This plant may be somewhat susceptible to a couple of fungal or bacterial disorders. You might want to call your extension office to see if you can send some plant parts to a diagnostic lab for analysis.

I'd not continue spraying until you have an idea of what the problem could be. Fungicides shouldn't be used unless you're pretty sure of the disease agent, and then only sparingly.

I assume that you are well within this plant's hardiness range? Have you inspected along the trunks for any sign of bark splitting (freeze damage) or canker development?

Clearly if you've sprayed and sprayed and no change, then the product isn't labeled for what you have. Take a branch in to the Extension Office.

Dan

No freeze damage, splitting, physical damage.

Here's a link to some large pics. Perhaps that will help.

https://picasaweb.google.com/smokemup/ViburnumChindo#

Here is a link that might be useful: Chindo Disease

I see what looks to be one sort of bacterial spot on the leaf and some sort of canker on the stem. Your Extension Office should be able to ID that more precisely and recommend a treatment if its not too late, which you don't want to count on.

Dan

I'd be curious to follow up and see what you found out on this - our Chindo's have the same problem. Was it anything fungal?

hhaines, look at the date on the original post. I'd consider it unlikely that the OP is still around.