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Orientador: Aloisio Costa Sampaio / Banca: Terezinha de Fátima Fumis / Banca: Jaime Duarte Filho / Resumo: O presente trabalho teve por objetivo, obter maiores informações sobre o desenvolvimento de quatro cultivares de morangueiro (Dover, Oso Grande, Camarosa e Sweet Charlie), na região de Bauru - SP, submetidos a sistemas fitossanitários alternativos, como ferramenta na Produção Integrada do Morangueiro (PIMO). Avaliou-se aspectos de produtividade (peso e número de frutos); qualidade (teor de sólidos solúveis totais, acidez titulável, pH, vitamina C e textura) e monitoramento de pragas e doenças. O plantio foi realizado em abril de 2005 sobre plástico preto, no espaçamento de 25 x 25 cm, totalizando-se 20 plantas por parcela. O delineamento estatístico foi em blocos casualizados utilizando-se um esquema fatorial em parcelas subdivididas, no qual o fator principal conteve dois modelos de tratamentos fitossanitários e para o fator secundário, as quatro cultivares de morangueiro. Nos dois modelos de tratamentos foram utilizados agroquímicos convencionais da grade PIF para Morango na fase vegetativa (abamectina e tebuconazol), diferenciando-se para a fase reprodutiva; Modelo PIF 1: tratamento com calda viçosa, super magro, Microgeo (2%) e enxofre e Modelo PIF 2: tratamento com calda bordalesa, super magro, éster de ácido graxo (GOC 109) (5%) e enxofre. Os dados obtidos foram submetidos à análise de variância e as médias comparadas através do Teste de Tukey a 5% de probabilidade. A cultivar Dover apresentou maior produtividade média e número médio de frutos independente do sistema de produção; textura mais firme e menor ratio (sabor) indicando maior aptidão para a indústria. A XI cultivar Oso Grande destacou-se positivamente na produção de frutos graúdos, firmeza e sabor, aspectos importantes para o consumidor e comercialização. Sweet Charlie apresentou excelente características de sabor e vitamina C... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present work had for objective, to obtain more information about the development of four strawberry cultivars ( Dover, Oso Grande, Camarosa and Sweet Charlie), in Bauru - SP, submitted to alternative phytosanitary systems, as tool for the Integrated Strawberry Production. Aspects of productivity (weigh and number of fruits); quality (total soluble solids, titrable acidity, pH, vitamin C and firmness) and pest and disease monitoring were evaluated. The planting was accomplished in April of 2005 over mulching, the spacing of 25 x 25 cm was adopted being totaled 20 plants by plot. Experimental design used was of randomized blocks in factorial scheme of split plots with the main factor contained two models of phytosanitary treatment and for the secondary factor, the four strawberry cultivars. Conventional agrochemicals (abamectin and tebuconazol) registered for this culture in Brazil, were used for both models of treatment, in the vegetative phase. For the reproductive phase; Model PIF 1: treatment with Viçosa mixture, biofertilizer Supermagro, Microgeo (2%) and sulfur; and Model PIF 2: treatment with Bourdeaux mixture, biofertilizer Supermagro, fatty acid ester (GOC 109) (5%) and sulfur. The data were submitted to a variance analysis and the average compared to Tukey's Test at 5% of probability. 'Dover' presented larger medium productivity and medium number of fruits independent of the production system; firmer texture and smaller ratio (flavor) indicating larger aptitude for the industry. 'Oso Grande' stood out positively in the production of great fruits, firmness and flavor, important aspects for the consumer and commercialization. ‘Sweet XIII Charlie' presented excellent flavor characteristics and vitamin C, demonstrating an aptitude for in natura consumption. There were not significant differences among the employed production... (Complete abstract click electronic access below) / Mestre

Orientador: Erasmo José Paioli Pires / Resumo: tratamentos. Em todos os experimentos o delineamento experimental foi o de blocos ao acaso, com 6 repetições e 2 cachos por parcela. A coleta dos cachos foi realizada quando o tratamento testemunha atingiu teor de sólidos solúveis totais mínimo de 14ºBrix. Para cada cacho foram avaliados: massa, comprimento e largura dos cachos, bagos e engaços; relação comprimento/largura dos bagos; número de bagos e número de sementes por bago. Para cada parcela foram realizadas análises de teor de sólidos solúveis totais, acidez total titulável e pH do mosto de 100 bagos. Pelos resultados obtidos, verificou-se que para o cultivar Vênus, o thidiazuron apresentou como principal efeito o aumento do número de bagos. O ácido giberélico, quando aplicado após o florescimento, aumentou a massa dos cachos; a massa e o comprimento dos bagos; e reduziu o número de sementes-traço. Os maiores aumentos das dimensões dos bagos foram obtidos quando