Prosthechea cochleata black spots on leaves

[SouthPark]

MJG -- thanks for showing those pics. The mag-cal you provide will be enough already I reckon.

The twinkle definitely appears to be getting hit by something there --- like fungal activity maybe.

One approach to seeing if the issue could be sorted, is to unpot, divide into say 2 or 3 plants, and repot individually ------ and try a systematic fungicide on one or two of them, such as monterey garden phos. Or try say a copper spray on another plant. Or even thiomyl.

The old divide and conquer! Or divide and isolate into a few groups, and whack each group with a different substance, and maybe one of the systematics will come out to be really effective.

If the growing area has pretty good gentle air-flow most of the time, it can also help cut down or eliminate fungal issues. This is just assuming fungal issues.

One nice thing is that you have lots of bulbs there. Once we put whatever it is out of action, your plant can just grow new bulbs and leaves ------ and back in action again.

[MJG]

I like your divide and conquer approach for the Twinkle. I've order some thiomyl and already have 2 other types of non-systemic fungicide.

We'll see what happens. My growing area is good regarding air movement.

One more question. What does a cure look like? I'm imagining that the spotted leaves never lose their spots, it's just that new grow comes in healthy? Is that correct?

[Roberta]

Correct, and hopefully the existing spots don't continue to spread.