Made available in DSpace on 2014-06-11T19:33:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-04-24Bitstream added on 2014-06-13T20:45:36Z : No. of bitstreams: 1 cortez_jw_dr_jabo.pdf: 1888466 bytes, checksum: 9a45b02d248279bb40fbf4c5698b607b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste trabalho foi avaliar a influência dos sistemas de adubação (na pré-semeadura e na semeadura) e dos consórcios de culturas intercalares (milho + feijão-mucuna-cinza-anã, milho + feijão-guandu-anão e milho + feijão-lab-lab) na cultura do milho no primeiro ano; e no segundo ano avaliar a influência dos sistemas de adubação (na pré-semeadura e na semeadura) e dos manejos de resíduos (rolo-faca, roçadora e triturador de palhas) na cultura da soja. O experimento foi realizado na FCAV- UNESP utilizando-se o delineamento em blocos ao acaso no esquema fatorial (2 x 3) com quatro repetições nos dois anos agrícolas. Os componentes avaliados foram na máquina, no solo e na planta. O diâmetro do colmo, a altura de inserção da primeira espiga e a altura de plantas de milho resultaram em maiores valores para o sistema de adubação na semeadura. O número de fileiras, espigas viáveis, índice de espiga, estande final, biomassa seca no solo, produtividade, fluxo de palha, fluxo de sabugo, fluxo de grãos e as perdas na colheita não foram afetados pelos sistemas de adubação e pelos consórcios, na cultura do milho. A avaliação da distribuição longitudinal de plantas de soja na semeadura, e o fluxo de material de soja na colhedora não foram afetados pelos sistemas de adubação e pelos manejos dos resíduos. As plantas de soja obtiveram maior altura de inserção da primeira vagem e número de vagens no manejo com rolo-faca. A produtividade da soja não foi afetada. / The aim of the present study was to evaluate the influence of the fertilization systems (at pre-sowing and sowing) and those consorts of intercalated crops (corn + bean-Stizolobium deeringianum, corn + bean-Cajanus cajan and corn + bean-Dolichos lab lab) in corn crop during the first year; and to evaluate, in the second year, the influence of the fertilization systems (at pre-sowing and sowing) and the management of chaff (knife roller, rotary mower and straw crusher) in the soybean crop. The experiment was done at FCAV-UNESP with totally randomized delineation, on factorial scheme (2x3) with four repetitions during the two agricultural years. The components evaluated were: machine, soil and plant. The stalk diameter, the insertion height of the first cob and the height of corn plants presented higher values for the fertilization system at sowing. The number of rows, viable cobs, cob rate, final stand, dry mass on soil, productiveness, flow of straw, cob and grains and the losses in the harvest were not affected by the fertilization systems and by the consorts in the corn crop. The evaluation of longitudinal distribution of soy plants at sowing and the soybean material flow in the harvester were not affected by the fertilization systems and by the management of chaff. The soybean plants presented higher height of insertion of the first string bean and the number of string beans in the knife roller management. The soybean yield was not affected.

