Diseased cottonless cottonwood???

I live in a west suburb of Denver, CO.
Cottonwoods are native out here, they were here before western civilization.
Now they banned the ones that put out the cotton though, and only sell cottonless types. But they're great for filling in areas and preventing erosion, as they grow about 5 feet a year.
So a few years ago, I planted 5 of these, to hold an embankment together. I planted them about 10 feet apart. They grew like crazy, as you can see.
http://lakewoodcolorado.net/cottonwood /
But now, the 2nd and 4th one ( every other one, which is odd ) has developed some kind of disease of the leaves and bark, and it's not something that is affecting the other 3.
On the diseased ones, the bark looks smooth, on the healthy ones it's thick and grainy like normal.
You can see the disease in the leaves, with the perfectly healthy one right behind it.
Does anyone know what's causing this, and the cure?
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http://forestry-dev.org/diseases/ctd/Group/Broad/broad3_e.html

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http://www.ext.colostate.edu/pubs/garden/02920.html
Looks like the Septoria fungus.
Now doesnt fungus need alkaline conditions?
I'm wondering of coffee grounds might make the soil acidic and get rid of it.
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IIRC it's the other way around. It's possibly due to CO2 released from decaying organic material, mixing with water to form carbonic acid.
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So alast know alalinity might help them?
That's odd, because I understand our soils here are already that way.
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Oh, little mysteries of life.
I might mention that the trouble with logic is picking the right premiss.
Most home made fungicides have sodium carbonate (base-alkali) in them.
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