Visual Inspection Disease Rates

Index of Disease Rate Infection (%) for Visual Field Inspection
Rate (%) Diseased Plants/Plants Counted Diseased Plants per Acre
1.0 100.0/10,000 180
0.5 50.0/10,000 90
0.25 25.0/10,000 45
0.125 12.5/10,000 22.5
0.05 5.0/10,000 9
0.01 1.0/10,000 1.8
0.005 0.5/10,000 0.9
0.001 0.1/10,000 0.18

The number of plants per acre is 18,000. The number of diseased plants/acre is calculated by "Rate times 180".