Orientadores: Telma Teixeira Franco, Gustavo Paim Valença / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-15T16:00:27Z (GMT). No. of bitstreams: 1 Ayres_BiancaMairaTeixeira_M.pdf: 702836 bytes, checksum: 9d7d2a539cf470dfe7892bf64c17518d (MD5) Previous issue date: 2010 / Resumo: O presente trabalho estudou as melhores condições para a produção de monoacrilato de frutose a partir da esterificação de ácido acrílico com D-frutose catalisada pela lípase comercial de Cândida antárctica (Novozyme 435). O interesse na produção deste éster se dá devido à promissora propriedade absorvente de água do polímero a ser produzido, com diferentes aplicações possíveis. Esterificações enzimáticas são reações de equilíbrio cujo subproduto é a água. A presença desta tem de ser controlada para possibilitar atividade enzimática e evitar a hidrólise dos ésteres. A adição de peneira molecular 3 Á ao sistema foi investigada para remoção da água produzida e favorecimento do deslocamento do equilíbrio para síntese dos ésteres. A produção exclusiva de monoéster foi observada quando a razão molar frutose:ácido acrílico de 1:3, 55 °C, agitação de 200 rpm e 20 mg mL-1 de lípase foram empregadas. Quando a razão molar foi aumentada para 1:5 a conversão de frutose aumentou, mas o equilíbrio foi deslocado para a produção de di- e triéster de frutose. A adição de 3 g de peneira molecular em 25 mL de sistema reacional resultou na produção de 49.5 mM de monoacrilato de frutose com 84 % de conversão da frutose inicial e 41 % da conversão de ácido acrílico após 24 h de reação. Devido à inexistência de padrões de acrilatos de frutose no mercado, um método para quantificação destes por fatores de resposta de CLAE foi desenvolvido baseado nos dados cinéticos da reação / Abstract: The optimal conditions for the enzymatic production of fructose acrylates were studied. Fructose to acrylic acid molar ratio, the amount of immobilized lipase Candida antarctica and the influence of molecular sieve in the reaction media were studied. The results of these variables in converting sugar were monitored. Enzymatic esterifications are equilibrium reactions whose subproduct is water. The presence of this must be controlled to allow enzymatic activity of the lipase and to avoid hydrolysis of esters. The addition of molecular sieve 3 A to the system was investigated to remove of produced water and to shift the equilibrium to the synthesis of ester. The exclusive production of monoester was observed when the molar ratio of fructose: acrylic acid of 1:3, 55 °C, 200 rpm and 20 mg ml-1 of immobilized lipase was employed. When the molar ratio is increased the conversion of fructose increases, but the equilibrium was shifted to the production of di- and triester. The addition of 3 g of molecular sieve resulted in the production of 49.5 mM of fructose monoacrylates, 84 % conversion of the initial fructose and 41 % conversion of acrylic acid after 24 hours of reaction. Since sugar acrylates are not available, it were obtained the concentrations of esters from the determination of response factors of each ester by HPLC-RI based on linear regression / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

O conhecimento da movimentação da água no solo é de grande importância para a agricultura, pois a água é um dos fatores que mais influenciam no rendimento das culturas. Das várias técnicas utilizadas para o monitoramento do conteúdo de água no solo, a reflectometria no domínio do tempo (TDR) vem sendo bastante difundida entre os pesquisadores por apresentar inúmeras vantagens, dentre as quais a mensuração em tempo real e a possibilidade de leituras automatizadas. Com o objetivo de avaliar a movimentação da água num perfil de um Latossolo vermelho-amarelo, conduziu-se um experimento obtendo-se os valores de umidade do solo e condutividade elétrica através das leituras de um equipamento de TDR com sondas instaladas em uma trincheira em diversas profundidades (0,10 m a 0,60 m) e com diferentes taxas de aplicação (2, 4 e 8 L.h-1) de solução em intervalos de 1 hora, via irrigação por gotejamento. A partir dos resultados obtidos, pôde concluir-se que diferentes vazões de aplicação determinam características particulares de formação do bulbo molhado e da movimentação da solução no solo. Para as condições de solo e de acordo com o volume e a frequência utilizada durante este experimento, recomenda-se a aplicação de pequenas quantidades de solução em intervalos mais frequentes para reduzir a perda por percolação de água e solutos. / The knowledge of the water distribution in soil has great importance to the agriculture because of the crop yield the cultures income has a direct influence by the water. There are many techniques used to monity soil moisture, and the time domain reflectometry (TDR), has a satisfactory application among the researches because the advantages, allow the real time measurements can be automatized and the automatized. With the objective to appraise the water distribution and electrical conductivity in a Red-yellow Latosol profile, the experiment was conducted measuring soil moisture through the TDR equipment reading with probes fixed in a trench in various depths (0,10 m to 0,60 m) and with different applications rates of solution (2,4 and 8 L.h-1) , with one hour interval by dripping irrigation. The results allowed us to that the different sewages applications determinate the particular characteristics of the wet bulb arrangement and the water soil distribution. For the soil conditions and according to the volume and frequency used during this experiment, it is recommended to apply of small quantities of a solution at more frequent intervals to reduce the loss by percolation of water and solute.