realizaram-se duas aplicações. Houve efeito sinérgico entre ácido giberélico e thidiazuron, em aplicações pós-florescimento, incrementando a massa, o comprimento e o número dos bagos. Os melhores resultados, em aplicações combinadas, foram verificados quando realizaram-se duas aplicações de ácido giberélico, com thidiazuron na dose de 5mg.L-1. O thidiazuron, em aplicações pósflorescimento, reduziu o teor de sólidos solúveis totais, principalmente quando associado ao ácido giberélico. Para o cultivar Centennial Seedless, os melhores resultados, foram verificados para aplicações de thidiazuron 10mg.L-1 ou ácido giberélico 30mg.L-1, aos 14 dias após o florescimento, levando ao aumento da massa dos cachos; da massa e largura dos bagos; e da massa dos engaços. Para este cultivar, o thidiazuron também reduziu o teor de sólidos...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: With the objective of studying the effects of thidiazuron and gibberellic acid on the cluster characteristics of the vine cultivars Venus, Centennial Seedless and Niagara Rosada, three experiments were carried out, for each cultivar, in commercial vineyards at different regions of São Paulo State. For the first trial, carried out in 1999, thidiazuron at 5 or 10mg.L-1 and gibberellic acid were applied, associated or not, with all possible combinations of three development stages: before bloom, at full bloom and 14 days after full bloom, totalizing 36 treatments. The following doses of gibberellic acid were applied: 40mg.L-1 for Venus cultivar, 30mg.L-1 for Centennial Seedless cultivar, and 100mg.L-1 for Niagara Rosada cultivar. In the second trial, carried out in 2000, the growth regulators doses were the same of those in the first one, excepted that of GA3 for Niagara Rosada cultivar that was 35mg.L-1. The applications were done 14, 21 and 28 days after full bloom, with all combinations of the three epochs...(Complete abstract, click electronic access below) / Doutor

Made available in DSpace on 2014-06-11T19:26:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-23Bitstream added on 2014-06-13T20:55:02Z : No. of bitstreams: 1 pallamin_ml_me_botfca.pdf: 2330850 bytes, checksum: ede30ea107bdcae07d99d32fdfd9459f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho teve por objetivo, obter maiores informações sobre o desenvolvimento de quatro cultivares de morangueiro (Dover, Oso Grande, Camarosa e Sweet Charlie), na região de Bauru - SP, submetidos a sistemas fitossanitários alternativos, como ferramenta na Produção Integrada do Morangueiro (PIMO). Avaliou-se aspectos de produtividade (peso e número de frutos); qualidade (teor de sólidos solúveis totais, acidez titulável, pH, vitamina C e textura) e monitoramento de pragas e doenças. O plantio foi realizado em abril de 2005 sobre plástico preto, no espaçamento de 25 x 25 cm, totalizando-se 20 plantas por parcela. O delineamento estatístico foi em blocos casualizados utilizando-se um esquema fatorial em parcelas subdivididas, no qual o fator principal conteve dois modelos de tratamentos fitossanitários e para o fator secundário, as quatro cultivares de morangueiro. Nos dois modelos de tratamentos foram utilizados agroquímicos convencionais da grade PIF para Morango na fase vegetativa (abamectina e tebuconazol), diferenciando-se para a fase reprodutiva; Modelo PIF 1: tratamento com calda viçosa, super magro, Microgeo (2%) e enxofre e Modelo PIF 2: tratamento com calda bordalesa, super magro, éster de ácido graxo (GOC 109) (5%) e enxofre. Os dados obtidos foram submetidos à análise de variância e as médias comparadas através do Teste de Tukey a 5% de probabilidade. A cultivar Dover apresentou maior produtividade média e número médio de frutos independente do sistema de produção; textura mais firme e menor ratio (sabor) indicando maior aptidão para a indústria. A XI cultivar Oso Grande destacou-se positivamente na produção de frutos graúdos, firmeza e sabor, aspectos importantes para o consumidor e comercialização. Sweet Charlie apresentou excelente características de sabor e vitamina C... / The present work had for objective, to obtain more information about the development of four strawberry cultivars ( Dover, Oso Grande, Camarosa and Sweet Charlie), in Bauru - SP, submitted to alternative phytosanitary systems, as tool for the Integrated Strawberry Production. Aspects of productivity (weigh and number of fruits); quality (total soluble solids, titrable acidity, pH, vitamin C and firmness) and pest and disease monitoring were evaluated. The planting was accomplished in April of 2005 over mulching, the spacing of 25 x 25 cm was adopted being totaled 20 plants by plot. Experimental design used was of randomized blocks in factorial scheme of split plots with the main factor contained two models of phytosanitary treatment and for the secondary factor, the four strawberry cultivars. Conventional agrochemicals (abamectin and tebuconazol) registered for this culture in Brazil, were used for both models of treatment, in the vegetative phase. For the reproductive phase; Model PIF 1: treatment with Viçosa mixture, biofertilizer Supermagro, Microgeo (2%) and sulfur; and Model PIF 2: treatment with Bourdeaux mixture, biofertilizer Supermagro, fatty acid ester (GOC 109) (5%) and sulfur. The data were submitted to a variance analysis and the average compared to Tukey's Test at 5% of probability. 