Made available in DSpace on 2014-06-11T19:28:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-11-01Bitstream added on 2014-06-13T19:16:24Z : No. of bitstreams: 1 santos_ep_me_jabo.pdf: 811104 bytes, checksum: bcd035d537d9aeb8084fc66fc53510f8 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Copercana / O arranquio, momento de grande importância na produção do amendoim, que se realizada de forma ineficiente pode representar em alguns casos perdas de até 30%. Considerando-se o curto período de tempo disponível para o cultivo do amendoim em áreas de reforma de canaviais, este trabalho teve por objetivo testar a hipótese de que é possível antecipar o arranquio mecanizado do amendoim, sem acarretar prejuízos ao produtor. Para tanto, realizou-se o arranquio do amendoim aos 120, 125, 130, 135 e 140 dias após a semeadura, sendo os resultados avaliados por análise estatística descritiva e multivariada, com uso de análise de variância, para as variáveis: porcentagem de maturação, teor de água das vagens e do solo, índice de cone, perdas no arranquio mecanizado e produtividade. A análise de variância indicou que o adiamento do arranquio de amendoim IAC runner 886 não está diretamente relacionado com o aumento da produtividade, e que as perdas no arranquio tendem a aumentar gradativamente com o aumento do tempo de permanência da cultura no campo, sendo que aos 135 dias após a semeadura, ocorre aumento expressivo destas perdas. A análise multivariada possibilitou analisar de forma conjunta a ação das variáveis, indicando que existe correlação inversa do índice de cone com a produtividade, e entre o teor de água do solo e das vagens com a maturação, além de evidenciar a correlação entre as perdas visíveis e invisíveis do arranquio / In the digging, moment of great importance in the production of peanuts, is conducted in an inefficient way, in some cases may represent losses of up to 30%. Considering the short time available for the cultivation of peanuts in sugarcane areas of reform, this study aimed to test the hypothesis that it is possible to anticipate the mechanical digging from peanuts without causing damage to the producer. Thus, it was carried out the digging the peanut at 120, 125, 130, 135 and 140 days after sowing, and the results were evaluated by multivariate and descriptive statistics analysis, using analysis of variance for the variables: percentage of maturity, water content of the pod and the soil, cone index, losses on the pull-off mechanized and productivity. Analysis of variance indicated that the postponement of the pull-off of the peanut IAC runner 886 is not directly related to increased productivity, and pull-off losses tend to increase gradually with the increase of residence time of the culture in the field, and that 135 days after sowing, there is significant increase in these losses. Multivariate analysis allowed to analyze jointly the action of the variables, indicating that there is an inverse correlation of cone index with productivity, and between the water content of soil and the pods with the maturation, and also highlights the correlation between visible and invisible losses of the digging

Made available in DSpace on 2014-06-11T19:28:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-23Bitstream added on 2014-06-13T18:34:43Z : No. of bitstreams: 1 morgado_cma_me_jabo.pdf: 767923 bytes, checksum: cd0b4eb5553754106d2e9e461c70a462 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo foi estabelecer a importância do estádio de maturação e da refrigeração, na conservação de goiabas Kumagai, Paluma, Pedro Sato, Sassaoka e Século XXI e avaliar a qualidade dos seus produtos minimamente processados (PMP). Frutos “de vez” e maduros foram armazenados a 21ºC e a 10ºC e avaliados a cada 2-3 dias. Nos PMP, os frutos foram descascados, cortados ao meio, as sementes eliminadas, enxaguados com água clorada, embalados, armazenados a 3°C (75%UR) e avaliados a cada 2 dias. Os frutos e os PMP foram avaliados quanto aos teores de ácido ascórbico (AA), sólidos solúveis (SS) e acidez titulável (AT), massa fresca e cor. Os frutos quanto à atividade antioxidante total (AAT), ABTS e FRAP, polifenóis extraíveis totais (PExT), resistência, aparência e podridões e os PMP quanto ao rendimento e microbiologicamente. A vida útil dos frutos maduros, a 21ºC, foi de 4 dias para a Kumagai, Paluma, Sassaoka e Sec XXI, e de 2 dias para a P Sato. A 10ºC, goiabas Kumagai e Sassaoka conservaram-se por 9 dias, enquanto Paluma, P Sato e Sec XXI por 6 dias. Goiabas “de vez”, Kumagai, Paluma e Sassaoka, a 21ºC apresentaram vida útil de 6 dias, que se prolongou para 12 dias a 10ºC. Goiabas P Sato e Sec XXI, a 21ºC apresentaram vida útil de 4 dias, que aumentou para 9 dias a 10ºC. Goiabas Sassaoka apresentaram a maior vida útil, os maiores teores de SS e os menores de AT e