Made available in DSpace on 2016-08-19T12:56:46Z (GMT). No. of bitstreams: 1 DISSERTACAO JOSE RODRIGUES DELFINO.pdf: 1176188 bytes, checksum: f5f37c5f597e0393d23bfcfc6e7abeec (MD5) Previous issue date: 2014-07-10 / FUNDAÇÃO DE AMPARO À PESQUISA E AO DESENVOLVIMENTO CIENTIFICO E TECNOLÓGICO DO MARANHÃO / The moisture in biodiesel is an important parameter that should be monitored to ensure the final quality of the biofuel. We have developed a new and alternative method for determination of this parameter in biodiesel by electrochemical impedance spectroscopy. The method is based on the variation of the resistance to charge transfer medium depending on the amount of water in the biodiesel as a treatment of the sample using a simple dilution of samples of biodiesel in acetonitrile. Operating parameters optimized for the quantification of water content by electrochemical impedance were: 10 mV amplitude, time OCP = 20s, frequency range 10⁶ to 10ˉ¹ Hz and points per frequency decade = 10. In optimized conditions was obtained a good linear correlation between the resistivity of the medium and the water content, which allowed the determination of this parameter on samples of biodiesel. A substantial change in charge transfer resistance was observed with the additions of water in the sample solution, confirming the viability of the analytical method under study. The procedure was applied to samples of biodiesel and statistically validated, the results were considered satisfactory. The accuracy of the method was checked by recovery tests (ranging from 96.15% to 102.69%), and also application of Student's t-test, with concordant results, as there was no significant difference between the averages obtained by this method (Sample1 = 460.6 mg kgˉ¹ and Sample2 = 512.7 mg kgˉ¹) and the average obtained by the official method, Norma ANP 14/12 (Sample1 = 486.8 mg kgˉ¹ and Sample2 = 540,6 mg kgˉ¹) for a confidence level of 95%. The precision showed a coefficient of variation less than 5%. Average detection limits of 1.77 mg kgˉ¹for the samples proved the good sensitivity (10.1 Ω/cm2.Kg.mgˉ¹) of the proposed method. The values obtained for water content of the samples were between 270.3 ± 3.4 mg kgˉ¹ and 540.6 ± 12.9 mg kgˉ¹ for the water content in the samples of biodiesel certified by the program interlaboratory ANP. / A umidade em biodiesel é um importante parâmetro que deve ser monitorado para garantia da qualidade final do biocombustível. Neste trabalho foi desenvolvido um novo e alternativo método para determinação desse parâmetro em biodiesel por espectroscopia de impedância eletroquímica. O método baseia-se na variação da resistência a transferência de carga do meio em função da quantidade de água no biodiesel, usando como tratamento da amostra uma simples diluição das amostras de biodiesel em acetonitrila. Os parâmetros operacionais otimizados para a quantificação do teor de água por impedância eletroquímica foram: amplitude 10 mV, tempo em potencial de circuito aberto = 20s, faixa de frequência 10⁶ a 10ˉ¹ Hz e pontos por década = 10. Em condições otimizadas obteve-se uma boa correlação linear entre a resistividade do meio e o teor de água, a qual permitiu a determinação desse parâmetro nas amostras de biodiesel. Uma sensível variação da resistência de transferência de carga foi verificada com as adições de água na solução da amostra, confirmando a viabilidade analítica do método em estudo. O procedimento foi aplicado a amostras de biodiesel e validado estatisticamente, cujos resultados foram considerados satisfatórios. A exatidão do método foi verificada através de testes de recuperação (que variaram entre 96,15% e 102,69%), e também com aplicação do Teste-t de Student, com resultados concordantes, pois não houve diferença significativa entre as medias obtidas pelo presente método (Amostra1 = 460,6 mg Kgˉ¹ e Amostra2 = 512,7 mg Kgˉ¹) e a média obtida pelo método oficial, Norma ANP 14/12 (Amostra1 = 486,8 mg Kgˉ¹ e Amostra2 = 540,6 mg Kgˉ¹) para um nível de confiança de 95%. A precisão apresentou um coeficiente de variação inferior a 5%. Limites de detecção médio de 1,77 mg Kgˉ¹ para as amostras analisadas, comprovaram a boa sensibilidade (10,1 Ω/cm2.Kg.mgˉ¹) do método proposto. Os valores de teor de água obtidos para as amostras analisadas situaram-se entre 270,3 ± 3,4 mg Kgˉ¹ e 540,6±12,9 mg Kgˉ¹ para o teor de água nas amostras de biodiesel certificadas pelo programa interlaboratorial da ANP.

