Fire blight questions

I cut this back 6" below the fire blight strike w/bleached pruners and disposed of the diseased tip. Will that be enough branch removal to get rid of the blight? Our weather is supposed to dry out this weekend,we’ve had 6" of rain the past week, will that slow the fb? Am I safe?

Don’t know if you are safe and don’t think anyone else can say. I don’t have a lot of firsthand experience with fb. But if in your shoes I’d peel the bark off the cut off section and see if there is discoloration down to cut. If so cut off more and check again for discoloration. Do that until cambium is pristine. Maybe Scott or someone else with real firsthand experience could confirm that this might be viable technique.

Weather won’t affect fb already inside tree other than indirectly via growth rate.

What kind of plant is that and what is all of the white stuff on the leaves?

Wickson crabapple and I didn’t have my sprayer adjusted right. First tree on my spray cycle.


I had a huge FB problem last year. I cut out the blight using a method similar to yours and placed it in 30 gal trash bags and removed it from the orchard. The more blight I cut out, the more blight I saw. After cutting out a full pickup truck of FB, the Apple doctor told me to quit cutting it out until the epidemic was over and dry weather was expected for the next week or so. I followed his advice. From what I can tell, even the experts do not fully understand FB and best practice for removing the blight varies from region to region. Hope you get the stuff under control

Thanks, me too

I don’t know either what the real answer is, but I do know that I didn’t cut back far enough on the first dozen or so and it kept right on going (I probably cut back about 6" behind the first bit showing no infection). I then cut way back to the heavy wood and that seems to have arrested it.

Wow, deer fence, 6" of rain, heavy coating of Surround, and fire blight. Here I was complaining because there were some aphids on my sprout tips…I have it easy.

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Japanese beetles and aphids seem mild compared to the devastation fire-blight can inflict. This will be my third season without major issues with FB but I do not have any reasonable degree of confidence of being in control. Bill

FB is a problem that requires a lot of diligence and daily monitoring, and it also requires
staying away from varieties that are FB prone, so you’re never really safe. Whenever you see a
strike, it must be immediately pruned out, or it will continue to festure, and not only take hold of that
tree, but will also spread to other trees very fast. Once that happens, your last resort is to spray
with agrimycin, and trust me, that is not a pleasant task.

@rayrose, what are the difficulties with using agrimycin? Thanks.


Did the use of agrimycin help cure the shoot blight after the infection got started? I have only used it during bloom and I am very interested in its impact after the infection.

Agrimycin is a VERY toxic chemical, and extreme care must be taken not to inhale any of it. You must
wear long pants and long sleeve shirts, a hat and wear a respirator and eye protection. I’ve had to use it twice. The first time I did not wear a respirator and I paid the price. I was sick for a whole day. I had fb throughout my orchard and spent the entire season trying to keep it under control, and the agrimycin helped to do that. I finally traced the sourceof the innoculum to a Gala tree. Which I had to remove, and will never plant another Gala. The spread of fb was also helped by my using too much high nitrogen fertilizer, which kept encouraging new shoot growth, and the continuation of the fb.
I’ve learned that staying away from fb prone varieties and high nitrogen fertilizer will go long way to avoid fb in your orchard.
Trust me, you do not want to have to deal with fb. It will consume much of your time and set back your trees for the entire season.


I used to heavily feed with high N and had similar problems with new growth being attacked from various things. I have since switched over, the last two years, to a slow release N formulation, and the pest pressure and been balanced out to a great extent due to the lack of feeding sources. Plants are still healthy and some aren’t as filled out as I would like, but like the other thread, patience is a virtue.

I sprayed it multiple times during bloom with the proper protection but never had a health problem from it, One FB canker contains enough bacteria to infect an entire acre and its hard to locate and remove every single one. I believe the copper I sprayed helped to sanitize the bacteria somewhat, Since I did not experience a FB problem this year I added some extra N to try to get the trees to grow and fill in their space. So far only a few strikes this year after I thought I lost a big chunk of the orchard last year to FB. Based on my experience this year, Agrimycin is required before each rain during bloom when the average temp is 60 degrees or more to prevent the blossom blight.

Blueberry…is that the window of trouble…60 degrees or more with rain during blossom? If so, I’ll remember that. This is the first year I’ve had FB trouble, but I had it pretty bad. Could a light spray of copper be done during blossom without any damage. I’ve read about a lot of folks here spraying copper when growth was present. I’d be afraid damage, but maybe I’m overestimating the problems with copper. Do you think the potential good could maybe outweigh the bad? Would hydrogen pyroxide offer any help…what about iodine in a light solution?

I’ve done everything one could possibly do to prevent it, but I guess prime conditions presented themselves.
It really must be over, it’s rained here every day for nearly two weeks straight. Tommorrow in the 90’s. Powdery mildew has shown it’s face a bit and all this rain has prevented any sulfur sprays.
The clippers, Captan, sulfur and insecticides are at the ready. Just waiting for the opportunity.

I can only speak for how FB behaves in the northeast, but I imagine their are similarities everywhere in that it is a very unpredictable disease. On free standing apples and pears the strikes here usually don’t enter the big wood and kill the tree. A few scattered strikes usually doesn’t lead to a massive problem and the massive problems usually seem to happen all at once.

I’ve never lost large branches of apples but have had pears completely deformed by scaffold branches being killed. I’ve lost a few pears over the years, 3 or 4 in 25 years of managing thousands of pears and apple trees at many sites. However this and last year were the worst in memory for it so that figure may change quite a bit by this seasons end, I don’t know yet. It’s only been real bad at one site I’ve seen so far.

The urgency of immediately cutting out strikes is a controversial subject, btw. It is something that I can’t do given the time lapses between my visits of some of the orchards I manage.

Here is the best thing I’ve ever read about managing FB.


I agree with Alan that FB is very unpredictable. I do know its harder on young trees and it is harder on dwarf trees. Don’t believe you could spray copper during bloom, but a lot of research is centered around spraying lime sulfur as an alternative to strep for “orgainic” control. 60 degree during bloom with rain or wetting event is the trigger for the disease based on several computer models, If you cut the shoot blight out when its wet, you create a opening for the blight to attack the tree again. Not sure about peroxide or iodine.