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1
Diggle, Rebecca. "Regulatory science and uncertainty in the risk assessment of pesticide residues." Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/11451/.
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In this thesis I examine how the scientific advisory system in England and Wales has responded to concerns about the risks of pesticide residues in food and demands for wider engagement in the formulation of advice. Specifically, I explore how the Advisory Committee on Pesticides (ACP) frames scientific uncertainties in risk assessment, and why some bodies outside and within government are critical of the ACP’s approach that is centred in the conventional single-chemical, high-dose-response paradigm of toxicology. Although some of these challenges date back to the early history of pesticide regulation in England and Wales, the emergence of scientific research employing different methods to assess the effects of chemical mixtures and chronic low-level exposure has stimulated new concerns about the risks posed by pesticide residues for human health. Using semi-structured interviews and documentary analysis, a key finding is that concerns about low-level exposure to chemical mixtures have been persistently bracketed in official advice as insufficient for changing current advice and regulation. Drawing from literature in science and technology studies, I account for this finding in three ways. First, it is perceived that change is unnecessary since established methods of pesticide risk assessment represent an exemplar for other domains. Secondly, evidence selection by the ACP and related committees is shaped by regulatory guidelines which aim to provide standardisation and quality assurance, but also constrain judgements about which risk assessment studies are considered admissible. Thirdly, fundamentally different notions are at play in terms of what constitutes legitimate expertise and who should embody it, leading to tensions within government as well as between the ACP and NGOs. These limit the impact of post-BSE attempts to make the role of scientific advice in policy-making more participatory and ‘evidence-based’, and the capacity to introduce new paradigms of chemical risk assessment in the pesticide advisory process.
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Trevisan, Marcos José. "Resíduos de carbosulfan e de seus metabólitos carbofuran e 3-hidroxi-carbofuran em frutos e folhas de laranjeira [Citrus sinensis (L.) Osbeck], determinados por cromatografia em fase gasosa." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-12022003-144017/.
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Este estudo teve como principal objetivo avaliar o inseticida/acaricida carbamato carbosulfan e seus metabólitos carbofuran e 3-hidroxi-carbofuran, de modo a estudar este metabolismo em condições de campo, abrangendo a sua ocorrência como resíduos em frutos, cascas e suco, bem como o potencial de contaminação do agroecossistema (resíduos em folhas). A degradação/persistência desses resíduos nos substratos foi monitorada durante certo período de tempo de tomada de amostras, e comparada com o limite máximo de resíduo (LMR) e o intervalo de segurança, estabelecidos pela legislação Brasileira para frutos. O trabalho consistiu de dois experimentos: o Experimento 1, realizado no município de Cordeirópolis-SP com o cultivar Valência, e o Experimento 2 com o cultivar Pêra Rio, em São Pedro-SP, ambos com 4 tratamentos (3 repetições), que foram os seguintes: A - uma única aplicação na dosagem X = 50 mL p. c./100 L de água (10 g i. a./ 100 L de água) de Marshal 200 SC (recomendada na bula); B - uma única aplicação na dosagem 2X = 100 mL p. c./100 L de água (20 g i. a./ 100 L de água) de Marshal 200 SC; C - quatro aplicações na dosagem X(4x) = 50 mL p. c./100 L de água (10 g i. a./ 100 L de água) de Marshal 200 SC; D - Testemunha. O método analítico consistiu na extração dos resíduos com acetato de etila, limpeza dos extratos em cromatografia de permeação em gel (GPC), e determinação quantitativa em cromatógrafo de gás equipado com detector de nitrogênio - fósforo (NPD). As amostras de frutos e de folhas foram colhidas um dia antes da aplicação parcelada (-1 dia), e aos zero, 1, 3, 7, 14, 21 e 28 dias após. No Experimento 2, os frutos foram separados em casca e suco, com o propósito de se estudar a ocorrência de seus resíduos nestes substratos, e, desse modo a possibilidade de penetração na polpa (suco). Os limites de quantificação (LOQs), determinados por estudos de fortificação e recuperação, foram iguais para ambos os substratos (0,05 mg.kg -1 , ppm) (fruto e folha) e para os três analitos (carbosulfan, carbofuran e 3-hidroxi-carbofuran). Em ambos os experimentos, o metabolismo do carbosulfan em carbofuran foi em geral rápido, tanto no fruto como na folha, e mais lento deste para 3-hidroxi-carbofuran, sendo os resíduos nas folhas sempre maiores do que nos frutos. Para o fruto, no Experimento 1, os valores do LMR e do período de carência mostraram-se de acordo com a legislação vigente, com resíduos totais de carbosulfan (carbosulfan + carbofuran + 3-hidroxi-carbofuran) abaixo do LMR (0,05 mg.kg -1 ) ao cabo do intervalo de segurança (7 dias). No Experimento 2 os resultados permitiram a determinação dos valores de ½ vida para carbofuran de 9,4 e 3,0 dias, respectivamente para casca e folha, para o tratamento A (dosagem recomendada). A análise do suco revelou níveis inferiores ao LOQ (< 0,05 mg.kg -1) em todas as amostras de qualquer tratamento.The objective of this study was to evaluate the insecticide/acaricide carbamate carbosulfan and its metabolites carbofuran and 3-hydroxy-carbofuran, in order to study the metabolism in field conditions, including its occurrence as residues in fruits, peel and juice, as well as the potential for agroecosysten contamination (residues in leaves). The degradation/persistence of these residues in/on these substrates was monitored through of time of sample collecting, and comparing with the Maximum Residue Level (MRL) and the safety interval, established by the Brazilian legislation. This research consisted of two experiments: Experiment 1 was carried out in Cordeirópolis - SP County, using Valência variety, and Experiment 2 with Pêra Rio variety, in São Pedro - SP County, both with four treatments (3 repetitions): A - only one application of dosage X = 50 mL c. p./100 L of water (10 g a. i./100 L of water) of Marshal 200 CS (recommended dosage); B - only one application of dosage 2X = 100 mL c. p./100 L of water (20 g a. i./100 L of water) of Marshal 200 CS; C - four applications of dosage X(4x) = 50 mL c. p./100 L of water (10 g a. i./100 L of water) of Marshal 200 CS; D - control. The analytical method consisted in a extraction of residues with ethyl acetate, clean-up of extracts in gel permeation chromatography (GPC), and quantitative determination in gas chromatography equipped with nitrogen and phosphorus detector (NPD). Fruit and leaf samples were collected one day before the treatment (-1 day) and zero, 1, 3, 7, 14, 21 and 28 days after the combined application. In Experiment 2, fruits were separated in peel and juice, with the purpose of studying the occurrence of residues in these substrates, and the possibility of their penetration in the pulp (juice). The limits of quantification (LOQs) determinated by studies of fortification and recovery, were equal to both substrates (0,05 mg.kg -1, ppm) (fruit and leaf) and to the three analyts (carbosulfan, carbofuran and 3-hydroxy-carbofuran). In both experiments, the metabolism of carbosulfan to carbofuran was in general quick, in fruit as well in leaf, and slower to 3-hydroxy-carbofuran, being the residues in leaves always higher than in fruits. In Experiment 1, MRL and safety interval values were according to the legislation, with carbosulfan total residues (carbosulfan + carbofuran + 3-hydroxy-carbofuran) lower than the MRL (0,05 mg.kg -1 ) at the end of the safety interval (7 days). In Experiment 2, the results showed carbofuran half-lives values of 9,4 and 3,0 days, respectively to peel and leaf, to the treatment A (recommended dosage). The analysis of juice showed levels below LOQ (< 0,05 mg.kg -1 ) in all samples and treatments.
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Cerri, Fabiana. "Validação de metodologia para análise de procimidona em morango e determinação de seus resíduos na fruta \"in natura\" e produtos processados." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/11/11141/tde-15122008-145419/.
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O morango utilizado pela indústria alimentícia tem seu sabor e aroma bastante valorizados e apreciados, quando comparado com outras frutas. Entretanto, é um produto muito delicado e altamente perecível, exigindo, assim, o uso de técnicas adequadas de colheita e pós-colheita. Para manter sua qualidade e quantidade de produção, observa-se um aumento do uso de agrotóxicos para minimizar prejuízos causados por pragas e doenças do campo. Porém, os pesticidas podem deixar resíduos persistentes nos alimentos e o seu consumo in natura ou industrializado pode ficar comprometido, colocando em risco a saúde do consumidor. Assim, este trabalho teve por objetivo estudar a influência do processamento de morangos, como, minimamente processado, geléia e polpa frente aos resíduos do fungicida procimidona. Em experimento de campo foi aplicado o produto Sumilex 500 WP nos seguintes tratamentos: A testemunha (sem aplicação); B uma única aplicação de 300 g p.c. 100 L-1 água (150 g i.a. 100 L-1 água) e C 3 aplicações sucessivas de 300 g p.c. 100 L-1 água (150 g i.a. 100 L-1 água), com intervalos de 7 dias entre elas. As amostragens foram iniciadas no dia anterior a aplicação do tratamento B (-1 dia) e aos 0, 1, 3, 5, 10 e 15 dias, sendo amostrados frutos in natura, para posterior processamento, como minimamente processado, geléia e polpa. O método de análise consistiu na extração dos resíduos de procimidona com acetato de etila, limpeza do extrato (clean up) feita por cromatografia de exclusão por tamanho molecular de alta eficiência - GPC e determinação quantitativa feita por técnica de cromatografia em fase gasosa acoplado a detector de captura de elétrons - CG/ECD. O método analítico apresentou recuperação em torno de 85,5% com desvio padrão de 7% e limites de quantificação de 0,00076 mg.kg-1 e detecção de 0,00023 mg.kg-1. Os valores de procimidona encontrados em morango não excederam o LMR (3 mg.kg-1) estabelecido pela legislação brasileira, em qualquer um dos períodos de coleta das amostras. Nos tratamentos que receberam aplicações no campo (B e C) os níveis de procimidona decresceram no decorrer do tempo, tanto para o morango in natura como para os produtos processados de morango. Os valores de meia vida de degradação foram de 7-8 dias para ambos os tratamentos. Não houve redução significativa nos níveis de resíduos encontrados no morango in natura, assim como para os obtidos na polpa e minimamente processado. Porém, uma considerável degradação de procimidona foi observada no processo de cozimento, apresentado pela baixa concentração de resíduos na geléia. De maneira geral, a procimidona apresentou maiores níveis no morango in natura e menores na geléia de morango (produto final).The strawberry used by the food industry has flavor and aroma very valued and appreciated when compared to the other fruits. However, it is a very delicate and highly perishable product, demanding, therefore, the use of appropriate techniques of harvesting and post-harvest. To keep quality and quantity of production, there is an increase of pesticides utilization in order to minimize damages caused by pests and field diseases on the field. However, the pesticides can leave persistent residues in the foods and their consumer fresh or industrialized may be impaired, putting the consumer health at risk. Thus, this work aimed to investigate the influence of the strawberries processing, as, minimally process, jam and pulp front of the waste of fungicide procymidone. In the field experiment, was applied the Sumilex 500 WP product according the treatments: A control (without application); B - a single application for 300 g c.p. 100 L-1 water (150 g a.i. 100 L-1 water) and C - 3 successive applications for 300 g c.p. 100 L-1 water (150 g a.i. 100 L-1 water), with intervals of 7 days between them. The sampling started in the previous day of the last treatment application B (- 1 day). Other sampling were carried through 0, 1, 3, 5, 10 and 15 days, and sampled fresh fruit, for further processing, such as minimally process, jam and pulp. The analysis method consisted in extraction with ethyl acetate, cleaning of the extract by gel permeation chromatography (GPC) and quantitative determination by gas chromatograph with specific detector of electron capture (GC/ECD). The analytical method presented recovery around 85,5% with errors of 7% and the quantification limits of 0,000076 mg.kg-1 and detection limits of 0,00023 mg.kg-1. The procymidone values found in strawberry did not exceed the maximum residues limits (3 mg.kg-1) fixed by brazilian legislation, in any periods of harvest. In the treatments that received application on the field (B and C) the procymidone levels decreased in the course of the study, as fresh strawberry as for process product of strawberry. The half-life values of degradation were of 7-8 days to the both treatments. There was no significant reduction in the residue levels found in strawberry fresh, pulp and minimally process. But, a considerable degradation of procymidone was observed in the cooking process, showing by low residues concentrations in the jam. Overall, the procymidone showed higher residues in fresh strawberry and lower on strawberry jam (final product).
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Amajuoyi, Ifeanyi Kingsley. "Behavior and elimination of pesticide residues during supercritical carbon dioxide extraction of essential oils of spice plants and analysis of pesticides in high-lipid-content plant extracts." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963029177.
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Ahmad, Maqbool. "Pesticide residue analysis using supercritical fluid extraction." Thesis, University of South Wales, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320724.
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Haag, Jennie, and Anna Landahl. "Pesticide residues in cucumbers cultivated in Bangladesh." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-234741.
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Pesticides are widely used for preventing crop losses due to pest attack. In Bangladesh, the food safety and health of farmers are being compromised as a result of poor regulation concerning usage of pesticides in food production. The aim of this study was to identify and quantify pesticides applied on cucumber crops in Bangladesh. A method for extraction and clean-up was developed to allow the quantification of four pesticides by GC-ECD in vegetable samples, specifically cucumber. The accuracy of the method was validated using recovery and its precision by studying the standard deviation and relative standard deviation. Analysis of cucumber samples obtained in the field showed no traces of the target pesticides. The results indicate that different types of chemicals are used on the examined crops. It is also believed that the growth habit of cucumber may affect the exposure to pesticides. To overcome the health hazards, restrictions regarding the types and quantities of chemicals used on the fields need to be implemented. Further studies would benefit from being executed in a controlled environment, and monitoring of which substances that are applied at which amounts.
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Seeger, Bettina [Verfasser]. "Risk assessment of hormonally active pesticide residue mixtures / Bettina Seeger." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2016. http://d-nb.info/1107039568/34.
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Wei, Jin Chao. "Research on novel sample preparation and analytical methods for trace determination of the pesticides in traditional Chinese medicine." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3953269.
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Trevizan, Luiz Roberto Pimentel. "Resíduos de acefato, de seu metobólito metamidofós e de clorotalonil em cultura protegida de tomate (Lycopersicon esculentum Mill) e de campo." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-18032003-165159/.