Made available in DSpace on 2014-08-20T13:59:16Z (GMT). No. of bitstreams: 1 dissertacao_leticia_rickes.pdf: 3102016 bytes, checksum: 3dc865cfac99406b5f91e8f7e31d2c1d (MD5) Previous issue date: 2012-02-28 / The translocation of water and carbohydrates in plant tissues temperate fruit still creates doubts in the scientific field and knows that it is a factor to overcome dormancy, because to be budburst is needed imports of soluble sugars, the which are derived from starch conversion adjacent tissues. This work aimed to evaluate biweekly water content (WC), content of total soluble sugars (TSS), sucrose content and starch during the winter period (June to September) in tissues of pear cvs. Housui and Packham's and peach cvs. Eldorado and Jubileu of the orchards belonging to the Agricultural Center of Palma UFPel. During data collection, four branches were collected from each cultivar were divided into three positions (basal, median, apical) to assess where the WC, they were divided in two tissues: bark and wood. It was found in pear cultivars in both tissue and skin tissue in the wood, do not show large differences in the dynamics of WC in the three positions studied during the winter period. However, peach WC on the wood was examined in more than one shell in the three positions of the branch. The observed increase in WC can be a physiological marker to break dormancy. This different behavior can be attributed to the accumulation of cold. Regarding the dynamics of carbohydrate species in the study behaved differently. In peach there was a significant increase in carbohydrate content in the apical position around the time of shooting, not unlike what was observed in the case of the pear. The lack of cold and thermal fluctuations directly affect the activity of hydrolytic enzymes, which explains the lack of starch degradation in the tissues of the pear. The two species have different requirements in relation to the accumulation of cold, explaining the different behavior in the dynamics of water and carbohydrates in the winter rest period. / A translocação de água e carboidratos nos tecidos de plantas frutíferas de clima temperado ainda gera dúvidas no campo científico e sabe-se que é um fator determinante para superação da dormência, pois para haver brotação das gemas é necessário que haja importação de açúcares solúveis, aos quais são provenientes da conversão do amido nos tecidos adjacentes. Este trabalho teve como objetivo avaliar quinzenalmente o conteúdo de água (CA), conteúdo de açúcares solúveis totais (AST), conteúdo de sacarose e amido, durante o período hibernal (junho à setembro) em tecidos de pereira cvs. Housui e Packham´s e pessegueiro cvs. Jubileu e Eldorado dos pomares pertencentes ao Centro Agropecuário da Palma da UFPel. A cada coleta foram coletados quatro ramos de cada cultivar e divididos em três posições (basal, mediana, apical) onde para avaliação do CA, estes foram divididos em dois tecidos: casca e lenho. Foi verificado nas cultivares de pereira tanto no tecido da casca quanto no tecido do lenho, não apresentar grandes diferenças na dinâmica do CA nas três posições avaliadas durante o período hibernal. No entanto, no pessegueiro o CA no lenho foi superior a aquele analisado na casca nas três posições do ramo. O aumento do CA verificado pode ser um marcador fisiológico para superação da dormência. Este comportamento diferenciado pode ser atribuído ao acúmulo de frio. Em relação à dinâmica dos carboidratos, as espécies do estudo comportaram-se de maneira diferenciada. No pessegueiro houve um aumento significativo no conteúdo de carboidratos na posição apical próximo ao período de brotação, o que contrariamente não foi verificado no caso da pereira. A falta de frio e as oscilações térmicas afetam diretamente a atividade das enzimas hidrolíticas, ao qual explica a falta de degradação do amido nos tecidos da pereira. As duas espécies apresentam exigências diferenciadas em relação ao acúmulo de frio, justificando o comportamento diferenciado na dinâmica da água e carboidratos no período de repouso hibernal.

