Diagrammatic scale for assessment of grapevine rust

A diagrammatic scale with six levels of disease severity (1, 5, 12, 25, 50 and 75%) was developed to assess grapevine (Vitis spp.) rust severity, caused by the fungus Phakopsora euvitis. Two versions of the scale, in black-and-white and in color, were validated by seven raters without previous experience with grapevine rust, who estimated the severity of 30 grapevine leaves showing rust symptoms, with and without the use of the scales. Precision and accuracy were determined by linear regression, relating the assessments using the scales to actual severity. Actual severity was assessed with the software ASSESS®. Using the diagrammatic scales, some raters were able to improve precision and accuracy. The color scale provided slightly more precise and accurate estimates than the black-and-white scale.

Bibliographic Details

Main Authors:	Angelotti,Francislene, Scapin,Claudia R., Tessmann,Dauri J., Vida,João B., Oliveira,Ricardo R., Canteri,Marcelo G.
Format:	Digital revista
Language:	English
Published:	Sociedade Brasileira de Fitopatologia 2008
Online Access:	http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1982-56762008000600006
Tags:	Add Tag No Tags, Be the first to tag this record!