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edge graphicCougarblight Fire Blight
Risk Model
(Version 2001)
Tim Smith, WSU Extension

Four Day Degree Hour Total Thresholds
Potential Pathogen Presence Estimated by Fire Blight History(Below)

 LOW RISK

 MARGINAL RISK

 HIGH RISK IF FLOWERS PRESENT

 EXTREME RISK IF FLOWERS PRESENT
No fire blight in the area during the past two seasons.

 0 - 400

400 - 500

500 - 800

800+
Blight present in the region, but not near your orchard, last year.

 0 - 350

350 - 400

400 - 650

650+
Blight in your or neighboring orchard last year.

 0 - 150

150 - 300

300 - 500

500+
Active Blight strikes or cankers are presently in your or neighboring orchard.

 0 - 100

100 - 200

200 - 350

350+