Black spot on Cattleya

[Jeff214]

Hi,

I am having issues with black spots on a Cattleya hybrid.
I've noticed that it occurs when the new leaf is emerging out of the sheath and rubs against honeydew that collects there. I've tried wiping the honeydew as often as I can and it does seem to help - but not always. This often spreads to the flower sheath and ruins the spike.

I got physan 20 today and I'm hoping a foliar application will help.

This only happens on this Cattleya hybrid and its two divisions (one growing indoors, two outdoors, same thing). This is the second year I've had this one and it's happened both years. I'm not sure if this cattleya is particularly susceptible to fungal/bacterial infection, nutritional def., or diseased (or all)? I don't think it's a nutritional deficiency since it's been growing quite vigorously.

Beyond a physan 20 application, would you recommend anything else? Thanks.