Escala diagramática para avaliação da severidade da mancha de Phoma do cafeeiro

Salgado, Mírian; Pozza, Edson Ampélio; Lima, Luciana Maria de; Pereira, Ricardo Tadeu Galvão; Pfenning, Ludwig H.

doi:10.1590/s1982-56762009000600010

Cited by 19 publications

(25 citation statements)

References 9 publications

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“…To assess the repeatability of estimates with both scales, 7 days after the first evaluation with the scale, we made a new sequence of the same coffee berries, and the same evaluators made a second visual estimation (Salgado et al. ; Custódio et al. and Santos et al.…”

Section: Methodsmentioning

confidence: 99%

Diagrammatic Scales for Assessing Brown Eye Spot (Cercospora coffeicola) in Red and Yellow Coffee Cherries

Paula

Pozza

Santos

et al. 2016

Journal of Phytopathology

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Brazil is the world's largest coffee producer. Brown eye spot (BES) (Cercospora coffeicola) is a major crop disease that can cause 15-30% production losses and decrease the coffee beverage quality. Although the influence of this disease on beverage quality has been studied, diagrammatic scales for assessment of the disease severity in berries are still unexplored. Thus, this study has developed and validated diagrammatic scales to assess the severity of BES. Two diagrammatic scales were designed to assess the disease in berries, which can be yellow or red depending on the cultivar. The scale of yellow berries had nine grades: grade 0: 0%; 1: 0

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Section: Methodsmentioning

confidence: 99%

Diagrammatic Scales for Assessing Brown Eye Spot (Cercospora coffeicola) in Red and Yellow Coffee Cherries

Paula

Pozza

Santos

et al. 2016

Journal of Phytopathology

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“…The diagrammatic scale proposed in this article like others, were constructed defining the intervals according to the law of "Weber-Fechner" (Custódio et al, 2011;Salgado et al, 2009), however, without following the same intervals of severity proposed by Horsfall and Barratt (1945) due to the disease's peculiarity. Among these characteristics, the maximum severity found in the field and the frequency intervals of higher concentration for the severity of the disease must be observed.…”

Section: Discussionmentioning

confidence: 99%

“…The diagrammatic scales have the function of helping in the determination of the leaf injured area, approximating the evaluation from the real. In general, the diagrammatic scales that have already been built up provide more precision and accuracy in relation to the evaluations without its use (Capucho et al, 2011;Salgado et al, 2009). Without using the scale, the evaluators tended to overestimate the disease (Belan et al, 2014, Custódio et al, 2011 and in relation to the hypotheses β 0 = 0 e β 1 = 1, were less accepted when scales in the evaluation of the disease severity were not used (Andrade et al, 2005).…”

Section: Discussionmentioning

confidence: 99%

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Diagrammatic scale for blister spot in leaves of coffee tree

Jhonata¹,

Marcelo²,

Mario³

2015

Afr. J. Agric. Res.

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Blister Spot is a disease transmitted through seeds. This characteristic of the disease reveals the studies of severity can offer more replies than the studies of incidence. Due to the inexistence of standardized for visual quantification of the Blister Spot's severity, the aim of this work was to build up and validate a diagrammatic scale for evaluating the severity of Blister Spot in coffee tree. Leaves in the field were collected with different intensities of symptoms disease, and electronically determined the real severity. Based on the frequency distribution of the severity values, and according to the law of visual stimulus of Weber-Fechner, the maximum and minimum limits, and the intermediate levels of the scale were defined. The validation was realized by eight evaluators that estimated the severity in 50 leaves with different intensities of symptoms. An evaluation without the aid of the diagrammatic scale was realized, and two others with its use, having intervals of seven days. The accuracy, precision, repeatability and reproducibility of the estimate were evaluated. The developed scale shows seven 0 (0%), 1 (0.1-3%), 2 (3.1-6%), 3 (6.1-12%), 4 (12.1-25%) and5 (≥25.1%). Using the scale proposed, the evaluators presented better levels of accurancy, precision, reproducibility and repeatability in the estimate, once compared to the evaluators who did not use the diagrammatic scale. The diagrammatic scale was adjusted to aid in the visual estimate of the severity of the Blister Spot in coffee leaves

