Fungicide-resistance management tactics: impacts on Zymoseptoria tritici populations

Azoles and Succinate Dehydrogenase Inhibitors (SDHIs) are the main fungicides available for septoria tritici blotch control, causal agent Zymoseptoria tritici. Decline in azole sensitivity, in combination with European legislation, poses a threat to wheat production in Ireland. Azole fungicides select CYP51 mutations differentially; it was hypothesised that using combinations of azoles could be an effective anti-resistance tool. Naturally inoculated field experiments were carried out in order to understand the impacts of using combinations of azoles, epoxiconazole and metconazole, on azole sensitivity. Approximately 3700 isolates were isolated and their sensitivity to both azoles analysed. Findings showed that limiting the number of applications, by alternating each fungicide, slowed selection for reduced azole sensitivity. Limiting azole use by reducing doses did not reduce selection for decreased azole sensitivity. Although not complete, cross-resistance was observed between the two azoles, which will lead to general reduction in azole sensitivity. A sub-selection of isolates from each treatment at each location were analysed for changes in the CYP51 gene. Sequence analysis identified 49 combinations of mutations in the CYP51 gene, and three different inserts in the CYP51 promoter. Intragenic recombination also featured in these populations. Baseline studies of five new SDHIs were carried out on 209 naturally infected, non-SDHI-treated isolates. With the exception of fluopyram, cross-resistance was apparent between the SDHIs. Analysis of 2300 isolates found that when compared to the solo products, mixing the SDHI isopyrazam and the azole epoxiconazole increased epoxiconazole sensitivity, but had no apparent effect on isopyrazam sensitivity. SDHI resistance-conferring mutations were absent in the baseline and experimental isolates. As long as azoles are used, Z. tritici populations will continue to evolve towards resistance. Combining different modes-of-action, SDHIs and multi-sites, with azoles will relieve some of that selective pressure. To get the best out of available fungicides, they should be used in combination with host resistance and good crop management practices.

Photoperiod sensitivity affects flowering duration in wheat

Flowering and successful pollination in wheat are key determinants of both quantity and quality of grain. Bread wheat line ‘Paragon’, introgressed with single or multiple day length insensitivity alleles was used to dissect the effects on the timing and duration of flowering within a hierarchical plant architecture. Flowering of wheat plants was observed in a series of pot-based and field experiments. Ppd-D1a was the most potent known allele affecting the timing of flowering, requiring the least thermal time to flowering across all experiments. The duration of flowering for individual lines was dominated by the shift in the start of flowering in later tillers and the number of tillers per plant, rather than variation in flowering duration of individual spikes. There was a strong relationship between flowering duration and the start of flowering with the earliest lines flowering for the longest. The greatest flowering overlap between tillers was recorded for the Ppd-1b. Across all lines, a warmer environment significantly reduced the duration of flowering and the influence of Ppd-1a alleles on the start of flowering. These findings provide evidence of pleiotropic effects of the Ppd-1a alleles, and have direct implications for breeding for increased stress resilient wheat varieties.

Impact of cyclones on sea ice in the Fram Strait: numerical simulations and observations

The sea ice export from the Arctic is of global importance due to its fresh water which influences the oceanic stratification and, thus, the global thermohaline circulation. This study deals with the effect of cyclones on sea ice and sea ice transport in particular on the basis of observations from two field experiments FRAMZY 1999 and FRAMZY 2002 in April 1999 and March 2002 as well as on the basis of simulations with a numerical sea ice model. The simulations realised by a dynamic-thermodynamic sea ice model are forced with 6-hourly atmospheric ECMWF- analyses (European Centre for Medium-Range Weather Forecasts) and 6-hourly oceanic data of a MPI-OM-simulation (Max-Planck-Institute Ocean Model). Comparing the observed and simulated variability of the sea ice drift and of the position of the ice edge shows that the chosen configuration of the model is appropriate for the performed studies. The seven observed cyclones change the position of the ice edge up to 100 km and cause an extensive decrease of sea ice coverage by 2 % up to more than 10 %. The decrease is only simulated by the model if the ocean current is strongly divergent in the centre of the cyclone. The impact is remarkable of the ocean current on divergence and shear deformation of the ice drift. As shown by sensitivity studies the ocean current at a depth of 6 m – the sea ice model is forced with – is mainly responsible for the ascertained differences between simulation and observation. The simulated sea ice transport shows a strong variability on a time scale from hours to days. Local minima occur in the time series of the ice transport during periods with Fram Strait cyclones. These minima are not caused by the local effect of the cyclone’s wind field, but mainly by the large-scale pattern of surface pressure. A displacement of the areas of strongest cyclone activity in the Nordic Seas would considerably influence the ice transport.

