Mystery Problem with Bellina 'Ponkan'. Need Help.

[realoldbeachbum]

This tiny plant has been in my care for one year. About 6 months ago, tiny silver pitted indentations began appearing on both under & tops of leaves. I treated it twice with Bayer 3in1 Rose & Flower Spray (Tau-fluvalinate & Tebuconazole) thinking it was thrip damage, although no thrip were seen even with a magnifying glass.

The treatment seemed to slow expansion of the silver pitted areas. Now, however, a dense pitted area on one leaf has turned brown on the leaf surface. The brown area does not appear on the underside of the leaf -- only the pits. More worrisome, though, is a brown area in the crown.

It is in seedling mix with a layer of spagh and is watered every 10 days or so with weak K-Lite. Once a month it is drenched with Quantum Total & Kelp Max – same treatment as my other phals.

It was a TINY plantlet when I received it one year ago. I was not sure it would make it from the beginning, but it has hung on. (Yes, it is in a plastic wine glass – with good drainage.) Roots are bright green and healthy.

Environment: Inside under grow lights 11 hours per day, along with my other phals. Temps are between 70 F to 90F and humidity is between 50&70% with slow fan during heat of the day.

Any idea what might be the problem? Treatment?

Thanks so very much, ROBB

Phal bellina 'Ponkan' 05212022 — Postimages