Orientador: Rogério Lopes Vieites / Banca: Giuseppina Pace Pereira Lima / Banca: Vera Lúcia Mores Rall / Banca: Maria Monteiro Sigrist / Banca: Nelida Lúcia Del Mastro / Resumo: O presente trabalho teve por objetivo verificar os efeitos da radiação gama e de antimicrobianos naturais na conservação de melão minimamente processado, armazenado sob refrigeração. Foram realizados 4 experimentos: 1 e 2 - frutos de melão Cantaloupe e Pele de Sapo provenientes de Baraúna/RN e Juazeiro/BA, respectivamente; 3 e 4 - frutos de melão Cantaloupe e Gália provenientes da região de Cartagena (Espanha). Após a colheita, os frutos dos experimentos 1 e 2 foram transportados ao Laboratório de Frutas e Hortaliças da Faculdade de Ciências Agronômicas - UNESP - Botucatu/SP, e os dos experimentos 3 e 4 transportados para o Laboratório de Postrecolección e Refrigeración da Universidad Politécnica de Cartagena/Espanha. Após o processamento manual (corte em seções trapezoidais) os melões MP (minimamente processados) dos experimentos 1 e 2 foram acondicionados em embalagens de poliestireno expandido recobertas com filme de polietileno e irradiados nas doses: 0,0kGy; 0,1kGy; 0,2kGy; 0,3kGy; 0,4kGy e 0,5kGy. Os melões MP dos experimentos 3 e 4, após o processamento, foram imersos durante 1 minuto a 5ºC em: água (testemunha); vanilina (1000 mg L-1 e 2000 mg L-1); ácido cinâmico (148,16 mg L-1 e 296,32 mg L-1) e outros dois tratamentos consistiram em aplicação de vapor de ácido cinâmico (148,16 mg L-1 e 296,32 mg L-1) nos melões MP dentro da embalagem (bandejas de polipropileno termo seladas com filme de polipropileno). O armazenamento refrigerado foi realizado durante 10 dias 5±1ºC e 85-90% UR (experimentos 1 e 2) e à 5±1ºC e 85-95% UR (experimentos 3 e 4). As alterações na qualidade foram detectadas por meio das análises: perda de massa fresca, conservação pós-colheita, firmeza, pH, acidez titulável, sólidos solúveis, teores de açúcares redutores e redutores totais, ácido ascórbico, vitamina C, taxa respiratória, produção de etileno... (Resumo completo, clicar acesso electrônico abaixo) / Abstract: The aim of this research was to evaluated the effects of the gamma radiation and the natural antimicrobials in the conservation of fresh-cut melon storaged under refrigeration. Four experiments were accomplished: 1 and 2 - the varieties used were 'Cantaloupe' and 'Pele de Sapo' from Baraúna/RN and Juazeiro/BA, respectively; 3 and 4 - the varieties used were 'Cantaloupe' and 'Gália' from Cartagena (Spain). After harvesting, fruits from experiment 1 and 2 were sent to the Laboratory of Fruits and Vegetables at the University of Sao Paulo State (UNESP - Botucatu/SP). Fruits from experiment 3 and 4 were sent to the Postharvest and Refrigeration Group at the Technical University of Cartagena/Spain. After the manual processing (cut in trapezoidal sections) the fresh-cut melons of the experiment 1 and 2 were conditioned in polystyrene trays involved by polyethylene film and irradiated with doses: 0,0kGy; 0,1kGy; 0,2kGy; 0,3kGy; 0,4kGy and 0,5kGy. After processing, fresh-cut melons from experiment 3 and 4 were immersed for 1 min at 5ºC in water (control); vanillin (1000 mg L-1 and 2000 mg L-1); cinnamic acid (148,16 mg L- 1 and 296,32 mg L-1). Two additional treatments consisted on the application of cinnamic acid vapor (148,16 mg L-1 e 296,32 mg L-1) on fresh-cut melons within the packages (polypropylene trays heat-sealed with polypropylene). The storage was realized during 10 days in a cold camera to 5±1ºC and 85-90% HR (experiment 1 and 2) and to 5±1ºC and 85- 95% HR (experiment 3 and 4). The quality alterations were detected through the analyses: loss of fresh mass, postharvest conservation, firmness, pH, acidity titratable, soluble solids, reducing and total reducing sugar content, ascorbic acid, vitamin C, respiration rate, ethylene production, gas composition (CO2 and O2), enzymes activity (peroxidase, polygalacturonase and pectinmethylesterase), antioxidant... (Complete abstract click electronic access below) / Doutor

Thesis (Ph. D. Agriculture (Plant Protection)) -- University of Limpopo, 2013 / Global withdrawal of synthetic fumigant and non-fumigant nematicides due to their ecounfriendly impacts and high toxicity to non-target organisms, respectively, increased the research and development of alternatives for managing population densities of plantparasitic nematodes, particularly the root-knot (Meloidogyne species) nematodes. Although Meloidogyne species had been managed using genotypes that are resistant to plant-parasitic nematodes in various crops, various challenges negate the available or introgressed nematode resistance. In tomato (Solanum lycopersicum) production, nematode races and instability of nematode resistant genotypes under certain conditions necessitated the continued research and development of alternatives since most of the existing commercial tomato cultivars are highly susceptible to various biological races of Meloidogyne