Germination and survival of tetraspores of Kappaphycus alvarezii var. alvarezii (Solieriaceae, Rhodophyta) introduced in subtropical waters of Brazil

The carrageenophyte Kappaphycus alvarezii was introduced in 1995 and vegetatively propagated in Ubatuba, Sao Paulo State, Brazil, for the purpose of commercial cultivation. This species produces tetraspores mainly in the austral summer and fall. Tetraspore germination and survival were studied under different conditions of temperature, photon flux density, and photoperiod in the laboratory. Field experiments were also carried out. Although tetraspores of K. alvarezii germinated, they had low survival rates, most dying after 20 days. Recruitment of K. alvarezii tetraspores did not occur in experiments conducted in the field. The results indicated that the establishment of K. alvarezii via spore production in the natural environment of the south-east coast of Brazil is rather remote.

The Optimal trigger speed of vehicle activated signs

The thesis aims to elaborate on the optimum trigger speed for Vehicle Activated Signs (VAS) and to study the effectiveness of VAS trigger speed on drivers’ behaviour. Vehicle activated signs (VAS) are speed warning signs that are activated by individual vehicle when the driver exceeds a speed threshold. The threshold, which triggers the VAS, is commonly based on a driver speed, and accordingly, is called a trigger speed. At present, the trigger speed activating the VAS is usually set to a constant value and does not consider the fact that an optimal trigger speed might exist. The optimal trigger speed significantly impacts driver behaviour. In order to be able to fulfil the aims of this thesis, systematic vehicle speed data were collected from field experiments that utilized Doppler radar. Further calibration methods for the radar used in the experiment have been developed and evaluated to provide accurate data for the experiment. The calibration method was bidirectional; consisting of data cleaning and data reconstruction. The data cleaning calibration had a superior performance than the calibration based on the reconstructed data. To study the effectiveness of trigger speed on driver behaviour, the collected data were analysed by both descriptive and inferential statistics. Both descriptive and inferential statistics showed that the change in trigger speed had an effect on vehicle mean speed and on vehicle standard deviation of the mean speed. When the trigger speed was set near the speed limit, the standard deviation was high. Therefore, the choice of trigger speed cannot be based solely on the speed limit at the proposed VAS location. The optimal trigger speeds for VAS were not considered in previous studies. As well, the relationship between the trigger value and its consequences under different conditions were not clearly stated. The finding from this thesis is that the optimal trigger speed should be primarily based on lowering the standard deviation rather than lowering the mean speed of vehicles. Furthermore, the optimal trigger speed should be set near the 85th percentile speed, with the goal of lowering the standard deviation.

Automating condition monitoring of vegetation on railway trackbeds and embankments