mantiveram os teores de PExT, com aumento na AAT (ABTS), e nos teores de AA. A vida útil dos PMP foi de 12 dias. O rendimento das goiabas P Sato, em PMP não descascado, foi o maior, 69,65%. Os PMP feitos com goiabas descascadas apresentaram menor rendimento, maior perda de massa e os menores teores de AA / The objective was to establish the importance of maturation stage and of refrigeration for the conservation of Kumagai, Paluma, Pedro Sato, and Sassaoka Século XXI guavas and to evaluate the quality of its minimally processed products (PMP). Fruit in mature and ripe stage were stored at 21ºC and 10ºC and evaluated every 2-3 days. In PMP, the fruits were peeled, cut in the midle, had seeds removed, were rinsed with chlorinated water, packaged, stored at 3°C (75% RH) and evaluated every 2 days. PMP and intact fruits were evaluated by ascorbic acid (AA), soluble solids (SS) and titratable acidity (TA) content, fresh mass and color. Intact fruits were also evaluated by total antioxidant activity (TAA), ABTS and FRAP, total polyphenols extractable total (PExT), resistence, appearance and rotting evolution and PMP for yield and microbiologically. The shelf life of ripe fruit, at 21ºC, was 4 days for Kumagai, Paluma, Sassaoka and Sec XXI, and 2 days for P Sato. At 10ºC, Kumagai and Sassaoka guavas were preserved for 9 days, while Paluma, P Sato and Sec XXI for 6 days. Mature guavas, Kumagai, Paluma and Sassaoka, at 21ºC showed shelf life of 6 days, which prolonged for 12 days at 10°C. P Sato a nd Sec XXI guavas, at 21ºC had shelf life of 4 days, which increased to 9 days when kept at 10°C. Sassaoka guavas had the biggest shelf life and SS content, the lowest AT content, kept the PExT content the same, with increasing values for AAT (ABTS), and AA content. The shelf life of PMP was 12 days. The yield of P Sato guava, in not peeled PMP, was 69.65%, the highest. The PMP made with peeled guavas had lower yield, higher weight loss and the lowest AA content

Made available in DSpace on 2014-06-11T19:28:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-23Bitstream added on 2014-06-13T19:58:02Z : No. of bitstreams: 1 cortez_jw_me_jabo.pdf: 2582445 bytes, checksum: 22ed4633434e73fc9d8fd7a9a038144f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A utilização da cultura da soja no Sistema Plantio Direto (SPD) requer sempre o desenvolvimento de pesquisas. O objetivo desse trabalho foi avaliar a densidade de semeadura (15, 16 e 20 plantas por metro) e profundidade de deposição do adubo (11, 14 e 17 cm) em área de SPD com soja. O experimento foi realizado na UNESP/Jaboticabal, utilizando-se o delineamento de parcelas subdivididas em blocos ao acaso com quatro repetições. Foram mensurados no solo: cobertura antes e após a semeadura, umidade, densidade, resistência à penetração e volume mobilizado; nas máquinas: capacidade de campo, velocidade, consumo de combustível, patinagem, fluxo de massa, de grãos e total na colhedora e as perdas na colheita; e os parâmetros agronômicos da soja. Os parâmetros de solo não foram afetados pelos tratamentos, exceção feita à porcentagem de cobertura do solo aos 30 dias pela cultura da soja que foi significativa, com a maior densidade de semeadura apresentando-se maior. Os fluxos de massa, de grãos e total foram afetados pelas densidades de plantas e a profundidade do adubo. Nas máquinas observou-se a influência da profundidade de deposição do adubo no consumo de combustível, e na patinagem do trator. Na planta; a porcentagem de espaçamentos aceitáveis diminuiu com o aumento das densidades de semeadura. / To growing acceptance of the no tillage causes the development of researches. The objective of this work was to evaluate the sowing density (15, 16 and 20 plants m-1) and furrow fertilizer shaft depth (11, 14 and 17 cm), in the no tillage with soybean. The experiment was accomplished in the UNESP/Jaboticabal, in experimental design split-plot scheme, with randomized blocks, with four replicates. The soil parameters were: covering before and after the sowing, content moisture, bulk density, resistance to the penetration and mobilized area; in the machine: velocity, operational field capacity, fuel, tractor sliding, mass flow in the harvesting and harvesting losses; and agronomic characteristics of the soybean. The soil parameters were not affected for the proposed treatments, but just the covering percentage of the soil to the 30 days for the culture of the soy was significant with the largest density presenting the largest covering. In the machine it was observed influences of the furrow fertilizer shaft depths in the consumptions of fuel, being the same observed for the tractor sliding. The flow of material other grain, grains and total were affected. In the plant: the percentage of acceptable spacing decreased with the increase of the density.