species. The aim of the study was to research and develop appropriate dosages of two phyto- nematicides which could be applied through drip irrigation system in open field tomato production systems, while the specific objectives were to: (1) determine whether a computer-based model could provide nonphytotoxic concentrations to tomato plants using fresh fruits of wild watermelon (Cucumis africanus) and wild cucumber (C. myriocarpus) under greenhouse conditions, (2) determine whether computer-based concentrations from the two plant species when using dried fruits would be less phytotoxic and more suppressive to nematodes, (3) investigate application time intervals for the two products, (4) determine responses of plant growth in tomato and nematode suppression in respect to the derived dosages, and and (5) validate dosages of fermented crude extracts from the two plant species with respect to plant growth of tomato and suppression of nematode numbers. xxxiii Greenhouse, microplot and field studies were set to test the hypotheses intended to achieve the stated objectives, with reliability of measured variables being ensured by using statistical levels of significance (P ≤ 0.05) and coefficients of determination (R2), while validity was ensured by conducting experiments at the same location over two seasons and/or by setting up factorial treatments. Firstly, fermented plant extracts of fresh fruits from C. africanus and C. myriocarpus consistently reduced population densities of Meloidogyne species by 80-92% and 50-90%, respectively. Tomato plants were highly sensitive to the two products as shown by the total degree of sensitivities (Σk) and biological index of 0 and 3, respectively. Also, the mean concentration stimulation range (MCSR) of 11% and 7% concentrations, respectively, attested to this phytotoxicity. Secondly, fermented crude extracts of dried fruits from C. africanus and C. myriocarpus also reduced population densities of Meloidogyne species by 78-97% and 87-97%, respectively. Tomato plants were highly tolerant to the two products in dried form as shown by the total degree of sensitivities (Σk) and biological index of 4 and 3, respectively. The MCSR values for C. africanus and C. myriocarpus dried fruits on tomato were 2.64% and 2.99%, respectively, which for the purpose of this study were individually adjusted to 3%, which translated to 36 L undiluted material/ha of 4 000 tomato plants. In subsequent studies, 3% concentration was used as the standard, along with double strength concentration, namely, 6% concentration. Thirdly, the MCSR values derived in Objective 4, namely 3% and 6% concentration for both Cucumis species using the CARD model were used in the optimisation of application time interval using the innovative concept of weeks (0, 1, 2, 3 and 4) in a 30-day month period. Application time interval for 3% and 6% concentrations of C. africanus fruits was xxxiv optimised at 2.40 and 2.61 weeks in a 30-day month period, respectively, which translated to 18 days [(2.4 weeks/4 weeks) × 30 days] and 20 days [(2.6 weeks/4 weeks) × 30 days], respectively. In contrast, for both concentrations from fermented crude extracts of C. myriocarpus fruits, application time interval was optimised at 16 days for 2.2 and 2.1 weeks, respectively. During optimisation of application frequencies, fermented crude extracts from C. africanus and C. myriocarpus reduced final population densities of M. incognita race 2 by 70-97% and 76-96%, respectively. Fourthly, optimum application intervals (time), allowed computation of dosage, which is a product of concentration and application frequency (dosage = concentration × application frequency). Fifthly, validation of the dosages under open field conditions suggested that 6% × 16-day dosage under crude extracts from C. myriocarpus fruit significantly (P ≤ 0.05) improved growth of tomato plants when compared with those of either 0% (untreated control) or 3% at 16 days. In contrast, dosages of C. africanus fruit at two application frequency had no effect on growth of tomato plants – suggesting that either of the dosages was suitable for use in tomato production since both reduced nematode numbers. During validation, the materials reduced nematode numbers by margins similar to those observed previously under other environments. In conclusion, crude extracts of the two Cucumis species have stimulatory concentrations which have potential similar reductive effects on population densities of Meloidogyne species and could serve as botanical nematicides. However, since plant responses to the two products differed in terms of their respective dosages and active ingredients, it implied that for further improvement of the two, the overriding focus should be on their interaction with the protected plants and nematode numbers. Ideally, future research xxxv should include environmental impact studies, especially on the influence of the products fruit quality of tomato, earthworms, fish and bees.

