight, the best results were obtained with diuron metolachor and especially a dose of 1800 g ai ha-1 of metolachlor, which significantly reduced the dry weight of weeds.

O herbicida deve ter a capacidade de controlar as plantas daninhas sem reduzir a produtividade e a qualidade da matéria-prima. Todavia, a tolerância da cana-de-açúcar pode variar com o herbicida, a dose desse produto, o genótipo da variedade, a época de aplicação (semi-seca, seca, semi-úmida e úmida), ambientes de produção, o estádio fenológico da cultura, dentre outros fatores. Visando o melhor entendimento do comportamento da cana-de-açúcar a aplicações do herbicida diuron+hexazinone+sulfometuron-methyl, avaliou-se a seletividade em diferentes estádios de desenvolvimento, em condições de campo, em casa de vegetação, e em laboratório. No campo, com início em setembro de 2013, as aplicações deste herbicida foram feitas em pré-emergência, esporão, 2 a 3 folhas e 5 a 6 folhas, comparando com o desempenho do herbicida amicarbazone, nas mesmas épocas, em canavial de segundo corte, onde avaliou-se fitotoxicidade, os parâmetros tecnológicos (fibra, pol, brix e ATR) e a produtividade. Constatou-se que mesmo com índices de fitotoxicidade altos nos diferentes estádios de desenvolvimento até 90 DAA, a produtividade não foi prejudicada a níveis significativos, bem como os parâmetros tecnológicos, quando comparados a testemunha. Na casa de vegetação, foi avaliado a seletividade do herbicida diuron+hexazinone+sulfometuron-methyl nos mesmos estádios de desenvolvimento avaliados em campo, nas variedades CTC 15, B86-7515, BR85-5536 e RB92-579. Observou-se diferenças significativas entre as variedades na variável altura em uma mesma época de aplicação, porém não refletiu na massa de matéria seca da parte aérea, a qual manteve-se semelhante entre os tratamentos. Para entendimento da fisiologia deste herbicida em cana-de-açúcar, avaliou-se a absorção e translocação ao longo do tempo, após sua aplicação nas fases de 2 a 3 e 5 a 6 folhas, onde apesar de serem detectadas diferenças significativas no quesito fitotoxicidade em ensaio de campo preliminar, tal acontecimento não pode ser justificado por diferenças no parâmetro absorção, conforme resultados do estudo. / The herbicide should be capable of controlling weeds without reducing productivity and quality of the raw material. However, the tolerance of sugarcane can vary with the herbicide, the dose of this product, the variety genotype, timing of application (semi-dry, dry, semi-wet and wet), production environments, the stadium phenological culture, among other factors. Aimed at better understanding the behavior of sugarcane to the herbicide diuron + hexazinone applications + sulfometuron-methyl, evaluated the selectivity at different stages of development in field conditions in the greenhouse and in the laboratory. In the field, starting in September 2013, the applications of this herbicide were made in pre-emergence, spur, 2-3 leaves and 5-6 leaves, compared to the performance of amicarbazone herbicide, at the same times, in the second cut cane field where phytotoxicity was evaluated, the technological parameters (fiber, pol, Brix and ATR) and productivity. It was found that with high phytotoxicity rates in different stages of development up to 90 DAA, productivity was not affected at significant levels, as well as technological parameters compared the witness. In the greenhouse, the selectivity of the herbicide diuron + hexazinone was rated + sulfometuron-methyl the same developmental stages evaluated in the field, in varieties CTC 15, RB86-7515, BR85-5536 and RB92-579. There were statistically significant differences between varieties in the variable height in the same time of application, but not reflected in the dry matter of the shoot, which remained similar between treatments. In order to understand the physiology of this herbicide in sugarcane, studies wih absorption and translocation was carried out over time, after application in the stages of 2 to 3 and 5 to 6 leaves, which despite being detected significant differences in field test for phytotoxicity such an event can not be justified by differences in absorption parameter, according to study results.

