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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

VITIVINICULTURA DE PRECISÃO APLICADA A PRODUÇÃO E QUALIDADE DE UVA PINOT NOIR NO RIO GRANDE DO SUL. / PRECISION VITIVINICULTURE APPLIED TO PRODUCTION AND QUALITY OF PINOT NOIR GRAPES IN RIO GRANDE DO SUL

Zardo, Katia 26 March 2009 (has links)
Precision agriculture applied to vitiviniculture can bring several advantages to vitis crop production with positive effects on grape and wine quality. This study s objective was to put into practice precision vtiticulture, aiming to improve the administration and management of vinifera grapes. This research was carried out in a commercial vitis cropland with 2.4 ha located in Encruzilhada do Sul (RS) close to RS/BR km 471. In this area, sandy clay loam Palleudult soil prevails. Sampling for the purposes for soil characterisation was carried out in 0-0,2 m depth. The soil attributes determined were: pH, SOM, texture, Ca, Mg, Al, N, MO, K and P, and the plant attributes were: productivity, alcoholic potential and tartaric acid, using a 35 X 35m grid. Data were analyzed through geostatistics by interpolation technique of kriging. The data of yield and enological parameters were obtained by manual harvest in georeferenced points. Grape data were collected during the harvest in 2007 and 2008 seasons. Soil and plant data were submitted to statistical analysis and basic geostatistic. Spatial variability of soil chemical attributes in the area behaved in accordance with the nutrient evaluated. pH showed low variability, clay, Ca, Mg, and N, showed median variability while MO, P and K , a high variability was found, and for Al, very high. In 2007 harvest, tartaric acid and alcoholic potential showed low variability, number of bunches per plant and weight per bunch presented median variability while weight per plant showed high variability. In 2008 harvest, alcoholic potential showed low variability, while tartaric acid, number of bunches per plant, weight per plant, weight per bunch and number of gems showed median variability. The 35 X 35 m sampling grid has shown itself adequate for soil attributes excepting clay, which obtained a 30.06 m distance reach. In 2007 harvest, the alcoholic potential was the plant attribute that showed smaller reach n the area, 18.42 m. In 2008 harvest, all the plant attributes studied showed a below 35 m reach. The correlation analysis has revealed itself significant among nitrogen and alcoholic potential in 2007 harvest. In 2008 harvest, phosphorus and potassium showed significant correlation with alcoholic potential. The comparison of the demand for the application of fertilizer at varied rate, with application at steady rate of lime, phosphorus and potassium was based on the soil sampling. In the case of lime, there was a 700 kg saving of it with varied rate application, the same was not observed with phosphorus and potassium, which would increase the product quantity if implemented this way, this happens because the levels of them in the soil are appropriate. The adoption of precision viticulture can help the wine grower to know better and further the productive area, allowing to improve the quality and quantity of the vineyard. / O uso da agricultura de precisão aplicada à vitivinicultura pode trazer benefícios à cultura da vitis e à cadeia produtiva, com reflexos na qualidade da uva e do vinho. O objetivo deste estudo foi aplicar a vitivinicultura de precisão, visando aprimorar a gestão e o manejo de áreas produtivas de uvas viníferas. O estudo foi conduzido em um vinhedo comercial, numa área de 2,4 ha, destinado à fabricação de espumantes situada às margens da RS/BR km 471, em Encruzilhada do Sul-RS. Na área predominam solos classificados como Argissolo Vermelho distrófico. A amostragem para fins de caracterização do solo foram realizadas na profundidade de 0-0,2m. Os atributos de solo determinados foram: pH, SMP, Argila, Ca, Mg, Al, N, MO, K e P, e os atributos de planta foram produtividade, ácido tartárico e potencial alcoólico usando uma malha de amostragem de 35 X 35 m. Os dados foram analisados através da técnica de interpolação geoestatística por krigagem. Os dados de rendimento e parâmetros enológicos foram obtidos por colheita manual em pontos georreferenciados. Os dados de uva foram coletados durante a colheita nas safras 2007 e 2008. Os dados de solo e de planta foram submetidos à analise estatística básica e geoestatistica. A variabilidade espacial dos atributos químicos do solo na área comportou-se de forma distinta de acordo com o nutriente avaliado. O pH apresentou variabilidade baixa, a Argila, o Ca, o Mg, e o N, o apresentaram variabilidade média enquanto que a MO, o K e o P, a variabilidade encontrada foi alta, e para o Al muito alta. Na safra 2007, o ácido tartárico e o potencial alcoólico apresentaram variabilidade baixa, o número de cachos por planta e o peso por cacho apresentaram variabilidade média enquanto que o peso por planta apresentou variabilidade alta. Na safra 2008, o potencial alcoólico apresentou variabilidade baixa, enquanto que o ácido tartárico, o número de cachos por planta, o peso por planta, o peso por cacho e o número de gemas apresentaram variabilidade média. A malha de amostragem de 35X35m se mostrou adequado para os atributos de solo com exceção da argila, que obteve uma distância de alcance de 30,06m. Na safra 2007 o potencial alcoólico foi o atributo de planta que apresentou menor alcance na área, de 18,42 m. Na safra 2008, todos os atributos de planta estudados apresentaram alcance inferior a 35 m. A analise da correlação se revelou significativa entre o nitrogênio e o potencial alcoólico na safra 2007. Na safra 2008, o fósforo e o potássio mostraram correlação significativa com o potencial alcoólico. A comparação da demanda de aplicação de fertilizantes a taxa variada, com a aplicação à taxa fixa de calcário, fósforo e potássio foi feita com base na amostragem de solo. No caso do calcário observou-se uma economia de 700 kg do mesmo com aplicação a taxa variada, o mesmo não foi observado com o fósforo e com o potássio, que aumentaria a quantidade do produto caso fosse aplicado desta forma, isso se dá pelo fato dos teores dos mesmos no solo serem adequados. A adoção da vitivinicultura de precisão pode auxiliar o viticultor a conhecer melhor e mais detalhadamente a área produtiva, permitindo aprimorar a qualidade e quantidade do vinhedo.
12