Thesis (Ph. D. Agriculture (Plant Protection)) -- University of Limpopo, 2013 / Global withdrawal of synthetic fumigant and non-fumigant nematicides due to their ecounfriendly impacts and high toxicity to non-target organisms, respectively, increased the research and development of alternatives for managing population densities of plantparasitic nematodes, particularly the root-knot (Meloidogyne species) nematodes. Although Meloidogyne species had been managed using genotypes that are resistant to plant-parasitic nematodes in various crops, various challenges negate the available or introgressed nematode resistance. In tomato (Solanum lycopersicum) production, nematode races and instability of nematode resistant genotypes under certain conditions necessitated the continued research and development of alternatives since most of the existing commercial tomato cultivars are highly susceptible to various biological races of Meloidogyne species. The aim of the study was to research and develop appropriate dosages of two phyto- nematicides which could be applied through drip irrigation system in open field tomato production systems, while the specific objectives were to: (1) determine whether a computer-based model could provide nonphytotoxic concentrations to tomato plants using fresh fruits of wild watermelon (Cucumis africanus) and wild cucumber (C. myriocarpus) under greenhouse conditions, (2) determine whether computer-based concentrations from the two plant species when using dried fruits would be less phytotoxic and more suppressive to nematodes, (3) investigate application time intervals for the two products, (4) determine responses of plant growth in tomato and nematode suppression in respect to the derived dosages, and and (5) validate dosages of fermented crude extracts from the two plant species with respect to plant growth of tomato and suppression of nematode numbers. xxxiii Greenhouse, microplot and field studies were set to test the hypotheses intended to achieve the stated objectives, with reliability of measured variables being ensured by using statistical levels of significance (P ≤ 0.05) and coefficients of determination (R2), while validity was ensured by conducting experiments at the same location over two seasons and/or by setting up factorial treatments. Firstly, fermented plant extracts of fresh fruits from C. africanus and C. myriocarpus consistently reduced population densities of Meloidogyne species by 80-92% and 50-90%, respectively. Tomato plants were highly sensitive to the two products as shown by the total degree of sensitivities (Σk) and biological index of 0 and 3, respectively. Also, the mean concentration stimulation range (MCSR) of 11% and 7% concentrations, respectively, attested to this phytotoxicity. Secondly, fermented crude extracts of dried fruits from C. africanus and C. myriocarpus also reduced population densities of Meloidogyne species by 78-97% and 87-97%, respectively. Tomato plants were highly tolerant to the two products in dried form as shown by the total degree of sensitivities (Σk) and biological index of 4 and 3, respectively. The MCSR values for C. africanus and C. myriocarpus dried fruits on tomato were 2.64% and 2.99%, respectively, which for the purpose of this study were individually adjusted to 3%, which translated to 36 L undiluted material/ha of 4 000 tomato plants. In subsequent studies, 3% concentration was used as the standard, along with double strength concentration, namely, 6% concentration. Thirdly, the MCSR values derived in Objective 4, namely 3% and 6% concentration for both Cucumis species using the CARD model were used in the optimisation of application time interval using the innovative concept of weeks (0, 1, 2, 3 and 4) in a 30-day month period. Application time interval for 3% and 6% concentrations of C. africanus fruits was xxxiv optimised at 2.40 and 2.61 weeks in a 30-day month period, respectively, which translated to 18 days [(2.4 weeks/4 weeks) × 30 days] and 20 days [(2.6 weeks/4 weeks) × 30 days], respectively. In contrast, for both concentrations from fermented crude extracts of C. myriocarpus fruits, application time interval was optimised at 16 days for 2.2 and 2.1 weeks, respectively. During optimisation of application frequencies, fermented crude extracts from C. africanus and C. myriocarpus reduced final population densities of M. incognita race 2 by 70-97% and 76-96%, respectively. Fourthly, optimum application intervals (time), allowed computation of dosage, which is a product of concentration and application frequency (dosage = concentration × application frequency). Fifthly, validation of the dosages under open field conditions suggested that 6% × 16-day dosage under crude extracts from C. myriocarpus fruit significantly (P ≤ 0.05) improved growth of tomato plants when compared with those of either 0% (untreated control) or 3% at 16 days. In contrast, dosages of C. africanus fruit at two application frequency had no effect on growth of tomato plants – suggesting that either of the dosages was suitable for use in tomato production since both reduced nematode numbers. During validation, the materials reduced nematode numbers by margins similar to those observed previously under other environments. In conclusion, crude extracts of the two Cucumis species have stimulatory concentrations which have potential similar reductive effects on population densities of Meloidogyne species and could serve as botanical nematicides. However, since plant responses to the two products differed in terms of their respective dosages and active ingredients, it implied that for further improvement of the two, the overriding focus should be on their interaction with the protected plants and nematode numbers. Ideally, future research xxxv should include environmental impact studies, especially on the influence of the products fruit quality of tomato, earthworms, fish and bees.