Vegetation growing on railway trackbeds and embankments present potential problems. The presence of vegetation threatens the safety of personnel inspecting the railway infrastructure. In addition vegetation growth clogs the ballast and results in inadequate track drainage which in turn could lead to the collapse of the railway embankment. Assessing vegetation within the realm of railway maintenance is mainly carried out manually by making visual inspections along the track. This is done either on-site or by watching videos recorded by maintenance vehicles mainly operated by the national railway administrative body. A need for the automated detection and characterisation of vegetation on railways (a subset of vegetation control/management) has been identified in collaboration with local railway maintenance subcontractors and Trafikverket, the Swedish Transport Administration (STA). The latter is responsible for long-term planning of the transport system for all types of traffic, as well as for the building, operation and maintenance of public roads and railways. The purpose of this research project was to investigate how vegetation can be measured and quantified by human raters and how machine vision can automate the same process. Data were acquired at railway trackbeds and embankments during field measurement experiments. All field data (such as images) in this thesis work was acquired on operational, lightly trafficked railway tracks, mostly trafficked by goods trains. Data were also generated by letting (human) raters conduct visual estimates of plant cover and/or count the number of plants, either on-site or in-house by making visual estimates of the images acquired from the field experiments. Later, the degree of reliability of(human) raters’ visual estimates were investigated and compared against machine vision algorithms. The overall results of the investigations involving human raters showed inconsistency in their estimates, and are therefore unreliable. As a result of the exploration of machine vision, computational methods and algorithms enabling automatic detection and characterisation of vegetation along railways were developed. The results achieved in the current work have shown that the use of image data for detecting vegetation is indeed possible and that such results could form the base for decisions regarding vegetation control. The performance of the machine vision algorithm which quantifies the vegetation cover was able to process 98% of the im-age data. Investigations of classifying plants from images were conducted in in order to recognise the specie. The classification rate accuracy was 95%.Objective measurements such as the ones proposed in thesis offers easy access to the measurements to all the involved parties and makes the subcontracting process easier i.e., both the subcontractors and the national railway administration are given the same reference framework concerning vegetation before signing a contract, which can then be crosschecked post maintenance.A very important issue which comes with an increasing ability to recognise species is the maintenance of biological diversity. Biological diversity along the trackbeds and embankments can be mapped, and maintained, through better and robust monitoring procedures. Continuously monitoring the state of vegetation along railways is highly recommended in order to identify a need for maintenance actions, and in addition to keep track of biodiversity. The computational methods or algorithms developed form the foundation of an automatic inspection system capable of objectively supporting manual inspections, or replacing manual inspections.

Competition of sicklepod, cassia obtusifolia l., densities on soybean, glycine max (l.) merr., at variable row distance

Competition studies with soybeans, Glycine max (L.) Merr. "Bragg." and sicklepod, Cassia obtusifolia L., were conducted at the Agricultural Research and Education Center of the University of Florida in Quincy, Florida. Two field experiments were established, one on May 22, 1975. and the other four weeks later, on June 19, 1975, to determine the competitive effects of various sicklepod densities and the influences of soybean row distances on weed dry matter, soybear plant characteristics, yield components and seed yield, and on soil nutrient content. Control, low, medium, and high sicklepod densities in the first experiment were O, 25,000, 53,000, and 77,000 p1ants/ha, respectively; while the second experiment presented control, low, medium, and high sicklepod densities of O, 36,000, 68,000, and 122,000 plants/ha, respectively. Three soybean row distance treatments were tested using a constant pattern of 90-, 60-, and 45-cm widths throughout the growing season. Three other treatments, evaluated in a variable patern, were initially seeded in 30-cm row widths. Five weeks after planting, an appropriate number of soybean rows were harvested from the 30"cm pattern to establish row distances of 90, 60, and 30-60 cm for the remainder of the season. ln the greenhouse a test was conducted to evaluate the effects af those variables on seed germination and seedling vigor for the next soybean generation. As a result of full-season sicklepod competition, soybean plants were less branched, set fewer leaves, and presented thinner stems as compared to the control. However, height of soybean plants was not affected by the presence of sicklepod. ln one of the two experiments, number of nodes decreased for soybeans under weed campetition. The yield components--number of pods; number of seeds, and seed yield per soybean plant--were all similarly reduced due to weed competition. Seeds per pod were decreased to a lesser extent. Soybean seed yields per unit area were significantly diminished by increasing levels af sicklepod ínfestation. While the control produced 3120 kg/ha, the sicklepod densities of 25,000, 53,000, and 77,000 plants/ha reduced seed yíelds 47, 65, and 73%, respectively. As soybean row distances decreased, number of branches, number of leaves, and stem diameter of soybeans decreased. However, the height of soybean plants increased with narrwing of row width. The components of seed yield--number of pods, number of seeds, and seed yield per soybean plant--diminished as row spacing was reduced. Maximum difference between row distances for these attributes was attained for soybean plants under weed-free conditions. Generally, as row width decreased, soybean seed yield per unit area increased. Specifically, soybear.s in 90-cm rows, either in constant or variable row pattern, yielded less than soybeans in 60- and 30-60-cm rows in the variable pattern. Soil contents of phosphorus, potassium, calcium, and magnesium were not affected by the various levels of sicklepod and soybean populalions. Neither the sicklepod densities nor the soybean row distances influenced seed germination and seedling vigor in the next soybean generation. Sicklepod was a strong competitor with soybeans at all density ranges investigated. Because sicklepod grows taller than soybeans during the reproductive stages of the crop, limited success can be reached by varying row spacing alone. However, this practice is considered an integral measure to complement other methods of sicklepod control. Compared to constant rows, the soybean cropping system using variable row spacings presents the choice of planting soybeans at close row spacings to provide early competition with weeds and the possibility of obtaining a forage crop after the first month of growth, without any decreases on the final seed yields.