Traceability can be considered one of the most important operation in the agro industry at the moment, revealing itself even more in the creation of a new culture involving the primary sector, demanding that producers and businesses aggregate new techniques and knowledge which are able to guarantee the survival, growth, profit and competitiveness of the poultry sector. The total water content of some poultry cuts has been the target of questioning from importers. These state that the production process is being fraudulent, where the absorption of water in the preparation process is being excessive. Facing this scenery and many uncertainties, the objectives of this paper was: to present a traceability tool model destined for the Brazilian aviculture in integrated system, aiming to evaluate the quality of salty poultry cuts on total water content. As methodology, we strived to learn about what the Brazilian companies are thinking about traceability, its necessities and difficulties. The accompaniment of the production processes and contact with authorities and technicians served in the development of a doable and adequate traceability program for Brazilian aviculture. To determine total water content in poultry cuts, a relationship between moisture and protein U/P in refrigerated, frozen, salty refrigerated and salty frozen cuts was done, before and after the chiller. The essential information for traceability in poultry segment, in integrated system, must be organized in order to assure that every production steps happens under controlled conditions and be able to witness. The present information in the product packaging must be sufficient to link the product to primary sector and controls done in different processes during its production. Research done in Brazilian industries showed that they are aware of necessity to adopt traceability, but they are confused about the benefits. The different treatments show the tendency of increase water content in poultry cuts after the refrigeration of the carcasses in tanks, which is natural, even the treatments are in agreement to the standards. The variance analysis (ANOVA) did not show significant difference (p<0,05), for differents treatments before end after chiller. For traceability, the minimum information necessary are: suppliers, linage, group, breeder and broiler, farm name, date of egg posture, date of egg eclosion, feed type, production date, formula number, date and time of slaughter, federal inspection number, order number, product and lot number. The extra information for different traceability objectives are maintained filed in the process. Government and industries union support are necessary to define the kind of traceability in aviculture. The manual salting and fast freezing of product in impermeable packagings do not exert influence over the total water content in poultry cuts. For this product, controls must be done during the carcass passing through the chiller. / Pode-se considerar que a rastreablidade apresenta-se como uma operação das mais importantes da agroindústria no momento, destacando-se ainda mais na criação de uma nova cultura envolvendo o setor primário, exigindo que produtores e empresas agreguem novos conhecimentos e técnicas, capazes de garantir a sobrevivência, crescimento, lucratividade e competitividade do setor avícola. O teor total de água de determinados cortes de aves de corte tem sido alvo de questionamento de importadores. Estes afirmam que o processo de produção está sendo fraudulento, onde a absorção de água no decurso da preparação está sendo excessiva. Diante deste cenário e tantas incertezas, o objetivo deste trabalho foi: Apresentar uma proposta da ferramenta rastreabilidade para a avicultura brasileira em sistema integrado, visando avaliar a qualidade dos cortes de frango salgados congelados quanto ao teor de água total. Como metodologia buscou-se saber o que as empresas brasileiras estão pensando sobre a rastreabilidade, suas necessidades e dificuldades. O acompanhamento dos processos de produção e contato com técnicos e autoridades, serviu para o desenvolvimento de um programa de rastreabilidade factível e adequado a avicultura brasileira. Para rastrear o teor de água total em cortes de frango, foi feita a relação entre a umidade e proteína U/P de cortes resfriados, congelado, resfriado salgado e congelado salgado, antes e após o chiller. As informações necessárias à rastreabilidade no segmento aves, em sistema integrado, devem ser organizadas de modo a assegurar que todas as fases de produção aconteçam sob condições controladas e possíveis de evidenciar. As informações presentes na embalagem de um produto devem ser suficientes para ligar o produto ao setor primário e os controles realizados nos diferentes processos durante sua produção. Pesquisa realizada junto às indústrias brasileiras, mostrou que elas têm ciência da necessidade de adoção da rastreabilidade, porém estão confusas em relação ao seu benefício. Os diferentes tratamentos mostram a tendência do aumento do teor de água nos cortes depois do resfriamento de carcaças em tanques, o que é natural, embora estes estejam em acordo com os padrões. A análise de variância (ANOVA) não mostrou diferença significativa (p<0,05), para os diferentes tratamentos antes e após o chiller. Para a rastreabilidade as informações mínimas necessárias são: fornecedores, linhagem, grupo, nome da granja, aviário, data de postura dos ovos, data de eclosão, nome do parceiro, tipo de ração, data da produção, número da fórmula, data e hora de abate, número do SIF, número do pedido, nome do produto e lote. As demais informações para os diferentes objetivos da rastreabilidade, são mantidos arquivados no processo. É necessário apoio do governo e união das indústrias para definir a forma de rastreabilidade no setor avícola. A salga manual e congelamento rápido do produto, em embalagem impermeável, não exercem influência sobre o teor de água total nos cortes de frango. Para este produto o controle deve ser realizado durante a passagem da carcaça pelo chiller.