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O desenvolvimento da agricultura, a modernização dos meios da produção agrícola, buscando atender um mercado exigente em produtos de alta qualidade tem aumentado grandemente os cultivos conduzidos em condições de estufa. Tais culturas, demandam o uso de pesticidas para controle de problemas fitossanitários, cujos resíduos, principalmente em hortaliças e frutas, são motivo de preocupação com a saúde de consumidores e de operários que necessitam trabalhar nessas instalações. Os objetivos deste estudo foram determinar resíduos dos inseticidas acefato, de seu metabólito metamidofós e do fungicida clorotalonil em um sistema de cultura de tomate de estufa, em comparação com cultura de campo, de modo a abranger: estudo do metabolismo de acefato a metamidofós; alteração da contaminação dos resíduos de acefato, metamidofós e de clorotalonil em alguns compartimentos do sistema protegido (fruto, folha e solo); e comparação entre os níveis residuais encontrados nos frutos de cultura de estufa com os limites máximos de resíduos (LMRs) e os intervalos de segurança estabelecidos pela legislação brasileira. Foram conduzidos um experimento de estufa (Piracicaba-SP) e outro de campo (Pereiras-SP), no período de maio-agosto/2002 (outono-inverno), em tudo, muito semelhantes um ao outro. Os tratamentos aplicados foram: a: testemunha; b: uma aplicação de 100 g de Orthene 750 BR (75 g i.a. acefato) + 400 mL de Dacostar 500 (200 g i.a. clorotalonil).100 L -1 de água; c: uma aplicação com o dobro das dosagens dos pesticidas do tratamento b; d: quatro aplicações na dosagem do tratamento b. As amostras foram tomadas nos dias -1, zero, 1, 3, 7, 14 e 21 dias após a última ou única aplicação. O método analítico constou da extração dos resíduos com acetato de etila, limpeza dos extratos por técnica de cromatografia de permeação em gel (GPC), com eluição procedida com uma mistura acetato de etila/ciclohexano. A determinação quantitativa foi feita por técnica de cromatografia em fase gasosa, usando-se detector fotométrico de chama (PFPD) para os resíduos de acefato e de metamidofós e detector de captura de elétrons (µ-ECD, Ni 63 ) para os de clorotalonil. Os limites de quantificação do método (LOQs) para os três pesticidas, em fruto e solo foi de 0,05 mg.kg -1 (ppm); em folhas foi de 0,5 mg.kg -1 (ppm). Foram realizadas 1.512 análises dos três analitos, sendo 252 amostras de cada um dos experimentos. Os resultados indicaram que os resíduos de acefato, metamidofós e de clorotalonil, nos frutos de estufa e de campo, sempre estiveram abaixo dos respectivos LMRs em todo o período de colheita das amostras, inclusive no intervalo de segurança. Mostraram também, que o metabolismo de acefato a metamidofós foi muito baixo nos frutos, particularmente importante nas folhas, mas não bem caracterizado no solo. Ainda, foi observado que os resíduos de acefato e de clorotalonil foram invariavelmente maiores na estufa do que no campo, especialmente em folhas e no solo, sendo, também, estáveis e persistentes, em geral até a amostragem de 7 dias. Particularmente os resíduos de clorotalonil foram os mais persistentes, sendo encontrados nas amostras de 28 dias em níveis significantes, especialmente no solo.The development of agriculture, the modernization of means of agricultural production, the attempt to supply a demanding market for high quality produce has largely increased the crops carried out in greenhouse environment. Such crops demand the use of pesticides for the control the pest problems, which residues, mainly in fruit and vegetables, are reasons for worries about the health of consumers and workers that need to work in these installations. The objective of this study was to determine residues of the insecticide acephate, of its metabolite methamidophos and the fungicide chlorotalonil in a system of greenhouse tomato crop, in comparison to field crop, as to embrace: study of the metabolism of acephate to methamidophos; alteration of the contamination of residues of acephate, methamidophos and chlorotalonil in some compartments of the protected system (fruit, leaf and soil); and comparison between the residual levels found in the fruit of greenhouse crop with the maximum residue levels (MRLs) and the safety intervals stablished by the Brazilian legislation. It was carried out a greenhouse experiment (Piracicaba-SP) and another in field conditions (Pereiras-SP), in the period of May-August/2002 (Autumn-Winter), on a whole very similar to each other. The treatments applied were: a: check; b: an application of 100 g of Orthene 750 BR (75 g a.i. acephate) + 400 mL of Dacostar 500 (200 g a.i. chlorotalonil).100 L -1 of water; c: an application with the double dosage of the pesticides applied as treatment b; d: four applications with the dosage of the pesticides applied as treatment b. The samples were taken on the days -1, zero, 1, 3, 7, 14, 21 days after the last or only application. The analytical method included the residue extraction with ethyl acetate, clean-up of the extracts by gel permeation chromatography technique (GPC), with elution proceeded with a mixture of ethyl acetate/cyclohexane. The quantitative determination was done by gas chromatography technique, using flame photometric detector (PFPD) for the residues of acephate and of methamidophos, and electron capture detector (m-ECD, Ni 63 ) for the chlorotalonil. The limits of quantitation (LOQs) for the three pesticides, in fruit and soil was 0.05 mg.kg -1 (ppm); and in leaves 0.5 mg.kg -1 (ppm). There were performed 1512 analyses of the three analytis, being 252 samples from each one of the experiments. The results indicated that the residues of acephate, methamidophos and chlorotalonil, in greenhouse and field fruits, have always been below of their respective MRL's in the whole sample collecting period, including the safety intervals. It has shown as well, that the metabolism of acephate to metamidophos was much below in fruit, specially important in leaves, but not well characterized in the soil. It was still observed that the residues of acephate and chlorotalonil were invariable bigger in the greenhouse than in the field, specially in leaves as well as in soil, being also stable and persistent, in general, specially up to 7 day samples. Particularly, the residues of chlorotalonil were the most persistent, being found in the samples of 28 days in significant levels, specially in the soil.
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Gershater, Markus Christian. "Plant carboxylesterases involved in pesticide hydrolysis." Thesis, Durham University, 2006. http://etheses.dur.ac.uk/2934/.
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Many herbicides are applied in the form of carboxylic esters to increase their hydrophobicity and hence aid their passage through the waxy cuticle. Hydrolysis in planta of these pro-herbicide esters releases the active acid or alcohol and the rate of this cleavage can be a factor in determining herbicide selectivity. Protein extracts from 13 crop and weed species were assayed for carboxylesterase activity toward multiple xenobiotic and pesticide ester substrates, including 2,4-D-methyl, aryloxyphenoxypropionate esters and p-nitrophenyl esters. A diversity of activities was exhibited by the different species, with Arabidopsis thaliana extracts showing high hydrolytic activity toward several xenobiotic esters, particularly 2,4-D- methyl.The major 2,4-D-methyl hydrolysing enzyme in arabidopsis cell cultures was purified through three rounds of chromatography, then selectively labelled with a biotinylated fluorophosphonate probe (FP-biotin). Following streptavidin affinity purification, the labelled protein was identified by proteomics as the previously uncharacterised serine hydrolase AtCXE12. Recombinant AtCXE12 was subsequently confirmed to effectively hydrolyse 2,4-D-methyl.A T-DNA insertion knockout line that did not express AtCXE12 was identified and characterised. Protein from the knockout plants did not contain AtCXE12 and was found to have a reduced rate of 2,4-D-methyl hydrolysis compared to wild-type plant extracts. This translated into a higher tolerance of 2,4-D-methyl in young atcxel2 plants, due to a lower rate of bioactivation of the pro-herbicide.The fluorophosphonate-based chemical probe was subsequently used to identify other major serine hydrolases in arabidopsis. AtCXE12 and three previously uncharacterised hydrolases were identified, each belonging to a distinct enzyme family.
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Al-Saad, Jalal Abdulla. "Development of novel solid phase extraction materials for pesticide residue analysis." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263469.
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Monteiro, Sérgio Henrique. "Desenvolvimento e validação de metodologia para determinação de resíduos de pesticidas piretróides por HPLC em feijão." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-22062016-160326/.
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Um método rápido utilizando cromatografia liquida (LC) foi desenvolvido para determinação simultânea de 7 pesticidas piretróides (bifentrina, cipermetrina, fenpropatrina, fenvalerato, permetrina, lambda-cialotrina, e deltametrina). Os resíduos são extraídos com acetona e a partição realizada de acordo com o método multi-resíduos DFG-S19, substituindo diclorometano por acetato de etila/ciclohexano (1+1) e purificação usando cromatografia de permeação a gel com uma coluna Biobeads SX3 e acetato de etila/ciclohexano (1+1) como eluente. A separação por LC é realizada com uma coluna LiChrospher 100 RP-18 e acetonitrila/água (8+2) como fase móvel. Os pesticidas são detectados em 212nm. As recuperações dos 7 pesticidas piretróides em amostras de feijão fortificadas em 0,010; 0,100; e 1,000 mg/kg ficaram entre 71-105%. A diferença particular deste método é o limite de quantificação, os quais ficaram entre 0,004-0,011 mg/kg, abaixo de muitos outros métodos de LC descritos na literatura. A cromatografia a gás (GC) com detector de captura de elétrons é mais sensível que a LC, mas o método com LC facilita a identificação dos picos. A GC apresenta muitos picos enquanto a LC apresenta apenas um para a maioria dos piretróides. A análise com LC é uma boa alternativa para a determinação de resíduos de piretróides em feijão. Durante o ano de 2005, um total de 48 amostras de feijão comercializadas na cidade de São Paulo, foram analisadas. Nenhum resíduo de pesticida piretróide foi detectado nas amostras.A rapid liquid chromatographic (LC) method has been developed for simultaneous determination of 7 pyrethroid insecticides (bifenthrin, cypermethrin, fenpropathrin, fenvalerate, permethrin, lambda-cyhalothrin and deltamethrin) in beans. Residues are extracted from beans with acetone and the partition realized according to the multi-residue method DFG-S19, replacing dichloromethane by ethyl acetate/cyclohexane (1+1) and cleaned up using gel-permeation with a Biobeads SX3 column and ethyl acetate/cyclohexane (1+1) as eluant. LC separation is performed on a LiChrospher 100 RP-18 column with acetonitrile/water (8+2) as mobile phase. The pesticides are detected at 212 nm. Recoveries of 7 pyrethroid insecticides from beans fortified at 0.010; 0.100; 1.000 mg/kg levels were 71-105 %. The particular differential of this method is the quantification limits, which were between 0.004-0.011 mg/kg, lower than most of the limits reported for LC methods described in the literature. The gas chromatographic (GC) with electron capture detection is more sensitive than LC, but the LC method facilitates the identification of the peaks. Analysis of pyrethroids by GC shows several peaks, but LC shows only one for most pyrethroids. The analysis by LC was a good alternative for determination pyrethroid residues in beans. During 2005 year, a total of 48 bean samples commercialized in Sao Paulo City were analyzed. No residues of pyrethroids pesticides were detected in the samples.
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Marella, Venkata S. S. R. "Understanding plant residue decomposition in shrubland ecosystem." Thesis, Bangor University, 2015. https://research.bangor.ac.uk/portal/en/theses/understanding-plant-residue-decomposition-in-shrubland-ecosystem(6dcfe4c8-c9a4-46fe-aeb7-58b0a6e0fbf0).html.
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Litter decomposition is a key component in ecosystem C and nutrient cycling. Shrubland litter decomposition is not well understood, even though shrublands cover a significant proportion of earth surface. This project aims to investigate the decomposition of shrubland plant residue (Cistus monspeliensis L.). The first and second experimental chapters of this thesis present the data about root chemistry, C and N mineralisation from the decomposing roots. Root tissue chemistry varies significantly with age, younger roots consist of higher relative amounts of N, P, K, soluble compounds, conversely Ca, hemicellulose, cellulose concentrations are higher in older roots. Faster short-term C, and N mineralisation rates were observed in senescing younger roots compared to the older roots under our experimental conditions. The third experimental chapter is about leaf litter decomposition study using litter bag technique. Accumulated mass loss from the decomposing leaf litter is a biphasic process where initial rapid mass loss followed by relatively slower phase. Among the various leaf litter decomposition parameters lignin: N best explained the accumulated mass loss. Fourth experimental chapter is an attempt to understand the 14C mineralisation process from decomposing soluble and insoluble components of above and below ground plant parts. Soluble components have shown faster 14C mineralisation compared to the insoluble fractions of above (stem and leaf) and belowground (roots) plant components. Belowground plant components have shown a distinctive 14C mineralisation pattern with more % 14C entering in to microbial biomass pool compared to the aboveground components which will have consequences on whole ecosystem C cycle. Results from final experimental chapter indicate that C sourced by hyphal biomass reside longer duration even after death thereby contribute significant amounts of C to the belowground. However, further long-term studies that includes multi plant species under filed conditions are needed before these results extrapolate to the shrubland ecosystem.
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au, j. anderson@murdoch edu, and Jonathan Anderson. "Impacts of Amending Bauxite Residue Sands with Residue Fines for the Establishment of Vegetation on Residue Disposal Areas." Murdoch University, 2009. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20090831.155453.
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Long term storage of bauxite residue materials requires a capping stratum which will limit erosion while stabilizing slopes, limit deep infiltration of water into storage piles, and be aesthetically acceptable to the surrounding community. A diverse native vegetative community capable of surviving seasonal drought, low plant available water and nutrient constraints has the best potential of satisfying most, if not all of these requirements. Current and past rehabilitation of residue disposal areas (RDAs) using species native to southwest Western Australia has exhibited varying success. Current practices at Alcoa World Alumina Australias (Alcoa) Western Australia refineries have bauxite residue fines (< 150 ìm) stored within impoundments, in which the outer embankments are constructed with bauxite residue sands (> 150 ìm). The residue sands are also used as the growth media in the capping stratum for vegetation establishment on the disposal sites. Despite the inherently hostile properties of residue sand (pH > 10, EC(1:5) > 4 dS m-1, and ESP > 50), reductions in alkalinity (pH), salinity (EC) and sodicity (ESP) are corrected, through freshwater leaching, to a greater extent than is possible with residue fines. Although leaching can reduce the hostile character of residue sand, additions of phosphogypsum are typically added to expedite the removal of Na and alkalinity, and inorganic fertilizers are incorporated to improve the nutrient status of the growth media. However, due to the inconsistencies in vegetation establishment, which are attributed to poor water retention, inherent nutrient deficiencies and rapid loss of nutrients within residue sands (because of high hydraulic conductivity), further amendments are required.
The aim of this study was to determine if amending the residue sand capping layer with residue fines would enhance its overall growth potential for vegetation establishment. Additions of fines to residue sands were predicted to increase water retention, add nutrients and increase the ability of the growth media to retain nutrients. Comparisons were made between the treated residue fines (seawater washed, carbonated, or unaltered) at a series of fines additions (1 - 20 % w/w) and a control(residue sand) amended with 2% (w/w) phosphogypsum and inorganic fertilizer.
Comparisons were to determine the differences in 1) water retention, 2) nutrient concentrations and nutrient retention, and 3) plant growth responses and plant biomass nutrient concentrations between the growth media treatments. Four experiments were set up to measure differences in these variables which included: a glasshouse study involving the growth of Acacia saligna; a germination and emergence study (A.saligna); a two year field study in Western Australia; and a glasshouse column leaching study.
Water retention increased with increasing percentage of residue fines addition. Plant available water (PAW) increased up to 110 %, with a 20 % increase in fines, representing an increase of 0.026 m3 PAW m-3 residue growth media, when compared to the residue sand only. This increase in PAW was attributed to changes in pore space distributions, due to the increasing fines contents altering the sandy texture to loamy sand texture class. However, initially much of this increase in PAW may not be realized, due to estimated temporary increases in osmotic potential associated with the high salt contents of residue sand and fines. Fines materials have much greater salt contents, and thus need to be leached to a greater extent than sands to remove the associated osmotic potential effects.
Essential plant nutrients (P, K, S, Ca, Mg, and B) were increased with additions of residue fines in the glasshouse studies, although many nutrients (Mg, Zn, Mn and B) were still marginal for sustainable plant growth and development. Seawater treated residue fines additions produced the greatest increases in growth media nutrients with substantial increases in soluble (> 7 mg L-1) and exchangeable (> 0.10 cmolc kg-1) Mg, being up to 400 % greater than all other treatments. Along with these necessary nutrients, concentrations of Na were also increased in all fines additions treatments. Added Na may offset the benefits of fines additions, at least in the short term, due to inhibitions of cation uptake from Na competition. However, in the column leaching study soluble and exchangeable Na was lost rapidly from the profile, due to Ca and K displacement of Na from exchange sites during leaching. Soluble Na was removed from the profile to < 5 % of initial concentrations, after only three pore volumes of leaching, and exchangeable Na was removed from charge sites to less than 25 % of the initial concentration. Fines additions did increase concentrations of Mg and K on exchange sites, thus reflecting increased nutrient retention capacity relative to that in residue sand only.
Plant growth responses and plant biomass nutrient concentrations were altered with the additions of residue fines to residue sands. The germination and emergence study demonstrated that the emergence of native seedlings was affected by additions of fines, due to the increased salinity and sodicity of the materials. Acacia saligna seedling emergence was inhibited by EC(1:5) > 2 dS m-1, which was highly correlated with a Na/Ca ratio of > 40, for all treatments, except the seawater fines additions. Seeds sown in seawater treatments emerged from growth media with EC(1:5) as high as 3.33 dS m-1 and appeared to be better correlated with Ca/Mg ratios than any other variable. Native vegetation growth responses showed mixed results in fines treated residues in the field. In the greenhouse study, plant growth tended to decrease with fines additions. Poor plant growth with increasing fines additions occurred despite the increased water retention and increased nutrients. This was attributed to the addition of Na associated with the residue fines, as increases in Na, EC and ESP in fines treatments all appear to have limited growth of Acacia saligna in the glasshouse over three months. Seawater fines additions had elevated Mg and B concentrations in plant biomass, and performed better than the carbonated or unaltered fines treatments, but still had reduced growth compared to the residue sand, which contained lower Na concentrations. Additional plant growth limitations may have occurred, due to possible plant nutrient deficiencies including: Mg, Zn, Mn and B and Na toxicity.