Made available in DSpace on 2014-06-11T19:22:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-05Bitstream added on 2014-06-13T20:09:09Z : No. of bitstreams: 1 abreu_ml_me_botfca.pdf: 619952 bytes, checksum: dbe831b21285a33d1914adaf5e7b4730 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A recomendação de um herbicida está condicionada a sua seletividade, ou seja, a sua capacidade de eliminar espécies vegetais indesejáveis sem promover reduções economicamente significativas, tanto na qualidade quanto na quantidade produzida pela cultura. A presente pesquisa avaliou a seletividade de herbicidas aplicados em pré e pós-emergência da cultura da mandioca cultivada considerando-se a intensidade de injuria na parte aérea, características morfológicas da planta, componentes da produtividade, produtividade e balanço de massa das raízes feculentas. Os experimentos foram instalados nos municípios de Botucatu/SP, Brasil em solo argiloso e em São Manuel/SP, Brasil em solo arenoso, no ano agrícola de 2008. Foi utilizado o delineamento em blocos ao acaso com quatro repetições, em esquema fatorial 11 X 2, sendo causa de variação dez herbicidas ametryne (1000g ha-1), clomazone (500g ha-1), ametryne + clomazone (750 + 500g ha-1) e atrazine (500g ha-1), aplicados logo após o plantio em pré-emergência da mandioca: haloxyfof-methyl (48 g ha-1), sethoxydim (200 g ha-1), fluazifop-p-butyl (100 g ha-1), quizalofop-p-ethyl (75 g ha-1), fomezafen (225 g ha-1) e bentazon (720 g ha-1), aplicados em pósemergência da cultura, mais uma testemunha capinada e duas variedades IAC14 e IAC576-70. Para a aplicação dos herbicidas foi utilizado um pulverizador costal, pressurizado a CO2 e equipado com barra de aplicação com cinco pontas Teejet XR 110 02vs espaçadas em 0,50m, com consumo de calda de 200 L ha-1. A fitotoxicidade das plantas de mandioca foi avaliada visualmente valendo-se de uma escala percentual de notas, na qual “zero” correspondeu a nenhuma injúria e “cem” a morte das plantas. Antes da colheita foram avaliadas a altura das plantas (cm), altura da primeira... / The herbicide recommendation is subjected to its selectivity and ability to eliminate undesirable species without promoting economically significant reductions in both quality and crop production. Thus, this work aimed to test the selectivity of herbicides applied in pre-and post-emergence of cassava crop considering the intensity of injury in the shoot, components of productivity, productivity end balance of mass of roots starch. The experiments were conducted in Botucatu / SP, Brazil, in a clay soil and São Manuel / SP, Brazil, in sandy soil, in 2008 croprowing season. The treatments was combinated in a 11 X 2 factorial (11 herbicides and 2 varieties) and disposed in a randomized block design. The treatments the herbicides tested was ametryne (1000g ha-1), clomazone (500 g ha-1), ametryne + clomazone (750 + 500 g ha-1 ) and atrazine (500 g ha-1) applied in pre-emergence of cassava,haloxyfof-methyl (48 g ha-1), sethoxydim (200 g ha-1), fluazifop-p-butyl (100 g ha-1), quizalofop-p-ethyl (75 g ha-1), fomezafen (225 g ha-1) and bentazon (720 g ha-1), applied post-emergence of culture as well as an control untreated end two varieties IAC14 and IAC576-70. For the implementation it was used a backpack sprayer, pressurized CO2 and equipped with bar application with five Teejet XR 110 02vs spaced at 0.50 m, with consumption volume of 200 L ha-1 of water. The phytotoxicity of the cassava plants was visually drawing on a percentage scale of notes, where zero corresponds to no injury and 100 % the death of plants. Before harvest were evaluated plant height (cm), height of first branch (cm), stem diameter (cm), final plant stand per hectare, the average number of stems per plant. After harvesting were assessed green mass shoot and the strains (t ha-1), shoots and strains dry... (Complete abstract click electronic access below)