A pavement construction designed to cope with the different type of traffic loads; it is exposed to and at the same time it can resist the effect of the climate. A road structure consists of sub- and superstructure which is divided by a boundary known as terrace. During the construction of unbound layers (base course and sub-base course) in the superstructure, it is always ensured that the material meet the requirements for bearing capacity and the degree of compaction. These parameters are controlled by various laboratory tests and control methods. To obtain increased knowledge of the material and improve the quality of the compaction in the field, it is necessary to perform laboratory tests in order to determine material properties. A base course material 0/ 32 mm limestone from Gotland (Hejdeby) was investigated in this study. To determine properties of the material various laboratory tests such as proctor compaction test, Micro-Deval, Los Angeles, and grain distribution curve are conducted. To investigate how grain size distribution affects technical properties of the material, the 0/32 mm material was modified with two different samples; grain size distribution of 2/32 mm excluding superior material content, and 0+/32 mm with enhanced superior material content. The purpose of this study was to examine changes in material behavior during proctor compaction. Two aspects of changes in material behavior were emphasized in this study; the optimal water content and maximum dry density, as well as changes of both. As a reference for the limestone features, a traditional 0/32 mm tonalite material (granite) from Vällstaverket was used relating to proctor investigation. Material's resistance to abrasion and fragmentation was investigated by two methods: Micro-Deval and Los Angeles. The results were compared with other rock materials. Furthermore the bearing capacity of the material was verified by examination of the Young's modulus and degree of compaction, as well as properties of water content and dry density, at three trial areas on Gotland. This is performed with various methods such as static plate loading test, light weight deflectometer, density gauge/SDG200, and water/sand volume meter measurement test. By comparing results from different methods of measurement, it may indicate a relationship between these. Test area 3 consists of two smaller test areas which have different water content. The bearing capacity (Young's modulus) and the degree of compaction were measured after each roller passage. Different relationships were obtained between the amount of roller overpass, with Young's modulus of material; as well as degree of compaction. It was found in this study that limestone from Gotland (Hejdeby) maintain its position as construction material for the unbound layers of the road. The result from static plate load which indicated high E V2 values (Young's modulus) was obtained from the field, and it suggests that a fine bearing capacity can be achieved in the use of limestone.

<div>Drought is the leading cause of crop loss globally. Breeding for drought tolerance is difficult due to the polygenetic nature of the trait and low heritability of yield under drought. Plant relative water content is a secondary trait that may advance drought breeding programs.</div><div><br></div><div>The LeafSpec, a newly developed hyperspectral leaf scanner, was used to test the hypothesis that distribution of hyperspectral information across the leaf can be used to improve prediction of leaf relative water content. Data was collected across two experiments from five different maize genotypes representing temperate and tropical hybrids with varying levels of drought tolerance and inbreds with varying stomatal densities. The hyperspectral intensity averaged across the entire leaf was used to predict relative water content with an R2Prediction of 0.7989. Model performance was tested using additional predictors that quantify:</div><div><br></div><div>• Spectral information from multiple regions in the leaf (e.g. base, middle, tip).</div><div>• Spectral information from regions segmented by tissue type.</div><div>• The distribution of hyperspectral intensity in a cross section parallel to the midrib or in a cross-section perpendicular to the midrib.</div><div>• A contour pattern of hyperspectral intensity from the outside edge of the leaf to the midrib.</div><div>• Texture features extracted from each wavelength.</div><div><br></div><div>The mean spectrum model outperformed previously reported results, potentially due to the elimination of sources of noise and higher quality data produced by the LeafSpec. None of the models with expanded feature sets outperformed the mean spectrum model at a statistically significant level. The hyperspectral signal from the green tissue a third of the way from the base of the leaf and half way between the midrib and edge was the most correlated with relative water content. Models without midrib and vein tissue signals had increased performance. Distribution of the Water Index visually showed improved ability to discriminate leaf RWC as compared to individual wavelengths but this did not translate to improved model performance.</div><div><br></div><div>For future work, more data should be collected to improve model robustness and hyperspectral imaging should include SWIR wavelengths that have previously been found useful for predicting relative water content. Exploring indices composed from current spectral bands may lead to improved prediction performance.</div>