Resumo: Atualmente, com o alto consumo da cana de açúcar, indústrias buscam melhorias na gestão ambiental do processo produtivo do setor sucroalcooleiro, passando assim, inevitavelmente, pela melhor produção da cana, seus produtos e subprodutos, consequentemente uma melhor maneira de conduzir a colheira da planta. Com isso começam a surgir programas como o estudado neste trabalho "O Cana Limpa", que se espalha pelas usinas do país. A sustentabilidade de um Programa de tal natureza não depende apenas de quem o patrocina ou do empresário, mas também, primordialmente daqueles que são afetados diretamente por este. Esta premissa e a dúvida sobre a adequação do programa dos trabalhadores motivaram esta proposta. Certamente o programa deve ter sido concebido para contemplar não só a produtividade para a empresa, mas também, melhores condições de vida no trabalho para os cortadores. Mas que opinião tem os mesmos? Assim, na busca de resposta a esta questão o objetivo desse trabalho é o de avaliar o Programa Cana Limpa, desde o ponto de vista do cortador verificando seus pontos fortes, fracos e melhorias necessárias ao Programa. Embora a participação do homem se dê em várias das fases dos processos produtivos do setor sucro-alcooleiro, a presente proposta enfoca apenas o trabalho durante a colheita de cana de açúcar. Esta pesquisa quanto ao método tem duas fases. A primeira é qualitativa e exploratória. Nesta fase busca levantar as variáveis para avaliar o programa. Após a identificação das variáveis tem-se uma segunda fase, quantitativa descritiva, onde se avalia o grau de existência das variáveis encontradas, ou seja, estas variáveis da primeira fase não utilizadas na elaboração de questões do instrumento de coleta de dados. Nesta fase é construído um instrumento de coleta de dados com questões fechadas utilizando escala ordinal... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Due to the high consumption of sugar cane, industries have been searching to improve environmental management in the sugar and alcohol production processes, thus resulting in improved production of sugar cane and its by products as well as improved harvesting techniques. The "Cana Limpa" ("clean sugar cane") is one of the programs that arose as a result of this search for improvement in sugar cane production and harvesting. To say that a program is sustainable depends not only on the sponsor or the entrepreneur, but also on the people that are directly affected by such a program. This and the question whether or not the program will be adequate to the workers, motivated our proposal. It is certainly true that the program was conceived to embrace not only productivity, but also better working conditions to the harvesters. But what do they think about it? The objective of this study is to evaluate the "Cana Limpa" Program from the point of view of the harvester, and analyze its strengths and weaknesses as well as the need for improvements. Even though man participates in various stages of the sugar and alcohol production process, this study focus only on the harvest of sugar cane. The method used in this research is twofold: the first part is qualitative and exploratory. We aimed at obtaining variables to evaluate the program; the second part is quantitative and descriptive, that is, we measurehow many times the variables occur. During this part of the research, we built an instrument to collect data, with closed questions and ordinal scale. The questionnaires were distributed to the harvesters in their place of work. Evaluating the "Cana Limpa" program with an ordinal scale, as we did during the second part of this study, with three discrete levels (better than, equal to, worse than) allowed us, by means of descriptive statistics, to obtain the distribution of each one of these... (Complete abstract click electronic access below) / Orientador: Rosani de Castro / Coorientador: Alcides Padilha / Banca: Charbel José Chiappetta Jabbour / Banca: Valdeir Rejanildo Vidrik / Mestre