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“…A escala diagramática pode diminuir essa subjetividade, aumentando a acurácia e a precisão das estimativas dentre os diferentes avaliadores, como já demonstrado em outros patossistemas (Martins et al, 2004;Kowata et al, 2008;Salgado et al, 2009;Sachs et al, 2011). No entanto, esta escala deve ser de fácil uso, aplicada a diferentes condições e idades da planta e produzir resultados reproduzíveis.…”

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Proposta e validação de escala para a ferrugem alaranjada da cana-de-açúcar

Klosowski

Ruaro

Filho

et al. 2013

Trop. plant pathol.

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RESUMOObjetivou-se neste trabalho elaborar e validar uma escala diagramática para a ferrugem alaranjada da cana-de-açúcar e comparar a sua eficiência em avaliar a doença com a escala da ferrugem marrom. Para elaboração da escala foram coletadas 120 folhas de uma cultivar suscetível à doença, e a maior e menor severidades encontradas representaram os extremos da escala. Os níveis intermediários foram calculados respeitando a lei de Weber-Fechner. A escala foi proposta com nove níveis de severidade: 0,06; 0,14; 0,36; 0,89; 2,17; 5,18; 11,87; 24,92 e 45,00%. Oito avaliadores realizaram a validação estimando a severidade de 120 folhas em três avaliações: sem escala, com a escala da ferrugem marrom e com a escala da ferrugem alaranjada. A escala elaborada foi mais eficiente para avaliar a doença, proporcionando um coeficiente de determinação (R 2 ) médio de 0,91 e ausência de erros constantes e sistemáticos. Com a escala da ferrugem marrom, o R 2 médio foi de 0,84, e três avaliadores cometeram desvios constantes. Com a escala elaborada, aproximadamente 92% das estimativas estiveram na faixa de variação de 5% do valor real, enquanto que nas avaliações sem escala e com a escala da ferrugem marrom, aproximadamente 78% e 84% das estimativas, estiveram nessa faixa, respectivamente. Palavras-chave: Puccinia kuehnii, Saccharum spp., patometria, severidade. ABSTRACT Proposal and validation of diagrammatic scale for assessment of orange rust of sugarcaneThe aim of this work was to elaborate and validate a diagrammatic scale to quantify the severity of orange rust of sugarcane and to compare its efficiency in assessing the disease with the scale of brown rust. For the design of the scale, 120 sugarcane leaves were collected from a susceptible cultivar and the highest and the lowest severity founded were selected as extremes of scale. The intermediate levels were calculated according to the law of Weber-Fechner. The scale was proposed with nine levels of severity: 0,06; 0,14; 0,36; 0,89; 2,17; 5,18; 11,87; 24,92 and 45,00%. The validation was accomplished by eight appraisers who estimated the severity of 120 leaves in three assessments: without scale, with scale of brown rust and with the proposed diagrammatic scale. The scale proposed was more efficient than the scale of brown rust to assess the severity of this disease, providing an average coefficient of determination (R 2 ) of 0,91 and absence of constant and systematic errors. With the scale of brown rust, the average R 2 was 0,84 and three appraisers committed constant errors. Moreover, with the scale proposed, approximately 92% of the estimates of the appraisers had been in the range of variation of 5% of the value of real severity, while in the assessments without scale and with scale of brown rust, approximately 78% and 84% of the estimates were in that range, respectively.

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Escala diagramática para avaliação da severidade da mancha de Phoma do cafeeiro

Cited by 19 publications

References 9 publications

Diagrammatic Scales for Assessing Brown Eye Spot (Cercospora coffeicola) in Red and Yellow Coffee Cherries

Diagrammatic Scales for Assessing Brown Eye Spot (Cercospora coffeicola) in Red and Yellow Coffee Cherries

Diagrammatic scale for blister spot in leaves of coffee tree

Proposta e validação de escala para a ferrugem alaranjada da cana-de-açúcar

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