This thesis is written as a cumulative dissertation. It presents methods and results which contribute to an improved understanding of the spatio-temporal variability of fog and fog deposition. The questions to be answered are: When is there how much fog, and where and how much fog is deposited on the vegetation as fog precipitation? Freely available data sets serve as a database. The meteorological input data are obtained from the Climate Data Center (CDC) of the German Meteorological Service (DWD). Station data for temperature, relative humidity and wind speed in hourly resolution are used. In addition, visibility data are used for validation purposes. Furthermore, Global Forest Heights (GFH) data from the National Aeronautics and Space Administration (NASA) are used as vegetation height data. The data from NASA’s Shuttle Radar Topography Mission (SRTM) is used as a digital elevation model. The first publication deals with gap filling and data compression for further calculations. This is necessary since the station density for hourly data is relatively low, especially before the 2000s. In addition, there are more frequent gaps in hourly data than in, for instance, daily data, which can thus be filled. It is shown that gradient boosting (gb) enables high quality gap filling in a short computing time. The second publication deals with the determination of the fog, especially with the liquid water content (lwc). Here the focus is on the correction of measurement errors of the relative humidity as well as methods of spatial interpolation are dealt with. The resulting lwc data for Germany with a temporal resolution of one hour and a spatial resolution of one kilometre, are validated against measured lwc data as well as visibility data of the DWD. The last publication uses the data and methods of the two previous publications. The vegetation and wind speed data are also used to determine fog precipitation from the lwc data. This is validated using data from other publications and water balance calculations. In addition to the measured precipitation, the fog precipitation data are used as an input variable for the modelling. This is also one of the possible applications: To determine precipitation from fog, which is not recorded by standard measuring methods, and thus to make water balance modelling more realistic.:1 MOTIVATION 6 2 PROBLEM DEFINITION AND TARGET SETTING 6 3 STRUCTURE 7 4 MODEL LIMITS 9 5 PUBLICATIONS 9 6 OUTLOOK 29

[ES] La escasez de agua se está convirtiendo en un problema en zonas áridas y semiáridas del mundo, donde se localiza parte de la producción de los principales cultivos hortícolas, como en el área mediterránea. La sequía es uno de los principales factores limitantes en la agricultura y está afectando gravemente a la producción de cultivos hortícolas. La mejora de la productividad del agua en la agricultura puede lograrse mediante la utilización de determinadas estrategias. El riego deficitario consiste en el aporte de agua por debajo de las necesidades de riego (NR) de los cultivos, de manera que se produce una reducción de la evapotranspiración. Puede realizarse de manera continua o sostenida (RDS) o controlada (RDC). Con el riego deficitario se puede mejorar la eficiencia del uso del agua de riego, manteniendo el rendimiento, e incluso en ocasiones, podría mejorarse la calidad de la cosecha. En este estudio, realizado en el Centro Experimental Cajamar de Paiporta (Valencia) se evalúa el efecto del riego deficitario en cuatro de los principales cultivos hortícolas cultivados al aire libre, en el área mediterránea: coliflor, cebolla, pimiento y sandía. En la evaluación se ha analizado: crecimiento y estado hídrico de las plantas, rendimiento, eficiencia del uso del agua de riego, calidad de la producción y rentabilidad de los cultivos. En la primera campaña se ensayó el RDS, lo que permitió establecer las diferentes etapas de crecimiento de cada cultivo, que se utilizaron en las siguientes campañas en el RDC. En los cuatro cultivos, las plantas control (100% NR) han mostrado un adecuado estado hídrico, tanto en el contenido relativo de agua como en el índice de estabilidad de la membrana, mientras que las sometidas a un RDS severo, han mostrado los menores valores de ambos índices. El efecto negativo del riego deficitario sobre el rendimiento ha resultado menos importante en los cultivos de otoño-invierno que en los cultivos de primavera-verano, especialmente en la coliflor. El