Incorporation of residue fines into residue sands did increase water retention, nutrient concentrations and the nutrient retention capacity, but did not enhance the overall growth potential for vegetation, at least in the short term. Reductions in germination and emergence of seedlings and reduced plant growth were attributed to increases in Na concentrations introduced from the fines. Seawater washed residue fines had lower ESP and greater concentrations of nutrients, thus reducing the negative impacts from the additional Na introduced, and showed the greatest promise as a fines amendment. As leaching occurs over the first few initial months of rehabilitation, it is expected that the majority of the Na will be removed, from a system with an addition of 5 to 10 % fines, and the positive benefits of the fines additions will than be realized. Findings also illustrate that delaying the planting of vegetation on RDAs, until adequate leaching has occurred to reduce the Na concentrations, will substantially increase vegetation emergence and establishment.
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Yau, Kerrm Y. F. "Synthesis of recombinant antibody fragments for pesticide residue analysis using enzyme-linked immunosorbent assays." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ35947.pdf.
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Motsoeneng, Marnonyowe Portia. "Relationship between pesticide residue levels and neurotoxicity among women on farms in the Western Cape." Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/13344.
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Includes bibliographical references.Farm workers and residents living in and around farms are exposed to pesticides. Women are vulnerable to health risks posed by pesticides. To date there are few studies that have investigated the relationship between pesticide residues in human body fluids and neurotoxicity. This study therefore aims to investigate the relationship between urinary pesticide residue levels and neurotoxicity amongst women working in farms in the Western Cape, South Africa.
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Vilca, Franz Zirena. "Validação de método de análises multiresíduo para determinação de pesticidas em morango (Fragaria ananassa Duch) e quinoa (Chenopodium quinoa Willd), por técnicas cromatográficas CG-μECD e LC-MS/MS." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/91/91131/tde-30102012-163305/.
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O método de extração QuEChERS, foi ajustado, validado e utilizado para a determinação de doze agrotóxicos organoclorados em 37 amostras de quinoa provenientes da colheita 2010-2011 de Puno - Peru e 36 amostras de morango provenientes de três varejões da cidade de Piracicaba do Estado de São Paulo - Brasil coletadas durante o período de outubro de 2010 até setembro de 2011, usouse um sistema cromatográfico a gás acoplado a um detector de captura de elétrons μECD. Por outro lado para a determinação de 36 agrotóxicos nas amostras morango e 42 agrotóxicos em quinoa, o QuEChERS foi ajustado e validado para seu uso com um sistema cromatográfico líquido acoplado a espectrometria de massas LCMS/ MS; para o processo de validação usou-se amostras de quinoa e morango sem resíduos de agrotóxicos, os quais foram usados como branco de matriz. Os métodos mostraram linearidade de r2 >= 0,99; LQs na ordem de 0,001 mg kg-1, foram realizados testes de recuperações considerando os LQs e dez vezes estes, sendo que as recuperações foram entre 70% e 120% na maioria das concentrações. Com o intuito de avaliar o efeito do tamanho de partículas de quinoa no processo de validação do método QuEChERS para a determinação de sete agrotóxicos com uso de CG-μECD, foram realizados três tipos de moagem usando processador de alimentos e um sistema de moagem criogênico, observou-se uma maior uniformidade das partículas e um incremento do efeito matriz nas amostras tratadas com sistema criogênico. Das 37 amostras de quinoa analisada uma amostra (Cabanillas) proveniente do sistema de produção orgânico (Salcedo INIA) mostrou contaminação por quatro agrotóxicos (OP DDE com 0,015 mg kg-1, PP DDE 0,032 mg kg-1, PP DDD 0,089 mg kg-1 e endosulfan sulfato com 0,034 mg kg-1) e das 36 amostras de morango seis apresentam contaminação por endosulfan sulfato nas concentrações de 0,003 a 0,020 mg kg-1 e uma amostra coletada no dia 15/04/2011 apresentou 0,011 mg kg-1 de procloraz, compostos que não são permitidos para serem usados em morango. Conclui-se que o método QuEChERS usado com o sistema CG-μECD e LC-MS/MS é uma alternativa viável para a determinação de agrotóxicos em morango e quinoa.The QuEChERS extraction method has been adjusted, validated and used for determination of twelve organochlorine pesticides on 37 quinoa samples from the harvested 2010-2011 from Puno - Perú and 36 strawberries samples from three markets from Piracicaba city in Sao Paulo State-Brazil collected during the period from October of 2010 to September of 2011, were used a gas chromatographic system coupled to an electron capture detector μECD. On the other hand, for the determination of 36 pesticides in strawberries samples and 42 quinoa samples, The QuEChERS method was adjusted and validated for use with a liquid chromatographic system coupled to mass spectrometer LC-MS/MS; for the validation process a quinoa and strawberries samples without pesticides residues, which were used as a blank. The methods were linear r2 >= 0.99; LQs in the order of 0.001 mg kg- 1, were carried out recoveries considering the LQs and ten times these, and the recoveries were between 70% and 120% in most of the concentrations. In order to evaluated the effect of the particle size of the quinoa on the validation process of the QuEChERS method for determination of seven pesticides using GC-μECD, were performed three types of milling using a food processor and cryogenic grinding, there were a greater uniformity of the particles and increase of the matrix effect in the samples treated with cryogenic system. From the 37 quinoa samples analyzed one sample (Cabanillas) coming from organic system production (Salcedo INIA) showed contamination by four pesticides (OP DDE with 0.015 mg kg-1; PP DDE 0.032 mg kg- 1; PP-DDD 0.089 mg kg-1 and endosulfan sulfate with 0.034 mg kg-1) and from the 36 strawberries samples six showed contamination by endosulfan sulfate in the concentrations of 0.003 to 0.020 mg kg-1 and one sample collected 15/04/2011 showed 0.011 mg kg-1 of prochloraz, compounds that are not permitted to be used in strawberries. We concluded that the QuEChERS method used with a system of GC- μECD and LC-MS/MS is a viable alternative to determinate pesticides in strawberries and quinoa.
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Marcomini, Angelina Maria. "Bioatividade e efeito residual de nanoformulações de nim sobre Spodoptera frugiperda (J.E. Smith)." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-09112009-141755/.
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Na tentativa de reduzir a biodegradação dos compostos ativos do nim e melhorar seu efeito residual, extratos de nim foram nanoformulados com diferentes tipos de nanoparticulas e de polímeros. Estas nanoformulações foram testadas sobre Spodoptera frugiperda (J. E. Smith) e sua eficiência comparada a um produto comercial. Os polímeros poli--caprolactona (PCL), poli-- hidroxibutirato (PHB) e polimetilmetacrilato(PMMA), foram utilizados nas quantidades 0,25, 0,50 e 0,75g, e em dois tipos de nanopartículas (cápsulas e esferas). Foram utilizados Tween®80 e polivinil álcool (PVA) como agentes tensoativos. As nanoformulações foram produzidas em suspensão aquosa e em pó, sendo diluídas para aplicação. Essas nanoformulações foram aplicadas sobre dieta artificial oferecida a lagartas de segundo instar de S. frugiperda, e em plantas de milho das quais as folhas foram cortadas e fornecidas a lagartas de primeiro instar. A eficiência de diferentes nanoformulações foi testada considerando a mortalidade e o peso 10 dias após o tratamento. Quando aplicado em dieta artificial foi observada redução no peso larval. Entretanto, quando aplicadas em folhas de milho, quatro nanoformulações causaram mortalidade entre 40 a 46%. Essas quatro nanoformulações foram avaliadas quanto à preferência alimentar e efeito residual. Foram conduzidos três bioensaios, nos quais as folhas de milho tratadas com as quatro nanoformulações foram oferecidas às lagartas aos 1, 3 e 7 dias após a pulverização (DAP), considerando-se mortalidade e peso das lagartas após 10 dias. Simultaneamente, foram realizados testes de preferência alimentar com dupla escolha (tratamento x controle) com discos foliares de milho aos 1, 3 e 7 DAP. A preferência alimentar foi determinada por meio de um índice de preferência, calculando-se a área foliar consumida pela lagarta após 24h. O efeito residual das nanoformulações foi menor que do produto comercial avaliado. Apenas uma nanoformulaçao e Organic Neem® apresentaram fagodeterrência a S. frugiperda, mas somente em 1 DAP. Embora as nanoformulações tenham causado mortalidade e redução de peso larval, sua eficiência foi inferior a do produto comercial.Neem extracts were nanoformulated with several types of nanoparticles and polymers in a tentative to reduce the biodegradation of neem active compounds and improve their residual effect. These nanoformulations were tested against Spodoptera frugiperda and their efficacy compared to a commercial product. The polymers poly(-caprolactone) (PCL), poly(- hidroxibutirate) (PHB) and poly(methyl methacrylate) (PMMA) were used in the quantities 0.25, 0.50 and 0.75g and two sorts of nanoparticles (capsules and spheres). Tween®80 and poly(vinyl alcohol) (PVA) were utilized as surfactants. The nanoformulations were produced as aqueous suspension and powder and further diluted before application. These nanoformulations were sprayed on artificial diet offered to second instars of S. frugiperda, and on corn plants which had their leaves offered to first instars. The efficacy of the different formulations was tested by assessing larval mortality and weight 10 days after treatment. When applied to artificial diets, reduced larval weight was observed, but four of them caused 40 to 46% mortality when applied on corn plants. The four most effective nanoformulations were further tested to evaluate their effects on S. frugiperda larval feeding preference and their residual effect. Three bioassays were set up using corn leaves treated with these, wich were offered to larvae at days 1, 3 and 7 after spraying (DAS), having the larval mortality and weight assessed 10 days after larval exposure. Simultaneously, choice tests for larval feeding preference (treatment x control) were carried out using corn leaf discs 1, 3 and 7 DAS. Feeding preference was evaluated by using a preference index calculated after the assessment of the leaf area fed by the larva 24h after exposure. The residual effect of the neem nanoformulations was lower than the commercial product evaluated. Only one nanoformulation and Organic Neem® were feeding deterrents to S. frugiperda, but only in the first day after the treatment. Although the nanoformulations caused larval mortality and weight reduction, their efficacy was not any better than that of the commercial product tested.
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Gibbs, Paul A. "The influence of residue chemical composition on gross rates of nitrogen mineralisation." Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388468.
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White, Paul Mark Jr. "Enhancing soil carbon sequestration with plant residue quality and soil management." Diss., Manhattan, Kan. : Kansas State University, 2006. http://hdl.handle.net/2097/222.
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Collins, Shane. "Residue composition influences nutrient release from crop residues." University of Western Australia. School of Earth and Geographical Sciences, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0171.
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[Truncated abstract] A greater adoption of stubble retention, minimum-till and no-till farming practices for the purposes of conserving soil, water and fertility requires a greater understanding of the complexity of physical and chemical interactions between the soil and crop residues. There is currently insufficient knowledge to allow reliable predictions of the effects of different residue types in different environments on soil fertility and crop growth, owing to the many residue characteristics and environmental interactions that have been shown to affect decomposition or nutrient release. The role of fibre and nutrient composition in nutrient release from crop residues, and implications for residue management techniques, were studied. Canola, lupin and field pea residues, obtained from farmland in Meckering and Northam, Western Australia, were separated into upper and basal stems, leaves, and siliques or pods. This was done to provide materials with a wide range of chemical and physical characteristics, and also allowed consideration of differential residue management of plant organs, such as comparing harvested canola siliques and retained canola stubble. Pre-treatment by chopping and/or humidification was applied to residues to provide some information about the processes of nutrient release. Residues were subjected to simulated rainfall to assess nutrient leaching from plant material, and placed on soil in pots in constant-temperature glasshouse conditions to assess decomposition. Amounts and rates of change of residue fibre and nutrients were determined throughout leaching and decomposition. Energy Dispersive X-ray (EDX) microanalysis was used to assess the location of diffusible ions in air-dried residues and the effects of humidification on nutrient positioning and release. ... However, the release of calcium and magnesium depended on the decomposition of the more recalcitrant components such as cellulose and lignin, as supported by microscopy results showing changes in nutrient distribution following humidification. The proportionality of amounts of calcium and magnesium leached and released during decomposition is likely to suggest a similarity of chemical form more than similarity of function or position of the two elements. Management of crop residues for maximising and optimising the timing of release of different nutrients will need to take into account the placement of different plant types and parts, particle sizes distribution and pre-treatment of material to efficiently manage short- and long-term soil fertility to sustain crops, particularly on degraded soils. Significant nutrient release of potassium, sulphur and magnesium from crop residues can be achieved from surface placement, with the release of potassium and sulphur managed by modifying residue particle size through appropriate harvesting, ploughing or sowing implement selection. High nutrient uptake crops and plant parts where they can be economically viable to grow or separated by the harvesting technique are particularly valuable as sources of nutrients and soil organic matter.
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Darvishvand, Taher Mehrdad. "A virtual nozzle for modeling pesticide spray deposition in a plant canopy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ35792.pdf.
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Birtle, Alan John. "Development of controlled-release pesticide formulations for use against plant parasitic nematodes." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37642.
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Kopittke, Peter Martin. "Limitations to plant root growth in highly saline and alkaline bauxite residue /." [St. Lucia, Qld.], 2004. http://adt.library.uq.edu.au/public/adt-QU20040913.094109/index.html.
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Si, Weiduo. "The effect of plant residue decomposition on microbial community composition in soil." Thesis, University of Newcastle Upon Tyne, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324866.
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Southwell, Rebecca Victoria. "Exploring the reproducibility and environmental realism of pesticide fate processes in regulatory systems." Thesis, University of Warwick, 2018. http://wrap.warwick.ac.uk/101653/.
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Pesticides are vital for controlling agricultural pests and increasing crop yields; however, they can have detrimental effects on the environment and human health. Regulatory laboratory studies need to be carried out to assess the risks of a pesticide before it can be produced and sold. These regulatory studies tend to poorly predict pesticide fate and degradation in the field, likely due to specified test conditions not accurately representing the environment. This thesis focuses on the potential for adding greater environmental realism to regulatory-type tests, using the fungicide isopyrazam in OECD 308- and 309-type studies. Regulatory tests are carried out under dark conditions. Microcosm studies were conducted in the presence of non-UV light to minimise photolysis, yet include phototrophic transformation; there was significantly more biodegradation in illuminated microcosms compared to those carried out in the dark, in which there was little degradation. The effect was more pronounced in water-sediment microcosms compared to water-only microcosms, as the sediment provided a platform for phototrophic biofilm development. Regulatory tests do not consider temporal variation in the microbial composition of environmental inoculum. Experiments carried out over two years showed that the outcome of tests, in terms of both degradation and mineralisation, were variable with inocula collected at different time periods from the same river location. Regulatory tests are also carried out statically. Recirculating microflume experiments showed that flowing water increased dissipation compared to static systems, regardless of light treatment. This suggests regulatory tests are not properly representing flowing aquatic systems, e.g. rivers. Lastly, regulatory tests are carried out on a small scale. Although there was little effect on pesticide decline in different sized microcosms, in the larger microflumes, dissipation occurred even under dark conditions. A number of Operational Taxonomic Units were specific to the microflumes suggesting that, on a larger scale, there was a wider variety of microorganisms that better reflected the environment. This work provides evidence for potential modifications to regulatory tests and insight into non-standard tests that industry could include in regulatory submissions.
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Amin, Bilal Ahmad Zafar. "Rôle des enzymes lignocellulolytiques dans le processus de biodégradation de résidus végétaux dans les sols : Influence de la qualité des résidus sur l’efficacité des enzymes et leur dynamique." Thesis, Reims, 2012. http://www.theses.fr/2012REIMS029/document.