'Dover' presented larger medium productivity and medium number of fruits independent of the production system; firmer texture and smaller ratio (flavor) indicating larger aptitude for the industry. 'Oso Grande' stood out positively in the production of great fruits, firmness and flavor, important aspects for the consumer and commercialization. Sweet XIII Charlie' presented excellent flavor characteristics and vitamin C, demonstrating an aptitude for in natura consumption. There were not significant differences among the employed production... (Complete abstract click electronic access below)

The Russian wheat aphid (RWA) is a pest of cereals, such as wheat and barley. It feeds on these hosts by injecting saliva into the plants’ phloem tissue and consuming the mixture of saliva and photoassimilates. It has been proposed that the insect’s saliva contains elicitors or virulence factors, which cause the symptoms typically observed in susceptible wheat cultivars. These are leaf rolling, chlorotic streaking, a decrease in yield and death in cases of heavy infestation. In contrast, resistant plants display symptoms typical of defence responses, such as the formation of necrotic lesions and an increase in the expression of pathogenesis related proteins. But, most importantly, RWA feeding on these hosts does not result in their subsequent death. The objectives of the present study are thus to elucidate any putative virulence factors, present in insect saliva, that can result in the breakdown of resistance of cultivars and thus, lack of recognition and/or delayed onset of the plants’ defence responses. Thus, this thesis investigates the RWA on protein level to determine which components of these insects induce the different changes observed in the resistant and susceptible plants. Also, it examines whether or not the biotypes uniquely altered their elicitors in response to selective pressure. In Chapter 1 a brief introduction is presented on the Russian wheat aphid, its distribution and the effects of its feeding on resistant and susceptible wheat cultivars. In Chapter 2 a literature review provides insight on how the Russian wheat aphids feed and survive on wheat. It also outlines the control mechanisms which plants could employ to withstand attack from pests and pathogens. In Chapter 3 proteins were extracted from different parts of two Russian wheat aphid biotypes and separated on high pressure liquid chromatography (HPLC). Two biotypes were selected for the study to provide comparative information on the development of biotypes and/or their virulent elicitors. The presence of the potential elicitors was determined by examining the extent of leaf rolling chlorotic streaking/spots on injected plants’ leaves, determining the activity of defence related enzymes of the injected plants and visualizing the proteins extracted from these plants on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels. This was done in order to examine the plants on phenotypic, enzymatic and proteomic levels, which could confirm the results obtained on three different levels. It was found that resistant cultivars react similarly to the two biotypes, but that the RWA biotypes differ significantly on a protein level. Potential motivations for these variations are discussed. Results presented in this dissertation represent the outcomes of a study conducted from March 2005 to December 2006 in the Department of Genetics, Forestry and Agricultural Biotechnology Institute, University of Pretoria, under the supervision of Prof. A-M Botha-Oberholster. Chapter 3 is being prepared to be submitted for review in Insect Biochemistry and Molecular Biology. / Dissertation (MSc (Plant Genetics))--University of Pretoria, 2008. / Genetics / unrestricted

