Spots on phal. Flowers

[Yourneedfulthings]

Came back to my greenhouse after 5 day absence and found many of my phalaenolsis flowers with brown spots as in the photo attached.
I keep humidity at about 60-70%, sunny days it gets up to 90's inside with roof vent and windows open.
I lost a fan recently so air circulation is uneven.
Question: are the spots due to poor circulation?, too high humidity? Or other.

Gathering knowledge. New fan is on the way.

[tucker85]

Botrytis. Air movement is the key to preventing it. Here's the AOS information on it.

https://www.aos.org/Default.aspx?id=120

[Yourneedfulthings]

Thank you. I read the article you suggested and all makes perfect sense. I hate to leave the greenhouse for so many days, left humidifier higher than normal anticipating very sunny/hot days and it rain/cloudy instead. Need more fans.

[tucker85]

I occasionally get botrytis on some flowers but it's not a fungus that seems to cause too much trouble and it's not something that will harm the plant. For some reason white phalaenopsis seem to get it more often than other white orchids.

[Yourneedfulthings]

Good to know that does not damage the plant. I sprayed the affected flowers with Phsan 20 and place them to dry fast in front of a fan. They seem unaffected by my intervension. Just to prevent spreading.
Thank you.

[NYCorchidman]

Botrytis like other stuff, is everywhere in the air basically. also as Tucker says, it causes unsightly spots on flowers but do not harm plants any more than that. No need to spray anything.
Once the damage is done, that's it.

By the way, I thought botrytis was a problem under cool and humid environment, so I find this rather interesting. Maybe they like heat also.

Lower the humidty, that is better than air circulation, because unless you grow plants out in the open, moving air inside a greenhouse even with windows open will still move the fungal spores around in the air.
When the humidity is low enough, you will NEVER see this spots on flowers.
For now, you are stuck with spotted flowers until they fade, but hopefully you will enjoy spotless white flowers next season.

[Yourneedfulthings]

Thank you. Glad to know spraying the flowers is not needed, it caused no futher damage.
Summers in my NC greenhouse are difficult, wish I could place my plants outdoor for the summer but that is not a option for me. I will keep humidity lower.Thanks.