Dinâmica da água no solo em cultivos de milho sob plantio direto e preparo convencional

A dinâmica da água em sistema de plantio direto (PD) é alterada em relação ao preparo convencional (PC) devido a modificações na estrutura do solo e a presença de palha na superfície. Para avaliar estas diferenças foram conduzidos experimentos de campo, em 2001/02 e 2002/03, em Eldorado do Sul, RS. O objetivo geral foi quantificar alterações físico-hídricas no perfil e na superfície do solo em PD e PC, com ênfase na dinâmica da água e respostas das plantas de milho. Os sistemas de manejo do solo foram implantados na área em 1995. Foram avaliadas propriedades físicas, a movimentação e a armazenagem de água no solo. Mediu-se a infiltração e a capacidade de campo e monitorou-se a dinâmica da água durante o ciclo da cultura, enfocando a secagem do solo e a extração de água em períodos sem precipitação. Nestes períodos também foi determinada a evaporação da água na superfície e avaliadas respostas das plantas. Os efeitos do plantio direto se evidenciaram nas camadas de solo próximas à superfície. A mesoporosidade foi a propriedade física mais afetada, apresentando uma distribuição exponencial de mesoporos no plantio direto, enquanto no preparo convencional a mesma se aproximou de uma curva normal. Em geral, a condutividade hidráulica, a retenção e a disponibilidade de água foram mais elevadas em plantio direto, principalmente, próximo à superfície. O solo em PD também apresentou maior umidade volumétrica com menor energia de retenção, resultando em redução no avanço da frente de secagem do solo e extração de água. A evaporação também foi maior em PD, demonstrando que a maior umidade no solo em plantio direto se deve ao aumento na capacidade de armazenagem de água. O aprofundamento radicular foi sempre maior no preparo convencional. O plantio direto altera propriedades físicas ligadas à dinâmica da água, proporcionando maior disponibilidade hídrica no solo ao longo do tempo.

Integração de características de planta, de dossel e de solo para maior eficiência da adubação nitrogenada em cobertura em milho

O milho é um das culturas mais exigentes em nitrogênio (N). A sua aplicação na dose e época correta pode aumentar a sua eficiência de uso, diminuindo custos e danos ambientais. Foram estudadas características de planta, de dossel e de solo, como indicadores da disponibilidade de N no sistema solo-planta para predição da necessidade deste nutriente em cobertura em milho. Foram conduzidos cinco experimentos a campo e dois em casa de vegetação, nas estações de crescimento de 2002/03 e 2003/04, na Estação Experimental Agronômica e na Faculdade de Agronomia da UFRGS, em Eldorado do Sul e em Porto Alegre-RS, Brasil, respectivamente, e dois experimentos a campo no ano de 2004 no Estern Cereal and Oilseed Research Center, em Ottawa-Ontário, Canadá. Foram avaliadas, em diferentes locais e situações de manejo, características de planta, de dossel e de solo, citando-se: teores de nitrato, amônio e N mineral no solo e na folha; massa seca e área foliar da folha e da planta, teor e acúmulo de N na folha e na planta; teor relativo de clorofila na folha, medido pelo clorofilômetro, reflectância do dossel, medido por dois tipos de radiômetros e fluorescência da folha, medida pelo fluorômetro. Além disso, foram avaliados o rendimento de grãos e seus componentes e parâmetros de eficiência técnica e econômica de uso de N. Dentre as características de planta, o teor relativo de clorofila na folha, e dentre os de solo, o teor de nitrato no solo, destacaram-se entre os demais avaliados. Foram determinados níveis críticos e doses ótimas de N, bem como estabelecidas curvas de calibração para dois níveis de manejo com base nestas características para monitoramento da lavoura. No que diz respeito às características de dossel estudadas, a reflectância apresentou melhores resultados que a fluorescência como indicador do nível de N no sistema solo-planta. Os estudos realizados mostraram que dentre as caracteríticas avaliadas, atualmente, o teor relativo de clorofila na folha tem o maior potencial para auxiliar na determinação da época mais adequada para aplicação de N em cobertura em milho.

