Hello, community members. First time poster here who stumbled onto this site a while back and who has been trying to educate himself by digging into old threads. For quick background, I have a small (four-tree) “orchard” that I am attempting to establish in my backyard in mid-Missouri. A few years into this experiment and I have already battled deer and ant/aphids. I’m now wondering if I have been hit by fire blight and am hoping some more experienced orchardists can share their knowledge.
The first tree in question is a CrimsonCrisp on semi-dwarf rootstock (either G.214 or G.890) planted in the spring of 2021. It put out some blossoms this year but didn’t set any fruit. Leaves started browning at the top of the tree on the central leader, with the problem progressing downward. I have looked at many posts and extension articles on fire blight, but want to make 100% sure that diagnosis is correct before pruning off the strikes. You can see that there are several instances where the end of a shoot has a shepherd’s crook shape. However, some pictures of fire blight I’ve seen show the darkness starting at the stem and moving into the veins of the leaf. Is the discoloration on my leaves indicative or something else, such as scab or rust?
The second tree I’m concerned about is a Pixie Crunch (on G.41) planted in the spring of 2020. It put out a ton of blossoms for the first time this spring and ended up setting around 20 apples. This tree has several smaller branches that now evidence browning/drooping leaves.
Looks very much like fire blight to me from the pics you posted. Definitely not cedar apple rust. Trees are very susceptible to fire blight during the blooming period which also falls in line with your situation.
I sprayed dormant oil prior to bud break and then have sprayed a mix of multipurpose fruit sprays (some of the different Bonide products) and Immunox based on schedules I have found online for petal fall, first cover, etc. One thing that I did not spray for, sadly, was fire blight. Since I hadn’t noticed any strikes during the first few years, I had a false sense of security that maybe my small orchard was not in a danger zone. I have some Fertilome Fire Blight Spray (a streptomycin sulfate) that I will be vigilant about going forward. I have also found a guide for monitoring danger levels by tracking temperatures and rainfall.
Regarding my current situation, I will start cutting out strikes this afternoon based on guidance I’ve found online. But that brings up two more questions:
Guidance I’ve found says to cut back to a stub several inches below the visible damage. If there is damage on a lateral branch that goes all the way to the scaffold branch, do you then cut off the scaffold branch? I apologize if my terminology is incorrect/unclear.
In the instance where my central leader is infected, I will be significantly reducing its height. Where would you all recommend going from there? Should I cut back all of the other branches this winter in order to maintain balance and prevent them from competing with the now short leader or should I abandon the central leader concept and treat it more like an open vase going forward, preserving some of the growth on the other limbs?