RDS del 50% NR ha reducido drásticamente el rendimiento comercial y, consecuentemente, los ingresos brutos, aunque haya supuesto una mejora en la eficiencia del uso del agua de riego para los cultivos de otoño-invierno. Del análisis individual de los cultivos se deduce que el rendimiento en pellas de coliflor obtenidas con RDS al 75% NR o RDC al 50% NR durante la fase juvenil, se ha mantenido en niveles similares al control, mejorando la eficiencia del uso del agua de riego. En cebolla, en caso de restricción hídrica severa, sería aconsejable aplicar RDS con el 75% NR o RDC al 50% NR durante la maduración del bulbo, ya que estas estrategias han disminuido ligeramente el rendimiento, mejorando la eficiencia del uso del agua de riego. En condiciones menos restrictivas, RDC al 75% NR durante la maduración del bulbo ha dado lugar a un rendimiento satisfactorio, con un aumento de la eficiencia del uso del agua de riego. En pimiento dulce italiano, la aplicación de RDC al 75% NR durante la recolección ha dado lugar a una reducción considerable del rendimiento, y por tanto, de los ingresos brutos, aunque con importantes ahorros de agua y con un incremento en el contenido de sólidos solubles y de compuestos fenólicos de los frutos. Acortando el ciclo de cultivo hasta principios de septiembre, cuando ya se ha cosechado la mayor parte del rendimiento comercial, se conseguiría un importante ahorro de agua y permitiría utilizar la parcela en otros cultivos. El RDS al 75% y al 50% NR, o RDC al 50% NR durante la cosecha han dado lugar a una alta incidencia de frutos afectados por blossom-end rot. En sandía puede recomendarse la aplicación de RDC, tanto al 75% como al 50% NR durante la maduración del fruto, ya que ha conducido a rendimientos comerciales aceptables. De manera general se puede afirmar que la aplicación de RDS y de RDC en los cuatro cultivos, no ha afectado de manera importante a la calidad de la producción, / [CAT] Resum L'escassesa d'aigua s'està convertint en un problema en zones àrides i semiàrides del món, on es localitza part de la producció dels principals cultius hortícoles, com és el cas de l'àrea mediterrània. La sequera és un dels principals factors limitants en l'agricultura i està afectant greument a la producció de cultius hortícoles. La millora de la productivitat de l'aigua en l'agricultura en general, i en l'horticultura en particular, es pot aconseguir mitjançant la utilització de determinades estratègies. El reg deficitari consisteix en l'aportació d'aigua per sota de les necessitats de reg (NR) dels cultius, de manera que es produeix una reducció de l'evapotranspiració. Es pot fer de manera contínua o sostinguda (RDS) o controlada (RDC). Amb el reg deficitari es pot millorar l'eficiència de l'ús de l'aigua de reg, mantenint el rendiment, i fins i tot de vegades, podria conduir a una millora de la qualitat de la collita. En aquest estudi, realitzat al Centre Experimental Cajamar de Paiporta (València, Espanya) s'avalua l'efecte del reg deficitari en quatre dels principals cultius hortícoles conreats a l'aire lliure, a l'àrea mediterrània: dos de cultiu de tardor-hivern (coliflor i ceba) i dues de cultiu primaveral-estival (pimentó i meló d'Alger). En l'avaluació s'han analitzat els següents paràmetres: creixement i estat hídric de les plantes, rendiment, eficiència de l'ús de l'aigua de reg, qualitat de la producció i rendibilitat dels cultius. A la primera campanya es va assajar el RDS, el que va permetre establir les diferents etapes de creixement de cada cultiu, que es van utilitzar en les següents campanyes en el RDC. En els quatre cultius, les plantes control (100% NR) han mostrat un adequat estat hídric, tant en el contingut relatiu d'aigua com en l'índex d'estabilitat de la membrana, mentre que les sotmeses a un RDS sever, han mostrat els menors valors d'ambdós índexs. L'efecte negatiu del reg deficitari sobre el rendiment ha resultat menys important en els cultius de tardor-hivern que en els cultius de primavera-estiu, especialment en la coliflor. El RDS del 50% NR ha reduït dràsticament el rendiment comercial i, conseqüentment, els ingressos bruts, encara que hagi suposat una millora en l'eficiència de l'ús de l'aigua de reg per als cultius de tardor-hivern. De l'anàlisi individual dels cultius es dedueix que el rendiment de coliflors obtingudes amb RDS al 75% NR o RDC al 50% NR durant la fase juvenil, s'ha mantingut en nivells similars al control, millorant l'eficiència de l'ús de l'aigua de reg. En ceba, en cas de restricció hídrica severa, seria aconsellable aplicar RDS amb el 75% NR o RDC al 50% NR durant la maduració del bulb, ja que aquestes estratègies han disminuït lleugerament el rendiment, millorant l'eficiència de l'ús de l'aigua de reg . En condicions menys restrictives, RDC al 75% NR durant la maduració del bulb ha donat lloc a un rendiment satisfactori, amb un augment de l'eficiència de l'ús de l'aigua de reg. En pimentó dolç italià, l'aplicació de RDC al 75% NR durant la recol·lecció ha donat lloc a