Black Spots on Phalaenopsis Flowers - Orchid Board

Deena · #1 12-26-2016, 03:51 AM

One of my Phal orchids has bloomed recently and I've noticed that several flowers have these dark spots on the bottom petals.

I'm wondering if anyone has seen this before on an orchid? what is the cause of this? and how I can prevent it from happening?

I have some photos but the forum is not allowing me to post them on new account, so I'll try to add them later. -- Updated with pictures now.

Ray · #2 12-26-2016, 08:48 AM

Photos would be very helpful, but if the spots are black in the center, with a slight "flaring" around them, I'd say it's botrytis, due to high humidity and a lack of air movement creating an ideal environment for the mold.

orion141 · #3 12-26-2016, 10:45 AM

Agree, a picture would really help. If I had to guess I would agree with Ray about it being botrytis. Just make sure you have good air movement.

Selmo · #4 12-26-2016, 01:40 PM

Botrytis, is a naturally occurring flower petal fungus, that is always in the environment. As Ray said 'high humidity and lack of air movement' are the cause. Increase your air movement and that should help lower humidity. The spots will not go away, but you can stop more from forming. Phalaenopsis flowers are especially prone to this fungus.

jkofferdahl · #5 12-26-2016, 04:42 PM

Seeing the pics, I agree with Botrytis.

Deena · #6 12-26-2016, 06:56 PM

Thank you for the quick responses! I've looked up Botrytis and it seems to be the issue. I have also been seeing some fuzzy gray spots at the ends of the leaves and this seems to be caused by the same fungus. This winter has been more rainy and humid than the previous ones, which could be why I haven't run into this problem until the rains hit this season.

bil · #7 12-26-2016, 07:20 PM

Quote:

Originally Posted by Deena

Thank you for the quick responses! I've looked up Botrytis and it seems to be the issue. I have also been seeing some fuzzy gray spots at the ends of the leaves and this seems to be caused by the same fungus. This winter has been more rainy and humid than the previous ones, which could be why I haven't run into this problem until the rains hit this season.

Make sure you have a damn good fungicide to hand. I like Mancozeb.