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La décomposition des résidus végétaux joue un rôle essentiel dans le cycle biogéochimique des éléments nutritifs et influence le fonctionnement des écosystèmes. La composition biochimique intrinsèque des résidus végétaux est un facteur clé qui influe sur les processus de décomposition dans le sol tandis que la majorité des réactions biochimiques dans le sol, liées à la biodégradation des résidus végétaux, sont catalysées par des enzymes extracellulaires produites par les microorganismes. L'objectif global de cette étude était d'acquérir des connaissances fondamentales concernant l'impact de la qualité des résidus sur les fonctions microbiennes du sol et les modes d'intervention des enzymes du sol interviennent dans la décomposition des résidus végétaux. Cet objectif a été atteint en trois parties visant à : 1) déterminer le rôle des communautés initiales des résidus i.e. les microorganismes et leurs enzymes provenant des compartiments épiphytes et endophytes, et l'effet de la qualité des résidus végétaux sur les cinétiques des enzymes extracellulaires au cours du processus de décomposition dans le sol 2) étudier l'effet des fonctions microbiennes du sol (biomasse microbienne et enzymes extracellulaires) liées à la minéralisation sur la décomposition ultérieure de résidus introduits dans le même sol 3) explorer les interactions entre la disponibilité en azote et la décomposition des composés phénoliques par l'action des activités oxydo-réductases, et développer une méthode pour mesurer ces activités dans des sols contrastés en utilisant un seul substrat. L'approche générale de cette étude a été de sélectionner les résidus végétaux de qualité chimique variable pour obtenir des cinétiques contrastées de minéralisation du C. Le maïs (Zea mays L.) a été choisi comme plante modèle en raison de variations chimiques et structurales (Mexxal, F2, F2bm1, F292bm3) des parties aériennes (feuilles, entre-nœuds) et souterraines (racines). Des tiges de lin marqué au 13C ont été utilisées pour quantifier avec précision la minéralisation du carbone dans les différents réservoirs de carbone. Afin d'évaluer les relations entre la qualité des résidus végétaux et les fonctions biologiques associées au sol, des expériences en microcosmes contrôlés ont été réalisées en utilisant des sols agricoles et forestiers. La minéralisation du carbone, les caractéristiques chimiques des résidus (teneurs en C et N, les sucres totaux et lignine), la biomasse microbienne et les activités enzymatiques (L-leucine aminopeptidase (LAP), cellobiohydrolase (CBH-1), xylanase, cellulase et la laccase) ont été déterminées à différents stades de décomposition. Les résultats de la première étude ont indiqué que les activités de micro-organismes épiphytes et endogènes étaient du même ordre de grandeur dans le cas des racines, tandis que les activités des enzymes spécifiques (cellulase, xylanase et laccase) étaient fortement corrélées à la dégradation de leurs substrats cibles (glucanes, xylanes et lignine, respectivement). Dans la seconde étude, l'addition répétée de résidus a eu peu d'effet sur la biomasse microbienne et la dynamique enzymatique, sauf la LAP et la laccase. Ces résultats suggèrent que la qualité des résidus végétaux est le principal facteur déterminant les modes d'action de la biomasse microbienne et de leurs enzymes extracellulaires durant le processus de décomposition dans le sol. Les résultats de la dernière étude ont démontré que l'addition d'azote réprimait la minéralisation du carbone des résidus les moins lignifiés (F2, F2bm1), mais n'a pas affecté celle du résidu plus lignifié (F292bm3) au cours de la décomposition à long terme. L'ABTS est apparu comme un meilleur substrat que le L-DOPA, le pyrogallol et le TMB pour estimer les activités phénoloxydase et peroxydase.Mots clés: décomposition, biomasse microbienne, enzymes extracellulaires, qualité des résidus, maïsPlant residue decomposition plays a pivotal role in the biogeochemical cycling of nutrients and influences ecosystem functioning. The intrinsic biochemical composition of plant residues is a key factor influencing decomposition processes in soil while the majority of biochemical reactions in soil, related to the biodegradation of plant residues, are catalyzed by extracellular enzymes produced by microorganisms. The overall goal of this research study was to gain fundamental knowledge regarding the impact of residue quality on soil microbial functions and the principles by which soil enzymes mediate plant residue decomposition. This goal was achieved in three parts: 1) to determine the role of the initial residue community i.e. microorganisms and enzymes from the epiphytic and endophytic compartments and effect of plant residue quality on the extracellular enzyme kinetics during the decomposition process in soil 2) to investigate the effect of soil microbial functions (microbial biomass and extracellular enzymes) on the subsequent residue decomposition in the same soil 3) to explore the interactions between nitrogen availability and the decomposition of phenolic compounds through the action of oxydo-reductase enzymes activities and to develop a method to measure these activities in contrasted soils using a single substrate. The general approach of this study was to select plant residues with variations in their chemical quality to obtain contrasted C mineralization kinetics. Maize (Zea mays L.) was selected as a model plant because of variations in chemical and structural characteristics (Mexxal, F2, F2bm1, F292bm3) of aerial (leaves, internodes) and underground parts (roots). 13C-labeled flax stems were used to quantify accurately carbon mineralization in different carbon pools. To assess the relationships between plant residue quality and associated soil biological functions, controlled microcosm experiments were performed using agricultural and forest soils. Carbon mineralization and chemical characteristics (C and N contents, total sugars and lignin contents) of the plant residue, microbial biomass and enzyme activities (L-leucine aminopeptidase (LAP), cellobiohydrolase (CBH-1), xylanase, cellulase and laccase) were determined at different stages of decomposition. The results of first study indicated that activities of epiphytic and endogenic microorganisms were of the same order of magnitude in case of roots while the activities of specific enzymes (cellulase, xylanase and laccase) were highly correlated to the degradation of their target substrates (glucans, xylans and lignin, respectively). In the second study, little effect of repeated residue addition was observed on microbial biomass and enzyme dynamics except LAP and laccase. These results suggest that plant residue quality is the main factor which determines the fate/patterns of microbial biomass and their extracellular enzymes during decomposition process in soil. The results of last study demonstrated that nitrogen addition repressed the carbon mineralization of less lignified residues (F2, F2bm1) but did not affect more lignified residue (F292bm3) in long term decomposition. For estimation of phenol oxidase and peroxidase activities, ABTS appeared as a better substrate than L-DOPA, pyrogallol and TMB.Key words: decomposition, microbial biomass, extracellular enzymes, residue quality, maize
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Pessini, Milena Martins de Oliveira. "Resíduos de acetamiprid e thiamethoxam em tomate estaqueado (Lycopersicon esculentum Mill.), em diferentes modalidades de aplicação." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-15072003-141133/.
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No final dos anos 80, intensificaram-se as preocupações com os danos provocados à saúde do trabalhador rural e ao meio ambiente devido o uso indiscriminado de agrotóxicos. A descoberta de novos grupos de inseticidas, menos tóxicos e agressivos ao meio ambiente, vieram amenizar o problema. Entretanto, seus efeitos residuais ainda são pouco estudados, o que motivou esta pesquisa. Este trabalho visou avaliar o efeito dos inseticidas acetamiprid e thiamethoxam, pertencentes ao grupo dos neonicotinóides em diferentes modalidades de aplicação, com a finalidade de reduzir o número de pulverizações na cultura do tomate, eliminando seus efeitos negativos sobre o meio ambiente, bem como evitar a contaminação desse inseticida sobre os aplicadores. O ensaio foi realizado no campo experimental de tomate envarado no Departamento de Entomologia, Fitopatologia e Zoologia da ESALQ/USP, utilizando o cultivar Santa Clara, sendo realizados três tipos de aplicações: a) band-aid, que consistiu em misturar os inseticidas a um gel seco, colocando-se estes produtos em um saquinho de papel e envolvendo-os a uma fita adesiva, sendo colocados no colo das plantas; b) sachê, onde os inseticidas foram misturados com o gel seco e acondicionados em sachês, sendo colocados junto à raiz das mudas por ocasião do plantio; c) convencional, onde os inseticidas foram pulverizados com aplicador manual costal. A análise dos resíduos em frutos e folhas foi realizada por técnica de cromatografia líquida (HPLC) e, como resultado, constatou-se que: em tratamentos onde acetamiprid foi aplicado, todos apresentaram resíduos abaixo do mínimo detectável pela técnica HPLC; e, em tratamentos com thiamethoxam, somente em folhas onde o produto foi aplicado na forma de sachê e pulverização, foram observados resíduos, 0,06 e 0,3 mg/kg, respectivamente. O LMR (limite máximo de resíduo) para acetamiprid e thiamethoxam em frutos de tomate é de 0,5 e 0,02 mg/kg, respectivamente. Das análises realizadas, não detectou-se resíduos nos frutos analisados, somente sendo encontrados nas folhas. Pôde-se concluir que os métodos de aplicação analisados não apresentam problemas quanto à toxicidade ao meio ambiente e trabalhadores e resíduos. A área apresentou infestação de mosca branca, o que possibilitou a avaliação de controle da praga pelos produtos testados, nas diferentes modalidades de aplicação. Nos tratamentos onde acetamiprid e thiamethoxam foram aplicados em pulverização, o controle foi satisfatório. Quando aplicados na forma de sachê e band-aid, o controle foi menos satisfatório, porém, com a vantagem de não poluir o meio ambiente, bem como o evitar exposição do aplicador e dos inimigos naturais aos produtos.In the end of 80´s, careful was enhanced by rural worker health and environmental damages because of pesticides indiscriminated applications. The development of new insecticides groups, less toxic and aggressive to environment came to minimize the problem. However, their residue effects are not studied as it must be, and this was the reason of this research. This work aimed to evaluate the effect of the neonicotinoid insecticides acetamiprid and thiamethoxam, from different application methods, aiming to study the possibility of decreasing the number of sprays on tomato crop, removing their negative effects on environment, and avoid rural workers contamination. This trial was carried out on staked tomato crop in the Department of Entomology, Phytopathology and Zoology of ESALQ/USP, using Santa Clara tomato cultivar in three application methods: a) band-aid, that consisted in mix the insecticides with a dry gel, placed them into a little paper bag, wrapped up with an adhesive tape and arranged it on the plants neck; b) sachet, where insecticides were mixed with a dry gel and placed into a little paper bag, and they were arranged with the plant roots during the planting; c) conventional, where the insecticides were sprayed with a back sprayer. Residue analyses of tomato fruits and leaves were done by HPLC technique, and the results were: all treatments where acetamiprid were applied showed residue levels lower than the minimum detectable by HPLC technique; treatments with thiamethoxam, residues were observed only in leaves, when applied in sachet and conventional methods, at 0.06 and 0.3 mg/kg, respectively. The official tolerance to acetamiprid and thiamethoxam in tomato fruits are 0.5 and 0.02 mg/kg, respectively. The analyses, residues showed non detectable in fruits. The application techniques checked did not rise problems with environmental and rural workers based in their toxicities and residues. The experimental field showed whitefly infestation, and made possible control evaluation of this pest by the tested products, from different application methods. Treatments where acetamiprid and thiamethoxam were applied in conventional method, showed better pest control. When applied on sachet and band-aid methods, control was satisfactory; however, these methods have the advantage of lower environment polution, rural worker exposition to products and preservation of natural enemies mortality.
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Ademoyegun, Olufemi Temitope. "Evaluation of some pharmaceutical and personal care products and pesticide residues in selected wastewater treatment plants and receiving watersheds in Eastern Cape, South Africa." Thesis, University of Fort Hare, 2017. http://hdl.handle.net/10353/2922.
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Emerging organic contaminants (EOCs) have been the focus of global environmental research for over three decades. EOCs have caused widespread concern due to their extensive use. As EOCs were designed to correct, enhance or protect a specific physiological, their target effects in humans and/or farm stocks are relatively well known and documented. However, there is limited knowledge about their unintended effects in the environment. To address the occurrence, distribution and fate of EOCs in the environment, efficient and reliable analytical methods are needed. The relatively low concentration, high polarity, and thermal lability of some EOCs, together with their interaction with complex environmental matrices, make their analysis challenging. Sample preparation followed by GC or HPLC separation and mass spectrometry (MS) detection has become the standard approach for evaluating EOCs in environmental samples. Physicochemical properties of EOCs range from highly water-soluble (hydrophylic) to highly water-insoluble (hydrophobic). Two groups of these EOCs were considered for study in this work. Pharmaceutical and personal care products (PPCPs) were comprehensively studied in five wastewater treatment plants and their receiving watersheds in Amathole districts in Eastern C ape, South Africa. PPCPs have been widely reported in wastewater influents, effluents, receiving rivers and biosolids, but reports of their occurrence in all these matrixes have been limited by the difficulty of analysis. Therefore, a comprehensive validation of methods was carried out on the influents, effluents, sludge and soil from the irrigated golf course where the effluent of one of the study sites was being used for over three decades now for irrigation. In all, thirteen PPCPs from five therapeutic groups were selected for study in this work because of their administering rate and availability of analytical instrument. Good limit of detection (LOD) and limit of quantification (LOQ) were achieved for the method used. The LOD for the aqueous Three different technologies were employed for the treatment of wastewater in the five selected wastewater treatment plants (WWTPs) and study was carried out to evaluate their ability to eliminate the selected compounds from the influents to the effluents using statistical analysis (ANOVA) at p<0.05 on the percentage removal rate across the three plants. The results had shown eight of the compounds having no significant difference among the treatment operations, whereas the remaining five compounds varied significantly among the treatment technologies under investigation. Principal component analysis was performed on the concentration of PPCPs, their removal rate and also on the physicochemical and treatment operation parameters. Hydraulic retention time (HRT) had correlation coefficient, r = 0.90 with the concentration of PPCPs and removal rates. Furthermore, occurrences, seasonal variation, mean concentration distribution pattern of the compounds, and temporal evaluation of the mean concentration of the pharmaceutical compounds in the five WWTPs during one year of sampling were considered. The results revealed that five products which were diclofenac, ibuprofen, paracetamol, triclosan and diethyl toluamide (DDET) were predominant among the PPCPs in all the WWTPs. The removal efficiency was highest in caffeine with 96 percent, and the lowest was obtained with carbamazepine (4 percent). Risk quotient of the concentration of PPCPs in the effluents and receiving waters was determined to assess their chronic toxicity at three trophic levels: fish, algae and matrixes studied ranged from 0.01 μg/L to 0.25 μg/L, and the LOQ from 0.02 μg/L to 0.78 μg/L. In the solid matrixes, LOD varied from 0.01 ng/g to 0.65 ng/g, and the LOQ between 0.08 ng/g and 5.17 ng/g. Better recovery efficiency was obtained with this mixture of solvents, acetone: dichloromethane (1:1), for the recovery of the five therapeutic groups in the solid matrixes using ultrasonication- assisted techniques. The results show percentage recovery values ranging from 68.8 percent to 107.5 percent diaphian. According to the environmental risk assessment results, ibuprofen and triclosan were found to be the most critical compounds due to their high risk quotient values. These findings will, therefore, help in the future evaluation of the efficiency of different treatment technologies in the removal of various PPCPs from the wastewater and their sustainable management in the aquatic resources in Eastern Cape, South Africa. For the lipophilic organochlorine pesticides (OCPs), the limits of detection (LODs) of the tested congeners varied from 0.04 ng/g (α-BHC) to 0.49 ng/g (endosulfan sulfate) and the limits of quantification ranging from 0.22 ng/g (aldrin) to 2.17 ng/g (δ-BHC).
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MORACCI, LUIZ F. S. "Residuos de agrotoxicos em lodo de estacao de tratamento de agua: validacao de metodologia analitica utilizando cromatografia liquida acoplada a espectrometria de massas em TANDEM (LC-MS/MS)." reponame:Repositório Institucional do IPEN, 2008. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11734.
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Made available in DSpace on 2014-10-09T12:55:14Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:06:02Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Tüttinghoff, Hildegard. "Pesticide use in plant protection : descriptive analysis of decision making among rice farmers in Central Thailand /." Kiel : Wiss.-Verl. Vauk, 1991. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=002634473&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Ribeiro, Inês de Amaral. "Validação de técnicas analiticas para determinação de residuos de pesticidas em vinho." Master's thesis, ISA, 2010. http://hdl.handle.net/10400.5/3076.
