The Maryblyt graphic below shows 9-day predicted temperatures and wetting, and the risk column shows the fire blight infection risk history May 5-14 and predicted risk through May 23. Today, May 15, the EIP (epiphytic infection potential) reaches 117 (117% of the required) and remains higher than 100 through May 23. Also, the average daily temperatures remain higher than 60°F, the required minimum for infection to occur, throughout this period. So all that is required for susceptible bloom and wetting as indicated above.
The BBS column is tracking predicted appearance of blossom blight symptoms from infection May 10 to predicted symptoms (113a) May 21. The CBS column at the right in the graphic indicates progression toward the appearance of canker blight symptoms on new growth, due to extension of overwintering cankers from last year, with canker margin symptoms (CMS) by May 15 and canker blight symptoms May 23. Canker advancement will not be prevented by a chemical treatment, and the presence of symptoms will indicate a build-up of inoculum which could become a factor in the event of a trauma blight situation due to hail injury, etc.
CAUTION: Always beware that risks can change quickly with unpredicted warmer temperatures and wetting. In high-risk situations, a protective streptomycin application is recommended ahead of predicted infection conditions, or with applications that cause wetting when all other infection conditions have been met. The weather conditions used in the predictive part of this graphic come from the Weather Channel for Winchester, supplemented by yesterday's site-specific data from SkyBit Inc.