Maize is the staple food of South Africa and its cultivation covers the largest area of farmland in the country. It plays an important role in the economy as South Africa is consuming 10 million tons of maize per annum. Most South Africans consume maize in some form or another. This commodity has regularly been associated with mycotoxigenic fungi and in some cases their respective mycotoxins. The problem is not only confined to the borders of South Africa but is a concern worldwide. Mycotoxins are known to affect both human and animal health. Some of the most well known mycotoxins are the fumonisins, deoxynivalenol and trichothecenes produced by Fusarium spp., aflatoxins and ochratoxin A produced by mostly Aspergillus spp., as well as patulin and citrinin that are produced by mainly Penicillium spp. Mycotoxins acting together and individually can be hepatotoxic, carcinogenic and teratogenic to humans and animals. The main objective of this study was to screen commercially produced maize cultivars in South Africa that would be either resistant to, or have a slower infection rate when inoculated with the ten selected mycotoxigenic fungi from South African maize. The objective was also to develop a method to detect and identify these mycotoxigenic fungi in the infected maize cultivars, using both basic microbiological and molecular means. These objectives were achieved by a series of experiments that are outlined in the individual chapters. The first part of this study evaluated the level of infestation of fungi in all the commercially produced maize cultivars in South Africa. A basic fungal enumeration and identification was carried out. This allowed the comparison of the in vivo ability of the selected cultivars to endure the natural invasion of mycotoxigenic fungi during cultivation in the same area namely Potchefstroom. As part of the maize evaluation, the cultivars were artificially inoculated with ten selected mycotoxigenic fungi, which consisted of five field fungi nl. Alternaria alternata, Fusarium graminearum, Fusarium verticillioides, Phoma sorghina and Stenocarpella maydis, and five storage fungi nl. Aspergillus flavus, Aspergillus ochraceus, Eurotium repens, Penicillium islandicum and Rhizopus oryzae under storage conditions. The ability of certain maize cultivars to resist the infestation by mycotoxigenic fungi under storage conditions was demonstrated. The second part of this study was to use basic molecular methods to detect and identify the ten mycotoxigenic fungi in the infected maize. This was done by making use of the sequence variations of the internal transcribed spacer (ITS) and D1/D2 regions of the fungal rRNA gene. Results showed that the ITS region gave better differentiation and in most cases allowed identification of the mycotoxigenic fungi. The application of the combined use of microbiological and molecular methodology for the detection and identification of mycotoxigenic fungi in maize by testing laboratories in South Africa were outlined in the final chapter. Implementation of a plan to evaluate maize cultivars in the pre-planting, harvesting and storage phases, can provide a holistic overview of the commodity and can be further implemented in the rural areas. / Dissertation (MSc)--University of Pretoria, 2010. / Microbiology and Plant Pathology / unrestricted

Potato Virus Y (PVY) infection and nitrogen (N) deficiency cause similar symptoms (chlorosis and stunting) on potato foliage. While conventional methods, including ELISA and petiole testing, require destructive sampling and a longer time to diagnose, spectral analysis can be non-destructive, rapid and efficient. Spectral reflectance for potato cultivars representing three market types, chip processing, red-skinned fresh, and fresh and processing russets, were assessed in separate greenhouse trials in response to three N rates (90, 200, and 290 kg/ha) and two PVYN:O infection levels (clean and infected) at 4, 6, and 8 weeks after inoculation (WAI). Normalized Difference Vegetation Index (NDVI) was able to differentiate clean and PVYN:O infected samples of red-skinned and chip processing cultivars, at 4 and 8 WAI, respectively. Overall, cultivars differed in their spectral responses, indicating the importance of studying cultivar-specific spectral responses against PVY infection in future.

The aim of this research was to develop a new harvest maturity index for highly coloured stone fruit that is not affected by seasonal or climatic factors. The judgement of commercial maturity is difficult with some cultivars of stone fruit because they develop intense skin pigmentation several days before they are ripe. Studies of the changes of the physiochemical and physiological parameters associated with ripening confirmed that no single measurement is suitable for the assessment of harvest maturity in the Japanese type plum cultivars(Prunus salicina Lindl). Two distinct patterns of ripening behaviour were identified. The cool storage (0 degrees Centigrade) responses of fruit harvested at three stages of maturity were examined. Total soluble proteins were extracted and separated from fruit during maturation and ripening using 2-dimensional gel electrophoresis. At least three proteins were first detected in fruit at optimum commercial harvest maturity. Since Gulfruby, Beauty and Rubyred (Japanese type plum cultivars) accumulated similar concentrations of aminocyclopropane-1-carboxylic acid(ACC), it was suggested that the suppressed-climacteric phenotype is the result of an impaired ability of the fruit to convert this compound to ethylene / Doctor of Philosophy (PhD) (Ph.D.)