Com o objetivo de avaliar a maneira como a aplicação foliar no estádio fenológico V5, do herbicida pós-emergente Lactofen em mistura com os micronutrientes Co e Mo, pode interferir com o crescimento e a produtividade da cultura da soja, cv. Conquista, o presente trabalho de pesquisa foi conduzido em duas áreas experimentais da Escola Superior de Agricultura \"Luiz de Queiroz\" (USP/ESALQ), em Piracicaba-SP: uma na Fazenda Areão, durante os anos agrícolas de 2003/04, 2004/05 e 2005/06 em solo LATOSSOLO VERMELHO Distrófico argiloso e outra na Estação Experimental de Anhembi, durante os anos agrícolas 2003/04 e 2005/06 em solo LATOSSOLO AMARELO Distrófico típico. Delineado experimentalmente sob blocos ao acaso com quatro repetições, os onze tratamentos constaram de diferentes formas de aplicação e interações entre os micronutrientes Co e Mo e o herbicida pós-emergente Lactofen: T1 = controle; T2 = tratamento de sementes com Co e Mo; T3 = tratamento de sementes com Co e Mo + aplicação de herbicida em V5; T4 = aplicação foliar de Co e Mo em V5; T5 = aplicação foliar de Co e Mo + herbicida em V5; T6 = aplicação de herbicida em V5 + foliar de Co e Mo 3 a 5 dias após; T7 = aplicação foliar de Co e Mo em V5 + aplicação de herbicida 3 a 5 dias após; T8 = aplicação foliar de Co em V5; T9 = aplicação foliar de Co + herbicida em V5; T10 = aplicação foliar de Mo em V5; T11 = aplicação foliar de Mo + herbicida em V5; Os parâmetros avaliados foram: pH das soluções de Lactofen e de micronutrientes; avaliação da fitotoxicidade causada pelo herbicida Lactofen; análise do estado nutricional das plantas em N, Co e Mo; altura final de planta; altura de inserção da primeira vagem; número de ramificações; número de vagens e de grãos por planta; grau de acamamento; peso de 1000 grãos e produtividade agrícola. Concluiu-se que: a) fornecimento de cobalto e molibdênio para a soja, cultivar Conquista, via tratamento de sementes ou via foliar, a partir de sais desses micronutrientes, pode diminuir o peso de mil grãos e a produtividade agrícola da cultura; b) a aplicação foliar do herbicida Lactofen no estádio fenológico V5 da soja, cultivar Conquista, pode interferir negativamente com o crescimento vegetativo, resultando na redução da altura final de planta, do peso de mil grãos e da produtividade agrícola da cultura; c) a aplicação foliar do herbicida Lactofen no estádio fenológico V5 da cultura da soja causa fitotoxicidade às folhas, em grau variável de leve a médio. / The purpose of this work was to evaluate how foliar applications of the post-emergence herbicide Lactofen mixed with the micronutrients Co and Mo at V5 phenological stage influence the growth and productivity of soybean, cv. Conquista. The study was conducted in two experimental areas of Escola Superior de Agricultura \"Luiz de Queiroz\" (USP/ESALQ), Piracicaba-SP. One of them was located in the Areão Farm, in a clay Oxisol, during the crop years 2003/04, 2204/05 and 2005/06. The other was located in the Anhembi Experimental Station, in an Oxisol, during the crop years of 2003/04 and 2005/06. The eleven treatments tested involved different application procedures and interactions between the micronutrients Co and Mo and the post-emergence herbicide Lactofen in a randomized block design, with four replicates. Treatments were T1 = control; T2 = seeds treated with Co and Mo; T3 = seeds treated with Co and Mo + herbicide application at V5 stage; T4 = foliar-applied Co and Mo at V5 stage; T5 = foliar-applied Co and Mo + herbicide application at V5 stage; T6 = herbicide application at V5 stage + foliar-applied Co and Mo 3 to 5 days after herbicide application; T7 = foliar-applied Co and Mo at V5 stage + herbicide application 3 to 5 days after micronutrients application; T8 = foliar-applied Co at V5 stage; T9 = foliar-applied Co + herbicide application at V5 stage; T10 = foliar-applied Mo at V5 stage; T11 = foliar-applied Mo + herbicide application at V5 stage. The parameters evaluated were: pH of Lactofen and micronutrient solutions; phytotoxicity caused by Lactofen; analysis of plant nutritional state regarding N, Co and Mo; final plant height; insertion height of the first pod; number of branches per plant; number of pods and grains per plant; lodging level; mass of 1,000 grains and yield. It was concluded that: a) the application of Co and Mo salts to soybean, cv. Conquista, whether foliar applied or used in seed treatment, may reduce the mass of 1,000 grains and crop productivity; b) the foliar application of Lactofen to soybean, cv. Conquista, at V5 phenological stage may affect the vegetative growth negatively, reducing the plant final height, the mass of 1,000 grains and the yield; c) the foliar application of Lactofen to soybean at V5 V5 phenological stage leads to leaf phytotoxicity at mild to moderate levels.

