CAUTION: The observations, conditions, and recommendations reported for Winchester, VA are provided as a guide to fire blight risk assessment only for the immediate area of the Virginia Tech AREC located six miles southwest of Winchester. Use of the information reported here for making orchard management decisions outside of that area is not our intent. Fruit producers outside of that area are encouraged to consult their state extension specialists for information similar to that provided here.
 |
| (Click to enlarge) |
FIRE BLIGHT: Above is a cropped graphic from the Maryblyt 7 program. Many cultivars still have much susceptible bloom. Here is a prediction for trees with first bloom open Monday, March 23, 2012. The temperature and rainfall data are current through Apr 16. Predicted weather conditions are shown for Apr 17-21. The components of fire blight risk are indicated in the columns labeled B (blossoms open), H (degree hours for epiphytic bacterial populations), W (wetting by rain or dew), and T (average daily temperature 60 F or above). The risk column shows that fire blight infection could have occurred with brief showers Apr 14-15 and could again be triggered Apr 17 by wetting from rain, a spray application, or heavy dew. After cooler temperatures Apr 18, infection conditions could again exist Apr 19. In high-risk situations, a protective streptomycin application is recommended ahead of predicted infection and with any spray applications of other materials. Be aware that risks could increase with unpredicted warmer weather and wetting. This graphic will be updated Apr 18. The weather conditions used in the predictive part of this graphic come from the Weather Channel for Winchester, supplemented by site-specific data from SkyBit Inc.