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Mestrado em Engenharia Alimentar - Instituto Superior de AgronomiaVine is one of the most important crops in Portuguese agriculture. To counteract the effects of various diseases and pests that may occur in vineyards, a great part of the total pesticide consumption in Portugal is dedicated to this crop. Hence, it is of great importance to study the the presence of pesticide residues in wine. Food is the basis of human life, and wine is an important part of a regular diet of populations, as well as one of the most widely consumed beverages. therefore contamination with toxic pesticides leads to severe effects on human health. Thus, it is essential to use control measures and/or reduction of these toxic residues products. Currently, the analysis of pesticide residues in wine is usually done by applying chromatographic methods, mainly by gas chromatography. Spectroscopic methods may also be used and are probably the most used methods for the qualitative and quantitative determination of organic and inorganic compounds. In these respects, this study focused on the validation of analytical methods for the determination of pesticide residues in wine. To this end, five pesticides were selected based on their reported appearance in wine grapes and wines, as well as their toxicological characterization. The performance of a method for determination of dithiocarbamates residues in wines by molecular absorption spectrophotometry was validated based on standards EN 12396-1 and NP EN ISO IEC 17025. Calibrations were performed in the range 0,25 - 1,25 mg CS2/L wine and the statistical parameters were determined by linear regression using Microsoft Excel Data Analysis. An adjustment of experimental points to a first degree polynomial was noted by visual inspection of calibration curve, hence, the response could be considered linear in the work range. The linearity of the method was verified by the Pearson correlation coefficient, a value that was always equal or superior to 0,995, by the random distribution of residual values relative to zero and by the existence of a constant slope and a relatively small intercept (order of -10-2), in accordance with Beer's Law. The sensitivity of the method was demonstrated by the mean standard deviation of the calibration curve, which had a value of 0,06 mg/L. The selectivity of the method was also evaluated by the analysis of blanks of wines and no interference of the matrix was observed. The intermediate precision of the method was shown by the average relative standard deviation of 14 %. To evaluate the accuracy of the method, samples fortified with pesticides at three levels were analyzed. Based on the values obtained from these fortifications, a mean recovery of 93 % could be calculated. The limit of quantification was also tested experimentally and calculated to be 0,4 mg CS2/L wine , with a standard deviation of 19,6 %. These results indicate that the method is in accordance with the requirements of document SANCO/10684/2009, which applies to pesticide residues analysis in food and feed. __________________________________________________________________________ v Seventeen samples of different wines were analyzed and no residues of dithiocarbamates were detected. For the determination of pesticide residues in wine by gas chromatography it is necessary to extract them first to an organic phase. This sample preparation is very time consuming and occupies over 80% of the total analysis time. Subsequently the current methods of liquid-liquid extraction and the extraction methods for dispersed solid phase extraction (dSPE) of pesticide residues (chlorpyrifos, dimethoate, metalaxyl and penconazole) were also evaluated in the present study. Results indicated that it appears possible to replace the current methods of liquid-liquid extraction by procedures of dSPE extraction which would imply a great reduction in sample preparation time. Additional studies are needed in these regards, in particular to extend extraction procedures to other analytes and to verify results of these procedures whengaseous or liquid chromatography with mass spectrometer systems are used. It is also important to further study the influence of several factors (e.g. pH, extraction temperatures, temperature program) in both extraction and instrumental analysis methods
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Mackowiak, Cheryl L. "The Efficacy of Plant Residue Degradation Products on Phosphorus, Iron, Iodine, and Fluorine Bioavailability to Plants." DigitalCommons@USU, 2001. https://digitalcommons.usu.edu/etd/6758.
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Plant and animal wastes degrade in soils to form relatively stable humified compounds, which form ion complexes that affect the bioavailability of elements in the soil solution. Hydroponic studies with wheat and rice were conducted to characterize the effect of humic acid (HA) on phosphorus (P), iron (Fe), fluorine (F), and iodine (I) bioavailability. Ferrihydrite [Fe(OH)3] precipitation was greater on root surfaces without HA or synthetic chelates. Oxides such as ferrihydrite strongly adsorb P and provide exchange sites for metals. HA reduced this precipitate and increased P and Fe uptake. Humic acid had no effect on F toxicity in rice, where solution levels above 0.5 mM F inhibited growth. Data supported the hypothesis that in moderately acidic solutions (pH< 6), F uptake is primarily as HF rather than F. Doubling solution Ca caused a 10-fold increase in root surface CaF2 precipitates, but the additional Ca did not decrease F toxicity. Calcium levels above 1 mM caused HA to flocculate over time, but the addition of F reduced flocculation by competing with HA for Ca. The majority of shoot F was apparently associated with the middle lamella, suggesting that F may bind with phosphates and pectate-Ca. Organic matter promotes aqueous iodine (I2(aq)) reduction to I-, a less toxic species. HA reduced 12( aq) toxicity by 50%. In solutions without HA, 6.5 μM h(aq) was more toxic than 30 μM I-. Humic acid had no effect on I- uptake or toxicity, where I- and IO3- were toxic to rice at 10 and 100 μM, respectively. These data were used to model element cycling through plants in a regenerative human life support system for NASA 's Advanced Life Support program, where HA, P, Fe, F, and I from plant residues and human wastes are recycled to the crop production system.
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Cogo, Juliana Pivetta. "Determinação de resíduos de pesticidas em plantas de arroz empregando QuEChERS modificado e GC-ECD." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/10439.
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Rice culture is an activity that has currently been gaining more importance due to its use in human feeding, allowing enough food and acceptable quality to the population. There is a great concern regarding the intensive use of pesticides, the main strategy employed
in the countryside to combat and prevent plagues, as well as the residues resulting from such practice. This paper has been developed and validated on an analytical procedure, using the QuEChERS modified extraction approach and gas chromatography with electron-capture detection (GC-ECD) for the determination of residual insecticides
lambda-cyhalothrin and bifenthrin and azoxystrobin fungicides and trifloxystrobin in rice plants. The QuEChERS modified method was applied in an initial stage of extraction using 3.0 g of rice plants in which was added 15 mL of acetonitrile containing 1% (v/v) acetic acid, followed by a partition step after the addition of a mixture of anhydrous salts (3 g of magnesium sulphate and 1.7 grams of sodium acetate). Next, the clean-up stage
was carried out 4 mL extract using 200 mg of activated charcoal and 600 mg of magnesium sulfate and the analysed by GC-ECD using an apolar DB-5 column. During method validation, LOD; LOQ; linearity; precision (repeatability and intermediate precision); and accuracy, evaluated in terms of recovery, were determined. Using this method, LOQ quantities were 1 mg kg-1 for azoxystrobin and 0.05 mg kg-1 for lambdacyhalothrin, bifenthrin and trifloxystrobin. The analytical curves presented linearity between 0.01 and 1.0 mg L-1, with coefficient of determination greater than 0.993. The method had shown good precision, with RSD values smaller than 19.0%, and accuracy, with recoveries between 71.2 and 103.6%. The method was considered adequate to the analysis of pesticides in rice plants, considering that all validation parameters meet the
levels required for validation of chromatographic methods. After being validated, the method was applied to the study of the residual concentration of pesticides in rice
plants, from rice crops irrigated with an experiment carried through at the UFSM Campus; where the pesticides azoxystrobin, bifenthrin, lambda-cyhalothrin, and
trifloxystrobin were individually applied in 2007/2008 harvest. All pesticides in this study were detected up to approximately twenty (20) days after being applied.A cultura do arroz é uma atividade de importância cada vez maior pela sua utilização na alimentação humana, garantindo alimento suficiente e de qualidade para a população. A grande preocupação é o uso intensivo de pesticidas; principal estratégia no campo para o combate e a prevenção de pragas, e os resíduos decorrentes desta prática. Neste trabalho, desenvolveu-se e validou-se um procedimento analítico, utilizando o método de extração QuEChERS modificado e Cromatografia Gasosa com Detecção por Captura de Elétrons (GC-ECD) para a determinação residual dos inseticidas bifentrina e lambda-cialotrina e dos fungicidas azoxistrobina e trifloxistrobina em plantas de arroz. O método QuEChERS modificado consistiu em uma etapa de extração inicial utilizando 3,0 g de plantas de arroz na qual foi adicionado 15 mL de acetonitrila contendo 1% (v/v) de ácido acético, seguida por uma etapa de partição após a adição de uma mistura de sais anidros (3 g de sulfato de magnésio e 1,7 g de acetato de sódio). Na seqüência foi realizada a etapa de clean-up de 4 mL de extrato com 20 mg de carvão ativado vegetal e 600 mg de sulfato de magnésio e a análise por GCECD utilizando-se coluna apolar DB-5. Na validação do método determinou-se LOD, LOQ, linearidade, precisão (repetitividade e precisão intermediária) e exatidão, avaliada pela recuperação. Os valores de LOQ do método foram 1,0 mg kg-1 para azoxistrobina e 0,05 mg kg-1 para lambda-cialotrina, bifentrina e trifloxistrobina. As curvas analíticas apresentaram linearidade entre 0,01 e 1,0 mg L-1, com valores de coeficiente de determinação maiores que 0,993. O método apresentou boa precisão, com valores de RSD inferiores a 19,0%, e boa exatidão, com recuperações entre 71,2 e 103,6%. O método foi considerado adequado à análise dos pesticidas em plantas de arroz, visto que todos os parâmetros de validação atendem os limites sugeridos para validação de métodos cromatográficos. Após ser validado, o método foi aplicado em um estudo da concentração residual dos pesticidas em plantas de arroz, oriundas de lavoura de arroz irrigado de um experimento realizado no Campus da UFSM, onde foram aplicados separadamente os pesticidas azoxistrobina, bifentrina, lambda-cialotrina e trifloxistrobina, na safra 2007/2008. Todos os pesticidas em estudo foram detectados até aproximadamente 20 dias após a sua aplicação.
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Carvalho, Stella Pacheco Lombardi de. "Resíduos de deltametrina e de carbaril em dois sistemas de condução da cultura de tomate estaqueado (Lycopersicon esculentum Mill) e sua eficiência no controle da broca-pequena-do-fruto Neoleucinodes elegantalis (Guenée, 1854) (Lepidoptera: Crambidae)." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-22092004-143434/.
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O objetivo deste estudo foi avaliar os inseticidas deltametrina e carbaril, de modo a abranger seus resíduos em dois sistemas de condução da cultura de tomate estaqueado (linha dupla, plantio comercial e linha simples, plantio experimental) e sua eficiência no controle da broca-pequena-do-fruto, a determinação dos resíduos nos substratos: frutos (visando à proteção à saúde pública), folhas e solo (como uma possível fonte de contaminação ambiental), a comparação dos níveis de resíduos encontrados nesses diferentes sistemas de condução, o controle obtido com os dois inseticidas e sistemas de condução e a comparação dos níveis de resíduos dos frutos com os LMRs (Limites Máximo de Resíduo) e intervalo de segurança estabelecidos pela legislação brasileira. O experimento foi conduzido no Município de Piedade, no Estado de São Paulo, Brasil. Consistiu em cinco tratamentos: (1) nove aplicações de deltametrina (Decis 25 CE) no plantio linha simples, (2) nove aplicações de carbarill (Sevin 480 SC) no plantio linha simples, (3) nove aplicações de deltametrina (Decis 25 CE) em linha dupla, (4) nove aplicações de carbaril (Sevin 480 SC) no plantio linha dupla e (5) controle. A primeira aplicação foi feita no início da fase de maturação do fruto e as seguintes em intervalos subseqüentes de 7 dias. As amostras de frutos foram colhidas com (-1), zero, 3, 5 e 10 dias após a última aplicação. As amostras de folha e solo foram coletadas com (-1), zero, 1, 3, 10 e 20 dias após a última aplicação. O método analítico consistiu na extração dos resíduos com acetato de etila, limpeza dos extratos em cromatografia de permeação em gel (GPC), e determinação quantitativa em cromatógrafo de gás equipado com detector de captura de elétrons (GLC/ECD) (deltametrina) e em cromatógrafo de gás equipado com detector seletivo de massas (GLC/MSD). Os resultados mostraram que os resíduos de deltametrina nos frutos no plantio comercial estavam abaixo de seu LMR ao final do intervalo de segurança; o mesmo não ocorreu com o carbaril que nos dois sistemas de condução, apresentou resíduos superiores ao seu LMR. Os resíduos maiores foram encontrados nas folhas, para ambos os inseticidas, constituindo assim, estas, uma possível fonte de contaminação ambiental. Os resíduos encontrados no solo foram baixos, no caso da deltametrina se aproximaram dos valores encontrados para o fruto e os de carbaril foram ainda menores que os do fruto, mostrando um baixo escorrimento da calda de saturação e conseqüentemente, um baixo potencial de contaminação do solo. O plantio experimental (linha simples) apresentou resíduos sempre maiores que o plantio comercial (linha dupla), sendo, em conseqüência, melhor o controle da praga nesses tratamentos.The objective of this study was to evaluate the insecticides deltamethrin and carbaryl, in order to study their residues, in two cultivation systems of staked tomato crop: experimental cultivation (single line) and commercial cultivation (double line) and their efficiency in the control of the fruit small borer, Neouleucinodes elegantalis (Guenée, 1854) (Lepidoptera: Crambidae), the determination of the residues in fruits (aiming the protection of public health), leaves and soil (like a possible source of environmental contamination), the comparison of residues found in these two different systems of cultivation, the control achieved with both insecticides and systems of cultivation and the comparison of the residues in fruits with the MRLs (Maximum Residue Levels) and safety intervals established by Brazilian legislation. The experiment was conducted Piedade County in the State of São Paulo, Brazil. It consisted of five treatments: (1) nine applications of deltamethrin (Decis 25 CE) in single line, (2) nine applications of carbaryl (Sevin 480 SC) in single line, (3) nine applications of deltamethrin (Decis 25 CE) in double line, (4) nine applications of carbaryl (Sevin 480 SC) in double line and (5) control. The first application was made at the begining of the fruit maturation stage, and the following ones in 7 days period scheduled. Fruit samples were collected one day before the last application (-1 day) and zero, 3, 5 and 10 days after the last application. Leaf and soil samples were collected one day before the last application (-1 day) and zero, 1, 3, 10 and 20 days after the last application. The analytical method consisted by extraction of residues with ethyl acetate, clean-up of the extracts by gel permeation chromatograph (GPC), and quantitative determination by gas chromatograph equipped with electron capture detector (GLC/ECD) (deltamethrin) and by gas chromatograph equipped with mass selective detector (GLC/MSD). The results showed that deltamethrin residues in fruits from commercial cultivation system (double line) were below MRL at the end of safety interval; as for carbaril residues they were above MRL in fruits from both cultivation systems. Higher residues were found on leaves, for both insecticides, being considered this as a possible source of environmental contamination. Soil residues were lower; as for deltamethrin the levels were similar to fruit, but for carbaril they were lower in as compared to fruits showing low drift from the saturated foliage and consequently, low potential of soil contamination. The experimental cultivation system (single line) always showed higher residue levels for both insecticides than the commercial one (double line), being, in consequence, better the insect pest control in these treatments.
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Kamota, Agathar. "Effect of BT maize on earthworm activity, silage quality and residue decomposition in the central Eastern Cape." Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/413.
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There are concerns that genetic modification of maize with Bacillus thuringiensis may influence its structural and chemical composition which, together with the Cry1Ab proteins, may affect agro-ecosystem processes and feed quality. This study was aimed at investigating the expression of Cry1Ab protein in leaves, stems and roots of Bt maize and the effect of genetic modification (MON810) on activity of earthworms, silage quality and decomposition of residues in the field. In 2009/10 four maize cultivars; DKC61-25B, DKC61-24, PAN6Q-321B and PAN6777 were planted. Expression of Cry1Ab in leaves, stems and roots was analyzed at 6, 8, 10 and 12 weeks after planting (WAP). Earthworms were also sampled from the same treatments at 6, 9 and 18 WAP. Two silage experiments were conducted using maize cultivars, DKC80-12B and DKC80-10 produced in the 2008/09 season and DKC61-25B, DKC61-24, PAN6Q-321B and PAN6777, produced in 2009/10. The silage was sampled at 0, 2, 4, 8, 15 and 42 days in 2008/09 and 0, 8 and 42 days in 2009/10 and analyzed for Ash Free Dry Matter, Crude Fiber, Neutral Detergent Fiber, Acid Detergent Fiber, Acid Detergent Lignin, Crude Protein and Total Digestible Nutrients. Two litter-bag decomposition studies were also carried out (i) in 2008 (surface applied) using maize cultivars DKC80-12B, DKC80-10 and DKC6-125 residues and (ii) in 2009 (soil incorporated) using DKC75-15B, CRN3505, PAN6Q-321B v and PAN6Q-121. Ash-free dry matter and Cry1Ab protein were measured throughout the incubation time. There were no differences between DKC61-25B and PAN6Q-321B in terms of expression of Cry1Ab in leaves, stems and roots over time. The Cry1Ab expression levels were in decreasing order: leaves > stems > roots. No effects of Bt maize on earthworm numbers and biomass were observed. There were no differences in all silages parameters except NDF and ADF, which were higher in the Bt maize silage than that of the non-Bt maize from the 2008/09 season. The Cry1Ab levels were essentially not reduced during ensiling. The maize residues (both Bt and non-Bt maize) degraded to similar levels, either when surface-applied or incorporated into soil but soil-incorporated residues decomposed faster than surface-applied ones. Cry1Ab degraded as the plant matrix decomposed. The findings suggested that maize genetically modified with the Bt MON810 event can be grown in the Central Eastern Cape without affecting earthworm numbers and biomass, silage quality and decomposition of maize residues.
