Fb risk from an infected orchard

I want to take some apple scion wood from a friend’s orchard in which the pear trees were severely damaged from fire blight this spring. The pears are neighboring trees to a 20 oz apple from which the scions will come. Do I face increased risk to transfer fb? The apples don’t show any strikes at all.

If you don’t have FB I would not take the scion wood. FB bacteria is there long before it shows signs of it. It is not anything you want when plenty of scion wood without FB is available. Get your scion wood from a cold place when possible since FB likes heat. In Canada I would imagine they have less FB.

I’m not an expert on anything, but I am awake enough to reply.

Here’s my middle of the night thoughts. Any introduction of plant material, including scion wood is a risk, much like any other investment. According to the American Phytopathological Society (APS), an organization dedicated to the study and control of plant diseases, fire blight overwinters only in a small percentage of cankers formed on branches infected the previous spring. They also state that the bacteria can only survive on healthy surfaces such as leaves and branches for a limited period (weeks) when the infection is going around.

I linked their page on fire blight at the end of this post. I thought it was informative reading. What I gathered from what they said is that if you collect the scion wood from that apparently healthy apple tree from a branch with no cankers during the normal winter gathering time, it would be as low risk as bringing in material from elsewhere. It should not contain fire blight bacterium.

But read the article for yourself; gather info from others, and make your own informed decision. You know my practical experience is limited.

APS page on fire blight.

My impression of fireblight is it is most places, just at a very low level. But, it in theory could help launch an infection if its really bad (doubtful as pear and apple tend to not get FB together based on my experience). You can always soak it in 10% bleach, that will likely kill any FB on the scions. Its generally a good practice on scions to do that to avoid any kind of disease transfer.

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When I say Canada I don’t mean that as a literal place to get scion wood from I’m using that as an exaggeration to say they don’t have much FB. Colder states have less FB than hotter high moisture states. Southern states have a FB problem northern states do not have.

Thanks for clearing that up, Clark. When I read your post last night, I figuratively scratched my head over why you’d suggest transporting plant material internationally. Then I thought that maybe your were under the impression that Chikn was Canadian. Now I understand the context of your statement.

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No I certainly would not suggest anyone do that unless they have an importer license. I type like I talk with the difference being the person reading cannot tell the context of the statement typed lol. That’s why I made sure to clear it up because I realized people would not understand what I meant. The danger of text messages and Internet forums is what you say people may interpret with a very different meaning. When I said “in Canada I would imagine they have less FB.” I did not say go there and get some scion wood I meant it like the weather there is unconducive to the bacteria’s optimal growth conditions.

Scott, Your impression is spot on in this orchard as the pears are 70% dead and apples show no strikes. How long of a bleach soak is needed?

Muddy, good link-very good info. thanks.

I don’t do very long, a minute or so and then a thorough rinse. Note I don’t soak generally scions myself, I have about every disease by now. But for rooting figs and grapes it significantly decreases the chance of mold so I may do the bleach soak.