Hey Mike, until the experts arrive…
A mushroom bloom like that is the result of a mycelial network under the bark that has been feeding on dead wood. Once the mycelia are stressed - usually by temp - they go into reproduction mode which is the bloom you see there. They are not hurting the tree. They are a sign that the tree has had some decaying wood for some time. (I grow mushrooms on purpose)
I don’t have experience recovering a tree in this condition, but from my other experiences (some likely will disagree), the inability of the tissue to protect/restore itself is related to a calcium insufficiency.
It looks like the mushrooms grew in the canker and then the spores washed down onto the trunk - it might be OK. The canker doesn’t look very good though. You can always start cutting it out and see how bad it is. I have a major ooze on one of my cherries which I am going to cut into soon.
The nature of it is that you do have dead wood. One of Nature’s remedies for breaking down dead wood is mushroom growth. (Kinda neat that ‘Nature’ will make food out of dead wood, but I digress) Spores don’t make mushrooms, they are just the beginning of the mycelial growth. Mycelial growth takes a long time 3-12 months, say. So the dead wood has been there for some time. And, of note, the tree is apparently compensating.
Only the tree can make new wood. The sap is Nature’s intelligent compensation to prevent moisture loss. If you remove the sap it would be good to coat the exposed wood with something that does the same thing. I think that since the tree is not showing signs of stress, it can make it…as long as the remedy is not worse than the disease.
I have (almost) had it with apricots. I say almost , because they are my favorite fruit. I don’t know what I am doing wrong…can’t seem to keep an apricot more than 2 years…usually less without it showing canker. I have had Harogrand, Goldcot, Harojoy , Haroblush, and they all seemed to develop wounds spontaneously… I ended up cutting them down. Now, having decided to give a try once again, my Moorpark especially… and Veecot to a lesser degree, have cankers again at the end of their second season. Some areas the branches had bark broken right down with heartwood showing and little specks of a pink-orange fungal growth ? Other areas typically sunken with red-brown wood underneath in small areas with or without amber ooze…often at the base of the tree around the soil line. All I can come up with is that from my reading and observation, my intuition is telling me these trees like relatively poor (low organic matter low nitrogen ) soil and hot , dry conditions. I can’t see how these trees are doing so poorly being babied as they are…unless that is exactly the problem… I don’t water them ever except when I plant them…but perhaps this area is just too wet (in spring and late fall, it certainly is not in the summer…often drought like conditions)…and perhaps these trees should not be encouraged too much with organic matter in the soil. …I suspect a sandier, poorer soil around the base of the tree might help avoid canker ?
it is my understanding…please do correct me if I am wrong…that gummosis and ooze is a symptom and not necessarily a disease…although I have not noticed actual canker in my plums or cherries (at least not the ones I have now…other cherries got chopped and burned)…some of them do get the ooze…but Apricots always seem to have the soft areas develop with dying red/brown wood underneath…which seems to be canker. The rootstocks that have been available to me for apricots are prunus Americana , and I don’t know what the ones were from local nursery, they didn’t list it on the tag. My present trees Moorpark and Veecot are on Mustang rootstock.
I have some canker spots on a couple of apple trees I will be dealing with soon. I plan to scrub the bark and wood with baking soda, and then coat the scaffolds with dilute latex primer. It is my hope that by sealing it in, I will deny the infection its food source.
Hopefully the mustang rootstock will add some disease resistance. I don’t know enough about it yet. I have a Black Ice plum on Mustang I just planted mid March, and I grafted a Nanaimo peach bud just below the plum graft. Time will tell if they stand up to the wet PNW Winter.