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Johns, Josiah A. "Assessing Phosphorus Sources with a GIS-Based Phosphorus Risk Index in a Mixed-Use, Montane Watershed." BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6559.
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Elevated phosphorus (P) loading of freshwater lakes and reservoirs often results in poor water quality and negative ecological effects. Critical source areas (CSA) of P in the watershed can be difficult to identify and control. A useful concept for identification of a CSA is the P risk index (P Index) that evaluates the P risk associated with distinct source and transport pathways. The objectives of this study were to create a GIS model that adapts the Minnesota (MN) P Index for use at the watershed scale in a mixed-use, mountain environment, and to evaluate its effectiveness relative to field-based assessment. A GIS-based model of the MN P Index, adapted for montane environments and relying primarily on publicly available geospatial data, was created and applied in the Wallsburg watershed, located in the mountains of Central Utah. One necessary data input, P found in plant residue of common Utah ecosystems, was found lacking after literature review. We experimentally determined a range of observed values from multiple ecosystems to adapt and validate the GIS model. The GIS P Index was evaluated against the results of 58 field scale applications of the MN P Index conducted throughout the watershed. The field-scale analysis resulted in about 14% of the sites sampled being identified as high or very high risk for P transport to surface water. Spatially, these high risk areas were determined to be a geographic cluster of fields near the lower middle agricultural section of the watershed. The GIS model visually and spatially identified the same cluster of fields as high risk areas. Various soil test P scenarios were explored and compared to the known 58 site values. Soil test phosphorus had little effect on the GIS model's ability to accurately predict P risk in this watershed suggesting that high volume soil sampling is not always necessary to identify CSAs of P. Variable hypothetical livestock density scenarios were also simulated. The GIS model proved sensitive to variable P inputs and highlighted the necessity of accurate applied P source data. On average the model under-predicted the known field-site values by a risk score of 1.3, which suggests reasonable success in P assessment based on the categorical risk scores of the MN P Index and some potential for improvement. The GIS model has great potential to give land managers the ability to quickly locate potential CSAs and prioritizing remediation efforts to sites with greatest risk.
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Nguyen, Thi Hue, and Dinh Nghiem Ha. "Research on the status of chemical pesticide uses in agricultural activities in Phan Me commune, Phu Luong district, Thai Nguyen province." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-190448.
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Phan Me is a midland-mountainous commune of Phu Luong district, Thai Nguyen province, Vietnam where the agricultural activities are predominant occupation. The investigation on the use of plant protection products in here showed that chemical pesticides have been commonly used in agricultural activities. Although some local people have a good attitude in using plant protection products, the status of using chemical pesticides that were not recommended (like Vofatox) has been quite popular due to the old cultivation customs. The local people have not applied any measures for wastewater treatment, or plant protection product package treatment. Besides, the use of plant protection products in higher concentration than recommendation for vegetables or crops caused the residues of toxics in agricultural products as well as in cultivation soil. The accumulation of toxic residues in the environment is a serious matter of concern because of their significant impact on the environment, agricultural ecosystem and human healthPhấn Mễ là một xã trung du miền núi của huyện Phú Lương, tỉnh Thái Nguyên, Việt Nam với hoạt động sản xuất nông nghiệp là chủ yếu. Qua thực tế điều tra tình hình sử dụng thuốc bảo vệ thực vật (BVTV) tại đây cho thấy hầu hết các loại hình sản xuất nông nghiệp đều sử dụng thuốc BVTV. Một số người dân đã có ý thức trong việc sử dụng thuốc BVTV tuy nhiên do tập quán canh tác từ lâu đời nên việc sử dụng các loại thuốc bị khuyến cáo, chẳng hạn như Vofatox, vẫn còn khá phổ biến. Người dân chưa tiến hành các biện pháp để xử lý nước thải, bao bì, vỏ chai thuốc BVTV sau khi sử dụng. Bên canh đó, họ còn sử dụng thuốc BVTV không đúng liều lượng cho một số loại cây rau để lại dư lượng thuốc trên nông sản cũng như đất canh tác. Sự tích lũy dư lượng của những chất độc hại này trong môi trường là vấn đề đáng lo ngại do sự ảnh hưởng nghiêm trọng của chúng đối với môi trường sống, hệ sinh thái nông nghiệp và sức khỏe con người
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Alskaf, Kamal. "Conservation agriculture for sustainable land use : the agronomic and environmental impacts of different tillage practices and plant residue retention : farmer uptake of reduced tillage in England." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/51902/.
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Conservation Agriculture (CA) has potential benefits to the soil, crop yield, and the environment including reducing runoff, enhancing water retention and preventing soil erosion, in addition to increasing soil carbon sequestration and reducing greenhouse gas (GHG) emissions. Although CA is widely adopted in some areas of the world, it is still not widely adopted by UK farmers. The first overall aim of this project was to investigate the effects of tillage practice and residue retention, on soil physical properties, crop yield and GHG emissions. For this purpose, a split-plot field experiment was established on the University of Nottingham farm between September 2014 and August 2016. The main plot treatment was residue retention while cultivation practices were applied to the sub-plots and included three different tillage systems: no-tillage, minimum-tillage and deep ploughing. We used a novel analytical tool, X-ray Computed Tomography, to characterise the 3-D soil pore network in conjunction with a number of other soil physical properties such as bulk density, penetration resistance and shear strength. A range of portable chambers were used to detect the GHG emissions from soil and from soil-plant systems as influenced by the tillage and residue treatments. Winter wheat yield was not affected by the tillage treatments or residue retention in the first year, but, in the second year, no-tillage caused a 10% reduction in triticale yield compared to minimum-tillage and traditional ploughing. Multiple regression analysis showed that the lower triticale yield was partially explained by higher soil strength in the no-tillage plots, together with lower soil moisture content in summer. Our results show that while there is potential for climate change mitigation from no-tillage when the Net Ecosystem Exchange is considered, this effect could not be observed from soil emissions only. The second aim of this project was to assess the current level of reduced tillage (RT) uptake by UK farmers and the constraints for further adoption. A postal questionnaire was conducted in January 2016. This questionnaire found that only 7.0% of the arable land in England is under no-tillage and 47.6% is under minimum-tillage. The adoption of RT increased with an increase in farm size as it was the most adopted on farms >400 ha. Moreover, RT was adopted most on combinable crop farms. Weed management and slugs were identified as main challenges for RT adopters. Increasing uptake of CA from current levels will probably require policy intervention including financial incentives for growers during the early stages of the transition from ploughing to CA. This will encourage farmers to buy RT equipment and may help them to cover any potential yield reduction, if occurred, before the CA system stabilisation.
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MUNIZ, Maria Jacyelle dos Santos. "Influência dos inseticidas cipermetrina e metomil no desenvolvimento e promoção de crescimento vegetal das bactérias Burkholderia sp. UAGC867 e Pseudomonas sp. UAGC97." Universidade Federal Rural de Pernambuco, 2016. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6554.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Bacteria Plant Growth Promoting (BPGP) has been studied as environmental remediation, as many agricultural soils are contaminated by residue of pesticides. Among these bacteria are Burkholderia and Pseudomonas, which have the ability to grow in different environments, having the ability to conserve the environment through their activity to biodegrade polluting compounds. Thus, the objective of this study was to evaluate the potential of tolerance and degradation of bacteria Burkholderia sp. UAGC867 and Pseudomonas sp. UAGC97, in relation to the cypermethrin and methomyl insecticides, used to control Spodoptera frugiperda; the respirometric rate ground when influenced with the cypermethrin insecticide and bacterial strains; the effect of cypermethrin on the indole acetic acid production by BPGP and the influence of bacterial inoculation with cypermethrin in corn seeds. For the tolerance test inrelation to cypermethrin and methomyl insecticide , the strains UAGC867 and UAGC97 were cultivated in mineral liquid medium plus glucose and each treatment received 25-50-100 and 200 mg L-1 of each insecticide. The treatment control was free insecticide. Tha degradation test of insecticides by bacteria followed the same methodology, differing only in the absence of glucose treatments. The influence of bacterial inoculum and concentrations different of cypermethrin (0-25-50-100-200 mg L-1) in the soil, the experiment was conducted in microcosms installed in a greenhouse, and later collected 100 g ground and transferred to pots in order to evaluate the respiration rate of the soil in the laboratory. It was also evaluated the production of indole acetic acid (IAA) by PBPG, through the influence of cypermethrin insecticide in the field concentration. Finally, the strains Burkholderia sp. UAGC867 and Pseudomonas sp. UAGC97 were cultured in the presence and absence of cypermethrin (100 mg L-1) to evaluate the germination and growth of corn seed. The two bacteria evaluated were able to express growth in the presence of pesticides concentrations, demonstrating their tolerance for the same. Burkholderia sp. UAGC867 was able to degrade all methomyl concentrations, and 25 mg L-1 of the insecticide cypermethrin. Pseudomonas sp. UAGC97 exhibited degradation only in 25 mg L-1 methomyl insecticide. There carbon dioxide captured oscillations throughout the experiment, however, was not observed between treatments unclustering by principal component analysis. The IAA synthesis by BPGP was not inhibited by the insecticide cypermethrin, however, there was prominent production by Pseudomonas sp. UAGC97 on the seventh day of evaluation. There was no statistical difference between treatments evaluated in the germination speed index and the germination percentage. The assessments of plant growth promotion revealed that the cultivation of Burkholderia sp. UAGC867 in the presence of 100 mg L-1 cypermethrin stimulated the growth of shoots of corn seedlings, in addition to presenting significant results in fresh and shoot dry. The evaluated bacteria exhibit promoting characteristics of plant growth, with potential for more exploration of their interaction with the plant.
O uso de Bactérias Promotoras de Crescimentos em Plantas (BPCP) vem sendo estudado quanto a remediação ambiental, visto que muitos dos solos agrícolas estão contaminados pelo resíduo dos pesticidas. Dentre tais bactérias, estão os gêneros Burkholderia e Pseudomonas, que possuem a capacidade de crescer em variados ambientes, possuindo habilidade de conservar o meio ambiente, através de sua atividade em biodegradar compostos poluentes. Sendo assim, o objetivo do presente trabalho foi avaliar o potencial de tolerância e degradação das bactérias Burkholderia sp. UAGC867 e Pseudomonas sp. UAGC97, quanto aos inseticidas cipermetrina e metomil utilizados no controle da Spodoptera frugiperda; avaliar a taxa respirométrica do solo quando influenciada com o inseticida cipermetrina e as linhagens bacterianas; avaliar a influência da cipermetrina sobre a produção do ácido indol acético pelas BPCP e avaliar a influência da inoculação bacteriana, cultivada com cipermetrina, em sementes de milho. Para o teste de tolerância aos inseticidas cipermetrina e metomil pelas bactérias Burkholderia sp. UAGC867 e Pseudomonas sp. UAGC97, foi utilizado o meio mínimo mineral liquido modificado acrescido de glicose, onde cada tratamento recebeu 25-50-100 e 200 mg L-1 de cada inseticida, além do tratamento controle, insento de inseticida. Para o teste de degradação dos inseticidas cipermetrina e metomil pelas bactérias avaliadas, seguiu-se a mesma metodologia, diferindo apenas da ausência da glicose nos tratamentos. Para o teste da influência do inóculo bacteriano e das diferentes concentrações de cipermetrina (0-25-50-100-200 mg L-1) no solo, o experimento foi conduzido em microcosmos instalados em casa de vegetação, sendo posteriormente coletados 100g do solo e transferidos para potes afim de avaliar a taxa respiratória do solo, em laboratório. Também foi avaliado a produção do ácido indol acético (AIA) pelas BPCP, através da influência do inseticida cipermetrina na concetração de campo. E por fim, as bactérias Burkholderia sp. UAGC867 e Pseudomonas sp. UAGC97, foram cultivadas em meio na presença e na ausência do cipermetrina (100 mg L-1) afim de serem utilizados na avaliação de germinação e desenvolvimento do milho, sendo inculadas em sementes. As duas bactérias avaliadas conseguiram expressar crescimento na presença das concentrações dos inseticidas, demonstrando sua tolerância quanto ao mesmo. A Burkholderia sp. UAGC867 degradou o metomil em todas as concentrações, e mostrou degradação em 25 mg L-1, do inseticida cipermetrina,pelo método avaliado. Já a Pseudomonas sp. UAGC97 exibiu degradação apenas na concentração 25 mg L-1 do inseticida metomil. Houve oscilações de dióxido de carbono capturado entre os tratamentos avaliados, no entanto, não foi observado desagrupamenteo entre os tratamentos através da análise de componentes principais. A síntese do AIA produzido pelas BPCP, não foi inibido pelo inseticida cipermetrina, contudo, houve destaque da produção de AIA pela Pseudomonas sp. UAGC97 no sétimo dia de avaliação. Não houve diferença estatística entre os tratamentos avaliados no índice de velocidade de germinação e na percentagem de geraminação, contudo, nas avaliações de promocação de crescimento vegetal observou que o cultivo da Burkholderia sp. UAGC867 na presença de 100 mg L-1 cipermetrina estimulou o crescimento da parte aérea das plântulas de milho, além de apresentar resultados significativos na massa fresca e seca da parte aérea. As bactérias avaliadas exibem características de promoção de crescimento vegetal, apresentando potencial para exploração mais minunciosa da sua interação com a planta.
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Landzela, Besule. "Effects of BT Maize (MON810) crop and its residues on selected soil biological properties and N and P release in a sandy loam soil from Alice, Eastern Cape, South Africa." Thesis, University of Fort Hare, 2013. http://hdl.handle.net/10353/d1007542.
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There are apprehensions that genetic modification of maize with Bacillus thuringiensis (Bt) may have negative effects on soil biodiversity, ecosystem processes and functions. This study aimed at determining the effect of Bt maize crop, Bt maize residues and its genetic modification on microbial biomass carbon (MBC), selected enzyme activities, vesicular arbuscular mycorrhizal (VAM) fungi and N and P release patterns. The study was conducted under field, glasshouse and laboratory conditions. In 2010/2011 season, four maize cultivars; DKC 61-25B (Bt), DKC 61-24 (non-Bt), PAN 6Q-321B (Bt) and PAN6777 (non-Bt) were planted. Determination of MBC, enzyme activities and fungal spore count was done at 42, 70, and 105 days after planting (DAP). A loam soil amended with Bt or non-Bt maize leaf residues from a study of 2009/2010 season was incubated to investigate effects of Bt maize residues on MBC and soil enzyme activities. Leaf residues of Bt and non-Bt maize cultivars (DKC 61-25B, DKC 61-24, PAN 6Q-321B and PAN6777) were used and soil without residues was used as a control. Samples were collected at 7, 28 and 56 days of incubation (DOI). An incubation study was also carried out in the laboratory to determine the effect of Bt maize residues (i.e. leaf, stem and root) and its genetic modification on N and P release patterns. Residues of DKC 61-25B, DKC 61-24, PAN 6Q-321B and PAN6777and soil without residues as a control were incubated in the laboratory. After destructive sampling at 0, 7, 14, 28, and 56 DOI, N in the form of NH4-N and NO3-N and P mineralisation were determined. Amendment of soil with residues enhanced MBC (p < 0.05) at all the sampling dates. For example MBC increased from 95 in the control to 146.3 mg/kg in the DKC 61-25B treatment at the end of the glasshouse trial. In the field DKC 61-25B had 9.1 mg/kg greater MBC than DKC 61-24, while PAN 6Q-321B had 23.9 mg/kg more MBC than PAN6777 at the end of the trial. However, no differences (p < 0.05) were observed in enzyme activities under field and glasshouse conditions except for dehydrogenase that had greater activity where DKC 61-25B and PAN 6777 were grown. There were no differences between the type of residues (Bt and non-Bt) on enzyme activities tested. However, differences were observed among the sampling dates. No effects of Bt maize crop on fungal spore count were observed. Similarly no differences were observed in leaf, stem and root tissues composition between Bt and non-Bt maize cultivars. Net N and P mineralisation from Bt maize cultivars did not differ from that of non-Bt maize cultivars. However, differences were observed among the cultivars. The results of this study suggested that Bt maize with Bt MON810 event can be grown in the central region of the Eastern Cape (EC), South Africa without affecting MBC, soil enzyme activities, VAM, and release of N and P nutrients from its residues.