Le goût moisi-terreux du vin : contribution à la caractérisation cinétique et métabolique des moisissures associées à ce défaut organoleptique / Earthy-musty taste of wine : contribution to kinetic and metabolic caracterisation of fungal flora of grapes associated to this organoleptic deviation

Correia, Daniela 09 June 2011 (has links)
Certains microorganismes qui coexistent sur la vigne, peuvent avoir des effets bénéfiques sur la qualité du vin alors que d'autres peuvent être à l'origine de déviations organoleptiques. Dans la dernière décennie, dans diverses régions viticoles de France, plusieurs odeurs de moisi ou de terre ont été mises en évidence. La (-)-géosmine a été considérée comme étant le principal composé responsable de ce défaut. Des moisissures comme Botrytis cinerea et d’autres appartenant au genre Penicillium ont été souvent isolées à partir des raisins présentant l’odeur « moisi-terreuse ». Les effets de cette molécule sur la qualité des vins a motivé notre étude sur la caractérisation des moisissures responsables de ce défaut organoleptique. A partir d'échantillons prélevés en 2007 en Bourgogne, on a identifié, par des méthodes morphologiques et moléculaires, les moisissures présentes sur les raisins, Une souche de Penicilium expansum (25.03) et deux souches de Botrytis cinerea (BC1 et BC2) ont été sélectionnées. Sur baies de raisin, la validation d’un modèle prédictif des effets combinés de la température et de l'activité de l’eau, sur la croissance des champignons, a pu être mise en oeuvre. Elle a montré, sur de larges gammes de T°C et d’aw, que les modèles cardinaux avec inflexion peuvent être validés sur les produits agro-alimentaires en utilisant le gamma concept. L’étude de l’effet du cuivre sur le taux de croissance radiale et le temps de latence des moisissures, a été entreprise afin de mieux comprendre les mécanismes de résistance au cuivre des champignons et d’en déduire des résultats pour une meilleure efficacité des fongicides. Les moisissures testées ont montré une grande tolérance au cuivre, jusqu’à 4,7 mM pour P. expansum et jusqu’à 8, 2 mM et 7,3 mM respectivement pour B. cinerea, BC1 et BC2. L’étude des effets combinés des facteurs environnementaux et nutritionnels (T°C, CO2; Cu+2) sur la production de géosmine par P. expansum, a conduit à définir les conditions minimisant la production de géosmine. Ainsi, on a pu déterminer que le cuivre (composant actif de nombreux fongicides) est un facteur clé dans la production de géosmine par P. expansum. / Some microorganisms that co-exist on the grapevine may have beneficial effects on the quality of wine whereas others may be at the origin of organoleptic deviations. In the last decade, several mouldy or earthy odors have been highlighted in various wine regions from France. (-)-geosmin was found to be the major compound responsible for this deviation, along with Botrytis cinerea and fungi belonging to the genus Penicillium, since they were frequently isolated from “earthy-musty” odor grapes. The extent of damage on the quality of wines, motivated our study on the caracterisation of grape rot fungi. First of all, the microflora of grapes from Burgundy vineyards was identified (morphological and molecular methods), from samples prelevated in 2007. A Penicilium expansum strain (25.03) and two Botrytis cinerea strains (BC1 and BC2) were chosen for further experiments. The validation of a predictive model for the combined effect of temperature and water activity, on the growth of fungi on grape berries, demonstrated that cardinal models with inflexion can be validated on agri-food products, over a wide range of T°C and aw, using the gamma concept. Further we were focused on the influence of copper on the lag time and radial growth rate of moulds in order to better understand copper resistance mechanisms of the fungi and the efficacity of fongicides. The moulds tested showed a great copper tolerance, 4.7 mM for P. expansum and 8.2 and 7.3 mM for B. cinerea strains, BC1 and BC2 respectively. These results motivated our study on the influence of environmental and nutritional factors (T°C, CO2; Cu2+), using a Doehlert matrix, on geosmin production of the fungi tested. Copper (the active component of the “Bordeaux mixture”) showed to be a key factor in the increase of geosmin production by P. expansum.

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