Light and phytohormones, such as cytokinins, have been known to play a pivotal role in numerous physiological processes in plant cells. Previous work in our laboratory has revealed the light- and cytokinin- modulated changes both in the levels of specific tRNA species and their modified nucleotide contents, in addition to the characterization of specific tRNAs and tRNA genes from higher plants. The plant hormone cytokinin, which is of particular interest to us has been implicated to be involved in processes such as induction of cell division, plastid biogenesis and delay of senescence. Ongoing work in our laboratory also points towards the role of Ca2+ as a second messenger in cytokinin mediated gene expression. With the objective of isolation of specific tRNA genes which could then be used as probes to study the light- and phytohormone- induced changes in the levels of respective functional mature tRNAs, a previously isolated clone containing a 6.6kb insert that hybridized with 3 end labeled cucumber total cellular tRNA was sequenced by the dideoxy chain termination method. Sequence analysis of the 6.6 kb DNA fragment has revealed a chloroplast genome DNA fragment containing the trnNGUU and trnRACG genes in addition to the genes coding for the ribosomal RNAs 4.5S, 5S and 23S as well as the protein coding genes ccsA (cytochrome c-synthesis) and ndhD(NADH plastoquinone oxidoreductase).These genes were found to be arranged in the order-23S-4.5S-5S-trnRACG-trnNGUU-ccsA-ndhD. This shows a divergence from the gene organization in the completely sequenced chloroplast genomes of other higher plant species such as tobacco, maize, rice and Arabidopsis, especially with regard to the absence of a highly conserved trnLUAG gene that has been shown to be present in the trnNGUU-ndhD intergenic region. The cucumber chloroplast trnNGUU and trnRACG genes have shown very high homology (>90%) whereas ccsA and ndhD show 50-61% similarity to corresponding genes from chloroplast genomes of other plant species. The relative levels of tRNAArg and tRNAAsn were determined by Northern analysis using the tRNA gene probes, in etiolated excised cucumber cotyledons treated with light or phytohormones, such as cytokinin (BA) and auxin (2,4-D). Light and phytohormones were found to significantly increase the levels of tRNAArg unlike in the case tRNAAsn where no significant changes in the levels were observed. This result points towards the regulation of relative levels of specific tRNA species by light and cytokinin so as to match the codon usage of the mRNA population during light- and cytokinin- induced plant development in cucumber. Northern analyses were also performed to monitor the relative transcript levels of the plastid encoded ccsA and ndhD in etiolated excised cucumber cotyledons treated with light or phytohormones. ccsA transcript levels were found to be significantly reduced in auxin treated cucumber cotyledons where as exogenous application of cytokinin to either dark-grown or light exposed cotyledons did not seem to have any pronounced effect. ndhD transcripts were found to be up-regulated by cytokinin treatment or light exposure in comparison to un-treated controls probably indicating a point of overlap in the light/ cytokinin mediated signal transduction pathways. Auxin treatment on the other hand was found to down-regulate ndhD transcript levels also. Recent studies from our laboratory have demonstrated the involvement of a calcium-dependent protein kinase(CDPK) in the cytokinin-signal transduction pathway associated with the induction of pathogenesis-related proteins (chitinase and β 1-3 modulation of nuclear-encoded CDPK transcripts in response to light and exogenously added phytohormones such as cytokinins and auxin. Towards this end, partial CDPK cDNAs were generated from Cucumis Sativus by RT-PCR using degenerate primers designed based on the conserved regions of the known CDPK proteins available in the database, cloned in pGEM-T and sequenced. Sequence analysis of twenty partial cDNA clones revealed the presence of at least four CDPK isoforms in Cucumis sativus (CuCDPK 1-4). Of the four partial CDPK cDNAs, the tissue-specific expression level of CuCDPK3 was studied using the highly sensitive Taqman Analysis (Quantitative RT-PCR). The results obtained indicate that, in excised dark-grown cucumber cotyledons light and cytokinin were found to up-regulate the levels of CuCDPK3 unlike auxin, which was found to have no significant effect. In cucumber hypocotyls, which had the highest levels of CuCDPK3, light was found to have a down-regulatory effect whereas cytokinin and auxin did not bring about any significant changes in the levels of CuCDPK3. In cucumber root tissue, both light and cytokinin were found to have a down-regulatory effect on the levels of CuCDPK3, unlike auxin. The southern analysis of cucumber genomic DNA revealed a CDPK multi-gene family in cucumber. Since cytokinins have been known to play a role in both etioplast and chloroplast biogenesis and since various groups have recently reported the presence of higher plant homologues of bacterial cell-division protein FtsZ and the requirement of plant nuclear-encoded FtsZs for plastid division, efforts were also made to isolate and to study the expression of cucumber FtsZ in dark-grown cucumber cotyledon tissue treated exogenously with light/phytohormones. Towards this end, a partial FtsZ cDNA was generated from cucumber by RT-PCR using degenerate primers designed based on conserved regions of known plant FtsZ proteins. Results of the Taqman Analysis indicate that cytokinin, unlike auxin, mimics the action of light by increasing the levels of CuFtsZ transcripts in dark-grown cotyledon tissue suggesting the involvement of FtsZ in cytokinin-induced plastid-biogenesis.

