Hi Tim! nice to read you! I think there are more sources of fire blight bacteria in the general environment in the northeastern USA due to your woodlots and forests (with feral apples and native hosts such as Hawthorne) as contrasted with the treeless conditions around many eastern Washington orchards.
I agree! But still is fascinating to see whole areas without FB and others with FB, despite similar weather. We often make “false positive” predictions because of this = conditions are great for FB, but not FB develops because bacteria are simply not there. We have nice qPCR data throughout bloom to prove it. The bacteria (in the hypanthium) need to thrive in the nectary in order to reach numbers sufficient to switch on their virulence. Once this is accomplished you have an infection. Do you have a good reference for me on this specific topic? When I reviewed the literature, I only found a few things from Pusey. This might explain some cases. We can learn a great deal about interpreting models by looking at the weather data around the time that we are fairly certain that isolated infection events occurred. We can also look at when expected infections did not occur. It would be very helpful to me if any of you would share weather data including rainfall, hourly temperature (or daily temps) and especially leaf wetness readings. Please send data that covers days from first bloom to about 3 to 4 weeks after petal fall. Excel files are a real time saver. We’re Also looking for the same type of data…! Vincent
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