Avaliação da produtividade de biomassa de capim elefante e sorgo sacarino no Estado do Ceará para uso energético

Com a crescente elevação nas possibilidades de utilização da biomassa nos mais diversos setores da indústria, o presente estudo visa identificar uma alternativa para aumentar a produção utilizando, para tanto, o capim elefante (Pennisetum purpureum) e sorgo sacarino (Sorghum bicolor L.). Os experimentos foram realizados na Fazenda Vitória (4°21'36"S 38°5'17"W) em Beberibe – CE, em uma área total de 1.944 m2. A semeadura foi realizada em 36 parcelas de 54 m2, em delineamento inteiramente casualizado, sendo 9 tratamentos (genótipos) e 4 repetições. Foram utilizados seis diferentes genótipos de sorgo sacarino, s_1, s_2, s_3, s_4, s_5 e s_6. Fazem parte do estudo, ainda, um híbrido de capim elefante e milheto (Pennisetum glaucum), comercialmente conhecido como paraíso, e dois tratamentos de capim elefante, Cameroon e Napier. Para o sorgo sacarino, foram realizadas três colheitas, a primeira avaliada semanalmente e as demais com avaliação única. Para o capim elefante foram realizadas duas colheitas, a primeira com intervalo de 186 dias e a segunda com intervalo de 92 dias. Esse intervalo possibilitou a comparação da produtividade de biomassa de cada tratamento de forma trimestral e semestral. Os resultados observados mostraram que os tratamentos de maior destaque de produtividade de biomassa (base seca) foram com capim elefante, independente do período. Com base nessas informações, concluiu-se que, analisando apenas a produtividade de biomassa, o mais indicado dos tratamentos estudados é o capim elefante Napier ou Cameroon. No entanto, constatou-se que o sorgo sacarino apresentou grande potencial de produtividade com um aditivo, seu mosto pode ser utilizado no processo de fermentação para obtenção do etanol.

The price of threat: the role of identity-safe marketplaces in predicting intergroup price sensitivity

In field experiments with subjects living either inside or outside Brazilian slums (n=955), we show that consumers living in slums are less price sensitive, in opposition with recent price sensitivity research. Comparing slum and non-slum dwellers, we found that negatively stereotyped consumers (e.g. slum dwellers) were more likely to pay higher amounts for friendlier customer service when facing social identity threats (SITs) in marketplaces such as banks. The mechanism which makes them less price sensitive is related to the perception of how other people evaluate their social groups, and we argue that they pay more because they are seeking identity-safe commercial relationships. This work, besides extending the literature in SITs, presents a perspective for the exchange between economics and psychology on price sensitivity, showing that consumers living in slums are willing to pay more to avoid possibly social identity threating experiences.

Sistema de sensoriamento eletromagnético utilizado para detecção da contaminação do óleo isolante do motor no método de elevação artificial do tipo bombeio centrífugo submerso

In the artificial lift method by Electrical Submersible Pump (ESP), the energy is transmitted for the well´s deep through a flat electric handle, where it is converted into mechanical energy through an engine of sub-surface, which is connected to a centrifugal pump. This transmits energy to the fluid under the pressure form, bringing it to the surface In this method the subsurface equipment is basically divided into: pump, seal and motor. The main function of the seal is the protect the motor, avoiding the motor´s oil be contaminated by oil production and the consequent burning of it. Over time, the seal will be wearing and initiates a contamination of motor oil, causing it to lose its insulating characteristics. This work presents a design of a magnetic sensor capable of detecting contamination of insulating oil used in the artificial lift method of oil-type Electrical Submersible Pump (ESP). The objective of this sensor is to generate alarm signal just the moment when the contamination in the isolated oil is present, enabling the implementation of a predictive maintenance. The prototype was designed to work in harsh conditions to reach a depth of 2000m and temperatures up to 150°C. It was used a simulator software to defined the mechanical and electromagnetic variables. Results of field experiments were performed to validate the prototype. The final results performed in an ESP system with a 62HP motor showed a good reliability and fast response of the prototype.