Este estudo procurou entender porque as usinas e destilarias fazem uso de estratégias distintas na coordenação vertical da colheita da cana-de-açúcar, pois verifica-se no setor a presença conjunta de empresas que utilizam a terceirização total da frota, outras que utilizam a terceirização de forma parcial (integração vertical parcial) e ainda, firmas que empregam estruturas totalmente verticalizadas na condução dessa atividade. Assim, foram analisados os mecanismos e critérios de escolha utilizados pelas empresas ao estabelecerem os arranjos institucionais que coordenam as atividades de corte, carregamento e transporte da cana-de-açúcar, buscando um alinhamento entre os arranjos adotados e os aspectos teóricos que justificassem essa opção. Durante a análise, também foram descritas as principais dificuldades enfrentadas pelos agentes envolvidos no processo de terceirização da colheita (usinas/destilarias e prestadores de serviço), pretendendo contribuir para a discussão sobre o tema entre os profissionais da área. O ferramental teórico utilizado para o embasamento do estudo foi composto a partir da conjugação de elementos da Teoria Neoclássica, da Economia dos Custos de Transação e da Teoria das Competências Dinâmicas. O estudo se apoiou em dados secundários, obtidos de diversas fontes, e em dados primários, coletados a partir de entrevistas em profundidade com os agentes envolvidos no processo analisado. Participaram da amostra 33 usinas/destilarias (30 localizadas no Estado de São Paulo e 3 no Estado do Paraná) e 6 empresas prestadoras de serviço. A presença de diferentes arranjos entre as usinas/destilarias foi explicada pela percepção distinta dos custos de transação e de produção envolvidos nessa escolha, e pela própria heterogeneidade de recursos e competências entre as empresas. Apenas no caso do corte manual observou-se uma tendência de convergência dos arranjos em direção a estruturas verticalizadas, que pode ser explicada, principalmente, pela maior pressão dos órgãos e agentes privados e públicos nos últimos anos para o cumprimento das normas trabalhistas e de segurança e saúde do trabalhador rural, visando, entre outras coisas, a eliminação da terceirização do corte manual. Com relação às dificuldades enfrentadas pelas usinas/destilarias que fazem uso da terceirização e pelos prestadores de serviços, verificou-se que os principais pontos de divergência entre os agentes referem-se ao tempo de duração dos contratos, aos mecanismos de monitoramento e controle utilizados e a forma de pagamento dos serviços prestados. / This study has aimed at understanding why sugar/alcohol mills and distilleries make use of distinct strategies in the vertical coordination of the sugarcane harvesting system. The sector presents three different types of institutional arrangements to perform harvesting activities: (i) companies using completely outsourced services; (ii) mills that use partly outsourced services (partial vertical integration); and (iii) firms that employ totally verticalized structures. Therefore, we have analyzed the mechanisms and criteria of choice used by the mills for establishing institutional arrangements to coordinate the harvesting, truck loading, and transportation of sugarcane. In this enquiry, we have searched for alignments between the arrangements adopted and the theoretical aspects that could justify such choices. During the analysis, we have also described the main difficulties faced by the agents involved in the outsourcing process (mills/distilleries and service providers), intending to contribute to professionals in the area. The theoretical fundamentals of the study concerned elements of Neoclassical Theory, of Transaction Cost Economics, and of Dynamic Capabilities Theory. The research is based on secondary data obtained from several sources and on primary data collected in thorough interviews with the agents involved. The sample consists of 33 mills/distilleries (30 located in São Paulo State and three in Paraná State) and of six service-providing firms. The different institutional arrangements among mills/distilleries result from distinct perceptions of the transaction and production costs involved in such choice as well as from the heterogeneity of resources and competences among companies. Strictly in the case of manual harvesting, we have observed a trend towards verticalized structures. This is mainly due to the fact that both governmental and private agents have pressured such firms to respect labor norms as well as the workers? security and health regulations in the latest years, viewing at the extinction of outsourced manual harvesting, among other reasons. As to the problems faced by mills/distilleries that use outsourced service and service providers, we have found out that the main disagreements among agents regard the duration of contracts, the monitoring mechanisms and the form of payment for services rendered.

