Disease Severity Index Calculator

Compute foliar disease severity index from visual assessments using the standard 0-5 Horsfall-Barratt scale.

Class 0 plants (0% affected)

Class 1 plants (1-10% affected)

Class 2 plants (11-25% affected)

Class 3 plants (26-50% affected)

Class 4 plants (51-75% affected)

Class 5 plants (76-100% affected)

Tab to move between fields

Disease Severity Index (%)

20.57

Disease incidence (%)

60%

Mean severity (%)18.1

Total plants assessed50

Diseased plants30

Severity rating (1-4)2

How to Use This Calculator

Enter Class 0 plants (0% affected), Class 1 plants (1-10% affected), and Class 2 plants (11-25% affected).
Set Class 3 plants (26-50% affected), Class 4 plants (51-75% affected), and Class 5 plants (76-100% affected).
Review Disease Severity Index (%) and Disease incidence (%) (%).
Use Mean severity (%) and Total plants assessed to inform your decision.

Ad Placeholder