Influência de extratos aquosos de sorgo sobre a germinação e o desenvolvimento de plântulas de soja

Estudos conduzidos em laboratório ou em condições de campo demonstram o potencial alelopático da espécie Sorghum bicolor L., seja inibindo a germinação e o desenvolvimento de plantas daninhas ou até mesmo de plantas cultivadas em sucessão. Com o objetivo de avaliar os efeitos potencialmente alelopáticos de extratos aquosos das folhas, caules e raízes de cinco híbridos de sorgo (SARA, DKB860, DKB 599, XBG00478 e XBG06020), sobre a germinação e o desenvolvimento de plântulas de soja, cv. MG/BR 46 (Conquista), foram conduzidos dois bioensaios no período de março a junho de 2002. Foram estabelecidas como testemunhas: água destilada (com pH 8,0); água destilada com pH ajustado para 4,5; água destilada com pH ajustado para 6,0 e solução de polietilenoglicol (PEG) equivalente ao potencial osmótico de 0,1 MPa. Dentre as características avaliadas, houve efeito significativo apenas no comprimento de radícula das plântulas de soja, sendo que aquelas tratadas com os extratos de sorgo apresentaram menor radícula, diferindo significativamente das plântulas testemunhas. Observou-se que, com os extratos de raízes dos híbridos SARA, DKB860, XBG00478 e XBG06020 ocorreram os menores comprimentos de radículas de soja, diferindo do DKB 599. O extrato de folhas do XBG00478 resultou em menor média, não diferindo dos extratos de DKB860, DKB599 e XBG06020. No entanto, para o extrato de caule, o SARA resultou em menor radícula, diferindo apenas do XBG00478. Verificou-se, também, que, para os extratos de DKB860 e XBG00478, os extratos de folhas proporcionaram menor média, diferindo dos extratos de raiz e caule, enquanto para DKB599, XBG06020 e SARA, não houve diferença significativa entre os extratos de folha e caule.

Distribuição espacial de Bemisia tabaci (Genn.) biótipo B (Hemiptera: Aleyrodidae) em feijoeiro (Phaseolus vulgaris L.)

O estudo da distribuição espacial de pragas é fundamental para elaboração de planos de amostragem que possam propiciar maior adoção do manejo integrado de pragas. Para Bemisia tabaci (Genn.) biótipo B em feijoeiro Phaseolus vulgaris L., foram conduzidos ensaios de campo em uma área de 10.000 m², dividida em 100 parcelas iguais de 10 x 10 m, nas épocas de semeadura das águas e da seca. As amostragens foram realizadas semanalmente, em 10 plantas por parcela. Coletou-se um folíolo por planta e avaliou-se a presença-ausência de ninfas da mosca-branca na página abaxial. Para adultos, observou-se visualmente a presença-ausência da praga nas plantas. em todas as amostragens obtiveram-se valores menores que a unidade para a relação variância/média, indicando disposição regular da mosca-branca no campo, confirmada pelos valores significativos da estatística ½d½, do teste de afastamento da aleatoriedade, assim como pelos valores inferiores à unidade do índice de Morisita. A distribuição binomial positiva foi o modelo mais adequado para representar a distribuição espacial da B. tabaci biótipo B na cultura do feijão.

Transition metal rates in latosol twice treated with sewage sludge

A reciclagem agrícola do lodo de esgoto tem provocado o acúmulo de metais pesados no solo e na água, podendo atingir níveis tóxicos e causar danos às plantas cultivadas, aos animais e ao homem, por meio da cadeia trófica. Neste intuito foi desenvolvido o presente experimento, em condições de campo, entre 2000 e 2002, onde foram avaliados os efeitos da aplicação de lodo de esgoto por dois anos, sobre a extração de metais de transição (essenciais e não) pelo extrator DTPA em um Latossolo Vermelho distrófico (LVd) de textura média. As concentrações dos elementos metálicos: Mn, Fe, Cd, Ni, Co, Pb e Cr não foram detectados pelo método da absorção atômica na solução obtida com o extrator DTPA. A aplicação de lodo de esgoto causou inicialmente pequena elevação no pH do solo, posteriormente a diminuição do mesmo, e manteve-se próximo ao original. Foi possível concluir que, com a aplicação consecutiva do lodo, os teores extraíveis de Fe e Mn nas amostras de solos aumentaram gradativamente nos dois anos agrícolas, com as doses do lodo de esgoto aplicado, época de amostragens, e foram superiores ao tratamento testemunha. O extrator apresentou capacidade restrita para avaliação da fitodisponibilidade dos metais pesados decorrentes das baixas concentrações nas amostras de solo.