These two authors contributed equally to this study.
Development and validation of a set of standard area diagrams to aid in estimation of spot blotch severity on wheat leaves
Article first published online: 25 NOV 2013
© 2013 British Society for Plant Pathology
Volume 63, Issue 4, pages 922–928, August 2014
How to Cite
Domiciano, G. P., Duarte, H. S. S., Moreira, E. N. and Rodrigues, F. A. (2014), Development and validation of a set of standard area diagrams to aid in estimation of spot blotch severity on wheat leaves. Plant Pathology, 63: 922–928. doi: 10.1111/ppa.12150
- Issue published online: 13 JUL 2014
- Article first published online: 25 NOV 2013
- Accepted manuscript online: 16 OCT 2013 01:35AM EST
- Bipolaris sorokiniana ;
- disease assessment;
- foliar disease;
- Triticum aestivum
This study aimed to develop and validate a standard area diagram (SAD) set to quantify the severity of spot blotch, caused by Bipolaris sorokiniana, on wheat leaves. The proposed SAD set includes images of leaves with 11 distinct disease severities (0·1, 1, 5, 10, 20, 30, 40, 50, 60, 70 and 83%). The SAD set was validated by 12 raters without experience in evaluating plant disease. Lin's concordance correlation analysis of estimated versus actual disease severity (based on image analysis) showed that precision and accuracy improved for all raters using the SAD set in contrast to assessments made without it. The SAD set improved accuracy (coefficient of bias, Cb = 0·88 and 0·99, without and with the SAD set, respectively) and agreement (Lin's concordance correlation coefficient, ρc = 0·81 and 0·96 without and with the SAD set, respectively) of the estimates of severity. The severity estimates were also more reliable when using the SAD set (coefficient of determination, R2 = 0·76 unaided and R2 = 0·92 with the SAD set, and intra-class correlation ρ = 0·79 without the SAD set and ρ = 0·95 using the SAD set). The SAD set proposed in this study will improve the accuracy and reliability of estimates of spot blotch severity on wheat leaves.