ABSTRACT
Bacterial leaf blight caused by Pseudomonas marginalis pv. marginalis is the major leaf bacteriosis affecting the garlic crop. Little is known about the epidemiology of this disease and, for its evaluation, there is no illustrative scale describing the quantitative severity on the leaves. Thus, the present study aimed to elaborate and validate a diagrammatic scale for bacterial leaf blight of garlic. The study was conducted through the digitalization of 108 garlic leaves collected at the Federal Institute “Catarinense” – Rio do Sul Campus, showing different degrees of the disease. The images were processed to verify the percentage of injured tissue present on the leaves. Validation was performed by eight evaluators without and subsequently with the aid of the diagrammatic scale, using 30 garlic leaves showing different severity levels. The representative values of 21%, 37%, 45%, 56%, 63% and 85% severity were obtained to compose the diagrammatic scale. The use of the diagrammatic scale provided greater accuracy and precision of visual estimates for the evaluation of bacterial leaf blight of garlic.
Keywords
Allium sativum
;
Pseudomonas marginalis pv. marginalis
; patometry
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