I have no idea but if you don't get a reply on this forum you might want to post this on "pests and disease".
Karyn

I think it is just a poor clone so pull it out. I have had few caeruleas go like this over the years and it probably has a virus that could be transferred to other plants.

Here is a link that might be useful: Passiflora virus

My passion flowers that exhibit the yellow spots and dying leaves are frequently under attack by spider mites or other sucking insects. Check the bottoms of the most yellow leaves for what looks like dark dirt/dust and look for thin spider-like silk on the more tender new growth.

I find that some varieties are more susceptible to the mites than others (of which Incense is frequently defoliated unless I take precautions) while others don't seem as attractive.

~Chills

Sometimes yellowing is due to calcium, or maybe iron, deficiency.

My guess is powdery mildew. I get this quite often in the greenhouse during the winter when greenhouse is closed up tight and humidity and airflow become a problem. It starts as yellow spots usually on the older leaves and a week or two later the mildew spores will show on the upper surface of the leaves. You can pick off the infected leaves and throw them out or an easier way is to cut the plant back really hard (to about 6 inches with Caerulea). Give it a good shot of fertilizer and it will regrow nicely.