Apesar de vÃrios estudos jà desenvolvidos com a cultura da acerola, ainda existe um grande nÃmero de genÃtipos a ser caracterizados sob vÃrios aspectos, principalmente os genÃticos. Adicionalmente, alÃm dos fatores genÃticos, a composiÃÃo dos frutos da aceroleira pode ser afetada em funÃÃo das condiÃÃes ambientais durante seu desenvolvimento (estaÃÃo seca / Ãmida). Diante da demanda por novos clones a Embrapa AgroindÃstria Tropical desenvolveu, nos anos de 1996 a 2007, um programa de melhoramento genÃtico da aceroleira, lanÃando no ano de 2003 quatro clones recomendados para o Estado do CearÃ: BRS 235(Apodi), BRS 236 (Cereja), BRS 237 (Roxinha) e BRS 238 (Frutacor), originando atravÃs de seleÃÃo o Jardim de Sementes. Assim, o objetivo deste trabalho consistiu na caracterizaÃÃo dos genÃtipos de aceroleira do Jardim de Sementes por meio de variÃveis agronÃmicas e de pÃs-colheita e avaliaÃÃo da existÃncia de diversidade genÃtica desse material. O experimento foi instalado no campo Experimental de Pacajus (CE), sob delineamento inteiramente casualizado, avaliou-se 36 genÃtipos para variÃveis agronÃmicas (morfologia, fenologia e produÃÃo) e 25 genÃtipos para as variÃveis de pÃs-colheita (peso, firmeza, sÃlidos solÃveis, acidez titulÃvel, relaÃÃo SS/AT, pH da polpa, vitamina C, antocianina, flavonÃides, atividade antioxidante e polifenÃis), com trÃs repetiÃÃes e nas estaÃÃes seca de 2009 e Ãmida e seca de 2010, foi realizada anÃlise descritiva para as variÃveis agronÃmicas, na qual verificou-se que os genÃtipos apresentam altura e diÃmetro adequados para plantios comerciais. Observaram-se picos de floraÃÃo nos meses de abril, outubro e dezembro e cinco picos de frutificaÃÃo. Quanto à produtividade, destacaram-se os clones 9, 14, 28, 37 e 38. Foram realizadas anÃlises univariada e conjunta onde foram observadas mudanÃas nas variÃveis de pÃs-colheita durante as estaÃÃes com relaÃÃo a peso, sÃlidos solÃveis, acidez titulÃvel, vitamina C, antocianinas, atividade antioxidante e polifenÃis; entretanto, as mudanÃas na firmeza, pH e flavonÃides nÃo foram significativas. AtravÃs da anÃlise multivariada verificou-se a existÃncia de diversidade entre os materiais, destacando-se os clones 13 e 37. Utilizou-se do Ãndice de seleÃÃo de Mulamba e Mock para escolha dos materiais que apresentassem uma sÃrie de atributos favorÃveis quanto as caracterÃsticas de pÃs-colheita onde destacaram-se os clones 3, 13, 14, 27 e 38. / Although several studies have developed the culture of acerola, there is still a large number of genotypes to be characterized in many ways, mainly genetic. Additionally, from genetic factors, the composition of acerola fruit can be affected depending on environmental conditions during development (season dry/wet). Giver the demand for new clones to postharvest developed in the years 1996 to 2007, a breeding program of acerola, launching in 2003, four clones recommended for the state of CearÃ: BRS 235 (Apodi), BRS 236 (Cereja), BRS 237 (Roxinha) and BRS 238 (Frutacor), leading through the selection of garden seeds. The objective of this study was to characterize the genotypes of acerola garden seed through agronomic variables and post-harvest assessment of the existence of genetic diversity of this material. The experiment was installed in the field of experimental Pacajus (CE) under completely randomized design, 36 genotypes were evaluated for agronomc traits (morphology, phenology, and producyion) and 25 genotypes for post-harvest variables (weight, firmness, soluble solids, acidity, ratio ss/ta, pH of the pulp, vitamin C, anthocyanins, flavonoids, antioxidant activity and polyphenols) with three repetitions and the season dry of 2009 and wet and dry of 2010. Descriptive analysis was perfomed for agronomic traits in which it was found that the genotypes have height and diameter suitable for commercial plantation. Peaks were observed flowering in april, october and December and five fruiting peaks. As for productivity, the highlights were the clones 9, 14, 28, 37 and 38. We performed univariate and joint where we observed in variables during the post-harvest season with respect to weight, soluble solids, titratable acidity, vitamin C, anthocyanins, polyphenols and antioxidant activity, however, changes in texture, pH and flavonoids were significant. By multivariate analysis showed the existence of diversity among materials, especially clones 13 and 37. We used the selection index of Mulamba and Mock choice of materials to that presented a number of favorable attributes as the characteristics of post-harvest which highlights the clones 3, 13, 14, 27 and 38.

