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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.
| Identifer | oai:union.ndltd.org:IBICT/oai:localhost:tede/525 |
| Date | 28 February 2008 |
| Creators | Corr?a, F?bio Mathias |
| Contributors | Carmo, Margarida Gor?te Ferreira do, Pimentel, Carlos |
| Publisher | Universidade Federal Rural do Rio de Janeiro, Curso de P?s-Gradua??o em Fitotecnia, UFRRJ, Brasil, Produ??o Vegetal |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFRRJ, instname:Universidade Federal Rural do Rio de Janeiro, instacron:UFRRJ |
| Rights | info:eu-repo/semantics/openAccess |
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