Perplexing Catt problem - Orchid Board

boytjie · #1 07-10-2009, 09:20 AM

Hello all you Catt specialists. Problem has cropped up this blooming season which I've never before encountered. 90% of blooming sheaths/buds on my Catts are coming out black, with some strange webby/sooty material around the bottom of the sheath inside the leaves. The buds don't even get to the blast stage, since they emerge black and shriveled. I haven't ever seen this before, and I don't believe I'm doing anything different from previous years. Any ideas?

kinknstein · #2 07-10-2009, 12:13 PM

Don't know myself, but am interested to hear the opinions from other members...

Cookiemonster · #3 07-10-2009, 12:21 PM

Well sheaths drying out is normal for some in the cattleya alliance.
This is what I think might be going on---
the black stuff is either a form of mold... are you watering overhead?? If so water might be getting trapped inside the sheath area causing the mold and rotting out the buds.
Is your growing environment relatively stable temperature wise and such?

catwalker808 · #4 07-10-2009, 05:45 PM

Boytjie. I believe you had a period of thunderstorms several weeks back. If your gh had very high humidity then, coupled with the very high humidity outside at the time with not enough air movement. Maybe that created suitable conditions for water or excess moisture to persist and cause fungal growth which affected the sheaths. And what about too strong foliar fertilizer or other chemicals. Any very light green bands across the leaves or near the sheath area?
Just trying to give various options here.
While you're at it, the blackened material might be a symptom not the basic cause. Look under a magnifying glass or low power microscope if you have one ... for little crawly things with dirty feet.

Des · #5 07-10-2009, 06:13 PM

Boytjie some catts will put out a sticky sweet substance which sooty mould loves , I wash it off if is a problem . Also if I see a sheath drying out or going black I carefully open the sheath and tear it off dusting the wounds with some sulphur or cinnamon. Leaving the buds to develop without the sheath does no harm.
Interesting name you have there ,it is a South African term meaning "the main man" are you an expat ?

boytjie · #6 07-10-2009, 11:00 PM

Thanks for the input, all. Catwalker, I don't grow in a greenhouse; I grow indoors on shelves. The blackened sheath problem started a few months ago, as the plants were coming into blooming season. Sooty mold sounds like a possibility. I'll check closer for little beasts around the black stuff.

Des, I lived in South Africa for 12 years (Cape Town), thus the nickname. I miss the Cape every single day.

Des · #7 07-11-2009, 12:06 AM

Quote:

Originally Posted by boytjie

Thanks for the input, all. Catwalker, I don't grow in a greenhouse; I grow indoors on shelves. The blackened sheath problem started a few months ago, as the plants were coming into blooming season. Sooty mold sounds like a possibility. I'll check closer for little beasts around the black stuff.

Des, I lived in South Africa for 12 years (Cape Town), thus the nickname. I miss the Cape every single day.

Yes , Cape Town is A good place to live I lived there for some time ,but I could not handle the winter storms ,not that we dont have storms in PE ,but Cape Town seems to have the worst of it .