Com o objetivo de avaliar a maneira como a aplicação foliar no estádio fenológico V5, do herbicida pós-emergente Lactofen em mistura com os micronutrientes Co e Mo, pode interferir com o crescimento e a produtividade da cultura da soja, cv. Conquista, o presente trabalho de pesquisa foi conduzido em duas áreas experimentais da Escola Superior de Agricultura \"Luiz de Queiroz\" (USP/ESALQ), em Piracicaba-SP: uma na Fazenda Areão, durante os anos agrícolas de 2003/04, 2004/05 e 2005/06 em solo LATOSSOLO VERMELHO Distrófico argiloso e outra na Estação Experimental de Anhembi, durante os anos agrícolas 2003/04 e 2005/06 em solo LATOSSOLO AMARELO Distrófico típico. Delineado experimentalmente sob blocos ao acaso com quatro repetições, os onze tratamentos constaram de diferentes formas de aplicação e interações entre os micronutrientes Co e Mo e o herbicida pós-emergente Lactofen: T1 = controle; T2 = tratamento de sementes com Co e Mo; T3 = tratamento de sementes com Co e Mo + aplicação de herbicida em V5; T4 = aplicação foliar de Co e Mo em V5; T5 = aplicação foliar de Co e Mo + herbicida em V5; T6 = aplicação de herbicida em V5 + foliar de Co e Mo 3 a 5 dias após; T7 = aplicação foliar de Co e Mo em V5 + aplicação de herbicida 3 a 5 dias após; T8 = aplicação foliar de Co em V5; T9 = aplicação foliar de Co + herbicida em V5; T10 = aplicação foliar de Mo em V5; T11 = aplicação foliar de Mo + herbicida em V5; Os parâmetros avaliados foram: pH das soluções de Lactofen e de micronutrientes; avaliação da fitotoxicidade causada pelo herbicida Lactofen; análise do estado nutricional das plantas em N, Co e Mo; altura final de planta; altura de inserção da primeira vagem; número de ramificações; número de vagens e de grãos por planta; grau de acamamento; peso de 1000 grãos e produtividade agrícola. Concluiu-se que: a) fornecimento de cobalto e molibdênio para a soja, cultivar Conquista, via tratamento de sementes ou via foliar, a partir de sais desses micronutrientes, pode diminuir o peso de mil grãos e a produtividade agrícola da cultura; b) a aplicação foliar do herbicida Lactofen no estádio fenológico V5 da soja, cultivar Conquista, pode interferir negativamente com o crescimento vegetativo, resultando na redução da altura final de planta, do peso de mil grãos e da produtividade agrícola da cultura; c) a aplicação foliar do herbicida Lactofen no estádio fenológico V5 da cultura da soja causa fitotoxicidade às folhas, em grau variável de leve a médio. / The purpose of this work was to evaluate how foliar applications of the post-emergence herbicide Lactofen mixed with the micronutrients Co and Mo at V5 phenological stage influence the growth and productivity of soybean, cv. Conquista. The study was conducted in two experimental areas of Escola Superior de Agricultura \"Luiz de Queiroz\" (USP/ESALQ), Piracicaba-SP. One of them was located in the Areão Farm, in a clay Oxisol, during the crop years 2003/04, 2204/05 and 2005/06. The other was located in the Anhembi Experimental Station, in an Oxisol, during the crop years of 2003/04 and 2005/06. The eleven treatments tested involved different application procedures and interactions between the micronutrients Co and Mo and the post-emergence herbicide Lactofen in a randomized block design, with four replicates. Treatments were T1 = control; T2 = seeds treated with Co and Mo; T3 = seeds treated with Co and Mo + herbicide application at V5 stage; T4 = foliar-applied Co and Mo at V5 stage; T5 = foliar-applied Co and Mo + herbicide application at V5 stage; T6 = herbicide application at V5 stage + foliar-applied Co and Mo 3 to 5 days after herbicide application; T7 = foliar-applied Co and Mo at V5 stage + herbicide application 3 to 5 days after micronutrients application; T8 = foliar-applied Co at V5 stage; T9 = foliar-applied Co + herbicide application at V5 stage; T10 = foliar-applied Mo at V5 stage; T11 = foliar-applied Mo + herbicide application at V5 stage. The parameters evaluated were: pH of Lactofen and micronutrient solutions; phytotoxicity caused by Lactofen; analysis of plant nutritional state regarding N, Co and Mo; final plant height; insertion height of the first pod; number of branches per plant; number of pods and grains per plant; lodging level; mass of 1,000 grains and yield. It was concluded that: a) the application of Co and Mo salts to soybean, cv. Conquista, whether foliar applied or used in seed treatment, may reduce the mass of 1,000 grains and crop productivity; b) the foliar application of Lactofen to soybean, cv. Conquista, at V5 phenological stage may affect the vegetative growth negatively, reducing the plant final height, the mass of 1,000 grains and the yield; c) the foliar application of Lactofen to soybean at V5 V5 phenological stage leads to leaf phytotoxicity at mild to moderate levels.