una reducció considerable del rendiment, i per tant, dels ingressos bruts, encara que amb importants estalvis d'aigua i amb un increment en el contingut de sòlids solubles i de compostos fenòlics dels fruits. Retallant el cicle de cultiu fins a principis de setembre, quan ja s'ha collit la major part del rendiment comercial, s'aconseguiria un important estalvi d'aigua i permetria utilitzar la parcel·la en altres cultius. El RDS al 75% i al 50% NR, o RDC al 50% NR durant la collita han donat lloc a una alta incidència de fruits afectats per blossom-end rot. En meló d'Alger es pot recomanar l'aplicació de RDC, tant al 75% com al 50% NR durant la maduració del fruit, ja que ha conduït a rendiments comercials acceptables. De manera general es pot afirmar que l'aplicació de RDS i de RDC en els quatre cultius, no ha afectat de maner / [EN] Water scarcity is becoming a critical problem in arid and semi-arid areas of the world, where part of the production of the main horticultural crops is located, as is the case of the Mediterranean area. Drought is one of the main limiting factors in agriculture and it is seriously affecting the production of horticultural crops. The improvement of water productivity in agriculture in general, and in horticulture in particular, can be achieved through the use of certain strategies. Deficit irrigation consists of the supply of water below the irrigation water requirements (IWR), so that there is a reduction in evapotranspiration. It can be done continuously (CDI) or regulated (RDI). With deficit irrigation, the irrigation water use efficiency can be improved, maintaining yield, and it could even lead to an improvement in the quality of the harvest. This study, carried out at the Cajamar in Paiporta Experimental Center (Valencia, Spain), analyzes the effect of deficit irrigation on four of the main cultivated horticultural crops, open field cultivated in the Mediterranean area: two of autumnal-winter crops (cauliflower and onion) and two spring-summer crops (pepper and watermelon). In the evaluation, the following parameters have been analyzed: plant growth and water status, yield, irrigation water use efficiency, quality of production and crop profitability. In the first season the CDI was tested, which allowed to establish the different growth stages for each crop, which were used in the following season for the RDI. In the four crops, the control plants (100% IWR) have shown an adequate water status, in terms of both relative water content and membrane stability index, while those subjected to a severe CDI, have shown the lowest values of both indexes. The negative effect of deficit irrigation on yield has been less important in autumn-winter crops than in spring-summer crops, especially in cauliflower. The CDI at 50% IWR has drastically reduced the marketable yield and, consequently, the gross revenue, although it has supposed an improvement in the irrigation water use efficiency for the autumn-winter crops. From the individual analysis of the crops, it can be stated that cauliflower yield obtained with CDI at 75% IWR or RDI at 50% IWR during the juvenile phase, has remained at levels similar to the control, improving the irrigation water use efficiency. In relation to onion, in case of severe water restriction, it would be advisable to apply CDI with 75% IWR or RDI at 50% IWR during bulb ripening, since these strategies have slightly decreased yield, improving the irrigation water use efficiency. In less restrictive conditions, RDI at 75% IWR during the bulb maturation has led to a satisfactory yield, with an increase in the irrigation water use efficiency. In Italian sweet pepper, the application of RDI to 75% IWR during the harvesting has resulted in a considerable reduction of the yield, and therefore, of the gross income, although with important water savings and increasing the fruit soluble solids and phenolic compounds content. By shortening the cultivation cycle until the beginning of September, when most of the marketable yield has already been harvested, significant water savings would be achieved, and the land could be used in other crops. CDI at 75% IWR and 50% IWR, or RDI at 50% IWR at harvesting have resulted in a high incidence of fruit affected by blossom-end rot. In watermelon the RDI application can be recommended, both 75% and 50% IWR, during the fruit ripening, since it has led to acceptable marketable yields. In general terms, it can be affirmed that the application of CDI and RDI in the four crops has not significantly affected the product quality, in terms of the analyzed parameters. / My grateful thanks to the Cultural Affairs and Mission Sector, Egyptian Ministry of Higher Education for supporting me with a scholarship. / Abdelkhalik, AGA. (2019). Effect of continued and regulated deficit irrigation on the productivity of four vegetable crops in open-field conditions in the Mediterranean area [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/129868 / TESIS

No description available.