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Nguyen, Thi Hue, and Dinh Nghiem Ha. "Research on the status of chemical pesticide uses in agricultural activities in Phan Me commune, Phu Luong district, Thai Nguyen province: Research article." Technische Universität Dresden, 2014. https://tud.qucosa.de/id/qucosa%3A29084.
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Phan Me is a midland-mountainous commune of Phu Luong district, Thai Nguyen province, Vietnam where the agricultural activities are predominant occupation. The investigation on the use of plant protection products in here showed that chemical pesticides have been commonly used in agricultural activities. Although some local people have a good attitude in using plant protection products, the status of using chemical pesticides that were not recommended (like Vofatox) has been quite popular due to the old cultivation customs. The local people have not applied any measures for wastewater treatment, or plant protection product package treatment. Besides, the use of plant protection products in higher concentration than recommendation for vegetables or crops caused the residues of toxics in agricultural products as well as in cultivation soil. The accumulation of toxic residues in the environment is a serious matter of concern because of their significant impact on the environment, agricultural ecosystem and human health.Phấn Mễ là một xã trung du miền núi của huyện Phú Lương, tỉnh Thái Nguyên, Việt Nam với hoạt động sản xuất nông nghiệp là chủ yếu. Qua thực tế điều tra tình hình sử dụng thuốc bảo vệ thực vật (BVTV) tại đây cho thấy hầu hết các loại hình sản xuất nông nghiệp đều sử dụng thuốc BVTV. Một số người dân đã có ý thức trong việc sử dụng thuốc BVTV tuy nhiên do tập quán canh tác từ lâu đời nên việc sử dụng các loại thuốc bị khuyến cáo, chẳng hạn như Vofatox, vẫn còn khá phổ biến. Người dân chưa tiến hành các biện pháp để xử lý nước thải, bao bì, vỏ chai thuốc BVTV sau khi sử dụng. Bên canh đó, họ còn sử dụng thuốc BVTV không đúng liều lượng cho một số loại cây rau để lại dư lượng thuốc trên nông sản cũng như đất canh tác. Sự tích lũy dư lượng của những chất độc hại này trong môi trường là vấn đề đáng lo ngại do sự ảnh hưởng nghiêm trọng của chúng đối với môi trường sống, hệ sinh thái nông nghiệp và sức khỏe con người.
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Sgarbiero, Eduardo. "Resíduos de pirimifós-metil em grãos de trigo, milho e milho pipoca, em alguns de seus produtos processados e ação residual desse inseticida sobre Sitophilus spp. (Coleoptera, Curculionidae)." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-26072002-155740/.
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Os objetivos do presente trabalho foram avaliar a ocorrência / persistência / degradação de resíduos do inseticida organofosforado pirimifós-metil em grãos de trigo, milho e milho pipoca e em alguns de seus produtos processados, bem como a ação residual desse inseticida sobre Sitophilus spp. (Coleoptera, Curculionidae). O tratamento dos grãos foi realizado de modo a se obter a concentração teórica de 12 mg.kg-1 (ppm) de pirimifós-metil, tendo sido aplicados o equivalente a 5 litros de solução por tonelada de grãos. As amostras para estudos de resíduos foram tomadas aos zero, 15, 30, 60, 120 e 240 dias após o tratamento. O método analítico consta da extração dos resíduos com acetona, limpeza com partição acetonitrila/hexano seguida de coluna cromatográfica de sílica eluída com mistura de hexano+acetona (9/1, v/v). A determinação quantitativa foi feita por técnica de cromatografia em fase gasosa, usando-se cromatógrafo equipado com detector fotométrico de chama (GLC/FPD). Foram analisadas 264 amostras no total, sendo 72 de grãos cereais e 192 de seus produtos processados. Para os estudos de ação residual do inseticida sobre adultos de Sitophilus spp. os insetos foram submetidos a testes em exposição aos grãos tratados após 15 dias decorridos do tratamento, 30 dias após, e, subseqüentemente, em intervalos mensais até 12 meses. Os limites de quantificação dos resíduos pelo método de análise, para os diferentes substratos variaram de 0,05 a 0,1 mg.kg-1. Os resíduos de pirimifós-metil não foram persistentes nos grãos nem em seus produtos processados, decrescendo de 4-8 vezes no período de amostragem. Eles foram maiores nos produtos processados ricos em óleos (farelo de trigo e de milho), menores nos grãos (estes semelhantes às farinhas integral e branca, e pipoca) e, ainda menores, no pão, farinha de milho e canjica. O inseticida pirimifós-metil mostrou-se bastante eficiente no controle de Sitophilus spp., no tratamento dos três tipos de grãos cereais durante todo o período de observação.The purposes of this study were to evaluate the occurence, persistence and degradation of pyrimiphos-methyl organophosphorus insecticide residues on wheat, corn and popcorn grains in and some of their processed products, as well the residual action of this insecticide for the control the Sitophilus spp. (Coleoptera, Curculionidae). Grain treatment was performed to obtain the theoretic concentration of 12 mg.Kg-1 (ppm) of pyrimiphos-methyl, which was applied at the dosage of 5 L of solution/ton of the grain. Sampling was performed at 0, 15, 30, 60, 120 and 240 days after the treatment. The samples were analyzed for residues of pyrimiphos-methyl using a residue method based on extraction with acetone, clean up by partition with acetonitrile/hexane followed by silica gel column chromatography eluted with a mixture of hexane + acetone (9:1) (v:v) solution. Residue determinations were done by the gas chromatography technique using a flame photometry detector (GLC/FPD). Total samples analyzed were 264, being 72 of cereal grains and 192 of processed products. The studies of residual action of the insecticide for the control of Sitophilus spp adults were conducted with adults and exposing the insects to treated grains 15 days after the application, 30 days, and subsequently at monthly intervals up to 12 months. The limits of quantitation of the analytical method for different substracts ranged between 0.05 to 0.1 mg.kg-1 (ppm). Pyrimiphos-methyl residues were not persistent on the grains and processed products. A decay of 4 to 8 times during the sampling period was observed. The residues found were higher in the processed products with high oil content (wheat and corn brans), lower on grains (similar to whole and white flours and popcorn) and even lower in bread, corn flour and "canjica". Pyrimiphos-methyl was very efficient for the control of Sitophilus spp on the three grain types during the entire period of observation.
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Baumgartner, Denilson. "Residual do herbicida 2,4-D no solo e sua correlação com a produtividade e os parâmetros químicos e físicos do solo." Universidade Estadual do Oeste do Parana, 2013. http://tede.unioeste.br:8080/tede/handle/tede/153.
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Previous issue date: 2013-07-05Large amounts of herbicides are used in agriculture to control weeds that pose risks to crops, resulting in increased production cost of farms. Also, if not applied properly, its use can cause resistance of spontaneous plants and result in residues in the environment, in the soil, the water or in toxicity to the crops. The objective of this research was to evaluate the residue of the 2,4-D herbicide in soil and its correlation with yield, as well as physical and chemical properties of the soil. The experiment was conducted on a farm in the city of Nova Santa Rosa, in the state of Paraná in the years 2011 and 2012. The main crops grown in the area are corn and soybeans, in rotation. Soil samples were collected to determine their physical and chemical properties and for analysis of residual 2,4-D before implementation (RI) and after application (RF) of the 2,4-D herbicide. Initially, the glyphosate herbicide was applied in a single dose (2.5 L ha-1) and then the 2,4-D herbicide was applied at two doses (1,0 and 1,5 L ha-1) with boom sprayer and, after 5 days of application, soil samples were collected for analysis of RF. After extracting the 2,4-D from the soil, high performance liquid chromatography (HPLC) was carried out to detect the active ingredient. In order to map the spontaneous plants, before and after spraying the herbicide the method of systematic sampling was used. The soybean yield for both years were also analyzed, and finally, spatial correlation of the parameters evaluated was performed. The results of RI of 2,4-D in the soil in both years, demonstrating that this is a herbicide that can remain retained in the soil over time and, depending on the soil characteristics, the preparation of the area and climatic conditions, this time can be longer. In 2011, the maximum detection of the active ingredient was 609 μg kg-1 and in 2012 was 652 μg kg-1. The RI of 2,4-D in the soil showed negative spatial correlation for chemical attributes K, organic matter and pH and for physical density, macroporosity, microporosity, total porosity and soil moisture it showed positive spatial correlation with sand and the chemical attributes Cu, Mg, Mn, P and Zn in the first year assessed. In 2012 the spatial correlation was positive with clay. The spontaneous plants type horseweed (Conyza bonariensis), did not present spatial correlation among the parameters evaluated in 2011, however, showed a positive correlation with the micropores of the soil in 2012. As residual 2,4-D in the soil and many attributes analyzed presented spatial correlation, spatial correlation among the variables analyzed proved to be an important tool to understand the influence of a parameter over the other. Both doses satisfactorily controlled the incidence of spontaneous plants. The 2,4-D showed some points with detection and other with no detection of the active ingredient in the soil, a fact that demonstrates the importance of assessing the spatial correlation of soil properties (chemical and physical) with residual herbicide in the soil, determining the influence of one attribute over the other.
Grandes quantidades de herbicidas são utilizadas na agricultura para controlar plantas espontâneas que oferecem riscos às plantações, acarretando aumento do custo de produção das propriedades agrícolas. Além disso, se não forem aplicados corretamente podem ocasionar a resistência das plantas espontâneas e resultar em residual no ambiente, quer seja no solo, na água ou na toxidez para as culturas. O objetivo desta pesquisa foi avaliar o residual do herbicida 2,4-D no solo e a sua correlação com a produtividade e os atributos químicos e físicos do solo. O experimento foi desenvolvido em uma propriedade agrícola, do município de Nova Santa Rosa/Paraná nos anos de 2011 e 2012. As principais culturas cultivadas na área são o milho e a soja em sistema de rotação. Foram realizadas amostragens de solo para determinação dos seus atributos químicos e físicos e para análise do residual de 2,4-D antes da aplicação (RI) e após a aplicação (RF) do herbicida 2,4-D. Inicialmente, foi aplicado o herbicida glifosato em dosagem única (2,5 L ha-1) e, em seguida, aplicou-se o herbicida 2,4-D em duas doses (1,0 e 1,5 L ha-1) com pulverizador de arrasto e, após 5 dias da aplicação, amostras de solo foram coletadas para análise do RF de 2,4-D. Após a extração do 2,4-D do solo foi efetuada a determinação por meio de cromatografia líquida de alto desempenho (HPLC) para detecção do ingrediente ativo. Para o mapeamento das plantas espontâneas, antes e após a pulverização do herbicida foi utilizado o método da amostragem sistemática. Também foi avaliada a produtividade da soja para ambos os anos e, por fim, foi efetuada a correlação espacial dos parâmetros avaliados. Os resultados do RI de 2,4-D no solo em ambos os anos, demonstram que este é um herbicida que pode permanecer retido no solo com o passar do tempo e, dependendo das características do solo, do preparo da área e das condições climáticas será maior ou menor. Em 2011, o valor máximo de detecção do ingrediente ativo foi de 609 μg kg-1 e em 2012 foi de 652 μg kg-1. O RI de 2,4-D no solo apresentou correlação espacial negativa para os atributos químicos K, matéria orgânica e pH e para os atributos físicos densidade do solo, macroporosidade, microporosidade, porosidade total e umidade do solo e correlação espacial positiva com a areia e com os atributos químicos Cu, Mg, Mn, P e Zn no primeiro ano avaliado. Já em 2012, a correlação espacial foi positiva com a argila. As plantas espontâneas do tipo buva (Conyza bonariensis) não apresentaram correlação espacial com os parâmetros avaliados em 2011, porém apresentaram correlação positiva com os microporos do solo em 2012. Como residual de 2,4-D no solo e muitos atributos analisados apresentaram dependência espacial, a correlação espacial entre as variáveis analisadas mostrou-se uma ferramenta importante para se conhecer a interferência de um parâmetro sobre o outro. Ambas as doses controlaram de modo satisfatório a incidência de plantas espontâneas. O 2,4-D apresentou alguns pontos com detecção e outros sem detecção do ingrediente ativo no solo, fator que demonstra a importância de avaliar a correlação espacial dos atributos do solo (químicos e físicos) com o residual do herbicida no solo, determinando a influência de um atributo sobre outro.
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Fogdal, Hanna, and Adrian Baars. "Utilization of Forest Residue through Combined Heat and Power or Biorefinery for Applications in the Swedish Transportation Sector : a comparison in efficiency, emissions, economics and end usage." Thesis, KTH, Kraft- och värmeteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215767.
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Sweden has the goal of reaching a fossil independent transportation sector by 2030. Two ways to reach the goal is to increase the use of electric vehicles or produce more biofuels. Both alternatives could be powered by forest residue, which is an underutilized resource in the country. Electricity could be produced in a biomass fired Combined Heat and Power (CHP) plant, and biofuel could be produced in a biorefinery through gasification of biomass and Fischer-Tropsch process. When located in Stockholm County, both system can also distribute heat to the district heating system. It is however important to use the biomass in an energy-efficient way. The scope of this work has been to analyze the efficiency together with environmental and economic aspects of the two systems. To assess the efficiency and environmental impact of the two systems a forest to wheel study was made of the systems where the product was studied from harvesting of forest residue to driving the vehicle. The studied functional units were: kilometers driven by vehicle, kWh of district heating, CO2-equivalents of greenhouse gases and MWh of forest residue. The system using CHP technology and electric vehicles outperformed the biorefinery system on the two first functional units. Using the same amount of forest residue more than twice as much district heating and almost twice as many driven kilometers were produced in this system. The study also showed that both systems avoids significant greenhouse gas emissions and can be part of the solution to decrease emissions from road transportation. The profitability of investing in a CHP plant or a biorefinery was calculated through the net present value method. It showed that the expected energy prices are too low for the investments to be profitable. The CHP plant investment has a net present value of -1.6 billion SEK and the biorefinery investment has a net present value of -4.6 billion SEK. Furthermore, the biorefinery investment entails higher risk due to the high investment cost and uncommercialized technology. Both systems face barriers for implementation, these barriers have been studied qualitatively.Sverige har som mål att skapa en fossiloberoende fordonsflotta till år 2030. Två vägar som pekats ut för att nå målet är att öka användningen av eldrivna fordon eller att producera mer biobränsle. Båda alternativen kan drivas av skogsavfall, en råvara som det finns gott om i Sverige. Elektricitet kan produceras av skogsavfallet i ett kraftvärmeverk, och biobränsle i ett bioraffinaderi genom användning av förgasning och Fischer-Tropschmetoden. I Stockholms län skulle båda systemen dessutom kunna producera värme till Stockholms fjärrvärmesystem. Det är dock viktigt att använda skogsavfallet på ett resurseffektivt sätt. Därför undersöker detta arbete effektiviteten av de två olika systemen tillsammans med en analys av växthusgasutsläpp och ekonomiska förutsättningar. För att kunna utvärdera effektiviteten och klimatpåverkan av de två olika systemen utfördes en ”skog-till-hjul”-analys där produkten undersöktes från ursprunget, till drivandet av ett fordon. För att utföra studien definierades fyra funktionella enheter. De funktionella enheterna var: körsträcka med bil mätt i kilometer, kWh fjärrvärmeproduktion, CO2 ekvivalenter av växthusgasutsläpp och MWh skogsavfall. Studien visade att systemet där skogsavfallet används i ett kraftvärmeverk för att producera elektricitet och ladda elbilar hade bättre resultat i de två första funktionella enheterna. Systemet producerade nästan dubbelt så lång körsträcka och mer än dubbelt så mycket fjärrvärme som systemet där skogsavfallet används i ett bioraffinaderi och biobränslet används i dieselbilar. Studien visade även att båda system kan bidra till att sänka växthusgasutsläppen från transportsektorn. Lönsamheten att investera i ett kraftvärmeverk eller bioraffinaderi beräknades med nuvärdesmetoden. Studien visade att de förväntade framtida energipriserna är för låga för att investeringarna ska bli lönsamma. Kraftvärmeanläggningen hade ett nuvärde på -1.6 miljarder kronor, och bioraffinaderiet ett nuvärde på -4.6 miljarder kronor. Dessutom ansågs investeringen i ett bioraffinaderi vara en hög risk på grund av den höga investeringskostnaden och att tekniken idag inte är kommersialiserad. Det finns även en rad andra barriär för att genomföra de två olika systemen, dessa barriärer har studerats kvalitativt i arbetet.
