Fire Blight Situation at Kearneysville


Caution: The observations and conditions reported for Kearneysville, W.Va., are provided as a guide to fire blight risk assessment and symptom development for the immediate area near Kearneysville, West Virginia. Use of the information reported here for making orchard management decisions outside of that area is not our intent. Fruit producers outside the eastern West Virginia area are encouraged to consult their state extension specialists for information similar to that provided here.

Fire Blight: Here is a graphic from the Maryblyt program that can be used to summarize the current fire blight situation at the Kearneysville TFREC. This is a prediction for later cultivars with open bloom. The components of fire blight risk (R) 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 temperature and rainfall data are current through Thursday morning, May 8, 2008. We've had three infection period for fire blight so far this year. The first occurred on Saturday/Sunday April19/20, the second occurred on Friday/Saturday April 25/26, and the most recent on Saturday/Sunday May 3/4. Early symptoms for the first infection are forecasted for Wednesday, May 7, this week. Symptom development from the first infection are being logged in the BBS column - when BBS = 100a begin scouting for first symptoms of blossom  blight. Begin scouting now and continue weekly for the next four weeks. Watch the BBS column for 100b to begin scouting for symptoms from the second infection period. This is likely to be early next week (see 96b in the BBS column below for the prediction for May 12).

The five-day forecast for the rest of this week, May 8 -  12, shows a significant enough warming trend to keep EIP above the threshold of 100 for today.  According to today's forecast, it appears temperatures will favor fire blight infection with today's rain. We've been forecasting this day as a potential fire blight infection since Monday. Conditions after today show that fire blight risk is moderate, although this could change rapidly to "infection" with slightly warmer temperatures than those forecasted for May 9 and May 10. With cooler conditions on May 11 and may 12, fire blight risk will subside considerably until warmer weather returns. Bloom may be finished by the time warmer weather returns, so it is likely that there will be only one or two more updates to this page. Look for the next update on Monday, May 12.

When using these predictions, be aware that risks can increase quickly with warm temperatures and unpredicted wetting. See the Fire Blight "fact sheet" for more information and disease photos.  

 Maryblyt "FAQ" (answers to frequently asked questions about Maryblyt.

Here is where I get my predicted temperatures:
AccuWeather - Kearneysville, W.Va.

Updated: 05/08/2008 08:24:33 AM