Sudden Large Black Spots on Mature Catts

[realoldbeachbum]

Catt Black Spots 09242021 — Postimages

Four days ago, a very large dark brown/black spot appeared one of my large Catts. The spot was about the size of a quarter, in the middle of the newest growth, and did not reach down to the pbulb or tip of the leaf. There was no sap oozing and no yellow leading edge. Also, it was NOT sunken.

I isolated the plant and tested it for CymMV & ORSV. It was negative for both.

Today, the same spots appeared on three more Catts that had been sitting near it, and the leaf on the original sick plant dropped in half and is now fully black.

Environment: Outside most days for the past 6 weeks in temps between 80 & 95 F. No full sun. Drenched with well water every other day if no rain. At the beginning of Sep (24 days ago) I gave them their first monthly dose of KelpMax/QuantamTotal per Rays recipe.

Based on pics from St. Augustine Orchid Society and other websites, I cannot determine for sure what this is; possibly Black Rot? (It rained for three days straight due to hurricane in the Gulf and was humid and warm.)

I cut the affected leaves, sprayed with Phyton27, then sealed the cuts with cinnamon.

Should I just put these in the trash to avoid further spread or is there hope for recovery?

Thanks so much, ROBB