Currently there is no control of bacterial wilt disease, Erwinia tracheiphila, in susceptible cucurbit crops, once infection of the plant occurs. Conventional and organic production systems rely on insecticide applications to kill the vectors, striped and spotted cucumber beetles, Acalymma vittatum and Diabrotica undecimpunctata, respectively, prior to transmission of the pathogen which indirectly controls the disease to some extent. Physical barriers such as row covers are used to exclude the vectors from plants prior to flowering; however, pollination requirements expose plants to potential infection. Experimental field plots were developed to test various enhanced organic production systems in an effort to increase productivity of the "Athena" variety cantaloupe melon crop, Cucumis melo, which is highly susceptible to bacterial wilt infection. The rotations included enhanced duration row cover applications as well as season long covering of the crop and application of bumble bee hives for pollination. The most successful enhanced production method included the removal of row covers and application of organic pesticides during flowering and recovering the crop until the end of the season. In this scenario, reduction in the cost of pesticide application and reduced risk due to less exposure to infection are the key enhancements to the system. During pollination, the melon plants are at risk of infection from bacterial wilt because organic production methods cannot include systemic insecticides. Only shorter residual contact insecticides are available, thus exposing the melon plants to vectors after the contact insecticide becomes ineffective. Application of an off-label biocontrol bacterium, Pseudomonas fluorescens A506, found in the organically certified product BlightBan®A506, was found to significantly increase control of Erwinia tracheiphila infection in plants, thereby allowing for increased productivity. Additionally, development of a Real-Time Polymerase Chain Reaction, RT-PCR, primer set and probe improve the detection of Erwinia tracheiphila in melon plants. This new primer set was tested against numerous related and associated pathogens to document the specificity of this particular screening test.

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Two experiments were conducted to find diversity in plant responses to arbuscular mycorrhizal (AM) fungi: positively and negatively/non-responsive combinations. Medic (Medicago truncatula L.) tomato (Solanum esculentum L.), leek (Allium porrum L.) and cucumber (Cucumis sativus L.) were inoculated with Glomus intraradices, Gigaspora margarita and Scutellospora calospora. It was found that soil differences critically affect plant responses to AM fungi. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283734 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Two experiments were conducted to find diversity in plant responses to arbuscular mycorrhizal (AM) fungi: positively and negatively/non-responsive combinations. Medic (Medicago truncatula L.) tomato (Solanum esculentum L.), leek (Allium porrum L.) and cucumber (Cucumis sativus L.) were inoculated with Glomus intraradices, Gigaspora margarita and Scutellospora calospora. It was found that soil differences critically affect plant responses to AM fungi. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283734 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007

Orientador: João Domingos Rodrigues / Banca: Rumy Goto / Banca: Marcos Antonio Bacarin / Resumo: As estrobilurinas são fungicidas com efeitos fisiológicos positivos no rendimento das culturas, devido ao aumento da fotossíntese líquida e melhor balanço hormonal. O boscalida complementa a ação desses fungicidas, seja aplicado alternadamente, seja aplicado em conjunto. E, assim como as estrobilurinas, é um fungicida sistêmico que funciona preventivamente inibindo a germinação de esporos, e possui pouco efeito curativo; portanto, a aplicação preventiva desses produtos traz como benefícios, além de proteger a planta, o de incrementar a produção através de seus benefícios fisiológicos. O presente trabalho teve como objetivo avaliar o efeito da aplicação de piraclostrobina, azoxistrobina e boscalida em pepino japonês (Cucumis sativus L.) enxertado e não enxertado, em condições de ambiente protegido, visando a seus efeitos fisiológicos no metabolismo e desenvolvimento