Master of Science / Food Science Institute / Sara E. Gragg / Leafy greens have been recognized as vehicles for transmission of foodborne pathogens and an effective pre-harvest intervention to control them is currently lacking. After harvest, lettuce is often subjected to chlorinated water to reduce the microbial load in the water and on the lettuce tissue. While moderately effective, there is also a need for improved postharvest interventions. The purpose of Objective I was to 1) determine potassium bisulfate efficacy at reducing populations of Escherichia coli (E. coli) and Listeria innocua (L. innocua) when applied pre-harvest to lettuce, and 2) assess the impact on product quality at harvest. Potassium bisulfate reduced E. coli populations on inoculated lettuce by 1.32 log₁₀ CFU/g (P=0.0002) and L. innocua by 1.18 log₁₀ CFU/g (P=0.0017). No detectable differences were observed in color (P>0.05); however, brown spots were observed on various leaves sprayed with potassium bisulfate. The purpose of Objective II was to employ a blend of benzalkonium chloride, acetic acid, and methyl paraben (BAM) as a postharvest wash on romaine and iceberg lettuce and to 1) determine efficacy at reducing populations of Listeria monocytogenes (L. monocytogenes), E. coli O157:H7 and Salmonella, 2) measure changes in aerobic bacteria throughout the shelf life, and 3) quantify benzalkonium chloride and methyl paraben residues post-washing. To quantify efficacy of BAM reducing pathogenic bacterial populations, fresh-cut romaine and iceberg lettuce were inoculated with L. monocytogenes, E. coli O157:H7, or Salmonella and washed in BAM at concentrations of 0%, 1%, 2% or 3% for one or five minutes. When plated on recovery media, contact time and wash concentration was not significant (P>0.05) for Salmonella on either product. Concentration was significant (P=0.0189) for L. monocytogenes on romaine; however, the greatest reduction observed was <1.0 log₁₀ CFU/g. The 3% wash significantly reduced E. coli O157:H7 on romaine by 1.75 log₁₀ CFU/g, which is 0.66 log₁₀ CFU/g better than the 0% wash. Following washing, wash water was analyzed and data demonstrate that all wash concentrations significantly (P≤0.05) reduced each foodborne pathogen by >2.0 log₁₀ CFU/g in the wash water. To quantify benzalkonium chloride and methyl paraben residues, as well as changes in aerobic bacteria and product quality, fresh-cut romaine and iceberg lettuce were subjected to a 1 minute wash in BAM at concentrations of 0%, 1%, 2%, or 3% and immediately sampled to determine aerobic populations and product quality. Concentrations 0% and 2% were also packaged into retail storage bags and sampled on days 0, 3, 5, and 7. Residues were quantified on these days as well. On day 0, aerobic populations did not vary according to wash concentration (P>0.05). With regards to shelf-life data, the 2% wash significantly reduced (P=0.0203) aerobic bacteria on romaine lettuce; however, no significant difference was observed on iceberg lettuce (P=0.0819). With regards to overall visual appearance of romaine or iceberg lettuce, no significant difference was detected between 0% and 2% BAM washes for each day throughout the shelf-life study (P>0.05). Methyl paraben and benzalkonium chloride residues were <5.0 and <10.0 ppm, respectively, on both products on each sampling day.

