Brown spots on white miltoniopsis buds

[aerides]

This plant grows under LEDs about 12 hours/day. I run a humidifier and overhead fan on low during the day (not directly over the plants). Daytimes, it's generally 75-77 degrees, with humidity between 45-50%, sometimes maybe a little over. I turn everything off at night and open a window on the far side of the room a crack to help take night temps down to 55-60 degrees in winter (the conditions in which these buds developed). Thanks for your thoughts.

[Ray]

Botrytis, perhaps?

[aerides]

This makes perfect sense. Never had the problem before. But that room can get muggy without my realizing it. Opening a window at night. Seems likely. Thank you, Ray.

[Ray]

After further consideration - if it's botrytis, the spots tend to be black, and gain a radiating "fuzzy" appearance as the fungus grows. Brown might simply be a result of water droplets and a a different pathogen.

[aerides]

Well, I read brown or black and the other characteristics you described are perhaps a later developmental stage? I will say that the spots in the pictures I looked up are tinier that these. Pinpoints and widely-spread. Mine are slightly larger but they are necrotic. I still suspect an unhappy coexistence between cool air and moisture, so I'm leaving the window closed and encouraging a slightly warmer nighttime period with lower humidity. Thanks again, Ray. I was trying to be letter perfect with the miltoniopsis because they are reputed to be impossible to grow inside the house. I've been growing that one for a year and it seems okay, apart from a little wrinkling post-repotting last year. The 60% humidity suggestion seems to assume a real microclimate for them (i.e., greenhouse). IOW, trying to provide pseudo-greenhouse conditions in a house probably doesn't work outside of a "Wardian Case." For most of the year this one seemed content with moderate day temps and watering at the slightest hint of being less than saturated. Pretty happy it's doing as well as it is. It's a pretty thing, and the fragrance makes it all worth-while.