da planta, bem como no aumento da produção e qualidade dos frutos. O experimento foi conduzido em área experimental da Faculdade de Ciências Agronômicas da Universidade Estadual Paulista, Campus de Botucatu-SP em ambiente protegido. O delineamento experimental foi inteiramente casualisado, fatorial 2 x 5, sendo plantas de pepino enxertadas e plantas não enxertadas e 5 tratamentos com fungicidas: testemunha, azoxistrobina 60g ha-1, boscalid 50g ha-1, piraclostrobina 50 g ha-1, boscalid (100g ha-1) + piraclostrobina (50 g ha-1), aplicados 18 dias após o transplante a intervalos de 7 dias, via foliar. O efeito dos tratamentos foi avaliado através das observações das seguintes características: produção de frutos e massa média do fruto, trocas gasosas, índice de clorofila nas folhas e atividade das enzimas peroxidase, superóxido dismutase, catalase e nitrato redutase. Em função dos resultados obtidos, conclui-se que os fungicidas testados apresentam efeitos fisiológicos positivos nas plantas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Strobilurins are fungicides of positive physiological effects on crop yield due to increased net photosynthesis and improved hormone balance. Boscalid complements the action of these fungicides, applied alternately or together. And, as the strobilurins, is a systemic fungicide that works preemptively inhibiting germination of spores, and has little curative effect; therefore the preventive application of these products protect the plant and increases production through its physiological benefits. This experiment aimed to evaluate the effect of applying pyraclostrobin, azoxystrobin and boscalid in japanese cucumber (Cucumis sativus L.) grafted and non-grafted, in greenhouse conditions, aiming to their physiological effects on metabolism and plant development, as well as increased production and fruit quality. The study was conducted in an experimental area which belongs to the School of Agronomical Sciences (FCA), São Paulo State University (UNESP), Campus Botucatu, in greenhouse conditions. Experimental design was completely randomized, 2 x 5 factorial arrangement, including grafted cucumber plants and non-grafted plants and 5 fungicide treatments: control, azoxystrobin 60g ha-1, boscalid 50g ha-1, pyraclostrobin 50 g ha-1, boscalid (100g ha-1) + pyraclostrobin (50 g ha-1), sprayed 18 days after transplant (DAT) at 7-day intervals into leaves. The effect of the treatments was evaluated through observations of the following: fruit production and fruit weight, gas exchanges, leaf chlorophyll content and activity of peroxidase, superoxide dismutase, catalase and nitrate reductase. Based on these results, we conclude that the tested fungicides have positive physiological effects on Japanese cucumber plants grafted and non-grafted, and these effects were more evident in grafted plants, in which all fungicides increased yield, nitrate reductase activity (in early development) also antioxidative... (Complete abstract click electronic access below) / Mestre

PEREIRA FILHO, João Valdenor. Cultivo do melão sob diferentes frequências de irrigação e parcelamento da adubação nitrogenada no Vale do Curu, CE. 2012. 94 f. : Dissertação (mestrado) - Universidade Federal do Ceara, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola, Fortaleza-CE. 2012. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-07-08T13:32:46Z No. of bitstreams: 1 2012_jvpereirafilho.pdf: 1490568 bytes, checksum: 2ad2bdac81eee74a87509a740c9e0911 (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-07-08T13:34:30Z (GMT) No. of bitstreams: 1 2012_jvpereirafilho.pdf: 1490568 bytes, checksum: 2ad2bdac81eee74a87509a740c9e0911 (MD5) / Made available in DSpace on 2016-07-08T13:34:30Z (GMT). No. of bitstreams: 1 2012_jvpereirafilho.pdf: 1490568 bytes, checksum: 2ad2bdac81eee74a87509a740c9e0911 (MD5) Previous issue date: 2012 / The melon has recognized the socio-economic status in northeastern Brazil, and the studies that define the appropriate irrigation frequency and timing of nitrogen application the melon are essential, as they can considerably improve the yield and fruit quality. Thus, the experiment was conducted during the months from July to October 2011 with the objective of evaluating the behavior of melon grown under different irrigation frequencies and under the effect of split nitrogen fertilization at different times. The study was