Chestnut blight?

[cmiller]

I went a-googling <tree blight> and <tree fungi> to get a broader overview of tree diseases and how they manifest. I was struck by images i found of the effects of chestnut blight. The affected chestnut trees exhibit a very similar splitting/expansion of the bark around the bole of the tree, and the rampant shoots sprouting from the soil line. I read that there's something in the soil that prevents the chestnut blight fungus from penetrating beneath the soil, which is why the trees keep sprouting after the main tree dies back to the ground.

I imagined if this blight works as rapidly as the chestnut blight, but affects so many more species...oh, lawdy...

I found this webpage, which is all the more interesting considering your empirical experiences with chemical treatments of propiconazole and Agrifos, and because fungicides aren't supposed to be effective on Verticilllium wilt. 

I'd be interested to hear how the Agrifos is working out for you, now you've had more time to evaluate. Better/worse than propicanazole? Cost analysis for the two types? 

[Don Peters]

Trunk splitting...
I'm still not certain what causes the trunk splitting in white canker. In fact, I don't recall ever reading why any canker caused bark splitting. But from what I've seen so far when examining white canker fungus within bark and under a microscope, it appears that there is a race going on between the phloem (inner bark) and the fungal material - each wants to gain the upper hand and dominate. This seems to lead to thickening of the phloem. At the same time, due to lack of nourishment, outer bark can't grow. The result seems to be a split in the outer bark.

Something in the soil...
Yes, its entirely possible that something in the soil can kill the chestnut fungus. Same with white canker fungus, as my website describes under the "Lazarous plant". This "something" may be some sort of bacteriophage - a virus that kills specific kinds of bacteria. I think that's also the ultimate answer for eliminating white canker. But right now it's just a wish. The people who support bringing back the chestnut trees (I'm one of them), are banking on selective breeding to come up with a blight-resistant chestnut tree. But I'm not hopeful that that will work with white canker, as it seems to infect virtually all trees and shrubs. The only thing totally resistant to white canker I've seen so far is viburnum leaves (but the wood/branches are highly susceptible).

Chestnut web page...
What impresses me about this web page is the willingness to freely discuss and try a variety of disease treatment approaches. A while back I spent many many hours doing Google searches for information on Sudden Oak Death (phytophthora ramorum). While I found many web pages dealing with it, the vast majority were simply rehashes of existing information. I found almost no information about people trying to treat it by experimenting with various fungicides. I found no pictures of what it looked like under a 400x microscope. While this disease was spreading rapidly, I found no discussion or experimentation on exactly how it propagated/reproduced. Most sites seemed content to just publish pictures on what affected trees looked like, and how bad it was.

Agrifos...
I haven't tried Agrifos, so I have no idea on its effectiveness on white canker. I really only have the means to try one fungicide at a time. Right now I'm testing a Propiconazole and Pentra Bark combination as a "trunk drench". I've tried about 4 or 5 treatments over the summer on my trees and shrubs, and on two of my relative's trees and shrubs. Experience so far shows it to be successful, so I plan to publish details on this website soon. Possibly next summer I'll try something else, such as Agrifos and Pentra-Bark. My goal is to find something that is relatively low cost, easily applied, doesn't damage the trees, and is not a threat to people, groundwater, or animals.