A standard area diagram set for assessing severity of eucalyptus bacterial blight caused by Erwinia psidii

Uma escala diagramática para a avaliação da severidade da seca-de-ponteiros do eucalipto causada por Erwinia psidii

ABSTRACT

This study aimed to develop and validate a standard area diagram (SAD) set to estimate the severity of bacterial blight of eucalyptus caused by Erwinia psidii. For this purpose, an eight-level SAD was developed and validated by ten inexperienced raters. Accuracy and precision of the estimates by each rater, with and without the SAD, were determined based on Lin’s concordance correlation coefficient. The proposed SAD improved the accuracy and precision of the estimates. The SAD set studied here is a useful tool in assessments of bacterial blight of eucalyptus for epidemiological research and breeding programs.

KEYWORDS
disease scale; disease severity; disease assessment; epidemiology