conducted at the Fazenda Experimental Vale Curu, Pentecoste, Ceará, Brazil. The experimental design was that of randomized blocks with split plots. The treatments were combinations of six irrigation frequencies: F1 – 2.0 day-1; F2 – 1.0 day-1; F3 - 0,5 day-1; F4 - 0,3 day-1; F5 - 0,25 day-1 e F6 - 0,2 day-1 and four ways of applying 90 kg N ha-1 : 100% at 20 days after sowing (DAS) - (0-100-0-0); 30% at sowing and 70% at 20 DAS - (30-70-0-0); 30% at sowing, 30% at 20 DAS and 40% at 35 DAS (30-30-40-0); 20% at sowing, 30% at 20 DAS, 30% at 35 DAS and 20% at 50 DAS (20-30-30-20). It was found that the more frequent irrigations, as well as the application of nitrogen topdressing up to 50 DAS result in better culture growth, which greater main stem length, more leaves, greater stem diameter, more dry leaf mass, more dry stem mass and more total dry mass. As for the physiological characteristics (stomatal conductance, photosynthesis and transpiration) daily irrigation frequency (F2) produced the best results. There was no significant interference of the photosynthesis varable on the effects of split nitrogen fertilization. Regarding the characteristics of fruit quality, the highest frequencies of irrigation promoted the best of fruit by the Brix and total acidity criteria. The pH of the fruits, however, was not influenced by irrigation. Under water deficit conditions the fruits had the highest rate of maturation (rate). We observed larger fruit and better fruit shape index, larger mean weight and higher total yield potential under high frequency irrigation. The highest yield potential was obtained with the F2 treatment (daily irrigation) with 18846.80 kg ha-1. As to the partitioning of the nitrogen fertilizer, the topdressing application of N fertilizer up to 35 DAS provided fruits with the largest average mass. / O meloeiro possui relevante importância sócio-econômica no Nordeste brasileiro, sendo que os estudos que definem a frequência de irrigação e a época de aplicação da adubação nitrogenada adequadas à cultura são fundamentais, podendo melhorar consideravelmente o rendimento e a qualidade dos frutos. Desse modo, o experimento foi conduzido durante os meses de julho a outubro de 2011, com o objetivo de avaliar o comportamento do meloeiro cultivado sob diferentes frequências de irrigação e parcelamentos da adubação nitrogenada em diferentes épocas. O trabalho foi realizado na Fazenda Experimental Vale do Curu, Pentecoste, Ceará, Brasil. O delineamento experimental foi o de blocos ao acaso com parcelas subdivididas. Os tratamentos consistiram da combinação de seis frequências de irrigação: F1 - 2,0 dia-1; F2 - 1,0 dia-1; F3 - 0,5 dia-1; F4 - 0,3 dia-1; F5 - 0,25 dia-1 e F6 - 0,2 dia-1 e quatro aplicações parceladas da adubação nitrogenada recomendada de 90 kg ha-1: N1 - 100% aos 20 dias após a semeadura (DAS) - (0-100-0-0); N2 - 30% na semeadura e 70% aos 20 DAS - (30-70-0-0); N3 - 30% na semeadura, 30% aos 20 DAS e 40% aos 35 DAS (30-30-40-0); N4 - 20% na semeadura, 30% aos 20 DAS, 30% aos 35 DAS e 20% aos 50 DAS (20-30-30-20). Verificaram-se que as aplicações de água com maior frequência, assim como a aplicação da adubação nitrogenada em cobertura até 50 DAS propiciaram melhor desenvolvimento à cultura, as quais possuem maior comprimento da haste principal, número de folhas, diâmetro do caule e matéria seca da parte aérea (folhas, hastes). Quanto às características fisiológicas (condutância estomática, fotossíntese e transpiração) a frequência de irrigação diária (F2) propiciou os melhores resultados. Não houve efeito significativo na variável fotossíntese com o parcelamento da adubação nitrogenada. Quanto às características de qualidade dos frutos, as maiores frequências de irrigação propiciaram frutos de melhor qualidade quanto ao sólidos solúveis totais e acidez total; no entanto, o pH dos frutos não foi influenciado pelo manejo da irrigação. Sob condições de déficit hídrico os frutos apresentaram maior índice de maturação (ratio). Verificaram-se maiores dimensões e índice de formato dos frutos, massa média e potencial produtivo total sob altas frequências de irrigação. O maior potencial produtivo foi obtido com o tratamento F2 (frequência de irrigação de um dia) com 18.846,80 kg ha-1. Quanto ao parcelamento da adubação nitrogenada, a aplicação em cobertura do N até 35 DAS apresentou frutos com maior massa média (933,13 g fruto-1).

