Made available in DSpace on 2016-04-28T14:58:36Z (GMT). No. of bitstreams: 1 2008 - Fabio Mathias Correa.pdf: 2421517 bytes, checksum: 7f7f9e77fc6d68db6e05dbd9994c1e38 (MD5) Previous issue date: 2008-02-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The late blight of the tomato, caused by Phytophthora infestans (Mont) of Bary it is one of the main diseases of the tomato. However, the quantification of the severity of the disease, doesn't possess a standard method of evaluation and that, it can interfere in the comparison of results among and inside of experiments, once the scale of evaluation of the disease should be standardized. A diagrammatic scale should represent all variation of the existent disease in the field and to make possible necessary evaluations and perfected, independent of the existent differences among appraisers. Another important factor in the epidemiological studys, is the correct application of the methodologies of evaluation of treatments or cultivars. Therefore, the present work has as objectives: 1) to develop and to validate a diagrammatic scale for quantification of the severity of the late blight in tomateiro leaves and 2) to compare the use of AUDPC (area under disease progress curve), certain according to Shanner & Finney (1977), with the use of mixed models and mixed lineal models widespread in the selection of gen?tipos of resistant tomateiro to the requeima. Three diagrammatics scales were proposed for evaluation of the late blight in tomato leaves. The first scale, denominated scale-detailed, it was composed by nine values of severity intensity (0, 3, 6, 12, 22, 40, 60, 77 and 90%), the second climb, call of having scale-simplified, it was composed by seven severity values (0, 3, 12, 22, 40, 60 and 77%) and the third scale, of having James-modified, composed by seven severity values (0, 1, 5, 10, 16, 32 and 50%). For the validation of the scales, 24 appraisers accomplished two evaluations in leaves 50 tomato leaves with different severity levels, where the precision, acuracy and repetibility were appraised through simple lineal regression, analysis of variance of the mistakes and correlation coefficient. Among the proposed scales, two came as tools that allow a good precision and acuracy in the evaluation of the severity of the late blight in tomato leaves, being the detailed scale and the simplified scale. With relationship to the analysis methods, the use of direct AACPD, calculated by the sum of Riemann, and of mixed and mixed models widespread, it was verified that the direct use of AUDPC, doesn't get to describe all existent variation in the sample, probably for the great number of treatments. The use of mixed models widespread, that it considers the distribution of Poisson, it was shown more appropriate for to describe the epidemic caused by late blight in tomato, being more suitable in the selection of tomato cultivars seeking to the resistance the this disease. / A requeima, causada por Phytophthora infestans ? uma das principais doen?as do tomateiro. Para quantificar a severidade da doen?a, n?o h? um m?todo padr?o, o que pode interferir na compara??o de resultados entre e dentro de experimentos, uma vez que a escala de avalia??o da doen?a deve ser padronizada. Uma escala diagram?tica deve representar toda a varia??o da severidade no campo e possibilitar avalia??es precisas e acuradas, independente das diferen?as entre avaliadores. Outro fator importante no estudo epidemiol?gico ? a correta aplica??o das metodologias de avalia??o de tratamentos ou gen?tipos. Portanto, o presente trabalho objetivou: 1) desenvolver e validar uma escala diagram?tica para quantifica??o da severidade da requeima em folhas de tomateiro e 2) comparar o uso da ?rea abaixo da curva de progresso da doen?a (AACPD), com o uso de modelos mistos e modelos lineares mistos generalizados na sele??o de gen?tipos de tomateiro resistentes ? requeima. Tr?s escalas diagram?ticas foram propostas para avalia?ar a requeima em folhas de tomateiro. A primeira, denominada escala-detalhada, foi composta por nove valores de intensidade de severidade (0, 3, 6, 12, 22, 40, 60, 77 e 90%). A segunda escala, chamada de escala-simplificada, foi composta por sete valores de severidade (0, 3, 12, 22, 40, 60 e 77%) e a terceira, de Jamesmodificada, composta por sete valores de severidade (0, 1, 5, 10, 16, 32 e 50%). Para a valida??o das escalas, 24 avaliadores realizaram duas avalia??es em 50 folhas de tomateiro com diferentes n?veis de severidade, e a precis?o, acur?cia e a repetibilidade dos avaliadores foram avaliados atrav?s de regress?o linear simples, an?lise de vari?ncia dos erros e coeficiente de correla??o de Pearson. Dentre as escalas propostas, duas (escala detalhada e escala simplificada) apresentaram uma boa precis?o e acur?cia para a avalia??o da severidade da requeima em folhas de tomateiro. Quanto aos m?todos de an?lise, constatou-se que o uso direto da AACPD, obtido pela soma de Riemann, n?o conseguiu descrever toda varia??o existente na amostra, provavelmente pelo grande n?mero de tratamentos. O uso de modelos mistos generalizados, que considera a distribui??o de Poisson, foi mais adequado para descrever a epidemia, sendo mais indicado na sele??o de gen?tipos de tomate resistentes a doen?a.