This thesis deals with the fast-growing trees (FGT). The aim of the work will be to create a list of parameters, limiting or conditioning the creation of supply chains (or clusters), focused on the exploitation of local renewable energy sources. The theoretical part will focus on the harvest of FGT and their possible utilization. The practical part includes the views of people, representing different areas. The practical part will also include the calculation of area performance and initial costs in setting up FGT at the village of Smilovy Hory. In conclusion, findings will be summarized and evaluated.

Informing monitoring and surveillance efforts for invasive species is crucial for effective management to minimize negative ecological, economic, and social impacts. Management responses to the invasion of silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis)—collectively termed bigheaded carps—in the upper Illinois waterway involve removal efforts to maintain low abundance near the invasion front and surveillance to detect any spread farther upriver. However, the efficiency and effectiveness of these efforts may be limited by the low abundance and patchy distributions of bigheaded carps near the invasion front, as well as the spatial scope of the gears used to sample them. My thesis applied mobile hydroacoustic sampling to understand the factors influencing the distributions of silver carp near the invasion front in the upper Illinois waterway, and factors influencing the observability and detectability of fishes with this gear. These results will be useful to inform removal and surveillance efforts in the upper Illinois waterway and reduce the risk of further upstream invasion into the Great Lakes. To assess factors influencing abundance, bi-monthly (March – October) mobile hydroacoustic sampling was conducted from 2017-2018 and paired with continuous environmental variable data collection in the Dresden Island and Marseilles pools, the upper two invaded pools of the Illinois waterway. Environmental variables collected were water temperature, dissolved oxygen, total dissolved solids, turbidity, chlorophyll-a concentration, blue-green algae concentration, and depth. Logistic and multiple regressions were performed within pool during each sampling period to describe factors associated with silver carp presence, and factors associated with their densities in areas where they were present. Silver carp densities fluctuated across space and time, suggesting environmental variables influenced distributions. Depth was the most consistent predictor of silver carp presence and density, with shallower depths associated with higher abundance. Specifically, in summer months, areas in large backwater habitats with lower temperature, higher dissolved oxygen, and higher chlorophyll-a concentration tended to hold more silver carp. These results suggest removal efforts should be focused on shallower depths within sites, and should target areas in backwaters with lower water temperature, higher dissolved oxygen, and higher chlorophyll-a concentrations during summer months. To inform bigheaded carp surveillance efforts upstream of the invasion front, the influence of factors of vessel speed, wind speed, and beam compensation on the observability (the proportion of the true abundance of fish that fall within the acoustic beam) and detectability (the proportion of observable fish that are detected) of fishes in large rivers with mobile horizontal hydroacoustic sampling was also evaluated. To accomplish this, 23 sets of paired trawl floats (buoys) were deployed in a 2.1 km stretch of the Dresden Island Pool, and four sets of replicate hydroacoustic surveys were conducted past them at three vessel speeds. Mean wind speed during each survey was obtained, and proportion of buoys observed and detected were quantified under two different maximum beam compensation values (6 dB and 12 dB). Results revealed significant interactions between vessel speed and wind speed, with observability increasing with wind speed at slow and fast vessel speeds, but decreasing at intermediate vessel speeds. Detectability decreased with greater wind speed across all vessel speeds, with more pronounced effects at slower vessel speeds. Significant positive effects of beam compensation occurred for both observability and detectability. These results suggest, to improve detection of bigheaded carps, sampling should be focused on calm days under moderate vessel speeds when analyzing with standard beam compensation values. Broadening beam compensation was shown to increase observability and detectability, but needs further investigation. Ultimately, these studies provide valuable information to assist management efforts to control bigheaded carps near the invasion front in the upper Illinois waterway, and detect any individuals that may spread farther upriver towards the Great Lakes.