MOREIRA, Samira Pereira. Avaliação da qualidade e segurança de melão minimamente processado revestido em matriz de quitosana adicionada de compostos bioativos microencapsulados extraídos de subprodutos de acerola. 2014. 166 f. Dissertação (Mestrado em Ciência e Tecnologia de Alimentos)-Universidade Federal do Ceará, Fortaleza, 2014. / Submitted by Vitor Campos (vitband@gmail.com) on 2016-10-03T23:19:30Z No. of bitstreams: 1 2014_dis_spmoreira.pdf: 2559693 bytes, checksum: d4f3061bd25a32ab80831f9b6ec70674 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2016-10-04T23:33:53Z (GMT) No. of bitstreams: 1 2014_dis_spmoreira.pdf: 2559693 bytes, checksum: d4f3061bd25a32ab80831f9b6ec70674 (MD5) / Made available in DSpace on 2016-10-04T23:33:53Z (GMT). No. of bitstreams: 1 2014_dis_spmoreira.pdf: 2559693 bytes, checksum: d4f3061bd25a32ab80831f9b6ec70674 (MD5) Previous issue date: 2014 / The minimal processing of fruits and vegetables offers the consumer food fresh and practicality. However, these products rapidly lose quality after processing due to physical changes and their consequential biochemical reactions that can reduce the nutritional value and favours besides the growth of deteriorant and pathogenic microorganisms. Thus, this study aimed to develop a system of active packaging, consisting of an microencapsulated antimicrobial edible coating using chitosan added with bioactive compounds extracted from byproducts of processing of acerola (Malpighia emarginata D.C.) for minimally processed melon to maintain the quality and microbiological safety of this product. The parameters extraction of bioactive compounds of lyophilized byproducts (seed, peel and fibers) were optimized as the rotation speed, extraction time, extraction solution and by proportion: extraction solution. The extract showed high content of antioxidants, especially polyphenols. The coating was produced from the 1:1 mixture (v / v) solution of chitosan and 1% ethanolic extract of bioactive compounds, and chitosan itself as the encapsulating material. Two treatments (coated and uncoated melons) each 3 days during 12 days of storage at 10˚C ± 1 were evaluated as attributes of quality, bioactive compounds, total antioxidant activity, spoilage and pathogenic microorganisms (Salmonella spp and Listeria monocytogenes). The results showed that the coating samples provided the melons minor loss of firmness and weight, increased the content of yellow flavonoids and total extractable polyphenols, consequently high total antioxidant activity when compared to control cubes. Moreover, the coating showed antimicrobial activity against bacteria (mesophilic, psicotrophic and lactic), molds and yeasts in coated fruits. The novel product is according to RDC ANVISA 12˚ whose recommendation for fresh fruits must be absence of Salmonella spp in 25 g. Therefore, this coating is a viable alternative for maintain the quality of minimally processed melons , since it provided better nutrition by maintaining bioactive fruit compounds, the safety, beyond the scope of the life of the product. / O processamento mínimo de frutas e hortaliças oferece ao consumidor alimentos frescos e práticos. Contudo, estes produtos perdem rapidamente a qualidade após o processamento devido às alterações físicas e suas conseqüentes reações bioquímicas reduzindo o valor nutricional, além de favorecer o crescimento de microrganismos patogênicos. Assim, este trabalho objetivou desenvolver um sistema de embalagem ativa, consistindo de um revestimento comestível antimicrobiano para revestimento de melão minimamente processado à base de quitosana incorporado de compostos bioativos microencapsulados extraídos de subprodutos do processamento de acerola (Malpighia emarginata D.C) visando a manutenção da qualidade e segurança microbiológica do produto. Os parâmetros de extração dos compostos bioativos dos subprodutos liofilizados (semente, película e fibras) foram otimizados quanto a velocidade de rotação, tempo de extração, solução extratora e proporção subprodutos : solução extratora . O extrato apresentou alto teor de compostos antioxidantes, principalmente polifenóis. O revestimento utilizado nesse estudo foi produzido a partir da mistura na proporção 1:1 (v/v) de solução de quitosana 1% e extrato etanólico de compostos bioativos, tendo a própria quitosana como material encapsulante. Dois tratamentos (melões revestidos e não revestidos) foram avaliados a cada 3 dias durante 12 dias de armazenamento a 10˚C ± 1 quanto aos atributos de qualidade, compostos bioativos, atividade antioxidante total, microorganismos deteriorantes e patogênicos (Salmonella spp e Listeria monocytogenes). Os resultados demonstraram que o revestimento proporcionou aos melões menor perda de firmeza e de peso, além de maiores conteúdos de flavonóides amarelos e de polifenóis extraíveis totais, consequentemente elevada atividade antioxidante total quando comparado ao controle. Foi obsevado ação antimicrobiana contra bactérias (mesófilas, psicotróficas e láticas), bolores e leveduras nos frutos revestidos. O produto apresentou-se em conformidade com a RDC n˚ 12 da ANVISA cuja recomendação para frutas in natura é de ausência de Salmonela spp em 25 g. Portanto, este revestimento é uma alternativa viável para a manutenção da qualidade de melões minimamente processados, uma vez que proporcionou a melhoria nutricional, através da manutenção de compostos bioativos da fruta a segurança, além da extensão da vida útil desse produto.