Poplar (Populus deltoides x nigra DN34) tissue cultures removed 2,4,6-trinitrotoluene (TNT) from an aqueous solution in five days, reducing the toxicity of the solution from highly toxic Microtox® EC value to that of the control. 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) was taken up by the plant tissue cultures more slowly, but toxicity reduction of the solution was evident. The measurement of toxicity reduction of aqueous solutions containing TNT and RDX was performed using a novel methodology developed for use with the Microtox® testing system. Radiolabeled TNT and RDX were used to confirm removal of explosives from hydroponic solutions containing plant tissue cultures and to verify that toxicity did not change in solutions where no plant cultures were present (positive controls). High Performance Liquid Chromatography (HPLC) and Liquid Scintillation Counter (LSC) measurements confirmed removal of TNT and RDX from solutions containing poplar plant tissue cultures and constancy of the plant-free controls. In addition, metabolites were identified in remediated solutions by HPLC, confirming the mechanism by which plants can remediate groundwater, surface water, and soil solutions. Using an Affymetrix® microarray, poplar trees were exposed to TNT over 48 hours. General patterns, as well as significant downregulated and upregulated genes were studied. We identified several new genes that were implicated in the detoxification and metabolism of TNT by Populus. In particular, our results support the "green liver" model of different gene families being expressed during the time course experiments. This suggests an alignment with Phase I transformation, Phase II conjugation, and Phase III compartmentation processes. Many of the genes identified in this study were related to those significantly expressed in previous Arabidopsis studies, supporting the comparison between these two plants. Gene families represented as significant in this study were glucosyltransferases, glycosyltransferases, cytochromes, and phosphofructokinases. We saw patterns in the areas of respiration, citric acid cycle, shikimatic pathway, and toxic responses.

Oil sands operators are being faced with the challenge of reclaiming the large volumes of slurry tailings created during oil sands processing. New regulations mandate that operators must minimize fluid tailings by capturing fines in dedicated disposal areas, leading to a ‘trafficable’ or solid deposit. Adding a polyacrylamide polymer to the tailings and thinly spreading them over a sloped disposal area (a process developed by Shell Canada Energy known as the atmospheric fines drying or AFD process) has been shown to enhance the dewatering of tailings which leads to a dry deposit at a much faster rate than traditional methods. Hydroponic experiments using the emergent aquatic macrophytes cattail (Typha latifolia L.) and common reed (Phragmites australis (Cav.) Trin. ex Steud.) were conducted to investigate the phytotoxicity of waters formed during AFD processing. The phytotoxicity of AFD release waters was compared to the phytotoxicity of traditional mature fine tailings (MFT) reclaim water through the monitoring of plant water uptake and whole plant fresh weight over the course of the experiment. It was found that there are no significant differences between the phytotoxicity observed in the MFT and AFD treatments and it was also found that spring runoff melt water from the AFD deposits is less phytotoxic than the original release water. Two additional hydroponic studies using cattail and common reed were also conducted. The first examined the phytotoxic effects attributable solely to the naphthenic acids isolated from Shell’s Muskeg River Mine tailings, and the second evaluated the phytotoxic effects of amending mature fine tailings with gypsum. It was found that the gypsum amended tailings caused greater phytotoxicity in cattail and common reed than tailings without gypsum added. Furthermore, both species were tolerant to growing in nutrient media spiked with naphthenic acids (40 mg/L). The phytotoxicity experiments conducted also demonstrated that common reed is consistently more tolerant to growing in water associated with oil sands tailings and is therefore the more appropriate choice for use in reclamation strategies involving wetland plants. Mass spectrometry was used to determine the naphthenic acid molecular profiles for Shell oil sands tailings. Using low resolution mass spectrometry, no detectable features or changes to the composition of naphthenic acids attributable to Shell processing were found. High-resolution mass spectrometry provided insight into possible plant mediated changes and biodegradation of naphthenic acids. It appears as though, to some extent, cattail is able to dissipate naphthenic acids, which could explain the susceptibility of cattail to the phytotoxic effects of naphthenic acids. Further research is required to determine whether the changes observed in the naphthenic acid mixture are due to microbial degradation and/or a phytotoxic response of the plants studied.