Hypoxylon Canker? :(

[Matias]

So. I have been working towards a solid diagnoses of what is eating the live oaks on the peninsula, and yesterday, I think I found my smoking gun.

 

[Reach]

I'm not sure how Hypoxolon presents on Live Oak, but that looks like a possibility to me. Or at least something similar.

 

[Evo]

In my experience with hypox is it’s generally a secondary issue

 

[Matias]

In my experience with hypox is it’s generally a secondary issue

100%

I am sure that the four years of hard drought were a major factor, plus nearly all the soil I see around here is massively compacted. The worst of what I see are in densely planted stands of only the one species. They were basically set up to fail unfortunately.

 

[Bendroctanus]

The 1st picture looks like it for sure. Indeed, it is an opportunistic fungus that takes advantage of a tree when stressed. From what I’ve been told, most susceptible trees have it and live with it, the tree’s natural defenses keeping it at bay to a small colony, until a stress event comes along and it ravages the vascular system. It’s been a doozy round here…

 

[Reach]

The 1st picture looks like it for sure. Indeed, it is an opportunistic fungus that takes advantage of a tree when stressed. From what I’ve been told, most susceptible trees have it and live with it, the tree’s natural defenses keeping it at bay to a small colony, until a stress event comes along and it ravages the vascular system. It’s been a doozy round here…

That's interesting to learn, I did not realize it was typically secondary to some other stressor. I suspect that is why we see it so often around here killing Pin Oak trees specifically, because at this point pretty much every one of them has Bacterial Leaf Scorch.

 

[Matias]

It particularly thrives on drought. The research from Texas A&M describes what I'm seeing pretty well.

 

[Bendroctanus]

That's interesting to learn, I did not realize it was typically secondary to some other stressor. I suspect that is why we see it so often around here killing Pin Oak trees specifically, because at this point pretty much every one of them has Bacterial Leaf Scorch.

Pin Oak is favored prey around here to Hypoxylon. I think your observation is accurate.

 

[Bendroctanus]

It particularly thrives on drought. The research from Texas A&M describes what I'm seeing pretty well.

That tracks. We’ve had tons of drought conditions in the last few years, and any of the long time local guys say it lines up with a bad drought from 12ish years ago. Hypoxylon doesn’t always kill right away, from my experience. It many cases it can take 5-10 years depending on the tree itself and conditions that year.

 

[Treezybreez]

Looks like Hypoxylon to me. Around here Red Oak suffer the most from it followed by White Oak. Western Live Oaks are in the Red Oak family I believe.