Double digit (00-99) method - Computation Compute overall severity after disease evaluation in the field using the double-digit scale (00-99). The first digit (D1) indicates disease progress in the canopy height from the ground level the second digit (D2) refers to measured severity based on diseased leaf area. Both D1 and D2 are scored on a scale of 1 to 9. For each score percentage disease severity is estimated based on the following formula: Severity (%) = ( (D1/9) x (D2/9) x 100) attribute entity variable_of scale_of method_of acronym