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Souza, Antonio Pancracio de. "Atividade inseticida e modo de ação de extratos de meliáceas sobre Bemisia tabaci (Genn., 1889) Biótipo B." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-04082004-135541/.
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Foram conduzidos experimentos com o objetivo de avaliar a bioatividade e o modo de ação de extratos aquosos e orgânicos de ramos de Trichilia pallida Swartz e extratos aquosos de sementes de nim, Azadirachta indica A. Juss, em relação a ninfas e ovos da mosca-branca Bemisia tabaci (Genn.) biótipo B. Inicialmente, verificou-se que o extrato aquoso de sementes de nim apresenta ação inseticida sobre ninfas de mosca-branca pelas vias translaminar, sistêmica e de contato, nas concentrações de 1; 0,5 e 0,3% (p/v), respectivamente. Em seguida, na comparação entre os extratos metanólico, etanólico, clorofórmico e hexânico de ramos de T. pallida, na concentração de 5% (p/v), foi selecionado o extrato clorofórmico como mais eficiente sobre ninfas de mosca-branca. Esse extrato foi comparado com os extratos aquosos de sementes de nim e de ramos de T. pallida sobre as ninfas quanto aos três tipos de ação nas respectivas concentrações determinadas no experimento. Apenas o extrato de nim provocou mortalidade ninfal pelas três vias testadas. Em relação à fase de ovo, constatou-se que a sua idade não afeta a ação ovicida do extrato aquoso de sementes de nim. Na comparação da ação translaminar e sistêmica dos extratos aquoso e clorofórmico de ramos de T. pallida e aquoso de sementes de nim, a 3% (p/v), sobre os ovos de mosca-branca, verificou-se que apenas o extrato de nim tem efeito ovicida.The objective of this research was to determinate the bioactivity and the action means of aqueous and organic extracts of Trichilia pallida Swartz twigs, and the aqueous extracts of neem seeds, Azadiracta indica A. Juss, on nymphs and eggs of silverleaf whitefly. Initially, it was observed that aqueous extracts of neem seeds caused insecticidal activity on the nymphs by translaminar (1%), systemic (0,5%) and topical action (0,3%). After, in the comparison of metanolic, etanolic, chloroformic, and hexanic T. pallida twig extracts at the concentrations of 5%, the chloroformic extract was more efficient on the nymphs. This extract was compared with aqueous extracts of neem seeds, and the T. pallida twigs, by three means (translaminar, systemic and topical action) at concentrations previously determinated. Just the neem extract caused nymphal mortality for three means. In relation to the phase of eggs, it was verified that the age did not affect the ovicidal action of aqueous extract of neem seeds. In the comparison of translaminar and sistemic action of aqueous and chloroformic extracts of T. pallida twigs and aqueous extracts of neem seeds (3%) on eggs of the insect, just the neem extract showed ovicidal activity.
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Penick, William Frazier. "Influence of Transplanter Modification and Previous Crop on the Production of No-Till Dark Tobacco." TopSCHOLAR®, 2013. http://digitalcommons.wku.edu/theses/1257.
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Dark tobacco (Nicotiana tabacum L.) has historically been produced usingconventional tillage practices. Soil is cultivated multiple times throughout a growing season leading to an increased incidence of soil erosion. No-till systems have been growing in popularity with the advent of new technology that has enabled the practice to be performed effectively and efficiently. With the recent expansion of no-till practices throughout the agricultural community, many crops have had success in producing comparable yields while reducing input costs and saving soil resources. For this experiment, a traditional tobacco transplanter was modified for use in a no-till environment. All modifications were fabricated without using specialty tools and made possible to be removed if desired or necessary. Frame extensions were designed and built to accommodate row cleaners and coulters. Tillage shanks were also added to aid in optimal furrow formation. Double-disc opening shoes replaced the original round point shoes and the curved edges of the rear drive wheels were removed, creating a flat surface to increase soil contact. Experimental no-till plots in fescue sod and soybean chaff residues were conducted alongside conventional tillage plots at the Western Kentucky University Agricultural Research and Education Complex in summer 2011. Five treatments, one conventionally tilled (Conv) and four no-till, were replicated three times within a randomized complete block design and used to determine the efficacy of transplanter modifications (consistency of depth, furrow closure, observed plant damage), survival of the transplants, and the amount of residue displacement. The four no-till treatments utilized different combinations including: coulter, row cleaner and shank (CRS), row cleaner and shank (RS), coulter and shank (CS), and shank only (S). These treatments demonstrated the functionality of each combination in comparison to conventional treatments. No treatment performed equally well in both residue locations. Plots in fescue residue utilizing a combination of coulter, row cleaner, shank (CRS), exhibited the lowest amount of root exposure, highest survival rate, and comparable cured weight when compared to conventionally tilled treatments. In soybean residue plots, the treatment operating with row cleaners and shanks (RS) had equivalent amounts of furrow closure to conventionally tilled plots. Pairing specific modification combinations with previous crop residue can provide furrow closure, transplant survival, and cured yield equivalent to conventionally tilled dark tobacco.
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Franco, André Andrade. "Resíduos de deltametrina, aplicada em diferentes formulações, em compartimentos da cultura do pepino (Cucumis sativus L.) tutorado e ação do inseticida no controle da broca-das-cucurbitáceas Diaphania nitidalis (Cramer, 1782) (Lepidoptera: Crambidae)." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-11112004-140048/.
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O desenvolvimento da agricultura, a modernização dos meios dos cultivos, buscando atender a um mercado exigente, tem-se baseado no uso de insumos agrícolas para garantir a produção de alta qualidade e de quantidade. Tais culturas demandam o uso de pesticidas, cujos resíduos, principalmente em hortaliças e frutas, são motivo de preocupação com a saúde dos consumidores e de operários que necessitam retornar às culturas tratadas com esses agrotóxicos. Os objetivos deste estudo foram: a) estudar o comportamento dos resíduos de deltametrina, de diferentes formulações, em frutos, folhas e solo; b) avaliar os resíduos deslocáveis do inseticida nas folhas, como ponto de partida para estudos de exposição ocupacional; c) correlacionar os teores de deltametrina nos frutos com o controle da broca-das-cucurbitáceas e d) correlacionar os resíduos nos frutos com o limite máximo de resíduo (LMR) e o intervalo de segurança (período de carência) estabelecidos pela legislação. Os tratamentos foram: a) testemunha; b) três aplicações da formulação em concentrado emulsionável Decis 25 CE na dosagem de 30 mL p.c.100 L-1 de água (0,75 g i.a. deltametrina.100 L-1 de água); c) três aplicações da formulação em concentrado emulsionável Decis Ultra 100 CE na dosagem de 7,5 mL p.c.100 L-1 de água (0,75 g i.a. deltametrina.100 L-1 de água); e d) três aplicações da formulação em suspensão concentrada Decis 200 SC na dosagem de 3,75 mL de p.c.100 L-1 de água (0,75 g i.a. deltametrina 100 L-1 de água). As amostras de fruto e de solo foram colhidas a (-1); zero; 1; 3; 5 e 7 dias após a última aplicação; as amostras de folhas e as de para estudos de resíduos deslocáveis nestas foram tomadas a (-1); zero; 1; 3; 5; 7 e 14 dias. O método analítico constou da extração dos resíduos de deltametrina de acetato de etila, limpeza dos extratos por técnica de cromatografia de permeação em gel (GPC), com eluição feita com uma mistura de acetato de etila/ciclohexano. A determinação quantitativa por cromatografia de gás. Para a avaliação da eficiência do inseticida, foram feitas seis levantamentos de infestação, determinando-se a porcentagem de frutos brocados. Os resultados indicaram que os resíduos de deltametrina no fruto, embora em baixos níveis, encontravam-se acima do LMR (0,03 mg.kg-1), mesmo um dia após o término do intervalo de segurança (2 dias) para as formulações do inseticida. Nas folhas, os resíduos resultantes das aplicações da formulação SC foram sempre maiores do que ambas CE (10-20 vezes), sendo de 15-80 vezes mais altas do que nos frutos. No solo, os resíduos foram também baixos (0,01-0,05 mg.kg-1), e semelhantes nas três formulações, entretanto, com baixa dissipação. Os resíduos deslocáveis de deltametrina nas folhas foram muito elevados quando de aplicações em SC, comparadas com as formulações CE (4-20 vezes), com valores de meias-vida de 2,8; 3,8 e 32,2 dias, respectivamente para as formulações Decis 25 CE, Decis Ultra 100 CE e Decis 200 SC. O inseticida, nas formulações em que foi aplicado, foi eficiente no controle da praga durante todo o período de avaliação.The agriculture development, the modernization of cultivation means, trying to meet a demanding market, has been based on the use of agricultural supplies to assure a high quality and quantity production. Such crops demand the use of pesticides, whose residues, especially in fruit and vegetable production, raise worries about the consumers health and of the workers who need to return to the treated crop with these pesticides. The objectives of this study were: a) to study the behavior of deltamethrin residues applied in different formulations in fruits, leaves and soil; b) to evaluate the dislodgeable residues of the insecticide in leaves, as a starting point for occupational exposure studies; c) to correlate deltamethrin concentration in fruit with the pickleworm control and d) to correlate residues in fruit with the maximum residue level (MRL) and the safety interval established by the legislation. The treatments were: a) control ; b) three applications of the emulsifiable concentrate formulation Decis 25 CE.100-1 at the dosage of 30 mL of c.p.100 L-1 water (0.75 g a.i. deltamethrin.100L-1 water); c) three applications of the emulsifiable formulation of Decis Ultra 100 CE at the dosage of 7.5 mL of p.c.100 L-1 water (0.75 g a.i. deltamethrin.100. L-1 water) and d) three applications of the concentrate suspension formulation Decis 200 SC at the dosage of 3.75 mL of c.p.100.L-1 water (0.75 g a.i. deltamethrin 100L-1 water). The fruit and soil samples were taken at (-1); zero; 1; 3; 5 and 7 days after the last application; leaf samples and also those for the studies of dislodgeable residues on them were collected at (-1); zero; 1; 3; 5; 7 and 14 days after the last application. The analytical method consisted of the extraction of deltamethrin residues in ethyl acetate, clean-up of the extracts by gel permeation chromatography (GPC), with elutition made with a mixture of ethyl acetate/cyclohexane. The quantitative determination was made by gas chromatograph. To evaluate the insecticide efficacy six infestation surveys were carried out, based on the percentage of infested fruit . The results indicate that the deltamethrin residues in fruit, though in low levels, were found higher than the MRL (0.03 mg.kg-1), for the three insecticide formulations, even a day after the end of the safety interval (2 days). In the leaves the resulting residues of the applications of SC formulation were always bigger than both CE (10-20 times), being 15-80 times higher in the fruits. In the soil, the residues were also low (0.01-0.05 mg kg-1), and similar in the three formulations, however with low dissipation. The dislodgeable residues of deltamethrin in leaves were higher in SC as compared to both CE (4-20 times), with half-life values of 2.8; 3.8 and 32.2 days, respectively for the formulation Decis 25 CE, Decis Ultra 100 CE and Decis 200 SC. The insecticide in the formulations applied was efficient in the pest control during the whole evaluation period.
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Cochran, Michele A. "Effect of land application of fluidized-bed combustion residue on soil and plant characteristics of reclaimed surface-mined pastures, performance and mineral status of grazing steers and nutrient balance by sheep fed the forage." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43389.
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Meira, Ana Paula Gasques. "Ingestão de resíduos de agrotóxicos potencialmente contidos na dieta habitual de escolares." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11141/tde-10112016-105057/.
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O uso de agrotóxicos no cultivo de alimentos é cada vez mais intenso e o Brasil é o país que mais utiliza esse recurso na agricultura. Esses compostos são potencialmente prejudiciais ao homem, podendo ocasionar diversos efeitos adversos na saúde, situação que contradiz o conceito de Segurança Alimentar e Nutricional. O objetivo geral desta pesquisa foi estimar a Ingestão Diária Máxima Teórica (IDMT) dos agrotóxicos potencialmente contidos na dieta habitual dos escolares e comparar com os parâmetros de ingestão estabelecidos pelos órgãos reguladores. Os dados de consumo alimentar e antropométricos utilizados são provenientes do conjunto de dados originais (n = 341) obtidos junto a amostra de escolares matriculados nas unidades públicas de ensino do município de Guariba (São Paulo), no ano de 2013. Para a análise de ingestão dos agrotóxicos foi utilizada a média de consumo alimentar dos escolares, obtida por meio de dois recordatórios de 24 horas. A partir das adequações na padronização das terminologias dos alimentos ou preparações, conversão das medidas caseiras em gramas de alimento e desmembramento das preparações consumidas, foi construído um banco de dados de consumo. Outros bancos de dados construídos foram das aferições antropométricas dos alunos e dos parâmetros relativos ao Limite Máximo de Resíduos (LMR) e Ingestão Diária Aceitável (IDA). Foram utilizados dados de Limite Máximo de Resíduos (LMR) adotados pela Agência Nacional de Vigilância Sanitária (ANVISA) e Codex Alimentarius. A Ingestão Diária Aceitável (IDA) obteve-se de quatro órgãos (Agência Nacional de Vigilância Sanitária (ANVISA), Codex Alimentarius, Environmental Protection Agency (EPA) e governo da Austrália). Os resultados mostraram que os valores medianos de ingestão (estimada) de nove, do total de 272 agrotóxicos, excederam a Ingestão Diária Aceitável (IDA) estabelecida pela ANVISA. Adotandose os parâmetros dos demais órgãos, verifica-se que cinco agrotóxicos excederam os valores da agência EPA, quatro, o Codex Alimentarius e quinze o governo da Austrália. Destaca-se também que 58 agrotóxicos tiveram ingestão máxima que supera os limites estabelecidos pela ANVISA. Entre os nove agrotóxicos, cujos valores da mediana de ingestão ultrapassou o limite IDA da ANVISA, mais de 50% são classificados como muito tóxicos. Foi possível observar ainda a quantidade expressiva de agrotóxicos sem IDA estabelecido.The use of pesticides in the agriculture production is becoming more intense. Brazil is the country that uses this resource in agriculture. These compounds are potentially harmful to humans and can cause many adverse health effects, a situation which contradicts the concept of food and nutrition security. The overall objective of this research was to estimate the Theoretical Maximum Daily Intake (TMDI) of pesticides potentially contained in the usual diet of students and compare with the intake parameters established by regulatory agencies. The food intake and anthropometric data used are from the set of original data (n = 341) obtained from the sample of schoolchildren enrolled in the public education facilities in the city of Guariba (São Paulo), in 2013. For the analysis of consumption of pesticides used was the average food consumption of school, obtained by means of two reminders 24 hours. From adjustments in standardization of terminologies of food or preparation, conversion of household measures in grams of food consumed and dismemberment of preparations, has built a consumer database. Other databases were built of anthropometric measurements of students and parameters relating to the Maximum Residue Limits (MRLs) and Acceptable Daily Intake (ADI). Limit data were used Maximum Residue Levels (MRLs) adopted by the National Health Surveillance Agency (ANVISA) and Codex Alimentarius. The Acceptable Daily Intake (ADI) obtained from four agencies (National Health Surveillance Agency (ANVISA), Codex Alimentarius, Environmental Protection Agency (EPA) and the Australian government). The results showed mean intake values (estimated) nine compounds, the total of 272 pesticides, exceeded the Acceptable Daily Intake (ADI) established by ANVISA. Admitting parameters of other agencies, there are five pesticides that exceeded the EPA agency values, four compounds exceed the Codex Alimentarius and fifteen exceed the government of Australia values. It is noteworthy that 58 pesticides had maximum intake that exceeds the limits established by ANVISA. Among the nine pesticides whose intake median values exceeds the IDA limit ANVISA, more than 50% are classified as very toxic. It was also possible to observe the significant amount of pesticides without IDA established.